油酸钠对微细粒钛铁矿的捕收机理

以油酸钠为捕收剂,通过浮选实验、溶液化学计算、动电位和红外光谱检测研究了微细粒钛铁矿的可浮性及药剂与矿物的作用机理.结果表明:当油酸钠浓度为0.2 mmol/L时,微细粒钛铁矿可浮性较好的pH值为4～10.油酸钠对钛铁矿的捕收作用主要由两方面因素控制:当pH值为4～6时,以油酸根离子与钛铁矿表面铁质点间发生化学作用为主,红外光谱分析显示作用产物为油酸铁;当pH值为6～10时,上述化学作用减弱,但油酸钠溶液中高表面活性组分离子-分子缔合物浓度增大,使钛铁矿保持了较好的可浮性.     

表面溶解对微细粒钛铁矿与钛辉石浮选分离的影响

通过红外光谱(FT-IR)和X射线光电子能谱(XPS)分析,研究钛铁矿与钛辉石的表面溶解行为对其浮选分离的影响.实验结果表明,弱酸性条件下的表面溶解有利于提高钛铁矿与钛辉石的可浮性差异.在弱酸性条件下,由于钛铁矿与油酸钠的作用以Fe为主,而表面溶解有利于其在钛铁矿表面的氧化,使钛铁矿可浮性得到提高;同时,油酸钠与Ca和Mg的作用导致了钛辉石的可浮选,但表面溶解降低了钛辉石表面Ca和Mg的含量,使钛辉石可浮性明显下降.对于原矿TiO2品位为8.41%的攀枝花钛铁矿,经表面溶解处理后浮选可将粗选精矿TiO2的品位由26.7%提高到31.73%.     

钛辉石对钛铁矿浮选行为的影响

采用浮选实验和DLVO理论计算,研究钛辉石和钛铁矿各自的可浮性以及各粒级钛辉石对钛铁矿可浮性的影响规律及机理.浮选实验结果表明:钛铁矿具有很好的可浮性,钛辉石可浮性较差;粒径小于10 μm的钛辉石对钛铁矿回收率影响很大.DLVO理论计算结果表明:当pH=5.9时,两种矿物颗粒间的总相互作用能为负值,表现为相互吸引,微细粒级的钛辉石会在钛铁矿表面上粘附,使钛铁矿的回收率显著降低;当pH=8.5时,由于静电排斥能大,总相互作用能仍表现为较强的排斥力,微细粒钛辉石不能粘附在钛铁矿表面.     

油酸钠作用下异极矿的浮选行为及作用机理

通过纯矿物试验研究油酸钠为捕收剂体系中异极矿的浮选行为。结果表明:当油酸钠用量为3×10~(-4)mol/L、p H值为4~8和11时,异极矿浮选回收率均在80%左右。Zeta电位及红外光谱测试结果表明:油酸钠在异极矿表面主要发生化学吸附,同时也可能存在物理吸附。根据油酸钠溶液和锌离子水解组分含量化学计算,当p H值为4~8时,油酸钠溶液的优势组分为RCOO~-和(RCOO)_2~(2-);而异极矿表面锌离子主要以Zn~(2+)和少量Zn OH~+形式存在。结合异极矿在油酸钠捕收剂体系中的浮选行为,油酸钠在异极矿表面的相互作用原理是异极矿表面Zn~(2+)和羟基络合物Zn(OH)~+成为浮选的活性质点,能与油酸钠作用形成油酸盐,从而使异极矿疏水上浮;RCOOH_(aq)分子和离子-分子缔合物RCOOH·RCOO~-的物理吸附也可能存在;而在p H为11时矿物可浮性较好,可能是油酸根离子与矿物表面的形成Zn(OH)_2发生离子交换。     

钛铁矿在捕收剂1,10-菲罗啉作用下的浮选行为（英文）

引入1,10-菲罗啉(Phen)作为钛铁矿与钛辉石选择性分离的新型捕收剂。浮选实验表明,与苯甲羟肟酸(BHA)相比,在pH 2～12之间,Phen是钛铁矿浮选更加有效的捕收剂,并且在pH 6时钛铁矿的回收率提高最大(约为20%)。在浮选过程中,钛辉石的可浮性保持在非常低的水平(回收率<5%)。FTIR和XPS分析表明,Phen和BHA以化学吸附的方式吸附在钛铁矿表面,并且钛铁矿与Phen之间的相互作用比BHA更强。XPS结果还表明,Phen在钛铁矿表面与铁(亚铁和铁)和钛发生反应,在Phen吸附到钛铁矿表面的过程中形成五元环结构。     

8-羟基喹啉在微细粒铝硅矿物浮选分离中的作用

通过浮选实验、动电位和红外光谱测定,考查了8-羟基喹啉对一水硬铝石和高岭石浮选分离的作用及机理。单矿物浮选结果表明:8-羟基喹啉的捕收能力较弱,选择性差。人工混合矿分离实验结果表明:8-羟基喹啉用量是油酸钠用量的1/10或更小时,可以显著提高Al2O3精矿的回收率;其中油酸钠在较低用量水平时,8-羟基喹啉可基本保持原有的选择性,实现铝硅分离。动电位测试表明:8-羟基喹啉用量在0~5×10-4 mol/L范围内,在两个不同的油酸钠用量下,高岭石的ζ电位均随着8-羟基喹啉用量的增大而负移;而对于一水硬铝石而言,结果却不一样,这说明8-羟基喹啉在铝硅矿物表面吸附的模式可能不同。红外分析结果表明:8-羟基喹啉主要通过氢键作用和络合作用被吸附在矿粒表面,造成矿物表面的初步疏水,促进捕收剂对矿物的捕收。     

高砷微细粒金矿石浮选新工艺研究

在详细的工艺矿物学研究基础上,针对矿石性质采用高效活化剂FA－1＃和FA－2＃配合硫酸铜和水玻璃调浆,改善了高砷微细粒金矿的浮选条件,显著活化了载金硫化物和自然金的浮选。一段磨矿一粗二精三扫浮选流程,金回收率达到92．28％,比现厂提高回收率10个百分点。     

油酸钠作用下金红石的浮选行为及作用机理

通过纯矿物试验,研究金红石在油酸钠为捕收剂体系中的浮选行为。当油酸钠用量为20 mg/L、pH值为6~8时,金红石浮选回收率均在80%以上;当pH=7.5时,金红石浮选回收率最高,为85.27%。Zeta电位及红外光谱测试结果表明,油酸钠在金红石表面主要发生了化学吸附,同时也可能存在物理吸附。根据油酸钠溶液化学计算,当pH值为6~8时,油酸钠溶液的优势组分为C17H33COO-和(C17H33COO)22-;而金红石表面Ti4+的羟基化合物主要以[Ti(OH)2]2+和[Ti(OH)3]+形式存在。结合金红石在油酸钠捕收剂体系中的浮选行为,油酸钠在金红石表面的相互作用原理是,金红石表面解离的Ti4+在水溶液中形成羟基化合物[Ti(OH)2]2+和[Ti(OH)3]+络合在金红石表面成为浮选的活性质点,再与C17H33COO-和(C17 H33COO)22-作用形成Ti(C17H33COO)4,从而使金红石疏水上浮;油酸(C17H33COOH(aq))分子和离子-分子缔合物(C17H33COOH·C17H33COO-)的物理吸附也可能存在。     

油酸钠体系下HEDP对磷灰石与方解石浮选分离的影响

研究捕收剂油酸钠体系下HEDP(羟基乙叉二膦酸)抑制剂分离磷灰石与方解石的可行性,单矿物浮选试验表明,油酸钠对磷灰石和方解石均有较好的捕收性能,当pH值为9时,HEDP抑制剂能显著抑制方解石的浮选,而对磷灰石的抑制性能较小.人工混合矿浮选试验表明,HEDP抑制剂较好地实现了磷灰石与方解石的分选分离.Zeta电位测试结果...     

捕收剂苯乙烯膦酸酯在钛铁矿浮选中的吸附机理（英文）

采用捕收剂苯乙烯膦酸酯(SPE)提高钛铁矿浮选效率,揭示相关作用机理并建立吸附模型。单矿物浮选试验结果表明,SPE在钛铁矿浮选中表现出比传统苯乙烯膦酸(SPA)更强的捕收能力。Zeta电位测定结果显示,SPE和SPA都能使钛铁矿的Zeta电位负向移动,而SPE的作用效果比SPA更加明显,表明SPE在钛铁矿表面的吸附更强。X射线光电子能谱分析证实了SPA和SPE在钛铁矿的Fe/Ti位点上的化学吸附作用。前沿轨道理论分析结果表明,SPE的化学活性比SPA的高。局部态密度分析结果表明,两种捕收剂的PO—H基团可与钛铁矿的Ti/Fe原子相互作用,从而在钛铁矿表面生成一个稳定的四元环。捕收剂与(104)钛铁矿表面的结合模型显示,SPE的吸附能量高于SPA的。综上所述,SPE对钛铁矿浮选的捕收能力和作用效果均优于SPA的,具有在工业上替代SPA的潜力。     

Effectively enhancing recovery of fine spodumene via aggregation flotation

The effects of shear strength on aggregation flotation processes for fine spodumene(particle size less than 19 μm) were investigated in this study.Sodium oleate was used as a surfactant and collector.The shear strength was controlled by varying the agitation speed of a selfmade stirring apparatus.The aggregation process was studied by measuring the continuous transformations in the size distribution and shape of flocs.The results showed that as the shear strength increased,the distribution of fi...     

Combustion synthesis of fine TiFe series alloy powder by magnesothermic reduction of ilmenite

Fine TiFe series alloy powder was fabricated by magnesothermic reduction of ilmenite as main raw material. Adiabatic temperature of the FeTiO3-Mg system was studied through thermodynamic analysis. Meanwhile, the characteristics of TiFe series alloy were described by XRD, SEM and grading analysis. It is shown that combustion synthesis of the FeTiO3-Mg system can carry out due to its strong exothermic reaction through adiabatic temperature calculate. Ultrafine TiFe series alloy powder after leached for 5 h has reasonable phases and morphology with the particle distribution of 0.2 to 1 μm. It indicates that in-situ magnesothermic reduction of natural ilmenite is a feasible way to fabricate ultrafine powder with a relatively lower cost.     

Surface modification of ilmenite and its accompanied gangue minerals by thermal pretreatment: Application in flotation process

The effect of conventional thermal pretreatment on the surface properties of ilmenite and its accompanied gangue minerals was investigated using flotation experiments (microflotation and laboratory cell flotation), XRD, XPS and FT-IR analysis and zeta potential and contact angle measurements. After treatment at 600 °C for 25 min as optimal condition, the floatability of ilmenite is improved from 73.5% to 91% at a pH value of 6.3. As demonstrated by XRD and XPS analysis, under this pretreatment condition, the Fe³⁺ content increases by almost 16.5% without any phase decomposition and structural changes in ilmenite. FT-IR analysis and contact angle and zeta potential measurements give evidences that the improvement of ilmenite floatability can be related to the enhancement of collector adsorption and the formation of a more insoluble hydrophobic layer of ferric iron oleate. The ore flotation experiments show that the thermal pretreatment process without making a significant change in TiO₂ content of ilmenite concentrate enhances the TiO₂ recovery from 65.4% to 73.7%.     

烷基羟肟酸对细粒锡石的浮选及其溶液化学性质(英文)

采用烷基羟肟酸作为捕收剂对细粒锡石进行浮选,并对其溶液化学性质进行研究。结果表明,3种烷基羟肟酸在碱性条件下对细粒锡石有较好的捕收能力,且适宜的浮选pH随着捕收剂碳链的加长而升高。金属离子对锡石浮选的影响主要由矿浆pH决定,金属离子浓度对锡石浮选也有影响。计算基团电负性得出烷基羟肟酸作为锡石捕收剂的适合烷基碳链长度大约为7。由溶液的组分浓度对数分布图(lgc—pH)分析可知,捕收剂以分子-离子共吸附模式作用于矿物表面。动电位测试及红外光谱分析表明,吸附反应中涉及到电荷作用力、氢键力和络合作用力,其最终产物可以表示为锡石的O,O-五元环结构的螯合物。     

Kinetics of the oxidation of ilmenite

The oxidation of ilmenite (FeTiO₃) in air and dry oxygen was investigated over the temperature interval 600 to 970°C. Dense platelets of ilmenite crystals as well as powder samples of ilmenite were oxidized. The weight data were recorded employing a thermobalance. The oxidation kinetics of ilmenite platelets were parabolic except for the initial stages during which logarithmic kinetics were observed. For powder samples the logarithmic rate law was followed primarily. The logarithmic rate law was attributed to free penetration of oxygen through cracks and short-circuit paths. The activation energies associated with the logarithmic rate law were nearly one-half of those obtained from parabolic oxidation. The growth morphology of the products of oxidation of ilmenite was observed with a scanning electron microscope. The effect of growth morphology on the kinetics is discussed, and a probable reaction mechanism is suggested for the oxidation of ilmenite.     

微波辅助磨碎钛铁矿

研究微波加热对攀枝花钛铁矿磨矿性能的影响。微波辐射时间、微波功率密度和样品质量是磨矿过程的重要参数。将40g样品在微波功率1kW下辐射30s,然后进行水淬处理。SEM分析结果表明：经过微波辐射处理的钛铁矿在有用矿物和脉石间产生了裂纹,能够有效地促进矿物与脉石的解离。在随后的磁选实验中,经过微波辐射处理的钛铁矿的回收率从44%提高到72%。