|
e 1. 1t/9? 17 15 S 171967'L33ti3 6PT7LE MT. GOLD
<br />
<br />J. J. BYERLEY ET AL
<br />?[
<br />
<br />7
<br />
<br />5
<br />found to be composed musty of copper. Table 7 summarizes
<br />the results of these experiments in which the pH sclec[ed was
<br />3.0-3.2. The optimum pH observed for nickel precipitation.
<br />Included in Table 7 are ealcula[ed values of the Fraction of
<br />copper and nickel precipitated. The agreement u Fairly good
<br />except in the wse of solution $-5 where the fraction of copper
<br />precipitated was found to be 411.9% compared to the
<br />calculated value aF61.8%. The total cyanide balance obtained
<br />by d'uect analysis of the test solution also confirmed the
<br />assumption the[ nieke] precipitates as Nii(CN)q and copper
<br />precipitates as CuCN. Table 8 shows the results of additional
<br />acidification tests where solutions B-5 and B-7 were acidified
<br />to pH 2.7 which corresponds to the next lowest pH value given
<br />in Table 4. More copper isprrrapitated as exptcted, howevcy
<br />the fraction of nickel removed from solution is reduced.
<br />Overall it is clear that the precipitation of nickel cyanide ;s a
<br />slow process regtLiring conddcrable time to equilibrate. Any
<br />copper wcxLCting in the solutions still precipitates rapidly as
<br />copper cyanide but the precipitation of nickel cymide is not
<br />improved.
<br />The conditions for precipitation of copper and nickel cyanide
<br />obtained bom theoretically and experimentally in thu work
<br />call ptovide useful data for the design of a prccip;tatioa wage
<br />is an overall effluent treatment strategy. Of special
<br />importance is the preapitation effictieney which is an
<br />ImpArfartt fartnr in Ihr decigtt of follounngion exuhne6a atnpa.
<br />,REFERENCES
<br />American Publle IIealth Association (1971) 'Standard
<br />Method for the Ixantina[ion of Water and Wade Water', Am.
<br />Water Works Assoc. and Water Poll. Contr. Pcd~ 13th
<br />Edition.
<br />Byerley, J. J. and Enns, H• Field Information
<br />Byerley, J. J. and Enos, ld. (1984) CIM Bulletin, r1, 841.
<br />Byerley, J. J; Atkinson, G. F. and Mitchell, $. J. (19$2)
<br />Analyst,l[Y7, 398-~W'L
<br />Capper, D. nod Plat, R A. (1966) Inorg. Chem. 5 (1),16-2D.
<br />Flume, D. N. and SolthoR, I. M. (1950) ].Amer. Chem. Soc.,
<br />72,4423.4.
<br />Iran, R M.; Christensen, J. J.; Hansen, J. W. and Watt, G. D.
<br />(1945) [norg. Chem. 4, 77.8-21.
<br />Le, V. T. (1978) MASC. Thesis, University of W aterloo.
<br />Noblitt, K L. (1973) Repot[ R-26S, Department of Energy,
<br />Mines Branch, Ottawa.
<br />P. 09
<br />8i7
<br />Peaneman, R A. andJones, L" H. (1456) J. Chem. Phys.24 (2~
<br />243-b.
<br />Sharpe, A. G. (1976) "The Chemistry of Cyano Complexes of
<br />the Tzansidoa Metals",Academic Press, London.
<br />Sillen, L. G. (1964) "Stabifiry Constants of Metal-Ion
<br />Complexes", Special Publication No. 17, The Chemical
<br />Sodety, London.
<br />Sillen, L. G. (1971) "Stability Constants of Metal-Ion
<br />Complexes - Supplement No. 1", Special Publication No. 25,
<br />The Chemical Society, London.
<br />Snopety S. (1986) M.A.Sc. Thesis, University of Waterloo.
<br />Trang, C. V. (1985) MASa Thesis, University of Waterloo.
<br />US Patentd519880.
<br />US Patentd524662.
<br />
<br />
<br />
<br />-339- RANDGL GOLD FORUM 86
<br />
|