Due to its ability to extract very high percentages of the available seam, longwall mining now accounts for nearly 50% of all underground mining operations. However, any mining operation comes with a host of hazards which must be minimised as far as possible. Modern techniques and equipment have made significant improvements in production efficiency as well as safety.
The principle of longwall mining is the use of a large cutting head or shearer which traverses the coal seam breaking it up and depositing the coal onto an armoured conveyor to transport the coal away from the face of the mine. This operation is protected by a series of hydraulic roof supports which prevent the mine roof from collapsing by applying huge pressures to support the rock above.
Each roof support is capable of independent movement so once the shearer has passed by, the support can lower itself away from the roof and advance forward to fill the space left by the shearer. In this way the roof support system maintains a safe haven for the miners and their equipment to operate in, all the time moving forward as the coal seam is mined and allowing a controlled collapse of the roof.
In this mining system, hydraulic power is required for a range of equipment – including roof support structures – and it must be designed and engineered to meet all the current regulations on coal mining equipment as well as being robust, reliable and efficient. RMI Pressure Systems has been developing and supplying high pressure pumping systems for the mining industry for many years, using the latest technology and years of experience to produce market leading products.
Working closely with industry experts, RMI has a reputation for supplying some of the most reliable high pressure pumping systems available. With systems being used in safety critical functions, it is essential that the reliability is beyond question; requiring months of continuous testing before being accepted for operational duty. This reliability is dependent on specifying the best quality components and materials to manufacture pumps using the latest design and manufacturing techniques to exacting tolerances.
RMI also has a policy of continuous development of energy efficient products, which has led to the introduction of the ODIN (On Demand Intelligence) control system. This system uses a range of data supplied from equipment used in the process of continuous longwall mining and uses it to calculate the changes in demand for hydraulic fluid before they occur. In this way ODIN can modulate the pump speed and change the flow and pressure characteristics to meet demand in the most responsive way possible.
All of the equipment that is employed in the longwall mining process is extremely expensive and corresponds to a very significant investment on the part of the mining company, so when the longwall is exhausted, this equipment needs to be recovered and relocated. This retrieval process can require the use of salvage pump units, which can be installed to provide hydraulic power while the main systems are disconnected and relocated.
RMI has developed a salvage pack, contained within a steel framed skid, which is specifically designed for this purpose and can be specified to suit the exact requirements of the customer to ensure that reliable hydraulic power is provided during the relocation process. Optimised for operations within a mining environment, the salvage pack is fully flameproof with all the necessary operational and safety indicators.
Mike Sherman, RMI Marketing Manager, comments “As one of the world’s leading manufacturers of high pressure, high flow pumping systems, RMI has been designing solutions for the mining industry for many years. With the majority of applications in remote areas with limited access, and where unplanned downtime is very expensive, reliability is an essential quality required of our equipment. We have an enviable reputation for designing efficient and reliable equipment, which has been used across the world in the longwall mining industry for many years.”