Theoretical Study On Thermally Activated Sulfidation-flotation Of Typical Copper Oxide Minerals

China is a big country of copper consumption and has a high dependence on foreign copper resources for a long time.With the continuous development and utilization of copper resources for a long time,copper sulfide ore resources are drying up,and the recovery and utilization of copper oxide ores,especially complex refractory copper oxide ores,are becoming more and more important.Malachite and chrysocolla are two typical copper oxide ores,and their development and utilization have always been the research focus of mineral processing workers.As a typical copper oxide mineral with industrial value,the main recovery method of malachite at present is sulfide-xanthate flotation method.However,this method still has some shortcomings,such as low sulfide efficiency,strict requirements on the dosage of sulfide agent,and large consumption of xanthate.Chrysocolla is difficult to be sulfided flotation,so its efficient recovery has become a long-term problem.In order to realize the high-efficiency recovery of copper oxide minerals,this paper puts forward the basic theory of thermal activation sulfuration-flotation of typical copper oxide minerals malachite and chrysocolla,and explores the thermal activation transformation mechanism of two kinds of copper oxide ores with sulfur and pyrite as sulfuration agents.The refractory copper oxide minerals are transformed into copper sulfide components with better floatability,and the traditional flotation recovery method of sulfide ore is used to enrich and recover them.The main research contents and results are as follows:Through thermodynamic calculation of thermal activation sulfuration process,the sulfuration transformation mechanism of two kinds of copper oxide minerals was explored,and the favorable transformation conditions in the process of thermal activation sulfuration of two kinds of copper oxide minerals were found out,which confirmed the feasibility of thermal activation sulfuration transformation of two kinds of copper oxide minerals under specific reaction conditions.The thermal activation sulfuration-flotation tests of malachite and chrysocolla with sulfur and pyrite as sulfuration agents were carried out.The experimental results show that the roasting temperature and the amount of sulfuration agent have a crucial influence on the flotation behavior of thermally activated sulfide products.Sulfur and pyrite were used as sulfuration agents for malachite and chrysocolla,respectively.The thermal activation sulfuration-flotation test was carried out to explore the flotation response of thermal activation sulfuration products under different sulfuration agent dosage and flotation conditions,and the optimal experimental conditions were determined.The thermal activation sulfuration and efficient recovery of malachite and chrysocolla were effectively realized.Under the optimal conditions,the flotation recovery rate of products can reach about 90%.Based on the results of single mineral flotation test and combined with XRD,XPS,EPMA,UV spectrophotometer and other detection and analysis methods,the transformation mechanism of malachite and chrysocolla,typical copper oxide minerals,in the thermal activation and sulfuration process with sulfur and pyrite as sulfuration agents was explored.The X-ray photoelectron spectroscopy study showed that after thermal activation and sulfuration of malachite and chrysocolla,the concentration of O atoms on the product surface decreased significantly,while the concentration of S atoms increased significantly.EPMA studies show that compared with the blank roasting of malachite without adding sulfuration agent,the addition of sulfuration agent can on the one hand transform the copper oxide component into the copper sulfide component to improve the flotation response,and on the other hand,the sulfide film generated on the surface of the product can reduce the pores on the surface of the roasting product,which is beneficial to the flotation operation.It indicated that the addition of sulfuration agent could generate sulfide film on the product surface and even completely transform the product into corresponding sulfide,which was conducive to subsequent flotation recovery.The results of adsorption capacity showed that the increase of sulfur content in the thermal activation and sulfuration process of malachite was beneficial to the adsorption of butyl xanthate on the sulfuration product.When pyrite is used as sulfur source,the excessive amount of pyrite is not conducive to the adsorption of sulfide products on collectors.Combined with XPS and thermodynamic calculation analysis,it can be attributed to a large number of iron oxides generated on the surface of the product.For the thermally activated sulfide products of malachite,the sulfide products within the range of n S₂:n Cu Si O₃·2H₂O=0.4-1showed good adsorption effect on butyl xanthate.The above conclusions confirm the reliability of thermodynamic calculation and single mineral flotation test results.