Characterization and Process Optimization in the Extraction of Gold

Abstract

Refractory gold ore understudied showed traces amount of gold from X-ray fluorescence analysis. Phases identified are quartz, muscovite and calcite. Statistical approach using response surface methodology - central composite design were performed at varying concentration of NaCN, Pb (NO3)2 and H2O2. Cyanidation experiments were conducted at room temperature at pH 11. Using the response surface methodology followed by path of steepest ascent, gold cyanidation was found to be at 467.3 ppm NaCN, 94.96 ppm Pb (NO3)2 and 0.01M H2O2, at the vicinity towards the optimum condition where 88.97% Au extracted from the ore, equivalent to 1.7231 g/t Au.

Effect of hydrogen peroxide and lead(II) nitrate on gold cyanide leaching of Malaysian mesothermal deposit gold ore

“…On the other hand, the maximum amount of gold recovery (79.81%) was associated with the run #10 with the experimental conditions of 410 ppm H2O2, 50.00 ppm Pb(NO3)2, and 500.00 ppm NaCN. The analysis of variance (ANOVA) results by Design Expert 11 software suggested the Quadratic model for inverse transformation of gold cyanidation based on the low standard deviation, high R 2 and adjusted-R 2 values, lowest p-value, and with probability F < 0.0001, which indicates the model is significant (Ong et al, 2015). The models were developed based on the highest order polynomials, where additional terms were significant and the model was not aliased as shown in Table 6.…”