One component of First Quantum Minerals’ massive investment in the Zambian copper belt is the copper solvent extraction (SX) circuit at Kansanshi. The centrifuge which is installed is a three phase separator known as a TRICANTER®. The unit’s purpose is to remove the crud (an accumulation of solid impurities) from the organic solution of the Kansanshi SX circuit, thereby limiting costly organic losses from the system.
The Kansanshi mine, located near the town of Solwezi in north western Zambia – just 15 km from the border of the Democratic republic of Congo, is the third copper refinery in Zambia to adopt Flottweg TRIICANTER® centrifuge technology for SX crud removal. Flottweg’s agent in South Africa, Nils Schwarz of Schwarz Global Consulting says that the Flottweg TRICANTER® centrifuge already has a solid track record in SX crud removal; as such units have been used successfully for a number of years in Chilean copper refineries. While organic consumption will vary from refinery to refinery, the use of a Flottweg SORTICANTER® can reduce organic consumption by as much as 25 %.
Crud is a persistent problem in most solvent extraction circuits. While small amounts of crud actually aid the separation of the aqueous and organic phases, the quantity of crud rapidly builds up in the settlers and can severely disrupt the SX system. The crud therefore has to be pumped from the settlers on a regular basis. Due to the high value of the organic solution, it is essential that as much of it as possible is recovered from the crud. The conventional method of filtering the crud results in substantial losses of organic which, apart being a major economic loss, also presents an environmental disposal problem. The Flottweg Tricanter® centrifuge is able to separate the solid crude phase, as well as the entrained aqueous phase, to return clean organic to the SX circuit.
Flottweg is one of the world’s leading producers of solid bowl centrifuges. Over the years Flottweg has developed considerable know-how in all kinds of separation applications. Flottweg’s current product range comprises decanter and disc stack centrifuges as well as belt presses and covers all capacities from pilot plant to large continuously operating machines for industrial use. Flottweg products are well received in the mining, petro-chemical, chemical, pharmaceutical, food and machining industry as well as in environmental treatment. Flottweg centrifuges are used throughout the mining and metallurgical industry for applications as diverse as dewatering products such as uranium yellow cake, clarification of industrial waste water, and drilling mud recovery. The company is headquartered in Germany with sales offices and service stations all over the world.