Study On Ozone Oxidation Enhanced Chalcopyrite Leaching And Water Pollution Control

With the continuous development of green metallurgical technology,hydrometallurgy is gradually replacing traditional pyrometallurgy.Prior to the wet leaching stage,metal sulfides are used to beneficiate low-grade minerals.The flotation method is the most common flotation method for sulfide ores,but it can generate a large amount of flotation wastewater,causing harm to the environment and organisms.In addition,the residual flotation agents on the mineral surface can also lead to low metal leaching rates and slow leaching rates.Therefore,the simultaneous removal of organic agents during metal leaching is one of the research focuses of hydrometallurgical efficiency.Xanthate is the most widely used collector in sulfide ore flotation,but its residual amount is large,and traditional oxidative degradation methods are difficult to completely remove.The main advantages of advanced oxidation technology are the ability to generate strong oxidizing hydroxyl radicals,high degradation efficiency,non selectivity in the oxidation process,and no secondary pollution.It has been rapidly developed in the field of wastewater treatment.Therefore,in view of the technical difficulties of difficult degradation of typical flotation reagents（potassium alkyl xanthate）and slow leaching rate of sulfide ores（chalcopyrite）,this paper studied the removal effect,degradation path,and mechanism of alkyl xanthate,explored the removal effect of alkyl xanthate and the leaching rate of chalcopyrite in the common system of flotation reagents and sulfide ores,and ultimately achieved ozone enhanced metal leaching and water pollution control.The specific work content is as follows:（1）The degradation effects of alkyl xanthates based on ozone oxidation systems O₃,O₃/AC,O₃/UV,O₃/H₂O₂,O₃/UV,and O₃/UV/Ti O₂ have been studied.Experiments have shown that the enhanced system can greatly improve the mineralization rate of potassium ethyl xanthate（PEX）,but the removal rate of PEX mainly depends on the amount of O₃ added;To explore the regularity of mineralization rates of four different alkyl xanthates:ethyl xanthate>isopropyl xanthate>butyl xanthate>amyl xanthate.By constructing a QSAR model to correlate the structure and degradation behavior of xanthate,the results confirmed that there was a linear negative correlation between molecular volume（Vm）and ozone degradation rate;The oxidative degradation pathway of PAX was proposed through detection methods such as UV-Vis and GC-MS,which confirmed that the addition of enhanced means UV accelerated the mineralization of intermediate products and promoted the oxidation of refractory pentanol.（2）The research shows that the oxidant used in the wet leaching of ozone chalcopyrite has a significant enhancement effect on metal leaching;The experiments on the conditions for wet leaching of chalcopyrite have shown that the higher the ozone concentration,the lower the solid-liquid ratio,and the higher the leaching efficiency of chalcopyrite.Under the premise of fixed ozone concentration and liquid-solid ratio,the optimal leaching conditions are:temperature 45℃,0.1 mol/L sulfuric acid;Exploring the research on the leaching effect of enhanced ozone oxidation technologies（O₃/H₂O₂and O₃/UV）in advanced oxidation technologies on chalcopyrite ores,experiments have shown that enhanced methods are difficult to achieve synergistic promotion,mainly due to the decomposition of ozone molecules caused by enhanced methods,and the transformed active species cannot have a leaching effect on mineral leaching.Experiments have shown that intensification methods（ball milling activation,ozone nano microbubbles）can greatly shorten the leaching time of chalcopyrite,and clarify the application prospects of ozone nano microbubbles technology in mineral leaching.（3）The study found that the adsorption of PEX by CuFeS₂ in the CuFeS₂ PEX system can be ignored,and that Fe ions can affect the determination of PEX concentration by UV spectrophotometer;Low ore pulp concentrations maintain higher TOC removal rates and higher metal leaching rates in three different oxidation systems;Compared to the CuFeS₂-PEX system treated with O₃/H₂O₂ and O₃/UV oxidation alone,the removal rate of TOC will be significantly improved,and the removal rate of TOC can reach100%;The Cu ion leached from the CuFeS₂-PEX system will form a complex（Cu（PEX）₂）with PEX,which explains the abnormal phenomenon that TOC in the system first decreases rapidly and then increases.