Electrochemical flotation of diethyldithiocarbamate-pyrrhotite system

Using sodium diethyldithiocarbamate as a collector the flotation behavior of pyrrhotite was investigated.The relationship between potential and pH range for pyrrhotite flotation was established. The results show that the flotation of pyrrhotite is dependent on pulp potential at certain pH values. Pyrrhotite has good floatability from pH 2 to pH 12, and poor flotability at pH＞12. Cyclic voltammetry and Fourier transform infrared spectrum analysis show that the major adsorption product of DDTC on pyrrhotite is tetraethylthiuram disulfide. The intensity of Fourier transform infrared signals of tetraethylthiuram disulfide adsorbed on pyrrhotite and the anode current of a pyrrhotite electrode and flotation response of pyrrhotite are correlated with pulp potentials.     

Hydrophobic-surface of copper from converter slag in the flotation system

The converter slag from a smeltery in Daye contains 2.01% copper. The floatability of copper has a significant influence on the flotation of converter slag. Flotation tests, contact angle tests and FTIR were conducted to assess the influences of pH and different flotation concentrators on its hydrophobic process, mechanism and flotation. The results show that since chemisorptions are formed on the surface, hydrophobicity of copper is highly enhanced by xanthate, butylamine dithiophosphate and Z-200. The hydrophobic-surface of copper becomes worse with low recovery in strong acid and alkali situation. When pH value is 10, butylamine dithiophosphate and butyl xanthate are used as the mixed-collector, the grade of copper is 40.01% and that of tailings is 0.37%.     

Synthesis of glycerine-xanthate and its depressing mechanism in separation of marmatite from arsenopyrite

A small molecular organic depressor glycerine-xanthate was synthesized. The effect of glycerine-xanthate on the flotation of sulfide minerals was investigated based on a function of pH value and concentration of glycerine-xanthate through flotation experiments in the presence and absence of Cu^2＋. The results show that glycerinee-xanthate has a strong dressing effect on marmatite at pH〉6 and on arsenopyrite in weak acid and base conditions with butyl-xanthate as collector. In the presence of glycerine -xanthate, marmatite is activated by addition of Cu^2＋, but arsenopyrite cannot be activated and remains unfloatable. So the selective separation can be achieved for two minerals. The depression of glycerine-xanthate on sulfide minerals was discussed based on the radical electronegative calculation and the theory of HSAB. Infrared spectrum shows that there are some -OH and-CSS-in glycedne-xanthate molecule, which competes with butyl-xanthate on the mineral surface. As a result of many hydrophilic groups in glycerine-xanthate, the surfaces of marmatite and arsenopyrite become hydrophilic, thus the flotation of marmatite and arsenopyrite is depressed. The collector is adsorbed preferentially on the surface of marmatite and it shows a better floatability in the presence of Cu^2＋, whereas, the surface of arsenopyrite absorbs glycerine-xanthate and the flotation of arsenopyrite is depressed by glycerine-xanthate.     

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.     

A review of flotation and selective separation of pyrrhotite: A perspective from crystal structures

Pyrrhotite is an associated mineral that exists widely in sulfide ore. The presence of pyrrhotite will affect the recovery of platinum group minerals. Therefore, researchers have paid increasing attention to the flotation separation of pyrrhotite. Pyrrhotite superstructures owning different Fe/S ratios results in various crystal structures, corresponding to different physical, chemical and electronic properties, and consequently different flotation behavior. In the present paper, a comprehensive review is conducted to discuss the influence of crystal structures on the natural floatability, mineral-reagent interaction, surface oxidation and flotation electrochemistry of pyrrhotite. The selective flotation process of pyrrhotite from its associated minerals is also reviewed in this paper. It is hoped that this review can summarize the newly published research results combined with some representative results from the past, to provide a theoretical basis for the study of the flotation mechanism of pyrrhotite and provide a new direction for future research on pyrrhotite.     

Relative floatability as a criterion for evaluating the separation performance of phosphate from iron

This work was aimed to study the relative floatability of phosphate flotation by means of kinetic analysis.The relative floatability is important to determine how selectively the phosphate is separated from its impurities. The effects of pulp pH, solid content, reagents dosage(depressant, collector and co-collector) and conditioning time were investigated on the ratio of the modified rate constant of phosphate to the modified rate constant of iron(relative floatability). The results showed that a large dosage of depressant associated with a low value of collector resulted in a better relative floatability. Increasing the co-collector dosage, conditioning time and pH increased the relative floatability up to a certain value and thereafter resulted in diminishing the relative floatability. Meanwhile, the results indicated that increment of solid concentration increased the relative floatability in range investigated. It was also found that that maximum relative floatability(16.05) could be obtained in pulp pH, 9.32, solid percentage, 30,depressant dosage, 440 g/t, collector dosage, 560 g/t, co-collector dosage, 84.63 g/t and conditioning time,9.43 min.     

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.     

方铅矿磨矿体系表面电化学性质及其对浮选的影响

采用电化学测试技术研究方铅矿磨矿体系中磨矿介质类型（瓷介质和铁介质）、机械力以及捕收剂对方铅矿表面电化学性质的影响。研究结果表明：瓷介质中,方铅矿表面会发生适当的氧化反应,有利于方铅矿浮选：增大方铅矿与瓷介质间的机械力,体系的还原性增强,同时削弱矿物表面的氧化反应,给浮选造成一定影响。铁介质中,一方面,由于铁与方铅矿的腐蚀电偶作用增强了体系的还原性,降低了药剂在方铅矿表面的吸附性能,另一方面,由于腐蚀电偶作I用产生的铁离子增强了方铅矿表面的亲水性,两方面的影响都不利于方铅矿的浮选;增大方铅矿与铁介质间的机械力,二者之间的腐蚀电偶作用和体系的还原性增强,同样不利于方铅矿浮选。当pH=9时,在瓷介质和铁介质磨矿体系中是否添加捕收剂,对方铅矿表面电化学性质和浮选影响不大。     

Exploration of amino trimethylene phosphonic acid to eliminate the adverse effect of seawater in molybdenite flotation

In this investigation, a chelating agent of amino trimethylene phosphonic acid (ATMP) was introduced to eliminate the adverse effect of seawater in molybdenite flotation. Microflotation results presented that high flotation recovery of molybdenite was achieved in freshwater using kerosene as the collector, but it was significantly decreased in the presence of seawater when pH > 9.5. Among the main ions in seawater, magnesium and calcium ions played a more detrimental role than others. After the addition of ATMP, molybdenite floatability can restore in seawater. Zeta potential distribution and solution chemistry calculation results illustrated that the decreased molybdenite floatability was attributed to the interaction of positive Mg(OH)_2(s) (major) and CaOH⁺ (minor) components with the molybdenite surface. The magnesium/calcium ions of positive components of Mg(OH)_2(s) and CaOH⁺ interacted with the ionized species of ATMP and then produced ATMP-calcium/magnesium complex, leading to the electrostatic repulsion between molybdenite and ATMP-calcium/magnesium complex that was restoring the molybdenite flotation. Hence, the ATMP can be utilized as an appropriate reagent to improve molybdenite flotation in seawater.     

The pulp electrochemistry of flotation separation for stibnite-arsenopyrite bulk concentrate

In the thermodynamics, for flotation separation of the Sb-As bulk concentrate system there is no potential extent using butyl xanthate as collector. However in the kinetics, there exists 150 mV in reducing potential of butyl dixanthogen on the surface of stibnite and arsenopyrite. In this paper, their reducing kinetic difference of electrochemistry was confirmed by pure mineral flotation under controlled potential, the artificial Sb-As bulk concentrate flotation separation and UV-spectrophotometic analysis. The electrochemical separation of Sb-As bulk concentrate has been carried out. qualified concentrate has been obtained. Sb-concentrate contains Sb 49.44 %, As 0.44 %, Sb-recovery is 87.83 % and As-concentrate contains As 10.96 %, As-recovery is 94.66 %. Synopsis of the first author Ou Leming, Doctoral student, born in May 1964, majoring in the flotation electrochemistry of sulphide minerals and the potential-control flotation column.     

Flotation de-silicating from diasporic-bauxite with cetyl trimethylammonium bromide

1　INTRODUCTIONTheZetapotentialsofkaolinite ,illiteandchlo riteweremeasuredforthecoalflotation ,allthesethreeclaymineralswerenegativelychargedinthepHrangeof 2 .5 11.0 [1] .Theadsorptionofsodiumdode cylsulfateanddodecyltrimethylammoniumchlorideontokaolinitewasstudiedintheabsenceandpresenceofsodiumhexametaphosphate .Itwasfoundthatthepresenceofthelongchainphosphatedecreasedad sorptionoftheanionicsurfactantbutincreasedthead sorptionofthecationicsurfactant[2 ] .Acommercialmonoetheramineandac…     

改性高钛高炉渣的浮选性能

以攀钢高炉渣为原料,采用＂选择性分离与长大＂的方法使高炉渣中的钛富集于钙钛矿中,然后在常温25℃,pH值9.3下,研究捕收剂油酸、捕收剂A与抑制剂水玻璃、CMC的用量对改性高炉渣中钙钛矿浮选性能的影响.实验结果表明：捕收剂油酸和捕收剂A都能用于改性渣的浮选,但是捕收剂A浮选性能更佳;抑制剂水玻璃和CMC都能抑制脉石,但是水玻璃也抑制钙钛矿浮选,所以CMC更适用于改性高炉渣的浮选.本实验优化出最佳浮选工艺,即为捕收剂A用量600 g/t,CMC用量为1 500 g/t时,浮选效果最为理想.此选冶结合的绿色分离技术适宜于攀钢含钛高炉渣的综合处理.     

细粒难选锐钛矿浮选试验研究

对TiO2品位为10.97%的某细粒复杂难选锐钛矿进行浮选试验研究.研究表明,试样磨矿细度为-0.043 mm占85.96%时,以碳酸钠将pH调至8.5,粗选采用羧甲基纤维素和氟硅酸钠为组合抑制剂,精选采用硫酸铝和淀粉为组合抑制剂,用乙酸铅作活化剂,用苄基胂酸和羟肟酸钠作组合捕收剂,经两次粗选、三次精选的浮选工艺,可得到产率为28.51%、TiO2品位为30.91%、回收率为80.32%的锐钛矿精矿,初步实现了细粒难选锐钛矿的选矿富集,为该矿的进一步深入研究及开发奠定了一定的基础,同时为伴生的V、Cr、Co等稀土元素的综合回收利用提供了一定的参考.研究结果表明：①锐钛矿的可浮性与金红石相似,Pb2＋离子同样是锐钛矿浮选的有效活化剂;②对嵌布粒度细、矿物组成复杂的难选矿,药剂的组合使用是使目的矿物以连生体的形式浮选富集的有效手段.     

Effect of butanol on flotation separation of quartz from hematite with N-dodecyl ethylenediamine

In order to investigate the effect of butanol on quartz flotation when N-dodecyl ethylenediamine(ND)was used as collector, single mineral flotation and artificial mixed mineral(hematite and quartz were mixed at a mass ratio of 3:2) separation were conducted in the laboratory. Experimental results indicated that addition of butanol could improve the collecting performance of ND on quartz and enhance the floatability of quartz. Best flotation recovery of quartz was obtained when butanol was mixed with ND at a mass ratio of 1:1. Moreover, the molecular structure of alcohols had a significant effect on mineral recovery. Best separation efficiency could be obtained when tert-butanol was added as it had the largest cross-sectional area. Zeta potential measurements indicated that alcohols could strengthen electrostatic adsorption between quartz and collector. Molecular dynamic simulations revealed that co-adsorption of alcohols along with ND had taken place on the quartz surface, and ND/tert-butyl combinations were more easily absorbed on the quartz surface.     

改性脂肪酸对磷矿的浮选

改性脂肪酸XF-1是一种新型的磷矿捕收剂.为了考察XF-1对磷矿的浮选效果,选取XF-1、磺化油酸钠及油酸钠为捕收剂对宜化磷矿进行浮选,动电位及单矿物吸咐对比分析表明,在捕收剂用量为1.5kg/t,浮选温度为30℃时,XF-1、磺化油酸钠和油酸钠将五氧化二磷品位为21%的粗磷矿分别提升到27%、23.6%、22.1%,磷回收率分别为85%、75.4%、74.8%;在低温15~25℃时,XF-1浮选获得磷矿品位和磷回收率明显高于磺化油酸钠和油酸钠.采用粗选与精选相结合的闭路浮选工艺,捕收剂XF-1选别出品位为30%、磷回收率为90%的磷精矿,且精矿氧化镁含量只有1.4%.XF-1所表现出的亲和力和吸附力优于磺化油酸钠和油酸钠,XF-1具有良好的捕收性能.     

Effect of galvanic contact on the flotability of galena in the presence and absence of a collector

In this paper, the effect of various electrochemical environments in the galena flotation is investigated. The electrochemical environments consisted of a ball mill for grinding of galena ore and a Denver flotation cell for flotation of galena in the laboratory scale. In order to achieve the maximum recovery with sodium hyposulfite, the concentrations of 0.06 and 0.12 M of air and nitrogen gases have been used to control the pulp potential in the Denver flotation cell. The galena sample was from the “Era mine” which is located in the Kiyasar area, north of Iran. This mine contains: Galena (PbS) at least 22%, Fluorite (CaF₂) 73.37%, Quartz (SiO₂) 2.54% and other minerals such as Cerussite (PbCO₃) and Kaolinite (Al₂Si₂O₅(OH)₄). Flotation of Galena was conducted in a 0.12 M of sodium hyposulfite solution. It was found that the amount of recovery by this process was 85% and 63% in the presence and absence of potassium amyl xanthate (KAX) and at an estimated potential of 280 to 350 mV respectively while the recovery was 70% and 52% at an approximate potential of 175 to 210 mV in water in the presence and absence of collector (KAX).     

HYDROPHOBICITY－HYDROPHILICITY BALANCE RELATIONSHIPSFORCOLLECTORLESSFLOTATIONOFSULPHIDEMINERALS

ＨＹＤＲＯＰＨＯＢＩＣＩＴＹ－ＨＹＤＲＯＰＨＩＬＩＣＩＴＹＢＡＬＡＮＣＥＲＥＬＡＴＩＯＮＳＨＩＰＳＦＯＲＣＯＬＬＥＣＴＯＲＬＥＳＳＦＬＯＴＡＴＩＯＮＯＦＳＵＬＰＨＩＤＥＭＩＮＥＲＡＬＳＨＹＤＲＯＰＨＯＢＩＣＩＴＹ－ＨＹＤＲＯＰＨＩＬＩＣＩＴＹＢＡＬＡ...     

Theoretical study of 2-mercaptobenzimidazole derivatives as chelating collectors in flotation separation of galena and pyrite

Three 2-mercaptobenzimidazole derivatives, 1-ethyl-2-mercapto-benzimidazole (EMBI), 1-propyl-2-mercapto-benzimidazole (PMBI) and 1-benze-2-mercapto-benzimidazole (BMBI), were designed and synthesized in the paper, and their collecting behavior in flotation separation process of galena over pyrite was investigated by flotation tests on lab scale. Apart from this, density functional theory (DFT) calculation and molecular dynamics (MD) simulation were also used to elucidate their collecting mechanism. Results of flotation tests indicate that separation of galena over pyrite is feasible at pH 10, and BMBI has the best floatability among three collectors. DFT calculations show that BMBI has the highest occupied molecular orbital (HOMO) energy and strongest collecting efficiency. The adsorption mode of three collectors on mineral surface by MD method indicates that the combination processes of collectors with mineral are exothermic, and the higher the binding energy, the firmer the collector adsorbs on the mineral surface and the higher collecting capacity. The calculation results demonstrate that the floatability of three collectors follows the order: BMBI > PMBI > EMBI, which is highly consistent with the flotation tests.     

Growth of covellite crystal onto azurite surface during sulfurization and its response to flotation behavior

In this work, the growth of copper sulfide crystal onto azurite surfaces during sulfurization and its response to flotation are investigated. Filed emission scanning electron microscopy-energy dispersive X-ray spectroscopy (FESEM) and X-ray diffraction (XRD) studies confirmed that the sulfurization of azurite is not limited to the mineral surface, but rather penetrates into the bulk to form covellite crystal (syn-CuS), creating favorable conditions for the stable adsorption of xanthate and greatly promoting the azurite flotation. Additionally, as demonstrated by X-ray photoelectron spectroscopy (XPS) and time of flight secondary ion mass spectrometry (TOF-SIMS) analyses, a redox reaction occurred during this process, and Cu(Ⅱ) onto the mineral surface was reduced to Cu(I). Correspondingly, reduced S^2- was oxidized to (S₂)^2-, (S_n)^2-, and even to deeper oxidation state S⁰, (S_xO_y)^n- and SO₄^2-. Excess sodium sulfide strengthens copper sulfide to form onto the azurite surface, and provides enough raw material for crystal copper sulfide to grow, resulting in the formation of “flake-like” covellite with a better crystallinity. However, the floatability of azurite decreased dramatically under this condition, because the generated massive colloidal copper sulfide in flotation pulp deteriorates the flotation environment, resulting in a decreased effective adsorption of collector onto azurite surfaces.     

铝硅酸盐矿物新型浮选捕收剂的研究

考察了自行合成的新型阳离子表面活性剂QAS222对高岭石、叶蜡石和伊利石等铝硅酸盐矿物的浮选行为,试验研究结果表明：广泛矿浆pH范围内,新型阳离子表面活性剂QAS222对铝硅酸盐矿物既表现出较强的捕收力,又显示良好的选择性,是铝硅酸盐矿物的有效捕收剂,可应用于铝硅酸盐矿物的浮选富集,同样也可用于铝土矿、铁矿、萤石矿等选别过程的反浮选脱硅;在矿浆pH=11时,以QAS222为捕收剂,不添加其它任何抑制剂,成功地实现不同铝硅比的人工混合矿的反浮选脱硅,并获得较好的选别指标——当给矿A/S仅有2．7时,仍能获得精矿A／S为12．82,其中Al2O3品位77．79％、回收率69．91％的较好指标,且当给矿A／S不断增大时,精矿中的A/S,Al2O3的品位和回收率都有所提高．