A study on the melting and viscosity properties of the chromium-containing high-titanium melting slag(CaO–SiO2–MgO–Al2O3–TiO2–Cr2O3) with TiO2 contents ranging from 38.63 wt% to 42.63 wt% was conducted. The melti...A study on the melting and viscosity properties of the chromium-containing high-titanium melting slag(CaO–SiO2–MgO–Al2O3–TiO2–Cr2O3) with TiO2 contents ranging from 38.63 wt% to 42.63 wt% was conducted. The melting properties were investigated with a meltingpoint apparatus, and viscosity was measured using the rotating cylinder method. The FactSage 7.1 software and X-ray diffraction, in combination with scanning electron microscopy–energy-dispersive spectroscopy(SEM–EDS), were used to characterize the phase equilibrium and microstructure of chromium-containing high-titanium melting slags. The results indicated that an increase in the TiO2 content led to a decrease in the viscosity of the chromium-containing high-titanium melting slag. In addition, the softening temperature, hemispheric temperature, and flowing temperature decreased with increasing TiO2 content. The amount of crystallized anosovite and sphene phases gradually increased with increasing TiO2 content, whereas the amount of perovskite phase decreased. SEM observations revealed that the distribution of the anosovite phase was dominantly influenced by TiO2.展开更多
Based on the coexistence theory of slag melt structure and Butler’s equation,a new calculation model has been proposed for the calculation of surface tension of slag melt.This model establishes a specific correlation...Based on the coexistence theory of slag melt structure and Butler’s equation,a new calculation model has been proposed for the calculation of surface tension of slag melt.This model establishes a specific correlation between surface tension and mass action concentrations(activities) in the melt and on its surface on the basis of inner and surficial structures of slag melt.Calculated surface tensions of CaO-SiOand MnO-SiOslag melts are consistent with those measured.Furthermore,iso-surface tension lines of CaO-MnO-SiOslag melt have also been calculated.展开更多
The steel slag in the decarburization converter is treated by the little water-spreading ( LWS ) and the heat-stewed ( HS ) methods , which is used as the furnace burden of the dephosphorization converter.The slag...The steel slag in the decarburization converter is treated by the little water-spreading ( LWS ) and the heat-stewed ( HS ) methods , which is used as the furnace burden of the dephosphorization converter.The slag characteristics by the LWS and the HS methods and its application effects as the furnace burden are researched.The results show the moisture content in the HS slag is higher than that of the LWS slag.There is higher total iron content in the HS and the LWS slags and almost same melting point.The dicalcium silicate content in the LWS slag is higher than that in the HS slag.The tricalcium silicate in the LWS slag is lower than that in the HS slag.There are a lot of calcium ferrite in the LWS and the HS slags , which is beneficial to dephosphorization and slag melting.The LWS and the HS slags are added to dephosphorization converter each charge by 3or 6t.The results show that the saving lime is 0.7-1.0tfor each charge.The petrographic constitute of final slag for the dephosphorization converter by adding the LWS and the HS slags is dicalcium silicate , RO phase and glass phase.There are a little calcium ferrite phase in the LWS slag , which is helpful to dephosphorization.So there are better dephosphorization effects for the LWS and HS slags.展开更多
The pre-reduced Bayan Obo ferroniobium(FeNb)ore concentrate block was taken as raw materials for studying the physical properties of niobium-enriched slag and changes in niobium recovery rate.In addition,the dephosp...The pre-reduced Bayan Obo ferroniobium(FeNb)ore concentrate block was taken as raw materials for studying the physical properties of niobium-enriched slag and changes in niobium recovery rate.In addition,the dephosphorization rate of the slag under different melting-separation conditions was investigated using the melting-separation test.The research results demonstrate that(i)the niobium recovery rate and dephosphorization rate of the slag decrease with the increase in melting-separation temperature;(ii)the niobium recovery rate of the slag initially increases and then decreases with increase in basicity and time;and(iii)the dephosphorization rate of the slag increases with the increase in basicity and time.When the test was performed under the conditions of basicity of 0.6-0.7,time of 7-10min,and temperature of 1400-1450°C,the niobium recovery rate and dephosphorization rate are over 96%and 95%,respectively.By scanning electron microscopy,it is observed that niobium mainly exists in the form of calcium and titanium silicate within the slag phase,with uneven distribution.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51904066)the Fundamental Research Funds for the Central Universities,China(No.N182503032)+1 种基金the Postdoctoral Foundation of Northeastern University,China(No.20190201)the Postdoctoral International Exchange Program,China(Dispatch Project,20190075)
文摘A study on the melting and viscosity properties of the chromium-containing high-titanium melting slag(CaO–SiO2–MgO–Al2O3–TiO2–Cr2O3) with TiO2 contents ranging from 38.63 wt% to 42.63 wt% was conducted. The melting properties were investigated with a meltingpoint apparatus, and viscosity was measured using the rotating cylinder method. The FactSage 7.1 software and X-ray diffraction, in combination with scanning electron microscopy–energy-dispersive spectroscopy(SEM–EDS), were used to characterize the phase equilibrium and microstructure of chromium-containing high-titanium melting slags. The results indicated that an increase in the TiO2 content led to a decrease in the viscosity of the chromium-containing high-titanium melting slag. In addition, the softening temperature, hemispheric temperature, and flowing temperature decreased with increasing TiO2 content. The amount of crystallized anosovite and sphene phases gradually increased with increasing TiO2 content, whereas the amount of perovskite phase decreased. SEM observations revealed that the distribution of the anosovite phase was dominantly influenced by TiO2.
文摘Based on the coexistence theory of slag melt structure and Butler’s equation,a new calculation model has been proposed for the calculation of surface tension of slag melt.This model establishes a specific correlation between surface tension and mass action concentrations(activities) in the melt and on its surface on the basis of inner and surficial structures of slag melt.Calculated surface tensions of CaO-SiOand MnO-SiOslag melts are consistent with those measured.Furthermore,iso-surface tension lines of CaO-MnO-SiOslag melt have also been calculated.
基金Item Sponsored by National Key Technology Research and Development Program in 11th Five-Year Plan of China ( 2006BAE03A00 )
文摘The steel slag in the decarburization converter is treated by the little water-spreading ( LWS ) and the heat-stewed ( HS ) methods , which is used as the furnace burden of the dephosphorization converter.The slag characteristics by the LWS and the HS methods and its application effects as the furnace burden are researched.The results show the moisture content in the HS slag is higher than that of the LWS slag.There is higher total iron content in the HS and the LWS slags and almost same melting point.The dicalcium silicate content in the LWS slag is higher than that in the HS slag.The tricalcium silicate in the LWS slag is lower than that in the HS slag.There are a lot of calcium ferrite in the LWS and the HS slags , which is beneficial to dephosphorization and slag melting.The LWS and the HS slags are added to dephosphorization converter each charge by 3or 6t.The results show that the saving lime is 0.7-1.0tfor each charge.The petrographic constitute of final slag for the dephosphorization converter by adding the LWS and the HS slags is dicalcium silicate , RO phase and glass phase.There are a little calcium ferrite phase in the LWS slag , which is helpful to dephosphorization.So there are better dephosphorization effects for the LWS and HS slags.
基金financially supported by the National Science and Technology Support Program (2008BAB32087)
文摘The pre-reduced Bayan Obo ferroniobium(FeNb)ore concentrate block was taken as raw materials for studying the physical properties of niobium-enriched slag and changes in niobium recovery rate.In addition,the dephosphorization rate of the slag under different melting-separation conditions was investigated using the melting-separation test.The research results demonstrate that(i)the niobium recovery rate and dephosphorization rate of the slag decrease with the increase in melting-separation temperature;(ii)the niobium recovery rate of the slag initially increases and then decreases with increase in basicity and time;and(iii)the dephosphorization rate of the slag increases with the increase in basicity and time.When the test was performed under the conditions of basicity of 0.6-0.7,time of 7-10min,and temperature of 1400-1450°C,the niobium recovery rate and dephosphorization rate are over 96%and 95%,respectively.By scanning electron microscopy,it is observed that niobium mainly exists in the form of calcium and titanium silicate within the slag phase,with uneven distribution.