Abstract Kinetics of xanthate ion (X −) sorption on chalcopyrite is studied as a function of concentration (5×10 −5), (2×10 −4), (6×10 −4) and (1×10 −3 M) and temperature (278–293 K). In almost all the cases, equilibrium is established after a 10-min time interval. Lagrergren's first-order rate equation is applied for rate constant determination. From the temperature dependence of the rate constant, energy of activation is calculated. X − ion sorption on chalcopyrite is also studied as a function of pH (8–11) at 293 K in the concentration range (5×10 −5–1×10 −3 M). Sorption of X − is found to increase with pH up to pH 10 and then decreases to pH 11. The data is found to be fitted to the Freundlich equation successfully. The dissolution studies and Fourier transform infrared spectroscopy (FTIR) spectra show that the process responsible for the uptake of xanthate by the chalcopyrite is the formation of cuprous xanthate on the surface of the solid.