新型螯合剂对一水硬铝石和铝硅酸盐矿物浮选行为的研究

合成了含有羧基和肟基的新型螯合捕收剂HCMT并研究其对一水硬铝石、高岭石和伊利石的浮选行为。单矿物浮选试验表明,该捕收剂对一水硬铝石、铝硅酸盐矿物的捕收能力差别较大,能有效分离一水硬铝石与铝硅酸盐矿物。通过动电位、红外光谱和电镜扫描(SEM)等研究了捕收剂对矿物的吸附机理,结果表明捕收剂在一水硬铝石表面可能是通过COOH、-NHOH与Al-O形成双环螯合物的化学吸附,而在高岭石、伊利石表面主要是物理吸附。     

Preparation and performance of 4-alkyl-4,4-bis(hydroxycarbamoyl) carboxylic acid for flotation separation of diaspore against aluminosilicates

The existed collector for the flotation of diasporic bauxite in China is poor in selectivity. To look for a collector with high selectivity and strong collecting capacity on the diaspore flotation, novel 4-alkyl-4,4-bis(hydroxycarbamoyl) carboxylic acids (ABHC) including 4,4-bis(hydroxycarbamoyl) dodecanoic acid (HCDA), 4,4-bis(hydroxycarbamoyl) tetradecanoic acid (HCTA), and 4,4-bis(hydroxycarbamoyl) hexadecanoic acid (HCHA) were designed and synthesized for the beneficiation of diasporic bauxite by selective flotation. The results of flotation experiments for the single minerals showed that by using these compounds as collectors, the pulp pH value has significant influence on their collecting performance as the floatability of diaspore varies sharply with its change. The appropriate pH value for the flotation of diaspore gets close to neutral condition at which diaspore presents good floatability while kaolinite and illite exhibit poor floatabilities. HCDA, HCTA, and HCHA, especially HCDA, show good selectivity for the flotation between diaspore and aluminosilicate around pH 7. A satisfactory mass ratio of Al₂O₃ to SiO₂ (A/S) and recovery of Al₂O₃ were obtained from the flotation separation of artificially mixed minerals and the flotation desilication of diasporic bauxite by using HCDA as a collector, proving that the selectivity of HCDA is better than that of the traditional collector oleate. Moreover, adsorption amount, zeta-potential, DFT calculation, XPS, and FTIR were performed to study the mechanisms. The results indicated that the adsorption of HCDA on the surface of diaspore is dominantly chemisorption in the form of three chelate rings. The oxygen atoms contained in carboxyl and hydroxycarbamoyl of the polar group have the highly negative charges and stereo conditions to form five- to eight-membered ring, resulting in the coordination of carboxyl and hydroxycarbamoyl to the metal aluminum atoms to form chelate rings. By contrast, the adsorption of HCDA on the surface of kaolinite or illite is mainly physical adsorption.     

特戊羟肟酸的合成及其对铝硅矿物的浮选性能研究

采用羟胺法合成了特戊羟肟酸, 并研究了其对铝硅矿物的浮选行为及作用机理。单一捕收剂浮选一水硬铝石时, 特戊羟肟酸的浮选效果优于苯甲羟肟酸; 将特戊羟肟酸和油酸钠按1∶1进行复配, 浮选研究结果表明, 复配捕收剂既能提高一水硬铝石的回收率, 又能降低伊利石和高岭石的回收率, 具有更好的选择性; pH=7, 复配捕收剂浓度60 mg/L时, 一水硬铝石回收率可达86.8%。通过接触角、Zeta电位和红外光谱分析等对捕收剂与矿物表面的作用机理进行了探究, 发现油酸钠在一水硬铝石表面主要进行物理吸附, 而特戊羟肟酸主要为化学吸附, 二者复配能更有效地与一水硬铝石作用。     

季铵盐捕收剂对铝硅矿物的浮选行为

通过单矿物浮选试验、动电位测定及红外光谱分析研究了十二烷基三甲基氯化铵、十六烷基三甲基溴化铵和十八烷基二甲基苄基氯化铵3种季铵盐捕收剂对铝硅矿物一水硬铝石、高岭石、叶蜡石和伊利石的浮选行为和作用机理.结果表明:在碱性条件下,以季铵盐为捕收剂可实现一水硬铝石与3种硅酸盐矿物的反浮选分离;一水硬铝石、高岭石、叶蜡石及伊利石的等电点分别为pH6.0、3.4、2.3、3.2,随着矿浆pH值提高,这些矿物的表面动电位均呈负增加;季铵盐捕收剂主要靠静电作用吸附在一水硬铝石、高岭石、叶蜡石及伊利石表面.     

氧肟酸高分子药剂在铝土矿反浮选中的作用

通过浮选试验，研究了氧肟酸淀粉和氧肟酸聚丙烯酰胺两种高分子药剂对铝土矿中一水硬铝石和高岭石浮选行为的影响。结果表明：氧肟酸淀粉在酸性条件下对一水硬铝石有较强的抑制作用，而对高岭石有活化现象；氧肟酸聚丙烯酰胺在整个试验pH值范围内对两种矿物均有活化作用。两种大分子药剂属于阴离子型，动电位测定结果表明，它们在带负电的高岭石、一水硬铝石表面吸附，使其动电位负性增加，表明药剂与矿物存在氢键力或化学作用力。由于在一水硬铝石表面，氧肟酸淀粉可以罩盖捕收剂十二胺，增加矿物表面的亲水性，从而对其产生抑制作用。而线型氧肟酸聚丙烯酰胺在矿物表面为卧式吸附，其分子链上的负电区能够增加阳离子捕收剂的吸附量，从而活化了一水硬铝石的浮选。     

The behavior of N,N-dipropyl dodecyl amine as a collector in the flotation of kaolinite and diaspore

The flotation behaviors of kaolinite and diaspore were investigated using N,N-dipropyl dodecyl amine (PN). Maximum recoveries of kaolinite and diaspore were about 90% and 50%, respectively. Both recoveries of kaolinite and diaspore increased with the increasing dosage of PN. On the basis of the zeta potential and FT-IR spectra, the ionization of surface hydroxyl and the isomorphic exchange of surface ions account for the charging mechanisms of surfaces of kaolinite and diaspore. The adsorption mechanism of PN on the surface of two minerals was mainly electrostatic. After reacting with PN, the zeta potential of kaolinite and diaspore both increased, and comparing with the original zeta potentials, potential of kaolinite increased much more than that of diaspore, this can explain why recovery of kaolinite is higher than that of diaspore.     

捕收剂CTAB对一水硬铝石与高岭石的浮选差异及其分子动力学模拟

为了研究季铵盐类捕收剂对铝土矿反浮选的影响,以十二胺（DDA）为参照捕收剂,考察了十六烷基三甲基溴化铵（CTAB）对一水硬铝石和高岭石浮选回收率的影响,并通过FTIR分析、Zeta电位检测、吸 附量测定以及分子动力学模拟对作用机理进行了系统的分析。浮选试验结果表明,CTAB浮选分离效果优于DDA,在pH=4、CTAB浓度为2×10-4 mol/L时,纯矿物浮选试验一水硬铝石和高岭石浮选回收率相差51.70个百分 点,人工混合矿试验获得了Al2O3品位71.73%、回收率71.26%、SiO2含量9.43%的精矿,铝硅比A/S达到7.60。机理分析结果表明,捕收剂CTAB在一水硬铝石和高岭石表面均有吸附,在高岭石表面的吸附量大于在一水硬 铝石表面的吸附量,且均为物理吸附;分子动力学模拟计算结果表明捕收剂CTAB与高岭石总相互作用能为与一水硬铝石总相互作用能的2.29倍,因此CTAB分子优先吸附于高岭石的表面,具有较高的选择性,有利于反 浮选的进行。     

新型阳离子有机硅QAS222对铝硅矿物浮选行为的研究

考察了自行合成的新型有机硅阳离子表面活性剂QAS222对一水硬铝石、高岭石、叶蜡石和伊利石等4种铝硅矿物的浮选行为,并以其为铝硅酸盐矿物的捕收剂,进行了不同铝硅比的人工混合矿反浮选分离脱硅试验研究。试验研究结果表明,新型阳离子有机硅季铵盐类化合物是铝土矿反浮选脱硅的有效捕收剂;酸性条件下QAS222对一水硬铝石、高岭石、叶腊石和伊利石表现较好的捕收力,但此时反浮选分离趋势不明显;而在碱性条件下,以QAS222为捕收剂,随着矿浆pH值的上升,4种矿物的可浮性出现了不同程度的减低,尤其是当矿浆pH9后,一水硬铝石的上浮率骤减,铝硅矿物之间表现出了良好的反浮选分离趋势;在矿浆pH值为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。     

Role of crystal structure in flotation separation of diaspore from kaolinite,pyrophyllite and illite

Wettability and electrokinetics of kaolinite, illite, pyrophyllite and diaspore were measured in the context of reverse flotation using cationic collectors. The results were interpreted by crystal structure analysis of the minerals. The point of zero charge (PZC) was calculated using crystallographic parameters of the minerals and compared well with the corresponding iso-electrical point (IEP) determined experimentally. The decreasing order of the measured IEP or calculated PZC from diaspore to kaolinite, illite and finally pyrophyllite correlated well with decreasing the number of broken Al–O bonds and the ratio of broken Al–O to Si–O bonds. The electrostatic interaction was identified as the main driving force for cationic collector adsorption on the minerals. Satisfactory separation of aluminosilicates from diaspore was achieved by reverse flotation.     

铝土矿浮选新型捕收剂的捕收性能及机理研究

通过一水硬铝石和高岭石的单矿物浮选试验、接触角、红外光谱、和ζ电位测量分析了东北大学研制的DJL-1和DJL-2捕收剂在铝土矿正浮选中的浮选行为和作用机理。一水硬铝石与DJL-1和DJL-2作用后接触角变大、疏水性变强;高岭石与DJL-1作用后接触角几乎不变,与DJL-2作用后接触角变大。DJL-1使一水硬铝石和高岭石表面ζ电位均负向增加,DJL-2对一水硬铝石和高岭石表面ζ电位影响较小,分别使用DJL-1和DJL-2,一水硬铝石和高岭石的最大回收率之差为54.5%和70.5%,DJL-2在更宽的温度和pH范围内获得更好的浮选结果;DJL-1和DJL-2在一水硬铝石表面存在键合吸附和氢键作用,DJL-1与高岭石表面存在氢键作用。结果表明,DJL-1和DJL-2均是铝土矿正浮选的优良捕收剂,且DJL-2更优。     

A novel surfactant 2-amino-6-decanamidohexanoic acid: Flotation performance and adsorption mechanism to diaspore

In this paper, a novel surfactant, 2-amino-6-decanamidohexanoic acid (AHA-10) was synthesized and used as a collector for flotation separation of diaspore and aluminosilicate minerals. The adsorption mechanism of AHA-10 onto diaspore was also evaluated by FTIR spectra, zeta potential, XPS and solution chemistry. The flotation results demonstrated that AHA-10 exhibited superior collecting power to diaspore and good selectivity against kaolinite and illite, and could effectively recover diaspore from bauxite ores contained aluminosilicate minerals at pH around 10. The analyses of FTIR spectra, zeta potential and solution chemistry inferred that at pH around 10, AHA-10 might chemisorb on diaspore surfaces by formation of AlO and AlN bonds. AHA-10’s unique properties, such as characteristic bond model to Al atoms on diaspore surfaces, double hydrophobic groups and intermolecular hydrogen bonds between neighboring AHA-10 molecules coated on diaspore surfaces, rendering a weakening surface energy and enhancing hydrophobicity of diaspore particles.     

Selective depression of diaspore with waxy maize starch

Highly branched waxy maize starch (WMS) was used to separate diaspore from artificial mixtures of diaspore and kaolinite by microflotation using dodecylamine (DDA) as collector. It was found that WMS depressed the diaspore flotation while activated the kaolinite flotation more or less. The adsorption of WMS on diaspore was examined through adsorption test, zeta potential measurement, infrared spectroscopy, and atomic force microscopy. It is suggested that both chemical interaction and intermolecular hydrogen bonding by hydroxyl groups of starch with surface Al–OH moieties occurred in the adsorption. Results obtained from the adsorption of DDA and WMS on diaspore showed that starch virtually enhanced the DDA adsorption. The depressant action of WMS can be rationalized primarily by the formation of hydrophilic adsorption layer enveloping the surface of diaspore and covering the collector.     

烷基羟肟酸与一水硬铝石作用的密度泛函研究

基于密度泛函理论,研究了非极性碳链长度对烷基羟肟酸性质和一水硬铝石作用的影响。结果表明,相比于庚基、辛基和壬基羟肟酸,癸基羟肟酸阴离子最为活跃,反应活性最高,且两个O原子给电子能力突出。在(010)表面的形成过程中,一水硬铝石晶体结构中的Al—O和Al—OH键发生断裂,使表面上的Al和O原子成为易被捕收剂附着的位点。借助分子动力学模拟构建了几种羟肟酸在一水硬铝石(010)面的吸附模型,几种羟肟酸均能稳定吸附在一水硬铝石表面,由于羟肟酸极性基中两个O原子带大量负电荷,它们容易与表面Al离子形成环状螯合物,癸基羟肟酸表现出最强的捕收能力。理论计算结果与试验结论一致,密度泛函理论和分子动力学模拟能够辅助浮选药剂分子设计。     

Beneficiation of diasporic-bauxite ore by selective flocculation with a polyacrylate flocculant

Beneficiation of a diasporic-bauxite ore by selective flocculation with sodium polyacrylate (PAS) was studied. Flocculation behaviors of diaspore, kaolinite, illite and pyrophyllite in the presence of PAS were also investigated by sedimentation tests. PAS shows good selectivity for the flocculation separation of diaspore from silicates in the range of pH 8–12. A concentrate with Al₂O₃/SiO₂ ratio 8.9 and the recovery of Al₂O₃ 87.0% was obtained from a diasporic-bauxite ore with Al₂O₃/SiO₂ ratio 5.7 with the addition of sodium carbonate 5 kg/t and PAS 7 g/t. Micro-photogram, zeta potential and FTIR measurements were then performed to study the mechanisms. It was observed that the zeta potentials of diaspore shifted to negative value strongly and the isoelectric point (IEP) of diaspore was also changed from about pH 6–4, and the flocs of diaspore were larger and denser than that of kaolinite in the presence of PAS. A new band at 1640 cm⁻¹ was found in the infrared spectrum of the diaspore after interaction with PAS, and this new band matched the characteristic peak at 1624 cm⁻¹ in the infrared spectrum of the reaction products of PAS and AlCl₃. The adsorption of PAS on diaspore is concluded to be chemisorption caused by the chemical reaction between carboxylate group and the exposed Al sites on diaspore surface.     

选择性抑制剂BK501A在铝土矿反浮选脱硅中的应用

通过浮选试验、絮凝试验、动电位和红外光谱测定,详细考察了抑制剂BK501A在一水硬铝石与高岭石反浮选分离中的作用效果和机理。浮选试验表明,通过加大药量,一水硬铝石在广泛的pH范围内被抑制,而对高岭石的可浮性影响很小。机理分析表明,药剂通过氢键与一水硬铝石强烈作用,产生亲水性絮凝,从而使其被抑制。     

钙离子对铝土矿选择性絮凝的影响及消除的试验研究

采用沉降试验方法, 研究了钙离子对一水硬铝石、高岭石、伊利石和叶腊石单矿物分散性能的影响规律。结果表明, 碱性条件下, 钙离子对矿物的分散性影响较大, 一水硬铝石、高岭石和叶腊石的聚沉十分明显, 原来的分散体状态被破坏。虽然采用碳酸钠和三聚磷酸钠均可消除体系中的钙离子, 但单矿物和实际矿石试验结果均表明, 三聚磷酸钠是硬水体系下的良好调整剂, 在消除了钙离子影响的同时, 可得到与软水条件下相同的分离效果和指标。在碱性条件下, 一羟基钙络合物和氢氧化钙沉淀在矿物表面的吸附造成了矿物颗粒间的凝聚。碳酸钠主要与钙离子反应生成碳酸钙沉淀, 而三聚磷酸钠则与钙离子形成稳定的环状内络物(螯合物), 从而消除了钙离子的聚沉作用。     

调整剂在浮选分离一水硬铝石和高岭石中的研究

单矿物浮选试验结果表明, 在阳离子捕收剂DTAL 作用下, 调整剂SFL 在pH=2～12 范围内活化高岭石的浮选, 而在弱酸性条件下对一水硬铝石的浮选影响较小。弱酸性条件下的人工混合矿分离试验表明, 随着原矿中一水硬铝石的含量的增加, 精矿铝硅比显著上升, 氧化铝的回收率也随着提高;在调整剂SFL 的作用下, 精矿铝硅比进一步提高。动电位测试研究表明, 与SFL 作用后的一水硬铝石和高岭石的负电位显著增加, 使得阳离子捕收剂通过静电作用力更容易吸附在矿物表面上吸附。吸附量的测试表明:SFL增加了在高岭石表面的捕收剂吸附量, 而在一水硬铝石表面的捕收剂吸附量有所减少。     

一水硬铝石和含铝硅酸盐矿物在不同调整剂作用下的浮选行为研究

主要考察了以1228作为捕收剂,一水硬铝石和含铝硅酸盐矿物在甲基纤维素、Na2SiF6、SA3、1230和1231等五种调整剂作用下的浮选行为。结果表明,调整剂SA3、1230和1231对一水硬铝石都有抑制作用,但1230和1231对含铝硅酸盐矿物也有不同程度的抑制作用,尤其是对伊利石的抑制作用比较强;甲基纤维素对一水硬铝石和含铝硅酸盐矿物都有很强的抑制作用;调整剂Na2SiF6只有在pH<2.0的条件下才对一水硬铝石显示较强的抑制作用,而且浮选的pH值范围窄。通过对几种调整剂作用进行分析比较,酸性介质中SA3有可能实现一水硬铝石与含铝硅酸盐矿物的选择性分离。     

黏土中层状硅酸盐矿物对聚羧酸减水剂的吸附

采用凝胶渗透色谱分析和比较了高岭土、伊利土、蒙脱土对聚羧酸减水剂(PCE)的吸附量。结果表明,蒙脱土对PCE有强吸附作用。当PCE为2.00 g/L的标准掺量时,蒙脱土的吸附量为7.18 mg/g,而高岭土和伊利土的吸附量仅为2.01 mg/g和4.59 mg/g。并且蒙脱土的吸附量随PCE质量浓度的增大和温度的提高而快速增大。碱性条件3种矿物的吸附量减小,其中蒙脱土表现尤为明显。体系中Ca~(2+)、Mg~(2+)特别是Mg~(2+)的存在会明显增大蒙脱土对PCE的吸附量,但对高岭土和伊利土的吸附量没有明显影响。     

铝土矿脱硅浮选药剂的应用及研究

概述了铝土矿浮选脱硅药剂的应用现状及抑制剂作用机理 ,分析了一水硬铝石、高岭石、叶腊石和伊利石的晶体结构和表面性质 ,并针对不同的一水硬品石型铝土矿浮选脱硅工艺 ,提出了有机抑制剂的研制思路与要点