Nickel Industries' (ASX:NIC) production at its rotary kiln electric furnace operations in Indonesia, in which it holds a 80% indirect interest, clocked in at 31,561 tonnes of nickel metal in the December 2025 quarter, up 1% from the September 2025 quarter's 31,148 tonnes, according to a Thursday Australian bourse filing.

Combined operating cash costs were 2% higher quarter over quarter, primarily due to higher nickel ore costs, somewhat offset by lower electricity costs.

The Excelsior nickel-cobalt project, in which the firm holds a 44% indirect interest currently, started purchasing sulfur and started testing for the first line of the sulfuric acid plant, the filing said. Mechanical tests started on the counter current decantation circuit, thickeners, precipitation tanks, slurry storage tanks, reagent storage tanks, and other associated equipment.

The Hengjaya mine, in which the company holds an 80% interest, reported total ore sales 945,631 wet metric tonnes of nickel ore during the quarter, down 69% quarter over quarter from the 3.1 million tonnes in the previous quarter. The mine is on track to deliver over 1.4 million wet metric tonnes of nickel ore sales in January.

The company's shares fell nearly 1% in recent trading on Thursday.