Leaching of blended slag(BS)was investigated in a microwave oven using hydrogen peroxide and acetic acid.The BSwas a mixture of converter and flash furnace slag containing51%Fe2O3,3.8%CuO,and3.2%ZnO.The important vari...Leaching of blended slag(BS)was investigated in a microwave oven using hydrogen peroxide and acetic acid.The BSwas a mixture of converter and flash furnace slag containing51%Fe2O3,3.8%CuO,and3.2%ZnO.The important variables thatinfluence the metal extraction yield were leaching time,liquid-solid ratio,H2O2and CH3COOH concentrations.The preferredleaching conditions were as follows:CH3COOH concentration4mol/L;H2O2concentration4mol/L;microwave power900W;leaching time30min;liquid-solid ratio25mL/g BS;leaching temperature100°C.Under these conditions,the metal extractions of95%Cu,1.6%Fe,and30%Zn were obtained.The results were compared with the traditional leaching results.It is evident thatmicrowave heating causes a reduction in the leaching time.Also,the extraction yield results indicate that selective leaching of BS canbe achieved under the preferred conditions.The dissolution kinetic of BS in hydrogen peroxide with acetic acid is controlled by ashrinking unreacted core model equation.The apparent activation energy and reaction order were found to be16.64kJ/mol and1.09,respectively.展开更多
The addition of NaCl in the ammonium persulfate-APS(as an oxidant)leaching was investigated.APS has some advantages compared with conventional oxidants and its standard redox potential(E°)is2.0V.Effect of six par...The addition of NaCl in the ammonium persulfate-APS(as an oxidant)leaching was investigated.APS has some advantages compared with conventional oxidants and its standard redox potential(E°)is2.0V.Effect of six parameters such as NaCl concentration,APS concentration,temperature,time,liquid–solid ration(L/S),and stirring speed on the leaching behavior was studied.Results showed that metals extraction increased with increasing of NaCl concentration,APS concentration,leaching temperature(up to333K),and L/S ratio.During oxidative leaching of sulfide minerals,the occurrence of elemental sulfur layer on particle surface is known as primary problem that causes low metal extraction.According to the results,the passivation effect of sulfur layer and low dissolution problems can be eliminated in the presence of chloride ions.Copper and iron extraction yields were obtained as75%and80%,respectively under leaching conditions as follows:APS concentration250g/L;NaCl concentration150g/L;time180min;temperature333K;stirring speed400r/min;and L/S250mL/g.展开更多
The leaching behavior of a copper flotation concentrate was investigated using ammonium persulfate （APS） in an autoclave systee. The decomposition products of APS, active oxygen, and acidic medium were used to extra...The leaching behavior of a copper flotation concentrate was investigated using ammonium persulfate （APS） in an autoclave systee. The decomposition products of APS, active oxygen, and acidic medium were used to extract metals from the concentrate. Leaching experiments were performed to compare the availability of APS as an oxidizing agent for leaching of the concentrate under atmospheric conditions and in an autoclave system. Leaching temperature and APS concentration were found to be important parameters in both leaching systems. Atmospheric leaching studies showed that the metal extractions increased with the increase in APS concentration and temperature （up to 333 K）. A similar tendency was determined in the autoclave studies up to 423 K. It was also determined that the metal extractions decreased at temperatures above 423 K due to the passivation of the particle surface by molten elemental sulfur. The results showed that higher copper extractions could be achieved using an autoclave system.展开更多
文摘Leaching of blended slag(BS)was investigated in a microwave oven using hydrogen peroxide and acetic acid.The BSwas a mixture of converter and flash furnace slag containing51%Fe2O3,3.8%CuO,and3.2%ZnO.The important variables thatinfluence the metal extraction yield were leaching time,liquid-solid ratio,H2O2and CH3COOH concentrations.The preferredleaching conditions were as follows:CH3COOH concentration4mol/L;H2O2concentration4mol/L;microwave power900W;leaching time30min;liquid-solid ratio25mL/g BS;leaching temperature100°C.Under these conditions,the metal extractions of95%Cu,1.6%Fe,and30%Zn were obtained.The results were compared with the traditional leaching results.It is evident thatmicrowave heating causes a reduction in the leaching time.Also,the extraction yield results indicate that selective leaching of BS canbe achieved under the preferred conditions.The dissolution kinetic of BS in hydrogen peroxide with acetic acid is controlled by ashrinking unreacted core model equation.The apparent activation energy and reaction order were found to be16.64kJ/mol and1.09,respectively.
基金supported by the FUBAP(Firat University scientific research projects)under the project No:MF.12.32
文摘The addition of NaCl in the ammonium persulfate-APS(as an oxidant)leaching was investigated.APS has some advantages compared with conventional oxidants and its standard redox potential(E°)is2.0V.Effect of six parameters such as NaCl concentration,APS concentration,temperature,time,liquid–solid ration(L/S),and stirring speed on the leaching behavior was studied.Results showed that metals extraction increased with increasing of NaCl concentration,APS concentration,leaching temperature(up to333K),and L/S ratio.During oxidative leaching of sulfide minerals,the occurrence of elemental sulfur layer on particle surface is known as primary problem that causes low metal extraction.According to the results,the passivation effect of sulfur layer and low dissolution problems can be eliminated in the presence of chloride ions.Copper and iron extraction yields were obtained as75%and80%,respectively under leaching conditions as follows:APS concentration250g/L;NaCl concentration150g/L;time180min;temperature333K;stirring speed400r/min;and L/S250mL/g.
基金financially supported by the Scientific and Technological Research Council of Turkey (TUBITAK,No.106M177)
文摘The leaching behavior of a copper flotation concentrate was investigated using ammonium persulfate （APS） in an autoclave systee. The decomposition products of APS, active oxygen, and acidic medium were used to extract metals from the concentrate. Leaching experiments were performed to compare the availability of APS as an oxidizing agent for leaching of the concentrate under atmospheric conditions and in an autoclave system. Leaching temperature and APS concentration were found to be important parameters in both leaching systems. Atmospheric leaching studies showed that the metal extractions increased with the increase in APS concentration and temperature （up to 333 K）. A similar tendency was determined in the autoclave studies up to 423 K. It was also determined that the metal extractions decreased at temperatures above 423 K due to the passivation of the particle surface by molten elemental sulfur. The results showed that higher copper extractions could be achieved using an autoclave system.
