Red mud is a solid waste discharged in the process of alumina production,and how to realize the efficient recovery of its iron is an urgent problem to be solved.In this study,the iron extraction test and mechanism stu...Red mud is a solid waste discharged in the process of alumina production,and how to realize the efficient recovery of its iron is an urgent problem to be solved.In this study,the iron extraction test and mechanism study of high iron red mud were carried out under the coupling conditions of multiple physical field(microwave field,gas-solid flow field and temperature field)with biomass as the reducing agent.The test results showed that under the optimal conditions,an iron concentrate with a yield of 78.4%,an iron grade of 59.23%,and a recovery rate of 86.65%was obtained.The analyses of XRD,XPS,TEM,and SEM-EDS showed that during the roasting process,the hematite in the high-iron red mud was completely converted to magnetite,and the biomass produced the reductant that provided the magnetization reaction;A large number of cracks and pores appeared in the surface of the hematite reduction product particles,which helped to induce iron minerals to undergo effective mineral phase transformation.The above study provides ideas for the phase transformation and efficient recovery of iron minerals in red mud.展开更多
The chemical and mineral compositions of bauxite recovered from the Severoonezhsk Bauxite Mine(Arkhangelsk region,Russia)were studied by XRD,ICP-OES,TG/DSC,SEM,TEM,and Mössbauer spectroscopy.The iron-containing m...The chemical and mineral compositions of bauxite recovered from the Severoonezhsk Bauxite Mine(Arkhangelsk region,Russia)were studied by XRD,ICP-OES,TG/DSC,SEM,TEM,and Mössbauer spectroscopy.The iron-containing minerals of the bauxites were found to comprise alumogoethite(α-Fe_(1−x)Al_(x)OOH),alumohematite(α-(Fe_(1−x)Al_(x))_(2)O_(3)),alumoakaganeite(β-Fe_(1−x)Al_(x)O(OH,Cl)),and chromite(FeCr_(2)O_(4)).The efficiency of Fe extraction from the bauxite by HCl leaching was 82.5%at 100℃,HCl concentration of 10%,solid/liquid ratio of 1:10,and the process duration of 60 min,with aluminum loss from the bauxites below 4.5%of the total Al contents in the bauxite.Analysis of the kinetics of the iron leaching process proved diffusion to be the limiting stage of the process at 90−100℃.Bauxite residue after leaching presented traces of α-Fe_(1−x)Al_(x)OOH and β-Fe_(1−x)Al_(x)O(OH,Cl),and most of the iron content was in the FeCr_(2)O_(4).In bauxite residue after HCl leaching,in addition to iron oxide,the contents of chromium and calcium oxides significantly decreased.The iron chloride liquor after leaching contained the rare earth elements(REE)of 6.8 mg/L Sc,4.1 mg/L Ce and 2.3 mg/L Ga.展开更多
A new bath smelting process was proposed to recover iron for solid wastes reduction.99.79%of iron metallization,99.61%of iron recovery,pig iron with93.58%Fe,0.021%S,0.11%P,1.38%C,0.22%Si,0.01%Pb and0.031%Zn were achie...A new bath smelting process was proposed to recover iron for solid wastes reduction.99.79%of iron metallization,99.61%of iron recovery,pig iron with93.58%Fe,0.021%S,0.11%P,1.38%C,0.22%Si,0.01%Pb and0.031%Zn were achievedafter the wastes were smelted at1575°C for20min under C/Fe molar ratio of1.6and basicity of1.2.The produced pig iron could beused in steel-making.This study provides a way for recycling iron from smelting slag and hydrometallurgical residue.展开更多
The extraction and stripping of scandium from its sulfate solutions by isopropyl phosphonic acid mono (1-hexyl-4-ethyl) octyl ester (PT-2, HL) diluted with n-hexane are reported. A high efficiency of separation betwee...The extraction and stripping of scandium from its sulfate solutions by isopropyl phosphonic acid mono (1-hexyl-4-ethyl) octyl ester (PT-2, HL) diluted with n-hexane are reported. A high efficiency of separation between scandium, iron and lutetium can be achieved by controlling aqueous acidity. Different mechanisms of Sc3+ with PT-2 in various acid range have been proposed.At lower aqueous acidity, it is a cation exchange reaction, while at higher acidity. a solvation reaction was ascertained. Its IR and NMR spectra have been discussed. The effect of temperature on extraction of Sc3+ was observed and thermodynamic functions were calculated.展开更多
In view of the difficulty of extracting iron from Bayer red mud,a new idea of adding laterite nickel ore into red mud was proposed to prepare a high value-added product.Toward this,the influences of laterite nickel or...In view of the difficulty of extracting iron from Bayer red mud,a new idea of adding laterite nickel ore into red mud was proposed to prepare a high value-added product.Toward this,the influences of laterite nickel ore on thermodynamic reaction,slagging and smelting reduction of extracting iron from red mud were studied.The results indicated that the product of extracting iron from red mud(R100)was changed with the addition of laterite nickel ore(R70L30).The slag of R100 was strongly basic,while the R70L30 was weakly acidic with composition closer to the ideal blast furnace slag.The metal recovery of R100 was 75.16%and that of R70L30 was 94.05%.At the same temperature,the slag viscosity of R70L30 was significantly lower than that of R100,which proved that laterite nickel ore can adjust the basicity,reduce melting point of slag and improve metal recovery.Because Fe,Ni and Cr in red mud and laterite nickel ore can be reduced sufficiently,a low Ni–Cr alloy cast iron can be directly prepared.展开更多
基金Project(MMCS2023OF02)supported by the Open Foundation of State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures,ChinaProject(AA23073018)supported by the Guangxi Science and Technology,ChinaProject(2024M751861)supported by the China Postdoctoral Science Foundation。
文摘Red mud is a solid waste discharged in the process of alumina production,and how to realize the efficient recovery of its iron is an urgent problem to be solved.In this study,the iron extraction test and mechanism study of high iron red mud were carried out under the coupling conditions of multiple physical field(microwave field,gas-solid flow field and temperature field)with biomass as the reducing agent.The test results showed that under the optimal conditions,an iron concentrate with a yield of 78.4%,an iron grade of 59.23%,and a recovery rate of 86.65%was obtained.The analyses of XRD,XPS,TEM,and SEM-EDS showed that during the roasting process,the hematite in the high-iron red mud was completely converted to magnetite,and the biomass produced the reductant that provided the magnetization reaction;A large number of cracks and pores appeared in the surface of the hematite reduction product particles,which helped to induce iron minerals to undergo effective mineral phase transformation.The above study provides ideas for the phase transformation and efficient recovery of iron minerals in red mud.
基金Ministry of Science and Higher Education of the Russian Federation(scientific topic No.0137-2019-0023).
文摘The chemical and mineral compositions of bauxite recovered from the Severoonezhsk Bauxite Mine(Arkhangelsk region,Russia)were studied by XRD,ICP-OES,TG/DSC,SEM,TEM,and Mössbauer spectroscopy.The iron-containing minerals of the bauxites were found to comprise alumogoethite(α-Fe_(1−x)Al_(x)OOH),alumohematite(α-(Fe_(1−x)Al_(x))_(2)O_(3)),alumoakaganeite(β-Fe_(1−x)Al_(x)O(OH,Cl)),and chromite(FeCr_(2)O_(4)).The efficiency of Fe extraction from the bauxite by HCl leaching was 82.5%at 100℃,HCl concentration of 10%,solid/liquid ratio of 1:10,and the process duration of 60 min,with aluminum loss from the bauxites below 4.5%of the total Al contents in the bauxite.Analysis of the kinetics of the iron leaching process proved diffusion to be the limiting stage of the process at 90−100℃.Bauxite residue after leaching presented traces of α-Fe_(1−x)Al_(x)OOH and β-Fe_(1−x)Al_(x)O(OH,Cl),and most of the iron content was in the FeCr_(2)O_(4).In bauxite residue after HCl leaching,in addition to iron oxide,the contents of chromium and calcium oxides significantly decreased.The iron chloride liquor after leaching contained the rare earth elements(REE)of 6.8 mg/L Sc,4.1 mg/L Ce and 2.3 mg/L Ga.
基金Project(51574295) supported by the National Natural Science Foundation of ChinaProject(2014FJ1011) supported by the Key Project of Science and Technology of Hunan Province,China+1 种基金Project(2012GS430201) supported by the Science and Technology Program for Public Wellbeing,ChinaProject supported by the Co-Innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources,China
文摘A new bath smelting process was proposed to recover iron for solid wastes reduction.99.79%of iron metallization,99.61%of iron recovery,pig iron with93.58%Fe,0.021%S,0.11%P,1.38%C,0.22%Si,0.01%Pb and0.031%Zn were achievedafter the wastes were smelted at1575°C for20min under C/Fe molar ratio of1.6and basicity of1.2.The produced pig iron could beused in steel-making.This study provides a way for recycling iron from smelting slag and hydrometallurgical residue.
文摘The extraction and stripping of scandium from its sulfate solutions by isopropyl phosphonic acid mono (1-hexyl-4-ethyl) octyl ester (PT-2, HL) diluted with n-hexane are reported. A high efficiency of separation between scandium, iron and lutetium can be achieved by controlling aqueous acidity. Different mechanisms of Sc3+ with PT-2 in various acid range have been proposed.At lower aqueous acidity, it is a cation exchange reaction, while at higher acidity. a solvation reaction was ascertained. Its IR and NMR spectra have been discussed. The effect of temperature on extraction of Sc3+ was observed and thermodynamic functions were calculated.
基金financially supported by the Center of Ecological Collaborative Innovation for Aluminum Industry in Guangxi and the Special Project for Innovation-driven Development of Guangxi(No.AA17202001).
文摘In view of the difficulty of extracting iron from Bayer red mud,a new idea of adding laterite nickel ore into red mud was proposed to prepare a high value-added product.Toward this,the influences of laterite nickel ore on thermodynamic reaction,slagging and smelting reduction of extracting iron from red mud were studied.The results indicated that the product of extracting iron from red mud(R100)was changed with the addition of laterite nickel ore(R70L30).The slag of R100 was strongly basic,while the R70L30 was weakly acidic with composition closer to the ideal blast furnace slag.The metal recovery of R100 was 75.16%and that of R70L30 was 94.05%.At the same temperature,the slag viscosity of R70L30 was significantly lower than that of R100,which proved that laterite nickel ore can adjust the basicity,reduce melting point of slag and improve metal recovery.Because Fe,Ni and Cr in red mud and laterite nickel ore can be reduced sufficiently,a low Ni–Cr alloy cast iron can be directly prepared.
