脆硫锑铅矿在乙硫氮饱和Ca(OH)_2体系中的电化学

采用循环伏安和交流阻抗法研究了脆硫锑铅矿在乙硫氮饱和Ca(OH)2体系中的电化学,讨论了电位调控浮选脆硫锑铅矿的工艺参数。电位在-378～22mV范围内,矿物的界面电容不断减少,介电常数变小,表面产物是疏水性的(CH3)2NCSS-、Pb((CH3)2NCSS-)2和S0;电位在22～222mV范围内时,矿物表面的疏水产物膜迅速破裂,电容增加,介电常数变大,界面亲水性增强。随着电位的继续升高,矿物表面不断产生亲水性离子和Fe(OH)3的沉积;对于乙硫氮饱和Ca(OH)2水溶液体系,脆硫锑铅矿的电位调节浮选的工艺参数应控制在-178～122mV之间,实际工艺中电位控制在-78mV～50mV范围为宜。     

Bioleaching of sphalerite by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans cultured in 9K medium modified with pyrrhotite

Elective culture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans in 9K medium modified with pyrrhotite was studied. Bioleaching of flotation concentrate of sphalerite by the selected bacteria was carried out. The results show that the microorganisms cultured by pyrrhotite are a mixture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans, of which the capability to oxidize ferrous to ferric irons is enhanced by the high mass ratio of Fe to S in pyrrhotite. Three pyrrhotite samples were separated into various parts with corresponding S/Fe ratios by magnetic separation and were used to culture the elective bacteria as the substrate. The association of the cultures could provide a more rapid and complete oxidation of sphalerite than that of bacteria cultivated by conventional methods.     

硫化铜矿诱导浮选及其机理的研究

本文详细地考察了黄铁矿的诱导浮选行为。研究表明，黄铜矿具有良好的自诱导可浮性；黄铁矿的自诱导可浮性很关，但在合适的硫化钠用量条件下，具有良好的硫诱导可浮性。与捕收剂诱导浮选相比，自诱导使铜硫分选的ＰＨ区域增宽。以此为依据可提出了铜硫浮选分离分离的新方案设计。     

Density functional study for structure and electronic properties of FeS_2(100)

1　INTRODUCTIONThereactivityoftheFeS2 (pyrite)surfaceisofparticularimportantintheengineeringapplications ,includingsulfidemineralsflotation[1] ,bioleachingoflow gradechalcopyrite containingore[2 ] ,coal pro cessing ,hydrometallurgy ,environmentalengineer ing ,geochemistry ,andphotovoltaiccell,etc[3] .Es pecially ,anunderstandingofhow pyritesurfacesin teractwithflotationreagentmoleculeswillaidinthedesignofmoreeffectiveflotationsuppressants ,whichwouldeffectivelyseparatethedesirableoresfrom…     

Calculation of electron structure by density function theory and electrochemical process of surface （100） of FeS2

The electron structure of FeS2 surface (100) was computed by DFT (density function theory) and the process of electron transfer in sulfide flotation was simulated through ab-initio calculation. The results show that the interaction between xanthate and FeS2 is controlled by the energy of valence band. The products and degree of the reaction depend on the density of state of valence band and concentration of positive hole in valence band. Interaction between xanthate and pyrite can be changed by modifying the election structure of the surface of pyrite. Xanthate is adsorbed on the surface of intrinsic pyrite. But the amount of xanthate adsorbed on the surface of the pyrite with sulfur vacancy is more than that on the surface of the intrinsic pyrite due to the higher electron and vacancy density. Xanthate is not adsorbed on the surface of pyrite with Fe vacancy because of its high Fermi energy.     

Oxygen adsorption on pyrite （100） surface by density functional theory

Pyrite (FeS2) bulk and (100) surface properties and the oxygen adsorption on the surface were studiedby using density functional theory methods. The results show that in the formation of FeS2 (100) surface, there exists a process of electron transfer from Fe dangling bond to S dangling bond. In this situation, surface Fe and S atoms have more ionic properties. Both Fe^2 and S^2- have high electrochemistry reduction activity, which is the base for oxygen adsorption. From the viewpoint of adsorption energy, the parallel form oxygen adsorption is in preference The result also shows that the state of oxygen absorbed on FeS2 surface acts as peroxides rather than O2.     

Recovery of zinc from low-grade zinc oxide ores by solvent extraction

1　INTRODUCTIONZincoxideoresarethemainsourceofzincmetalaf terzincsulfideores .Withtheescalatingdepletionofzincsulfideores,zincoxideoresincludingwillemite(Zn2 SiO4 ) ,hemimorphite[Zn4 (Si2 O7) (OH)·H2 O]andsmithsonite (ZnCO3) ,becameanimportantsourceofzinc[1] .InChina,zincoxideoresarerelativelyabundant,whicharemainlystoredinsouthwestandnorth westChi na,suchasYunnan ,Sichuan ,GuangxiandGansuprovince[2 ] .Manystudieshavebeendoneontheconcentrationofzincoxideores,yettheprogressesaresli…     

阳离子表面活性剂在一水硬铝石表面吸附研究

采用荧光探针法研究了在烷基伯胺和季铵盐阳离子表面活性剂在一水硬铝石表面吸附层结构，研究结果表明，低浓度且阳离子表面活性剂在一水硬铝石表面为静电吸附时，其表面微极性大，阳离子表面活性剂零星吸附于矿物表面，当阳离子表面活性剂浓度增加时，一水硬铝石表面的微极性降低，阳离子表面活性剂在一水硬铝石表面形成了胶束吸附，形成胶束的表面活性剂离子的数随其浓度的增加而增加，表面疏水性逐渐增强，直至完全疏水，随着烃链碳原子数的增加，阳离子表面活性剂在一水硬铝石表面形成胶束吸附的浓度降低，烷基伯胺为弱电解质，其在水溶液中同时存在烷基胺离子和分子，由于离子分子共同吸附，烷基伯胺比相同碳原子数的季铵盐在一水硬铝石表面形成的半胶束吸附的分子数多。     

表面改性对JT-235浮选铜钼矿的影响

难选铜钼矿难于浮选的原因主要是矿物表面被氧化。通过对铜钼矿表面改性,然后采用新型浮选剂JT-235进行浮选,研究结果表明,经过电场改性后,铜钼矿石铜回收率达到79%,钼回收率增加到75%；经过碱改性后,铜回收率增加到89%,钼回收率增加到84%；经过盐酸改性后,铜回收率最高达到83．5%,钼回收率达到80%。改性方法简单可行,成本增加不大。     

金粉的电化学调控浮选实验室研究

用改进的挂槽式研究了纯金粉在不同条件下的可浮性，重点考查了电位对金粉可浮性的影响，得到了最佳的浮选条件：电位ψ＝０－０．４Ｖ（ＳＨＥ），ＰＨ＝９．０和「Ｎａ２Ｓ」＝１０＾－４－－１０＾－５ｍｏｌ／Ｌ。实验结果表明，纯金粉也具有较好的硫诱导电化学调控可浮性。