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。     

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...     

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。     

QAX224捕收剂反浮选分离一水硬铝石和高岭石的试验研究

通过浮选试验、动电位和红外光谱测定,考察了以季铵盐QAX224为捕收剂,淀粉为抑制剂,一水硬铝石与高岭石反浮选分离的作用效果和机理。浮选试验表明, 在pH=8～9的范围内,随着抑制剂用量的增加,一水硬铝石几乎全部被抑制,而高岭石则可出现轻微的活化作用。将一水硬铝石和高岭石的人工混合矿反浮选试验后,铝硅比提高到30.79。机理分析表明,捕收剂和抑制剂与高龄石除了物理作用,还出现了化学键合,一水硬铝石与捕收剂主要为静电吸附,与淀粉主要是化学吸附。     

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.     

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。     

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。     

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。     

铝土矿反浮选脱硅中BK5O1抑制剂的研制与应用

通过浮选试验,EDS、动电位和红外光谱测定,考察了BK501抑制剂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,通过药量加大,一水硬铝石几乎全部被抑制,而高岭石则可出现轻微的活化作用.最终分选指标:不脱泥,将一水硬铝石:高岭石=2:1的人工混合矿反浮选,槽内产品Al203回收率77.59%,铝硅比10.74.脱泥后,槽内产品Al2O3回收率80.12%,铝硅比10.79.机理分析表明,药剂与一水硬铝石除氢键作用外,还出现了强烈的化学键合,对高岭石产生絮凝作用而显现活化上浮.     

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。     

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.     

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.     

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.     

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。     

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。