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.     

烷基胍浮选铝硅酸盐矿物的研究

以O-甲基异脲硫酸盐和脂肪胺为原料,常压下合成了烷基胍类捕收剂.考查了它们对一水硬铝石、高岭石、叶蜡石及伊利石的浮选行为.烷基胍对铝硅酸盐矿物的捕收能力和选择性优于十二胺和十二烷基三甲基氯化铵.在强碱性条件下,高岭石、叶蜡石及伊利石较一水硬铝石有很好的可浮性,以烷基胍为捕收剂可望实现三种硅酸盐矿物与一水硬铝石的反浮选分离.通过药剂结构和矿物表面电性研究解释了捕收剂与矿物作用的机理.     

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。     

一水硬铝石与高岭石、叶蜡石和伊利石浮选分离中晶体结构的作用

测量了高岭石、伊利石、叶蜡石和一水硬铝石在阳离子捕收剂反浮选时的润湿性和动电行为。通过分析矿物的晶体结构,对测量结果进行了解释。根据矿物的晶格参数计算了矿物的零电点,计算的零电点值与试验测得的等电点值有很好的吻合。等电点测量值和零电点计算值的减小顺序为:一水硬铝石>高岭石>伊利石>叶蜡石,这与Al-O断裂键数目以及Al-O断裂键数目与Si-O断裂键数目的比值减小顺序基本一致。阳离子捕收剂在矿物表面上的吸附作用主要为静电作用。反浮选分离含铝硅酸盐矿物和一水硬铝石获得了满意的结果。     

BK430在铝土矿反浮选脱硅中的应用

考察了以BK430作为捕收剂对中国铝土矿资源中一水硬铝石、伊利石和高岭石3种典型矿物的浮选行为。单矿物试验结果表明:在不添加抑制剂和弱酸性条件下,BK430对高岭石和伊利石的捕收力明显强于一水硬铝石;添加一水硬铝石抑制剂DF,有助于进一步扩大一水硬铝石与2种铝硅酸盐矿物的可浮性差异;人工混合矿的试验结果与单矿物试验结果比较吻合。对河南某铝硅比为4.43的铝土矿进行了反浮选脱硅试验,经过脱泥—反浮选可以获得Al2O3/SiO2为9.21,Al2O3回收率为62.49%的精矿。BK430有望成为一种在近中性条件下铝土矿反浮选的脱硅捕收剂。     

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。     

C01和B01等药剂在铝土矿反浮选中的应用

考察一水硬铝石、高岭石和伊利石在不同pH条件下,以四种药剂作为捕收剂的单矿物浮选行为.结果表明,C01和B01对铝硅酸盐矿物的捕收能力较强,且最有希望在近中性条件下作为铝土矿反浮选的捕收剂.     

氟化钠在铝硅酸锌矿石物浮选新工艺试验研究

在季铵盐捕收剂体系中，氟化钠活化了层状硅酸盐矿物高岭石、伊利石和叶蜡石的浮选，而对一水硬铝石的浮选没有影响，可以作为铝土矿反浮选的有效调整剂。氟化钠在矿物表面上发生特性吸附作用，显著降低硅酸盐矿物的Zeta电位，而对一水硬铝石的电位影响不大。AES研究表明，氟离子扩散至硅酸盐矿物颗粒内部，使得其在硅酸盐矿物颗粒上的吸附量很高，而只在一水硬铝石表面发生较低量的吸附。氟离子在硅酸盐矿物颗粒的表面和内部的高吸附量显著降低矿物的动电位，增强捕收剂与矿物的静电作用，从而起到活化作用。     

聚丙烯酰胺类抑制剂对一水硬铝石和高岭石可浮性差异调控的影响

针对捕收剂在一水硬铝石与高岭石表面的吸附选择性较差的问题,添加3种不同类型的聚丙烯酰胺抑制剂调变捕收剂在矿物表面的选择性吸附差异,研究抑制剂类型对捕收剂丙撑基双十二酰胺丙基二甲基氯化铵(DAPDPAC)在矿物表面的吸附量差异和相互作用变化,以及抑制剂对两种矿物的浮选影响。浮选试验结果表明:与非离子聚丙烯酰胺(NPAM)和阴离子聚丙烯酰胺(APAM)相比,阳离子聚丙烯酰胺(CPAM)显示了捕收剂对两种矿物显著的浮选调变差异,且CPAM在浓度80 mg/L时,一水硬铝石的回收率受到明显抑制,而高岭石的回收率几乎不变,且在酸性至弱碱性环境下,可以较好地实现一水硬铝石和高岭石的浮选分离。红外光谱测试结果表明:添加的抑制剂CPAM有效地阻碍了DAPDPAC在一水硬铝石表面的吸附,而在高岭石表面的吸附无明显变化。吸附量、Zeta电位及XPS测试结果表明:CPAM用量大于80 mg/L时,DAPDPAC在一水硬铝石和高岭石表面的吸附量差值保持在9.76×10-7 mol/g以上。因此,CPAM可有效调控DAPDPAC在一水硬铝石和高岭石表面的选择性吸附,有利于强化DAPDPAC对一水硬铝石和高岭石的...     

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。     

Synthesis and collecting properties of novel carboxyl hydroxamic acids for diaspore and aluminosilicate minerals

Novel carboxyl hydroxamic acids compounds, including 2-carboxyl-6-methylcyclohexane carboxamic acid (CMCA), 2-carboxymethyl-decylen-4-yl hydroxamic acid (CDHA), and 2-carboxymethyl-tetradecen-4-yl hydroxamic acid (CTHA) were synthesized, and the flotation behaviors of diaspore, kaolinite and illite were investigated by using these compounds as collectors. The adsorption mechanism of CTHA on the surface of diaspore, kaolinite and illite was conducted by zeta-potential, adsorption amount and FTIR spectra measurement. The interaction of CTHA on the diaspore surface may be mainly dominated by the chemical adsorption; however, the adsorption of CTHA on kaolinite or illite is mainly dominated by the physical one.     

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.     

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.     

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.     

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。     

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。     

Utilization of soluble starch as a depressant for the reverse flotation of diaspore from kaolinite

The utilization of a non-toxic natural polysaccharide, soluble starch, in the flotation of diaspore and kaolinite with emphasis on depression of diaspore in the reverse flotation of bauxite ores by using a Gemini cationic collector, is reported in this work. Firstly, the depressant effect of soluble starch was studied by pure mineral micro-flotation of diaspore and kaolinite as functions of the depressant dosage and pulp pH. The results show that soluble starch depresses diaspore much better than kaolinite. When pH is over 10, a satisfactory separation of the alumina and the silicate minerals can be approached. Moreover, micro-flotation tests of artificial mixed minerals and bench scale reverse flotation of the diasporic bauxite ore was complementing conducted. The non-charged starch is highly proved to be an effective and selective depressant for the reverse flotation of diaspore from the gangue minerals like kaolinite. By zeta potential measurement, adsorption studies and D-IR spectra analysis, the mechanism of interaction between starch and the diaspore surfaces is established, which is the formation of a five membered ring complexes on mineral substrates. The number of broken Al–O bonds of diaspore is much more than that of kaolinite, so the selectivity separation of diaspore from kaolinite in this system is feasible.