Prince of Wales opens Inco’s mill, smelter improvements

Nickel producer Inco (TSE) says it has completed 85% of the work required to meet Ontario government regulations for reduced sulphur dioxide emissions at its Sudbury, Ont., facilities.

Inco’s “sulphur dioxide abatement” project, which involves major changes in milling and smelting technology, is designed to contain 90% of the sulphur in ore processed in Sudbury by Jan. 1, 1994, the government deadline. When the project is complete, Inco says it will be able to comply with the new regulations, which stipulate a maximum SO2 emission rate of 265 kilotonnes per year.

On Oct. 24, The Prince of Wales attended a ceremony to officially open the first stage of the project. Inco expects the first of two new oxygen flash furnaces, which will reduce SO2 emissions from the Copper Cliff smelter by at least 100 kilotonnes (15%), to be fully operational by year-end. Although the original budget for the project was $500 million, Inco has already spent $529 million and expects the total capital cost to be $600 million. Strikes during the spring and summer of 1990 and increased materials and construction costs for smelter rehabilitation led to the higher overall costs, the company says.

As part of the program, Inco has expanded and modernized its Clarabelle mill. Conventional 100-cu.-ft. flotation cells have been replaced with jumbo flotation cells of 1,350-cu.-ft. capacity; magnetic separators have been installed to recover and reject pyrrhotite, a sulphide mineral; and the Frood-Stobie mill has been shut down and mothballed.

At the Copper Cliff smelter, a 550-tonne-per-day oxygen plant, a gas-cleaning system and a sulphuric acid plant are already operating. These and other significant changes should lead to productivity gains, dramatic reductions in emissions, and improvements to the smelter as well as the workplace environment, Inco says.