期刊文献+
共找到35篇文章
< 1 2 >
每页显示 20 50 100
Interaction of sulfur with iron compounds in sodium aluminate solutions 被引量:6
1
作者 李小斌 李重洋 +3 位作者 彭志宏 刘桂华 周秋生 齐天贵 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第2期608-614,共7页
Reaction behaviors of sulfur and iron compounds in sodium aluminate solutions were investigated. The results show that iron compounds can remarkably remove the S2 but cannot get rid of S2Oc2-, SO^2- and SO4^-2 in sodi... Reaction behaviors of sulfur and iron compounds in sodium aluminate solutions were investigated. The results show that iron compounds can remarkably remove the S2 but cannot get rid of S2Oc2-, SO^2- and SO4^-2 in sodium aluminate solutions. The removal efficiency of S^2- using ferrous compound and ferric compound can reach 86.10% and 92.70% respectively when the iron compounds were added with a molar ratio of 2:1 compared with the sulfur in liquors at 100℃. Moreover, several same compounds are formed in those two desulfurization processes with ferrous or ferric compounds, including erdite, hematite, amorphous ferrous sulfide, polymerized sulfur-iron compounds and ferric sulfate. The major difference between these two processes is that the erdite generated from ferrous compounds at the initial reaction stage will convert to a sodium-free product FeS2 at the subsequent stage. 展开更多
关键词 high-sulfur bauxite sodium aluminate iron compounds DESULFURIZATION MECHANISM
下载PDF
Adsorption of sodium polyacrylate at interface of dicalcium silicate-sodium aluminate solution 被引量:5
2
作者 于海燕 潘晓林 +3 位作者 丁婷婷 张武 刘涵 毕诗文 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第10期2323-2326,共4页
The adsorption isotherm of sodium polyacrylate on dicalcium silicate(2CaO-SiO2) in sodium aluminate solution at 80 ℃ was studied.The type of surface adsorption of sodium polyacrylate is saturated adsorption,and the... The adsorption isotherm of sodium polyacrylate on dicalcium silicate(2CaO-SiO2) in sodium aluminate solution at 80 ℃ was studied.The type of surface adsorption of sodium polyacrylate is saturated adsorption,and the adsorption behavior belongs to L-type,according with the monolayer adsorption model of Langmuir equation.The surface coverage of sodium polyacrylate is 1.06 mol/μm2.The relation curve between the surface pressure and the molecular area of adsorption film was obtained by Gibbs formula.The variation of interfacial energy caused by adsorption as well as the relationship between the relation curve and the type of adsorption was discussed. 展开更多
关键词 sodium aluminate solution sodium polyacrylate dicalcium silicate INTERFACE ADSORPTION
下载PDF
Removal of S^(2-) ion from sodium aluminate solutions with sodium ferrite 被引量:3
3
作者 李小斌 牛飞 +4 位作者 谭杰 刘桂华 齐天贵 彭志宏 周秋生 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第5期1419-1424,共6页
The synthesis of sodium ferrite and its desulfurization performance in S2 -bearing sodium aluminate solutions were investigated. The thermodynamic analysis shows that the lowest temperature is about 810 K for synthesi... The synthesis of sodium ferrite and its desulfurization performance in S2 -bearing sodium aluminate solutions were investigated. The thermodynamic analysis shows that the lowest temperature is about 810 K for synthesizing sodium ferrite by roasting the mixture of ferric oxide and sodium carbonate. The results indicate that the formation process of sodium ferrite can be completed at 1173 K for 60 min, meanwhile raising temperature and reducing NazCO3 particle size are beneficial to accelerating the formation of sodium ferrite. Sodium ferrite is an efficient desulfurizer to remove the S2- in aluminate solution, and the desulfurization rate can reach approximately 70% at 373 K for 60 min with the molar ratio of iron to sulfur of 1:1-1.5:1. Furthermore, the desulfurization is achieved by NaFeS2·2H2O precipitation through the reaction of Fe(OH)4 and S^2- in aluminate solution, and the desulfurization efficiency relies on the Fe(OH)4^- generated by dissolving sodium ferrite. 展开更多
关键词 sodium ferrite S^2- sodium aluminate solution DESULFURIZATION
下载PDF
Continuous changes in electrical conductivity of sodium aluminate solution in seeded precipitation 被引量:3
4
作者 刘桂华 李铮 +3 位作者 齐天贵 周秋生 彭志宏 李小斌 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第12期4160-4166,共7页
The mechanism of seeded precipitation of sodium aluminate solution was studied by measuring the seeded-precipitation rate and electrical conductivity online, as well as calculating the activity and fraction of ion pai... The mechanism of seeded precipitation of sodium aluminate solution was studied by measuring the seeded-precipitation rate and electrical conductivity online, as well as calculating the activity and fraction of ion pair. The results show that the electrical conductivity of sodium aluminate slurry linearly decreases with increasing aluminum hydroxide addition. Moreover, both the electrical conductivity of slurry and the difference in electrical conductivity between sodium aluminate solution and slurry remarkably decline in the first 60 min before gradually increasing in the preliminary 10 h and finally reaching almost the same level after 10 h. In low Na2 O concentration solution the activities of Na OH and Na Al(OH)4 in seeded precipitation are high, which can enlarge the difference in conductivity between slurry and solution. Additionally, more ion pairs exist in solution in preliminary seeded precipitation, and the adsorption of Na+Al(OH)4- on seed surface is likely to break the equilibrium of ion pair formation and to decrease the difference in conductivity in preliminary seeded precipitation. 展开更多
关键词 sodium aluminate solution seeded precipitation electrical conductivity activity coefficient ion pair
下载PDF
Pre-desilication and digestion of gibbsitic bauxite with lime in sodium aluminate liquor 被引量:13
5
作者 Xiao-lin Pan Hai-yan Yu +2 位作者 Kai-wei Dong Gan-feng Tu Shi-wen Bi 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2012年第11期973-977,共5页
The effect of lime on the pre-desilication and digestion of gibbsitic bauxite in synthetic sodium aluminate liquor at different tem- peratures was investigated. The bauxite is comprised of gibbsite, aluminogoethite, h... The effect of lime on the pre-desilication and digestion of gibbsitic bauxite in synthetic sodium aluminate liquor at different tem- peratures was investigated. The bauxite is comprised of gibbsite, aluminogoethite, hematite, kaolin, quartz, and minor boehmite. Lime in- creases the desilication efficiency of the bauxite during the pre-desilication process by promoting the conversion of sodalite and cancrinite to hydrogamet. Desilication reactions during the digestion process promoted by lime result in the loss of A1203 entering the red mud, but the amount of aluminogoethite-to-hematite conversion promoted by lime leads to the increase of aluminogoethific A1203 entering the digested liquor. The alumina digestion rate at 245~C is higher than that at 145 C due to the more pronounced conversion of aluminogoethite to hema- tite. The soda consumption during the digestion process decreases due to lime addition, especially at higher temperatures. 展开更多
关键词 bauxite ore treatment LIME sodium aluminate DESILICATION alumina Bayer process
下载PDF
INFLUENCE OF PREPARATIVE HISTORY ON STRUCTURE AND PROPERTIES OF SODIUM ALUMINATE SOLUTIONS 被引量:8
6
作者 Chen Nianyi Liu Miaoxiu +1 位作者 Yang Jinxiu Chi Likuan 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 1992年第2期28-31,共4页
It has been found that samples of sodium aluminate solutions with the same composition but different preparative history may have difTerent structure and physico-chemical properties.The structure of sodium-bearing alu... It has been found that samples of sodium aluminate solutions with the same composition but different preparative history may have difTerent structure and physico-chemical properties.The structure of sodium-bearing aluminate solutions change very slowly during the storage after preparation.Sodium aluminate solutions contain several ammunium-bearing anisons such as Al(OH)^(-)_(4),Al(OH)^(3-)_(6)and[(HO)_(3)Al-O-Al(OH)_(3)]^(2-),etc.These anions can convert to each other but the reactions are very slow owing to the formation or breakage of covalent Al-O bond.Hence the ratio between these anions approaches equilibrium very slowly after the preparation,and the structure or properties of these solution samples before equilibrium is reached depend on their preparative histosive. 展开更多
关键词 sodium aluminate solutions physico-chemical properties STRUCTURE preparative history
下载PDF
Mineral transition of desilication products precipitated in synthetic sodium aluminate solution under atmospheric pressure 被引量:7
7
作者 蒋涛 潘晓林 +2 位作者 吴艳 于海燕 涂赣峰 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第2期367-375,共9页
The liquor concentration, mineral proportion, crystal parameters and micro morphology of various desilication products(DSPs) precipitated in silica-supersaturated sodium aluminate solution at 95 ℃ under different r... The liquor concentration, mineral proportion, crystal parameters and micro morphology of various desilication products(DSPs) precipitated in silica-supersaturated sodium aluminate solution at 95 ℃ under different reaction conditions were systematically researched. The DSPs formed under atmospheric pressure comprise amorphous phase, zeolite A, zeolite and sodalite, and the DSPs concentration and crystallinity increase with the increase of initial silica concentration, initial molar ratio of caustic Na2O to Al2O3(αK) and desilication duration. Decreasing the initial silica concentration, initial αK and increasing the desilication duration can reduce the proportion of zeolite A. The zeolite and sodalite are the stable DSPs, while the precipitation of zeolite A occurs at a high silica-supersaturated state in sodium aluminate solution. The DSPs are precipitated in the form of agglomerates, but the morphologies of various DSPs are quite different. Both the molar ratios of Na2O to Al2O3 and SiO-2 to Al2O3 in DSPs increase with the increasing desilication duration, resulting in the increase of the cell volumes of various DSPs. The precipitation sequence of DSPs under atmospheric pressure is: amorphous phase→zeolite A→zeolite→sodalite. 展开更多
关键词 Bayer process DESILICATION sodium aluminate solution ZEOLITE SODALITE
下载PDF
Reaction kinetics and mechanism of calcium oxide in dilute sodium aluminate solution with oxalate based on lime causticization 被引量:7
8
作者 Bai-yong ZHANG Xiao-lin PAN +2 位作者 Jiang-zhou WANG Hai-yan YU Gan-feng TU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第6期1312-1322,共11页
The formation kinetics and mechanism of tricalcium aluminate hydrate and calcium oxalate in dilute sodium aluminate solution and sodium oxalate solution were studied respectively based on the lime causticization, and ... The formation kinetics and mechanism of tricalcium aluminate hydrate and calcium oxalate in dilute sodium aluminate solution and sodium oxalate solution were studied respectively based on the lime causticization, and the optimal conditions for removing the oxalate in dilute sodium aluminate solution as well as the mechanism were finally obtained.The formation processes of tricalcium aluminate hydrate and calcium oxalate are mainly controlled by the chemical reaction and the inner diffusion respectively,and the corresponding reaction rate equations as well as the apparent activation energy were calculated. The hydrocalumite with a spatially interleaved structure will form in dilute sodium aluminate solution with sodium oxalate, greatly removing the oxalate impurity by absorption. Calcium oxalate can be converted to tricalcium aluminate hydrate with the increasing reaction time. The oxalate causticization efficiency and the alumina loss rate can be over 90% and below 31% respectively when reacted at 50℃ with a stirring rate of 200 r/min. 展开更多
关键词 Bayer process lime causticization OXALATE KINETICS sodium aluminate solution
下载PDF
Influence of the Preparative History on Physico-chemical Properties of Sodium Aluminate Solutions 被引量:8
9
作者 陈念贻 柳妙修 杨金秀 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1992年第2期135-137,共3页
1.IntroductionSodium aluminate solutions are veryimportant intermediate products in alumin-ium metallurgy.The physico-chemicalproperties of sodium aluminate solutions areconcerned by metallurgists and engineersdealing... 1.IntroductionSodium aluminate solutions are veryimportant intermediate products in alumin-ium metallurgy.The physico-chemicalproperties of sodium aluminate solutions areconcerned by metallurgists and engineersdealing with alumina production[1].Thedata of viscosity,electroconductivity,UV 展开更多
关键词 sodium aluminate solution physicochemical properties preparative history
下载PDF
Periodical attenuation of Al(OH)_3 particles from seed precipitation in seeded sodium aluminate solution 被引量:5
10
作者 吴玉胜 张迪 +2 位作者 李明春 毕诗文 杨毅宏 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第3期528-532,共5页
Periodical attenuation of particles,which interferes seriously the normal alumina production,exists in Bayer process.In order to solve this problem,the rule of periodical attenuation of Al(OH) 3 particles was investig... Periodical attenuation of particles,which interferes seriously the normal alumina production,exists in Bayer process.In order to solve this problem,the rule of periodical attenuation of Al(OH) 3 particles was investigated by laboratory experiments under simulated industrial conditions.The results show that at higher temperature the variation period of particle size is shortened,while prolongs with more solid content.Particle size fluctuation amplitude reduces with the temperature rising but increases with the solid content increasing.Particle size distribution becomes more uniform by replenishing fine seeds,enabling the periodical fluctuation of Al(OH)3 particle size to be attenuated.Combining properly the additives with controlling the seed size is able to reduce the amplitude of periodical fluctuation and shorten the attenuation time.With unbalance of particle size distribution,the particles gradually become bigger,even inducing the decrease of the specific surface area of seeds,which is the major reason causing explosive attenuation of Al(OH)3 particles in seed precipitation process. 展开更多
关键词 Bayer process sodium aluminate solution periodical attenuation ADDITIVE seed precipitation
下载PDF
Low-temperature phase transitions of sodium aluminate solutions 被引量:5
11
作者 Wei LIU Zhou-lan YIN Zhi-ying DING 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第1期194-199,共6页
A series of low-temperature phase transitions of sodium aluminate solutions were studied by differential scanning calorimetry (DSC) and Raman spectroscopy. The results indicate that NaOH concentration is a primary imp... A series of low-temperature phase transitions of sodium aluminate solutions were studied by differential scanning calorimetry (DSC) and Raman spectroscopy. The results indicate that NaOH concentration is a primary impact factor for the binary eutectic point and ice melting temperature of sodium aluminate solutions with low NaOH concentration. In addition, the phase transition process of sodium aluminate solutions with low NaOH concentration from 123.15 to 283.15 K is divided into four steps: non-crystal to crystal, ternary eutectic reaction, binary eutectic reaction and ice melt. The projection phase diagram of NaOH-Al(OH)3-H2O system at low temperature was plotted, in which the ternary eutectic temperature for sodium aluminate solutions is 183.15 K. 展开更多
关键词 sodium aluminate solution low-temperature phase transition differential scanning calorimetry Raman spectroscopy eutectic reaction
下载PDF
Role of hydrazine and hydrogen peroxide in aluminium hydroxide precipitation from sodium aluminate solution 被引量:3
12
作者 N.K.SAHU C.K.SARANGI +4 位作者 B.DASH B.C.TRIPATHY B.K.SATPATHY D.MEYRICK I.N.BHATTACHARYA 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第2期615-621,共7页
Aluminium hydroxide precipitation from synthetic sodium aluminate solution was studied in the presence of hydrazine or hydrogen peroxide. The addition of low concentration of hydrazine is found to be effective, while ... Aluminium hydroxide precipitation from synthetic sodium aluminate solution was studied in the presence of hydrazine or hydrogen peroxide. The addition of low concentration of hydrazine is found to be effective, while higher amount of hydrogen peroxide is required to generate similar effect. XRD data confirm the product phase to be gibbsitic by nature. The scanning electron micrographs (SEM) show that agglomerated products form in the presence of hydrazine while fine discrete particles are produced with hydrogen peroxide. The probable mechanism of precipitation in the presence of hydrazine and hydrogen peroxide is also discussed. 展开更多
关键词 aluminium hydroxide HYDRAZINE hydrogen peroxide sodium aluminate PRECIPITATION
下载PDF
Behavior of calcium oxalate in sodium aluminate solutions 被引量:3
13
作者 Gui-hua LIU Wen-bo DONG +3 位作者 Tian-gui QI Qiu-sheng ZHOU Zhi-hong PENG Xiao-bin LI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第8期1879-1888,共10页
The stability of calcium oxalate is critical for the removal of sodium oxalate from sodium aluminate solutions.This studyinvestigated the behavior of calcium oxalate in sodium aluminate solution containing sodium carb... The stability of calcium oxalate is critical for the removal of sodium oxalate from sodium aluminate solutions.This studyinvestigated the behavior of calcium oxalate in sodium aluminate solution containing sodium carbonate.Results show that calciumoxalate can be converted to tricalcium aluminate hydrate(TCA)and calcium carbonate in sodium aluminate solution and sodiumcarbonate solution,respectively.Elevating temperature,extending residence time,or increasing caustic soda concentration enhancesthe conversion ratio of calcium oxalate in sodium aluminate solution;as a consequence,anti-causticisation occurs.Stability ofcalcium-containing compounds in sodium aluminate solution containing sodium carbonate differs from that in sodium aluminatesolution or sodium carbonate solution.Na2CO3in aluminate solution accelerates the transformation of calcium oxalate;thus,aluminais lost because of4CaO·Al2O3·CO2·11H2O and TCA formation.Calcium carbonate,4CaO·Al2O3·CO2·11H2O and calcium oxalatecan change into TCA in sodium aluminate solution at elevated temperature.Calcium oxalate remains relatively stable in dilutealuminate solution within a short residence time at low temperature.Thus,a novel process for removal of sodium oxalate by limecausticisation was presented and employed in an alumina refinery in China. 展开更多
关键词 calcium oxalate sodium aluminate solution sodium carbonate lime causticisation activity coefficient
下载PDF
Influence of silicate anions structure on desilication in silicate-bearing sodium aluminate solution 被引量:4
14
作者 刘桂华 张闻 +3 位作者 齐天贵 彭志宏 周秋生 李小斌 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第7期1569-1575,共7页
The structural changes of silicate anions in the desilication process with the addition of calcium hydrate alumino-carbonate were studied by measuring Raman spectra, infrared spectra and corresponding second derivativ... The structural changes of silicate anions in the desilication process with the addition of calcium hydrate alumino-carbonate were studied by measuring Raman spectra, infrared spectra and corresponding second derivative spectra. The results show that the desilication ratio in the solution prepared by the addition of sodium silicate(solution-SS) is much greater than that in the solution by the addition of green liquor(solution-GL), and low alumina concentration in the sodium aluminate solutions facilitates the desilication process. It is also shown that alumino-silicate anions in the solution-GL, and Q^3 polymeric silicate anions in solution-SS are predominant, respectively. In addition, increasing the concentration of silica favors respectively the formation of the alumino-silicate or the Q^3 silicate anions in the solution-GL or the solution-SS. Therefore, it can be inferred that the low desilication ratio in the silicate-bearing aluminate solution is mainly attributed to the existence of alumino-silicate anions. 展开更多
关键词 DESILICATION silicate anion STRUCTURE sodium aluminate solution second derivative spectrum oflR
下载PDF
Equilibrium concentration of lithium ion in sodium aluminate solution 被引量:4
15
作者 HUANG Wen-qiang LIU Gui-hua +4 位作者 LIU Peng QI Tian-gui LI Xiao-bin PENG Zhi-hong ZHOU Qiu-sheng 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第2期304-311,共8页
Excess lithium in alumina is significantly bad for aluminum reduction.In this study,the concentration variation of lithium ion in sodium aluminate solution with addition of synthetic lithium aluminate was investigated... Excess lithium in alumina is significantly bad for aluminum reduction.In this study,the concentration variation of lithium ion in sodium aluminate solution with addition of synthetic lithium aluminate was investigated.Elevating temperature,increasing caustic soda concentration,reducing alumina concentration or raising molar ratioαk improved equilibrium concentration of lithium ion in sodium aluminate solution.Agitation speed had a minimal effect on lithium ion concentration.Over 0.65 g/L lithium ion equilibrium concentration was observed in digestion process,whereas 35 mg/L lithium ion concentration remained in solution after precipitation time of 9 h.Moreover,equilibrium concentration decreased sharply from digestion of boehmite or diaspore to seed precipitation,about 95%lithium was precipitated into red mud(bauxite residue)and aluminum hydroxide.This study provides a valuable perspective in removal or extraction of lithium from sodium aluminate solution in alumina refineries. 展开更多
关键词 lithium ion equilibrium concentration sodium aluminate solution DIGESTION PRECIPITATION
下载PDF
Effect of oxalate on seed precipitation of gibbsite from sodium aluminate solution 被引量:4
16
作者 YU Hai-yan ZHANG Bai-yong +1 位作者 PAN Xiao-lin TU Gan-feng 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第3期772-779,共8页
The precipitation performance and kinetics of gibbsite from sodium aluminate solution with different sodium oxalate concentrations as well as the corresponding influence mechanism of oxalate during the seed precipitat... The precipitation performance and kinetics of gibbsite from sodium aluminate solution with different sodium oxalate concentrations as well as the corresponding influence mechanism of oxalate during the seed precipitation process were systematically investigated by physicochemical properties test,using SEM and Raman spectra.As the concentration of sodium oxalate increases,both the precipitation rate and particle size of gibbsite decrease.The presence of sodium oxalate not only increases the viscosity of sodium aluminate solution,but also promotes the transformation of Al(OH)4^? to Al2O(OH)6^2?.The overall reaction rate constant decreases and the apparent activation energy of gibbsite increases with the increasing sodium oxalate concentration,the rate controlling step of which is chemical reaction.The needle-like sodium oxalate precipitates on the gibbsite crystals and covers the active Al(OH)3 seed sites,which leads to the lower precipitation rate and the finer particle size of gibbsite during the seed precipitation process. 展开更多
关键词 sodium oxalate sodium aluminate solution gibbsite precipitation KINETICS Raman spectra
下载PDF
Effect of lithium ion on seed precipitation from sodium aluminate solution 被引量:3
17
作者 Wen-qiang HUANG Gui-hua LIU +4 位作者 Jin-bin JU Xiao-bin LI Qiu-sheng ZHOU Tian-gui QI Zhi-hong PENG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第6期1323-1331,共9页
Effect of lithium ion in sodium aluminate solution on precipitation rate,lithium content,morphology,and crystallization of alumina trihydrate(ATH) was investigated. Results showed that increasing lithium ion concentra... Effect of lithium ion in sodium aluminate solution on precipitation rate,lithium content,morphology,and crystallization of alumina trihydrate(ATH) was investigated. Results showed that increasing lithium ion concentration in solution improved the precipitation rate and lithium content in ATH,whereas reduced the mass fraction of lithium precipitation from solution. Lithium ion in solution generated the fine ATH, and thereafter significantly increased the total particle number due to the preferential nucleation.Elevating temperature or reducing lithium ion concentration decreased lithium content in ATH and reduced the fine particle amount.Moreover, lithium ion in the solution changed the morphology of ATH by improving the growth of the(110) and(200) planes of gibbsite.A large amount of fine bar-or flake-shaped ATH attached on the coarse particles also benefited the secondary nucleation and led to the poor strength of alumina.All results will further contribute to improving the quality of alumina. 展开更多
关键词 LITHIUM sodium aluminate solution seed precipitation alumina trihydrate
下载PDF
Effects of iron-containing phases on transformation of sulfur-bearing ions in sodium aluminate solution 被引量:3
18
作者 Xiao-bin LI Fei NIU +3 位作者 Gui-hua LIU Tian-gui QI Qiu-sheng ZHOU Zhi-hong PENG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第4期908-916,共9页
Sulfides in the high-sulfur bauxite lead to serious steel equipment corrosion and alumina product degradation via theBayer process,owing to the reactions of sulfur and iron-containing phases in the sodium aluminate so... Sulfides in the high-sulfur bauxite lead to serious steel equipment corrosion and alumina product degradation via theBayer process,owing to the reactions of sulfur and iron-containing phases in the sodium aluminate solution.The effects ofiron-containing phases on the transformation of sulfur-bearing ions(S2?,223S O?,23SO?and24SO?)in sodium aluminate solutionwere investigated.Fe,Fe2O3and Fe3O4barely react with23SO?and24SO?,but all of them,particularly Fe,can promote theconversion of223S O?to23SO?and S2?in sodium aluminate solution.Fe can convert to3Fe(OH)?in solution at elevatedtemperatures,and further react with S2?to form FeS2,but Fe2O3and Fe3O4have little influence on the reaction behavior of S2?insodium aluminate solution.Increasing temperature,duration,dosage of Fe,mole ratio of Na2Ok to Al2O3and caustic sodaconcentration are beneficial to the transformation of223S O?to23SO?and S2?.The results may contribute to the development oftechnologies for alleviating the equipment corrosion and reducing caustic consumption during the high-sulfur bauxite treatment bythe Bayer process. 展开更多
关键词 high-sulfur bauxite sodium aluminate solution sulfur-bearing ion iron-containing phase transformation
下载PDF
RAMAN SPECTRA OF SODIUM ALUMINATE SOLUTIONS WITH HIGH-CAUSTIC RATIO AND HIGH CONCENTRATION 被引量:2
19
作者 LIU Miaoxiu CAO Yilin CHEN Nianyi Shanghai Institute of Metallurgy,Academia Sinica,Shanghai,ChinaZHUANG Zhicheng Shanghai Jiaotong University,Shanghai,China Professor,Shanghai Institute of Metallurgy,Academia Sinica,Shanghai 200050,China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1992年第9期224-226,共3页
The constitution of high-caustic ratio and highly concentrated sodium aluminate solutions has been investigated by Raman spectra method.By comparison with the Raman spectra of crystalline solids of Ca_3[Al(OH)_6]_2 an... The constitution of high-caustic ratio and highly concentrated sodium aluminate solutions has been investigated by Raman spectra method.By comparison with the Raman spectra of crystalline solids of Ca_3[Al(OH)_6]_2 and Ba_2[Al_2(OH)_(10)],it can be concluded that AI(OH)_6^(3-)ion and perhaps its polymers may be formed in these solutions. 展开更多
关键词 high caustic ratio sodium aluminate solution Raman spectra
下载PDF
Model of apparent crystal growth rate and kinetics of seeded precipitation from sodium aluminate solution 被引量:3
20
作者 李小斌 刘志坚 +3 位作者 徐晓辉 周秋生 彭志宏 刘桂华 《Journal of Central South University of Technology》 EI 2005年第6期662-666,共5页
Based on the population balance equation in a batch crystallizer characteristic of seeded precipitation, a model to calculate the rate of apparent crystal growth of aluminum hydroxide from the size distribution was de... Based on the population balance equation in a batch crystallizer characteristic of seeded precipitation, a model to calculate the rate of apparent crystal growth of aluminum hydroxide from the size distribution was deve- loped. The simulation results indicate that the rate of apparent crystal growth during seeded precipitation exhibits a manifest dependence on the crystal size. In general, there is an obvious increase in the apparent crystal growth rate with the augment in crystal size. The apparent activation energy increases with the increase of characteristic crystal size, which indicates that the growth of small crystals is controlled by surface chemical reaction; it is gradually controlled by both the surface reaction and diffusion with the augment in crystal size. 展开更多
关键词 sodium aluminate solutions seeded precipitations aluminum hydroxides apparent crystal growth rates KINETICS
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部