00000nam 2200000za 4500 9.841172 CaOODSP 20221107152025 cr ||||||||||| 170808s1966 oncad ob f000 0 eng d CaOODSP eng eng fre n-cn-qu M34-20/76E-PDF M34-20/76 Kelly, F. J. A comparison of manual and automatic control of the grinding circuit at East Malartic Mines Limited, Norrie, Quebec [electronic resource] / F.J. Kelly and W.A. Gow, Extraction Metallurgy Division. Ottawa : Queen's Printer, 1966. iv, 18 p. : charts, ill. Technical bulletin ; TB 76 Cover title. "September 1966." Digitized edition from print [produced by Natural Resources Canada]. Includes bibliographical references. “Surveys were made of the East Malartic Mines Limited grinding circuit while it was under manual control and when it was under automatic control. The automatic control system used involved the measurement of the intensity of a narrow frequency range of the sound emanating from the grinding units, and control of the feed rate so as to maintain the sound intensity at a pre-set value. Eighty per cent of the control signal came from the primary open-circuit rod mill and the remaining twenty per cent from one of two secondary ball mills operating in parallel in closed circuit with hydraulic cyclones. The surveys showed that the application of automatic control resulted in a significant reduction in the variability of the fineness of grind, and in the variability of the screen analyses, of all the products from the grinding circuit. For example, under manual control the 50% passing size of the rod mill discharge varied from 48 mesh to 150 mesh, while under automatic control the variation was within one Tyler screen size, i.e. from just less than 28 mesh to just less than 35 mesh"--Abstract, p. i. Includes abstract in French. gccst Mining industry gccst Equipment Gow, W. A. Canada. Natural Resources Canada. Canada. Mines Branch. Technical bulletin (Canada. Dept. of Energy, Mines and Resources. Mines Branch) TB 76 (CaOODSP)9.834857 PDF 5.84 MB https://publications.gc.ca/collections/collection_2017/rncan-nrcan/M34-20/M34-20-76-eng.pdf 299963