| Copper is widely used in various fields due to its good physical and chemical properties.As the largest copper consumer,China is highly dependent on imports for copper products and raw materials for production.There is an urgent need to develop a new process to broaden the range of copper resources available to ease dependence on imported copper resources.Copper sulfide minerals in nature are often accompanied by enargite.The research on the hydrometallurgical leaching process of high arsenic copper sulfide ore and its application in industrial production can not only improve the utilization rate of domestic copper resources,but also broaden the scope of copper ore import.In this paper,the high arsenic copper sulfide concentrate is taken as the research object,and its main components are intractable pyrite,chalcopyrite and enargite.After summarizing the feasibility of leaching thermodynamics,by comparing the static potentials of the three main minerals and combining with the pri nciple of the primary cell,it is concluded that in the acid system,chalcopyrite and enargite ore are feasible to dissolve.The acid-oxidation leaching method was used to study the leaching of high-arsenic copper sulfide concentrate under ultrasonic-assisted conditions.The best conditions are:temperature 80?C,oxygen 400ml/min,ultrasonic power 320W,stirring speed 200r/min,liquid-solid ratio 8:1,acidity 220g/L.The reaction proceeded for 12h and the copper leaching rate was only 41.96%.It is concluded that the passivation of copper sulfide concentrate may lead to ultrasonic-assisted failure.Then,the leaching of high-arsenic copper sulfide concentrate under atmospheric pressure and oxygen enrichment was studied,The single factor experiments of reaction temperature,liquid-solid ratio and oxygen flux were carried out.The results show that when the temperature is less than 60?C,enargite is preferentially dissolved and the leaching rate of copper is maintained at about 20%.When the temperature exceeds80?C,it can maintain a high copper leaching rate.When the liquid-solid ratio is greater than 15:1,the copper leaching effect is better.When the acidity is in the range of 135-270g/L,the leaching rate of both copper and arsenic increases with the inc rease of acidity.However,when the acidity exceeds 405g/L,both chalcopyrite and enargite have a passivation effect,and enargite is more difficult to dissolve than chalcopyrite.The optimal experimental conditions were obtained:acidity 270g/L,oxygen fl ux2L/min,liquid-solid ratio 20:1,stirring speed 400r/min,and temperature 80?C.The leaching rate of copper exceeded 99%and the leaching rate of arsenic reached 87.29%when reacted for 24h under the best experimental conditions.When the reaction time was extended to 48h,the leaching rate of arsenic reached 98.56%.Use XRD and SEM to detect leaching residue.The test results show that the main components of the leaching slag are Si O2,S0 and Fe S2 under the best reaction conditions.The content of pure sulfur is high,and it has a good crystal form of flocculent or porous mass,which is helpful for separating sulfur products.In the case of poor oxidizing environment,chalcopyrite and enargite are wrapped by pure sulfur,and the leaching process is greatly affected by passivation.Repeated experiments showed that the optimum reaction conditions and leaching rate were reliable.The first return leaching experiment shows that excellent copper leaching rate can be obtained in a shorter time.A copper containing solution of14.62g/l can be obtained by the return leaching,which has the potential of reusing and enriching copper.An experimental study of copper leaching kinetics was carried out.Under the experimental conditions,the activation energy of copper leaching was 35.99k J/mol,and the leaching reaction was in accordance with the mixed control model. |
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