Drainage is an important issue for most mines. In fact, few mines around the world do not have to worry about drainage problems. There is often a large amount of water that needs to be discharged and mining can not be done without proper treatment of the water. Ola Hallgren gave us some guidance. There are several pump types that can be used for mine drainage. The biggest advantage of electric submersible pump is easy to install, plug and play. It is also handy when the number of pumps needs to be changed. Electric submersible pumps are usually easier to service than other types of pumps. Because submersible pumps weigh anywhere from 25-550 kg, smaller pumps can be handled by hand only. Larger pump also only conventional mining equipment in the mine can easily get done. Mine Wastewater Mine waste water is rarely clean H2O, often containing solid and insoluble chemicals that can cause erosion of pumps, valves, and other drainage equipment. The solids in mine waste water are often the ultimate consideration for pump selection. Drainage pumps Drainage pumps, the most commonly used type of pump in mines, are used to discharge water containing less corrosive solids such as clays, as well as sand and suspended solids. The maximum solids size is the filter pore size (usually 7 to 12 mm). Due to the abrasive nature of the sand on the pump, the concentration should not be too high. Sludge Pumps Sludge pumps are suitable for discharging sludge and are also suitable for discharging water with larger particle size solids. The maximum particle size of the solid is the pump inlet diameter (usually 32 to 80 mm). Mud Pumps Mud pumps are used to treat suspended abrasive solids, such as high concentrations of sand, grit and concrete. To cope with these abrasive substances, the hydraulic components of the mud pump are usually made of NiHard 4, which is one of the hardest materials present. Mud pumps usually have a stirrer to improve performance. Pumping The usual method of draining a mine is to use a small pump (2 to 6 kW) to drain the water from the mine tunnel and route the water to a larger sump. Because small submersible pumps weigh about 5 to 50 kg, it is easy to move them to different locations. The sump is fitted with a large pump (8 to 35 kW) to deliver the water to the next horizontal pumping station. These pumps weigh between 60 and 285 kg. All the water in the pump station is collected from a lower height. The large pump weighs about 285-550 kg and the maximum transport capacity is 100 meters. The function of the shut-off valve is very important in transporting water from one level to another. It ensures that water does not flow back into the pump when the pump is shut down. Sediments Sedimentation ponds may be necessary if the water contains sand, grit, or smaller stones. In the sedimentation tank, solids stay at the bottom, making water easier to handle. Empty the solids as long as a replaceable container is used in the sedimentation tank system. Open pit mining Pumping flow required for open pit mining depends to a large extent on the size of the mine, groundwater conditions and precipitation. Abrasive-resistant submersible pumps are always the best choice because they operate in extremely harsh conditions, while open pit mining is often harsh. As the water level changes from time to time, it is recommended to place the pump on a stand so that it moves with the water. Otherwise, the pump may sneak into the sand or clay. To control the delivery head, several pumps can be connected into a series. Intermediate reservoirs can also solve these problems. Tips â—† Avoid hose knots and sharp bends, which can affect pumping efficiency. â—† Make sure the pump will not get trapped in sand or clay, and place the pump on a thick plank or rough rock. You can also place the pump on a perforated drum. Summary â—† According to the different types of solids in the water pump selection. Drain pump is the most commonly used. â—† How many smaller pumps are distributed evenly in the area where drainage is required? Build a sump, install a large pump (or a few small pumps). These pumps can be automatically controlled by a float switch. â—† When the pump is delivered to another level in the mine, install a check valve. When leaving the site, the water may pass through the sedimentation tank. â—† Do not discharge untreated chemical mine waste into the world without first knowing the local environmental laws. Mine drainage does not require high technology, but should be properly handled to avoid flooding. Contact Phone: +46 8 606 6600 Fax: +46 8 745 53 28 E-mail: www.grindex.com
