Look behind the scenes
Until January 2017, a copper beneficiation plant in Zambia was using pumps from six different manufacturers. Attributable to the large number of different models, this resulted in a steadily growing inventory of similar spare parts and maintenance procedures. Thereby, the effort and costs for necessary maintenance of the pumps were constantly increasing as a result. Following a thorough review of the reliability and service life of its pumps, the plant operator decided to simplify its spare parts inventory and maintenance - and only use pumps from a single supplier. NETZSCH, represented by its subsidiary in South Africa, was chosen for the reliability of its pumps. The Zambian company replaced 36 pumps for polymer applications and saved 1 million dollars by reducing its spare parts inventory as well. Its reagent pumps were then also optimised, as the existing solution could not provide the required capacity or achieve the necessary precision and reliability.
Once the polymer pumps had been successfully standardised, NETZSCH was also asked to prepare possible ways to optimise the reagent pumps on site. The pumps that had been originally installed for this application were not delivering the required capacity. They also lacked the accuracy that was needed and were not reliable. "A special solution was necessary, because the pumps had to be attached to the floatation cells above and it proved difficult and time-consuming to make the necessary changes on site", explains Willis. The flotation cells are three storeys high, so changes would have meant working at height and in restricted space and would have required official permits for hot work. The new equipment would also have had to have been safely transported up to the cells first.
"Instead, we recommended a plug&play system preassembled on a base frame." This allowed the operator of the treatment plant to remove all the existing equipment and simply bring the frame into position. This avoided extensive welding work and production on site or at height on the cells. The system had to be specially made for the application. As the space was limited, NETZSCH came up with a particularly compact frame design. The three single frames with space for two pumps each, including central distribution pipes, seal support system and lowering pipes, are designed as a modular system. They can be easily combined, because the product intake and outflow lines and the distribution pipes of the mechanical seal support system can be easily connected. The frame can also be used in temporary installations. They are fitted with forklift guides and crane attachment hooks, so chemical can be fed straight from an IBC tank to the pumps. "Installing new frames meant the operator could rationalise its spare parts inventory for this application as well and increase plant availability", says Willis. "This complete solution also gave the customer the option of not contracting with anyone else to simplify execution of the project." The frames designed by NETZSCH have a lot of potential for adaptation too. "We can install waste containers above the pumps and put in flow controllers, pressure monitoring systems and local control unit", explains Roger Willis.