Efficiency in the operation is assisted by providing a good working environment and by arranging the plant to facilitate the operational and maintenance tasks. Good lighting and heating are important and sufficient ventilation is necessary to protect against dust and fumes. Proper covering and venting of some leaching tanks is important to eliminate a frequent source of toxic fumes in the plant building. Some gases and mists are also quite corrosive and may cause damage to the plant structure and to other equipment as well as causing a poor plant appearance if not vented outside. Safety is a primary consideration in the plant design with floors, walkways and start built to prevent slippage and with handrails provided in dangerous zones.
Transfer points and other points which might splash or overflow are covered or otherwise protected. Open grating-type floors are not satisfactory in some areas where spills or falling objects might be hazardous to equipment or personnel below. Other normal safety measures such as belts and shaft guards, avoidance of low piping across walkways, fire control equipment, etc., are factors to be considered in the design. For example, fire control is particularly important in the area of activated carbon stripping or bullion smelting in view of the common use of alcohol, fuel oil and other inflammable materials in these operations. Construction materials which might soak up inflammable solvents should be avoided and good floor drainage provided. Automatic, foam type fire extinguishers are increasing use. In the analytical laboratories special precautions are taken to vent hoods so that acid fumes do not come in contact with organic materials and form highly sensitive explosive compounds. Serious explosions have occurred in the past sue to use of organic caulking materials in hood ventilation systems.
The plant and crushing facilities are designed to reclaim losses and spillage and for ease of washing with hoses, with the floor sloped at least 5-8 mm per meter and with sumps provided to handle the drainage. Sump pumps provide for transfer of valuable slurries and solutions to the circuit and wastes to disposal with the tailings. Maintenance is materially aided in the more modern gold plants by providing for easy access to the equipment with sufficient aisle space and room to permit repair and if necessary, for removal and replacement. Planning allowance is also made for possible later changes and expansions. Overhead cranes are employed to handle heavy equipment and for other purposes and are built to traverse as much area as possible.
The supply of reagents to the point of use deserves special consideration in design since this service can be time consuming and therefore costly. In some gold operations, it is found desirable to prepare reagent solutions at a central location near to the main storage area and to then pump these solutions through closed pipe loops to the point of use, with a return to storage. For example, this is frequently done with flocculant solutions serving a series of thickeners. A central aisle space serving various unit operations on opposite sides of the mill is found to be convenient to provide access for both supply and maintenance.
Reagent preparation system