00000nam 2200000za 4500 9.841326 CaOODSP 20221107152047 cr ||||||||||| 170809s1969 oncad ob f000 0 eng d CaOODSP eng eng fre n-cn--- n-cn-on M34-20/107E-PDF M34-20/107 Lucas, B. H. Reduction of ferric iron by SO2 with heat or SO2 with activated carbon [electronic resource] / B.H. Lucas and G.M. Ritcey, Extraction Metallurgy Division. Ottawa : Queen's Printer, 1969. iv, 16 p. : charts, ill. Technical bulletin ; TB 107 Cover title. "May 1969." Digitized edition from print [produced by Natural Resources Canada]. Includes bibliographical references. “In a liquid-liquid system for the separation and recovery of individual rare earths, co-extraction of ferric iron is a serious problem. This study was done to determine whether the problem could be solved by converting the iron to the ferrous state, as opposed to precipitating the ferric iron to remove it from solution. In the precipitation of ferric iron, some co-precipitation of rare earths occurs. A synthetic iron solution, and a uranium barren solution containing 3.17 g Fe+2/1 and 0.34 g Fe+3/1, were used in the test work. The ferric iron in the barren solution was reduced by 90% at 90 °C in 31 minutes by addition of twice the stoichiometric amount of SO2. An alternate method used 1.5 times the stoichiometric amount of SO2 at room temperature and 15 g/1 activated carbon; retention time was 15 minutes. All of the test work was carried out in an oxygen-free system. On the basis of this work the activated carbon-SO2 method was the more economical. Measurement of the oxidation potential can be used as a method of control"--Synopsis, p. i. Includes synopsis in French. gccst Metals gccst Processing Ritcey, G. M. Canada. Natural Resources Canada. Canada. Mines Branch. Technical bulletin (Canada. Dept. of Energy, Mines and Resources. Mines Branch) TB 107 (CaOODSP)9.834857 PDF 1.73 MB https://publications.gc.ca/collections/collection_2017/rncan-nrcan/M34-20/M34-20-107-eng.pdf 299993