The Canadian company said operations continued to ramp-up during the March quarter and nickel production of 8573 tonnes was better than expected.

First Quantum said the addition of buffer ponds had improved the overall circuit stability, while also benefitting the sulfuric acid plant, which generates power as a by-product.

C1 cash costs of $US5.69 per pound of payable nickel were also lower than planned due to lower diesel consumption and lower sulfur costs as a result of the use of low-cost sulfur inventory.

The lower sulfur costs accounted for a drop in costs of around 60c/lb, but the company said the low-cost inventory was now depleted.

The plant processed 724,000t ore at a head grade of 1.5% nickel, with recoveries sitting at 78%.

During the quarter, First Quantum sold 5332t nickel at an average realised price of $8.85/lb.

The sales generated revenue of $74.3 million, while the Ravensthorpe operation posted a gross profit of $10.9 million.

The company has forecast production of 36,000-40,000t nickel from Ravensthorpe this year at cash costs of $6.60-6.80/lb.

First Quantum is working to optimise the circuit.

Work is planned to further improve the rejects handling section and the hydrometallurgical pumping capability for additional flexibility in the mixed hydroxide product section, while options are also being explored to improve the payable nickel content in order to recover increased revenues from sales.

Ravensthorpe is expected to average annual nickel concentrate volumes of 28,000t but in the first five years of its 30-year life, rates are expected to be around 39,000t of nickel in concentrate.

The company purchased the nickel plant, which is located 550km southeast of Perth, from BHP Billiton in February 2010 for $350 million and has since spent $303 million on modifications.

First nickel production was achieved at the site on October 4 and 5666t of nickel was produced during the commissioning ramp-up until commercial production was achieved on December 28.

Overall for the March quarter, First Quantum posted record sales revenue of $708.8 million, with Ravensthorpe partially offsetting lower copper prices and sales.

Total gross profit was $270.3 million, while earnings were $119 million.

Aside from Ravensthorpe, First Quantum produces copper and gold from the Kansanshi mine in Zambia and the Guelb Moghrein mine in Mauritania and has several development projects in Zambia and Finland.

This year expected copper and gold production is 270,000-290,000t copper and 170,000-190,000 ounces of gold.

Capital expenditure for the year is expected to be $1.2-1.4 billion.

Shares in First Quantum fell 2.2% in Toronto overnight to $C20.01.