Preparing titanium dioxide from titania-rich slag (TiO2 73wt%) by molten NaOH method has been developed. The effects of temperature and reaction time on the titanium conversion were investigated. The results showed ...Preparing titanium dioxide from titania-rich slag (TiO2 73wt%) by molten NaOH method has been developed. The effects of temperature and reaction time on the titanium conversion were investigated. The results showed that temperature had significant influence on the titanium conversion as well as the structure of the product. About 92% of titanium in the titania-rich slag could be converted after reacting with NaOH at 500℃ for 1 h. Metatitanic acid was formed through the steps of washing treatment, acid dissolution, and hydrolysis. Well-dispersed spherical titanium dioxide particles with an average size of 0.1-0.4μm can be obtained by calcination of metatitanic acid. In addition, the content of titanium dioxide in the product is up to 98.6wt%, which can be used as pigments after further treatment of coating and crushing.展开更多
This study describes the characteristics of mineral wool and its applications,and also introduces the traditional process of mineral wool made from molten blast furnace (BF) slag. Compared with high energy consumpti...This study describes the characteristics of mineral wool and its applications,and also introduces the traditional process of mineral wool made from molten blast furnace (BF) slag. Compared with high energy consumption of the traditional process,the production of mineral wool by using molten BF slag will be able to take full advantage of the sensible heat of molten slag, and also reduce production costs. However, there are also further issues to resolve such as how to obtain the required amount of molten BF slag and how to make it homogeneous. Based on the physical and chemical properties of the molten BF slag,the investigation into the relationship between temperature and viscosity under different acidity coefficients of the slag and silicon mixture was conducted. Combined with the crystallization and phase diagram of slag wool, its heat resistance, water resistance, durability and corrosion resistance were analyzed. Finally, trends of the technology development are proposed.展开更多
The oxygen-ion conductor, the reducing agent, and the molten oxide slag containing electroactive matter were used as constituent of a galvanic cell. Metal was directly electroreduced from molten slag using a short-cir...The oxygen-ion conductor, the reducing agent, and the molten oxide slag containing electroactive matter were used as constituent of a galvanic cell. Metal was directly electroreduced from molten slag using a short-circuit galvanic cell. The following galvanic cell was assembled in the present experiment: graphite rod, [-O]Fe-C saturated |ZrO2 (MgO) | Cu(1) + (FeO)(slag) , and molybdenum wire. The FeO electroreduction reaction was studied through measuring short circuit current by controlling factors such as temperature, the FeO content in molten slags, and the external circuit resistance. An overall kinetics model was developed to describe the process of FeO electroreductiono It was found that the modeled curves were in good agreement with the experimental values. The new oxide reduction method in the metallurgy with controlled oxygen flow was proposed and the metallurgical theory with controlled oxygen flow was developed.展开更多
Tailings from the vanadium extraction process are discarded each year as waste,which contain approximately 30 wt%of Fe.In our previous work,we extracted Fe and Mn from vanadium slag,and Fe and Mn existed in the form o...Tailings from the vanadium extraction process are discarded each year as waste,which contain approximately 30 wt%of Fe.In our previous work,we extracted Fe and Mn from vanadium slag,and Fe and Mn existed in the form of FeCl_(2) and MnCl_(2) after chlorination by NH_(4) Cl to achieve effective and green usage of waste containing Fe and Mn.In this work,square wave voltammetry(SWV)and cyclic voltammetry(CV)were applied to investigate the electrochemical behaviors of Fe^(2+)and Mn^(2+)in Na Cl-KCl melt at 800℃.The reduction processes of Fe^(2+)and Mn^(2+)were found to involve one step.The diffusion coefficients of FeCl_(2) and Mn Cl_(2) in molten salt of eutectic mixtures Na Cl-KCl molten salt were measured.The electrodeposition of Fe and Mn were performed using two electrodes at a constant cell voltage.The Mn/Fe mass ratio of the electrodeposited product in Na Cl-KCl-2.13 wt%FeCl_(2)-1.07 wt%Mn Cl_(2) was 0.0625 at 2.3 V.After the electrolysis of NaCl-KCl-2.13 wt%Fe Cl_(2)-1.07 wt%MnCl_(2) melted at 2.3 V,the electrolysis was again started under 3.0 V and the Mn/Fe mass ratio of the electrodeposited product was 36.4.This process provides a novel method to effectively separate Fe and Mn from simulated chlorinated vanadium slag.展开更多
The oxygen-ion-permeable membrane galvanic short-circuit method has been developed, in which pure metal was directly extracted from the molten oxide slag, and no external voltage is applied. The galvanic cell employed...The oxygen-ion-permeable membrane galvanic short-circuit method has been developed, in which pure metal was directly extracted from the molten oxide slag, and no external voltage is applied. The galvanic cell employed in the experiment was as follows: graphite rod|[O]Fe+C saturation|ZrO2(MgO)|(FeO)(slag)|Fe rod. The reduction current in the galvanic cell consisted of an external short-circuit current and an interior short-circuit current in the oxygen-ion-permeable membrane. The real-time variation of external circuit reduction ratio of the molten slag could be obtained from the curve of the external circuit current to the time.展开更多
A novel thermodynamic model-the molecular interaction volume model (MIVM) which can be reduced to the Flory-Huggins equation of polymer solution was employed for the prediction of component activities in the ternary...A novel thermodynamic model-the molecular interaction volume model (MIVM) which can be reduced to the Flory-Huggins equation of polymer solution was employed for the prediction of component activities in the ternary molten aluminosilicate slag CaO-Al2O3-SiO2 at different temperatures. The results show that the predicted values of activity of CaO, Al2O3 and SiO2 are in reasonably agreement with experimental data in some ranges of their concentrations which are about x1 〈0.25 for CaO, x2=0.05-0.55 for Al2O3 and x3=0.03-0.85 for SiO2. This further shows that MIVM requires only two binary parameters for each sub-binary system to predict activities of all components in a multicomponent solution and is the superior alternative in a molten slag.展开更多
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
The oxygen-ion-permeable membrane galvanic short-circuit method has been developed, in which pure metal was directly extracted from the molten oxide slag, and no external voltage is applied. The galvanic cell employed...The oxygen-ion-permeable membrane galvanic short-circuit method has been developed, in which pure metal was directly extracted from the molten oxide slag, and no external voltage is applied. The galvanic cell employed in the experiment was as follows: graphite rod|[O][ZrO(MgO)|(FeO))|Fe rod. The reduction current in the galvanic cell consisted of an external short-circuit current and an interior short-circuit current in the oxygen-ion-permeable membrane. The real-time variation of external circuit reduction ratio of the molten slag could be obtained from the curve of the external circuit current to the time.展开更多
Experimental studies on the rheological properties of a Ca O–Si O2–Al2O3–Mg O–Ti O2–(Ti C) blast furnace(BF) slag system were conducted using a high-temperature rheometer to reveal the non-Newtonian behavior of h...Experimental studies on the rheological properties of a Ca O–Si O2–Al2O3–Mg O–Ti O2–(Ti C) blast furnace(BF) slag system were conducted using a high-temperature rheometer to reveal the non-Newtonian behavior of heterogeneous titanium-bearing molten slag. By measuring the relationships among the viscosity, the shear stress and the shear rate of molten slags with different Ti C contents at different temperatures, the rheological constitutive equations were established along with the rheological parameters; in addition, the non-Newtonian fluid types of the molten slags were determined. The results indicated that, with increasing Ti C content, the viscosity of the molten slag tended to increase. If the Ti C content was less than 2wt%, the molten slag exhibited the Newtonian fluid behavior when the temperature was higher than the critical viscosity temperature of the molten slag. In contrast, the molten slag exhibited the non-Newtonian pseudoplastic fluid characteristic and the shear thinning behavior when the temperature was less than the critical viscosity temperature. However, if the Ti C content exceeded 4wt%, the molten slag produced the yield stress and exhibited the Bingham and plastic pseudoplastic fluid behaviors when the temperature was higher and lower than the critical viscosity temperature, respectively. When the Ti C content increased further, the yield stress of the molten slag increased and the shear thinning phenomenon became more obvious.展开更多
The activity of VO in molten ternary CaO-SiO_2-VO Slag has been determined by chemical equilibrium method, using tin as the solvent metal. The relation between the activity and the content of VO, as well as the effect...The activity of VO in molten ternary CaO-SiO_2-VO Slag has been determined by chemical equilibrium method, using tin as the solvent metal. The relation between the activity and the content of VO, as well as the effect of slag basicity on activity of VO. are discussed.展开更多
An approach was made to correlate the proposed model of ion-cluster structure and structural parameter of TiO_2-bearing pentan system of molten slag with properties.Re- sults showed that an increase of ions with 4-coo...An approach was made to correlate the proposed model of ion-cluster structure and structural parameter of TiO_2-bearing pentan system of molten slag with properties.Re- sults showed that an increase of ions with 4-coordination number in molten slag makes the increase of bulk viscosity and the decrease of density,while ions with 6-coordination number are the contrary.The structural parameter proposed is so fairly interrelated to the properties of slag,that it may be available for the prediction about properties.In comparison with ions of 4-coordination number.Ti is more effective than Al and Si.展开更多
Activity of TiO_2 in the molten blast furnace slag containing TiO_2 has been examined at 1500℃ by means of “molten slag-Sn” chemical equilibrium method,using metallic Sn as flux and graphite as deoxidizer,together ...Activity of TiO_2 in the molten blast furnace slag containing TiO_2 has been examined at 1500℃ by means of “molten slag-Sn” chemical equilibrium method,using metallic Sn as flux and graphite as deoxidizer,together with phase diagram caIculation.In the pentary slag system CaO-MgO-SiO_2-TiO_2-Al_2O_3,a_(TiO_2)=0.01—0.05 or 0.02—0.10 with pure liquid or solid TiO_2 as standard state,respectively.The activity and activity coefficient of TiO_2 in relation to concentration of TiO_2 have been discussed.展开更多
The vacuum treatment for simultaneous desulphurization and dephosphorization of hot metal and molten steel with pre melted CaO based slag was carried out. For pre treatment of hot metal, both desulphurization and d...The vacuum treatment for simultaneous desulphurization and dephosphorization of hot metal and molten steel with pre melted CaO based slag was carried out. For pre treatment of hot metal, both desulphurization and dephosphorization are improved with the increase of CaO in slag, but deteriorated with the increase of CaF 2 in slag. The average desulphurization and dephosphorization rate is 68 83 % and 78 46 %, respectively. For molten steel, the substitution of BaO for CaO in slag has minor effect on simultaneous desulphurization and dephosphorization. The desulphurization and dephosphorization rate is higher than 90 % and 50 % respectively with the lowest final sulfur and phosphorus mass percent being 0 001 2 % and 0 010 %, respectively. The overall effect of simultaneous desulphurization and dephosphorization of molten steel is better than that of hot metal.展开更多
The rate of reducing Fet O in CaO-SiO2-Al2O3-Fet O slags with carbon saturated in molten iron has been determined in a graphite crucible in the temperature range of 1673-1773K. The effects of temperature, slag basicit...The rate of reducing Fet O in CaO-SiO2-Al2O3-Fet O slags with carbon saturated in molten iron has been determined in a graphite crucible in the temperature range of 1673-1773K. The effects of temperature, slag basicity and FetO content on the reduction rate have also been discussed. Test results show that the reduction rate increases with increasing temperature or FEtO concentration in slags, and the reduction rate has a parabolic relation with the simple basicity or optical basicity of slag, the maximum reduction rate being observed at around CaO/SiO2=1.5 of molten slags. The reduction reaction order is 1. 73 or 1.80, and the reduction activation energy is 299.9 or 295.9 kJ/mol in regard to Fet O weight content or Fet O activity calculated by using regular solution model, respectively. The reduction rate of CaO-SiO2-Al2 O3-Fet O slags with carbon saturated in molten iron is in the range of 0.32-3.48 mol-O/cm2·s.展开更多
基金financially supported by the National Key Technologies R & D Program of China (No.2006BAC02A05)the National Basic Research Program of China (No. 2007CB613501)+1 种基金the Knowledge Innovation Program of the Chinese Academy of Sciences (No.KGCX2-YW-214)the Special Funds of "Mountain Tai Scholar" Construction Project
文摘Preparing titanium dioxide from titania-rich slag (TiO2 73wt%) by molten NaOH method has been developed. The effects of temperature and reaction time on the titanium conversion were investigated. The results showed that temperature had significant influence on the titanium conversion as well as the structure of the product. About 92% of titanium in the titania-rich slag could be converted after reacting with NaOH at 500℃ for 1 h. Metatitanic acid was formed through the steps of washing treatment, acid dissolution, and hydrolysis. Well-dispersed spherical titanium dioxide particles with an average size of 0.1-0.4μm can be obtained by calcination of metatitanic acid. In addition, the content of titanium dioxide in the product is up to 98.6wt%, which can be used as pigments after further treatment of coating and crushing.
文摘This study describes the characteristics of mineral wool and its applications,and also introduces the traditional process of mineral wool made from molten blast furnace (BF) slag. Compared with high energy consumption of the traditional process,the production of mineral wool by using molten BF slag will be able to take full advantage of the sensible heat of molten slag, and also reduce production costs. However, there are also further issues to resolve such as how to obtain the required amount of molten BF slag and how to make it homogeneous. Based on the physical and chemical properties of the molten BF slag,the investigation into the relationship between temperature and viscosity under different acidity coefficients of the slag and silicon mixture was conducted. Combined with the crystallization and phase diagram of slag wool, its heat resistance, water resistance, durability and corrosion resistance were analyzed. Finally, trends of the technology development are proposed.
基金Item Sponsored by National Natural Science Foundation of China (50274008 ,50574011) Provincial Natural Science Foundationof Hubei Province of China (2005ABA019)
文摘The oxygen-ion conductor, the reducing agent, and the molten oxide slag containing electroactive matter were used as constituent of a galvanic cell. Metal was directly electroreduced from molten slag using a short-circuit galvanic cell. The following galvanic cell was assembled in the present experiment: graphite rod, [-O]Fe-C saturated |ZrO2 (MgO) | Cu(1) + (FeO)(slag) , and molybdenum wire. The FeO electroreduction reaction was studied through measuring short circuit current by controlling factors such as temperature, the FeO content in molten slags, and the external circuit resistance. An overall kinetics model was developed to describe the process of FeO electroreductiono It was found that the modeled curves were in good agreement with the experimental values. The new oxide reduction method in the metallurgy with controlled oxygen flow was proposed and the metallurgical theory with controlled oxygen flow was developed.
基金the National Natural Science Foundation of China(Nos.51904286,51922003,51774027 and 51734002)the China Postdoctoral Science Foundation(No.2019M650848)。
文摘Tailings from the vanadium extraction process are discarded each year as waste,which contain approximately 30 wt%of Fe.In our previous work,we extracted Fe and Mn from vanadium slag,and Fe and Mn existed in the form of FeCl_(2) and MnCl_(2) after chlorination by NH_(4) Cl to achieve effective and green usage of waste containing Fe and Mn.In this work,square wave voltammetry(SWV)and cyclic voltammetry(CV)were applied to investigate the electrochemical behaviors of Fe^(2+)and Mn^(2+)in Na Cl-KCl melt at 800℃.The reduction processes of Fe^(2+)and Mn^(2+)were found to involve one step.The diffusion coefficients of FeCl_(2) and Mn Cl_(2) in molten salt of eutectic mixtures Na Cl-KCl molten salt were measured.The electrodeposition of Fe and Mn were performed using two electrodes at a constant cell voltage.The Mn/Fe mass ratio of the electrodeposited product in Na Cl-KCl-2.13 wt%FeCl_(2)-1.07 wt%Mn Cl_(2) was 0.0625 at 2.3 V.After the electrolysis of NaCl-KCl-2.13 wt%Fe Cl_(2)-1.07 wt%MnCl_(2) melted at 2.3 V,the electrolysis was again started under 3.0 V and the Mn/Fe mass ratio of the electrodeposited product was 36.4.This process provides a novel method to effectively separate Fe and Mn from simulated chlorinated vanadium slag.
基金This work was financially supported by the National Natural Science Foundation of China (No.59934090) and the National Key Basic Research and Development Program of China (No.G1998061506)
文摘The oxygen-ion-permeable membrane galvanic short-circuit method has been developed, in which pure metal was directly extracted from the molten oxide slag, and no external voltage is applied. The galvanic cell employed in the experiment was as follows: graphite rod|[O]Fe+C saturation|ZrO2(MgO)|(FeO)(slag)|Fe rod. The reduction current in the galvanic cell consisted of an external short-circuit current and an interior short-circuit current in the oxygen-ion-permeable membrane. The real-time variation of external circuit reduction ratio of the molten slag could be obtained from the curve of the external circuit current to the time.
基金the National Natural Science Foundation of China under grant No.50764006the Applied Fundamental Research Foundation of Yunnan Province under Grant No.2006E0021M are gratefully acknowledged.
文摘A novel thermodynamic model-the molecular interaction volume model (MIVM) which can be reduced to the Flory-Huggins equation of polymer solution was employed for the prediction of component activities in the ternary molten aluminosilicate slag CaO-Al2O3-SiO2 at different temperatures. The results show that the predicted values of activity of CaO, Al2O3 and SiO2 are in reasonably agreement with experimental data in some ranges of their concentrations which are about x1 〈0.25 for CaO, x2=0.05-0.55 for Al2O3 and x3=0.03-0.85 for SiO2. This further shows that MIVM requires only two binary parameters for each sub-binary system to predict activities of all components in a multicomponent solution and is the superior alternative in a molten slag.
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%.
文摘The oxygen-ion-permeable membrane galvanic short-circuit method has been developed, in which pure metal was directly extracted from the molten oxide slag, and no external voltage is applied. The galvanic cell employed in the experiment was as follows: graphite rod|[O][ZrO(MgO)|(FeO))|Fe rod. The reduction current in the galvanic cell consisted of an external short-circuit current and an interior short-circuit current in the oxygen-ion-permeable membrane. The real-time variation of external circuit reduction ratio of the molten slag could be obtained from the curve of the external circuit current to the time.
基金financially supported by the National Science Foundation of China (Nos. 51090383 and 51174051)
文摘Experimental studies on the rheological properties of a Ca O–Si O2–Al2O3–Mg O–Ti O2–(Ti C) blast furnace(BF) slag system were conducted using a high-temperature rheometer to reveal the non-Newtonian behavior of heterogeneous titanium-bearing molten slag. By measuring the relationships among the viscosity, the shear stress and the shear rate of molten slags with different Ti C contents at different temperatures, the rheological constitutive equations were established along with the rheological parameters; in addition, the non-Newtonian fluid types of the molten slags were determined. The results indicated that, with increasing Ti C content, the viscosity of the molten slag tended to increase. If the Ti C content was less than 2wt%, the molten slag exhibited the Newtonian fluid behavior when the temperature was higher than the critical viscosity temperature of the molten slag. In contrast, the molten slag exhibited the non-Newtonian pseudoplastic fluid characteristic and the shear thinning behavior when the temperature was less than the critical viscosity temperature. However, if the Ti C content exceeded 4wt%, the molten slag produced the yield stress and exhibited the Bingham and plastic pseudoplastic fluid behaviors when the temperature was higher and lower than the critical viscosity temperature, respectively. When the Ti C content increased further, the yield stress of the molten slag increased and the shear thinning phenomenon became more obvious.
文摘The activity of VO in molten ternary CaO-SiO_2-VO Slag has been determined by chemical equilibrium method, using tin as the solvent metal. The relation between the activity and the content of VO, as well as the effect of slag basicity on activity of VO. are discussed.
文摘An approach was made to correlate the proposed model of ion-cluster structure and structural parameter of TiO_2-bearing pentan system of molten slag with properties.Re- sults showed that an increase of ions with 4-coordination number in molten slag makes the increase of bulk viscosity and the decrease of density,while ions with 6-coordination number are the contrary.The structural parameter proposed is so fairly interrelated to the properties of slag,that it may be available for the prediction about properties.In comparison with ions of 4-coordination number.Ti is more effective than Al and Si.
文摘Activity of TiO_2 in the molten blast furnace slag containing TiO_2 has been examined at 1500℃ by means of “molten slag-Sn” chemical equilibrium method,using metallic Sn as flux and graphite as deoxidizer,together with phase diagram caIculation.In the pentary slag system CaO-MgO-SiO_2-TiO_2-Al_2O_3,a_(TiO_2)=0.01—0.05 or 0.02—0.10 with pure liquid or solid TiO_2 as standard state,respectively.The activity and activity coefficient of TiO_2 in relation to concentration of TiO_2 have been discussed.
文摘The vacuum treatment for simultaneous desulphurization and dephosphorization of hot metal and molten steel with pre melted CaO based slag was carried out. For pre treatment of hot metal, both desulphurization and dephosphorization are improved with the increase of CaO in slag, but deteriorated with the increase of CaF 2 in slag. The average desulphurization and dephosphorization rate is 68 83 % and 78 46 %, respectively. For molten steel, the substitution of BaO for CaO in slag has minor effect on simultaneous desulphurization and dephosphorization. The desulphurization and dephosphorization rate is higher than 90 % and 50 % respectively with the lowest final sulfur and phosphorus mass percent being 0 001 2 % and 0 010 %, respectively. The overall effect of simultaneous desulphurization and dephosphorization of molten steel is better than that of hot metal.
文摘The rate of reducing Fet O in CaO-SiO2-Al2O3-Fet O slags with carbon saturated in molten iron has been determined in a graphite crucible in the temperature range of 1673-1773K. The effects of temperature, slag basicity and FetO content on the reduction rate have also been discussed. Test results show that the reduction rate increases with increasing temperature or FEtO concentration in slags, and the reduction rate has a parabolic relation with the simple basicity or optical basicity of slag, the maximum reduction rate being observed at around CaO/SiO2=1.5 of molten slags. The reduction reaction order is 1. 73 or 1.80, and the reduction activation energy is 299.9 or 295.9 kJ/mol in regard to Fet O weight content or Fet O activity calculated by using regular solution model, respectively. The reduction rate of CaO-SiO2-Al2 O3-Fet O slags with carbon saturated in molten iron is in the range of 0.32-3.48 mol-O/cm2·s.