Introduction
This part of the publication is concerned with processing the mineral.
Processing
Processing is essentially sizing the material by means of crushing, milling, screening, washing, primary sizing within the quarry, sawing and splitting.
Processing the mineral
Crushing
The hazards are blockages, tramp metal, high noise and dust levels and vibration. At risk are the machine operators, maintenance and cleaning staff.
The preventative measures include the use of hydraulic hammers to break up blockages and providing noise insulated control cabins which also have mechanical ventilation systems designed to remove any harmful dust. The cabins should also be provided with vibration damping devices to isolate them from any harmful vibration.
Careful attention must be paid to guarding dangerous parts of the equipment and handling heavy components during maintenance work.
This part of the publication is concerned with processing the mineral.
Processing
Processing is essentially sizing the material by means of crushing, milling, screening, washing, primary sizing within the quarry, sawing and splitting.
Processing the mineral
Crushing
The hazards are blockages, tramp metal, high noise and dust levels and vibration. At risk are the machine operators, maintenance and cleaning staff.
The preventative measures include the use of hydraulic hammers to break up blockages and providing noise insulated control cabins which also have mechanical ventilation systems designed to remove any harmful dust. The cabins should also be provided with vibration damping devices to isolate them from any harmful vibration.
Careful attention must be paid to guarding dangerous parts of the equipment and handling heavy components during maintenance work.
DIAGRAM 17
During maintenance work persons may have to enter some parts of the machinery which are confined spaces and need good isolation procedures to eliminate risks from oxygen deficiency, fires and explosion risks and engulfment by material.
Milling
The hazards are noise, dust, entrapment, confined spaces and chemical additives.
The risks are confined normally to operators and maintenance personnel.
Noise and dust hazards can be reduced by the provision of control cabins insulated to protect the operator from noise in excess of control levels and fitted with an air filtration system that protects the operator from inhaling harmful dust. Suitable personal protective equipment will need to be provided for maintenance personnel.
Dangers from the use of chemical additives can be reduced by the adoption of normal preventative measures such as substitution, implementing controls such as automatic piped feeds, personal protection and ventilation.
Screening
The main hazards are dust, noise and vibration, and falls from height during maintenance work.
The provision of a noise and dust insulated air conditioned cabin is sufficient during normal operations.
During maintenance work care must be taken to ensure that adequate temporary working platforms are provided as the screen system is dismantled to prevent person's falling through the resultant opening. It may also be necessary to provide people with suitable protective equipment to safeguard them against the inhalation of residual dust.
Sawing
This is normally limited to the processing of free stone such as slate, marble and granite.
The main hazards are noise and dust, particularly at circular saw machines, entrapment and manual handling.
The precautions to reduce the risk of injury include noise and dust insulated and air conditioned cabins, personal protection such as ear defenders, water sprays to suppress dust and training operators and their assistants to recognise the dangers when approaching reciprocating equipment.
The dangers associated with manual handling should be identified so that handling aids can be provided and the necessary training given to educate operators in the correct means of handling heavy, often irregular shaped material.
Splitting
The hazards are dust, noise and manual handling.
Those at risk are essentially the operators.
Preventative measures for dust is the provision of local exhaust ventilation preferably of the high velocity low volume type and dust respirators.
Noise prevention is limited to the provision of suitable ear defenders.
Manual handling difficulties must be identified, when possible suitable mechanical aids provided and good training for operators in the techniques of lifting and estimating loads and difficulty of lifting.
