DEVELOPING A TECHNOLOGY FOR OBTAINING COPPER-IRON ADDITIVES FROM SULFIDE CONCENTRATES BY THE METHOD OF HIGH - TEMPERATURE SELF- PROPAGATING SYNTHESIS

Abstract

The goal of the work is to develop a technology for obtaining copper –iron additives by direct aluminothermic recovery of pre-activated copper concentrate. In order to increase the chemical activity, the copper concentrate was subjected to preliminary mechanochemical activation in a vibromill by the grinding method, and then restored by the aluminothermic method. The combination of mechanochemistry with metal-thermal recovery allowed to carry out the further recovery process in a more efficient and unique way and obtain a modofied copper-iron additive by passing the process of calcination used in traditional metallurgy and therefore the formation of volatile sulfur oxides. The behaviour of minerals present in copper concentrates and the behaviour of this concentrate as a result of mecanical and thermal treatment was studied. The theoretical and termodynamic justification of the mechanical reactions proceeding between iron and copper sulfides and aluminum is performed. The role of the xidant (NaNO3) in the mechanochrmical reactions between iron and copper sulfides and copper sulfides and aluminum is studied. The kinetic patherns of the mechanochemical reactions between iron and copper sulfides and aluminum are revealed. The selection of technical parameters of the aluminothermic recovery process of pre- mechanically activated copper concentrate is made. It is shown that with 60 minutes of vibration grindig of the concentrate and reductant and an aluminum content of 120% theoretically calculated, as well as an excess of CaO and NaNO3 up to 30% according to the content of the mixture, a copper-iron additive can be obtained with a yield of 98 % without traces of aluminum and sulphur.

A structural investigation of the obtained additive is carried out by means of X-ray phase, chemical and metallographical analysis. According to the results of chemical analysis, the additive has the following comosition 47% Fe, 53% Cu without traces of sulfur and aluminum. The metallographic analysis has revealed that the structure of the additive, dependig on the time of mechanochemical activation, is more disptersed and microheterogeneous and is a mechanical mixture of iron and alloy. The Kapan copper concentrate production technology for obtaining copper-iron additives by out-of-furnace aluminothermic recovery is developed and a feasibility study is carried out.