Milling and Concentration - Effect of Cyanogen Compounds on the Floatability of Pure Sulfide Minerals.-II

Previous investigations of E. L. Tucker and R. E. Head' related in particular to the effect of cyanogen compounds on galena, sphalerite, and pyrite, and their behavior in the presence of such compounds. The present contribution deals with the floatability of the copper minerals and of pyrite. All experiments were performed on minus 200-mesh material, the method of preparation being the same as that described in the previous article. Flotation tests were made in a small mechanically agitated machine of 50-gm. capacity designed in this laboratory by Gates and Jacobsen.2 General Naval Stores pine oil No. 5 and potassium xanthate were used in constant amount in all of the experiments; these agents were selected because of their present wide use in the flotation of copper minerals. Time additions were varied to secure four final hydrogen ion concentrations, namely, neutral, 0.0005 per cent. CaO, 0.003 per cent. CaO, and 0.02 per cent. CaO. The variation in lime addition was introduced to include the range of alkalinities employed in actual flotation practice. The minerals employed were the purest obtainable. Their analyses are shown in the following tabulation: Table 1.—Analyses of Minerals Employed in Experiments mineral Cu Fe Cao S MgO Insol. Chalcocite .............. 77 02 0.49 0.29 21.70 0.08 0.28 Chalcopyrite............. 34.50 29.20 0.23 34.10 0.07 1.42 Bornite................. 64.30 9.30 0.12 23.70 0.10 1.95 Pyrite....................... 36.90 1.12 49.70 .... 1.51