The purpose of this work is to find a new way for utilizing the rich sodium sulfate resource to produce soda ash. A novel process is proposed which uses aqueous dichromate solution as working medium through decomposit...The purpose of this work is to find a new way for utilizing the rich sodium sulfate resource to produce soda ash. A novel process is proposed which uses aqueous dichromate solution as working medium through decomposition of calcium carbonate in aqueous sodium dichromate, complex decomposition of aqueous sodium sulfate and calcium chromate, regeneration of sodium dichromate and production of sodium bicarbonate from carbonation of aqueous sodium chromate solution, processing and utilization of byproduct calcium sulfate, and production of sodium carbonate from sodium bicarbonate. The process has the features of less corrosion and pollution and low energy consumption.展开更多
Alkaline metals and hydrogen titanates are of great interest for possible applications. The qualities of soda ash and Rosetta ilmenite ore concentrate pellets were investigated. The kinetic formation of sodium titanat...Alkaline metals and hydrogen titanates are of great interest for possible applications. The qualities of soda ash and Rosetta ilmenite ore concentrate pellets were investigated. The kinetic formation of sodium titanate via roasting of soda ash and ilmenite pellets and powder was studied in the temperature range of 800。C to 900。C.展开更多
During continuous casting,properties of mold flux and mineralogical structures of flux film play important roles in controlling steel quality.The effect of soda ash on the physical properties and crystallization chara...During continuous casting,properties of mold flux and mineralogical structures of flux film play important roles in controlling steel quality.The effect of soda ash on the physical properties and crystallization characteristics of mold flux was investigated using process mineralogy,including polarizing microscopy,X-ray diffraction,and electron microprobe,etc.Mold flux was mainly prepared using cement clinker and industrial mineral materials under laboratory conditions,and the mineralogical structures of the flux film were systematically identified and quantitatively analyzed.The results showed that,by increasing the soda ash content from 10mass% to 18mass%,the crystallization temperature,critical cooling rate and crystallization ratio of the flux film decreased,but the crystallization ratio still reached 75% after adding soda ash,and the mineral compositions and microstructures of the flux film changed slightly.When the soda ash content exceeded 14mass%,the critical cooling rate and the crystallization ratio decreased slightly,whereas the mineral content of the flux film changed evidently,with a large amount of cuspidine precipitation and a significant decrease in the wollastonite content until it reached zero,which resulted in deterioration of the lubrication of the flux film.展开更多
By desilication treatment,the Al2O3/SiO2 molar ratio of coal fly ash could be improved to the range of 1.63-2.0.The desilicated coal fly ash(DSCFA)was enriched in alumina extraction.A processing technology was develop...By desilication treatment,the Al2O3/SiO2 molar ratio of coal fly ash could be improved to the range of 1.63-2.0.The desilicated coal fly ash(DSCFA)was enriched in alumina extraction.A processing technology was developed for alumina extraction from the DSCFA with the lime sintering process.Ca/(SiO2+TiO2)molar ratio,and NaO/Al2O3 molar ratio,sintering time,and temperature were the most significant parameters impacting on the aluminum extraction efficiency.The optima aluminum extraction efficiency was obtained under conditions of Ca/(SiO2+TiO2)molar ratio of 2.0,NaO/Al2O3 molar ratio of 0.98,and sintering at 1 200 ℃for 60 min.Astandard industrial dissolution method was used under conditions of caustic ratio(αk=n(NaO)/n(Al2O3)of 2.0,Al2O3 concentration of 50 g/L,sodium hydroxide concentration(Nk)of 60.78 g/L,Na2CO3 concentration of 10 g/L,temperature of 85℃, and dissolution duration of 10 min.The final aluminum extraction efficiency was 90%.展开更多
This work is detailed towards ascertaining the thermodynamics and kinetics considerations for the production of caustic soda from brine and soda ash. The thermodynamics considers the Gibbs free energy;which is the min...This work is detailed towards ascertaining the thermodynamics and kinetics considerations for the production of caustic soda from brine and soda ash. The thermodynamics considers the Gibbs free energy;which is the minimum electrical work that must be supplied to an electric cell to drive the electrochemical reactions and its relationship with other thermodynamic parameters. The kinetics aspect of this research deduces the reaction rate equations and also predicts via feasible calculations the rate of the reaction, rate constant and order of the reaction. The examination of the thermodynamic analysis shows that the reaction is exothermic, positive value of entropy indicates that there is intrinsic energy which can be converted into work by a perfect electrolytic reaction process. The work determines the extent and the rate of the production process of caustic soda production and as such a pilot plant production of caustic soda from naturally occurring seawater via the diaphragm cell may be developed. The results obtained have shown that the cell potential using the Nerst equation for the production of optimum product caustic soda are: E = 0.5232 volt and the reaction is of second order. The rate of the reaction r=6.264×10−12 mol⋅cm−2⋅s−1 and the rate constant K2=9.2591×10−5cm⋅s−1.展开更多
基金Supported by the National Natural Science Foundation of China (No. 50234040) the High-Technology Research and Development Program of China (No. 2001AA6407010).
文摘The purpose of this work is to find a new way for utilizing the rich sodium sulfate resource to produce soda ash. A novel process is proposed which uses aqueous dichromate solution as working medium through decomposition of calcium carbonate in aqueous sodium dichromate, complex decomposition of aqueous sodium sulfate and calcium chromate, regeneration of sodium dichromate and production of sodium bicarbonate from carbonation of aqueous sodium chromate solution, processing and utilization of byproduct calcium sulfate, and production of sodium carbonate from sodium bicarbonate. The process has the features of less corrosion and pollution and low energy consumption.
文摘Alkaline metals and hydrogen titanates are of great interest for possible applications. The qualities of soda ash and Rosetta ilmenite ore concentrate pellets were investigated. The kinetic formation of sodium titanate via roasting of soda ash and ilmenite pellets and powder was studied in the temperature range of 800。C to 900。C.
基金Item Sponsored by National Natural Science Foundation of China(51174073)National Natural Science Foundation-National Iron and Steel Joint Research of China(U1360106)
文摘During continuous casting,properties of mold flux and mineralogical structures of flux film play important roles in controlling steel quality.The effect of soda ash on the physical properties and crystallization characteristics of mold flux was investigated using process mineralogy,including polarizing microscopy,X-ray diffraction,and electron microprobe,etc.Mold flux was mainly prepared using cement clinker and industrial mineral materials under laboratory conditions,and the mineralogical structures of the flux film were systematically identified and quantitatively analyzed.The results showed that,by increasing the soda ash content from 10mass% to 18mass%,the crystallization temperature,critical cooling rate and crystallization ratio of the flux film decreased,but the crystallization ratio still reached 75% after adding soda ash,and the mineral compositions and microstructures of the flux film changed slightly.When the soda ash content exceeded 14mass%,the critical cooling rate and the crystallization ratio decreased slightly,whereas the mineral content of the flux film changed evidently,with a large amount of cuspidine precipitation and a significant decrease in the wollastonite content until it reached zero,which resulted in deterioration of the lubrication of the flux film.
基金Project(YFZX(0804))supported by Science Foundation of the Pingshuo Coal Industry Company,China
文摘By desilication treatment,the Al2O3/SiO2 molar ratio of coal fly ash could be improved to the range of 1.63-2.0.The desilicated coal fly ash(DSCFA)was enriched in alumina extraction.A processing technology was developed for alumina extraction from the DSCFA with the lime sintering process.Ca/(SiO2+TiO2)molar ratio,and NaO/Al2O3 molar ratio,sintering time,and temperature were the most significant parameters impacting on the aluminum extraction efficiency.The optima aluminum extraction efficiency was obtained under conditions of Ca/(SiO2+TiO2)molar ratio of 2.0,NaO/Al2O3 molar ratio of 0.98,and sintering at 1 200 ℃for 60 min.Astandard industrial dissolution method was used under conditions of caustic ratio(αk=n(NaO)/n(Al2O3)of 2.0,Al2O3 concentration of 50 g/L,sodium hydroxide concentration(Nk)of 60.78 g/L,Na2CO3 concentration of 10 g/L,temperature of 85℃, and dissolution duration of 10 min.The final aluminum extraction efficiency was 90%.
文摘This work is detailed towards ascertaining the thermodynamics and kinetics considerations for the production of caustic soda from brine and soda ash. The thermodynamics considers the Gibbs free energy;which is the minimum electrical work that must be supplied to an electric cell to drive the electrochemical reactions and its relationship with other thermodynamic parameters. The kinetics aspect of this research deduces the reaction rate equations and also predicts via feasible calculations the rate of the reaction, rate constant and order of the reaction. The examination of the thermodynamic analysis shows that the reaction is exothermic, positive value of entropy indicates that there is intrinsic energy which can be converted into work by a perfect electrolytic reaction process. The work determines the extent and the rate of the production process of caustic soda production and as such a pilot plant production of caustic soda from naturally occurring seawater via the diaphragm cell may be developed. The results obtained have shown that the cell potential using the Nerst equation for the production of optimum product caustic soda are: E = 0.5232 volt and the reaction is of second order. The rate of the reaction r=6.264×10−12 mol⋅cm−2⋅s−1 and the rate constant K2=9.2591×10−5cm⋅s−1.
