Open AccessA statistical approach to the experimental design of the sulfuric acid leaching of gold-copper ore
Author(s) -
F.D. Mendes,
Afonso Henriques Martins
Publication year - 2003
Publication title -
brazilian journal of chemical engineering/brazilian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.313
H-Index - 52
eISSN - 1678-4383
pISSN - 0104-6632
DOI - 10.1590/s0104-66322003000300010
Subject(s) - sulfuric acid , copper , leaching (pedology) , metallurgy , gold cyanidation , factorial experiment , copper extraction techniques , reagent , iron oxide copper gold ore deposits , lixiviant , chemistry , hydrometallurgy , materials science , environmental science , mathematics , statistics , quartz , fluid inclusions , soil science , cyanide , soil water
The high grade of copper in the Igarapé Bahia (Brazil) gold-copper ore prevents the direct application of the classic cyanidation process. Copper oxides and sulfides react with cyanides in solution, causing a high consumption of leach reagent and thereby raising processing costs and decreasing recovery of gold. Studies have showm that a feasible route for this ore would be a pretreatment for copper minerals removal prior to the cyanidation stage. The goal of this experimental work was to study the experimental conditions required for copper removal from Igarapé Bahia gold-copper ore by sulfuric acid leaching by applying a statistical approach to the experimental design. By using the Plackett Burman method, it was possible to select the variables that had the largest influence on the percentage of copper extracted at the sulfuric acid leaching stage. These were temperature of leach solution, stirring speed, concentration of sulfuric acid in the leach solution and particle size of the ore. The influence of the individual effects of these variables and their interactions on the experimental response were analyzed by applying the replicated full factorial design method. Finally, the selected variables were optimized by the ascending path statistical method, which determined the best experimental conditions for leaching to achieve the highest percentage of copper extracted. Using the optimized conditions, the best leaching results showed a copper extraction of 75.5%