To recover metal from copper slags,a new process involving two steps of oxidative desulfurization followed by smelting reduction was proposed in which one hazardous waste(waste cathode carbon)was used to treat another...To recover metal from copper slags,a new process involving two steps of oxidative desulfurization followed by smelting reduction was proposed in which one hazardous waste(waste cathode carbon)was used to treat another(copper slags).The waste cathode carbon is used not only as a reducing agent but also as a fluxing agent to decrease slag melting point.Upon holding for 60 min in air atmosphere first and then smelting with 14.4 wt%waste cathode carbon and 25 wt%CaO for 180 min in high purity Ar atmosphere at 1450℃,the recovery rates of Cu and Fe reach 95.89%and 94.64%,respectively,and meanwhile greater than 90%of the fluoride from waste cathode carbon is transferred into the final slag as CaF_(2) and Ca_(2)Si_(2)F_(2)O_(7),which makes the content of soluble F in the slag meet the national emission standard.Besides,the sulphur content in the obtained Fe-Cu alloy is low to 0.03 wt%.展开更多
In order to reasonably utilize the iron resources of copper slags, the smelting chlorination process was used to remove copper from copper slags. Higher holding temperature and O2 flow rate are beneficial to increasin...In order to reasonably utilize the iron resources of copper slags, the smelting chlorination process was used to remove copper from copper slags. Higher holding temperature and O2 flow rate are beneficial to increasing copper removal rate. However,the Cu2O mode is formed by the reaction of surplus O2 and CuCl with O2 flow rate increasing over 0.4 L/min, causing CuCl volatilization rate and copper removal rate to decrease. The resulting copper removal rate of 84.34% is obtained under the optimum conditions of holding temperature of 1573 K, residence time of 10 min, Ca Cl2 addition amount of 0.1(mass ratio of CaCl2 and the copper slag) and oxygen flow rate of 0.4 L/min. The efficient removal of copper from copper slags through chlorination is feasible.展开更多
An optimized selective sequential extraction(SSE)procedure was developed to assess the arsenic(As)partitioning in copper slag.The potential As species in copper slag are partitioned into the readily soluble As,dissolv...An optimized selective sequential extraction(SSE)procedure was developed to assess the arsenic(As)partitioning in copper slag.The potential As species in copper slag are partitioned into the readily soluble As,dissolvable arsenates,sparingly soluble arsenates,As residing in sulfides,arsenopyrite and metal As,as well as As incorporated into glassy silicates.The inductively coupled plasma atomic emission spectrometry(ICP-AES),scanning electronic microscopy(SEM),transmission electron microscope(TEM),X-ray diffractometry(XRD)and Fourier transform infrared spectroscopy(FTIR)were used to characterize the leachates and residues produced from the operation scheme.The selectivity and recovery of extractants were evaluated through single-phase extraction procedures.Partitioning data of As in slag samples show good agreement with the reported works and the total As recovery of each operation is over 90%.This suggests that the optimized SEE scheme can be reliably employed for As partitioning in As-bearing byproducts from copper smelting.展开更多
基金Project(U1602272)supported by the National Natural Science Foundation of China。
文摘To recover metal from copper slags,a new process involving two steps of oxidative desulfurization followed by smelting reduction was proposed in which one hazardous waste(waste cathode carbon)was used to treat another(copper slags).The waste cathode carbon is used not only as a reducing agent but also as a fluxing agent to decrease slag melting point.Upon holding for 60 min in air atmosphere first and then smelting with 14.4 wt%waste cathode carbon and 25 wt%CaO for 180 min in high purity Ar atmosphere at 1450℃,the recovery rates of Cu and Fe reach 95.89%and 94.64%,respectively,and meanwhile greater than 90%of the fluoride from waste cathode carbon is transferred into the final slag as CaF_(2) and Ca_(2)Si_(2)F_(2)O_(7),which makes the content of soluble F in the slag meet the national emission standard.Besides,the sulphur content in the obtained Fe-Cu alloy is low to 0.03 wt%.
基金Project(51204082)supported by the National Natural Science Foundation of ChinaProject(KKZ3201252011)supported by Talent Cultivation Project of Kunming University of Science and Technology,China
文摘In order to reasonably utilize the iron resources of copper slags, the smelting chlorination process was used to remove copper from copper slags. Higher holding temperature and O2 flow rate are beneficial to increasing copper removal rate. However,the Cu2O mode is formed by the reaction of surplus O2 and CuCl with O2 flow rate increasing over 0.4 L/min, causing CuCl volatilization rate and copper removal rate to decrease. The resulting copper removal rate of 84.34% is obtained under the optimum conditions of holding temperature of 1573 K, residence time of 10 min, Ca Cl2 addition amount of 0.1(mass ratio of CaCl2 and the copper slag) and oxygen flow rate of 0.4 L/min. The efficient removal of copper from copper slags through chlorination is feasible.
基金Projects(51874257,51374185,51801183)supported by the National Natural Science Foundation of China。
文摘An optimized selective sequential extraction(SSE)procedure was developed to assess the arsenic(As)partitioning in copper slag.The potential As species in copper slag are partitioned into the readily soluble As,dissolvable arsenates,sparingly soluble arsenates,As residing in sulfides,arsenopyrite and metal As,as well as As incorporated into glassy silicates.The inductively coupled plasma atomic emission spectrometry(ICP-AES),scanning electronic microscopy(SEM),transmission electron microscope(TEM),X-ray diffractometry(XRD)and Fourier transform infrared spectroscopy(FTIR)were used to characterize the leachates and residues produced from the operation scheme.The selectivity and recovery of extractants were evaluated through single-phase extraction procedures.Partitioning data of As in slag samples show good agreement with the reported works and the total As recovery of each operation is over 90%.This suggests that the optimized SEE scheme can be reliably employed for As partitioning in As-bearing byproducts from copper smelting.
