Kennecott unveils new smelter

As a demonstration of its commitment to environmental protection, Kennecott recently unveiled what it describes as the most advanced copper smelter in the world.

The new US$880-million facility will serve the company’s Bingham Canyon copper-gold-silver-molybdenum mine near Salt Lake City, Utah.

Designed to capture almost all sulphur in the smelting process, the facility will produce 310,000 tons of refined copper each year, which is double the capacity of the previous smelter.

The new plant will also reduce sulphur dioxide emissions to less than 5% of previous emissions. Particulate emissions will be less than one-third the level permitted by the state of Utah.

Using new technology called “flash smelting” and “flash converting,” the smelter allows for copper matte to be quenched in water and then granulated for transport, rather that using the conventional ladle and crane. Granulation of the matte greatly reduces emissions, and allows for the independent operation of the smelting and converting furnaces.

Flash converting, developed in co-operation with Finnish-based Outokumpu, allows for a high volume of gas to be captured and makes it possible for the acid plant to operate more efficiently.

A few problems were encountered prior to the unveiling of the smelter. An explosion in mid-September forced the shutdown of one of two smelting-refining furnaces. And one person was slightly injured when a cooling element leaked water on to molten copper in the furnace.

The damaged furnace will remain inoperable for six to eight weeks.

Nevertheless, Kennecott expects the facility to be operating at capacity in the first quarter of 1996.

The increased capacity will allow Kennecott to process all of its concentrates on site, so that it will no longer have to ship a certain portion elsewhere, as was previously required.

The smelter is part of a US$1.5-billion expansion program which began in 1985. In addition, the refinery was fitted with a robotics systems, and includes a facility for producing byproduct gold and silver from the Bingham Canyon mine.

Expansion of the tailings impoundment will continue until the end of the decade, at a cost of US$500 million. This brings the total cost of the modification program to more than US$2 billion.