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1.
The objective of this work was to determine the effect of Leptospirillum ferrooxidans on the floatability of chalcopyrite, sphalerite, and pyrrhotite by using xanthate as a collector. The tests were carried out in the absence and presence of bacteria in relation to the type of ore and contact time with bacteria. The results indicate that the chalcopyrite flotation rate significantly increased in the presence of L. ferrooxidans due to the formation of hydrophobic species. The bacteria function as a weak depressant for pyrrhotite after a conditioning time ?60 min. The behaviour of sphalerite remains without changes due to its low susceptibility to oxidation. It was concluded that L. ferrooxidans brings about superficial changes mainly due to the oxidation of minerals.  相似文献   

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The studies of sulphur distribution in oxidation products of pyrrhotite and chalcopyrite being components of Cu-Ni ores showed that the elementary sulphur — sulphoxide ion ratio on the mineral surface and in the liquid phase of mineral suspensions changes in the presence of sodium thiosulphate. Sodium thiosulphate exhibits properties of a reducing agent and prevents formation of hydrophobic elementary sulphur on pyrrhotite surface due to oxygen absorption and oxidation of thiosulphate-ions to sulphates. The decrease in pyrrhotite floatability is observed, and more favorable conditions are provided for selective flotation of chalcopyrite on copper-nickel ore processing. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 4, pp. 89–94, July–August, 2006.  相似文献   

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This paper examines published and new experimental evidence on the effect of the grinding environment on fine (?10 μm) value mineral recovery in flotation. Reasons for increases in fine value mineral recovery from ores with fully electrochemically inert grinding media are discussed in relation to reduced surface contamination by iron hydroxide emanating from the grinding media. The application of stirred milling technology, which allows the use of fully inert grinding media, to primary grinding applications may lead to increased fine value mineral recovery in flotation rougher applications. It is suggested that the effect of the grinding media, which is important for fine particles and progressively becomes more important as the grind size becomes finer, is principally due to the abrasion mechanism of the minerals with the grinding media in the production of fine particles. Opportunities for research and industry application are discussed.  相似文献   

4.
The effect of particle-bed breakage mechanisms on the liberation properties of ores remains unclear. Surprisingly few studies have been published in this area and limitations in liberation measurement techniques previously used have prevented definitive conclusions from being reached regarding whether particle-bed breakage enhances the liberation properties of mineral ores relative to conventional grinding mechanisms. In this study, two sulphide ores of differing textures were comminuted to various size distributions using impact and particle-bed breakage mechanisms in a hammer mill and a piston–die compression unit respectively. The liberation properties of the various discharge samples were then characterised using a mineral liberation analyser – a mineralogical characterisation system based on automated scanning electron microscopy. It was found that the size-by-size liberation properties of both valuable and gangue mineral phases were independent of both the method used to comminute the samples, as well as the particle size distribution of the final products. These effects are discussed in terms of how they may be exploited in liberation modelling and characterising comminution circuit performance.  相似文献   

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Lower temperature flotation of carbonate-fluorite ores   总被引:1,自引:0,他引:1  
The authors provide insight into the problem of selective flotation of fluorite from carbonate-fluorite ores. It is found that oxyhydrate collectors used in combination with sodium fluoride provide rather high level of selectivity in fluoride flotation from poor high-carbonate ores and make it possible to eliminate high-temperature pulp treatment with acceptable reduction in the flotation temperature to 15°C and below.  相似文献   

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《Minerals Engineering》2007,20(3):264-272
The Rosh Pinah orebody is a complex lead–zinc sulphide system with pyrite gangue and minor amounts of copper. Laboratory scale milling and flotation testing of ore samples taken from this operation was performed. Different grinding media and conditions were used, including ceramic, stainless steel and steel. Flotation tests used a sequential recovery protocol for selective flotation of first the lead and thereafter the zinc. The presence of species of oxidation products on the ore after milling was probed using ethylene diamine tetra-acetic acid (EDTA) leaching. The test data show that, for comparable grinds and reagent dosages, the choice of grinding media has a marked effect on the paymetals recoveries and the selectivity. The ceramic mill produced the highest recoveries but the poorest selectivity. The steel mill produced the converse result. It is proposed that this is because the ceramic mill produces an oxidizing environment, allowing sphalerite activation by copper ions, whilst the steel mill produces a reducing environment, preventing this activation.  相似文献   

10.
采用旋流-静态微泡浮选柱用于白钨矿粗选的半工业试验,主要开展了处理量试验和药剂用量试验.72 h连选试验结果表明,采用一次粗选、一次精选闭路流程,利用旋流-静态微泡浮选柱可得到9.76%的白钨粗精矿,尾矿品位0.10%,且对回收率影响不大.  相似文献   

11.
Institute of Organic Chemistry and Polytechnic Institute, Siberian Branch, Russian Academy of Sciences, Irkutsk. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 5, pp. 87–91, September–October, 1993.  相似文献   

12.
Mixtures of collectors have been widely used for many years in sulphide flotation, and a range of performance benefits have been reported for many different systems. The combinations of collector types have varied, as have the ratios that have been used. Synergistic effects have been obtained (greater than the sum of the parts) and in some cases the mechanisms of this improved behaviour have been identified. These benefits have been attributed to increased carrying capacity of the froth phase, faster kinetics, and more successful recovery of middling or coarse particles. It is the interaction between the various components of the mixed collector system, rather than the individual main effects, that dominate the performance benefits. The process benefits include increased paymetal recoveries and grades – as well as increased rates of recovery whilst using lower dosages of reagents. Various mechanisms have been reported and are discussed. These have been shown to affect different composition/liberation classes and sizes of mineral particles. In recent years, automated quantitative mineralogy and surface analysis technology such as ToF-SIMS have enabled the development of better information, to establish what aspect of the process has been affected. This has been successful mostly for use in a diagnostic capacity. Candidate selection for the mixed collector suite is presently based on experience and contextual knowledge. Predictive properties from these systems are a desirable future goal. Currently optimum combinations are preferably identified experimentally at laboratory scale prior to any plant trial. It is recommended that such laboratory work be performed using a factorial design with replicates and quality controls, such as may be delivered from High-Confidence Flotation Testing. The purpose of this paper is to summarise and review current theory and practice in the usage of mixtures of collectors in sulphide flotation – both in the application and in research in order to develop insights and guidelines to develop a methodology for use in a predictive capacity. A case study demonstrating this approach will be published at a later date.  相似文献   

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Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 75–79, January–February, 1995.  相似文献   

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Kinetics of calcium minerals flotation from Scheelite-carbonate ores   总被引:1,自引:0,他引:1  
The laboratory and commercial tests of ore specimens with different content of tungstic oxide and calcite have been conducted, and basic patterns of flotation have been established. Based on the results of analytical and practical studies, the actual processing plant??s operating practice and processing flow sheet have been upgraded.  相似文献   

18.
Platinum concentrator plants experience significant losses in their overall Platinum Group Elements (PGE) recoveries due to the inefficiencies of their secondary grinding circuits. This study involves an investigation of selective grinding of the platinum-bearing silicate particles present in UG-2 platinum ores found in the Bushveld Igneous Complex (BIC).Batch-scale laboratory test work was done to investigate the effect of a secondary milling circuit configuration, using a hydrocyclone underflow sample from a UG-2 concentrator plant as feed material. The envisaged secondary milling circuit consists of a conventional hydrocyclone to de-slime the feed followed by density separation with a spiral concentrator to separate the ore into lights (silicates-rich) and heavies (chromite-rich) fractions, followed by separate milling of the two fractions in parallel ball mills, and combined rougher flotation. A full-scale spiral was run in batch mode, followed by separate milling of samples in a 200 mm diameter mill and combined flotation in a 4.2 l cell. The milling energy inputs were re-distributed between the lights and heavies mills to determine the effect on the platinum mineral rougher flotation recovery and the Cr entrainment.The most promising results were found with 88% of the energy input to the lights mill and 12% to the heavies mill. The results indicated that under batch conditions, the secondary rougher flotation recovery (69% 4E) was similar to the conventional mill-float circuit (70%) however the Cr entrainment was significantly reduced by approximately 40% (2.3–1.4% Cr).This test work has confirmed the benefit of separate milling in the secondary milling circuit for a UG-2 ore. Spiral concentrators have shown potential as an effective density separating device to produce a silicate-rich and chromite-rich fraction for milling; further test work will be conducted to confirm its viability on an industrial scale.  相似文献   

19.
调整剂在菱镁矿石英反浮选分离中的作用研究   总被引:2,自引:0,他引:2  
针对反浮选去除菱镁矿石中石英分离时效率较低的问题,以含钙的盐类化合物KD-1为调整剂,分别以实际矿石和单矿物为试样,研究了KD-1对分离过程的影响.结果表明,醚胺为捕收剂反浮选时添加KD-1,可明显改善分离效果.在精矿中SiO2含量不变的条件下,添加1500g/t KD-1,可使捕收剂用量下降58%,精矿产率提高4.24%.机理研究表明,KD-1对石英与菱镁矿浮选分离的作用,主要是使泡沫变得均匀,且流动性增强,表面积增加.  相似文献   

20.
A literature review has shown that the chemical effects of grinding media on the flotation of real ores, especially those containing pyrite, are still not understood adequately. Many studies have been conducted on isolated minerals or in solutions only, and transport phenomena in the froth phase have generally been ignored in studies on galvanic interactions. A complex ore containing galena, sphalerite, chalcopyrite and significant quantities of magnetite, pyrrhotite and pyrite was used in batch flotation tests to study this problem. Metallic iron powder was added in different quantities to a ceramic ball mill in order to simulate the use of mild steel grinding media in flotation tests aimed at selectively floating chalcopyrite.An oxygen-saturated pulp milled in the presence of iron yielded the best recovery of chalcopyrite and copper-lead selectivity. Milling under a nitrogen atmosphere in the absence of metallic iron resulted in poor copper-lead selectivity. The galvanic interaction caused by the presence of iron yielded a stable, well-drained froth with low ratios of solids/water recovery and larger bubbles in the froth. However, milling in the absence of iron caused an extremely brittle froth with very fine bu bubbles, high recoveries of low grades of sulphur. In contrast with the improvement in the copper recovery and copper-lead selectivity obtained when the pulp was pre-aerated after milling in the presence of iron, no significant increase in the copper grade was observed after extensive pre-aeration when milling occurred in the absence of iron. The unsatisfactory flotation results in the absence of iron could be explained by the enhanced floatability of iron-bearing gangue minerals, which rupture films and suppress froth stability owing to bubble-overloading.  相似文献   

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