CROSS-CUTS Missiles for mines

Manitoba engineers and scientists are using bacteria, rockets and computers in the war against unsafe, uproductive and uprofitable mines. The new techniques are being studied under a $25-million research program that falls under the Canada-Manitoba mineral development agreement. Hudson Bay Mining and Smelting and Sherritt Gordon Mines are attempting to recover base metals in underground mining operations by in-situ leaching. Researche rs at the University of Manitoba have isolated bacterial strains indigenous to H udson Bay’s mine at Flin Flon and Sherritt’s Ruttan operation (recently purchase d by Hudson Bay) at Leaf Rapids. The solutions are now being tested on previousl y uneconomic ore types at these mines. The bug’s metabolic processes attack and oxidize the mineral sulphides, dissolving valuable metals into solutions which a re then recovered in a surface treatment plant.

Inco is studying the use of rocket launching to bring down hang-ups in stopes and ore passes. The same principles are applied to avalanche control in mountain ous areas and the company feels the technique could enhance mine safety.

The Manitoba mines ministry is involved in a program of adapting commercial so ftware now used in interactive graphics for underground mine design feasibility. Along the same lines, Inco is looking for ways to reduce the crown pillar of a mine from underground, thereby maximizing ore recovery without overlooking safet y. This can be done by increasing the strength of the overburden and glacial till lying above the pillar by chemical or mechanical means. This project also has a bearing on Inco’s open pit at Thompson. By strengthening the overburden surrou nding the pit, the angle of repose can be increased which lessens the amount of stripping. At the Ruttan mine an underground radio and computer system has been installed for testing. This allows voice transmission from remote and isolated areas of the mine along with the transmission of data on underground conditions to surface that can be read by computers.

Three water waste heat recovery projects are under way as well. Controlled recirculation of underground air at Ruttan provides an economical method of exploiting waste heat and reducing the amount of intake are that has to be heated. Air flow can be decreased when there is reduced levels of diesel exhaust or other po llutants and can be increased when pollution levels are high. Hudson Bay has als o been experimenting with heat pumps to recover cooling water heat from compress ors at its Trout Lake mine and Inco has undertaken studies relating to waste air and water heat recovery at its mine, mill and smelter at Thompson.