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.     

Effect of powerful nanosecond electromagnetic impulses on surface and flotation properties of carbonate-bearing pyrite and arsenopyrite

The effect of powerful nanosecond electromagnetic impulses (PEMI) on the surface and flotation properties of arsenopyrite and carbonate gold-bearing pyrite from the Darasunsk deposit has been studied. X-ray-phase diffractometry, X-ray photoelectronic and IR Fourier-spectroscopy, and raster electronic microscopy were employed in investigations. It was established that the alteration of the phase composition of surface depends non-linearly on terms of treatment (dry or wet) and the number of electromagnetic impulses used and has appreciable influence on oxidation and hydrophobicity of minerals, thus allowing the selective separation of pyrite from arsenopyrite by flotation in the neutral medium. __________ Translated from Fiziko-Tekhnicheskie ProblemyRazrabotki Poleznykh Iskopaemykh, No. 5, pp. 105–118, September–October, 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     

Sudden outburst of coal and gas — failure of natural coal as a solution of methane in a solid substance

Basic Conclusions  1. The methane dissolved in natural coal may participate directly in the dynamic failure of the coal during sudden outbursts. 2. The following are factors determining the participation of dissolved methane in the failure of coal during outbursts: a high natural methane content, the fracture microstructure of the coal, and its low crack resistance. 3. It can be stated that it is precisely the dissolved methane that predetermines the formation of "mad flour." The author expresses gratitude to S. V. Kuznetsov, V. A. Bobin, I. V. Zverev, V. A. Trofimov, and M. O. Dolgov for their discussion of the study. Institute of Problems of the Complex Exploitation of Mineral Resources, Russian Academy of Sciences, Moscow. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 18–28, November–December, 1997. The study was performed with financial support from the Russian Fund for Fundamental Research (Project No. 96-05-65884).     

Interaction of Internal Structure,Chemistry, and Processing Characteristics of Pyrite from the Gaisk Deposit

Four mineralogical-processing modifications of the Gaisk deposit pyrite are distinguished; they differ in forms of appearance and content of gold, arsenic, silver, and zinc. The processing expediency is substantiated for separation of the gold-richest (more than 9 g/t) pyrite modification from the bulk by a gravitation-flotation scheme after preliminary grinding up to −0.074 mm in size, using the arsenic-selective reagent. In this case, it is theoretically possible that pyrite-associated gold extraction reaches 85 %. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 90–98, May–June, 2005.     

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     

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.     

Two-step oxidation of a refractory gold-bearing sulfidic concentrate and the effect of organic nutrients on its biooxidation

Methods for improving the treatment efficiency of a refractory gold-bearing sulfidic concentrate are proposed. These methods consist of the oxidation of the concentrate during a two-step process, which includes a high temperature ferric leaching step and a subsequent biooxidation step, and the use of organic nutrients during the biooxidation step. The concentrate contained 34.7% pyrite and 7.9% arsenopyrite. The biooxidation of the concentrate (for a one-step process) was conducted at 45 °C in two bioreactors that were connected in series under continuous conditions. The pyrite and arsenopyrite oxidation levels after 240 h were 60.2% and 92.0%, and the gold recovery level by carbon-in-pulp cyanidation was 65.7%. The two-step process included the leaching of the concentrate by a biologically generated Fe³⁺-containing solution and the subsequent biooxidation of the leach residue. In this case, the pyrite and arsenopyrite oxidation levels after 240 h of biooxidation were 65.7% and 94.1%, and the gold recovery level was 71.7%.The effect of an organic nutrient (yeast extract) on biooxidation during the two-step process was studied. The pyrite and arsenopyrite oxidation levels after 240 h of biooxidation under mixotrophic conditions were 73.5% and 95.1%, and the gold recovery level was 77.9%. The effect of the organic nutrient on the microbial population was determined. Sulfobacillus thermosulfidooxidans and Acidithiobacillus caldus were the predominant microorganisms studied under both autotrophic and mixotrophic conditions. Archaeon Acidiplasma sp. MBA-1 was a minor component of the microbial community under autotrophic conditions but was one of the predominant microorganisms studied under mixotrophic conditions. These results suggest that the organic nutrient changed the composition and increased the activity of the microbial population.Thus, a two-step process with organic nutrients added during biooxidation may be considered as an effective strategy for treating refractory pyrite–arsenopyrite concentrates.     

The selective flotation of arsenopyrite from pyrite

Flotation tests were conducted to compare the arsenopyrite depressing effect of MAA with pH control, potassium permanganate and pre-aeration. The recovery and selectivity were optimised by varying the collector and depressant concentration, pH and the effect of copper sulphate addition. It was found that with MAA, depression of arsenopyrite was possible however, the recovery of pyrite was also adversely affected. To achieve the best separation, the pulp conditions were a pH of 8, 2.14 × 10⁻³ mol/l sodium ethyl xanthate and 250 mg/l of MAA depressant. These conditions resulted in an overall arsenopyrite recovery of 25.5% and a pyrite recovery of 62.1%, a decrease in recovery of 63.0% and 7.5%, respectively.     

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.     

Refinement of methods of beneficiation of finely disperse minerals

Conclusions  The prospect of switch-over of the industry to processing lean materials raises the problem of beneficiation of finely disperse placers of noble metals, the profitability of realization of which lies in raising the efficiency of separation processes by reducing frictional forces in the course of implementation of the technological processes and by employing modern technologies for beneficiation. The engineering—technological solutions worked out are distinguished by ecological safety during implementation of the beneficiation processes. The proposed schemes of beneficiation and primary processing of finely disperse minerals may be used:

砷的赋存状态对云南某银铅锌多金属矿选矿的影响北大核心

砷是云南某银铅锌多金属矿中的有害元素。通过光学显微镜鉴定以及矿物自动分析仪AMICS等现代先进仪器,快速并准确查明了砷的赋存状态及其对选矿的影响。研究表明:该矿石中砷的品位为0.53%,砷主要分布在毒砂中,其次分布在黄铁矿中,少量分布在雄黄和细硫砷铅矿中。但是,导致银铅精矿砷超标的主要因素是雄黄和细硫砷铅矿,其次为毒砂。要想进一步降低银铅精矿中的砷,需强化对雄黄和毒砂的抑制;细硫砷铅矿与方铅矿关系密切且化学性质相近,二者很难有效分离,因此银铅精矿中砷含量很难降到0.77%以下。导致硫精矿砷高的主要因素是毒砂和含砷黄铁矿,即使黄铁矿与毒砂有效分离,硫精矿中砷含量很难降到0.22%以下。对于锌精矿来说,闪锌矿与毒砂、黄铁矿相对好分离,因此砷易脱除。研究结果为云南地区含砷银铅锌多金属矿床的选矿降砷工艺提供了理论依据。     

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.     

Analysis of a borehole driving by a pneumatic puncher

Results are presented for experimental investigation of borehole formation in soils by a pneumatic puncher which make it possible to increase borehole diameters and movement rates. The possiblity is established of determining the energy content for driving according to dynamic densimeter readings. Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 95–100, May–June, 2000.     

Use of technogenic and natural solutions in hydrometallurgical operations

Conclusions  The results obtained here demonstrate the promise of using technogenic and concentrated condensates of hightemperature heat carriers to perform leaching as part of the processing of copper-nickel ores. The productive solutions that were obtained have high contents of the useful components (grams and tens of grams per liter) and could be converted to the desired end products by proven methods [12]. The following problems should be addressed first in future research in this area:

Geomechanical conditions for quasi-resonances in geomaterials and block media

Conclusions  Based on voluminous information about relations between the dimensions of the central zones of crustal earthquakes and various energy classes of underground explosions, as well as mine shocks and man-induced tremors, therefore, the hypothesis that we had previously advanced relative to the quasi-resonant mechanism of their manifestation is confirmed. Here, the geomechanical conditions for the development of quasi-resonances associated with the inducement of pendulum waves are characterized by the dimensionless energy criterion k:

Evaluating the residual life of salt pillars

Conclusions Thus, the completed studies have made it possible to develop a technology and methodology, based on the compensation method, for measuring the load on the edges of inter-chamber pillars. An experimental-theoretical method has also been proposed for estimating the residual life of such pillars in excavated sections of potassium mines. The results of full-scale measurements established that the edge regions of interchamber pillars located near the boundary of a cave-in (region of chamber 103 in our investigation) are in the supercritical state. For a subsidence rate of 1.5 mm/day at the surface, the residual life of such pillars is estimated to be 7–8 months. The zone loaded by bearing pressure from the caved-in rock is shifted toward the interior of the goal (regiona of chamber 120). The load factor of the pillars exceeds the allowable value [C]=0.4 specified by standards for “rigid” interchamber pillars in the mines of the Verknekamsk Potassium Salt Deposit, which accounts for their “compliant” regime of deformation. Thus, to reduce the strains of the water-protective stratum and prevent water above the deposit from entering the mine, the region of chamber 120 must be filled. Mining Institute, Ural Branch of the Russian Academy of Sciences (Perm). Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 18–25, January–February, 1998. The theoretical part of this investigation was completed with financial support from the Russian Fund for Basic Research, Grant No. 96-05-64849.     

Determination of coal loss and impoverishment in the nonexplosive mining of deposits with a complex structure

Conclusions  

New technologies of mineral mining

The results are examined for the investigations performed at the Institute of Mining of the Siberian Branch of the Russian Academy of Sciences in the field of new economically profitable technologies of exploitation of coal and oil deposits. Industrial test data are presented. Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 63–74, March–April, 2000.     

青海省五龙沟金矿原矿工艺矿物学研究

青海省五龙沟金矿原矿石金品位为2.32g/t,品位较低,选矿厂生产中,金的浮选回收率仅为75%左右。为了明确该原矿矿石的工艺矿物学特性,有效提升选矿厂浮选回收率等选矿技术指标,进一步实现该矿产资源的综合开发利用,通过采用原子吸收分光光度计、电感耦合等离子体发射光谱仪、偏光显微镜、扫描电镜等仪器,对选矿厂堆场原矿矿石开展了工艺矿物学研究,从而查明了该矿石各元素含量、矿物组成、矿石中金及其载体矿物的嵌布粒度和赋存状态。结果表明,该矿石中有害元素砷和碳含量相对较高;原矿中贵金属矿物主要为自然金,金属矿物主要为黄铁矿和毒砂,其次为赤、褐铁矿、臭葱石等,脉石矿物主要为大量的石英和绢云母,其次为碳酸盐矿物、绿泥石、方解石等;矿石中主要的载金矿物为黄铁矿、毒砂和臭葱石,其中黄铁矿嵌布粒度以中粗粒为主,黄铁矿-0.64+0.04mm粒级占86.95%,毒砂嵌布粒度以中、细粒为主,-0.160+0.01mm粒级占90.09%。矿石中金的粒度极细,可见金的粒度绝大多数在10μm以下,小于0.02mm的金粒占86%以上。该原矿矿石属于微细粒-超微细粒含砷、碳的极难选冶金矿石。