Galvanic coupling and its effect on origin potential flotation system of sulfide minerals

The galvanic coupling formed in origin potential flotation systems of sulfide minerals can be divided into three types: sulfide mineral-sulfide mineral-water system; sulfide mineral-steel ball-water system; and sulfide mineral-sulfide mineral-collector system. In this paper, taking lead, zinc, iron sulfide mineral systems for examples,several models of galvanic coupling were proposed and the effects of galvanic coupling on flotation were discussed. A galvanic contact between galena (or sphalerite) and pyrite contributes to decreasing the content of zinc in lead concentrate, and enhances remarkably the absorption of collector on the galena surface. During grinding, due to galvanic interactions between minerals and steel medium, Fe(OH)3 formed covers on the cathodic mineral surface, affecting its floatability.     

利用磷灰石实现硫化矿浮选废水回用的试验评价

出于环境的考虑,越来越多的选矿厂均利用回水以减轻废水对环境的冲击和对水资源的依赖.工业生产经验表明,回水使用量的增加会对浮选带来不利的影响,尤其是对复杂矿化矿的优先浮选.浮选选择性降低的主要原因是溶液中重金属离子对闪锌矿或黄铁矿的意外活化.本文应用微型浮选试验,吸附试验和表面测试研究了利用磷灰石来实现硫化矿浮选废水回用的可行性.试验表明,磷灰石可增强对闪锌矿的抑制而提高浮选的选择性.微型浮选和表面测试表明,磷灰石与闪锌矿竞争吸附溶液中的重金属, 从而降低闪锌矿表面的重金属浓度.     

Potential control flotation of galena in strong alkaline media

The electrochemical oxidation of galena in collectorless and collector flotation systems, particularly in strong alkaline media, was studied. The results show that, with pH value higher than 12.5 and potentials below 0.17 V, the oxidation products of galena are elemental sulfur and HPbO2^- . Elemental sulfur was present on the mineral surface in excess of oxidized lead species due to dissolution of HPbO2^- , which is beneficial to the flotation of galena. Under the same conditions, sphalerite and pyrite were depressed as a result of significant surface oxidation. Diethyldithioearbamate (DDTC) was found to be the most suitable collector for galena flotation in strongly alkaline media. The very potential produced hydrophobic PbD2-the surface reaction produet of DDTC with galena, is 0 to 0.2 V. Meantime DDTC can depress the surface over-oxidation of galena.Investigations also indicate that, in the range of - 0.9 V to 0.6 V, hydrophobic PbD2 can be firmly adsorbed on galena.     

Effect of sodium pyrophosphate on the flotation separation of chalcopyrite from galena

The effect of sodium pyrophosphate (SPH) on the separation of chalcopyrite from galena was examined through flotation, adsorption, electrokinetic studies and infrared spectral analysis. Differential flotation tests indicate that satisfactory separation can be achieved within the pH range from 2.5 to 6 using SPH to depress the galena, but not the chalcopyrite when O-isopropyl-N-ethyl thionocarbamate (IPETC) is used as the collector. The electrophoretic mobilities of both the minerals dramatically become negatively charged following SPH adsorption in the pH range from 2.5 to 12. The infrared spectral analysis suggests that chemical adsorption occurs on galena surface treated by SPH, indicating that a chelate complex has formed. At weakly acidic pH values, the adsorption density of IPETC onto galena is significantly reduced in the presence of SPH. However, the amount of IPETC adsorbed onto chalcopyrite almost remains at the same level. Since the observed adsorption density of IEPTC onto chalcopyrite is quite high compared to galena, the observed flotation results are explained. A possible mechanism for the interaction between the two sulphide minerals and SPH is discussed.     

利用磷灰石实现硫化矿浮选废水回用的试验评价

出于环境的考虑，越来越多的选矿厂均利用回水以减轻废水对环境的冲击和对水资源的依赖．工业生产经验表明，回水使用量的增加会对浮选带来不利的影响，尤其是对复杂矿化矿的优先浮选．浮选选择性降低的主要原因是溶液中重金属离子对闪锌矿或黄铁矿的意外活化．本文应用微型浮选试验，吸附试验和表面测试研究了利用磷灰石来实现硫化矿浮选废水回用的可行性．试验表明，磷灰石可增强对闪锌矿的抑制而提高浮选的选择性．微型浮选和表面测试表明，磷灰石与闪锌矿竞争吸附溶液中的重金属，从而降低闪锌矿表面的重金属浓度．     

Effects of Metallic Ions on the Flotation of Spodumene and Beryl

Effects of multivalent metallic cations, such as Ca^2＋ and Fe^3＋, on the flotation of spodumene and beryl were studied. The results show that Fe^3＋ and Ca^2＋ exhibit efficient activation on the flotation of spodumene and beryl. The activation of Fe^3＋ happens quite well within a pH range of 6-9 while the concentration of Fe^3＋ is 35 mg/L. Efficient activation of Ca^2＋ takes place over at a pH over 11.6 at a concentration of 140 mg/L. The zeta potential of beryl and spodumene shifts slightly to positive values when activated by Ca^2＋, but markedly by Fe^3＋. New stretching frequencies of 1594.24 cm^-1 and 1587.13 cm^-1 have been found in the FTIR spectra of the two minerals after their interaction with Fe^3＋ and the collector. These new stretching frequencies are the asymmetric stretching frequencies of COO^- （carboxyl anion）, so thecollector may be chemically absorbed on the surface of Fe^3＋-activated beryl and spodumene.     

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.     

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.     

Depression behaviors of N-thiourea-maleamic acid and its adsorption mechanism on galena in Mo-Pb flotation separation

In present study, a novel organic depressant N-thiourea-maleamic acid (TMA) was synthesized and applied as a galena depressant in the flotation separation of Mo-Pb ores. The depression behaviors of TMA were tested through flotation experiments. A wider separation window for single minerals over 90.0% was obtained at 30.0 mg/L TMA, confirming that TMA could depress galena significantly, while effected molybdenite floatability slightly. An effective separation was obtained for artificially mixed minerals and actual Mo-Pb ores. The adsorption mechanism on galena was revealed by UV–Vis spectra, zeta potential tests, Fourier transform infrared spectroscopy (FT-IR) analysis, contact angle tests and X-ray photoelectron spectroscopy (XPS) analysis. The zeta potentials of galena became more negative and the contact angle of galena dropped from initial 74.36° to 57.8° with 30.0 mg/L TMA depressant, inferring that TMA had adsorbed on galena surface. The analysis results of UV–Vis spectra, FT-IR and XPS gave further evidence that TMA might chemisorb on galena surface via Pb sites on galena surface and the thiourea group in TMA molecular structure, while the carboxyl group played a role of hydrophilicity.     

桂北老堡铅锌矿床的成因研究

桂北老堡铅锌矿床位于扬子地台前寒武地块前陆盆地边缘的正向构造带上,产于震旦系陡山沱组白云岩和老堡组硅质岩中。矿石矿物成分简单,主要由闪锌矿、方铅矿、黄铁矿及少量黄铜矿等硫化物组成;脉石矿物主要由白云石、方解石、石英及少量绢云母、绿泥石等矿物组成。石英流体包裹体均一温度变化在115～270℃,盐度在（w（NaCl））3．8％～5．8％。流体包裹体的气液相成分显示,成矿流体富含CO2、CH4、C2H6,其中的W（Na^＋）／w（K^＋）、W（CI^-）/W（F^-）较高,且W（Na^＋）〉w（K^＋）〉w（Ca^2＋）〉w（Mg^2＋）。矿体中黄铁矿的δ^34S为12‰～21‰。与闪锌矿共生的石英的δ^18O为16．0‰-18．4‰,其中的流体包裹体δD为-58‰～-61‰。地质和地球化学特征表明,老堡为由热卤水与变质水或建造水混合的MVT型铅锌矿。     

DESIGNS AND APPLICATIONS OF COLLECTORLESS FLOTATION FLOWSHEETS OF SULPHIDE ORES~＋

ＤＥＳＩＧＮＳＡＮＤＡＰＰＬＩＣＡＴＩＯＮＳＯＦＣＯＬＬＥＣＴＯＲＬＥＳＳＦＬＯＴＡＴＩＯＮＦＬＯＷＳＨＥＥＴＳＯＦＳＵＬＰＨＩＤＥＯＲＥＳ~＋￥ＳｕｎＳｈｕｉｙｕ；ＬｉＢｏｄａｎ（ＤｅｐａｒｔｍｅｎｔｏｆＭｉｎｅｒａｌＥｎｇｉｎｅｅｒｉｎｇ，Ｃｅｎ?..     

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).     

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.     

Depressing effect of phenoxyl acetic acids on flotation of minerals containing Ca^2＋/Mg^2＋ gangues

Phenoxyl acetic acids were applied to determine their depressing effect on minerals containing Ca2 /Mg2 gangues. Calcite, mixture of calcite and fluorite, and nickel ore were used in the flotation. And the depression mechanism was studied by the determination of contact angle, zeta potential, adsorptive capacity of collector, and IR analysis as well. It is found that 0.1 mmol/L of phenoxyl acetic acid derived from pyrogallol or gallic acid exhibits strong depressing ability on calcite in almost zero yields at pH value of 9.8, and calcite can be depressed in the flotation of calcite/fluorite mixture for approximate 87% yield of fluorite. The flotation result of practical nickel ore containing serpentine indicates that these two depressants may also show better depression performance to serpentine than traditional depressants such as sodium fluosilicate and carboxylmethyl cellulose. Analysis for the depression mechanism reveals that there exists strong chemical interaction between the depressants and minerals.     

Selective separation of silica from a siliceous-calcareous phosphate rock

Selective separation of silica from a siliceous-calcareous phosphate ore that had been sieved into different size fractions is investigated by a combination of chemical analysis, zeta potential measurement and FTIR and XPS techniques. Scrubbing is a better choice than flotation for removing silica from the coarse fractions. The P2O5 grade of the coarse fractions is increased to about 30% by scrubbing and the product yields are higher than those obtained by flotation. The silica in the fine fraction is separated by reverse flotation. An alkyl amine salt (DAH) is an effective collector and the P2Os grade of the fine fraction can be increased by 7% to beyond 30% under acidic conditions. The higher zeta potential obtained using DAH suggests that it is more strongly absorbed onto the ore panicles than the other cationic collectors.FTIR and XPS results confirm physical absorption of the cationic collector onto the ore surface. They also indicate that calcite is dissolved at low pH values, which increases the Si concentration on the ore 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.     

广东凡口铅锌矿床主要金属矿物的标型特征及其成因意义

广东凡口铅锌矿床的主要金属矿物黄铁矿、闪锌矿和方铝矿均可分为四个世代。各世代的主要金属矿物的标型特征差异很大。黄铁矿的Co/Ni比值,闪锌矿的颜色、晶胞参数及Fe、Mn、Cd含量,方铝矿的Mn、Ag、Sb、Bi含量均随其世代不同而有规律地变化。该矿床属沉积-成岩、地下热水改造型的层控铅锌矿床。     

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。     

胍基阳离子捕收剂反浮选磷矿的性能与机理分析

为了研究磷矿反浮脱硅过程中,胍基阳离子磷矿捕收剂的作用机理,以N-椰油基-1,3-丙撑二胺、单氰胺、乙酸为原料制得一种阳离子表面活性剂,并用于傅里叶红外光谱仪表征,测试了该药剂与3种矿物作用前后的接触角、Zeta电位、红外光谱,进行了石英、白云石、胶磷矿的纯矿物浮选试验等。结果表明:该合成药剂属胍基阳离子表面活性剂,在广泛pH值范围内,对石英的捕收能力较强,对白云石次之,对胶磷矿较弱;在弱碱性下,对白云石捕收性能有所提高;相较白云石、胶磷矿,该药剂更易与石英产生吸附作用,使矿物表面呈现疏水性;接触角、Zeta电位、红外光谱测试结果说明与3种矿物的吸附主要是物理吸附。试验结果说明该胍基阳离子表面活性剂可以作为磷矿反浮脱硅捕收剂。     

Flotation of kaolinite and diaspore with hexadecyl dimethyl benzyl ammonium chloride

Tertiary amine was synthesized from fatty amine and formaldehyde. And then the synthesized tertiary amine was used to react with benzyl chloride to synthesize hexadecyl dimethyl benzyl ammonium chloride （1627） at ambient pressure. Using the synthesized 1627 as collector,the flotation properties of diaspore and kaolinite were investigated by single mineral and mixed mineral test. The flotation mechanism of diaspore,kaolinite and 1627 was discussed based on FTIR spectra. The results show that the mass ratio of aluminum to silicate achieves 15.02 and the recovery of alumina in concentrate is 43.07% using 1627 as a collector. The 1627 is found to be a more effective and a promising collector for reverse flotation to remove aluminum-silicate minerals from bauxite.