AN incident at the solvent extraction (SX) section of Central Asia Metals (CAM) Kounrad copper cathode producing facility in Kazakhstan in June has led to the company reducing its production target for 2015. The target has been revised down from 13,000 tonnes of cathode copper to 12,000 tonnes.

During normal production on June 26 a problem occurred in the SX section which resulted in a significant quantity of the organic inventory being lost to the dumps within a very short time frame. After inspection, it was identified that one of nine weir plates in the mixer settler had fallen out of position, resulting in the ability of the organic inventory to escape from the circuit onto the dumps.

The problem was rectified the following day and the plant was started again but at a much lower flow rate. This continued for several days until the site team stabilized the plant and determined the full extent of the loss of organic inventory.

CAM’s CEO Nick Clarke said the company would strive throughout the remainder of 2015 to mitigate the position but estimated the impact on guidance would be approximately 1000 tonnes.

Less than a year after the start of the Kounrad Stage 1 Expansion program, the SX-EW extension was successfully commissioned in May. The US$13.4 million program included construction works and equipment installation for the extended SX-EW facilities, all undertaken by company personnel.

The extra mixer-settler tank increased hourly solution treatment capacity by 33% to 1200 cubic metres and the additional 24 electro-winning cells increased daily plating capability by 42% to 50 tonnes of copper. The upgrade also included installation of an additional 10MW transformer substation.

The expansion and additional 5.6MW boiler capacity installed towards the end of 2014 increased name-plate annual capacity from 10,000 to 15,000 tonnes of cathode copper. While the incident reduced 2015 guidance, the company remains on track to achieve 15,000 tonnes in 2016.

In early July Nick Clarke said the Kounrad SX-EW plant had operated for 38 months at an average utilization rate of 98%, and the incident was the first such interruption in production.

In the second quarter of 2015 the plant produced 3093 tonnes while in the first half it produced 5444 tonnes, up 6.9% on the 5094 tonnes produced in the first half of 2014. The increase was largely due to the expanded boiler-house capacity resulting in higher solution volume treatment rates during winter.