超声波处理对煤泥特性的影响研究

为了提高煤泥浮选的效率和选择性，提出了在浮选前对煤泥进行超声波预处理的方法．利用扫描电镜、激光粒度仪和图像识别软件等研究了超声处理对煤泥特性的影响．比较了超声波处理前后相同粒级煤泥的产率、硫分、灰分和圆形系数，分析了超声波处理前后煤泥颗粒的表面状态，并用真空浮选试验进行了验证．浮选速度试验结果表明，超声处理后精煤的硫分、灰分较超声波处理前分别降低了33．84％和32．09％，前2min的精煤产率平均提高了约10％．试验证明超声处理改变了煤泥颗粒的大小、形状以及煤粒表面的状态，促使煤粒与黄铁矿、矸石解离，因此超声波预处理是煤泥浮选脱硫降灰的一种有效方法．     

Research on Effect of Magnetized Pulp on Coal Slime Flotation

Effect of magnetization on oxygen concentration, pH, surface zeta potential, and wet heat of flotation pulp were researched. The result shows that magnetization treatment can improve the floatablility of coal and increase the difference in wet heat among coal, refuse, and pyrite, which is favorable for slime flotation and for removing sulfur and ash from coal.     

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。     

Coal flotation using wash oil as a new type of collector

The use of wash oil as a coal collector is proposed to overcome the disadvantages of regular collectors in coal slime flotation. These disadvantages include high price, limited sources and high consumption. The effect of additives on flotation was studied and an innovative "one rough separation-one cleaning separation" flotation technology was developed. The experimental results show that the clean coal ash content decreases by about 1.36% and the clean coal yield declines by around 10% with the application of the depressant. There is an increase of 3.76% in the yield of clean coal and a decrease of 0.40% in the ash content caused by utilizing a dispersant. An ultimate product having an ash content of 10.78% and yield of 70.12% can be attained using a combination of dispersant and depressant. The use of this new technology decreases the ash content by 1.21%, decreases the yield by 2.80% and an increases the coal flotation perfect index by 2.03%. Compared to common flotation, the utilization of the new technology reduces ash by 0.17%, increases yield by 5.3% and increases perfect index by 4.18%.     

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     

An Entrapment Model of Water Flow on Fine Coal Flotation

Effect of entrapment of water flow on fine coal flotation was studied. The relation between constant of water flotation rate and flotation time was investigated and the water recycling model determined. The entrapment model of water flow about the relation between the recovery of fine particle and that of water in concentration was established. Finally, the equation about ash in fine clean coal at any time was derived by introducing a de-ashing coefficient.     

药剂磁化处理对煤泥浮选效果影响的研究

研究了磁化处理对浮选药剂性能和浮选效果的影响．结果表明：经磁化处理后轻柴油的表面张力和黏度分别降低了7．91％和13．669／5，仲辛醇的表面张力和黏度分别降低了3．739／5和7．87％，磁化处理后轻柴油在煤表面吸附量增加幅度约为在煤矸石和黄铁矿表面吸附量增加幅度的1倍．磁化处理捕收剂、起泡剂对煤和煤矸石的可浮性均有影响，对煤的影响尤为显．磁化处理后水玻璃对煤矸石、黄铁矿的抑制效果增强，而对煤无明显影响．     

Desulfurization of coal by an electrochemical-reduction flotation technique

The optimum conditions for sulfur removal from coal by electrochemical reduction flotation in an aqueous NaCI solution were determined from orthogonal experiments. The effect of electrolytic conditions on the desulfurization ratio was also studied.The electrochemical-reduction processed coal was examined by X-ray diffraction, Fourier transform infrared spectroscopy and wet chemical analysis. The results show that electrochemical reduction converts hydrophobic pyrite in Nantong coal into hydrophilic FeS and S2 and leads to an increase in the concentration of hydroxyl groups and aliphatic moieties and a corresponding decrease in carboxyl and carbonyl groups, which enhances the flotation desulfurization of the coal.     

不同煤阶煤表面改性的FTIR谱研究

用傅立叶变换红外光谱（FTIR）方法对煤样进行了测试,研究了煤表面改性前后官能团含量的变化。结果表明,随着煤的变质程度增高,含氧官能团减少。当采用不同的电化学法还原处理后,不同变质程度煤的含氧官能团也都有不同程度的减少。含氧官能团的减少能使煤的疏水性增强,同时黄铁矿表面的亲水性增强,有利于浮选脱硫的进行。     

煤泥高效调浆理论研究与应用

基于煤粒与捕收剂充分接触和有效黏附是实现煤泥调浆前提条件的认识,应用Sommer-feld颗粒间碰撞模型,导出了调浆过程中颗粒分散后的碰撞概率,并用颗粒绕流效应对碰撞概率进行了修正,考察了高剪切条件下实际流场中油滴与煤泥颗粒碰撞的规律.提出了捕收剂与煤泥颗粒有效吸附概率的概念,讨论了煤泥高效调浆的技术途径,并进行了调浆试验.结果表明:提高调浆剪切强度,保证调浆时间是确保浮选精煤回收率和质量的关键,过度调浆不利于提高浮选精煤回收率.     

Effect of chemical conditioning on the triboelectrification of coal and mineral particles

Chemical conditioning was used to modify the triboelectrification of coal and mineral particles.The chemicals tested included starch,lignin,kerosene,ethanol,acetic acid,salicylic acid,sodium oleate,Sodium Hexametaphosphate(SH),sodium silicate,Sodium Dodecylbenzenesulfonate(SDBS),Sodium Bicarbonate(SB)and ammonia.A high-speed,dry mixing method was employed.The charge-to-mass ratio of the coal and mineral samples,both untreated and treated,was tested using a Faraday cup.Dielectric constants were determined by measuring capacitance.It is found that the selectivity of the additives toward coal or minerals is not consistent.Salicylic acid is the optimal additive to enhance the triboelectrification performance of coal samples.Starch,lignin and sodium oleate arc suitable for removal of pyrite.SH,sodium silicate,SDBS,SB and ammonia are suitable additives for the removal of ash-forming minerals.     

Nanobubble generation and its applications in froth flotation(part Ⅳ): mechanical cells and specially designed column flotation of coal

Coal is the world's most abundant fossil fuel.Coal froth flotation is a widely used cleaning process to separate coal from mineral impurities.Flotation of coarse coal particles,ultrafine coal particles and oxidized coal particles is well known to be difficult and complex.In this paper,the nanobubbles' effects on the flotation of the varying particle size,particle density and floatability coal samples were evaluated using a bank of pilot scale flotation cells,a laboratory scale and a pilot scale specially designed flotation column.The parameters evaluated during this study include the flow rate ratio between the nanobubble generator and the conventional size bubble generator,the superficial air velocity,collector dosage,frother concentration,flotation feed rate,feed solids concentration,feed particle size,and the superficial wash water flow rate,etc.The results show that the use of nanobubbles in a bank of mechanical cells flotation and column flotation increased the flotation recovery by 8%～27% at a given product grade.Nanobubbles increased the flotation rate constants of 600～355,355～180,180～75,and 75～0 microns size coal particles by 98.0%,98.4%,50.0% and 41.6%,respectively.The separation selectivity index was increased by up to 34%,depending on the flotation feed characteristics and the flotation conditions.     

Effect of organic depressant lignosulfonate calcium on separation of chalcopyrite from pyrite

In order to selectively separate chalcopyrite from pyrite, the effect of organic depressant lignosulfonate calcium (LSC) on the flotation separation of chalcopyrite from pyrite was investigated by flotation tests. The depression mechanism was studied by Fourier-transform-infrared (FTIR) analysis. The flotation tests of single mineral show that LSC can depress the flotation of pyrite in a certain pH range, but it has little effect on chalcopyrite flotation. Flotation separation of a mixture of chalcopyrite and pyrite can be completed to obtain a copper concentrate grade up to 24.73% with a recovery of 80.36%. IR analysis shows that LSC and butyl xanthate compete in absorption on pyrite surface, and there exists an LSC characteristic peak on pyrite surface. There is little adsorption of LSC on chalcopyrite.     

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.     

Effect of radiation on wettability and floatability of sulfide minerals

The feasibility for modifying the wettability and floatability of sulfide minerals by electron beam irradiation has been studied experimentally. The wettability of crystalline pyrite and floatability of some sulfide as pyrite, arsenopyrite, chalcopyrite and marmatite after irradiation were examined by flotation in a modified Hallimond tube. Experimental results show that the hydrophobicity of crystal-line pyrite enhances with the increase of irradiation dose in a low dose range. And the flotation responses of sulfide minerals on irradiation dose vary with the mineral species and particle size. The floatability of minerals can be regulated by altering irradiation dose. An explanation for the mechanism has been suggested based on the principle of radiation chemistry.     

营养条件对氧化亚铁硫杆菌生长和脱硫的影响

考察了氧化亚铁硫杆菌（T.f.）对不同氮源、能源的利用,研究了空气中氧化不同时间的煤系黄铁矿的脱硫情况.结果表明：在选择的3种氮源中,尿素经过诱导可被T.f.菌较好地利用,提示该菌可产生诱导性脲酶.在利用尿素初期由于尿素的水解,提高了溶液中的pH值.在选择的能源中,Fe^2＋是T.f.菌容易利用的能源基质.添加培养过的回收单质硫粉可提高菌体生物氧化速率.空气中氧化20 d的煤系黄铁矿有助于菌体的吸附,但吸附菌体的生物氧化速率较低.脱硫过程中30 d后对于空气中氧化4 d的煤系黄铁矿,同时接种亚铁与单质硫培养的菌种其黄铁矿硫脱除率达52.2%,接种亚铁培养的菌种其黄铁矿硫脱除率为43.2%,接种单质硫培养的菌种其黄铁矿硫脱除率为33.9%.     

Process mineralogy of copper-nickel sulphide flotation by cyclonic-static micro-bubble flotation column

In our study we investigated a refractory copper-nickel sulfide ore separation by using a cyclonic-static micro-bubble flotation column (FCSMC). The process mineralogy of the main products was studied. Using a scanning electron micro-scope-energy dispersive system (SEM-EDS) and an X-ray spectrometer the mineral category and content of samples were analyzed. By using a mineral liberation analyzer (MLA) the mineral liberation characteristics were revealed. It is shown that in roughing feed the monomers liberation degree of nickel pyrite and chalcopyrite take up 84.11% and 88.82%, respectively. In tailings, the lost nickel pyrite and chalcopyrite are mainly monomers. Therefore, strengthening the micro-fine particle recovery capacity is the key to increase recovery.     

脂类捕收剂DLZ对黄铜矿和黄铁矿浮选的选择性作用

通过浮选实验、吸附量和红外光谱测定,考察了捕收剂DLZ对黄铜矿和黄铁矿浮选性能的影响及作用机理.结果表明:DLZ在pH=2.7～12.05时对黄铜矿的捕收能力强,最大回收率95.7%,而对黄铁矿的捕收能力弱,且PH=6.9～12.05时其回收率小于10%.用CaO作pH调整剂时,在pH=7～11时黄铜矿的回收率与用NaOH调PH相差不大,但黄铁矿可浮性被抑制,回收率低于5%.DLZ在黄铜矿上的吸附量比在黄铁矿上的大,特别是强碱条件下;其吸附量随用量的增加而增大.DLZ与矿物作用的红外光谱分析表明:黄铜矿与DLZ作用后出现了DLZ的相关特征吸收峰,而黄铁矿与DLZ以及Cu~(2+)作用前后的红外光谱曲线基本没有变化,可见DLZ在黄铜矿表面的吸附属于化学吸附,在黄铁矿表面的吸附属于物理吸附.     

Research on Factors Affecting Flotation and Desulfurization of Coal by Electrochemical Method

Influence of factors such as potential of electrolyte, electrolyzing time, concentration of electrolyte, and pH value on flotation and desulfurization of coal was researched. The result shows that the electrochemical reduction can enhance the desulfurization effect and increase the yield of clean coal under certain conditions. So it is an effective method.     

Effects of clay and calcium ions on coal flotation

The microflotation of three single minerals, mixed coal–kaolinite and mixed coal–montmorillonite were examined to study the effects of clay and calcium ions on coal flotation. The results show that the ash content of flotation concentrate increases by 3% in the presence of clay minerals, and the ash content would further increase by 3% in co-presence of clay minerals and high concentration of Ca²⁺. Scanning electron microscope (SEM) images and elemental spectrum analysis indicate that fine clay particles that coat on the coal surface, which is called slime coating, can affect the coal flotation. The slime coating would be induced much more easily in the presence of Ca²⁺.