Influence of liquid phase and products of its radiolysis on surface properties of pyrite and arsenopyrite

A feasibility study has been made on improving the contrast of processing properties of pyrite and arsenopyrite, irradiated by accelerated electrons, when these minerals are in the form of neutral, weakly alkaline, and alkaline aqueous suspensions. It has been shown that as a consequence of change in the surface composition, sorption species, and quantity of adsorbed xanthate and its derivatives, the contrast of flotation properties of pyrite and arsenopyrite can be increased by regulating the irradiation dose of the mineral suspension. Institute of Problems of Complex Development of Bowels, Russian Academy of Sciences, Moscow. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 85–91, January–February, 1999.     

Correlation between elemental composition of the surface of gold-bearing pyrite and arsenopyrite and their sorption and flotation properties

Conclusions  1. Crystallostructural estimate of the ionicity of the Fe-S bond in pyrite and arsenopyrite suggests possible shifting of the pyrite electrons toward the anionic core, and this is responsible for the higher reactivity of pyrite vis-à-vis arsenopyrite. 2. The differences in the floatability of pyrite samples from different deposits are caused essentially by the state and elemental composition of the surface. 3. With rise of arsenic content as we go from pyrite to arsenopyrite, mineral extraction falls, and in gold-bearing arsenous minerals the minimum flotation activity corresponds to the maximum gold content. Institute of the Problems of Integrated Exploitation of Mineral Resources, Russian Academy of Sciences, Moscow. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, Vol. 33, No. 6, pp. 110–115, November–December, 1997. This work was carried out with the support of the Russian Fund for Fundamental Research (Project No. 97-05-64010).     

Nanosecond electromagnetic pulse effect on phase composition of pyrite and arsenopyrite surfaces,their sorption and flotation properties

The X-ray photoelectronic spectroscopy data give the grounds for statement that the powerful nanosecond electromagnetic pulse pretreatment improves sorption activity of pyrite surface and lowers sorption of a collector at arsenopyrite surface. The research results are verified by test data on the powerful nanosecond electromagnetic pulse effect on the structure and chemical properties of pyrite and arsenopyrite surface, as well as their electrochemical and flotation properties.     

New complexing agents to select auriferous pyrite and arsenopyrite

The authors propose the process for selective flotation of auriferous pyrite and arsenopyrite, where the combination of xanthate, 2-hydroxylpropyl ester of diethyldithiocarbamate acid (HPEDEDCA) and oak-bark extract (OBE) is used to produce pyrite concentrate recovered into the froth product. The process provides the selective recovery of valuables into heteronymous concentrates, thus reducing the irrecoverable valuable component loss by 5–7 %. The complexing capacity of HPEDEDCA to gold is experimentally proved and allows using it as a selective collector of auriferous iron sulfides. The use of OBE to depress iron sulfides and arsenic in flotation of multicomponent ores contributes to higher flotation selectivity and grade of heteronymous concentrates.     

联合使用碱和氧化剂分离毒砂与黄铁矿

本文提出了碱和氧化剂联合使用的方法分离毒砂与黄铁矿,并对其作用机理进行了研究。结果表明,氧化剂氧化后的硫化矿物,表面特性及可浮性发生了很大的变化,在碳酸钠作用下,可以实现毒砂和黄铁矿的分离。这主要是由于氧化剂选择性氧化抑制毒砂的同时,碱选择性地阻碍捕收剂在毒砂表面的吸附,并清洗黄铁矿表面因氧化而生成的不利于浮选的氧化产物。在该条件下,矿物表面的氧化产物和无碱时相同。     

Influence of nanosecond electromagnetic pulses on electrophysical properties of pyrite and arsenopyrite

The present investigation concerns influence of high power nanosecond electromagnetic pulses on thermoelectric properties, conduction and electrode potential of pyrite and arsenopyrite, Darasunskoe deposit. Experimental data obtained are in full compliance with classical concepts on interrelation between electrochemical and flotation properties of minerals.     

Response of rough and acute surfaces of pyrite with 3-D approach to the flotation

This study presents a new 3-D approach to determine the morphological properties of pyrite particles by Brunauer — Emmett — Teller (BET) nitrogen gas adsorption and Permaran methods. The obtained parameters, which are surface roughness and acuteness, were correlated with the floatability of those mineral particles. The flotation performances of the pyrite particles ground in different mills were also evaluated by a Hallimond tube. The results showed that lower roughness and acuteness values caused higher flotation recoveries for the pyrite particles considered. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 4, pp. 95–104, July–August, 2006     

Electrokinetic properties of pyrite,arsenopyrite and quartz in the absence and presence of cationic collectors and their flotation behaviour

This paper contains the results of Hallimond tube flotation tests conducted with pyrite arsenopyrite and quartz using a cationic type collector called hexyl thioethylamine, as well as the results of electrophoretic mobility (E.M.) tests for the same minerals measured under various conditions. The purpose of this study is to investigate the effect of surface charge of sulphide minerals on the attachment mechanism of a cationic collector. In this regard, the influence of pH and collector concentration on the electrophoretic mobilities of pyrite, arsenopyrite and quartz were monitored. The mobility measurements at various pH values were made in the absence and presence of collector, and the effect of collector concentration on the electrophoretic mobility was determined at constant pH. The results were evaluated in terms of flotation, electrophoretic mobility, adsorption and IR data. The experimental results indicate that flotation of pyrite induced by hexyl thioethylamine is not dependent on the surface charge of the particle.     

利用反浮选对黄铁矿进行脱砷研究

硫砷分离一直是选矿界所面临的难题之一。本文研究了氧化钙、铜离子、栲胶及丁基黄药对黄铁矿和毒砂单矿物浮选的影响 ,提出了抑硫浮砷的分离方案 ,并利用实际高砷硫精矿进行验证 ,取得了一定效果 ,为黄铁矿脱砷提出了一条新思路。     

Finely Dispersed Micro- and Nano-Gold Recovery Using Thermomorphic Polymer with Diphenylphosphine

The article reports test data on adsorption and flotation characteristics of thermomorphic polymer joined with diphenylphosphine—TMPD. The test materials are natural pyrite and arsenopyrite, and models of gold-bearing sulfide minerals. Electron microscopy and X-ray structure analysis prove that reductive adsorption of gold at the surface of sulfide minerals from HAuCl₄ solution allows modeling natural aggregates of sulfides and finely dispersed gold. UV spectrophotometry proves selective adsorption of TMPD at gold. Laser scanning microscopy shows connection of TMPD with micro- and nano-size gold on polished sections of pyrite and arsenopyrite. During monomineral flotation, joint use of TMPD and butyl xanthate at a ratio of 1:1 doubles the yield of gold-bearing sulfides and enables maximum recovery of gold minerals at the total consumption of reagents reduced by 30–50%. It is found that TMPD is selective relative to gold-bearing minerals and its combination with xanthate ensures a considerable increment in gold-bearing mineral recovery by flotation.     

Effect of ozone on physico-chemical and flotation properties of surface of pyrrhotite under the nanosecond electromagnetic pulse treatment

It is proved by testing that the effect of nanosecond powerful electromagnetic pulses (PEMP) tends to give rise to both pyrrhotite disintegration and alterations of its particles’ surface chemistry. It is found that PEMP exerts an effect on the surface composition, floatability, sorption ability and solubilization intensity of pyrrhotite. The non-monotone variation of sulphur content, removed from pyrrhotite surface under hexane action, and ferrous and ferric sulfates detected in the aqueous phase of suspension, are found to induce a nonmonotone alteration of sorption and flotation properties of the mineral depending on the number of pulses. The mode has been established for the preliminary PEMP treatment for pyrrhotite and pentlandite, aimed at improving the flotation separation as compared to a conventional mode. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 91–99, January–February, 2007.     

On regularities observed in formation of liquid phase composition in flotation sulfide pulp

It is shown that modifiers decrease oxidation of pyrite following the line: cyanide > thiosulphate > sulfite > sulfide > dioxide. Action of the modifiers shows itself weaker for other sulfide minerals. The mode of selective flotation of cooper-zinc, copper-pyritic and other products has been developed with allowance for this fact. Iron powder and ferrous iron, as fine reducing agents, advantage to saving the natural surface of a sulfide mineral and improving the flotation selectivity. Decrease in the concentration of copper in liquid phase, that activates sphalerite, and stabilization of anionic composition depend on the mode of pulp conditioning by grinding and flotation, based on the use of various modifiers, their feeding points and pH of the medium. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 108–119, January–February, 2007.     

Effect exerted by structural features of copper-zinc ores on their oxidation and technological properties

Modeling the oxidation of pyrite copper-zinc ores under evaporization shows that structural features of ores influence the process kinetics, and displays new-formed mineral phases, namely, gannigite, biankite, chalcanthite, which relate with sulfate generating on evaporation from natural and process waters at pyrite deposits. The oxidation effect on the mineral flotation properties is described. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 4, pp. 101–110, July–August, 2008.     

Flotation behavior of sulfides on mechanical activation

Mechanical activation during grinding affects the flotability of pyrite, arsenopyrite, and galena. It is established that the S, Fe, and As atoms at the surfaces of the initial materials are mainly in the oxidized state. The transformations occurring on the surfaces of mechanically activated sulfide minerals are the cause of the changes in flotability. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 102–106, January–February, 2000     

The influence of the oxidation state of pyrite and arsenopyrite on the flotation of an auriferous sulphide ore

In this paper, the influence of the oxidation state of pyrite and arsenopyrite on the flotation of an auriferous sulphide ore was investigated by different techniques, including electrode, pulp potentials, DRIFT spectroscopy and microflotation tests. In addition, the gold and sulphide recoveries were also investigate, in a laboratory-scale cell, as a function of pulp potential and reagent concentration. It was verified that the presence of oxidation products on the sulphide mineral surface demands a higher collector concentration in order to achieve a satisfactory sulphide recovery. The electrochemical behaviour of pyrite and arsenopyrite indicated that a nitrogen atmosphere can lead to a low pulp potential, which inhibits the formation of oxidation products, enhancing both the free gold and sulphide recoveries. Although copper sulphate activates even oxidised sulphide surfaces, it does not improve free gold recovery.     

硫化矿物表面氧化的研究

通过热力学计算、矿物电极电位测定、循环伏安曲线和浮选试验,研究了方铅矿、黄铜矿、砷黄铁矿和黄铁矿表面的氧化反应。主要分为两大类:生成中性硫(S~0)的氧化反应和生成硫氧阴离子(S_xO_y~(2-))的氧化反应。前者能诱导矿物表面疏水,实现无捕收剂浮选(亦称自诱导浮选);后者导致矿物表面亲水。电位,pH和矿物的电子结构是调控硫化矿物表面阳极氧化的主要因素。     

Enhanced nonferrous and noble metal recovery in scheelite-sulfide ore flotation with Aeroflot reagents

The flotation properties of new dialkyldithiophosphates (BTF-163, BTF-175) are compared with the standard basic Aeroflot reagent IMA-I413 and butyl xanthate during flotation of scheelite-sulfide ore. The selectivity of the test Aeroflot reagents in separation of chalcopyrite, magnetic pyrite, pyrite and arsenopyrite is illustrated in the article together with the option of enhanced extraction of copper and noble metals with the reduced arsenic content of the copper concentrate. The best results are obtained with BTF-163 that is recommended to industrial testing.     

一种新型有机抑制剂对铁闪锌矿与毒砂浮选分离的影响研究

考察了铁闪锌矿和毒砂的浮选行为以及Cu²⁺和有机抑制剂PALA对它们可浮性的影响。结果表明, 以丁黄药作捕收剂, 2^#油为起泡剂, 铁闪锌矿和毒砂具有相似的可浮性。硫酸铜可大大改善铁闪锌矿的可浮性, 而Cu²⁺对毒砂的活化作用较小。PALA对铁闪锌矿和毒砂在不同矿浆pH值下都有一定程度的抑制能力, PALA对毒砂的抑制能力大于对铁闪锌矿的抑制能力。Cu²⁺和PALA的共同作用能使铁闪锌矿和毒砂得到有效的分离。人工混合矿浮选分离试验结果表明, 以丁黄药为捕收剂、硫酸铜为活化剂、PALA为抑制剂, 2^#油为起泡剂, 铁闪锌矿和毒砂得到有效的分离, 泡沫精矿产品中含锌40.40%, 锌回收率达95.41%, 槽内产品含砷40.33%, 砷回收率达85.27%。通过动电位分析了药剂在矿物表面的作用机理。     

Application of complexing reagents to flotation separation of the varieties of pyrite

It is considered how the organic reagents, complexing agents, change floatability of the varieties of pyrite with different content of goal. The authors continue studying the flotation effect of the reagent PROX capable to selectively decrease floatability of some pyrite varieties in the presence of xanthogenate due to formation of a hydrophilic complex compound with ferric iron at the phase interface of the mineral surface — liquid, and to reduce sorption of xanthogenate. A phytogenous reagent is suggested as an alternative to the multi-component PROX. The new reagent mechanism is described by examining the chromatographic behavior of the compound of this reagent and ferric iron salt. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 4, pp. 111–120, July–August, 2007.     

Effects of free cyanide and cuprous cyanide on the flotation of gold and silver bearing pyrite

At gold and silver mineral processing plants, cyanide species are always present in the process water recycled to flotation circuits, despite the cyanide destruction process. The effect of cyanide, in particular, cuprous cyanide on gold and silver flotation has not been well understood. In the present study, free cyanide and cuprous cyanide species were isolated and their effects on the flotation of a pyritic ore were evaluated. It was found that free cyanide depressed gold and silver flotation through their carrier, pyrite. Cuprous cyanide mainly in the form of Cu(CN)₃²⁻ depressed pyrite flotation similarly as free cyanide. Electrochemical studies including open circuit potential (OCP), cyclic voltammetry and electrochemical impedance spectroscopy (EIS) techniques were carried out to understand the underpinning depression mechanism of cyanide species on pyrite flotation using xanthate as collector. It was found that all surface electrochemical reactions were inhibited by either free cyanide or cuprous cyanide. The surface layer as a result of xanthate adsorption on pyrite was completely removed in the presence of these cyanide species, which was suggested to contribute to the hydrophilic pyrite surface.