(Sharecast News) - Copper miner Kaz Minerals on Thursday said it was paying an interim dividend of 6 cents a share as pre-tax profits rose to $355m from $240m.Operating profit increased to $464m, up from $291m, while earnings before interest tax depreciation and amortisation were up to $690m from $505m on the back of higher sales volumes.Copper production increased by 18% to 140 kt due to the successful ramp up of the Aktogay sulphide concentrator, Kaz said.Aktogay production rose 83% to 60.5 kt as the sulphide concentrator achieved design capacity, as well as from a sustained high copper grade.Full year copper production guidance was maintained at 270-300 kt and the by-product targets unchanged, Kaz said, adding that the medium term copper market outlook remained positive, "as supply from existing mines declines and demand from both traditional and new sectors continues to grow"."In the second half of 2018 we will focus on sustaining high levels of production at Bozshakol and Aktogay, whilst seeking to maintain our low operating cost position.""Consistent with our positive medium-term view of copper, the Aktogay expansion project will progress over the second half of the year and we will incur limited expenditure on study work on the Baimskaya copper project, pending completion of the transaction expected in the first half of 2019."Kaz Minerals shares fell heavily in early August after it announced a deal to buy a Russian copper project in Baimskaya from a group of investors including Chelsea soccer club owner Roman Abramovich for $900m (£687m) in cash and shares.