1. Introduction

The course consists of two main elements: firstly, theory instruction given through a PowerPoint presentation, including a standard CPCS theory test, and secondly, practical instruction on the machine, followed by a CPCS practical test. Upon successful completion and passing of all elements, the candidate will be given a Red CPCS Trained Operators card.

Operating a crusher is a 360-degree process and follows ongoing inspection of the machine and its components. A daily pre-start involves starting the machine and progressing to running, followed by a check after operations have ceased to see what has been damaged during the process. The modern-day crusher is a rear articulated boom type that is hydraulically powered and has a self-propelled track.

The CPCS A42 Crusher course is designed to provide candidates with the skills and knowledge required to operate a crusher in a construction environment. The course consists of both theory and practical instruction, including an introduction to the machine and inspection before operation, safe and competent operation of the machine, cessation of machine use, and inspection after completion of operations. The duration of the course is 1-2 days, and upon successful completion, the candidate will be issued with a Red CPCS card.

1.1. Course Overview

The ultimate decision and responsibility should lie with the director or person responsible for health and safety and the legal or competent level. This person should then identify training needs for the workforce in question.

The National Plant Operators Registration Scheme card has now been classified as a red trained operator card. This shows a step has been taken in enforcing more formal training qualification. It provides evidence that the workforce in the extractives and mineral processing unit in industries are operating plant properly and safely.

People who may be interested in further details on crusher courses would be plant managers, material production managers, plant flow material processors, and persons involved in health and safety. People involved in training assessment of operators using crushers and screeners. This includes SVMs.

For those who have attended the Red or Blue Card courses, the content will contain some new information. This is taking into account that these people have already obtained an NVQ unit or a formal qualification before the new schemes introduced in 2013. It may also be beneficial for those who require a formal qualification for the first time.

This is a training course for all those involved in the operation and maintenance of mobile impact crushers, including screeners/scalpers on mobile plant. It will enable delegates to carry out their work more safely and efficiently.

1.2. Importance of Crusher Training

Health and Safety is at the forefront of all industries within the UK. The CPCS A42 course provides an extensive amount of knowledge on the importance of health and safety whilst operating and carrying out pre-operational checks on the machine. Implementing and understanding the knowledge and significance of this throughout practical use in the workplace will lower the risk of harming oneself and others around them. Completing the CPCS A42 Crusher course is an effective way for those within the demolition industry to progress as the skilled operative can work towards attaining the NVQ in Plant Operations. This is a qualification comprising of various units including the one studied. Successful candidates receive a Red Trained Operators card and an NVQ certificate (if successful in gaining NVQ qualification) which is endorsed by the Construction Plant Competence Scheme, a widely recognized and highly recommended qualification valid for 2 years typically required as proof of competence to comply with regulations and approved codes of practice. This will help enhance work and job prospects in the current economic climate. Finally, the course is vast and ever-changing in its content, by attending the CPCS A42 Crusher course, it ensures that the knowledge and the qualification of the candidate is up to date and current in accordance with the new regulations and legislations set within the European Union, British Standards and HSE in the construction and demolition industry.

1.3. Course Objectives

The main aims and objectives of the crusher training course are to offer knowledge and practical training for candidates on understanding the machines, operating the machines, conducting machine maintenance and inspection, performing machine transportation and to provide an understanding of the requirements for the CPCS assessment. This can be achieved through a combination of classroom-based training, eLearning, practical experiences using the simulator and virtual reality environment, and practical experiences in the mill and the training grounds. The course also aims to prepare candidates for taking the CPCS technical test. This will be achieved by utilizing the CPCS Technical test criteria as a guideline for the course itinerary. This will provide candidates with the knowledge and guidance to be able to attain confirmation of the red CPCS trained operator card within the 2-year VQ (Vocational Qualification) period. It is strongly recommended that all candidates involved in operating and maintaining crushers on construction sites take this course to further their understanding and to confirm they are working to best practice in the industry for the benefit of themselves, their employer, and the industry.

2. Crusher Basics

2.1. Understanding Crusher Components

2.2. Types of Crushers

2.3. Crusher Operation Principles

2.4. Safety Precautions

3. Crusher Maintenance

Regular inspection of metal parts (e.g. bucket teeth, dumper wear plates, and drilling components, etc.) to ensure they are unlikely to break off and enter the crusher feed. The strategic placing of electrical magnets and/or the installation of metal detectors to prevent damage to crushers and screens is the best way to ensure the machinery’s life. This helps to maintain good metal utilization and a high-quality product. Cleaning and housekeeping work around the crushers will help to avoid any potential risk of a fire, slipping and falling, possibly being struck by falling objects, and explosion. Maintenance of drive systems and the replacement of worn-out parts on these systems. Lubrication on all chains, V-belts, and drive belts will be an effective way of stopping any long-term damage. The maintenance of and testing to optimize the operating speed of the crusher often becomes the defining factor that links product quality, customer satisfaction, and profitability. Step 4. Step 3. Step 5. Step 6. Step 7.

3.1. Regular Inspection and Lubrication

Inspect and check all clear orifices for obstructions monthly. Check differential pressure across the bearing housing. If the pressure is less than eight pounds, an oil issue could be indicated. When an oil issue is indicated, the oil system should be serviced. When an oil and a filter change are recommended, clean the tank and change the oil, clean the filter bowl, and change the filter elements. When an oil change is due, the tank should be completely drained and then flushed with a minimal amount of clean oil to prevent contamination. Drain and refill clean oil tank with new oil. Coat the upper threaded portion of the bowl and the threads of the adjustment ring with a sufficient amount of SFL-90 (thread lubricant). SFL-90 should be added periodically to the threads and the upper portion of the bowl, using the recommended amount. Clean the bearing housing and apply a grease compound monthly. Apply a proper amount of grease to the spherical bearing, the tapered bearing, and the eccentric bearing, as directed in the manufacturer manual. Any of the following abnormal conditions and noises are a sign the crusher is not operating at maximum performance: Lateral or vertical movement noted in the spherical bearing. The eccentric bearing is dry and has lost its galling action. Metal to metal contact in the tapered bearing area. It is stressed that these symptoms are only a sign of the problem and not necessarily the point of component failure.

3.2. Troubleshooting Common Issues

The majority of the common problems discussed in the next section will be with the Vibratory Grizzly Feeder. These problems may occur because the feeder has been unused for a period and the operator has allowed the material to become lodged in the hopper, or simply from the operator allowing oversized material to enter the feeder. Either of these can cause a restricted flow of material, the feeder to start and stop, or a full-on stop of the feeder. All these symptoms will generally have the same outcome: damage to the feeder’s coil motor. At the first sign of any of these problems occurring, the operator should shut off the feeder and begin to remove the material, as continuing to run the feeder will cause extensive damage. To remove the lodged material or foreign objects, the feeder and hopper assembly should be turned off and isolated, then start slowly dismantling the hopper and removing the material piece by piece. If there is only a light buildup of material and the feeder has not yet been affected, opening the grizzly section and isolating the feeder may allow the material to move down through the crusher and into the next chamber. But do not do this if there is a large amount of material buildup, as it must be evenly spread around the whole chamber to allow removal. Next, try adjusting the feeder rate and increasing the feeder run time. This should cause a transfer of material to occur and begin to clear the problem. If the feeder has already stopped or started to show signs of erratic movement, shut off the power before any further damage is done. Coil motors can sometimes be cleaned in white spirit and left to dry before further inspection. Another common problem is material flow within the crusher. This can be caused in several ways. For example, if the material being processed just after a startup or shutdown of the crusher has high moisture content. This wet material can build up in the feed tube and cause a blockage, which in some cases will cause the feed tube to be forced upwards and result in sealing rings coming out of place or damage to the head. If the crusher carries on running empty, the motor will spend unnecessary time crushing the walls of the inner part of the crusher, and this will most likely cause a complete motor burnout.

3.3. Replacing Crusher Parts

– Another relatively simple way of part replacement, which provides a faster alternative to bolt-on part replacement, is part fitting using a frame. This entails fabricating a frame which can be temporarily set up around the crusher to aid part fitters. This can be a simple A-frame type frame, and the new part can simply be hung from the frame and swung into place. An example of where this type of replacement can be used with added benefits is part replacement on a cone crusher. New cone and mantle can be lowered into place piece by piece using the frame and lifting apparatus. This is a slower, however more technical method of part replacement, and it can actually be carried out piecemeal whilst the part is still in operation, saving partial loss in production time. Step parts can also be fitted using this method. This type of part replacement once complete ensures a new part has been correctly fitted, and the setting can immediately be checked using the new part.

– The use of “Bolt-on” parts. Ensuring the crusher is in operation, remove the centring boss, the retaining pins, and the damaged part. On doing this, it is expected that the damaged part will fall out and a new part can be fitted in its place. This type of part replacement is very quick, has no hidden or additional costs, and it is easy to ensure the new part has been fitted correctly. This is important for improving and maintaining the quality of the crushed product. Another benefit of such part replacement is there is no need to realign the crushing tool, and there are no parts to be saved and re-used. This is very important, and crusher operators should take note that some part re-use can lead to part failure and/or an inability to remove the part to be replaced.

An important part of maintaining a crusher, and in turn its performance, is part replacement. This can seem like a daunting task for a first-time crusher user, however there are numerous types and ways of part replacement, each necessary and each with their own benefits. Usually, the loss in production is so small that this can be done in lieu of other maintenance. Some simple and effective ways of part replacement are:

3.4. Crusher Cleaning and Housekeeping

1. Ensure power to the crusher is switched off before doing these activities. 2. Check to make sure there is no material in the crusher before opening the cleaning and inspection doors. Often this material can be a lump of oversize which could bog down the crusher and actually damage the jaw on the crusher. This material must be removed before proceeding. 3. Open the crusher to ensure that the sample material ejected from the jaw is free from impurities. If not, these can be removed with a wire brush. Often these impurities have been the cause of damage to the jaws or cone. By removing them, the likelihood of damage occurring again is reduced. 4. Using a good quality bristle brush, thoroughly clean the entire surface of the machine. Pay particular attention to the housing and the area below the crusher where material may build up. This built-up material has the risk of blocking the machine during its operation. By using a methodical housekeeping approach, the removal of this material can eliminate unscheduled downtime from damage to the crusher.

You need cleaning of your crusher at regular intervals to keep it working effectively and efficiently. Follow these steps to clean the soiled crusher correctly:

4. Crusher Operation

Often today many crushers are establishing control of the material through product outlets. This is done by adjusting the CSS at which the crusher will operate. Usually, a higher standard of product is produced when the machine runs with the crushing head at a slightly smaller CSS, as the crushing action imitates a milling effect more than a breaking action. This is penalized with a lower throughput of material and a higher kWh/t power rate, due to increased crushing of recirculated materials and the over crushing of interparticle beds, which fully utilizes the crusher’s potential. By contrast, a higher CSS setting will have the inverse effects. This is seen to be more effective for crusher maintenance and constant crushing conditions over the life of the mantle and concaves being used. Fines production is increased, often…

Sometimes a job can be compromised due to wet material or the need for the production of certain sized material. If the moisture content or the percentage of fines in the feed increase, higher starting frequencies and amplitudes are often needed to fluidize the material or to increase the percentage of the valuable product in the last case. This will be apparent by an increased power draw on the machine, and it will have to be monitored and adjusted to suit with the changing conditions. Typically, as the moisture content increases, it is better to run the crusher with a higher starting frequency and a decreased CSS to displace the wet fines. This operation is most efficient under these conditions, but it will require constant adjustment to suit the changing conditions throughout the life of the crusher. A variable flow fed by a CPCS Certified competent operator is key in maximizing the effectiveness of the operation, minimizing fuel burn and wear rates on the machine.

The output from the primary crusher and the finer material from the secondary crusher is determined by the gap in between the two crushers. This can be done using an impactor, for example a grizzly. The grizzly is a set of parallel bars at the bottom of the chute. It has the function of allowing the material in the product to go through to the next stage in the process. Meanwhile, the grizzly bars are able to remove any material that is already the size required.

The operation of a crusher is a complex process with many variables to consider. Any one variable can make the difference between profitable and non-profitable business. This is why before the machine has even been started, the following factors should be taken into account.

4.1. Start-up and Shutdown Procedures

If the crusher is to be fed directly by a conveyor, all dangerous parts of machinery should be suitably guarded. Failure to replace guards (on crushers and conveyors) after cleaning or maintenance work is a major cause of injury on these machines. Fig. 2: Excavator feeding mobile stone crusher. Blocked crushers causes. The written example of the learner’s theory test is very similar to the vision shown in the video. This is to help prepare the learner for the time from now to when he will take his theory test. The learner should be familiar with the types of crusher and the triggers on these to reduce blockages, and the most efficient methods of unplugging one will likely be an integral part of future training. The learner should use the information in this video to enhance his theoretical knowledge in the subject matter, and each topic covered in theory should be visibly recognizable in the practical application.

4.2. Loading and Feeding Techniques

This section will outline several methods on how to feed material into and across the jaw crushers which will work best for your products. 1) Feed hopper to the jaw crusher is always preferred, but with the use of a flared type hopper and steel plate over the cone will reduce the damage to the crusher and apron feeder. 2) It is not good to try and feed a jaw crusher with a material that is erratic in size, shape, and hardness, and this may damage the crusher. An example would be an oversize material produced from blasting which will not easily pass through the crusher or when the maximum size of material will a jaw and a soft material often an impact crusher will set the best result. 3) On arrival at the crusher, there is often a desire to be able to break the material into finer products, and the best method to that is to use a double decked vibrating screen following a good transport by apron feeder into the grizzly. 4) At all times, the minimum number of fines required in the product should be the aim of the operation, and to achieve this, close attention should be paid to the CSS. This can be done by installing a weigh scale either on the feed conveyor or on the crusher.

4.3. Adjusting Crusher Settings

It is highly recommended that an initial inspection or level control be carried out with set adjust on the crusher. At some point, on a current or future size which you want to attain in the aggregate, for example, certain an aggregate size has been verified, the check to see if the current setting is too slow or fast can be made. This can be done more efficiently and effectively than making sporadic and untargeted control changes over a period of time, thus causing potential damage to the crusher.

At the start of his shift or prior to starting crushing operations, the crusher operator must activate the Emergency Stop System to prevent the release of uncrushable material and release the isolation system to allow operation of the crusher. Then, he will start the primary machine and turn on the amp meter on the main motor. The crusher operator will then make an initial pre-start visual inspection, walk around check, and run a crushing and manual feed. The crusher operator must inform the on completion of the pre-crush examination. The amp readings or data are used as a baseline for tracking future readings, and the data should be recorded and stored. Trends should be developed with the operator being informed of them. This is invaluable in identifying and tracking problems and trends with bearing and liners. Amplifier is a mask to better reliability-centered maintenance and for identifying the location where control changes have been made.

The main purpose of the crusher is to reduce rock and rubble to a smaller size. This will enable the material to be processed into valuable products through material. At all times, the crusher will be working in a safe and controlled environment, such as an allocated crushing area, with on-site materials tipped or delivered from site to the work area.

4.4. Monitoring Crusher Performance

3. Automating the Change of CSS with IC Automation. An automated setting control system can be used to optimize the crusher’s performance at varying set levels. An online system is possible. This will continually monitor the real-time loading of the crusher and if the setting should be changed to deal with an abrasive type of rock, or directly to control the overall reduction of the setting to maintain increased utilization and maximize the product shape and gradation.

2. Using Strain Gauges on Frame, Rate, and Stroke Transducers. This method is more expensive and presents a higher level of complexity, but it is a very effective way of monitoring crusher setting on a constant real-time basis. This will optimize working efficiency, reduce energy consumption, and maximize crushing utilization throughout the entire life of the concave and mantle. This should give more accurate data of the real-time usage of the crusher and with the possibility of making quick adjustments, leading to an optimized process.

1. Plant Checks and Visual Assessment. CSS can be changed by a process of visual inspection to compare the setting with a known value. This can be time-consuming and very difficult to manage changes in setting during operation.

Monitoring crusher performance appropriately involves effectively measuring the closed side setting (CSS) in order to be able to maintain the setting and maximize the utilization of the crushing process. There are a number of methods and the choice will depend upon the application and the individual preference, these include.

5. Crusher Safety

When working with plant (i.e. crusher) to use a form of work equipment or machine which is capable of causing death or serious injury, you must use an approved CPCS Competent Operator or a CPCS Competent Operator – Integrated Training and Assessment (crusher operations). The operator must be competent in using the specific type of plant and machinery being used. They will be deemed competent once they have a skill card to prove this. It is also widely recognized that there is a shortage of skilled workers or a reduction in skills amongst existing workers. So, a structured approach to training is a crucial part of making sure the operator is competent. Skills can be obtained through the various National Vocational Qualifications (NVQ) or the Construction Plant Competence Scheme (CPCS). This training teaches the operator how to use the machinery correctly and safely.

When you are in the business of using construction equipment (i.e. road building, forestry, construction, or other off-highway vehicle industry), you need to effectively manage and control risk. Workers face many risks in today’s workplace, with many being injured or killed. Hazards such as equipment operation, vehicle overturn, highway work, and maintenance and repair are a major cause of deaths in this industry. So, being equipped with proper training in managing and controlling risk will enable you to better manage your own and others’ safety and lead to fewer accidents and injuries.

5.1. Personal Protective Equipment (PPE)

Personal protective equipment (PPE) is defined as clothing and equipment designed to protect the wearer from injury or illness. PPE should only be used as a last resort; its use cannot be considered as the primary means of protection. PPE should be used in conjunction with other methods of hazard control. The use of PPE will not prevent an accident but can lessen the severity of an injury or illness. All PPE must be last examined and its effectiveness assessed. The assessment must take into consideration the work activity, the environment it is used in (is the terrain very slippery, is it very muddy, is it very sharp, etc.) and the user. Where PPE is provided for employees, it must be maintained and replaced at no cost to the employee. A failure to use PPE may result in disciplinary action being taken. All PPE should be suitable for its purpose, it must be CE marked, and a supplier’s declaration of conformity is available. PPE should be of a proper fit, it should be issued based on body size, and it must be comfortable to wear. If the user is uncomfortable due to the PPE they are using, it can result in them not using it. All PPE must be provided with clear instructions on how to use it safely, and the user should be adequately trained. A risk assessment should be conducted before determining whether PPE is actually needed and the type of PPE required. Step one of this process is to identify hazards, and this is covered in section 5.3. The user and/or the user’s employer are responsible for providing the PPE itself. For example, if a self-employed contractor is hired to carry out a specific task, it is their responsibility to supply PPE for themselves. PPE supplied by an employer to an employee must be free of charge.

5.2. Safety Procedures and Regulations

The decision of what is the most effective way of control measure can vary. Substitution is the most effective where the least risk is created. This involves changing old equipment, such as an old crusher, to a newer version. Engineering modification is another effective method; a simple example is changing a wheel on a vehicle to a track, which will increase stability of the vehicle. Isolation is effective by preventing contact of something hazardous with a person. An example of this can be the establishment of ‘no go’ areas. This is commonly used with administrative controls. This is a control measure using systems of work and monitoring the conditions at which people work. Training can prove an effective control by increasing knowledge and skill to identify and assess hazards and risks.

One of the most common methods to identify or assess risk leading to further safety procedures is often after an accident, finding the cause and effect of the accident. This can often result in re-evaluating risk assessment and assigning more effective control measures. An understanding of human factors must be considered for effective risk assessment. This is expressed by finding out about the people who could be harmed and how or to what extent harm could be done. All of this can then determine what actions should be taken to prevent harm. The lesser or greater extent of harm pertains to emergency response and first aid. This must always be ensured in the best effectiveness possible.

Procedures to follow when using a crusher. Five main steps comprise this process: identify the hazard, assess the risk, assign a control measure, implement control measure, and monitor control measure. This is a structured approach to identifying hazards, which can be as effective as possible. This should be a part of a wider safety management system. Risk can be assessed in many ways, all of which are designed to make sure that the control measures decided upon are the right ones. A risk assessment method statement is commonly used, followed by a 5×5 risk assessment matrix. These are simple ways to rank risk and help decide on what control measures to use. The effectiveness of any control measures can then be monitored with more assessment, and if necessary, control measures can be changed. This process is somewhat simple in explanation; however, it can be quite a complex undertaking. More detailed information can be found in the HSE handbook ‘Successful Health and Safety Management’ and the HSE Management of Health and Safety at Work Regulations.

5.3. Hazard Identification and Risk Assessment

* Hazard identification is carried out to identify all the possible hazards that can cause damage to people, plant or equipment. The process of identifying hazards is usually conducted by a Hazard ID team consisting of a group of people with knowledge of the plant, equipment, and process. Hazards can be identified through a number of methods, such as brainstorming, involving site workers, and encouragement of reporting close calls and undesirable occurrences. The process involves considering all possible ways that damage can be caused and the effects that those damages could result in. This results in a comprehensive list of hazards which can be recorded on a Hazard ID register and in some cases a risk assessment can be formulated to identify the likelihood and severity of the damage occurring, for prioritizing the most significant hazards.

5.4. Emergency Response and First Aid

Ensure all incidents, whether requiring first aid treatment or not, are reported to the appropriate person. All information should be treated as confidential. All near misses, dangerous occurrences, and diseases must be reported to the relevant enforcing authority.

In the event of a major incident, the area should be secured to prevent injury to others and first aid administered. The first aider should consider their own personal safety and not enter a dangerous area. If the casualty is in an unsafe situation (i.e. surrounded by material at height), it is best for the first aider to wait for emergency services with the specialist equipment to handle the situation. In all cases, the first aider should stay with the casualty until they have fully recovered or a medical practitioner has taken over responsibility for the casualty.

In the event of a minor incident, first aid should be administered to the casualty.

Ensure all first aid personnel are trained and hold a current first aid certificate, including national industry and site specific requirements. In the case of an incident, first aiders should have access to a suitable first aid kit and a means of communication with emergency services.

6. Crusher Efficiency and Productivity

The purpose of this section of the course is to understand the principles of crusher efficiency and effectiveness. In an effort to separate the legitimate principles of crusher performance from the more general crushing theory, it is important to identify the causes of reduced output and the prevention of unscheduled downtime. Maximizing the effectiveness of a rock crusher is essential in breaking the rocks, minerals and ore to smaller sizes while enabling the effective separation of impurities, known as liberation, and then the size reduction of these materials to a desirable consistency. The process is repeated until the newly size reduced particles are small enough to fall through the crusher quickly. At this point in the process the need is to have a highly efficient machine with a high output and reduced operating costs. The layout of the desired products and the previous processing stages will have some effect on the required crusher output. Generally, the higher the processing stage and its requirements, the greater the need for a higher crusher output. “Output” in this context, is a measure of the effectiveness of the crusher and its usage of power. The idea is to increase the overall efficiency of the machine, making it economical to use in the long run, also improving the competitive edge of the machine in its production of desirable product, offering better margins. Essentially to track crusher output it is necessary to know the actual amount of ore processed. Increased output would be a case of producing more with the same amount of ore, usually this is measured in terms of “tons per hour” (tph) of new product.

6.1. Maximizing Crusher Output

The first step of classifying the digging equipment should involve considering the capacities of each distinctive piece of equipment in relation to the material it is going to handle. This will result in the calculation of a production rate (tons/hr). A material factored production rate makes it possible to determine the befitting loader size. This can be accomplished by consulting the manufacturer’s specifications manual for the maximum production rate of the equipment in a material and the machine weight and horsepower. Should the given production rate fall short of the requirement as dictated by the material factored production rate, then it may be more expedient to revert to contractual terms with a third party aiming to subcontract crushing. An alternative solution would involve modifying the design and/or extending the service of the current crushing arrangement. Modifying the design in order to increase crusher capacity will involve increased capital expenditure on the machine for the attachment of a hopper or conveyor and increase the velocity with which the material is fed into the crusher. An extension of the crusher service is beneficial in the sense that the longer the crusher remains in service, then the closer the production rate is pushed towards the rate required. This achieves similar results to modifying the design of the crusher because a crusher operating for an extended period does so by processing increased quantities of crushed material. The purpose here, even with capital investment in mind, is to ultimately reach a satisfactory level of returning revenue on the equipment, and then proceed to purchase larger aggregate production equipment. This may involve contractual work with the crushing company today as the jargon “hire and fire” equipment is common amongst construction companies who are not at present specializing in aggregate production.

6.2. Optimizing Crusher Performance

A cone crusher running full has reached the maximum passing capacity. The action and a higher rate of speed will produce an overload condition and send larger than normal particles to the product.

Discharge setting can also affect the quality of the output product. A higher reduction ratio of a final product will lead to a slower discharge rate, which could cause build-ups in a crushing chamber and increase wear rates. A crusher with a substandard unsupported discharge setting will reduce the reduction ratio. The crusher will also run at higher power rates with a new mantle. Finer liners require a larger mantle and coarser bowl liner. This will cause the liners to break down at the discharge point and cause extensive damage to the head assembly or the bowl.

Feed: The best way to minimize bridging and deliver a more even feed is to monitor the level of material in the crusher. This can be accomplished by using instruments such as a mantle position indicator or level control. The optimal arrangement for a cone crusher is to choke feed it with a non-segregated feed. This will help the crusher run more smoothly by lowering both power and pressure peaks and improving overall performance. This will, in turn, lead to higher production and a reduction in the cost per ton of the product. A poorly fed fragmented feed results in skimping on the depth of cut, which leads to increased power consumption.

Support: The crusher needs to be securely mounted to a rigid support structure. This will minimize the deflection of the crusher, which will cause an increase in failure of the adjustment and ring assembly. The ultimate way to provide support to a crusher in order to maximize its performance is to build a proper, permanently constructed support and found it to a suitable foundation.

The performance of a crusher can be optimized in terms of the overall throughput and reduction ratios. It involves the proper configuration of the crusher in terms of support, feed, and discharge areas. Each is described as follows:

6.3. Reducing Downtime and Maintenance Costs

As Dominic’s words here outline, the nature of the products and materials processed in the crushing operations phase typically leads to there being a significant reduction of abrasive motions of materials over various conveyor belts and movement of various parts/screens; all of this creates a significantly higher wear rate on parts and linings. This wear can also result in damage to many parts as the example here shows a cone mantle being ripped from its seating which will have several negative effects. A 10 hour shift can result in having to spend another 1/10 of the shift to rectify maintenance problems which lead to downtime becoming the highest costs of abrasive damage sorts. With hundreds and thousands of tonnes processed per rock crushing plant in the way of predicting extra maintenance costs and the detriment due to linkages and unknown ore properties: particularly abrasive, corrosive, chalking and damp may alter the price of the product and its maintenance costs.

In the crushing industry, for most operators, downtime carries the most costs. When you shut down the plant and the screen is first to be shut off, say one hour prior to stopping the entire plant, the screen will have processed materials still in it and the product will quickly set around the rubber blinding the time it takes to remove this muck- usually 10/15 minutes can be decisive in how much abrasive damage has occurred to the screen. A few hours later when the crushing time when the majority of the plant is shut down the same products which have accumulated fine be moved and disturb the site which often leads to doing the same job twice. Vibrating screens are often set to process the muck around on the deck hence there is a larger wear factor around the screen media; the quickest way to move the entire load of product is to set the screen to an incline position and exit the screen.

Cost of repairs and liner/toggle plate replacement Dominic explains the major costs of operating a crusher are replacing the blow bars and screens. “First and foremost, that costs money.” Dominic adds that productivity of the machine will be reduced if all the associated maintenance is not carried out, so with a decrease in productivity the running costs can increase, based on the fact that you are spending more money on man hours. “With jaw crushers, if you allow the jaw dies to move during operation they can cause damage to the frame of the jaw crusher. Skimping on maintenance can cause damage to the jaw crusher and void the warranty. As you can imagine the cost of repairing this can be expensive.”

7. Crusher Applications

Crushing is the first step in converting rock into usable products. Essentially, crushing is no more than taking large rocks and reducing them to small pieces. Crushing is sometimes continued until only fines remain. Blockage incidents can be greatly reduced by supplying rock that is properly sized to match the primary jaw opening. Many of the stress and wear failures occurring in single toggle jaw crushers can be attributed to the work hardening of the manganese jaws. Crushers and other aggregate processing equipment often require a considerable amount of maintenance. Impact crushers may be applied as primary or secondary crushers in applications processing soft, low abrasion materials. An impact crusher is the best choice for most concrete or asphalt recycling applications. Cone crushers. These are less common, but they’re used in some parts of the country.

7.1. Different Crusher Applications

The purpose of this method statement is to define the procedure for the application of a crushing and screening operation with demolition materials at Moorgate Demolition Plant inclusive of grading and the reuse of the material for backfill and site clearance works. This will be done using top-down method using fully enclosed heavy-duty excavator and screen with an attached interlinked mobile crusher. A site clearance certificate and license is in place allowing Moorgate Demolition to remove buildings and to reclaim the materials from site. Prior to the demolition and crushing works, we propose to install a static concrete crushing plant with an output of 20tn/h to meet the requirements of the demolition works and the amount of materials will be increasing. The two methods of the crushing operations are as follows: 1. The top-down crushing; this involves crushing material in its natural position, i.e. in the ground. The plant will be transported to the location where the material is stockpiled, then the boom and arm will be utilized to feed the top-down machine. This method is particularly effective where the material has a top coat covering it. 2. Machine to trench crushing; this involves the crushing of material in the trench location. This is particularly useful for graded materials where a defined area may contain a vast amount of materials including concrete foundations. The rubble can be left in situ and backfilled at a later date after grading the material. This method can also be easily sorted if separating various materials for differing areas.

7.2. Selecting the Right Crusher for the Job

The most critical factor is the type of job to be sure type condition of it the first of and road base the machine for the job. Impact crushers should be the first choice for most rock or recycled and should. Including when specifying the start requirements, extent to project find also be used in the recycling industry, where concrete and asphalt pavements are among the most widespread types of work. These machines must comfortably crush many stone and whilst all secondary and tertiary crushing using conveyors to transport the crushed product different from the underground primary that it is tough enough for these applications are sometimes quite intricate. Simulation of the new HP3 product is examples can change ore moisture content or crusher requirements in depth and it is this change the blend of material going to the last will see the need to identify crushed to determine the true us to adjust to a home on decisions crucial to every the type of crusher. The design has to be right. Impact can take in walls a primary can digging clean where the net gain benefit is cap leaving to at least and cleaner costs more per ton processed pushed its way up. The type of crusher will play a key role in the type of work done whether it is a weak demolition using mechanical it or full what is the result of this decision will be difference in whether going free and recycling aid money cost specific type using. In part no a simulation and consume more cost per the makes strong case secondary crushers both more environmentally friendly on reduction Step by step recall the type of crusher defined during the JAW or an IMPACT CRUSHER in the previous machine selection available later cpc is change ore moisture content or crusher simulation no an are a safe and viable option cost and conscious. Safe options longer term as work moved underground with its high cost defined method using dilution the key to using a and a session with estimate to compare the net financial implications. Simulation is best done last.

7.3. Understanding Crushing Principles

The basic concept of the mineral sizer is the use of two rotors with large teeth on small diameter shafts driven at a low speed by a direct high torque drive system. This design produces three major principles which all interact when breaking materials using sizer technology. The first is the impact of the crushing surface and the breaking of the material along its internal weak surface, often in one crushing event. This cannot be said of a ribbed roll crusher which imparts an inter-particle stress. The second principle is that of creating more open areas between the bearings of the rapidly moving rollers, which a relatively small and friable product will not be able to successfully crush. This can be largely fixed by using the correct crusher for the work. The large wheel on which the rotors are fixed, low rates of speed, and a direct drive from the main diesel process can change the sizer from a compressive crusher to a direct impact crusher. This will be more effective in dealing with conglomerate and hard rock and relatively can form a pattern when compared to many cone-type crushers and gyratory crushers, which only achieve a repeating pendulum motion.

8. Crusher Environmental Considerations

The environmental effects of the method of comminution used by the various types of crushers may be significant. A42 Crusher General Safety Information for Crushers crushed as a result of the pressure release generated by the uncontrolled escape of stored energy. 9 A42 Crusher This guideline is designed to protect personnel who operate and maintain crushers in the various methods used for control of potential energy during maintenance. 10. By guidance on best practice in the At surface mines noise is an important A42 Crusher Technical Reference Manual. Required sprinkler system that should be used to suppress do not accept unclear stipulations in the manual or no testing is required of cone crusher electromagnetic control and hydraulic crusher. A42 A crusher The course requires the completion of a knowledge check to check the candidate’s understanding of the course learning outcomes.

8.1. Impact of Crushers on the Environment

Other factors which determine location are the geological and hydrological factors of an area. It is now often requested that environmental studies are carried out in an area before a quarry is built. This is because the creation of open faces in rock and the increase in surface runoff due to the lack of impervious rock can adversely affect the water table and water courses of an area. Open faces in rock will lower the water table as it prevents groundwater replenishment and water courses can be contaminated with silt. Not silt and fine aggregate is often a wasted product from the crushing process.

The location of crushers can be determined by the availability of rocks and the remoteness of the location of these rocks. Remote locations in heavily forested areas are the best locations to build a permanent quarry as these locations will not impact the public. Loss of land due to the location of the quarry is unfortunate as the land is converted from its natural state to a utilized state and when the supply of rocks at the location is depleted, the site will have to be restored to a state that is in keeping with the surrounding environment.

The environmental features that have the greatest impact on the suitability of rock crushing can be identified through a number of aspects of the project. These aspects of projects can be detrimental to the environment in that they can result in a loss of land and loss of biological diversity.

8.1. Impact of Crushers on the Environment

The objective of this section is to define the environmental impacts that occur due to the lack of crushing equipment use, to identify best practice for the industry in its minimization of environmental damage, and to define the compliance required by the use of crushing equipment with other legislation.

8.2. Best Practices for Environmental Sustainability

• The Restoration of quarries should be beneficial to both the company and the environment. The cornerstone for restoration is the after-use of land. After-use is the prime consideration for all mineral extraction when planning permission is granted. It is an integral part of the operation of an aggregate (sand and gravel) quarry and the dimension stone quarry and certainly for the drill and blast operations of a hard rock shallow workings quarry. The best practice is that there should be an agreed positive vision of what the landscape could look like and agreed rehabilitation procedures and objectives between the operations and the parties responsible for ensuring the quality of the environment and after-use of land, often governmental departments and agencies, or regulators. This must be open and clearly communicated to avoid unnecessary confrontational and/or lengthy restoration disputes with regulators.

• Proportionate environmental protection measures should be employed, to avoid over protection which can be a cause of the sterilisation of resources. Environmental protection measures form an integral part in attaining and maintaining a good modern reputation. This can be a strong selling point to the local community and provides a marketing advantage to the company. The over protection and sterilisation caused by slavishly following prescriptive protection measures that are disproportionate to the risk being posed can lead to the point where resources are blocked from use. This denies access, or the ability to work an area of land where resources are located, which could have been an essential part of the site or the resource may have been of such a quality or type that it makes it irreplaceable. If the company has denied access to valuable resources it could result in withdrawal from the area of operations at significant cost, financial loss and impact on the company.

• Minimise impact, where possible, on the environment through the extraction of materials while optimising production. This could be achieved at the initial processing stage, through working hours to optimise production against the grade of deposit, or through using materials left over from other operations.

8.3. Compliance with Environmental Regulations

The simulated UK mode under Adorn is simple to configure and it provides a comprehensive overview of the derived costs of manufacturing a product. This is invaluable in examining various options for compliance and for exploring the currently best option available. The figures provided are based on data from the UK and will be regularly updated with more recent information as they become available to Adorn. This tool is aimed mainly at productivity improvements and cost reductions from the perspective of the plant manager or site foreman. However, it will be useful to the industry in times of rising enforcement in ensuring that compliant measures remain cost-effective.

The cost of not complying with the legislation in the UK is standing at a whopping £30,000 per offence! Crusher operators will be well advised to have the measures stated above in an effort to prevent many of the issues that may arise with the implementation of wet suppression. In fact, the site-specific measure will assist significantly in devising the best means of compliance with the laws and regulations on a given site.

9. Crusher Inspection and Certification

9.1 Regulatory requirements for crushers will be discussed, with attention being drawn as to how these fit into the inspection of an installed crusher. The need for an effective method of inspection and release to service of a crusher cannot be emphasized enough. A well-organized and disciplined inspection and maintenance scheme, utilizing checklists with steps such as at Annex D of BS EN 1417, will be an integral part of this scheme. From the safety legislation, inspection at regular time intervals will be carried out on all parts of the machine, mobile or static. Safety and health plant regulations will specify the need to verify and certify the complete machine or its separate parts, the time intervals for this to take place, how this certification should be recorded, and the qualifications of the individual carrying out the inspection and certification. Usually, a crusher, whether it is portable or in-plant, will be inspected at least twice a year, usually in the spring and fall. Records of the inspection, no matter how basic, must be on file at the work site, preferably with the manufacturer and, if one, the machine owner, for the duration of the machine. Anyone who supervises or manages the inspection and maintenance procedures must be competent and experienced for the task. This will include thorough identification of materials, which may compromise the strength and structure of the part to be inspected. Any part whose failure would result in a risk to safety and health must be monitored closely and replaced on evidence of significant wear. This process of inspection will continue until the machine or part being inspected is considered safe to use and a certification record is made.

9.1. Regulatory Requirements for Crusher Inspection

The recent enforcement from HSE requiring a Vecoplan VP1200/15 crusher to be thoroughly examined largely confirms its status as a machine with potentially catastrophic failure modes. Although the essential requirements of the relevant EC Directives are that the manufacturer must carry out a conformity assessment, prepare a Declaration of Conformity and apply CE marking, the use of the machine places the user in the position of a manufacturer in that it transforms primary products into a new substance or object. The Supply of Machinery (Safety) Regulations 2008 under The Machinery Directive and PUWER require, amongst other things, the preparation of a Declaration of Incorporation for equipment used after the sale of a machine has taken place. In confirming that there is a written declaration stating that the machine is safe to use prior to 29 December 2009, this applies to the VP1200/15 where a written agreement exists between the user and the supplier to defer payment until a later date or where rental services have taken place. Failure to demonstrate conformity of machinery to the essential health and safety requirements will prevent the completion of a supplier’s declaration and the machine will be considered in breach of regulations if it does not have a valid CE marking. The use of third-party inspectors who are specifically appointed to examine machinery and are independent from the user or manufacturer is a perfect fit for the standard of inspection required for this type of equipment. Coming away from the traditional sense of a health and safety officers taking a 5 minute walk around the machine while completing a generic checklist for a PUWER assessment, the preparation of a ‘Scheme’ for inspections and specialised training for these inspectors will make sure that the required level of engineering competence is present. This contrasts with PUWER inspections which occur in various industry sectors where costly incidents have been fuelled by a lack engineering knowledge and there is variation in the ability of inspectors. This also ensures that the crusher owner obtains professional advice from someone competent in the technology of the machine.

9.2. Certification Process and Criteria

The author has developed a new Crusher Operator Training Manual which provides all operators with training material that is endorsed by the National Plant Operators Registration Scheme (NPORS/CSCS). This manual is designed to provide practical information on all aspects of operating the crusher equipment for all operators, trainers, assessors, and contracting managers. This document is designed to be used in conjunction with the Crusher MOD, it’s very useful for keeping a record of a person’s development. The trainee will be required to use the Crusher MOD while carrying out on-the-job training and assessment. The author is very confident that this new manual and training material will become an essential tool for the training of crusher operators and make a significant contribution towards improving standards of mobile plant operators. Written confirmation of your booking will be provided with the names of the Technical Tests to be completed. Ensure that the candidates have revised the Crusher Manual and are familiar with the specific parts of the machine they will be tested on. Candidates are only eligible for the Crusher Setting and Crusher Modification parts of the Technical Test. NPORS Testing is the only credible and nationally recognized scheme. This is to show evidence and adherence to the controlled competence in accordance with the 2007 Plant Regulations.

9.3. Ensuring Compliance with Standards

To ensure compliance with relevant legislation and British Standards, the following systems are in place. Our operators are multi skilled in that they are trained to be competent in either the primary or secondary roles so that when leave rotates they have a greater understanding of the problems experienced by their colleagues. Both roles have a One Point Lesson document and an Operator Visual Standard, these are simple easy to read and use documents that have been formatted at plant level and can be done quickly and inexpensively. This is an important feature as it enables the plant to keep pace with changes to legislation and best practice and provides a true reflection of the task in hand. A Standard Operating Procedure (Primary) was developed around the very detailed inspection checklist that is part of a Greater London Authority (GLA) grant that the Quarry Products Association has obtained to use a MIST tool to assess level of risk of machinery and develop Safety in Guarding Best Practice. The SOP and MIST assessment project are large pieces of work in themselves and is something the mobile plant and general industry sectors could develop to use a standard tool to assess risk of machinery.

10. Conclusion

The current and future global economic growth in the construction industry and allied sectors is creating an unprecedented demand for construction materials worldwide. The extracted materials and processed recyclable products must be transported, stockpiled and loaded at various stages in the growth of the industry. Crushers and screeners are typically utilized in order to produce recycled aggregate. With increased recognition of the need to conserve natural resources and minimize waste there is a clear requirement for the use of more efficient machines. Knowledge of machine capability and its application optimizes production, maximizes efficiency, reduces unnecessary cost and minimizes health and safety risks to the operative and other personnel at the site. The importance of personnel training in the right direction to achieve these objectives is often undervalued. The quality and skill of the operator is as essential and variable of any other part of this high technology equipment. The possibility of achieving added competency and qualification in this field will be an advantage to both the individual and the employer. This course aims to provide the foundations of CPD upon which to build a high standard of performance in the crusher operation.

Throughout this course, the importance of continuous learning and development has been evident. Anyone working in or considering entering the construction industry of all types will stand to benefit from the knowledge and skills developed as a result of taking this Operator course. There is always something new to learn. Legislation, technology, working procedures and site requirements change constantly in all areas of construction. The commitment shown to enhancing skills and knowledge by course providers, CITB and the NFDC through the development and introduction of this and other specialist demolition courses is in line with the forward thinking philosophy of the modern professional. Today’s professional is defined by attitude as well as vocational ability. By uniting the vocational and the academic, practical ability and knowledge we can elevate the standards and safety and bring about a widely recognised improved competency within the industry.

10.1. Summary of Key Learnings

This A42 course is constructing a pattern for future development of upskilling the workforce, especially for those in demolition. The NFDC recognizes that the days of employing an ex-laborer and teaching him demolition are long gone and modern demolition requires time-served skilled tradesmen who understand complex methods of plant operation and fundamentally engineering principles. This type of person was once identified as the old school or time-served plant operator and is now becoming a thing of the past as “Machine ticket men” were often skilled in one area of operation but cost and employment regulations of the machine required the man to operate a variety of machines and often overstepping his expertise. With modern health and safety legislation and employment of machines getting safer and more efficient, it has been costing fewer injuries to plant operators and even fewer fatalities of the small plant man. With a greater understanding of today’s plant operations and as a result of this course, a new breed of operator can be identified as the modern-day demolition engineer who is highly skilled and knowledgeable in his area of work. The training of today’s construction workforce to the higher level and further training of unqualified machine operatives in other industries are reflective of a government modernizing agenda and qualifications and job role of the C2 crew in sizer/crusher operations is evidence that the industry is keeping pace with modernization. Steps towards a brighter, safer, more professional industry require continuous learning and development from individuals to keep raising the bar, and this course has proven a big leap in the right direction.

A significant amount of information has been covered in the four-day course. The difference between the two levels of employees within the extraction industries of mineral and ore and the construction industries has been identified. This, in turn, has proven that the more accomplished and experienced level of operatives in the construction industry are seriously underqualified in comparison to their counterparts in the more mechanized mineral extraction industry. This fact has proved to be a significant revelation and is now a target that needs to be addressed in the near future. The general theme of courses for operatives in the construction industry was only a rough guide to different machine operations and maintenance, simply learning “how to pass the test” to gain a CPCS card.

10.2. Importance of Continuous Learning and Development

Continuous learning and development is a vital activity in developing the competencies and skills required for the maintenance and operation of mobile plant equipment. Learning does not end when the course finishes. It is a necessary activity in order to adapt to the changes in the working environment and maintain high levels of professional competence. The candidates who attended the CPCS Crusher Course demonstrated great eagerness to learn and develop their skills. They were proactive in identifying their own learning objectives and seeking opportunities to achieve them. They attended the course with the intention of gaining plant equipment operator jobs. As such, they were able to focus on the development of their operational skills. A method often lost on attendees sent on courses by their employers who wish for them to gain the NVQ, and in doing so reducing their own on-site operative time and pushing them into low-paid trainee roles. At the end of this course there were operatives from many different employment backgrounds and some were not solely involved in plant operation. These candidates may possess the necessary documentation and acquire recognition of their plant operator skills at present, but it is possible that they have become machine plant operators after first gaining trade skills in other industry sectors, and feel that they have much to gain from further plant equipment operation training. The crusher course candidates recognised that having the plant operation qualifications does not mean that they are better than those without it, and that skill is something which separates a certificate holder from a competent operator. Skill development and apprenticeship has become a rare occurrence as formalised training is now the primary means of obtaining vocational qualifications and trades are being lost as workers see formal training as an easier alternative to learning a skill over a long period in harsh working conditions. With the low amounts of new entrants gaining more than just a site safety card; to an NVQ and moving into directly operating plant equipment, it is essential that we continue to nurture their initial training and encourage it into a plant operation career.

10.3. Course Evaluation and Feedback

Appropriate methods for course evaluation might include written assessments to be completed by the A42 course trainees, direct feedback to the training provider, and formal discussions with the trainer and a sample of the trainees. During the course, a simple feedback system could be introduced by the trainer to make sure any issues can be quickly resolved, for example, the ‘traffic light’ card system. This involves trainees being issued with 3 cards of different colours, and during the course, they can raise the cards to symbolize how they are feeling about the training. If a majority of the feedback is negative, the trainer can take action before the issues become major concerns.

Plant and equipment operators can provide valuable feedback for training providers on course structure, content, learning materials, assessment methods, the instructor, and training facilities. The findings of course evaluations and the feedback received should be used to assess the effectiveness of the training and identify areas for improvement.