Leaching of malachite using 5-sulfosalicylic acid

Abstract

Abstract In this study, an attractive organic complexation reaction reagent with copper ions was developed for copper leaching from copper oxide ores. The possible chemical reactions of 5-sulfosalicylic acid (5-SSA) in the malachite aqueous solution were determined. Moreover, the influences of various factors, such as time, stirring speed, temperature, reagent concentration and particle size, on the leaching of copper oxide ore were investigated to establish the reaction kinetics. Results show that 5-SSA not only provided an acidic medium but also served as a complexation reaction reagent with copper ions in the solution; thus, 5-SSA exhibited a novel leaching effect on copper oxide ores. The influence of temperature, reagent concentration and ore particle size on the leaching rate of copper was significant. The reaction kinetic equation associated with these major factors was constructed as 1−(1− x ) −1/3 =[0.0021 ( C ) 0.638 ( P ) 0.765 exp(−5103 T )] t , with the reaction activation energy of 42.43 kJ/mol. At the same time, the stirring speed exhibited nearly no effect on the leaching rate of copper, and the dissolution process was controlled by chemical reaction. 5-SSA is therefore a new attractive reagent for copper extraction and can be extended to the metal recovery of other metal oxide ores.