Flotation chemistry of enargite and chalcopyrite using potassium amyl xanthate and depressants

Efficient separation of enargite from other sulphide minerals is of great importance for the metallurgical performance of flotation processes. This research was undertaken to study the flotation chemistry of enargite in order to investigate the possible selective depression of this mineral from chalcopyrite in copper concentrates. To achieve this aim adsorption and flotation characteristics of enargite and chalcopyrite using potassium amyl xanthate (PAX) have been investigated. The effects of sodium cyanide, sodium sulphide, potassium permanganate and aeration (air oxidation) as depressants on the adsorption density of xanthate and floatability were studied.; It was found that the adsorption process on the enargite surface is independent of pH in the range of 6 to 9 but decreases at higher pH values. The reaction of xanthate with the oxidation products on the surface of enargite through an ion-exchange process is considered to be the major adsorption mechanism responsible for the xanthate flotation of enargite. The surface species responsible for flotation of enargite based on electrochemical model theory and electronic structure of the solid adsorbent and infrared studies was determined to be cuprous xanthate. Investigation of the effect of sodium cyanide showed that cyanide decreased the adsorption density and the adsorbed xanthate was rapidly removed from the enargite surface. Sodium sulphide had less depression effect than cyanide on enargite. In the presence of oxidants the recovery of enargite decreased remarkably.; The effects of NaCN and KMnO{dollar}sb4{dollar} on chalcopyrite showed that the adsorption density and flotation recovery decreased with increasing concentrations of these ions. Sodium sulphide had the strongest depression effect on chalcopyrite.; Depression of enargite from a bulk chalcopyrite-enargite concentrate at pH 9 was achieved through the use of appropriate concentrations of sodium cyanide and potassium permanganate. Alternately, chalcopyrite was depressed by application of sodium sulphide while floating enargite.; Eventually, efforts were made to develop a new and more selective depressant for enargite without any impact on the environment. The separation of enargite and chalcopyrite was achieved through the application of a newly developed depressant for enargite by using a mixture of Magnesium Chloride, Ammonium Chloride and Ammonium Hydroxide (MAA).