Bozshakol Clay Project

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Copper flotation processes to upgrade clay ore

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:

  • Input and management of metallurgical test program
  • Evaluation of metallurgical test results
  • Design of process flowsheet
  • Development of process plant 3D model and basic engineering
  • Development of the interfaces with the sulphide plant, including impact on plant and infrastructure
  • Capital and operating cost estimate to +15-10% accuracy
  • Engineering and cost estimate report.

Key challenges included:

  • Converting the clay ore into a slurry
  • Developing a process flowsheet that achieves acceptable recoveries given the fine nature of the ore and multiple mineral types
  • Operating in low temperatures, especially considering the volumes of water required for the proposed flowsheet.

Project details

Republic of Kazakhstan
Business line
Minerals & Metals
Kazakhmys Bozshakol LLP
2011 - 2012
Solution phase
Evaluate (FS)
Studies and technical solutions