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．     

Flotation of kaolinite and diaspore with hexadecyl dimethyl benzyl ammonium chloride

Tertiary amine was synthesized from fatty amine and formaldehyde. And then the synthesized tertiary amine was used to react with benzyl chloride to synthesize hexadecyl dimethyl benzyl ammonium chloride （1627） at ambient pressure. Using the synthesized 1627 as collector,the flotation properties of diaspore and kaolinite were investigated by single mineral and mixed mineral test. The flotation mechanism of diaspore,kaolinite and 1627 was discussed based on FTIR spectra. The results show that the mass ratio of aluminum to silicate achieves 15.02 and the recovery of alumina in concentrate is 43.07% using 1627 as a collector. The 1627 is found to be a more effective and a promising collector for reverse flotation to remove aluminum-silicate minerals from bauxite.     

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.     

Flotation behavior of four dodecyl tertiary amines as collectors of diaspore and kaolinite

The flotation of diaspore and kaolinite by one of a series of tertiary amines (DRN, DEN, DPN and DBN) was investigated. The tertiary amines show better floating recovery for kaolinite compared to diaspore. The maximum recovery D-value is 45% over a pH range from 3 to 8. FT-IR spectra confirm the presence of hydroxyl groups on the surface of kaolinite and diaspore. Zeta potential measurements show that the mineral surfaces are negatively charged over a wide pH range. Ionization of hydroxyl groups mainly accounts for the surface charging mechanism. The adsorption of tertiary amines onto the mineral surface is due mainly to electrostatic effects and the difference in electrostatic effect between a collector and the two minerals can explain the flotation separation. Inductive electronic and steric effects from the substituent groups result in different collecting powers for the four tertiary amines.     

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 %.     

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.     

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…     

A novel depressor useful for flotation separation of diaspore and kaolinite

The floatation of the minerals diaspore and kaolinite was investigated using dodecylamine as the collector.Separating diaspore and kaolinite in a neutral pH pulp is difficult since they then have similar floatability.A depressor consisting of an AlCl3/Na2SiO3 mixture is demonstrated to solve this problem.Diaspore sinking may be seen when the ratio of AlCl3 to Na2SiO3 is 3.1.We refer to this mixture as ATNO.The influence of Al/Si ratio in the feedstock and the grain size of fed minerals on separation was examined.An Al/Si ratio in the concentrate greater than 11 may be obtained when the Al/Si ratio of the feed is between 2.53 and 4.96.However,the grain size of the diaspore greatly influences the concentrate grade.Finer grain size of the diaspore (＜40 μm)in pulp makes the flotation separation less than ideal,no matter what the kaolinite grain size.     

Effects of sodium hexmetaphosphate on flotation separation of diaspore and kaolinite

1INTRODUCTION ThebauxiteinChinaismainlyofdiasporite type,withhighcontentofAl2O3butlowmassra tioofAl2O3toSiO2.Themainsiliceousminerals ofbauxitearekaolinite,illiteandpyrophyllite[1].Inordertoutilizethebauxiteeffectively,anewflotationdesilication Bayermethodwasdeveloped toproducealumina.Thepurposeofflotationdesil icationistoremovethesilicafromthebauxiteandtoincreasethemassratioofAl2O3toSiO2.Funda mentalresearchofreverseflotationdesilicationhas beenpaidmoreattentionduetoitsadvantageover…     

铝硅酸盐矿物新型浮选捕收剂的研究

考察了自行合成的新型阳离子表面活性剂QAS222对高岭石、叶蜡石和伊利石等铝硅酸盐矿物的浮选行为,试验研究结果表明：广泛矿浆pH范围内,新型阳离子表面活性剂QAS222对铝硅酸盐矿物既表现出较强的捕收力,又显示良好的选择性,是铝硅酸盐矿物的有效捕收剂,可应用于铝硅酸盐矿物的浮选富集,同样也可用于铝土矿、铁矿、萤石矿等选别过程的反浮选脱硅;在矿浆pH=11时,以QAS222为捕收剂,不添加其它任何抑制剂,成功地实现不同铝硅比的人工混合矿的反浮选脱硅,并获得较好的选别指标——当给矿A/S仅有2．7时,仍能获得精矿A／S为12．82,其中Al2O3品位77．79％、回收率69．91％的较好指标,且当给矿A／S不断增大时,精矿中的A/S,Al2O3的品位和回收率都有所提高．     

铝硅酸盐矿物浮选中捕收剂的设计合成及浮选机理的研究

铝土矿中脉石主要为高岭石、伊利石和叶蜡石等铝硅酸盐矿物,可以采用反浮选脱硅即通过选用合适的捕收剂将这些脉石矿物浮出.本文针对某铝土矿,结合Curis2软件中的高岭石晶体模型分析,从亲矿物基和非极性基两方面设计合成多胺类捕收剂DN12.通过浮选实验、浮选溶液化学计算、动电位测定和红外光谱测定研究该新型药剂对铝硅酸盐矿物的浮选作用及其机理.该捕收剂相对于常规捕收剂对铝硅酸盐矿物有更好的捕收效果,有效浮选pH区间为4~10.该捕收剂与铝硅酸盐矿物的作用以静电作用为主,同时也有氢键作用,从而增强了对矿物的捕收能力.     

PURIFICATION OF KAOLINS BY SELECTIVE DISPERSION AND FLOCCULATION

To fulfill the increasingly higher requirements on thequality of kaolins from industries, the purification of kaolins has becomemore and more important. Kaolins from different mines were studied withthe aim to remove the various impurities. The mineralogical studies on thekaolins indicated that kaolinite and the major gangue minerals in the orewere all very fine. Therefore, it was difficult to separate kaolinite fromthe gangue minerals by conventional mineral processing techniques,such asgravity concentration, magnetic separation and flotation. Techniques forfine particles processing, i. e. selective dispersion and flocculation weretried to purify the kaolins. The experiments were first carried out withpure minerals of kaolinite and the gangue,minerals to study the dispersionand flocculation characteristics of the different mineral suspensions undervarious conditions. The key factors affecting the dispersion and floccula-tion of the minerals in water were the pH of the suspension, the type anddosage of t     

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.     

Flotation of copper oxide minerals: A review

Copper oxide minerals are important copper resources, which include malachite, azurite, chrysocolla, cuprite, etc. Flotation is the most widely used method for the enrichment of copper oxide minerals in the mineral processing industry. In this paper, the surface properties of copper oxide minerals and their effects on the mineral flotation behavior are systematically summarized. The flotation methods of copper oxide minerals and the interaction mechanism with reagents are reviewed in detail. Flotation methods include direct flotation (using chelating reagents or a fatty acid as collector), sulfidization flotation (using xanthate as collector), and activation flotation (using chelating reagents, ammonium/amine salts, metal ions, and oxidant for activation). An effective way to realize efficient flotation of copper oxide minerals is to increase active sites on the surface of copper oxide minerals to enhance the interaction of collector with the mineral surface. Besides, various perspectives for further investigation on the efficient recovery of copper oxide minerals are proposed.     

我国一水硬铝石型铝土矿的矿物学研究

在我国一水硬铝石型铝土矿床中已查明矿物94种。其中钽铌铁矿等12种矿物在国外铝土矿中尚无报导。一水硬铝石是我国铝土矿的主要铝工业矿物,其结晶程度、粒度大小、比磁化系数和红外光谱的O-H键波数因矿床成因类型不同而异。研究表明,一水硬铝石的形成途径主要有三种:由高岭石直接脱硅而成;三水铝石经区域变质作用脱水而成;后生、表生条件由铝真溶液结晶而成。     

Flotation performance of a novel Gemini collector for kaolinite at low temperature

How to sustainably produce bauxite by effective reverse froth flotation of kaolinite at low temperature is an urgent problem to be solved in the field of mineral processing. In this work, a novel amino-based Gemini surfactant butadiyl-1, 4-bis (dimethyl dodecylammonium bromide) (BBDB) was prepared and first utilized as a novel collector for kaolinite flotation. Its flotation performance for kaolinite was compared with that of the common monomolecular surfactant 1-dodecylamine (DDA) by micro-flotation tests. The tests results indicated that 95% kaolinite recovery was obtained using 2.0 × 10⁻⁴ mol/L BBDB at 25 ℃, which was half of the dosage when DDA obtained the maximum kaolinite recovery of 81%. At extremely low temperature (0 ℃), 3.0 × 10⁻⁴ mol/L BBDB could still collect 91% kaolinite, while DDA showed a frustrating ability. The contact angle tests indicated that BBDB could still significantly improve the hydrophobicity of the kaolinite surface (contact angle 71.7°) than DDA (contact angle only 25.8°) at 0 ℃. The Krafft point comparison tests indicated that BBDB had a much lower Krafft point (below 0 ℃) than DDA. Fourier transform infrared spectroscopy (FTIR)-spectrum analysis and zeta potential measurements showed that BBDB was physically adsorbed on the surface of kaolinite through electrostatic interaction.     

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.     

辛基羟肟酸浮选行为的研究进展

羟肟酸是一类高效、低毒、选择性强的捕收剂,已被广泛应用于多种金属矿,特别是稀土矿物的浮选。其中,辛基羟肟酸（OHA）碳链长度适中,生产工艺简单且成本低,具有良好的浮选性能和起泡性能。介绍了OHA的合成方法、捕收机理、分析检测手段及其在稀土矿物、钨矿物、铁矿物、锡石、孔雀石等矿物浮选中的应用。OHA可通过络合作用与多种金属离子形成稳定的杂环螯合物,从而实现药剂在矿物表面的选择性吸附。OHA浮选pH范围较宽,pH为7左右浮选效果最佳。在抑制剂的作用下,OHA能实现稀土矿物、钨矿物等有价矿物与重晶石、萤石、石英等脉石矿物的有效分离。开发基于OHA 的组合药剂,有望获得更好的选别指标和经济效益。     

Study of the interfacial interactions in the molybdenite floatation system

Interfacial interactions involving Van der Waals force, hydrophobic attractive force and hydration exclusive force were investigated in this paper. The interfacial interactive free energy of a series of interfaces occurring between minerals, water, collectors and bubble was calculated. The results show that a Van der Waals attractive force and a hydrophobic attractive force exist between each mineral and water interface. The hydrophobic attractive force between molybdenite and water is markedly weaker than the hydrophobic attractive force between gangue and water. The hydrophobic attractive force between collector molecules and water is the main driving force that causes the collectors to become dispersed in the pulp. The strong hydrophobic attractive force between molybdenite and the bubble interface is the basic reason for the natural floatability of molybdenite. The Van der Waals force between molybdenite and the collectors is attractive in water solution, but it is not the cause of the main force between them. The main force that results in the collection effect is a hydrophobic attractive force caused by the Lewis acid-base interaction at the molybdenite surface. A floatation experiment shows that the adsorption intensity of the collector on the molybdenite surface is not the crucial factor for molybdenite floatation. Rather, the dispersing capability of the collector in the water phase and its selectivity for the various minerals in the floatation system are more important.