| A company use Basic copper carbonate as a precipitation reagent of arsenic, after the removal of arsenic from copper electrolyte, get the high arsenic basic copper carbonate.The stockpiling of high arsenic copper subcarbonate, causing environmental pollution.There are valuable components for recycling, to achieve the turning waste into treasure, while eliminating the purpose of the environmental pollution material.The process of sulfuric acid leaching high arsenic basic copper carbonate has been experimentally researched.With the method of single factor experiment, the influences of stirring speed, sulfuric acid concentration, reaction temperature, reaction time, on leaching rate of copper and arsenic were investigated.The optimal conditions of sulfuric acid leaching are determined:stirring speed 400 r/min,1 mol/L sulfuric acid concentration, reaction temperature 50℃, reaction time 2.5 h, liquid-solid ratio 7:1.Under the better leaching conditions, copper leaching rate could reach 91.50% and arsenic leaching rate could reach 74.15%.Leaching residue of silver enriched to 1.25 times, can be used as industrial raw materials onthe extraction of silver.By chemical precipitation, while the removal of arsenic, antimony, bismuth in copper sulfate, copper loss rate reached 30%, therefore, halloysite as adsorbent, from sulfuric acid leaching of copper sulfate solution, the adsorption removal of arsenic and antimony bismuth, adsorption removal of arsenic, antimony, bismuth.With the method of single factor experiment, the influences of adsorption time, halloysite concentration, arsenic, antimony, bismuth initial concentration, pH, temperature on adsorption rate of arsenic, antimony and bismuth were investigated.The optimal conditions of halloysite adsorption are determined:adsorption time 4 h, halloysite concentration 6 g/L, reaction time 2.5h, temperature 20℃, pH2.2.Under the best adsorping conditions, arsenic adsorption rate could reach 26.37%, antimony adsorption rate could reach97.37%, bismuth adsorption rate could reach 99.15% and copper loss rate could reach 3.73%.By a single ion adsorption test, found that halloysite adsorption behavior of arsenic and antimony are in line with the Langmuir adsorption isotherm equation, halloysite adsorption behavior of bismuth are in line with the Freunlich adsorption isotherm equation.Results showed that the adsorption process between halloysite on arsenic antimony bismuth single molecular layer and multi molecular layer, belong to the preferential adsorption process.Calculated according to the tired, the equation of halloysite adsorption of arsenic activation energy of 21.49 kJ/mol, show that halloysite for arsenic both physical adsorption and chemical adsorption; adsorption activation energy of bismuth were 77.81 kJ/mol, it show that halloysite adsorption mainly chemical adsorption of bismuth.Thermodynamic studies show that halloysite adsorption arsenic is a spontaneous, endothermic and entropy increase process; halloysite adsorption antimony is a not spontaneous,exothermic and entropy increase process; halloysite adsorption bismuth is a spontaneous, endothermic and entropy increase process; kinetie studies showed that halloysite adsorption of arsenic, antimony, bismuth followed pseudo-second-order model.Indicates that the adsorption of arsenic antimony bismuth halloysite is a complex process of adsorption, including external diffusion, surface adsorption and intraparticle diffusion.The theoretical saturated adsorptive amount of arsenic, antimony, bismuth adsorption were 50.53ã€84.60ã€11.93 mg/g.Ir spectra showed that halloysite adsorption exists complexation of arsenic, bismuth, there exists a ion exchange adsorption of arsenic, antimony bismuth. |
