Kinetics of calcium minerals flotation from Scheelite-carbonate ores

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.     

高效射流浮选机在赤褐铁矿反浮选生产中的应用

用高效射流浮选机反浮选强磁铁精矿,强磁精矿含铁42.5%,以赤褐铁矿为主,硅酸铁和碳酸铁的含量高,属难选铁矿物。选用高效射流浮选机作为浮选设备,用一粗一精一扫反浮选工艺流程,获得反浮选铁精矿品位53.5%,含SiO24.95%,铁回收率73.5%。该反浮选流程工艺简单,适应性强。     

Effects of aluminosilicate minerals on copper-molybdenum flotation from Sarcheshmeh porphyry ores

The presence of aluminosilicate minerals adversely affects the floatability of copper during processing of Sarcheshmeh porphyry ores. In this work, ores containing different types and quantities of aluminosilicate minerals, as well as copper sulfides (i.e., chalcopyrite and chalcocite), were examined in the laboratory to determine how aluminosilicate minerals affect the floatability of copper and to find ways to decrease their unwanted effects. It was shown that ore types that contain muscovite and vermiculite have the greatest effect on the floatability of copper sulfides. To overcome this problem, two reagent strategies were used: (a) dextrin at 100, 200, and 600 g/ton and (b) a mixture of dextrin, sodium silicate, and sodium hexametaphosphate (20%, 40%, and 40% by weight, respectively) at 200 and 300 g/ton. The reagent mixture (case b) at a dosage of 200 g/ton improved the copper recovery and decreased the grade and the recovery of Al₂O₃ and SiO₂ in the flotation concentrate. As an alternative solution, flotation at reduced pulp density (24%) improved the grade and the recovery of copper and molybdenum and decreased the grade and recovery of Al₂O₃ and SiO₂ in comparison to the currently used pulp density (29%) in the Sarcheshmeh flotation plant.     

Fundamental aspects of hematite flotation using the bacterial strain Rhodococcus ruber as bioreagent

Previous research showed the effectiveness of bacterial strains as flotation reagents on Hematite beneficiation. The aim of this work is to study and evaluate Rhodococcus ruber as a biocollector. The sample was conditioned with the biomass suspension by stirring under specific conditions as particle size, biomass concentration, pH solution and conditioning time. The results showed a change in hematite zeta potential profile after interaction with R. ruber, and its adhesion onto the mineral surface was higher at pH 3 and at concentration of 0.60 g/L (10⁹ cells/mL). Flotation studies were carried out in a 0.23 L modified Partridge–Smith cell flotation, and the highest floatability (84%) was achieved at size fraction −53 μm +38 μm under the conditions mentioned before. Complementary floatability studies were performed using the conventional frother Flotanol D24 combined with the R. ruber biomass, finding interesting results for the bigger particle size range. Thus, this research aims to evaluate the efficiency of bioflotation of minerals, particularly hematite, and the potential use of R. ruber as biocollector, projecting its future application in mineral flotation industry.     

The effect of non-sulphide gangue minerals on the flotation of sulphide minerals from Carlin-type gold ores

Flotation pre-concentration of sulphide and gold values from certain Carlin-type deposits characterised as double-refractory gold ores is quite challenging. Numerous studies conducted on these ores in many laboratories globally (including the present study) under a variety of chemical and physical conditions have merely confirmed low recovery (and poor concentrate grades) for sulphide minerals and gold, and poor separation between sulphide minerals and carbonaceous matter, even when the valuable minerals are adequately liberated. None of the traditional reasons based on liberation or the choice of chemical and physical conditions and separation strategies could provide satisfactory explanation for the observed poor separation.In this study, the focus was on the role of non-sulphide gangue (NSG) minerals. It was hypothesised that specific NSG minerals have a detrimental effect on flotation recovery of gold bearing minerals and their separation selectivity. In order to test this hypothesis and delineate the effect of the various gangue minerals, a new approach was taken. This involved first isolating the various mineral components of a double-refractory gold ore from one of the Carlin-type deposits using a gravity separation technique. Then flotation experiments were performed using a mixture design on various mixtures of these isolated components under controlled conditions. The results of these mixture experiments supported the hypothesis and demonstrated, for the first time for these types of ores, that even small amounts of NSG minerals, especially carbonaceous matter and clays, had a large adverse effect on the flotation of sulphides and selectivity of separation. While it is tempting to attribute the observed effects solely to slime coating, there is no basis to do so at this stage; it is more reasonable to propose that multiple contributions exist. The results of this study provide the much-needed context and direction for further fundamental studies and for developing processing strategies.     

Increase in contrast of wettability of the sulfide minerals in Copper-Zinc ores during flotation and flocculation

Consideration is given to the influence exerted by styrene-butadiene copolymer on wettability of the surface of pyrite, sphalerite, and chalcopyrite as well as on flocculation and floatability of mineral slimes. It is established how pH and styrene-butadiene copolymer combined with xanthate affect the change in hydrophoby of the sulfides in question and the processes of flocculation and flotation. The conditions are determined for the improvement in contrast of properties of separated minerals.Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 95–100 May–June, 2004.     

Flocculation/flotation of hematite fines with anionic temperature-responsive polymer acting as a selective flocculant and collector

A novel approach to the recovery of valuable fines is the use of temperature-responsive polymers such as poly (N-isopropyl acrylamide) (PNIPAM). These polymers act as dual-function flocculants and collectors to form hydrophobic aggregates improving particle–bubble collision and attachment. The aim of this study is to investigate the flotation performance of anionic PNIPAM for an iron ore sample containing fines compared to sodium oleate, an industrial collector for hematite. PNIPAM conditioned at room temperature (25 °C, below the lower critical solution temperature (LCST)) and floated at 50 °C (above the LCST) was found to provide improved hematite grade and recoveries for particles above 20 μm, compared to sodium oleate. This was attributed to the increased selectivity and hydrophobicity of PNIPAM. Turbidity testing confirmed the flocculation of fines with PNIPAM, which deslimes the surface of the coarser particles. Below 20 μm, the hematite fines were almost completely recovered with PNIPAM. However, this recovery was not selective, attributed to the entrapment of gangue in the hydrophobic aggregates. Furthermore, conditioning of the polymer above the LCST resulted in significant losses in grade and selectivity, as the polymer self-aggregates hydrophobically and precipitates unselectively onto the closest surface.     

The response of sulphide and gangue minerals in selected Merensky ores to increased depressant dosages

Depressants are added to flotation circuits to reduce naturally floatable gangue (NFG) present in ores, but under certain conditions have been shown to affect sulphide mineral recovery, particularly guar reducing the recovery of pyrrhotite. Copper sulphate is added to increase sulphide mineral recovery, but may also activate gangue particularly in the presence of dithiophosphate. This has also been shown to vary with ore type. Previous work has shown the usefulness of analysing reagents holistically, decoupling pulp and froth effects and assessing material recovered by true flotation and that recovered by entrainment separately. This work assesses the effect of copper activation on different ores and the ability of two classes of depressants, guar gum (guar) and carboxymethylcellulose (CMC) to reduce this effect and shows that by a depressant dosage of 300 g/t almost all the NFG had been removed from the concentrate. It also evaluates the effect of depressants on the sulphide minerals and shows that pyrrhotite was most affected.     

分步浮选工艺处理含碳酸盐赤铁矿石

介绍了含碳酸盐赤铁矿石的性质、结构及粒度组成,探讨引起铁矿物分离困难的原因,进而研发出分步浮选,并在东烧厂进行工业试验,实验结果证明该工艺可行.     

Influence of sodium thiosulphate on oxidation of sulphide minerals during selective flotation of copper-nickel ores

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.     

Evaluation of alternative reagent schemes for the flotation of platinum group minerals from various ores

In the past several years, research work has been carried out on a number of different ores containing platinum group elements (PGE), with the objective of developing alternative reagent schemes that would improve PGM recovery and concentrate grade in the operating plants.It has been demonstrated that the floatability of PGE-bearing minerals largely depends on the type of deposit and how the deposit was formed. The uniqueness of PGE deposits and their formation dictates the development of the treatment process and, in particular, the reagent schemes for different ore types.In this study, a number of different new reagents, including collectors, depressants and modifiers, were identified as highly effective for the treatment of different ores containing PGE minerals. Results from bench scale research work using new reagents are presented in this paper. The type of ores and the effect on flotation are discussed in detail.     

Lower temperature flotation of carbonate-fluorite ores

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.     

响应曲面法优化赤铁矿絮凝体浮选行为研究

采用淀粉为絮凝剂对平均粒径为8 μm的赤铁矿纯矿物进行絮凝,形成平均粒径36.17 μm、絮凝体密度2.89g/cm3、絮凝体孔隙率49.12％、分形维数为1.90的絮凝体.根据Box-Behnken实验设计原理,采用响应曲面法建立pH值、捕收剂油酸钠用量、搅拌转速及三者之间交互作用对赤铁矿絮凝体回收率影响的多元回归方程,对实验结果进行了 ANOVA分析.在矿浆pH为7.76,油酸钠用量为132.22 mg/L,搅拌转速为1844 r/min,此条件下模型预测絮凝体回收率达到93.65％.通过赤铁矿浮选条件探究,得出其对絮凝体浮选的作用规律,为指导实践生产应用提供理论支撑.     

Cationic flotation of nonsulfide minerals

From the analysis of information on flotation of quartz, barite, hematite and diamond spar using cationic reagents (amines), the authors show deficiency of thermodynamic approach to explain flotation results by one type of adsorption due to ion–electrostatic mechanism. The discussion offers hypothesis that says that at low pH collecting ability of a reagent is connected with hydrophobic attachment of the reagent ions in adsorption layer. In alkaline range of pH, the collecting ability is conditioned by formation and precipitation of ionomolecular associates in the adsorption layer of a mineral. These types of adsorption attach particle surface which is preliminarily made hydrophobic by ion–electrostatic mechanism. These adsorption types are active at bubble–liquid interface and can go to this interface upon rupture of water film between a particle and a bubble. According to the suggested hypothesis, liquid tension in the film becomes nonuniform and a surface force arises and expels kinematic constraint for particle–bubble attachment. The analytical review of the collected test data on cationic reagents proves the suggested hypothesis. The causes of breakdown of correlation between surface pressure and collecting ability for initial conditions of flotation are explained.     

基于粒度对混合稀土纯矿物浮选过程影响分析

以包头白云鄂博混合稀土纯矿物为研究对象,通过对不同粒度混合稀土纯矿物浮选及其动力学行为探索,研究了矿物粒度对浮选过程的影响。结果表明:混合稀土精矿的动力学与一级动力学模型的匹配度最高,同时不同粒径的颗粒对矿物浮选行为产生较大的影响。在混合稀土纯矿物分批刮泡粗选中,-40+10μm颗粒的浮选速率常数及REO的最大回收率均大于-10μm和+40μm颗粒;而对于混合稀土纯矿物一次粗选、三次精选浮选流程来说,随着精选次数的增加,可浮性优的颗粒(-40+10μm粒级)在浮选精矿中的富集程度逐渐增大,并且在第3次精选精矿中其比例远高于可浮性差的颗粒(+40μm粒级和-10μm粒级)。因此,对于白云鄂博稀土纯矿物浮选来说,-40+10μm颗粒可浮选性优于+40μm和-10μm颗粒。通过对白云鄂博稀土混合矿粒度在浮选过程的研究,为其浮选工艺提供了有力的理论依据。     

赤铁矿石磁-重-反浮选联合工艺的研究

介绍了舞阳矿业公司赤铁矿石的性质,分析了其工艺矿物学特点,根据试验结果选定了磁-重-反浮选联合工艺流程,并通过生产实践加以完善.     

Organic modifiers for flotation of copper-zinc-pyrite ores

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.