The molten slag in smelting reduction with iron bath has peculiar behaviour for its high FeO concentration. Slag foaming is effected by the concentration and reduction rate of FeO, basicity of slag and temperature. Ad...The molten slag in smelting reduction with iron bath has peculiar behaviour for its high FeO concentration. Slag foaming is effected by the concentration and reduction rate of FeO, basicity of slag and temperature. Addition of granulated coke can greatly decrease slag foaming extent in the process of smelting reduction with iron bath. The anti-foaming capacity of granulated coke is the best when the ratio of coke used for coke layer to total coke used in smelting reduction is controlled at about 20%.展开更多
A high-temperature reduction and smelting process was used to recover iron and calcium aluminate slag from high-ferrous bauxite. The effects of w(CaO)/w(SiO_2) ratio, anthracite ratio, and reduction temperature an...A high-temperature reduction and smelting process was used to recover iron and calcium aluminate slag from high-ferrous bauxite. The effects of w(CaO)/w(SiO_2) ratio, anthracite ratio, and reduction temperature and time on the recovery and size of iron nuggets and on the Al_2O_3 grade of the calcium aluminate slag were investigated through thermodynamic calculations and experiments. The optimized process conditions were the bauxite/anthracite/slaked lime weight ratio of 100:16.17:59.37, reduction temperature of 1450°C and reduction time of 20 min. Under these conditions, high-quality iron nuggets and calcium aluminate slag were obtained. The largest size and the highest recovery rate of iron nuggets were 11.42 mm and 92.79wt%, respectively. The calcium aluminate slag mainly comprised Ca_2 SiO_4 and Ca_(12)Al_(14)O_(33), with small amounts of Fe Al_2O_4, CaAl_2O_4, and Ca_2Al_2SiO_7.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
Compost has been used to stabilise lead (Pb) in soil. However, compost contains a high level of dissolved organic matter (DOM) which may make Pb bioavailable in plant and thereby limiting its effectiveness and applica...Compost has been used to stabilise lead (Pb) in soil. However, compost contains a high level of dissolved organic matter (DOM) which may make Pb bioavailable in plant and thereby limiting its effectiveness and application. Addition of biochar to compost can reduce this effect. Rice husk (RH) and Cashew nut shell (CNS) biochars and compost-modified biochars were used in comparison to compost for stabilizing Pb in lead smelting slag (LSS)-contaminated soil (Pb = 18,300 mg/kg) in Nigeria. Efficiency of Pb stabilisation in control and amended soils was assessed using CaCl2 batch leaching experiment and plant performance. In pot experiments, maize plant was grown on the contaminated soil and on soil treated with minimum and optimum doses of the amendments singly and in combination for 6 weeks. Agronomical and chemical parameters of the plants were measured. CaCl2-extractable Pb in the untreated soil was reduced from 60 mg/kg to 0.55 mg/kg in RHB amended soils and non-detectable in other amended soils. RH-biochar/compost increased plant height, number of leaf and leaf area more than the others. Similarly, at minimum rate, it reduced root and shoot Pb by 91% and 86.0% respectively. Compost-modified rice husk biocharstabilised Pb in lead smelting slag contaminated soil reduced Pb plant uptake and improved plant growth. Lead stabilisation through the use of rice husk biochar with compost may be a green method for remediation of lead smelting slag-contaminated soil.展开更多
A two-step leaching method in combination of acid and ethylene diaminetetraacetic acid disodium (EDTA-Na2) was applied to extract metals such as Cd,Cu,Fe,Pb and Zn from a zinc smelting slag. The results show that the ...A two-step leaching method in combination of acid and ethylene diaminetetraacetic acid disodium (EDTA-Na2) was applied to extract metals such as Cd,Cu,Fe,Pb and Zn from a zinc smelting slag. The results show that the extraction rates of Cd,Cu,Fe and Zn in slag reach 88.3%,54.1%,69.6% and 54.7%,respectively,while the extraction rate of Pb is only 0.05% leached with 1.25 mol/L sulfuric acid under the conditions of the ratio of slag to liquid of 100 g/L,65 °C and 120 r/min for 2 h. However,Pb extraction rate from 1.25 mol/L sulfuric acid leached residue reaches as high as 66.5% by using 0.1 mol/L EDTA-Na2 solution. The results indicate that two-step sequential extraction procedure combining 1.25 mol/L sulfuric acid and 0.1 mol/L EDTA-Na2 solution can extensively extract Cd,Cu,Fe,Pb and Zn from zinc smelting slag.展开更多
The geopolymer samples were prepared with smelting waste slag of non-ferrous metal as the raw material and water glass as the activator. The effect of modulus of water glass and water binder ratio on the compressive s...The geopolymer samples were prepared with smelting waste slag of non-ferrous metal as the raw material and water glass as the activator. The effect of modulus of water glass and water binder ratio on the compressive strength was studied. The results show that the strength of the geopolymer activated by water glass with modulus of 1.1 and water binder ratio of 0.28 can maintain an increasing trend in the 90 curing days. Through the analyses with XRD, SEM(EDS), and FTIR, the main reaction products are found to be geopolymer gels, which bond the crystalline minerals to provide strength. The molecular chains of amorphous phase in slag become shorter after depolymerization-polycondensation.展开更多
Effects of FeO content (0, 5%, 10%, and 15% in mass, respectively ) in lab-synthesized smelting redttc- tion slag with iron bath and test temperature (1 450, 1 500, 1550, anti 1 600 ℃ ) on corrosion am,amount and...Effects of FeO content (0, 5%, 10%, and 15% in mass, respectively ) in lab-synthesized smelting redttc- tion slag with iron bath and test temperature (1 450, 1 500, 1550, anti 1 600 ℃ ) on corrosion am,amount and microstructure of fused rebonded magnesia - chrome brick with 26.02 massqc of Cr2O3 were researched by rotary cylinder method. The results show that : ( 1 ) the corro- sion amolult of magnesia -chrome brick by slag without FeO is higher than that by the slag with 5% FeO, and the vorrosion amount increases when FeO content increa- ses from 5% to 15% ; (2) the test temperature is one of the important factors affecting the slag corrosion resist- ance of magnesia - chrome brick, and the corrosion of smelting reduction slag to brick increases with the temperature rising.展开更多
The distribution of titanium,carbon and associated elements(calcium,magnesium,silicon and aluminum)in a smelting process is studied by means of a chemical equilibrium calculation method for multiphase and multicompone...The distribution of titanium,carbon and associated elements(calcium,magnesium,silicon and aluminum)in a smelting process is studied by means of a chemical equilibrium calculation method for multiphase and multicomponent systems,and verified through comparison with production results.In particular,using the coexistence theory for titanium slag structures,the influence of the AIR(anthracite to ilmenite ratio)on the distribution of such elements is analyzed.The results show that the AIR can be adjusted to achieve a selective reduction of oxides in the melt.展开更多
Reduction smelting of the bismuth oxide residue from pressure leaching of bismuth sulfide was investigated in the FeO-SiO_2-CaO ternary slag system.The results show that all the recovery ratios of Bi,Ag,Cu and Pb incr...Reduction smelting of the bismuth oxide residue from pressure leaching of bismuth sulfide was investigated in the FeO-SiO_2-CaO ternary slag system.The results show that all the recovery ratios of Bi,Ag,Cu and Pb increase with the increase of reductive coal proportion,reaction temperature and time,while too much reductive coal would help Fe enter metal phase;CaO/SiO_2and Fe O/SiO_2 of the chosen slag system should be 0.5-0.75 and 1.25-1.75,respectively,for the reason that the slag system has the optimum mobility and is beneficial for the recovery of metals.The corresponding optimum conditions are determined as follows:the added coal proportion is 7%of the leaching residue,CaO/SiO_2 mass ratio in the chosen slag system is 0.5 and FeO-SiO_2 is 1.5,the reaction temperature is 1300°C and the reaction time is 40 min.Under the above conditions,the recovery ratios of Bi,Ag,Cu and Pb are 99.6%,99.8%,97.0%and 97.3%,respectively.展开更多
文摘The molten slag in smelting reduction with iron bath has peculiar behaviour for its high FeO concentration. Slag foaming is effected by the concentration and reduction rate of FeO, basicity of slag and temperature. Addition of granulated coke can greatly decrease slag foaming extent in the process of smelting reduction with iron bath. The anti-foaming capacity of granulated coke is the best when the ratio of coke used for coke layer to total coke used in smelting reduction is controlled at about 20%.
基金financially supported by the International Scientific and Technological Cooperation and Exchange Projects of China (No. 2013DFG50640)
文摘A high-temperature reduction and smelting process was used to recover iron and calcium aluminate slag from high-ferrous bauxite. The effects of w(CaO)/w(SiO_2) ratio, anthracite ratio, and reduction temperature and time on the recovery and size of iron nuggets and on the Al_2O_3 grade of the calcium aluminate slag were investigated through thermodynamic calculations and experiments. The optimized process conditions were the bauxite/anthracite/slaked lime weight ratio of 100:16.17:59.37, reduction temperature of 1450°C and reduction time of 20 min. Under these conditions, high-quality iron nuggets and calcium aluminate slag were obtained. The largest size and the highest recovery rate of iron nuggets were 11.42 mm and 92.79wt%, respectively. The calcium aluminate slag mainly comprised Ca_2 SiO_4 and Ca_(12)Al_(14)O_(33), with small amounts of Fe Al_2O_4, CaAl_2O_4, and Ca_2Al_2SiO_7.
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.
文摘Compost has been used to stabilise lead (Pb) in soil. However, compost contains a high level of dissolved organic matter (DOM) which may make Pb bioavailable in plant and thereby limiting its effectiveness and application. Addition of biochar to compost can reduce this effect. Rice husk (RH) and Cashew nut shell (CNS) biochars and compost-modified biochars were used in comparison to compost for stabilizing Pb in lead smelting slag (LSS)-contaminated soil (Pb = 18,300 mg/kg) in Nigeria. Efficiency of Pb stabilisation in control and amended soils was assessed using CaCl2 batch leaching experiment and plant performance. In pot experiments, maize plant was grown on the contaminated soil and on soil treated with minimum and optimum doses of the amendments singly and in combination for 6 weeks. Agronomical and chemical parameters of the plants were measured. CaCl2-extractable Pb in the untreated soil was reduced from 60 mg/kg to 0.55 mg/kg in RHB amended soils and non-detectable in other amended soils. RH-biochar/compost increased plant height, number of leaf and leaf area more than the others. Similarly, at minimum rate, it reduced root and shoot Pb by 91% and 86.0% respectively. Compost-modified rice husk biocharstabilised Pb in lead smelting slag contaminated soil reduced Pb plant uptake and improved plant growth. Lead stabilisation through the use of rice husk biochar with compost may be a green method for remediation of lead smelting slag-contaminated soil.
基金Project(2011SK3262) supported by Science and Technology Program of Hunan Province,China
文摘A two-step leaching method in combination of acid and ethylene diaminetetraacetic acid disodium (EDTA-Na2) was applied to extract metals such as Cd,Cu,Fe,Pb and Zn from a zinc smelting slag. The results show that the extraction rates of Cd,Cu,Fe and Zn in slag reach 88.3%,54.1%,69.6% and 54.7%,respectively,while the extraction rate of Pb is only 0.05% leached with 1.25 mol/L sulfuric acid under the conditions of the ratio of slag to liquid of 100 g/L,65 °C and 120 r/min for 2 h. However,Pb extraction rate from 1.25 mol/L sulfuric acid leached residue reaches as high as 66.5% by using 0.1 mol/L EDTA-Na2 solution. The results indicate that two-step sequential extraction procedure combining 1.25 mol/L sulfuric acid and 0.1 mol/L EDTA-Na2 solution can extensively extract Cd,Cu,Fe,Pb and Zn from zinc smelting slag.
基金Funded by the Key Project of National Natural Science Foundation of China(No.51472040)
文摘The geopolymer samples were prepared with smelting waste slag of non-ferrous metal as the raw material and water glass as the activator. The effect of modulus of water glass and water binder ratio on the compressive strength was studied. The results show that the strength of the geopolymer activated by water glass with modulus of 1.1 and water binder ratio of 0.28 can maintain an increasing trend in the 90 curing days. Through the analyses with XRD, SEM(EDS), and FTIR, the main reaction products are found to be geopolymer gels, which bond the crystalline minerals to provide strength. The molecular chains of amorphous phase in slag become shorter after depolymerization-polycondensation.
文摘Effects of FeO content (0, 5%, 10%, and 15% in mass, respectively ) in lab-synthesized smelting redttc- tion slag with iron bath and test temperature (1 450, 1 500, 1550, anti 1 600 ℃ ) on corrosion am,amount and microstructure of fused rebonded magnesia - chrome brick with 26.02 massqc of Cr2O3 were researched by rotary cylinder method. The results show that : ( 1 ) the corro- sion amolult of magnesia -chrome brick by slag without FeO is higher than that by the slag with 5% FeO, and the vorrosion amount increases when FeO content increa- ses from 5% to 15% ; (2) the test temperature is one of the important factors affecting the slag corrosion resist- ance of magnesia - chrome brick, and the corrosion of smelting reduction slag to brick increases with the temperature rising.
基金This work was financially supported by“High-Level Youth Talent Special Support Plan”of Kunming City(C202014002)the National Natural Science Foundation of China(51904137)+3 种基金the Applied Basic Research Projects of Yunnan Province(2019FD044)the Open Projects of State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization(CNMRCUKF1905)the Talent Training Project of Kunming University(YJL2102)The authors are grateful to NSFC and“High-Level Talent Special Support Plan”of Kunming City(C201905002).
文摘The distribution of titanium,carbon and associated elements(calcium,magnesium,silicon and aluminum)in a smelting process is studied by means of a chemical equilibrium calculation method for multiphase and multicomponent systems,and verified through comparison with production results.In particular,using the coexistence theory for titanium slag structures,the influence of the AIR(anthracite to ilmenite ratio)on the distribution of such elements is analyzed.The results show that the AIR can be adjusted to achieve a selective reduction of oxides in the melt.
基金Project(134414) supported by the Postdoctoral Funded Program of Central South University,China
文摘Reduction smelting of the bismuth oxide residue from pressure leaching of bismuth sulfide was investigated in the FeO-SiO_2-CaO ternary slag system.The results show that all the recovery ratios of Bi,Ag,Cu and Pb increase with the increase of reductive coal proportion,reaction temperature and time,while too much reductive coal would help Fe enter metal phase;CaO/SiO_2and Fe O/SiO_2 of the chosen slag system should be 0.5-0.75 and 1.25-1.75,respectively,for the reason that the slag system has the optimum mobility and is beneficial for the recovery of metals.The corresponding optimum conditions are determined as follows:the added coal proportion is 7%of the leaching residue,CaO/SiO_2 mass ratio in the chosen slag system is 0.5 and FeO-SiO_2 is 1.5,the reaction temperature is 1300°C and the reaction time is 40 min.Under the above conditions,the recovery ratios of Bi,Ag,Cu and Pb are 99.6%,99.8%,97.0%and 97.3%,respectively.