بررسي پارامترهاي موثر در ليچينگ كنسانتره اسفالريت

Studies of the Effective Parameters on Leaching of Sphalerite Concentrate

A set of experimental tests have been conducted to study the method of direct dissolution of zinc sulphide concentrate using gas-liquid mass transfer equipment. In this process, oxygen plays the role of an oxidant and iron is the catalyst. The amount of oxygen in the solution has an important effect on kinetics of the whole process. The formation of elemental sulphur layer on the surface of the concentrate follows the shrinking core model. In this article, the effect of parameters such as the rotational mixing speed and the amount of oxygen consumption is studied. Moreover, the effects of concentrate content on the electrolyte concentration, temperature and pressure on the mass transfer coefficient are analyzed. As the experiments prove, when sulphuric acid concentration and the liquid temperature rise, the dissolution of oxygen decreases and as a result the mass transfer coefficient decreases. An increase in hydrostatic pressure from 200 to 800 Pascal does not affect the mass transfer coefficient. In most circumstances, the mass transfer coefficient rises as the rate of gas flow and the rotational mixing speed increase. Experimental results show that a rise in the zinc concentrate content increases the oxygen consumption amount.