Kinetics of electrochemical process of galena electrode in diethyldithiocarbamate solution

1　ＩＮＴＲＯＤＵＣＴＩＯＮＤｉｅｔｈｙｌｄｉｔｈｉｏｃａｒｂａｍａｔｅ (ＤＤＴＣ)ｉｓｏｎｅｏｆｔｈｅｍｏｓｔｆｒｅｑｕｅｎｔｌｙｕｓｅｄｃｏｌｌｅｃｔｏｒｓｆｏｒｆｌｏｔａｔｉｏｎｏｆｈｅａｖｙ ｍｅｔａｌｓｕｌｆｉｄｅｍｉｎｅｒａｌｓ ,ｓｕｃｈａｓｇａｌｅｎａ ,ｃｈａｌｃｏｐｙｒｉｔｅａｎｄｊａｍｅｓｏｎｉｔｅ ,ａｎｄｉｔｓｈｏｗｓｓｔｒｏｎｇｓｅｌｅｃｔｉｖｉｔｙ[1] .ＷｈｅｎＤＤＴＣｗａｓｕｓｅｄｉｎｈｉｇｈｌｙａｌｋａｌｉｎｅ (ｐＨ >11.4 )ｆｏｒｓｅｐａｒａｔｉｎｇｇａｌｅｎａｆｒｏｍｓ…     

某含易浮脉石型复杂铅锌矿浮选试验研究

某铅锌矿原矿Pb品位6.67%,Zn品位13.26%,矿石中含有一定量的易浮脉石——碳质物,同时含硫较高,原矿S品位32.51%,属复杂难选铅锌矿石。矿石中方铅矿嵌布粒度不均匀,且与闪锌矿、黄铁矿共生关系复杂,严重影响选矿过程中铅锌分离及铅硫分离。根据原矿性质,采用“易浮脉石预先浮选-铅锌依次优先”浮选工艺流程进行试验研究,实验室闭路试验获得铅精矿铅品位53.22%,铅回收率85.07%,含锌8.73%;锌精矿锌品位56.19%,锌回收率83.68%,含铅1.23%,实现了铅、锌矿物和黄铁矿的高效分离。     

川滇黔接壤地区铅锌矿床成矿物质来源:方铅矿原位Pb同位素制约

位于扬子板块西南缘的川滇黔铅锌矿集区,是我国以碳酸盐岩为容矿岩石的铅锌矿产最为集中发育的区域,在我国铅锌成矿区/带中占有重要地位。尽管以往研究取得了丰硕的理论认识和找矿成果,但是对研究区铅锌矿床的成矿物质来源一直存有争议。以9个赋存于震旦系(乌斯河、赤普、银厂沟和茂租矿床)、泥盆系(火德红、毛坪和猫榨厂矿床)和石炭系(毛坪、会泽、亮岩和猫榨厂矿床)中的铅锌矿床为例,进行了较为系统的方铅矿原位Pb同位素地球化学综合研究。结果表明:①乌斯河、赤普、银厂沟、茂租、火德红、毛坪、猫榨厂、会泽、亮岩矿床原位Pb同位素组成的线性关系明显,其Pb-Pb等时线年龄约为2.5 Ga((2 574±30)Ma),暗示这些矿床的成矿物质来源相同,且太古代—古元古代结晶基底岩石是最可能的主要金属源区; ②在赋矿地层时代上,Pb同位素组成由老(震旦系)至新(石炭系)逐渐增加; 在赋矿层位空间上,Pb同位素组成由北(西)部的乌斯河、赤普矿床向南(东)部的猫榨厂、亮岩矿床逐渐增加; 这些特征暗示其是同一成矿流体不同演化阶段的产物,且在区域尺度上来源或流经结晶基底岩石的成矿流体由深部向浅部、由北(西)向南(东)方向运移演化。     

方铅矿新型抑制剂BK508C及其作用机理研究

针对钼铅分离过程使用磷诺克斯抑铅浮钼存在毒性大、污染严重等问题,开展了新型环保型抑制剂BK508C替代磷诺克斯试验研究。采用单矿物浮选试验和人工混矿浮选试验的方法研究了BK508C对辉钼矿与方铅矿浮选行为的影响,并通过分子模拟、接触角测试、吸附量测定和红外光谱分析等方法研究其作用机理。单矿物浮选试验采用12.5mg/L用量的BK508C可使方铅矿的回收率降至10.82%,人工混矿分离试验分离系数达到6.32,分离效果高于磷诺克斯,说明BK508C可以替代磷诺克斯试剂实现钼铅分离。机理研究表明,BK508C与Pb_²⁺以1:1配位方式形成络合物,化学吸附在方铅矿表面,在辉钼矿表面吸附较弱,可以实现选择性抑铅浮钼。     

淀粉对硫化矿物和脉石矿物的选择性抑制作用及机理研究进展

随着我国对矿山环保力度的不断加强,绿色选矿药剂的研发显得尤为重要。淀粉以来源广、价格便宜、绿色、可再生和易降解等优势,常被用作黄铁矿、方铅矿、辉钼矿等硫化矿与角闪石、滑石、蛇纹石等硅酸盐矿物的抑制剂。本文介绍了淀粉的结构与性质,阐述了淀粉对不同硫化矿物及易浮脉石矿物的抑制作用及机理,以期学者们对淀粉展开深入研究,实现淀粉在选矿领域的广泛应用。     

铜铅硫化矿物浮选分离中铅抑制剂的研究进展

硫化铜铅矿石的浮选分离问题是矿物加工工程领域的热点和难点,文章针对浮选抑制剂的研究进展,从无机抑制剂、有机抑制剂、组合抑制剂和新型抑制剂四个方面,对硫化铜铅矿石浮选分离中铅抑制剂的研究成果进行了概述。分析指出,利用浮选药剂分子设计理论开发出新型铅抑制剂,使用组合抑制剂是未来硫化铜铅矿石浮选分离的重点研究方向。     

国外某复杂低品位铅锌矿选矿工艺优化及应用

某铅锌矿原矿铅含量为1.26%,含锌6.53%,含硫30.38%。生产上采用“铅锌依次优先浮选-中矿顺序返回”工艺流程,生产指标为铅精矿铅品位50.69%,含锌12.61%,铅回收率75.53%,锌精矿锌品位48.77%,含铅1.59%,锌回收率73.91%。铅锌互含较高,锌精矿指标不理想。为了解决该问题,本文在了解现场生产工艺流程及矿石性质的基础上,针对该铅锌矿开展了详细的选矿工艺优化试验,通过对部分药剂制度进行优化,采用特效捕收剂BK-LY11,同时在锌浮选回路采用中矿再磨工艺,显著改善了铅锌互含情况,有效提高了铅锌选别指标,并成功应用于生产实践,优化后获得的铅、锌回收率分别提高了5.83、8.46个百分点。     

The production of a lead glaze with galena: Thermal transformations in the PbS–SiO2 system

Galena, also known as PbS, was widely used in the production of lead glazes from the beginning of the 18th century to the second half of the 20th century. Although the PbO‐SiO₂ system has been studied for years, the PbS–SiO₂ phase diagram, involved in the formation of a glaze with galena, has not yet been investigated. Temperature transformations for the system 75 wt% PbS‐25 wt% SiO₂ are investigated in a high‐temperature resolved X‐ray diffraction experiment with synchrotron radiation and compared to those of the equivalent system 70 wt% PbO‐30 wt% SiO₂. Lanarkite, PbO·PbSO₄, is the phase predominantly formed as soon as galena decomposes during the heating. The results show that the system melts at a temperature higher than the PbO–SiO₂ system, but far lower than those expected for the PbO–PbSO₄–PbS system. A historical misfired lead glaze produced with galena is also studied. The presence of galena, lanarkite, and mattheddleite, Pb₁₀(SiO₄)_3.5(SO₄)₂Cl_2, is determined and discussed in terms of the composition of the galena mineral used and the firing conditions in light of the high‐temperature transformations previously obtained.     

Correlation between surface free energy and floatability of galena with potassium ethyl xanthate

From the maximal extrapolated film pressure π_max values for n-octane and n-propanol, the dispersion and non-dispersion components of the surface free energy of galena precoated with potassium ethyl xanthate (collector) were estimated and they were then correlated with the floatability of galena. The collector layer deposited by methanol evaporation did not produce any significant changes in the surface free energy of galena. Polymolecular adsorption of the collector occurred from aqueous solution. The adsorbed collector layer of ~8 statistical monolayers in thickness produced a considerable decrease in the dispersion component of the surface free energy and complete disappearance of non-dispersion interactions. At this surface coverage, a certain change in the properties of the adsorbed layer appeared which was probably connected with the formation of polymolecular layers containing dixanthogen. The work of the water adhesion being significantly lower than the work of water cohesion appeared insufficient to achieve a high floatability of galena.     

Galena-pyrolusite co-extraction in sodium chloride solution and its electrochemical analysis

The co-extraction behavior of galena-pyrolusite in a sodium chloride solution and the electrochemical mechanism of this process were investigated, and some factors affecting the leaching rate of Pb and Mn were optimized. The results show that all the factors such as the concentration of NaCl, HCl and pyrolusite ore, reaction time, temperature, adding times of HCl, affect the leaching rate of Pb. The main affecting factors are the concentration of NaCl, reaction time and temperature. The Tafel polarization curves and EIS plots of the galena and pyrolusite in the NaCl solution demonstrate that during the oxidation process of galena mineral electrode, film forms on the galena surface, which prevents galena from deeper oxidation. However, the film resistance can be greatly reduced in the presence of sodium chloride, thus promoting the reaction rate of galena.