Interaction of pentlandite,chalcopyrite, and pyrrhotine with elementary sulfur: I. Sulfidizing of pentlandite

The first part of the study into the sulfidizing of the major minerals of copper-nickel ores, namely, pentlandite, chalcopyrite, and pyrrhotine, by elementary sulfur is presented. The phase composition of the sulfidizing products is determined by scanning electron microscopy and electron-probe microanalysis and is then used to propose a mechanism for the sulfidizing of pentlandite under near-equilibrium conditions.     

Interaction of pentlandite, chalcopyrite, and pyrrhotine with elementary sulfur: II. Sulfidizing of chalcopyrite

The results of the second part of the study into the sulfidizing of the main sulfide minerals of copper-nickel ores, namely, pentlandite, chalcopyrite, and pyrrhotine, by elementary sulfur are presented. The phase compositions of the sulfidizing products are examined by scanning electron microscopy and electronprobe microanalysis, and a mechanism is proposed for the sulfidizing of chalcopyrite under near-equilibrium conditions.     

Effect of the trivalent iron content in a pyrrhotine concentrate on the reaction mechanism of its sulfuric acid leaching

The laws of atmospheric sulfuric acid leaching of pyrrhotine concentrate are analyzed as a function of the redox potential of a reaction system, which is determined by the Fe(III) content in a solution.     

Kinetic investigation of sulfidizing annealing of scorodite in processing of refractory oxidized gold-containing ores

The results of kinetic studies on the removal of arsenic from scorodite using sulfidizing annealing are presented. The reaction order with respect to the reactant and the activation energy are established from the experimental data. The rate-determining step of the sulfidizing annealing process is determined. The main reactions that occur during the sulfidizing of arsenic in scorodite are proposed on the basis of the obtained results and confirmed by thermodynamic calculations and chemical analyses. The major results of testing this technology, as applied to the refractory oxidized ores in which arsenic is mainly concentrated in scorodite, are presented. Arsenic removal from this ore is confirmed by chemical and quantitative X-ray diffraction analyses and by qualitative phase analysis. Industrial use of this technology provides safe and efficient processing of refractory gold-containing ores, where arsenic is mainly concentrated in scorodite.     

新型硫化剂制备硫代钼酸盐研究

采用新型硫化剂ＲＳ代替Ｎａ２Ｓ和ＮａＨＳ,从钨酸盐溶液中制取硫代钼酸盐。较系统地研究了硫化过程的各工艺参数,结果表明料液起始碱度８ ～１６ ｇ／Ｌ,游离Ｓ２ － 离子浓度４ ｇ／Ｌ,硫化ｐＨ 值＜ ９时,钼的萃取率可达９５ ％ 以上。     

碱性水溶液中亚砷酸硫化过程的热力学

为优化高碱条件下硫代亚砷酸萃取工艺,研究碱性水溶液中亚砷酸硫化过程热力学。基于已有的热力学数据,绘制了298K条件下As~(III)-S-H_2O系各种As~(III)离子随pH及S/As摩尔比变化的浓度曲线,分别讨论了pH和硫化剂加入量对亚砷酸硫化过程的影响以及硫化反应产物形态。结果表明,在碱性介质中,亚砷酸硫化反应在热力学上是可行的。在高碱条件下,亚砷酸硫化反应可能受抑,通过提高硫化剂用量,可强化硫化过程。     

黑龙江老柞山金矿主要载金矿物的标型特征

老柞山金矿由早、晚两期成矿作用形成,其中早期由三个成矿阶段、晚期由四个成矿阶段构成。金矿的主要载金矿物分别为：毒砂、磁黄铁矿、黄铁矿、方铅矿和闪锌矿。本文从形态、成分、含金性、热电性等各方面分别对不同世代的五种载金矿物进行研究,从而得出了老柞山床主要载金矿床的矿物学找矿标志。     

大吉山钨矿十种单矿物提纯方法

介绍了大吉山钨矿主要十种单矿物（黑钨矿、白钨矿、黄铜矿、黄铁矿、方铅矿、闪锌矿、磁黄铁矿、磁铁矿、毒砂、锡石等）的提纯方法.     

The mineralogy of pyrrhotite from Sudbury CCN and Phoenix nickel ores and its effect on flotation performance

Abstract

The non‐stoichiometric sulphide pyrrhotite (Fe_1?xS), common to many nickel ores, occurs in a variety of crystallographic forms and compositions. In order to manipulate its performance in nickel processing operations either to target the recovery or rejection or pyrrhotite, one needs an understanding of pyrrhotite mineralogy, reactivity and the effect this may have on its flotation performance. In this study, a non‐magnetic Fe₉S₁₀ pyrrhotite from Sudbury CCN in Canada and a magnetic Fe₇S₈ pyrrhotite from Phoenix in Botswana were selected to explore the relationship between mineralogy, reactivity and microflotation. Non‐magnetic Sudbury pyrrhotite was less reactive in terms of its oxygen uptake and showed the best collectorless flotation recovery. Magnetic Phoenix pyrrhotite was more reactive and showed poor collectorless flotation, which was significantly improved with the addition of xanthate and copper activation. These differences in reactivity and flotation performance are interpreted to be a result of the pyrrhotite mineralogy, the implications of which may aid in the manipulation of flotation performance.

La pyrrhotine sulfureuse non stoechiométrique (Fe_1?xS), commune à plusieurs minerais de nickel, se retrouve sous une variété de formes cristallographiques et de compositions. Afin de manipuler son rendement lors des opérations de traitement du nickel, soit afin de viser la récupération ou bien la rejection de la pyrrhotine, on a besoin de comprendre la minéralogie de la pyrrhotine, sa réactivité et leur effet sur le rendement de sa flottation. Dans cette étude, on a choisi une pyrrhotine non magnétique, Fe₉S₁₀, de Sudbury CCN au Canada et une pyrrhotine magnétique, Fe₇S₈, de Phoenix au Botswana, pour explorer la relation entre la minéralogie, la réactivité et la microflottation. La pyrrhotine non magnétique de Sudbury était moins réactive par rapport à son absorption d'oxygène et a montré la meilleure récupération par flottation sans collecteur. La pyrrhotine magnétique de Phoenix était plus réactive et a montré une mauvaise flottation sans collecteur, que l'on a améliorée significativement avec l'addition de xanthate et l'activation au cuivre. Ces différences de réactivité et de rendement de la flottation sont interprétées comme étant un résultat de la minéralogie de la pyrrhotine, dont les implications peuvent aider à manipuler le rendement de la flottation.     

Vanadium sesquisulfide and its properties

Summary A study was made of the preparation of vanadium sesquisulfide by the technique of sulfidizing metallic vanadium powder with hydrogen sulfide. The stability of vanadium sesquisulfide in various media and its oxidation resistance were investigated.Translated from Poroshkovaya Metallurgiya, No, 2 (50), pp. 6–7, February, 1967.     

Zeta potential of the surface of ultrafine sulfides and floatability of minerals

The results of experimental investigations into the zeta potential of ultrafine sulfides (chalcopyrite, tennantite, galenite, sphalerite, pyrite, and pyrrhotine), the floatability of monomineral fractions of sulfides of the floatation coarseness (–0.1 + 0.05 mm) in a mechanical flotation machine, and the floatability fine particles of sulfide (–0.044 + 0.010 mm) in the Hallimond tube are presented. The preparation procedure of ultrafine powders and sulfhydril collectors to measure the zeta potential is presented. Zeta potentials of the surface of mineral particles and insoluble forms of sulfhydril collectors are investigated in the pH range from 2.0 to 12.5 (an acidic medium was formed by using H₂SO₄ and basic one by using NaOH or Ca(OH)₂), and various values of zeta potentials are found for sulfides in the sodium hydroxide and lime medium. Zeta potentials for all sulfides are negative in the NaOH medium at pH > 9.5, they are positive (1–18 mV) in the Ca(OH)₂ medium at pH > 11, and zeta potentials for chalcopyrite are positive in the studied range \(p{H_{Ca{{\left( {OH} \right)}_2}}}\) 9.0–12.5. The values of the isoelectric point in the medium of sulfuric acid and sodium hydroxide are as follows: for chalcopyrite—pH 6.5 and 8.8, for tennantite—pH 3.0, for sphalerite—pH 5.1 and 6.4, for pyrite—pH 3.1 and 8.9, and for pyrrhotine—pH 7.0. In the lime medium, the value for tennantite and sphalerite pH 12.0, for galenite—pH 11.2, for pyrite—pH 9.5 and 11.2, and for pyrrhotine—pH 9.5 and 12.1. Measurements of zeta potentials of ultrafine sulfide particles give the opportunity to refine the interaction mechanism of sulfhydril collectors with sulfides and associate the nonselective recovery of final tailings of sulfides in the highly alkaline lime medium with the contribution of the electrostatic component during the adhesion of ultrafine sulfide particles on bubbles and their mechanical carryout into the froth product.     

Leaching of pyrrhotite with hydrochloric acid

Abstract

When nonstoichiometric pyrrhotite is leached under nonoxidizing conditions in warm aqueous solutions containing HCl, both hydrogen sulphide and elemental sulphur are formed. The amount of sulphur is proportional to the nonstoichiometry of the pyrrhotite. The leaching reaction is rapid (only seconds required to completion) but, when minimum conditions of acidity and/or temperature are not met, the sulphur coating becomes protective and the reaction ceases. When the reaction is begun rapidly, all of the acid or all of the pyrrhotite will be consumed, depending upon which is in excess. In hydrochloric acid, pentlandite dissolves more slowly than pyrrhotite but chalcopyrite is almost insoluble.

Résumé

A des températures au-dessous de 100°C quand les pyrrhotines de composition non stoichiométriques sont lixiviées par des solutions d'acide chlorhydrique en milieu non-oxydant, les produits de la réaction sont l'hydrogéne sulfuré et le soufre. La quantité de soufre produit est proportionnelle au degré de non stoichiométrie de la pyrrhotine. La réaction est rap ide (question de secondes seulement) mais au-dessous d'un minimum d'acide et de température, la couche de soufre recouvre la surface et la réaction s'arrête. Par contre, si la réaction débute rapidement elle se continuera jusqu’è l'épuisement du réactif minoritaire (HCl ou pyrrhotine). En milieu chlorhydrique la pentlandite se dissout plus lentement que la pyrrhotine, mais la chalcopyrite est très peu soluble.     

Elevated temperature fatigue crack growth in incoloy alloy 800 in sulfidizing environments

Rates of fatigue crack growth in INCOLOY alloy 800 were measured in He-SO₂ and He-H₂S environments at a frequency of 0.1 Hertz over a temperature range of 316 to 650 °C. Increasing concentrations of sulfur and increasing temperatures increased the growth rates at higher △K values. H₂S environments were more aggressive than SO₂-containing gases, probably because of the inhibiting effects of oxygen when SO₂ reacted with the alloy. At lower crack growth rates, sulfide particle formation at the crack tips caused cracks to decelerate and stop due to crack tip blunting and inhibition of crack closure. Sulfide particle formation also promoted the formation of periodic crack opening jumps. Under static loading, cracking could be produced only by a combination of prior cyclic deformation and the presence of a sulfidizing environment. The results suggest that sulfidizing environments enhanced fatigue crack growth through enrichment of sulfur ahead of the crack tip, producing a time-dependent crack growth process.     

High-cycle fatigue-life of the cast nickel base-superalloys in 738 LC and IN 939

The high cycle fatigue (HCF) properties of two cast nickel base-superalloys, IN 738 LC and IN 939, were investigated using both fracture mechanics samples and smooth specimens. The crack propagation behavior was studied in terms of linear fracture mechanics at RT and at 850 °C. In addition to the influence of temperature, the influences of frequency, mean stress, and environment (vacuum, air, sulfidizing atmosphere) were studied. At 850 °C, the fatigue thresholds were found to be higher in air than in vacuum. This could be explained by crack branching. The high scatter of fatigue crack propagation rates could be related also to this phenomenon. The S/N curves at 850 °C can be predicted treating crack growth from casting pores as the predominant failure mechanism. At RT the same method is not as successful. The reason for this may be that crack growth laws measured on long, branched cracks are not applicable to short, unbranched cracks. At RT, no significant influence of frequency on S/N-curves and fatigue crack growth rates was observed for frequencies up to 20 kHz.     

Features of reduction of high-magnesia nickel ore of the serov deposit

Parameters of reducing the roasting of high-magnesia oxide nickel ore containing, wt %, 1.2 Ni, 0.026 Co, 17.0 Fe₂O₃, 4.0 Al₂O₃, 20.2 MgO, and 46.0 SiO₂ are evaluated. The degrees of reduction and metallization upon heating the ore with the reducing agent in the range t = 800−1250°C and the sizes of metallic inclusions forming in the course of the process are determined. To separate the phases, the magnetic separation of reducing products at H = 40 and 80 kA/m is used. The best characteristics are attained upon roasting the ore with a reducing agent and a sulfidizing agent at t = 1300°C. In this case, the magnetic fraction contains 7.1% Ni, while the nonmagnetic one contains 0.18% Ni.     

A review on the methods of treating nickel-bearing pyrrhotite; with special reference to the Sudbury Area pyrrhotite

Abstract

The published methods for the recovery of values from nickeliferous pyrrhotite are summarized. For this purpose the methods are divided into two groups, (1) direct hydrometallurgical and (2) pyrometallurgical.

Résumé

L'article résume les méthods publiées pour la récupération de matériaux de prix de la pyrrhotine nickélifère. Acette fin, les méthodes sont divisées en deux groupes soit (1) hydrométallurgiques directes et (2) pyrométallurgiques.     

Processing Techniques for Difficult-to-treat Ores by Combining Chemical Metallurgy and Mineral Processing

This paper is concerned with a review of published literature on the processing of difficult-to-treat ferrous and nonferrous ores that have very fine liberation size and have constituent minerals with similar properties for which the conventional mineral processing techniques are ineffective. By altering mineralogy either pyrometallurgically or hydrometallurgically, the low cost methods of mineral processing could be applied on ores which are complex and refractory in character.

It briefly reviews methods such as magnetizing roasting and direct reduction for ferrous ores and discusses the pyrometallurgical pre-treatments on nonferrous ores, such as sulfidizing roasting, roast-flotation, segregation process and matte separation process, and hydrometallurigcal pre-treatments to extract valuable metal values by applying leach-precipitation-flotation method, and ion flotation.

Application of a combination of chemical metallurgy and mineral processing methods to solid waste materials, in particular, steel plant wastes, nonferrous slags, smelter flue dusts and anode slimes have also been briefly discussed.     

Methods of Minerals Modification by the Micro- and Nanoparticles of Gold and Platinum for the Evaluation of the Collectors Selectivity at the Flotation Processing of Noble Metals From the Fine Ingrained Ores

The paper explicates methods of the mineral surface coating by noble metals allowing to obtain samples with micro- and nanoparticles of Au and Pt, simulating natural objects. The purpose is to investigate the sorption and flotation properties of collectors. As a result we obtained the samples of pyrite, pyrrhotine, arsenopyrite, and quartz artificially enriched by micro-sized and nano-sized particles of noble metals. The coating of noble metals was carried out using the method of reducing adsorption from H₂[PtCl₆], H[AuCl₄], Na₂[PtCl₆], and Na[AuCl₄] solutions and the method of adsorption of nano-sized particles from Au and Pt sols. Depending on the conditions of the sulfides enrichment by noble metals and sizes of new formations of Au and Pt, we considered possible areas of application, methods of samples’ research, and reagents interaction with microparticles and nanoparticles of gold and platinum. A complex of research methods of reagents’ interaction with metals and flotation investigations of minerals and ores revealed the selective properties of new complexing collectors (perhydro-1,3,5-ditiazin-5-yl-methane (MTKH), sodium di(isobutyl)dithiophosphinate (DIF), 2-(ethylthio)ethylamine (ETEA)) due to their chemical interaction with gold and platinum.     

Reaction rates for sulfur fixation with iron at 1100 to 1275 K

The rates of sulfidizing iron in a simulated coal gasification atmosphere were studied. Mixtures of H₂S and CO were passed through fixed beds of coal char and prereduced iron ore, and effluent gas compositions were measured as a function of time. These mixtures ranged from 2.5 pct to 10 pct H₂S at various flow rates, with temperatures from 1100 K to 1275 K and iron ore sizes from 10 mesh down to 100 mesh. Experimental conditions were established to form a steady state reaction profile in the fixed bed. Analysis of the exit gas provided a measurement of the profile. The slope of the profile was used directly as a measure of the reactivity of the solids in the bed. The development of this experimental technique and its experimental design requirements are discussed. The observed sulfidization rate of thein situ reduced iron ore is characterized by a single rate constantm (minutes^-1), which varies primarily with temperature and particle size and is substantially independent of gas flow rate, bed configuration, and H₂S content of the incoming gas. Accordingly, the rate constant m can be applied in the design of a combined sulfur fixation, coal gasification reactor to estimate the solids retention time, and the minimum mass of iron required per cross sectional area of reactor. CRAIG B. SHUMAKER, formerly a Graduate Student in the School of Materials Engineering, Purdue University     

Quantum-Chemical Substantiation of Properties of a Bioreagent Oxidizing Nonferrous Metal Sulfides

A structural formula and quantum-chemical characteristics of the most energetically probable stable conformation of a bioreagent molecule, which is formed upon oxidizing iron(II) ions by Acidithiobacillus ferrooxidans autotrophic mesophilic iron-oxidizing bacteria in a sulfuric acid solution consisting of iron(III) ions and three acidic residues of glucuronic acid, are determined. The bioreagent oxidant is widely applied in industry for leaching metals from sulfide ores of nonferrous metals and concentrates of concentration. Quantum- chemical characteristics of the bioreagent molecule are analyzed in comparison with anhydrous iron(III) sulfate, which is also used in hydrometallurgy as an oxidant. To investigate the structure and quantum- chemical characteristics, the molecular computer simulation method, the theory of boundary molecular orbitals, and the Pearson principle are used. It is established that the most energetically probable stable conformation of the bioreagent molecule contains acidic residue of glucuronic acid with a noncyclic structure. According to the results of investigations, the bioreagent is referred to more rigid Lewis acid (the electron acceptor) than Fe₂(SO₄)₃. The bioreagent molecule is less polarized and has lower absolute electronegativity and a twofold larger volume. The theoretical substantiation of the larger persistence of primary sulfides (pyrite, pentlandite, and chalcopyrite) relative to secondary minerals (pyrrhotine, chalcosine, and covellite) is proposed based on calculated values of boundary molecular orbitals; absolute rigidity; and the electronegativity of iron, copper, and nickel sulfides. Characteristics determining the interaction efficiency (volume, heat of formation, steric energy and its components, total energy, etc.) of the bioreagent are multiply larger than for Fe₂(SO₄)₃. The larger oxidative activity of the bioreagent relative to Fe₂(SO₄)₃ can be substantiated by a higher partial charge of the iron atom and a longer bond length between the atoms, the lower energy of the lowest free molecular orbital, and increased degree of the charge transfer during the bioreagent interaction with sulfide minerals.