菱铁矿和白云石对石英浮选的影响

通过浮选试验、吸附量测定和溶液化学计算研究了油酸钠浮选体系下菱铁矿和白云石对石英浮选的影响.浮选试验和吸附量测定结果表明:菱铁矿对石英浮选的影响与其溶解组分有关,当淀粉存在时,菱铁矿可显著影响石英浮选;白云石的溶解组分对石英浮选的影响较小,增大油酸钠用量可在一定程度上消除白云石的影响.溶液化学计算表明,菱铁矿的溶解组分可将活化的石英表面转化为易被淀粉抑制的CaCO_3沉淀,而白云石的溶解会受到浮选体系中钙离子的抑制,这也是菱铁矿和白云石溶解对石英浮选的影响存在差异的主要原因.     

细粒菱铁矿、石英和赤铁矿吸附团聚的机理

含菱铁矿难选铁矿石在磨矿作业过程中,菱铁矿极易泥化,并大量吸附在脉石和有用矿物的表面上,恶化了后续选别作业.为了查明微细粒菱铁矿、石英和赤铁矿在矿浆中吸附团聚的本质及规律,利用DLVO理论探讨了微细粒菱铁矿与粗粒石英、微细粒菱铁矿与赤铁矿及细粒菱铁矿之间的作用机理.计算结果表明:微细粒菱铁矿容易吸附罩盖在粗粒石英和赤铁矿表面,微细粒菱铁矿和微细粒赤铁矿相互作用发生团聚现象,而微细粒菱铁矿之间不发生吸附团聚现象.     

柠檬酸在含碳酸盐赤铁矿浮选体系中的分散机理

以赤铁矿、菱铁矿和石英为研究对象,通过沉降试验、Zeta电位测试、傅里叶红外光谱分析和溶液化学计算研究了柠檬酸在强碱性条件下(pH=11.0)的分散机理.沉降试验结果表明,柠檬酸对人工混合矿(赤铁矿-菱铁矿-石英)具有较好的分散效果.动电位和红外光谱测试表明,柠檬酸在赤铁矿和菱铁矿表面的吸附较强烈并使其动电位负移,而在石英表面的吸附较弱并对石英动电位影响较小.溶液化学计算表明,柠檬酸主要以[C_6H_5O_7]~(3-)的形式吸附在赤铁矿和菱铁矿的羟基化表面,进而阻止矿粒间的凝聚.结果表明柠檬酸在含碳酸盐赤铁矿浮选体系中具有分散作用.     

Solution chemistry of carbonate minerals and its effects on the flotation of hematite with sodium oleate

The effects of carbonate minerals (dolomite and siderite) on the flotation of hematite using sodium oleate as a collector were investigated through flotation tests, supplemented by dissolution measurements, solution chemistry calculations, zeta-potential measurements, Fourier transform infrared (FTIR) spectroscopic studies, and X-ray photoelectron spectroscopy (XPS) analyses. The results of flotation tests show that the presence of siderite or dolomite reduced the recovery of hematite and that the inhibiting effects of dolomite were stronger. Dissolution measurements, solution chemistry calculations, and flotation tests confirmed that both the cations (Ca2+ and Mg2+) and CO₃2- ions dissolved from dolomite depressed hematite flotation, whereas only the CO₃2- ions dissolved from siderite were responsible for hematite depression. The zeta-potential, FTIR spectroscopic, and XPS analyses indicated that Ca2+, Mg2+, and CO₃2- (HCO₃-) could adsorb onto the hematite surface, thereby hindering the adsorption of sodium oleate, which was the main reason for the inhibiting effects of carbonate minerals on hematite flotation.     

油酸钠与微细粒黑钨矿的作用机理

通过浮选实验、溶液化学计算、吸附量测试、动电位和红外光谱分析等方法,系统研究了油酸钠对微细粒黑钨矿的浮选捕收机理.结果表明:黑钨矿可浮性与油酸钠吸附量正相关,微细粒黑钨矿可浮性较好的pH区间为7.0～9.0,溶液中油酸离子和离子-分子缔合物组分对黑钨矿浮选过程起主要作用.溶液化学计算表明:油酸钠的吸附量和黑钨矿的可浮性与金属阳离子形成的油酸盐组分浓度有直接关系;油酸钠的添加使荷负电的黑钨矿动电位负移.红外光谱分析表明油酸钠在黑钨矿表面发生化学吸附,生成金属油酸盐,进而增强了黑钨矿的可浮性.     

Improved flotation performance of hematite fines using citric acid as a dispersant

In this study, citric acid was used as a dispersant to improve the flotation performance of hematite fines. The effect and mechanism of citric acid on the reverse flotation of hematite fines were investigated by flotation tests, sedimentation experiments, scanning electron microscopy (SEM), zeta-potential measurements, and X-ray photoelectron spectroscopy (XPS). The results of SEM analysis and flotation tests reveal that a strong heterocoagulation in the form of slime coating or coagulation in hematite fine slurry affects the beneficiation of hematite ores by froth flotation. The addition of a small amount of citric acid (less than 300 g/t) favorably affects the reverse flotation of hematite fines by improving particle dispersion. The results of sedimentation experiments, zeta-potential measurements, and XPS measurements demonstrate that citric acid adsorbs onto hematite and quartz surfaces via hydrogen bonding, thereby reducing the zeta potentials of mineral surfaces, strengthening the electrical double-layer repulsion between mineral particles, and dispersing the pulp particles.     

Effect of sodium alginate on reverse flotation of hematite and its mechanism

Given the gradual increase in the chlorite content of hematite ores, pulp properties seriously deteriorate during flotation. The traditional anion reverse flotation of hematite cannot effectively eliminate the effects of chlorite, leading to a significant decrease in the total Fe (TFe) grade of the concentrate. In this work, the effect of sodium alginate on the reverse flotation of hematite was systematically investigated. Flotation tests of artificially mixed ores were conducted, and the results showed that sodium alginate can significantly improve the removal rates of quartz and chlorite. The adsorption measurements, infrared spectroscopy, and contact angle tests demonstrated that sodium alginate adsorbs on the quartz surface by chelating with calcium ions, thereby weakening the steric hindrance of oleate ions and increasing the adsorption capacity of sodium oleate to ultimately improve the removal rate of quartz. Furthermore, owing to its lower density and fine particle size, chlorite is easily entrained into the foam layer. Sodium alginate dramatically increases the liquid-to-gas ratio of the foam layer by increasing pulp viscosity, thereby increasing the entrainment rate of chlorite and finally improving its removal rate. The core content of this thesis bears significance in improving the Fe grade in the reverse flotation of chlorite-containing hematite.     

柠檬酸对微细粒绿泥石夹带行为的影响

通过浮选试验、Zeta电位测试、红外光谱分析、EDLVO理论计算及扫描电镜(SEM)分析研究了赤铁矿反浮选体系下柠檬酸对细粒绿泥石夹带行为的影响.浮选试验表明:添加柠檬酸促进了细粒绿泥石的夹带行为,有利于脱除铁精矿中的绿泥石.动电位测试和红外光谱分析表明:柠檬酸吸附在绿泥石和赤铁矿表面使其表面负电性增加进而增强其颗粒间的静电排斥力.EDLVO计算结果表明:赤铁矿和绿泥石之间存在吸引力,添加柠檬酸后,其作用力转化为排斥力,该计算同扫描电镜结果一致.     

聚氧化乙烯絮凝微细粒高岭石强化赤铁矿反浮选脱硅机理研究

通过矿物浮选试验并结合激光粒度测试、扫描电镜(SEM)、矿物Zeta电位及XPS等检测方法对赤铁矿反浮选过程中聚氧化乙烯絮凝细粒高岭石的行为及机理进行了研究.矿物絮凝浮选试验表明：添加聚氧化乙烯可以提高高岭石的单矿物回收率和人工混合矿分离效率,促进赤铁矿和高岭石反浮选分离.激光粒度测试和扫描电镜检测结果表明：聚氧化乙烯不絮凝赤铁矿,但絮凝高岭石颗粒,使其表观粒径增大.Zeta电位测试和XPS分析表明：聚氧化乙烯在高岭石颗粒表面发生化学吸附,并使其Zeta电位正移.因此,开展聚氧化乙烯对硅酸盐矿物絮凝的研究对赤铁矿和高岭石反浮选分离具有意义.     

粒度分布对赤铁矿浮选的影响

以赤铁矿为研究对象,通过浮选试验、扩展的DLVO(EDLVO)理论和凝聚动力学研究了粒度分布(粒径小于18μm的微细粒比例)对赤铁矿浮选的影响.浮选结果表明赤铁矿的浮选回收率与粒度的大小和分布有关,粗粒(粒径大于18μm)赤铁矿的粒度较大时或粒度分布均衡时(微细粒与粗粒含量接近)浮选回收率较高.EDLVO理论计算表明微细粒赤铁矿与粗粒赤铁矿之间存在吸引力,且吸引力的大小与粗粒粒度正相关;凝聚动力学分析表明粒度分布均衡时颗粒间的凝聚速率较大.这是粒度分布对赤铁矿的浮选回收率产生影响的主要原因.     

磁种磁团聚强化淀粉对微细粒赤铁矿的抑制

针对赤铁矿反浮选过程中，淀粉对微细粒赤铁矿抑制作用较差的问题，通过浮选试验、EDLVO理论计算、粒度分布和SEM分析，研究了利用磁种磁团聚强化淀粉对微细粒赤铁矿的抑制作用.结果表明，随着赤铁矿的粒度降低，淀粉对赤铁矿的抑制作用变差.添加磁铁矿可强化淀粉对微细粒赤铁矿的抑制作用，随着磁铁矿粒度的增加，强化抑制作用越明显.不同粒级的磁铁矿与微细粒赤铁矿间均存在引力作用，可使磁铁矿与赤铁矿发生磁团聚，且磁铁矿粒度越大，引力作用越强.磁团聚作用增加了微细粒赤铁矿的表观粒度，从而强化了淀粉对微细粒赤铁矿的抑制作用.     

东鞍山浮选尾矿预富集精矿悬浮磁化焙烧试验研究

为实现东鞍山铁矿石浮选尾矿的资源化利用,对浮选尾矿预富集精矿开展了悬浮磁化焙烧试验研究.结果表明,浮选尾矿预富集精矿主要矿物组成为赤褐铁矿、磁铁矿、菱铁矿和石英,TFe品位为31.13%.浮选尾矿预富集精矿适宜的悬浮磁化焙烧工艺参数为:气体流量600mL/min,氢气体积分数20%,焙烧温度520℃,焙烧时间20min.焙烧产品经弱磁选可得铁精矿的TFe品位为64.23%,回收率为79.53%.焙烧产品的铁物相,XRD,VSM分析表明,经过悬浮磁化焙烧后,原矿中赤褐铁矿和碳酸铁转变为磁铁矿,矿石的饱和磁化强度和磁化率增强.     

Flotation mechanisms of molybdenite fines by neutral oils

The flotation mechanisms of molybdenite fines by neutral oils were investigated through microflotation test,turbidity measurements,infrared spectroscopy,and interfacial interaction calculations.The results of the flotation test show that at pH 2-11,the floatability of molybdenite fines in the presence of transformer oil is markedly better than that in the presence of kerosene and diesel oil.The addition of transformer oil,which enhances the floatability of molybdenite fines,promotes the aggregation of molybdenite particles.Fourier transform infrared measurements illustrate that physical interaction dominates the adsorption mechanism of neutral oil on molybdenite.Interfacial interaction calculations indicate that hydrophobic attraction is the crucial force that acts among the oil collector,water,and molybdenite.Strong hydrophobic attraction between the oily collector and water provides the strong dispersion capability of the collector in water.Furthermore, the dispersion capability of the collector,not the interaction strength between the oily collectors and molybdenite,has a highly significant role in the flotation system of molybdenite fines.Our findings provide insights into the mechanism of molybdenite flotation.     

菱铁矿对假象赤铁矿与石英混合矿浮选的影响

碳酸铁对铁矿石的浮选影响极大,严重恶化浮选指标.在三种浮选体系下,研究菱铁矿含量对假象赤铁矿与石英混合矿浮选的影响.结果表明,在十二胺和油酸钠反浮选体系下,菱铁矿加入到两种混合矿中时,浮选指标下降.十二烷基硫酸钠体系下,假象赤铁矿和石英混合矿中加入少量菱铁矿时,精矿品位有所增加.因此,若要实现含碳酸盐铁矿石的有效分选,必须首先消除细粒级菱铁矿的影响.     

变性淀粉在赤铁矿阳离子反浮选脱硅中的抑制性能

以十二胺为捕收剂,木薯原淀粉、取代度为0.026和0.21的羧甲基淀粉和取代度为0.0065和0.055的磷酸酯淀粉作为抑制剂,考察了赤铁矿与石英的可浮性,重点研究了基团取代度对变性淀粉抑制性能的影响.结果表明:原淀粉、取代度0.026的羧甲基淀粉和取代度0.0065的磷酸酯淀粉对赤铁矿有良好的抑制作用,而取代度0.21的羧甲基淀粉和取代度0.055的磷酸酯淀粉对赤铁矿的抑制能力较弱;原淀粉和取代度0.026的羧甲基淀粉对石英有较强抑制作用,其他3种淀粉对石英抑制能力较弱.可见,低取代度的磷酸酯淀粉,在赤铁矿阳离子反浮选脱硅中可作为较高选择性的抑制剂.Zeta电位测定结果表明,特征基团取代度相对较高的变性淀粉,与赤铁矿和石英作用后,矿物Zeta电位负值较大.变性淀粉的取代度越高,其伸展向溶液中荷负电的基团越多,使阳离子捕收剂通过静电作用吸附于矿物表面,减弱了变性淀粉的抑制能力.     

烷基羟丙基胺作用下石英和赤铁矿的浮选行为

通过浮选试验研究了新型捕收剂烷基羟丙基胺(NDIA)作用下石英和赤铁矿的浮选行为,并结合量子化学计算和zeta电位分析,考察了该捕收剂在矿物表面的吸附机理.单矿物浮选试验结果表明:当捕收剂用量为33.33 mg/L,p H值为4.50~8.00时,石英的回收率在92%以上,赤铁矿的回收率在50%左右.人工混合矿分选试验结果表明:当捕收剂用量为33.33 mg/L,淀粉用量为13.33 mg/L,p H值为4.50~8.00时,NDIA均可实现石英和赤铁矿的有效分离.量子化学计算结果表明,与十二胺相比,NDIA对石英具有更好的捕收性能.zeta电位测试结果表明:NDIA在石英和赤铁矿表面均发生了吸附,且在石英表面的吸附作用强于赤铁矿.     

微细矿粒在水溶液中的疏水絮凝

本文着重讨论细微矿物颗粒的疏水絮凝行为及机理。对石英、菱锰矿、赤铁矿及金红石的实验研究表明,矿物润湿性的变化对矿粒悬浮液的分散稳定性有巨大影响。矿粒表面疏水化常与显著的絮凝现象伴生,这种絮凝现象无法用经典的DLVO理论解释。通过对石英-胺及菱锰矿-油酸体系疏水絮凝的理论探讨及势能计算,可以看出表面活性剂吸附而诱发的粒间疏水作用势能远远大干双电层作用或范德华作用势能,因此,疏水作用对此种絮凝行为具有支配地位。     

Influence of the roughness and shape of quartz particles on their flotation kinetics

Surface roughness and shape play an important role on the behavior of particles in various processes such as flotation. In this research, the influence of different grinding methods on the surface roughness and shape characteristics of quartz particles as well as the effect of these parameters on the flotation of the particles was investigated. The surface roughness of the particles was determined by measuring their specific surface area via the gas adsorption method. The shape characteristics of the particles were measured and calculated by images obtained by scanning electron microscopy via an image analysis system. The flotation kinetics was determined using a laboratory flotation cell. The results showed that the particles of rod mill products have higher roughness and elongation ratio and lower roundness than the particles of ball mill products. The flotation kinetics constant of the particles increased with their surface roughness increasing. Particles with higher elongation and lower roundness indicated higher floatability. In addition, the influence of the surface roughness on the flotation kinetics was greater than that of shape parameters.     

改性聚丙烯酰胺对赤铁矿强磁选的影响

基于聚团分选理论,采用改性聚丙烯酰胺(HPM)选择性聚团调浆-湿式强磁选工艺,考察了药剂用量、矿浆pH以及搅拌转速等因素对微细粒赤铁矿强磁分选效果的影响.通过扫描电镜检测、EDS能谱分析、动电位测试以及红外光谱检测等方法研究了物料聚团磁选前后的微观形貌以及药剂作用后矿物表面特性的变化,分析了药剂与矿物表面的作用机理.结果表明:在药剂用量10g/t、矿浆pH 10、搅拌转速954r/min的条件下,采用“选择性聚团-强磁选工艺”与常规强磁选工艺指标相比,精矿铁回收率提高了5.39%.添加HPM调浆后原矿中矿物颗粒表观粒径显著增加,在强磁选作业中添加HPM调浆能够强化对微细粒赤铁矿的回收,HPM对赤铁矿具有选择性絮凝聚团作用,且在赤铁矿表面存在静电吸附和氢键吸附,在石英表面不发生吸附作用.     

用复合絮凝分选法处理东鞍山难选赤铁矿

本文提出一种能有效地选别东鞍山难选赤铁矿石的复合絮凝分选新工艺。实验室小型试验表明,用复合絮凝分选法处理东鞍山多种类型难选赤铁矿石、浮选尾矿以及细粒精矿,均可获得满意的分选指标;对菱铁矿的初步试验也表现出较好的苗头。因此,这种工艺对于解决我国大量微细粒嵌布赤铁矿石的选矿问题具有较大的潜力。