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simplify waste storage and minimise the potential for contamination. Some mining requires more volatile practices, such as the use of explosives or extraction of dangerous and/or radioactive materials. When explosives are needed, mining companies must be able to comply with special conveyance conditions to ensure safe transport. When mining materials such as uranium, mining companies must be able to safely transport the concentrated powder obtained from leach solutions that’s known as yellow cake. All of these mining applications require proper pumping or conveyance methods to ensure safety and effi ciency.

Challenges and safety concerns Mining precious metals or hard minerals can place machines under extreme stress, increasing the chances for mechanical failure and the price of the raw material. T e sludges and slurries containing these materials are extremely abrasive and can destroy pumping systems in a matter of days. Although adding water can make it easier to pump, it also increases the eff ort required to thicken, concentrate and extract the substance later. T e effi ciency, safety and uptime of the pumping systems can be increased by selecting the optimal pump technology for the application and using appropriate wear-resistant construction materials.

Although pumping and conveyance of abrasive substances can be routine mining practice, it is important not to let complacency allow environmental contamination or put workers at risk. Some mining operations deal in acidic materials or hazardous chemicals. If the right mechanical seal or sealing option is not used on the pump transporting these materials they could leak and cause dangerous contamination. In dewatering systems, such as a traveller 31

system or a skid, moving belts, rotating pieces of machinery and open tanks are a safety concern for employees. Mining in volatile conditions must be done with the utmost care. In the case of uranium yellow cake, prevention of leaks and exposure hazards is especially important. Improper seals can allow hazard process fl uid to contaminate the atmosphere and potentially endanger personnel. When mining in explosive areas the electric components of mining equipment in motors, control panels and VFDs also need to be properly designed to ensure safety. All mined substances must be

properly conveyed and not all pipes and pumps are prepared to do the job. T e most-used pump in the mining industry is a centrifugal pump, which uses a rotating impeller to move water and other fl uids. Although this is a convenient way to pump water, fl uids containing solids such as those encountered in mining operations pose a problem. T e mineral slurries and the fl uid pumped for dewatering can cause considerable wear on the

internal workings of the pump, leading to frequent replacement and extra cost. T e problem with these pumps is that they are composed mostly of hard metal and are capable of high fl ow rates. Usually this is desired. T e faster a fl uid can be pumped, the faster the job is done. However, in the case of abrasive fl uids and fl uids fi lled with particulates and solids, the pump only throws these solids against its metal harder and faster. T is causes signifi cant wear very quickly and can eventually compromise the entire process. When considering dosing applications, centrifugal pumps are not an eff ective solution because they do not produce a precise fl ow and can shear fl uids such as fl occulants, which reduces the effi ciency and eff ectiveness of the dosing process. In many cases, to combat this problem in dosing, positive displacement pumps such as hose pumps or diaphragm pumps are used instead. However, these pumps, while better at metering, have pulsation – and if not properly prepared to deal with damage, can lead to costly consequences. For

Yellow cake uranium centrifuge discharge

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