JOHANNESBURG (miningweekly.com) – The commissioning of the Bozshakol and Aktogay mines has seen KAZ Minerals achieve an 80% increase in its copper production last year and has helped its gold output to be at the top of its production guidance, the Kazakhstan miner reported on Thursday.

In its fourth-quarter and full-year ended December 2017 production report, the company said that it had produced 258 500 t of copper, including 101 300 t from Bozshakol, in the Pavlodar region, and 166 400 t from Aktogay, in the East region.

The balance came from the East Region and Bozymchak operations, which produced 67 000 t.

Full-year copper production exceeds the February 2017 guidance of 225 000 t to 260 000 t and is in line with the updated range of 250 000 t to 270 000 t that KAZ provided in the second half of the year.

Fourth-quarter copper production of 65 200 t increased from a year earlier output, but was lower than the third-quarter production of 75 300 t. KAZ explained that the 13% quarter-on-quarter decrease was as a result of maintenance at Bozshakol and a lower average copper grade processed at Aktogay.

A 13-day maintenance period at Bozshakol for mill relining and equipment repairs impacted on the December quarter processing volumes, which decreased to 11.4-million tonnes, from 12-million tonnes in the previous quarter.

Ore extraction decreased from 17-million tonnes to 13.4-million tonnes, as the quantity of clay ore required to be extracted at Bozshakol to access sulphide ore reduced significantly.

Full-year gold production was at the upper end of its 160 000 oz to 180 000 oz guidance range, coming in at 178 700 oz for the 12-month period. Fourth quarter gold output, however, was lower on a quarter-on-quarter and year-on-year basis.

Silver production was in line with expectations at 3.5-million ounces, but zinc in concentrate output at 57 600 t fell short of the guidance range 60 000 t to 65 000 t, owing to delayed access to higher grade zones in the East region.