Nonlinear dissolution reaction of chalcopyrite

The dissolution experiments of chalcopyrite in 2 mol/L NaCl solutions at 70 degrees C show that the dissolution rate of chalcopyrite oscillates non-pe riodically with reaction time while in acid solutions (pH =1.45-2.45) and f ar from Cu saturation concentration, and Cu concentration oscillates chaoti cally in solution of weak to intermediate acidity (pH = 3.66-7.0). In noneq uilibrium and open systems, the nonlinear coupling between the dissolution of chalcopyrite and formation of cuprous chloride complexes and precipitati on of hemitite caused by Cl-, H+ and O-2 is the internal mechanism of oscil latory changes of dissolution rate, and the nonlinear coupling between the dissolution of chalcopyrite and precipitation of atacamite induced by Cl- a nd H+ has caused the chaotic oscillation of Cu concentration. There are con sistence and difference between reaction rate oscillation and Cu concentrat ion oscillation. However, both of them suggest that the dissolution of chal copyrite in NaCl solution is a nonlinear reaction process.