Application of Air to Jeffrey Mill of the Asbestos Canadian Milling Johns at the New Manville Company, Limited, Asbestos, Que.
This paper discusses the methods of handling air in a large asbestos mill presently being completed at the Jeffrey mine of the Canadian Johns Manville Company in Asbestos, Quebec. The mill, being the largest single asbestos producer in the world and capable of handling over 14,000 tons of ore per day, requires vast quantities of air. A minimum of 2,500,000 c.f.m. is required or about 10 tons of air for each ton of ore milled. Short descriptions of the process and systems requiring this air are given, followed by details of the fans and filters which make up the heart of the mill. This 'draw through' system, located on the top or 12th floor, is an automatically .controlled volume-pressure system creating the required suction to draw .air throughout the mill building and its numerous air systems. The dry mechanical method of milling develops enormous quantities of airborne dust and fibre. A section of this paper is devoted to a description of the multiplicity of dust systems within a system to control, filter, and remove this dust. Finally, the paper describes the method of returning the filtered air to the working floors or to the outside, with some notes on heat, humidity and dust counts.