Inco plans to spend $500 million to cut acid rain emissions

Inco Ltd. (TSE) has advised the Ontario government that it will spend nearly $500 million over the next five years to reduce sulphur dioxide (SO2) emissions from its Sudbury, Ont., smelter complex. Emissions will be reduced by some 60% to a level of 265,000 tonnes per year by 1994, as called for under the Ontario Ministry of the Environment’s “Countdown Acid Rain” regulation. Details of the SO2 abatement program are set out in the last of six semi-annual reports to the ministry, submitted by the company at year- end 1988.

The total cost of the program is estimated at $494 million, comprising a previously announced expenditure of $69 million to consolidate and modify milling and concentrating operations and $425 million for smelter SO2 abatement. The smelter program calls for new oxygen flash smelting furnaces, a new sulphuric acid plant, and additional oxygen plant and other plant modifications.

The reduction in SO2 emissions under the Inco initiative will be achieved principally through the implementation of two key changes in process technology. First, new milling technology will permit the rejection of additional amounts of pyrrhotite, the high sulphur-bearing portion of the ore, prior to smelting. Secondly, bulk copper- nickel concentrate, rather than separate concentrates, will be produced and smelted in Inco-developed oxygen flash furnaces, which will replace existing reverberatory furnaces. This will permit the production and capture of high strength SO2 gas, which can be converted to sulphuric acid. In total, 90% of the sulphur content of Inco’s Sudbury or will be contained when the project is completed.

The $69 million milling portion of the project will be a stand-alone economic program, with an estimated discounted cash flow rate of return of 22.5%. Financial evaluation of the $425 million smelter SO2 abatement portion of the project indicates a discounted cash flow rate of return of 5.9%, justifiable only as a means to reduce SO2 emissions. Roy Aitken, executive vice- president of Inco responsible for environmental affairs, said the company will not request financial assistance from either the federal or provincial government to implement the project. He added: “We do expect, however, that any tax incentives or other considerations applicable to environmental installations or improvements will be fully available to the project, which is a major element in Canada’s program to meet and hopefully better its target for reduction of SO2 emissions by 1994.”

Aitken said that the project schedule is tight, and that work has already begun on detailed design engineering and procurement. Construction must get under way early this year in order to meet the 1994 target date, he said. Provided that construction of the first of two furnaces for smelting the bulk concentrate is completed as planned by late 1991, along with the new acid plant and additional oxygen plant, a significant reduction in SO2 emissions, about 100,000 tonnes per year, could be realized earlier than 1994, he said.

He said that Inco is continuing to study ways to reduce emissions from the Sudbury smelter to 175,000 tonnes per year, as requested by the Ontario government. The company has applied to the federal department of Industry, Science and Technology for funding assistance to conduct research and development at its Port Colborne, Ont., research stations on innovative new Inco technology for matte converting to achieve further reductions.

Aitken credited the company’s research and development effort for achieving the optimum solution to the problems posed by the 1994 emissions reduction requirement.