The Bozshakol Clay Project in Kazakhstan includes the design of a processing plant with the capacity to process clay ore at a rate of 5 Mt/y.
This plant upgrades the ore through standard copper flotation processes. The clay ore is reduced in size to a P80 of 50 mm through a Stammler feeder-breaker and sizer before being converted into a slurry via a SAG mill. Fine clay material (<27 μm) is separated and sent to a fine flotation material while the coarser material is ground to a P80 of <53 μm via a ball mill prior to the coarse flotation circuit.
Two plant designs were completed. In the first, concentrate streams from the coarse and fine flotation circuit were fed into the Bozshakol Sulphide plant at the appropriate locations (regrind circuit, concentrate circuit) depending on concentrate grade and size distribution. In the second, the flowsheet was re-structured to incorporate a regrind mill, cleaner concentrate circuit and filter, resulting in the generation of a copper concentrate on site. All tail streams are thickened before being pumped to the tailings storage facility.
The clay plant is located 3.5 km from the Bozshakol Sulphide plant, adjacent to the sulphide plant crusher.
Ausenco provided the following engineering and cost study services:
Key challenges included: