青化法に於ける金の溶解に關する基礎的研究 (第6報)
金鑛青化試驗に於ける諸因子の影響
1949 年 65 巻 736 号 p. 258-264
詳細
1949 年 65 巻 736 号 p. 258-264
The cyanidation tests were undertaken with the aim of examining the effect of the variables influencing the extraction of gold. from T, S and 0 ores by means of a miniature Pachuca tank.
(1) the rate of dissolution of gold increases greatly with the increase in amount of solution within a range of the water-solid ratio from 1: 1 to 10: 1 and shows no apprecidble inkrease between W/S=10: 1 and 20: 1.
(2) In the cases of T and S ores on taining a large amount of argentite, the rate of dissolution of gold increases rapidly as the strength of cyanide solution rises.to about. 0.03 per cent and then increasos slightlg as the strength rises from 0.03 per cent. to 0.80 per cent. the latter slight increase of the rate of dissolution seems to be due to the fact that sonic potions of argentite frequently contain gold particls and dissolve more rapidly with -the increase in the strength of cgnaide solution, revealing gold particles incased. In the case of O ore containing very small amount of aentite the into of dissolution does not make appreciablein crease between 0.03 per cent. and 0.30 per cent. this behaviOur appears to be in accord with the thehry founded by the author's pre ceding research.
(3) In the case of T ore the dissolution rate of gold decreases sensibly at high concentration of lime, while it' increases remarkably in the case of S and O ores, at-high concentration oflime. The latter unexpected increases of the dissolution rate seems to be due to the presence of lead Minerals in the case of S are ard. due to that of soluble. iron compounds-in the case of O ore.
(4) The dissolution rate tends to increase rapidly as the additional amount of lead acetate increases, reaches a maximum at a certain concentration and then degreases. The ffect of lead ac tate on the dissolution of gold is found to be independent of its effect upon the argentite dissolution. This fact is nearly in accor with the theory founded by the author's previous iesearch.
(5) Utilizing the condition proved to be most suitable by the above-mentioned tests, the ultimate extractionpercentages of gold and silver in 0.08 per cent. cyanide solutions are obtained Its follows: in T are it attains 96% Au and 80% Ag a Iter 24hrs, S are 99% Au and 96% Ag after 72hrs and Oore 100% Au and 100% Ag after 12 hrs.
