富硅一水硬铝石型铝土矿与硫酸铵焙烧反应行为机理

一水硬铝石型铝土矿中铝硅的分离在氧化铝生产中具有重要意义.硫酸铵低温焙烧技术能有效提取矿物中的金属元素,本文以硫酸铵为提取剂,将一水硬铝石型铝土矿与硫酸铵共同焙烧提取铝.实验考察了焙烧过程中铝提取的主要影响因素:焙烧温度,硫酸铵用量,焙烧时间和矿物粒度.结果表明,在400°C下保温2 h、硫酸铵用量为理论值的2.5倍、...     

十二烷基三甲氧基硅烷对十二胺浮选铝硅矿物的影响

通过单矿物浮选实验、动电位测定及红外光谱分析,研究了十二胺(DDA)和十二烷基三甲氧基硅烷(WD-10)2种浮选药剂对一水硬铝石和高岭石的浮选行为和作用机理.结果表明:在酸性条件下,十二胺单独使用时,高岭石的回收率略高于一水硬铝石,两种矿物的可浮性差异不大,不能有效实现高岭石与一水硬铝石的浮选分离;十二烷基三甲氧基硅烷单独使用时对高岭石和一水硬铝石均无捕收作用;与单用十二胺相比,DDA+WD-10的组合捕收剂对硅酸盐矿物浮选能力强,选择性好.在pH=4～5.5的范围及最佳药剂配比条件下,高岭石回收率在75%以上,而一水硬铝石回收率只有20%左右,能有效实现铝硅矿物的反浮选分离.     

一水硬铝石焙烧矿增浓溶出及其机理

为了深入研究焙烧对一水硬铝石矿增浓溶出过程的影响及其活化焙烧强化溶出的机理,采用化学法提纯,从铝土矿中得到了高纯的一水硬铝石矿;经不同温度焙烧后进行增浓溶出,考察了焙烧温度对铝土矿增浓溶出效果的影响。研究结果表明：在一定温度范围内,焙烧矿的溶出性能优于未焙烧矿;当焙烧时间一定时,在525℃焙烧的一水硬铝石矿溶出性能明显改善,焙烧矿石中氧化铝可几乎全部溶出,通过X射线衍射对物相、晶体点阵常数的测定以及扫描电镜对焙烧提纯矿形貌的观察,认为强化溶出的主要机制为：一水硬铝石提纯矿在一定条件下焙烧后,由结晶完整的一水硬铝石正交晶型逐渐向结晶不完整的刚玉转变,且矿石表面出现大量的裂纹和孔洞,增加了矿石的比表面积,从而强化了其与碱液反应的能力,溶出性能得到明显改善。     

金龙铝土矿晶体化学和嵌布特征

采用XRD、原矿化学多项分析、镜下鉴定及扫描电镜等对广西金龙铝土矿的物质组成、化学成分、晶体化学和嵌布特征进行了系统研究.结果表明:矿石以一水硬铝石为主(36.5%),含三水铝石、黏土矿物、赤铁矿等;Al2O3平均品位约44%,铝硅比均值约3.57,属于低品位铝土矿石;一水硬铝石属斜方晶系双锥体类,在矿石中嵌布主要呈自形和半自形晶、豆状和鲕状、隐晶质和微晶集合体3种形式,与高岭石、叶腊石等嵌布伴生;高岭石属三斜晶系的层状结构硅酸盐矿物,多以隐晶质致密状或土状集合体形式嵌布;叶腊石属单斜晶系的二八面体结构含水铝硅酸盐矿物,以隐晶质细小鲕片状集合体形式嵌布,伴有赤铁矿、金红石等.     

六偏磷酸钠在铝土矿浮选中的作用

通过浮选试验、吸附量测试、动电位测试,研究了六偏磷酸钠对一水硬铝石和高岭石2种矿物浮选行为的影响以及其作用机理。结果表明：六偏磷酸钠对这2种矿物均有抑制作用,当捕收剂量增大时,被六偏磷酸钠抑制的一水硬铝石的可浮性逐渐变好,而高岭石则变化不大。其主要原因在于六偏磷酸钠与捕收剂油酸钠在这2种矿物表面存在竞争吸附,而油酸钠在一水硬铝石表面的吸附能力强于在高岭石表面的吸附,使得在一定捕收剂用量下,六偏磷酸钠抑制高岭石的上浮而不抑制一水硬铝石。这为2种矿物浮选分离提供了依据;此外,六偏磷酸钠对矿物表面的动电位影响较大,增大了矿物之间的静电排斥力,有利于矿泥的分散,增强了浮选分离的选择性。     

贵州清镇老黑山铝土矿床成矿物质来源及矿床成因

老黑山铝土矿赋存于下石炭统九架炉组黏土岩中,矿石自然类型有碎屑状、致密状、土状３种,主要矿物有一水硬铝石、高岭石、白云母等。铝土矿中的Ｂｅ含量为（０.１３～６.２３）×１０^－６,Ｔｈ／Ｕ值在１.４６～５.０７,Ｓｒ／Ｂａ的平均值为１.５。矿床地球化学研究结果表明,研究区铝土矿矿床的成矿母岩来源于下伏地层,是下伏的碳酸盐岩石经红土化作用及海侵、地表水径流作用搬运至低洼区域聚集沉积成岩,形成以富铝黏土矿物为主的初始富集层,以差异升降为主的构造运动导致初始富集层暴露地表或浅表,富铝的矿物（高岭石等）再经风化淋滤改造,进一步脱硅、富铝作用形成品位较高的铝土矿。矿床成因属古风化壳迁移—沉积—改造型铝土矿矿床,沉积环境为海相的潮坪－泻湖环境。     

N,N-二乙基-N-十六烷基胺的合成及其对铝硅矿物浮选性能的影响

以十六胺、甲酸和乙醛为原料,合成了阳离子捕收剂N,N-二乙基-N-十六烷基胺(DEN16),通过单矿物和人工混合矿浮选实验以及红外光谱和Zeta电位测试,考察了其对一水硬铝石、高岭石和伊利石的浮选行为以及矿物与药剂的作用机理.浮选结果表明:在pH=5～5.5,DEN16用量为2×10-4mol/L时,高岭石、伊利石的回收率均高于82%,而一水硬铝石仅为60%;人工混合矿浮选精矿的铝硅比均高于20,说明在pH8时,以DEN16为捕收剂可以实现铝硅酸盐与一水硬铝石的分离.红外光谱和Zeta电位研究结果表明,DEN16与3种矿物的作用皆为静电吸附,且与高岭石和伊利石的作用强于一水硬铝石.     

中低品位铝土矿浮选柱短流程分选研究

我国铝土矿绝大多数为中低铝硅比的一水硬铝石型,矿物嵌布粒度细,分选困难.在分析铝土矿矿石性质的基础上,利用旋流-静态微泡浮选柱对中低品位铝土矿进行分选,考察了捕收剂用量、循环压力、处理量等因素对浮选效果的影响.研究结果表明:铝土矿易泥化,微细粒级含量高,其有效分选是关键;随着捕收剂用量、循环泵压力、处理量的增大,氧化铝回收率增加、精矿铝硅比下降;当捕收剂用量1000g/t,循环泵压力0.17MPa,处理量4.0t/(m2.h)时,精矿铝硅比8.02～8.13,氧化铝回收率88.77%～90.01%.采用"一粗一精"两段浮选柱分选可以完成浮选机"一粗两精两扫"五段分选作业,分选流程短,工艺简洁.     

阴离子淀粉对一水硬铝石和伊利石浮选行为的影响

通过浮选实验、动电位和吸附量测定,考察了阴离子淀粉在一水硬铝石和伊利石浮选分离中的效果与作用机理.单矿物浮选实验表明,在阳离子捕收剂(DTAC)体系中,阴离子型淀粉(LSDZ)在pH=4～11的范围内抑制了一水硬铝石的浮选.当pH=6,c(DTAC):3×10-4 mol/L时,随着阴离子淀粉LSDZ用量的提高,一水硬铝石被抑制;当c(LSDZ)＜40 mg/L时,活化伊利石的浮选,继续提高淀粉用量,则伊利石被抑制.结果表明:阴离子淀粉是反浮选分离一水硬铝石和伊利石的有效调整剂,LSDZ通过氢键与静电力作用吸附在铝硅矿物表面,阳离子捕收剂使矿物表面ζ-电位正移,阴离子淀粉使矿物表面ζ-电位负移,且阴离子淀粉的加入能促进捕收荆DTAC在矿物表面的吸附.     

碳酸钠对细粒铝硅酸盐矿物分散行为的影响

碳酸钠（Na2CO3）是铝土矿浮选脱硅工艺中的高效分散剂，通过沉降试验系统地研究了pH值和Na2CO3用量对一水硬铝石、高岭石、伊利石和叶腊石分散行为的影响．试验结果表明，4种单矿物在pH〈4的酸性条件下形成显著聚团，在碱性条件下则呈分散状态．其中，伊利石和叶蜡石在pH〉6，高岭石和一水硬铝石在pH〉9时处于较好分散状态．动电位测定和DLVO理论计算结果表明，添加Na2CO3后，4种单矿物的表面ζ电位的负值均显著增大，导致矿物颗粒之间的静电排斥作用增大，从而增强了4种矿物颗粒间的分散性．     

Separation of aluminosilicates and diaspore from diasporic-bauxite by selective flocculation

The flocculation tests of four pure minerals (diaspore, kaolinite, illite, pyrophyllite) and bauxite ore were investigated by the sedimentation. The dispersion behavior of the four pure minerals shows a very good consistency with the variation of zeta potential. The concentrate with the mass ratio of Al2O3 to SiO2 (m(Al2O3)/m(SiO2)) 8.90 and the recovery of Al2O3 86.98% is obtained from bauxite ore (m(Al2O3)/m(SiO2)=5.68) in pH range of 9.5-10.0 by using sodium carbonate (5 kg/t) and sodium polyacrylate (7 g/t) as dispersant and flocculant respectively. Sodium carbonate acts as both pH modifier and favorable dispersant for aluminosilicates. The high performance of sodium polyacrylate on flocculation for diaspore is contributed to the carboxyl of sodium polyacrylate that interacts with active Al sites on diaspore by chemical absorption, and the hydrogen bond effects between hydroxyl group of macromolecule and surface Al--OH on diaspore to accelerate the sedimentation of diaspore.     

Interactions between bubble and particles of key minerals of diasporic bauxite through the extended DLVO theory

The flotation of diasporic bauxite is to separate diaspore (valuable mineral) from aluminosilicate minerals (gangue minerals, mainly including kaolinite, illite and pyrophyllite), and the microscopic interaction force between the two types of minerals and air bubbles determines the separation efficiency. In this paper, based on the extended Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, the van der Waals, electrostatic and hydrophobic interaction between particles of the four minerals mentioned above and air bubbles in collectorless solution were calculated first, and then diaspore and kaolinite were taken as examples to analyze the influence of various factors such as electrolyte concentration, mineral particle size, air bubble size, collector type (dodecylamine hydrochloride (DAH) and sodium oleate (NaOL)) and concentration, and pulp pH on the interactions between the particles of valuable mineral and gangue minerals and air bubbles. The results showed that the total extended DLVO interactions between the four minerals and air bubbles were repulsive in most cases in collectorless solution. The increase in electrolyte concentration reduced the interaction force or even changed the direction of the force under certain circumstances. The addition of DAH and NaOL can reduce the adhesion energy barrier of kaolinite-bubble and diaspore-bubble respectively. Each type of minerals exhibited a specific interface interaction response with air bubbles in each collector with different pH values. The research results have theoretical guiding significance for the optimization and directional control of diasporic bauxite flotation conditions.     

Flotation de-silicating from diasporic-bauxite with cetyl trimethylammonium bromide

1　INTRODUCTIONTheZetapotentialsofkaolinite ,illiteandchlo riteweremeasuredforthecoalflotation ,allthesethreeclaymineralswerenegativelychargedinthepHrangeof 2 .5 11.0 [1] .Theadsorptionofsodiumdode cylsulfateanddodecyltrimethylammoniumchlorideontokaolinitewasstudiedintheabsenceandpresenceofsodiumhexametaphosphate .Itwasfoundthatthepresenceofthelongchainphosphatedecreasedad sorptionoftheanionicsurfactantbutincreasedthead sorptionofthecationicsurfactant[2 ] .Acommercialmonoetheramineandac…     

云南省铝矿资源及其开发利用前景

云南的铝矿资源丰富,主要矿产分为沉积型铝土矿和霞石正长岩铝资源两大类.由于铝的用途越来越广,消量急剧上升,市场将长期呈现活跃,所以发展云南的铝矿业既有资源保证,又有市场前提,具有广阔的发展前景.     

Mineralogical and sink-float studies of Jajarm low-grade bauxite

Jajarm's bauxite deposits are mainly diasporic,and they have a low mass ratio of Al2O3/SiO2. It is necessary to increase the run-of-mine mass ratio before feeding the material to the Bayer process. Chemical analysis indicated that the low-grade bauxite sample from Jajarm contained 43.9wt% Al2O3 and 13.35wt% SiO2, resulting in a mass ratio of 3.29. According to mineralogical studies, the presence of aluminosilicate minerals such as kaolinite, illite, and quartz was the main reason for the decrease of the mas...     

Effect of quaternary ammonium salts on flotation behavior of aluminosilicate minerals

The electrokinetic properties and flotation of diaspore,kaolinite,pyrophyllite and illite with quaternary ammonium salts collectors were studied.The results of flotation tests show that the collecting ability of quaternary ammonium salts for the four minerals is in the order(from strong to weak)of octadecyl dimethyl benzyl ammonium chloride(ODBA),cetyl trimethyl ammonium bromide(CTAB),dodecyl trimethyl ammonium chloride(DTAC).Under the condition of alkalescence,it is possible to separate the diaspore from the silicate minerals such as kaolinite,illite and pyrophyllite using quaternary ammonium salts as collector.Isoelectric points(IEP)of diaspore,kaolinite,pyrophyllite and illite are pH=6.0,3.4,2.3 and 3.2,respectively.Quaternary ammonium salts can change ζ-potential of the aluminosilicate minerals obviously.The flotation mechanisms were explained by ζ-potential and Fourier transform infrared spectrum(FT-IR)measurements.The results demonstrate that only electrostatic interaction takes place between aluminosilicate     

A novel collector RL for flotation of bauxite

The flotation properties of single minerals such as diaspore, kaolinite and pyrophllite in bauxites were investigated using RL as collector. The effects of regulators and unavoidable ions on flotation were studied. Based on the results of single minerals flotation, the separation experiments of mixed minerals and bauxite ore were carried out. The results of closed circuit test on the ore show that, using RL as collector, Na2CO3 and (NaPO3)6 as modifiers, the grade of Al2O3 and SiO2 are respectively 70.74% and 6.37% in concentrate(Al/Si 11.11 ), and the recovery of Al2O3 can reach 90.52 %.     

Effect of hydroxamic acid polymers on reverse flotation of bauxite

The effect of hydroxamic acid starch (HAS) and hydroxamic acid polyacrylamide (HPAM) on the flotation of diaspore and kaolinite was investigated by flotation test. It is found that HAS depresses diaspore but activates kaolinite in acidic pulp,while HPAM activates both diaspore and kaolinite in the pH range of 2.0 - 10.5. The measurement of zeta potential shows that both HAS and HPAM can increase zeta potential of negatively charged diaspore, which indicates the existence of chemical bonding or hydrogen bonding between the reagents and diaspore.By covering the collector dodecyl amine(DDA) on diaspore surface, HAS increases the hydrophilicity of minerals and depresses the flotation of diaspore,however HPAM activates the flotation of diaspore by increasing the adsorption of DDA on diaspore surface.     

Synthesis of N, N-diethyl dodecyl amine and its flotation properties on bauxite

N, N-diethyl dodecyl amine（DEN12） was synthesized from dodecyl amine, formic acid and acetic aldehyde. The collecting property of DENI2 on diaspore, kaolinite and illite was investigated by flotation test and infrared spectrum. The results show that in the presence of 2.0× 10^-4 mol/L DEN12, the recoveries of kaolinite and illite are all higher than 78% and the recovery of diaspore is 50% in the pH range of 5.5-6.0. The mass ratio of A1203 to SiO2 in concentrate obtained from separation artificial mixture is higher than 10, suggesting that DEN12 can be used as a collector to separate the aluminosilicates from diaspore in bauxite ores at the pulp pH below 8. The measurements of the infrared spectrum approve that the action between aluminosilicates and tertiary amine collector is strong electrostatic adsorption and that of diaspore is weak electrostatic adsorption.