A pump is a mechanical device used for transferring fluid from one point to another. There are several different varieties of pumps that are found in the marketplace, but the most common in use are the centrifugal pump and the piston pump. The most common pump in use now is the centrifugal pump although in the past the more common variety of pump was operated with Pistons. The primary use for pumps in the mining industry is for the removal of groundwater that seeps into the mine from the surrounding strata.
|This is a Cornish piston pump used in the 19th century to pump water from a mine.|
In some mines the order is reduced to a powder that is mixed with a fluid allowing it to be pumped as a slurry. Other pumps are used to supply power too hydraulic units that are attached to various types of mining equipment.
No matter what its use; pumps require an external power supply that used to be supplied by steam, but is now replaced by diesel. In many cases the motive power for operating a pump is supplied by electricity this is especially true of the smaller pumps that have electric motor attached correctly to the shaft of the pump.
|A cutaway view of a centrifugal pump.|
Pumps are also used in various hydrometallurgical processes used to separate ore from gangue. This is illustrated by their use in flotation cells for separating sulfide minerals from the surrounding rock. In other cases pumps are used in the heap leach method of recovering gold with a solution of cyanide. In this case the pumps pressurize a cyanide solution forcing it out through nozzles where is allowed to seep down through the heap of crushed ore where it is collected in a sump at the bottom of the heap to be recirculated through the heap several times until the solution becomes pregnant with gold.
The pregnant solution is then drawn off, and the gold or other metal values are removed by reacting to solution with a powdered metal such as zinc to precipitate the gold that is then taken to a refinery for further processing.
In alluvial or placer mining centrifugal pumps are also used in several places notably in supplying water to sluice boxes or hide bankers. They are also used in the operation of a suction dredge for the removal of mineral laden sand and gravel from the bed of the stream. In larger gold dredges they are actually used to process the gold bearing sand and gravel.
|A gold dredge in operation in Nome, Alaska.|
As you can see there are many uses for pumps in the mining industry, and because man is an ingenious creature he keeps developing more!