一水硬铝石和高岭石可浮性的晶体化学分析

从一水硬铝石和高岭石的晶体结构的特征出发,通过对一水硬铝石和高岭石结构中化学键的理论计算及阴离子捕收剂（油酸钠）阳离子捕收剂（十二胺）浮选体系中可浮性的研究,采用矿物晶体化学理论分析了矿物晶体结构特征与可浮性之间的关系,以及产生一水硬铝石和高岭石了性差异的主要原因。     

阳离子聚丙烯酰胺反浮选分离一水硬铝石和高岭石

在分析一水硬铝石和高岭石的晶体结构以及表面性质差异的基础上，通过单矿物实验、人工混合矿实验、ξ—电位和吸附量研究，找到一水硬铝石的有效抑制剂阳离子聚丙烯酰胺。在pH为5．5—8．5的范围内，实验了以十二胺醋酸盐为捕收剂时高岭石和一水硬铝石的反浮选分离。一水硬铝石表面活性Al原子数量多，易与酰胺基团结合，导致阳离子聚丙烯酰胺中的季铵基团定向排列在一水硬铝石表面的外面，阻止大部分十二胺阳离子吸附在其表面，并增大一水硬铝石的亲水性，抑制了一水硬铝石的上浮。而阳离子聚丙烯酰胺对十二胺浮选高岭石影响很小。     

阳离子捕收剂反浮选——水硬铝石型铝土矿研究

以十二胺醋酸盐为捕收剂,ＳＡ３为抑制剂,研究了一水硬铝石、高岭石及叶腊石的反浮选分离,结果表明,在pＨ＝６－８的范围内,ＳＡ３与十二胺醋酸盐组合,能抑制９０％以上的一水硬铝石的浮出,而高岭石与叶蜡石的上浮率大于８０％。作为一水硬铝石的高效抑制剂,ＳＡ３还具有用量少、适用性强、选择性高等特点。     

二元组合捕收剂浮选分离一水硬铝石与高岭石的机理研究

以油酸钠为主要捕收剂,与苯甲羟肟酸组合使用,复配出二元组合捕收剂,再通过单矿物浮选试验考察二元组合捕收剂对一水硬铝石和高岭石两种铝硅矿物的捕收性能。通过表面张力测定和激光粒度测试,系统研究了二元组合捕收剂的浮选作用机理,旨在为我国铝土矿浮选脱硅捕收剂的开发提供理论指导。结果发现,二元组合捕收剂NaOL/BHA对一水硬铝石和高岭石伴生的铝硅酸盐矿物的浮选效果明显超过单一油酸钠捕收剂,研究的二元组合捕收剂中油酸钠与苯甲羟肟酸的最佳摩尔配比为9∶1。二元组合捕收剂溶液的表面张力随着BHA浓度的增加而下降,在较低浓度下表面张力明显下降到拐点达到稳定值,该现象表明组合捕收剂活性高,捕收性能强,拐点处对应的两种药剂摩尔配比与单矿物浮选实验得出的最佳组合摩尔比一致。二元组合捕收剂可以明显促进一水硬铝石颗粒表观粒度增大,使其形成疏水性聚团,致使浮选回收率增大,而对高岭石表观粒度几乎没有影响。     

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。     

阴离子捕收剂浮选一水硬铝石溶液化学机理

利用激光动电位测定一水硬铝石的等电点为pH =6 2。用阴离子捕收剂十二烷基磺酸钠和油酸钠浮选一水硬铝石 ,十二烷基磺酸钠与一水硬铝石以静电作用为主 ,并发生半胶束吸附 ,最佳浮选范围为pH <6 2 ;而油酸钠浮选一水硬铝石时为化学吸附 ,当油酸钠浓度为 1× 10 - 4 mol L时 ,一水硬铝石最佳浮选范围为pH =5～ 9。溶液化学计算得到的油酸钠浮选一水硬铝石的pH值上限和下限与试验结果一致。红外光谱分析证明油酸钠在一水硬铝石表面发生了化学吸附     

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.     

阴离子捕收剂浮选—水硬铝石溶液化学机理

利用激光动电位测定一水硬铝石的等电点为pH=6.2。用阴离子捕收剂十二烷基磺酸钠和油酸钠浮选一水硬铝石,十二烷基磺酸钠与一水硬铝石以静电作用为主,并发生半胶束吸附,最佳浮选范围为pH<6.2;而油酸钠浮选一水硬铝石时为化学吸附,当油酸钠浓度为1×10     

一水硬铝石的表面粘附能研究

采用扫描电子显微镜和原子力显微镜分析了一水硬铝石的表面形貌, 并利用原子力显微镜对捕收剂作用前后一水硬铝石的单位面积粘附能进行了定量分析。一水硬铝石矿物{010}解理存在大量高度为12 nm左右的解理台阶, 在(010)解理面上可观察到大量晶体生长小丘, 因此增大了一水硬铝石颗粒的表面活化点数目和比表面积。通过对一水硬铝石矿物进行了力-位移曲线测定分析, 定量地计算出一水硬铝石分别经蒸馏水、十二胺、油酸钠溶液浸泡之后其(010)面的平均粘附力和单位面积上平均粘附能的大小顺序分别为: F_蒸馏水>F_十二胺>F_油酸钠和W_蒸馏水>W_十二胺>W_油酸钠; 可见, 经捕收剂作用之后, 一水硬铝石由高能表面变为低能表面。     

一水硬铝石与高岭石反浮选分离研究

详细研究了一水硬铝石和高岭石的浮选行为 ,并以十二胺盐酸盐作为捕收剂 ,在酸性介质 ( pH3 .5 )及中性介质 ( pH7.5 )加调整剂ATNO进行反浮选分离研究 ,得到较好的分离效果 ,精矿A/S >11。同时进行了不同粒级和不同A/S的一水硬铝石和高岭石的反浮选分离 ,结果表明 ,不同的A/S条件下 ,可以得到较好的分离效果 ,但粒级对一水硬铝石和高岭石的分离有较大的影响 ,细粒级一水硬铝石与高岭石分离效果不好 ,有待于进一步研究     

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 exa...     

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。     

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。     

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.     

Flotation of aluminosilicates using N-(2-aminoethyl)-1-naphthaleneacetamide

The present work deals with the flotation behavior of kaolinite, illite and pyrophyllite with N-(2-aminoethyl)-1-naphthaleneacetamide (AENA). The best recoveries of kaolinite, illite and pyrophyllite were 41.4%, 39.8% and 90.4% respectively. The flotation behavior of three aluminosilicates is almost independent of pulp pH and the collector concentration. The results obtained show that AENA is a stronger collector for pyrophyllite. Conversely it is weaker for kaolinite and illite. By determining the effects of pulp pH on the zeta potential of aluminosilicates, we found that along with the rise in pulp pH, the zeta potential of the aluminosilicate pulp changed gradually from the plus zone to the minus zone. However, there is not a marked change in the floatability of the aluminosilicates. It was shown that the interaction between the collector and the surfaces of the ore particle was not merely electrostatic force, there are also probably hydrogen bonds between them.     

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。     

铝土矿浮选的抑制剂研究

主要研究了油酸钠作捕收剂，草酸钠、水杨酸钠等四种小分子有机调整剂对一水硬铝石、叶蜡石、高岭石三种单矿物的作用。结果表明，草酸钠、柠檬酸钠对高岭石和一水硬铝石有抑制作用，水杨酸钠、乳酸钠只对高岭石有抑制作用，四种调整剂对叶蜡石可浮性均无影响。