World Without Pumps – Mining
These anecdotes are the result of a campaign launched to raise awareness of the importance of pumps and the pump industry in all of our daily lives.
Pumps Are at the Heart of Mining
Nearly four decades ago, in the 1953 film Gentlemen Prefer Blondes, actress Marilyn Monroe famously sang the song, “Diamonds Are a Girl’s Best Friends.” Today, even while playing their sport, many male professional athletes don multiple-carat diamond studs on one or both of ears—non-athletes wear diamond studs too.
We’ve sure come a long way in 40 years in how diamonds (for women and for men) are perceived in society. But the fact about diamonds that goes mostly unnoticed is that diamonds would be much more difficult to attain without the use of pumps. Slurry pumps are used for alluvial and marine mining operations. The diamonds get washed down into rivers, and in some cases, out to sea, and pumps are used to mine these deposits, which are sometimes at depths of several hundred meters. Whether diamond ore is minded wet or dry, it may be processed wet using pumps, screens and cyclones.
When extracting precious diamonds, gold or silver, or other useful metals like copper, nickel, and zinc—or even coal—everything begins with mining, and as noted with diamonds a large percentage of mining operations depend on pumps to extract and convey materials, dewater the mine, and for processing and separating of the mined ore.
Pumps provide water for extraction, cleaning, processing, and other uses. Pumps are also used in mobile mining equipment to power the hydraulic cylinders and motors that perform the functions needed to move and process material throughout the operations.
There are two major types of mining: surface mining and subsurface (or underground) mining. In surface mining, surface vegetation, dirt and sometimes even bedrock are removed to reach buried ore deposits. Major techniques used are open-pit mining, where minerals are recovered from a very large open pit, and strip mining, which uses a more targeted removal of surface layers to reach the ore deposits. Subsurface mining requires digging of tunnels and shafts to reach deeply buried ore.
While the processes used to extract, treat, and further process each mineral may differ, pumps supply the flow and pressure needed for specific applications where water is used for separating, cleaning, washing, cooling, dust control and more. Centrifugal pumps of various configurations are used most often.
The following are some typical applications where pumps are used in mining operations:
Mineral extraction – In some processes, such as hydraulic or solution mining, water is used to extract the minerals. Hydraulic mining uses jets of high-pressure water to cut through waste rock or sediments and get to the ore body. It is used frequently in underground coal mining to break up the coal seam and wash away sediments. This requires pumps that can produce the necessary high pressures. Solution mining is the method commonly used for mining uranium and other soluble minerals, like potash. They are leached in place, usually with boreholes drilled to reach the mineral deposit and, of course, pumps are required to bring the solution through the boreholes to the surface.
Conveying ore and wastes – Some ores, such as coal, are easily pumped through pipelines in a slurry or suspension of water, usually by a centrifugal pump designed with heavy-duty components and features. The same thing applies to waste materials produced after the ore is removed, as pumps are used to transport hazardous waste from mining sites. Other pump designs such as rotary lobe, twin screw or diaphragm types also may be used, depending on the application.
Dewatering – Pumps are needed to remove the water used in processing, as well as the water that occurs naturally because of rain or groundwater. Typically, an underground mine will have to deal with more inflow of groundwater than an open-pit mine. For open-pit mines, dewatering pumps help manage rainwater, improve seepage water management, and lower the water table to prevent ground-water influx. In underground mines, pumps keep water out of sumps, optimize main drainage, and lift water out of shafts. Centrifugal pumps, often submersible, typically are used in these applications.
Dewatering brings special benefits when recovering diamonds, which are among the most expensive items in the world by volume but also very difficult to extract. In one case, columns of diamonds were located submerged under a dike in Canada’s Northern Territories. Dike walls were built around them, and self-priming centrifugal pumps removed 2.5 billion gallons of water in seven weeks to allow the diamonds to be extracted.
Cooling – High-temperature processing is often the final step in mineral processing after the ore has been refined through size reduction, sorting, concentration, and dewatering. In these cases, a water bath or spray may be used to cool, by either heat transfer or evaporation. Pumps supply the required high volume of water, which is often pumped away to be recycled and prevent waste.
Washing and cleaning equipment – Handling and processing minerals from the earth creates a large amount of dust and dirt. Washing usually requires a high-pressure centrifugal pump to dislodge the dirt and grit, especially from critical or hard-to-reach equipment areas. While water is used to clean the equipment and prolong its life, it also is sprayed to suppress dust during many operations. Dust suppression creates a less hostile work environment and protects machinery and equipment. It also protects workers who could experience potentially life-threatening medical issues, including lung irritation, asthma, and other diseases if exposed to fine dust particles. Plunger, piston, or diaphragm pumps are used for most misting applications.
Rock and Gravel Quarries – Although not usually thought of as mining, the removal of rock, sand and gravel from quarries is much like other surface mining operations, with similar needs for water. While rock quarrying and crushing uses water mainly for dust control and cleaning, sand and gravel operations have greater needs. These quarries often have to be pumped to remove water. After being conveyed to a processing plant, the materials require washing to remove unwanted clay and to separate sand from gravel. In all cases, pumps provide the necessary flow and pressure.
Mining Equipment – Mobile equipment such as excavators, loaders, drill rigs and large mine-haul dump trucks incorporate pumps to move the fluids that activate their hydraulic cylinders and drive their hydraulic motors. In these applications, they provide power-dense solutions to handle tough or heavy materials. Depending on the application, a positive displacement, centrifugal piston or gear pump may be used.
So, whether you pine for the days of Marilyn Monroe, or prefer watching your favorite millionaire star athlete, remember that pumps are a diamond’s best friend.
Check out the other World Without Pumps!