JOHANNESBURG (miningweekly.com) - The world's second-largest platinum producer Impala Platinum (Implats) said on Monday that its refined platinum production had decreased by 4% in the March quarter, compared with a year earlier.

The company produced 368 000 oz of platinum in the period under review, which was less than the 385 000 oz produced in the March 2009 quarter.

However, for the nine-months ended March 31, 2010, platinum output remained unchanged compared to the same period the previous year, despite industrial action and a significant accident at its operations in Rustenburg.

Meanwhile, palladium production rose 26% in the March quarter, compared with the same period a year earlier, on the back of the ramp-up of the phase-one expansion at Zimplats, additional deliveries of palladium-richer autocatalysts and the continued destocking of material from the refinery. It produced 283 000 oz of palladium in the quarter.

At the company's Impala Rustenburg operations, tons milled declined by 5% to 3,2-million, owing to a change in the mechanised Merensky mining layout.

Refined platinum production at the mine rose 44% to 220 000 oz, largely as a result of a lock-up of material in the previous comparable period caused by the commissioning of the gas cleaning plant in the smelter.

Implats said that despite the change to a more UG2-dominant ore mix, head grade, recovery and yield had all shown improvement. "The focus at the operation remains on on-reef development at the current shafts and main development at the project shafts. Mining flexibility will be restored by accessing new half-levels, particularly in Merensky areas."

Further, tons milled at the company's Marula operations on the eastern limb of the South African Bushveld Complex fell by 15%, while platinum in concentrate production declined by 22% to 14 000 oz, owing to pipeline movements. "Constrained mining flexibility continues to hamper the ramp-up to conventional mining."

Platinum production increased in line with the phase one ramp-up of the company's Zimplats operation. "While mill tonnage increased by 93%, platinum in matte, production only increased by 85%, owing to a combination of lower recoveries at the new Ngezi plant, lower platinum grade and inventory movement."

Zimplats had decided to move ahead with the phase-two expansion project, based on existing agreements with the Zimbabwean government and despite the fact that discussions were still on-going on certain key issues around the project.

The estimated cost of this project is $500-million and will be funded by a combination of internally generated cash resources and a bank loan. "Funding arrangements have not yet been finalised and government project approvals are still outstanding," said the company.

Meanwhile, steady-state capacity of 100 000 oz/y of platinum in concentrate had been achieved at the company's Mimosa operations on the Wedza Geological Complex on the Zimbabwean Great Dyke east of Bulawayo.

Consequently, tonnes milled rose only marginally to 557 000 t, while platinum in concentrate production increased by 6% to 25 000 oz period-on-period.

South Africa produces four fifths of the world's platinum, which is mostly used in making catalytic converters to cut pollutants from car exhausts, and in jewellery.