石灰环境中硫代硫酸钠对黄铁矿抑制机理研究

通过单矿物浮选试验、动电位测定、红外光谱测定和XPS测定,考察石灰环境中络合剂对黄铜矿和黄铁矿可浮性的影响,研究络合剂在石灰环境中与黄铁矿间的抑制作用机理。单矿物浮选试验结果表明,较高的丁基黄药浓度下,可以使用硫代硫酸钠与石灰配合使用从而达到铜硫有效分离的目的。动电位测定结果表明,石灰调浆时黄铁矿表面动电位大幅度正移,硫代硫酸钠的加入又使动电位明显负移,说明在石灰环境中添加硫代硫酸钠时,硫代硫酸钠在黄铁矿表面发生了吸附。红外光谱分析表明,黄铁矿单独与硫代硫酸钠作用时,SO₄^2-和S₂O₃^2-的特征吸收峰出现,表明硫代硫酸钠在黄铁矿表面产生了吸附。然而在石灰环境中,只出现SO₄^2-的特征吸收峰,硫代硫酸钠的作用不明显。XPS检测结果表明,黄铁矿经过硫代硫酸钠处理后,表面Fe、S、O的化学环境发生了改变;黄铁矿经过石灰处理后,表面Fe、S的化学环境发生了改变;黄铁矿经过石灰+硫代硫酸钠处理后,Fe、O、S的化学环境发生了改变。通过上述试验及检测分析可知,硫代硫酸钠在石灰环境中与黄铁矿表面发生了吸附及反应,可能是S₂O₃^2-与Fe³⁺或Fe²⁺发生络合反应生成络合物。     

富含可溶性盐高硫铅锌矿无碱浮选工艺研究

云南某铅锌矿有些高硫铅锌矿石中硫酸锌、硫酸亚铁等可溶性盐类含量高,使浮选矿浆中存在大量的Zn2+,Fe2+等金属离子。按常规浮选工艺用石灰抑制黄铁矿时,这些金属离子与石灰作用产生大量的氢氧化物沉淀,对铅锌矿物有很强的抑制作用,造成铅锌矿物不能有效分选。为减少可溶性盐对铅锌浮选的影响,采用在矿浆自然酸碱性（酸性）下浮选铅锌矿物的无碱工艺,选铅时以硫酸锌和亚硫酸钠作抑制剂,以苯胺黑药和丁铵黑药作铅捕收剂,选锌时以水玻璃、亚硫酸钠、羧甲纤维素作调整剂,以PN405作锌捕收剂,获得了含铅59.57%,铅回收率为75.14%的铅精矿和含锌53.93%,锌回收率为93.70%的锌精矿。     

Cu2+活化黄铁矿与黄铜矿的浮选分离

在研究丁黄药体系中黄铜矿、黄铁矿单矿物的天然可浮性,石灰（调节矿浆pH）、亚硫酸氢钠、铜离子对黄铜矿、黄铁矿可浮性的影响,柠檬酸对被Cu²⁺活化的黄铁矿、黄铜矿可浮性的影响,柠檬酸-亚硫酸氢钠-石灰组合抑制剂对被Cu²⁺活化的黄铁矿、黄铜矿可浮性的影响的基础上,采用柠檬酸-亚硫酸氢钠-石灰组合抑制剂对被Cu²⁺活化的黄铁矿-黄铜矿人工混合矿进行浮选分离,得到了铜品位和铜回收率分别为24.12%和88.48%的铜精矿,及硫品位和硫回收率分别为49.69%和72.51%的硫精矿,表明该组合抑制剂对被Cu²⁺活化的黄铁矿具有良好的选择性抑制作用。     

含钒石煤选择性脱泥富集钒的试验研究

含钒石煤,经焙烧脱碳后,在磨矿过程中会产生大量的原生及次生矿泥,这些矿泥的存在,在浮选过程中会消耗大量浮选药剂,增加选矿成本,并降低选矿指标。针对湖北通山含钒石煤进行了选择性脱泥富集钒的试验研究,在用20%H2SO4溶液调节p H为9.0,六偏磷酸钠的用量为1.0 kg/t条件下,得到了V2O5的品位为1.07%,产率为10.91%的矿泥产品。     

Impact of gypsum supersaturated solution on surface properties of silica and sphalerite minerals

In some sulphide mineral flotation operations, the process water contains high concentrations of calcium and sulphate ions that exceed the solubility limit of gypsum. It has been speculated that the gypsum supersaturated process water would lead to precipitation of gypsum which could coat on mineral surfaces by either nucleation or coagulation, resulting in reduced flotation recovery and selectivity. In this study, a laboratory prepared gypsum supersaturated solution is used to represent the gypsum supersaturated process water, the effect of gypsum supersaturated solution on the surface properties of silica and sphalerite minerals was investigated using zeta potential distribution measurements, scanning electron microscope (SEM), X-ray photon spectroscopy (XPS), Auger electron spectroscopy (AES), and quartz crystal microbalance with dissipation (QCM-D). Our results show that silica and sphalerite minerals carry identical surface charge (−10 mV of zeta potential) in the gypsum supersaturated solution at pH 10 although they are charged differently in simple electrolyte solution at the same pH. Needle shape gypsum precipitates are found in both silica and sphalerite minerals systems conditioned with gypsum supersaturated solution. The gypsum precipitates do not grow on the minerals surfaces but form in the bulk gypsum supersaturated solution. The heterocoagulation between the examined minerals and gypsum particles is insignificant in the gypsum supersaturated solution. It is the high calcium concentration in the gypsum supersaturated solution that has significant effect on the surface properties of silica and sphalerite minerals. The zeta potentials of silica and sphalerite in a 800 ppm calcium solution (similar to the calcium concentration in the gypsum supersaturated solution) are similar to those measured in the gypsum supersaturated solutions. Both silica and sphalerite minerals surfaces are indiscriminately coated with calcium. The surface coating of calcium results in the identical surfaces between silica and sphalerite minerals, and ultimately causes problems for the flotation separation of silica and sphalerite.     

矿浆电位对铜钼浮选分离的影响及机理分析

为探究矿浆电位对铜钼矿浮选的影响,采用黄铜矿、辉钼矿纯矿物作为样品,进行了矿浆pH、浮选药剂种类及用量对矿浆电位影响的研究。结果表明,黄铜矿上浮最佳矿浆电位为360 mV,pH为8。硫化钠、硫酸铵、碳酸钠三种调整剂按质量比1:1:1混合使用时,黄铜矿更易达到上浮电位区间。同时,当矿浆pH为9左右时,巯基乙酸能很好地抑制黄铜矿的上浮,并且对辉钼矿具有很好的选择性作用效果,有利于二者的分离。机理分析结果表明,在矿浆pH为8时,矿浆中生成大量的CuS是促进黄铜矿上浮的主要原因。      

Reclamation of Abandoned Coal Mine Waste in Korea using Lime Cake By-Products

Abstract.  There are hundreds of abandoned coal mines in Korea's steep mountain valleys. Enormous amounts of coal waste from these mines were dumped on the slopes, contaminating streams with sediment and acid mine drainage. A limestone slurry by-product (lime cake), which is produced during the manufacture of soda ash, was investigated for its potential use in reclaiming the coal waste. The lime cake is fine grained, has low hydraulic conductivities (10^-8 to 10^-9 cm sec^-1), high pH, high electrical conductivity, and trace amounts of heavy metals. A field experiment was conducted; each plot was 20 x 5 m in size on a 56% slope. Treatments included a control (waste only), lime (CaCO₃), and lime cake. The lime requirement (LR) of the coal waste to pH 7.0 was determined; treatments consisted of adding 25, 50, and 100% of the LR. The lime cake and lime were applied either as a layer between the coal waste and topsoil or mixed into the topsoil and waste. Each plot was hydroseeded with grasses, and planted with trees. In each plot, soils, surface runoff, and subsurface water were collected and analyzed, and plant cover was measured. Lime cake treatments increased the pH of the coal waste from 3.5 to 6, and neutralized the pH of the runoff and leachate of the coal waste from 4.3 to 6.7. Moreover, the surface cover of seeded species was significantly increased; sufficient acidity in the coal waste was neutralized in the 25% LR plots to allow seed germination.     

The effects of Ca(II) and Mg(II) ions on the flotation of spodumene using NaOL

The effects of Ca(II) and Mg(II) ions on the flotation of spodumene using sodium oleate (NaOL) as the collector were investigated by micro-flotation tests, zeta-potential measurements, absorption measurements, Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) analyses. The micro-flotation results indicated that the pH value has a significant influence on the activation of spodumene minerals by Ca(II) and Mg(II) ions. Good floatability of spodumene was obtained with Ca(II) and Mg(II) ions at a pH of 12.5 and 10.0, respectively. In strongly alkaline solutions, Ca(II) and Mg(II) ions readily form hydroxy complexes (CaOH(I) and MgOH(I)) and precipitates (Ca(OH)₂ and Mg(OH)₂). FT-IR and XPS analyses revealed that the hydroxy complexes and the precipitates adsorbed onto the spodumene surface. These species contributed to the formation of oleate complexes and thus increased the amount of collector adsorption and the floatability of spodumene.     

国外某高硫低锌尾矿锌强化回收试验研究

国外某高硫低锌尾矿中含锌2.69%、含硫47.08%,脉石矿物主要为滑石并且含有大量黄铁矿,硫含量过高是导致该矿石浮选指标差的主要原因。实验室通过条件试验指出石灰用量不足、硫酸铜用量过大导致现场精矿Zn品位低,并通过调整药剂用量、使用组合捕收剂以及添加黄铁矿辅助抑制剂Kg-1显著提高了精矿Zn品位。在最佳药剂制度下,采用一粗三精一扫,中矿按顺序返回的闭路流程,其中扫选不添加石灰,其他药剂减半,三次精选均添加石灰500 g/t调节矿浆pH值,最终试验获得的闭路锌精矿产品中Zn品位为42.86%、Zn回收率为71.93%,达到选厂要求浮选指标,实现了对该高硫低锌尾矿锌的高效回收利用。通过闭路试验探究有无Kg-1的添加对闭路锌精矿Zn品位的影响,试验结果指出Kg-1的引入能有效阻碍浮选过程中黄铁矿的上浮,显著提高锌精矿Zn品位。相对于未加Kg-1的闭路试验,锌精矿Zn品位提升13.76%,说明Kg-1是一种有效的黄铁矿抑制剂。Kg-1是一种有机小分子抑制剂,其分子头基有硫亲固原子,通过水解产生R-CSS^-,能与被硫酸铜活化的黄铁矿表面的Cu²⁺和F...     

浮选过程pH的控制

在浮选过程中,矿浆pH值是影响产品质量和回收率的一个重要因素。本文采用pH检测仪表、石灰添加装置、控制系统和MFA软控制器实现浮选作业矿浆pH控制,取得了良好效果。     

Application of flotometry for characterizing flotation in the presence of particles aggregation

Different size fractions of coarse magnetite were floated in water in a monobubble Hallimond tube with an increasing dosage of sodium oleate (Na01), diethyl dixanthate ((EtX)₂), and hexadecane. All maximum recovery (R_m) vs collector concentration curves plotted for various size fractions were similar in shape having zero recovery at a low and high collector concentration with a maximum recovery in between at a characteristic collector dosage c_m, which provides maximum hydrophobicity of the system. Properties of the studied flotation system and literature data indicated that the cessation of magnetite flotation with a high dosage of Na01 is due to hydrophilic layers of oleate ions sorption, while in the other two systems it is due to oil agglomeration of the solids. The values of the maximum particle size which can still be floated (a^m₅₀), taken from the maximum recovery vs particle mean size at the concentration equal to c_m and R_m=50%, seems to be the parameter which well characterizes any solid-collector-water flotation system because this value derives mainly from the hydrophobic properties of the flotation system and particle density in water, ^′. The a^m₅₀ value and the so-called “flotometry equation” (for our Hallimond tube in the form L_m = a^m₅₀^′) were used for calculation of the parameter L_m which in turn was used for a comparison of the floatability of magnetite with different collectors and subsequently with other flotation systems. The values of parameter L_m indicated that magnetite floatability increases in the order: collectorless (mechanical carryover), flotation with (EtX)₂, flotation in the presence of hexadecane, and oleate flotation. It was established that the floatability of magnetite with Na01 is equal to the floatability of galena with (EtX)₂ and very similar to the collectorless floatability of Teflon. Floatability of the above three systems is most likely the maximum possible floatability of a solid in an aqueous environment.     

Effect of thermal stability on the flotation response of sodium carbonate salts

Laboratory microflotation experiments show that flotation of certain sodium carbonate salts with cationic and anionic collectors is possible if the salts are thermodynamically stable under the prevailing experimental conditions. Sodium carbonate monohydrate can be floated up to 100% recovery with cationic dodecyl amine hydrochloride (DAH) and anionic sodium dodecyl sulfate (SDS) collectors at temperatures above 40 °C. Sodium carbonate decahydrate floats to a maximum yield of about 30% with 1×10⁻³ M DAH and to 17% with 1×10⁻⁴ M SDS even at room temperature where it is thermodynamically stable. Trona, the double salt of sodium carbonate and bicarbonate, does not float at room temperature in its saturated solution with either collector. Complete flotation of sodium bicarbonate in its saturated solution at pH 8.3 occurs with both DAH and SDS at all temperatures. Complementary data on flotation, viscosity and FTIR studies reveal that in addition to the thermal stability, the flotation response is dictated by the relative contributions of viscosity and water structuring properties of soluble carbonate salts.     

Adsorbing colloidal flotation removing metals ions in a modified jet cell

The removal of Cu²⁺, Zn²⁺ and Ni²⁺ ions from synthetic wastewater with a modified Jameson cell (MJC) was studied using adsorption colloidal flotation (ACF). A colloidal dispersion of Fe (OH)₃ (formed in situ from FeCl₃) at pH 11 was used as an adsorbent colloid to ensure full adsorption and precipitation. The precipitates were flocculated with polyacrylamide and hydrophobised with sodium oleate and pine oil as a frother during the flotation stage. In the modified jet cell, the downcomer was sealed at the bottom with a diffuser, and the re-flotation of detached flocs and the probability of bubbles/particles capture was enhanced, which improved the recovery rate. As a result, the modified Jameson cell was more efficient (higher loaded carrier recoveries) than the conventional jet cell (CJC) in removing heavy metals ions. The physico-chemical characteristics, cell design and operating parameters were studied, and the removal efficiency was evaluated by monitoring the final concentration of ions in the treated effluent. The results indicated that the removal efficiencies of the MJC were approximately 95% and 98% for dilute (Cu²⁺, Zn²⁺ and Ni²⁺ concentration of 2 mg/L) and concentrated wastewater (25 mg/L of each ion), respectively. The optimal parameters included a Fe⁺³/ion ratio of 0.5 and a minimum air flow-rate/feed flow-rate ratio of 0.18. The results are discussed in terms of the physical and physico-chemical parameters, and the findings suggested that the proposed flotation technique has great potential for the treatment of wastewater.     

The hydrodynamics of an operating flash flotation cell

Key parameters for evaluating the hydrodynamic conditions within an operating flash flotation cell have been investigated. Profiles of the slurry at increasing depth within the cell have shown a strong trend of increasing slurry density (per cent solids) and coarseness (P₈₀), with a clear indication of segregation on the basis of particle specific gravity. Results of local gas dispersion measurements, taken with the Anglo-Platinum Bubble Sizer, show that bubble coalescence is occurring at shallower depths within the cell and there is a clear trend of decreasing gas velocity (J_g) with increasing depth at the axial location of measurement. Due to access restrictions gas dispersion measurements were taken close to the cell wall, but all data obtained falls well below the recommended minimum values for mechanically driven conventional flotation cells. However, the flash flotation environment is significantly different to a conventional cell, with higher per cent solids and a significantly coarser feed material, making this comparison qualitative (as unfortunately within the literature, there exists no other flash flotation data sets of this nature on which to base a comparison). The residence time distribution of solids indicates a significant amount of short-circuiting and/or internal recycle within the cell. Yet despite these findings, this cell contributes up to half of the pyrite recovery to the final concentrate at a very high grade.     

Ca2+对菱镁矿浮选行为的影响

为了尽可能消除难免离子Ca²⁺对菱镁矿浮选的影响，通过纯矿物浮选实验、Ca²⁺浮选溶液化学计算和红外光谱分析等方法，考察了油酸钠浮选体系下Ca²⁺对菱镁矿浮选行为的影响并分析其机理。研究表明：①在油酸钠浮选体系下，在矿浆7≤pH≤12情况下，Ca²⁺对菱镁矿浮选具有较强的抑制作用，且Ca²⁺浓度升高对菱镁矿浮选的抑制作用增强。②矿浆中的Ca²⁺是抑制菱镁矿浮选的主要组分。③在pH=10的碱性条件下，菱镁矿表面存在亲水的-OH吸收峰，证实Ca²⁺与菱镁矿发生了吸附作用。     

黄铜矿粗选指标对水玻璃超声波改性的响应及其机理

为阐明黄铜矿粗选指标与水玻璃超声波改性的内在关系,以超声波预处理的水玻璃为调整剂,进行了黄铜矿实际矿物的浮选试验,并采用pH值、黏度及红外光谱等手段对超声波预处理水玻璃溶液及矿浆浊度进行了表征。结果表明,黄铜矿的粗选回收率对超声波改性的水玻璃较为敏感。铜的回收率在水玻璃预处理时间为15 min作用时的敏感性最强,为85.33%,与未改性水玻璃的回收率相比提高了9.31%。超声波预处理可减小水玻璃溶液的pH值,并使其黏度降低0.36%,这有利于水玻璃在矿浆中的分散。此外,超声波预处理还可改变水玻璃溶液的中水分子的比例以及水玻璃官能团的组成,并使预处理后的水玻璃溶液中游离水羟基与H₂SiO₃中的Si-OH的相对比例分别提高7.81%和1.02%。游离水组份的增加有利于改善黄铜矿的疏水性及浮选效果,水玻璃有效成分H₂SiO₃中Si-OH的组份增加在一定程度上强化了对矿泥的分散作用,从而提高了粗选作业铜的回收率。研究对超声波技术在有色金属浮选领域的应用有一定参考意义。     

Statistical comparison of surface species in flotation concentrates and tails from TOF-SIMS evidence

The coverage of potassium isobutyl xanthate (IBX) and sodium diisobutyl dithiophosphinate (DBPhos) adsorbed on the surface of galena has been investigated by Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS). Differences in surface concentrations and distributions between particles and across individual particle surfaces were sought comparing flotation concentrate and tail samples.This study has shown that a large difference is found in collector adsorption for both IBX and DBPhos between different faces of galena particles. The amount of collector adsorbed on galena particles of different sizes was statistically inseparable. However, a large variation in collector concentration on particles of the same size was observed.Statistical analysis of DBPhos on galena particles in the first concentrate and tail indicated that TOF-SIMS can be used to quantitatively investigate the flotation response of galena based on hydrophobic/hydrophilic ratios for each particle. Differences between collector distributions on concentrate and tail samples can be statistically separated. TOF-SIMS data also produced various hydrophilic and hydrophobic indices derived from the selected pairs of related spectral measures: Ca⁺/Pb⁺, Al⁺/Pb⁺, PbOH⁺/Pb⁺, SO₃⁻/S₂⁻, DBPhos⁻/SO₃⁻. Linear regression and mean analyses were used to estimate these indices; the results correlated closely with the flotation response. Hydrophilic species concentrations such as calcium, aluminium and metal hydroxides were found to be statistically greater on tailings than on the concentrate particle surfaces. The method suggests that it will be possible to assess conditioning of sulphide surfaces for optimum selectivity.     

On the mechanism of the flotation of oxides and silicates

The mechanism of flotation of oxide and silicate minerals was established long ago as being due to the electrostatic attraction between the charged surface and the charge of the collector. What is less well established is the mechanism of the charging of the mineral surface. Most researchers have postulated that the adsorption of H⁺ is the cause. However, the adsorption model and its derivatives (such as the amphoteric and multisite-adsorption models), do not successfully describe the data for the zeta potential as a function of pH. In particular, these adsorption models have the following features that are not observed: (i) they are symmetrical about the point of zero charge, whereas the data is asymmetrical, (ii) they have an inflection at the pK_a values, leading to an asymptotic approach to the point of zero charge, whereas such an inflection is not observed, and (iii) they only fit the data in its extremes, that is, when the pK_a values differ by orders of magnitude, or are very close to one another. An alternative mechanism of charging is proposed here that is based on the dissolution of ions from and deposition of ions onto the mineral surface. It is shown that this model (a) fits the data, (b) is consistent with the thermodynamic model for reversible interfaces, (c) is consistent with the thermodynamics of the overall reaction and its solubility, (d) indicates reasons for the ageing of surfaces and (e) displays the observed features of zeta potential measurements as a function of pH, that is, it is pseudo-Nernstian and asymmetrical in nature. Application of the proposed theory is discussed for the flotation of quartz and corundum.     

A review of hematite flotation using 12-carbon chain collectors

A sample of naturally occurring, relatively pure hematite (98.5% Fe₂O₃) was used as a model for the study of the flotation of insoluble metal oxides. The isoelectric point of this sample was 2.7 and the point of zero charge was 6.7. A number of surfactants containing saturated 12-carbon chain groups were used as collectors over a wide range in pH.The flotation of this hematite with dodecanoic acid (lauric acid) showed a maximum recovery in the pH range 6–8.5, a sudden drop at pH 9, and a steady increase in recovery as the pH was raised from 9–12. The flotation of the hematite using potassium dodecyl hydroxamate showed a maximum recovery at pH 5.5, with little flotation at pH <3. AtpH >10, the recovery fell except at high additions of collector. The flotation of hematite using sodium dodecyl sulphate showed a high recovery for pH <6, a trough in recovery between pH 7 and 9, and a secondary maximum in recovery at pH 10. Different flotation behaviour was observed when sodium dodecyl benzyl sulphonate was used. Using ARMAC C, (a commercially available dodecyl ammonium acetate), a flotation maximum was observed at pH 8, with steadily decreasing recovery as the pH was raised or lowered from this value. These results are discussed in terms of the surface chemistry of the hematite and the solution chemistry of the various collectors used.     

Mineralogical and Geochemical Characterization of Mine Tailings and Pb, Zn, and Cd Mobility in a Carbonate Setting (Northern Tunisia)

Millions of tonnes of Pb–Zn ore flotation tailings and waste rock have been discharged at sites in northern Tunisia without concern for environmental issues. The tailings are dominantly fine grained (<125 μm), with high porosity and permeability. The tailings were characterized to assess base metal (Pb, Zn, and Cd) mobility. The relatively low percentage of iron sulphide and the dominance of carbonates in the matrices of the tailings indicated that only neutral mine drainage is likely. Batch sequential testing showed that the calcium and sulphate, which are the major ionic species in solution, are derived mainly from the dissolution of gypsum and not from neutralization of acidity generated by pyrite oxidation. Yet, despite the carbonate setting, the resultant neutral to slightly alkaline pH, and prolonged weathering, the studied flotation tailings maintain their capacity to release contaminants, notably Zn and Cd, into the environment. The amount of Zn that dissolves (2,400 μg L^?1, on average), though significant, is below the background concentrations in the Mejerda River and the environmental norms established for surface waters. Pb concentrations come close to the standards, but only Cd (18 μg L^?1, on average) sometimes exceeds current river water concentrations and environmental standards.