方铅矿与黄铁矿浮选分离的矿浆电化学研究：Ⅲ.方铅矿与黄铁…

以丁基黄捕收剂的方铅矿与黄铁矿混合精矿体系，按照电位与可浮性的关系，两矿物在还原性矿浆电位浮选分离的电位差在热力学上仅为５０ｍＶ，而在动力学上达到了２０７ｍＶ。采用接触角测定、单矿物浮选、混合矿分离等方法，可以证实依据方铅矿表面丁基黄原酸铅和黄铁矿表面丁基双黄药的电化学还原动力学性质的差异，实现方铅矿与黄铁矿混合精矿的电化学浮选分离。     

磁化浮选工艺脱硫降灰的研究

针对细粒煤脱硫难的问题,采用磁化浮选工艺对高硫煤进行脱硫降灰的研究,利用煤与黄铁矿的磁性及可浮性的差异进行分离。实验证明,该方法具有一定的优越性,与常规浮选法相比脱硫率提高７％。     

黄铁矿浮选中抑制剂WHL-Y1降镁的作用机理

在黄铁矿浮选中,使用抑制剂WHL-Y1可有效地降低精矿中MgO含量.通过工艺矿相研究及吸附量、Zata电位、红外光谱测定,研究了WHL-Y1的作用机理:WHL-Y1中的-P-OH离子可以与矿物表面的Mg2+(Ca2+)发生化学反应,增强不纯黄铁矿的亲水性,在浮选时使其受到抑制,较纯黄铁矿可以优先浮选分离.     

黄铁矿浮选中抑制剂WHL-Y1降镁的作用机理

在黄铁矿浮选中,使用抑制剂WHL-Y1可有效地降低精矿中MgO含量.通过工艺矿相研究及吸附量、Zata电位、红外光谱测定,研究了WHL-Y1的作用机理：WHL-Y1中的-P-OH离子可以与矿物表面的Mg^2＋（Ca^2＋）发生化学反应,增强不纯黄铁矿的亲水性,在浮选时使其受到抑制,较纯黄铁矿可以优先浮选分离.     

金属腐蚀电偶法强化煤浮选脱硫的研究

为拓宽电化学法在煤脱硫中的应用及提高煤的可浮性，研究了金属腐蚀电偶法的各因素对脱硫效果的影响和对高硫煤的浮选脱硫机理．利用红外光谱和X射线衍射对金属腐蚀电偶法处理前后的煤样进行了分析．结果表明：各因素的影响次序从大到小为反应时间、反应温度、金属用量、pH．确定了最佳反应条件，反应时间为30min，反应温度为40℃，金属用量为理论用量的2倍，pH为5，脱硫率可达到61．39％；而且还能脱出部分有机硫．金属腐蚀电偶法脱硫是一种高效、安全、温和的脱硫方法，它能使煤与黄铁矿颗粒表面朝不同的方向改性，提高煤的可浮性，降低黄铁矿的可浮性．     

药剂与超声波处理的选煤方法研究

采用浮选药剂和超声波技术相结合的方法进行了煤的浮选试验 ,结果表明 :BET作为煤的浮选药剂 ,比 GF,FS2 0 2两种常用药剂用量少 ,分别是它们的 1 /1 0和 1 /1 0 0 ;此外 ,BET选择性强 ,对煤系黄铁矿捕收性差 ,浮选黄铁矿时用 BET的上浮物是用 GF,FS2 0 2时的 1 /1 0～1 /2 0 .超声波的强化作用进一步提高了抑制剂的作用效果 ,使脱硫降灰的指标有了明显的提高(达 1 5 %以上 ) ,如介休煤样的黄铁矿脱硫率在 85 %左右 ,脱硫完善度达到 6 8.97% .抑制剂 Ca O和水玻璃同时使用可以提高脱硫降灰效果 ,比二者单独使用效果好     

高硫煤电化学调浆浮选脱硫XRD谱研究

对山东兖州,内蒙乌达高硫煤进行了电化学调浆处理,运用X－射线衍射（XRD）测试技术从定性,定量两个方面对高硫煤电化学调浆浮选脱硫进行了研究,实证了煤中黄铁矿被氧化作为多硫化铁的事实。结果表明,电化学调浆不破坏煤的结构,经过电化学调浆浮选,能有效的脱除煤中硫,尤其是黄铁矿硫,它是一种温和,无污染,高效的脱硫新方法。     

黑石山铜矿石浮选中抑制剂的研究

在浮选黑石山铜矿石中，使用CaO-YN-2代替CaO作抑制剂，不仅能有效抑制黄铁矿，得到优质铜精矿，而且使精矿中银的品位和回收率都得到上升．明显提高了矿产资源利用率．     

黑石山铜矿石浮选中抑制剂的研究

在浮选黑石山铜矿石中,使用CaO-YN-2代替CaO作抑制剂,不仅能有效抑制黄铁矿,得到优质铜精矿,而且使精矿中银的品位和回收率都得到上升.明显提高了矿产资源利用率.     

红假单胞菌在煤系黄铁矿表面吸附量的测定

微生物在黄铁矿表面吸附量的大小，直接影响微生物对黄铁矿的表面改性，决定浮选脱硫效果的优劣．利用红假单胞菌，通过测定吸附前后菌液浓度的变化，对煤系黄铁矿进行吸附量测定试验，重点考察了菌种的浓度、矿浆浓度、pH值等因素对吸附量的影响．研究结果表明，红假单胞菌在黄铁矿表面的吸附量遵守Langmuir等温方程式，吸附量与矿浆浓度成反比，pH值对红假单胞菌吸附量有影响，在中性环境下吸附量最高，在碱性环境下吸附量较小，在酸性环境下吸附量最低．红假单胞菌与黄铁矿的吸附作用中，存在静电引力．     

Influencing factors of pyrite leaching in germ-free system

The effect of mineral particle size, pulp potential and category of oxidant on pyrite leaching was studied. The results show that a smaller mineral particle size leads to a higher leaching rate of pyrite, and the optimum result with pyrite leaching rate of 2.92% is obtained when mineral particle size is less than 0.037 mm. The pulp potential reflects the leaching process. The increase of pulp potential can improve pyrite leaching. The leaching rate and velocity of pyrite can be enhanced rapidly by adding strong oxidant. The kind and the method of adding oxidant have important effect on the pyrite leaching. Appropriate concentration of Fe3 can enhance pyrite leaching but the precipitation generated by high concentration of ferric ion covers the surface of pyrites and prevents the leaching process. The leaching rate increases with the constant addition of H2O2.     

Influences of collector DLZ on chalcopyrite and pyrite flotation

The interaction mechanism of collector DLZ in the flotation process of chalcopyrite and pyrite was investigated through flotation experiments, zeta potential measurements and infrared spectrum analysis. Flotation test results indicate that DLZ is the selective collector of chalcopyrite. Especially, the recovery of chalcopyrite is higher than 90% in neutral and weak alkaline systems, while the recovery of pyrite is less than 10%. When using CaO as pH regulator, at pH=7-11, the floatability of pyrite is depressed and the recovery is less than 5%. Zeta potential analysis shows that the zeta potential of chalcopyrite decreases more obviously than that of pyrite after interaction with DLZ, confirming that collector DLZ shows selectivity to chalcopyrite and pyrite. And FT1R results reveal that the flotation selectivity of collector DLZ is due to chemical absorption onto chalcopyrite surface and only physical absorption onto pyrite surface.     

Depressing effect of hydroxamic polyacrylamide on pyrite

The performance of hydroxamic polyacrylamide(HPAM) in mineral flotation was tested on the samples of calcite, diaspore and pyrite. It is found that HPAM expresses intensive depression on pyrite and can be used as effective depressants for pyrite. The depression mechanism of HPAM to pyrite was investigated by the determination of contact angle, zeta potential, adsorptive capacity for collectors and infrared spectrum. A lower contact angle,more negative zeta potential, less xanthate adsorptive capacity, and the formation of chemical bonding were determined, which reveals that the strong chemical interactions exist between HPAM and pyrite surface. The group electronegativity of HPAM was calculated to explain the differences of interaction between reagent and minerals.     

黄铁矿伴生金回收研究进展

Pyrite is one of the most important minerals bearing gold, and also the major resource of the gold production in China. However, the gold associated with pyrite is reported to be finely disseminated in complex structure, resulting in great recovering difficulty. This article reviews the mineralogical characteristics of gold associated with pyrite, and the research progress of common physical and chemical beneficiation processes for it. The principle of each gold extraction method and its applications in the recovery of gold associated with pyrite were illuminated, the merits and demerits of each method were discussed as well from the aspects of process cost, environmental hazard and gold leaching efficiency, etc. It is pointed out that, for refractory gold associated with pyrite, developing effective pretreatment process and highly selective leaching aids will be the future research directions to improve the gold leaching efficiency.
     

Bioflotation of pyrite with Thiobacillus ferrooxidans

Bioflotation of pyrite with bacteria Thiobacillus ferrooxidans in the presence or absence of potassium ethyl xanthate was studied on a pure pyrite through microflotation and electrophoretic light scattering measurements. The experimental results showed that in the absence of xanthate, pyrite flotation is slightly enhanced by Thiobacillusferrooxidans. However, with xanthate as a collector, pyrite flotation is strongly depressed after being exposed to the bacteria. The longer is the time when the pyrite is exposed to the bacteria, the stronger the depression is. The mechanism of the depression might be due to the formation of the biofilms of Thiobacillus ferrooxidans on pyrite surfaces, preventing the adsorption of xanthate on pyrite surfaces in the form of dixanthogen or xanthate ions.     

微粉煤的电性质及摩擦带电研究

为了提高煤的摩擦电选脱硫降灰效率,应用同心圆筒测量法研究了煤及伴生矿物颗粒的比电阻、应用开尔文探针法研究了煤及伴生矿物与不锈钢的接触电位差、应用法拉第桶测量了煤及伴生矿物的摩擦带电荷质比.结果表明：净煤和高岭石与不锈钢间的接触电位差为正值,在与不锈钢摩擦时带正电,而黄铁矿和石英与不锈钢间的接触电位差为负值,在与不锈钢摩擦时带负电;小于1.6 g/cm^3各密度级和大于1.6 g/cm^3各密度级摩擦带电符号相反.温度升高或湿度降低使得颗粒的电阻率升高,有利于提高颗粒的摩擦带电量和分选效率.     

电解还原法强化高硫煤浮选脱硫机理研究

采用电解还原法对高硫煤预处理后，使煤表面的含氧官能团减少，疏水性增强；同时，黄铁矿表面初始氧化产物如单质硫和多硫化物被还原，亲水性增强．煤粒和黄铁矿颗粒两者的表面性质向相反的方向改性，从而实现强化浮选分离的目的，理论上分析了煤和黄铁矿表面的改性机理，并通过试验验证了电解还原法强化浮选能够明显地降低浮选精煤中的硫分．对不同煤样的浮选结果表明：北宿煤样的黄铁矿脱除率可达89％以上。     

Bio-leaching effects of Leptospirillum ferriphilum on the surface chemical properties of pyrite

Leptospirillum ferriphilum cultured using different energy sources (either soluble ferrous ion or pyrite) changed the surface properties of pyrite.Cell adsorption,zeta-potential,hydrophobicty,FT-IR spectra and surface morphology were investigated.Adhesion of bacterial cells to the pyrite surface is a fast process.Furthermore,the adsorption of cells grown in pyrite is greater than of cells grown in soluble ferrous ion.The Iso-Electric Point (IEP) of pyrite treated with L.ferriphilum approaches that of the cells thcmselves.The contact angle of the pyrite surface was observed to decrease due to the surface formation of some hydrophilic substances during bio-leaching.Changes in pyrite surface properties after bacterial treatment support the idea that ferric ion plays an important role and that indirect bio-oxidation is the principal mechanism of pyrite bio-leaching.     

THE DEPRESSION OF PYRITE FLOTATION BY THIOBACILLUS FERROOXIDANS

The experimental studies on the microbial flotation of a pure pyrite sample using Thiobacillus ferrooxidans was conducted in the laboratory.The results indicate that Thiobacillus ferrooxidans has strong depression effect on the flotation of pyrite.Thiobacillus ferrooxidans can adsorb on the surface of pyrite in a very short time (a few min.),changing the surface from hydrophobic into hydrophilic and making the pyrite particles to lose their floatability.Therefore, Thiobacillus ferrooxidans is an effective microbial depressant of pyrite.It has also been pointed out that the depression of pyrite by Thiobacillus ferrooxidans is caused by the adsorption of the microbial colloids, but not by the oxidation effect.     

旋流板塔煤浆法烟气脱硫研究

煤浆法烟气脱硫是以煤浆洗涤含二氧化硫的烟气,二氧化硫溶于浆液形成亚硫酸,煤中黄铁矿与亚硫酸、氧气发生反应,亚硫酸被氧化为硫酸,从而实现烟气脱硫.反应过程中,煤中的黄铁矿硫也被转化为硫酸而浸出,反应产生的Fe3＋/Fe2＋又对脱硫反应起到了催化剂的作用.以旋流板塔为吸收设备,研究了煤浆法烟气脱硫过程中浆液温度、液气比、空塔气速及浆液固液比等操作参数对脱硫率的影响规律.试验表明,在其他条件不变的情况下,适当提高液气比、空塔气速及浆液固液比均有利于提高脱硫效果.随着烟气脱硫过程的进行,脱硫浆液中的总铁含量不断增加,说明煤中黄铁矿被不断浸出,故此法在脱除烟气中的二氧化硫的同时也降低了煤中黄铁矿硫含量.