The effect of high intensity conditioning on the flotation of a nickel ore,part 2: Mechanisms

It has been found that High Intensity Conditioning (HIC) significantly increases the flotation rate of pentlandite from a nickel ore. A systematic investigation of slime surface coatings and the effect of HIC on surface cleaning of the nickel ore was carried out using Scanning Electron Microscopy (SEM), Image Analysis, X-ray Diffraction (XRD), and a sieving technique. The sieving technique was established to semi-quantitatively determine the state of slime (< 3 to 5 μm) surface coatings using a combination of sieving and laser diffraction particle size analysis. It was found that hydrophilic gangue slimes were present on both pentlandite and gangue mineral surfaces prior to HIC. The surface coating by the slime mineral particles was apparently non-selective towards any particular mineral. High intensity Conditioning removed slimes from the mineral particle surfaces, the amount removed depending upon both agitation intensity and time.     

Elimination of the adverse effect of cement filling on the flotation of a nickel ore

In China, most of the nickel sulphide deposit is spatially related to ultrabasic rocks and the cementation filling method is used in the process of mining. However, the cement filling from the mine back fill often gets into the ore and interferes with the pentlandite flotation. In this work, the effect of the cement filling on the flotation performance of a nickel ore was studied and ammonium sulphate was used to eliminate this adverse effect. The flotation result shows that the pentlandite recovery decreased from 87% to 65% with the increase of the content of cement filling from 0% to 8%. The addition of ammonium sulphate was shown to improve the flotation performance of pentlandite that depressed by cement filling. This result points out a problem often encounter in the flotation of a nickel sulphide ore and finds a solution to it.     

分支浮选在低品位镍矿中的应用研究

针对本试验镍矿石品位低、粒度细的特性,采用分支(两支)浮选工艺来提高入选矿石品位的流程对该矿石进行了深入研究。通过研究,采用新合成抑制剂GL-2,分支浮选闭路试验可获得镍精矿品位5.18%、回收率74.16%的较好指标,按硫化矿计回收率高达96.56%。在镍精矿品位保持基本不变的情况下,分支浮选比单支浮选药剂用量降低10%~34%不等,产率提高0.34%,回收率提高5.89%,效果较好,对同类型矿产资源的综合利用具有较好的推广应用价值。     

双龙镍蛇纹石矿脱泥浮选试验研究

针对双龙镍蛇纹石矿进行Ni浮选综合回收试验研究,蛇纹石矿磨矿易泥化,影响Ni浮选指标,通过试验对比表明浮选前需脱泥。探讨摇床脱泥工艺条件,确定了摇床粗选-粗选中矿再选-摇床混合精矿浮选工艺流程。然后通过磨矿细度、浮选药剂制度调整,最终获得了精矿Ni品位8.20%,Ni回收率14.09%的综合利用优良指标。     

The effect of grinding conditions on the flotation of a sulphide copper ore

The challenge of process development for the beneficiation of Salobo’s copper ore started in 1978 and the studies still go on. Copper is predominantly present as secondary minerals, such as chalcocite, bornite, and digenite, and liberation requires very fine grinding. These minerals may undergo rapid oxidation at the alkaline pH range and under mildly oxidising conditions. The oxidation products may adsorb onto the minerals altering their surface characteristics, flotation behaviour, and may also significantly modify the mechanisms of interaction between the minerals and the collector. These facts impair the flotation process performance and increase the reagents consumption, the required flotation cells volume, and the overall processing costs. This paper describes the effect of grinding conditions on the flotation performance. Different media and mill construction materials were tested at bench scale aiming at evaluating the effects of the pulp electrochemical potential and the availability of iron oxide and hydroxide compounds on the flotation response. The results indicated that the grinding process affects significantly the flotation metallurgical performance of Salobo’s ore. The conditions that yielded the highest levels of copper recovery and the fastest flotation kinetics were rubber lined steel mill and stainless steel media.     

Selective sulphidation and flotation of nickel from a nickeliferous laterite ore

The sulphidation of a nickeliferous lateritic ore was studied at temperatures between 450 and 1100 °C and for sulphur additions of 25–1000 kg of sulphur per tonne of ore. The experiments demonstrated that the nickel could be selectively sulphidized to form a nickel–iron sulphide. It was found that both the grade and the sulphidation degree largely depended upon the temperature and the sulphur additions, with temperatures above 550 °C exhibiting the highest nickel sulphidation degrees and grades. A DTA/TGA with mass spectrometer was used to further elucidate the nature of the phase transformations that occurred upon heating of the ore in the presence of sulphur.It was found that at low temperatures, the Fe–Ni–S phase was submicron in nature and heating to temperatures between 1050 and 1100 °C allowed for the growth of the particles, due to the increased sulphide mobility associated with the formation of a liquid sulphide matte phase, containing dissolved oxygen. Flotation studies conducted on 60 g samples showed that the sulphides responded to flotation with maximum grades of up to 6–7 wt.% nickel being achieved. Recoveries were approximately 50% on a sulphide basis and it was determined that the low nickel grades were due to the entrainment of magnetite fines.     

The entrainment effect on the performance of iron ore reverse flotation

An iron ore mineral processing plant in Brazil treating Itabirite ore was assessed by sampling a circuit consisting of Wemco 144 mechanical cells, as part of the AMIRA P9P collaborative research project. This paper presents and discusses the results of entrainability, water recovery and quartz and hematite grades associated to hydrodynamic parameters. The results indicated strong correlation between water recovery and hematite losses which was intensified by the operating conditions of the circuit.A potential alternative to reduce the hematite losses through entrainment and to increase quartz removal was to modify the traditional circuit design to treat rougher and cleaner/recleaner tails in different stages. In addition, the scavenger residence time must be matched to the quartz floatability. Changes to design and operation of these circuits are needed to sustain concentrate recovery and grade as iron ores become finer.     

Pentlandite oxidation in the flotation of a complex nickel ore in saline water

Flotation of a low grade pentlandite ore containing large amounts of serpentine minerals from Western Australia was conducted with process water having high ionic strength. Nickel recovery was low in the flotation of both fine and coarse fractions. X-ray photoelectron spectroscopy (XPS) analysis indicated that oxidation occurred on both fine and coarse pentlandite particles. To reduce pentlandite oxidation, sodium hydrosulphide (NaHS) and dithionite (Na₂S₂O₄) were added during grinding. It was found that NaHS improved both pentlandite and serpentine mineral flotation and deteriorated pentlandite separation from serpentine, whilst Na₂S₂O₄ improved pentlandite flotation without affecting serpentine flotation and therefore increased pentlandite separation from serpentine.     

高品位铜矿浮选流程设计改造

为了适应原矿品位不断升高的需要,先后两次对原有浮选流程进行了技术改造,通过再次改造,采用分支粗选流程,克服了因分级机溢流不稳定而对浮选带来的新的困扰,该流程能够更好地适应生产的需要,最终达到了流程改造的目的,取得了较为理想的效果,尾矿品位进一步降低了0.08%,铜回收率提高了0.60%,铜精矿品位提高了6.42%,减少脱水压滤量18.54%,降低铜冶炼费用18.54%。     

蛇纹石型硫化铜镍矿浮选理论与技术研究进展

含蛇纹石脉石的硫化铜镍矿是我国镍资源的主要来源。蛇纹石质软,易泥化,在硫化铜镍矿浮选常用的弱碱性pH区间,脉石矿物蛇纹石表面荷正电,而硫化矿物表面荷负电,二者之间存在较强的静电吸引作用,容易发生异相凝聚。异相凝聚导致蛇纹石矿泥罩盖在硫化矿物表面,抑制了硫化矿物的浮选。脱附硫化矿物表面罩盖的蛇纹石矿泥是提高该类型硫化铜镍矿回收率的关键。脱附罩盖矿泥的方法有化学脱附法和物理脱附法。化学脱附法是利用六偏磷酸钠、碳酸钠、羧甲基纤维素、水玻璃等化学药剂改变蛇纹石表面电性,使蛇纹石与硫化矿物之间的相互作用由吸引变为排斥,从而消除蛇纹石对硫化矿物的抑制作用。物理脱附法是利用流体力场和超声外场的作用脱附硫化矿物表面罩盖的蛇纹石矿泥,消除蛇纹石对硫化矿物的抑制作用。根据该类型硫化铜镍矿的矿石特点及相关理论研究开发的酸法浮选、脱泥浮选等浮选技术,取得了较好的选别效果。     

The flotation of magnetic and non-magnetic pyrrhotite from selected nickel ore deposits

The non-stoichiometric sulfide mineral pyrrhotite (Fe_(1?x)S), common to many nickel ore deposits, occurs in different crystallographic forms and compositions. A series of pyrrhotite samples derived from Canada, South Africa and Botswana whose mineralogy is well characterised, were selected here in order to develop the relationship between mineralogy and flotation performance. Using both oxygen uptake and microflotation tests, the behaviour of the different pyrrhotite types was compared in terms of the effect of pH and collector addition. Non-magnetic pyrrhotite was less reactive in terms of its oxygen uptake and showed the best collectorless flotation recovery. Magnetic pyrrhotite was more reactive and showed poor collectorless flotation performance that could be improved with the addition of xanthate collector, but only if it was not already passivated. These differences are interpreted to be a result of pyrrhotite mineralogy. This has implications that may aid the manipulation of pyrrhotite flotation performance in processing operations.     

Dispersion effect on a lead–zinc sulphide ore flotation

This investigation was performed with samples from a lead–zinc sulphide deposit aiming at studying the influence of the dispersion degree of the particles in the pulp on lead and zinc flotation. Samples of ore and also of the minerals sphalerite, galena, pyrite, and dolomite were selected for the experiments. Nine types of dispersing agents and six blends among them were employed.A set of three dispersing agents was selected for the lead flotation and another set of three was chosen for zinc flotation. The criteria for the reagents selection were: high dispersion degree for galena and low for the other species, high dispersion degree for sphalerite and low for the other species, low dispersion degree for pyrite and high for the other species, and high dispersion degree for all species.Lead flotation experiments were performed under three conditions aiming at verifying the influence of the dispersing agent, of the pH, and of sodium carbonate. The zinc flotation tests were carried out at pH 10.5, modulated with lime.The use of dispersing agents in lead flotation did not improve the overall efficiency of the circuit for, despite improving the lead metallurgical recovery, they increase significantly the zinc losses in the lead concentrate.Sodium carbonate presented a low dispersion degree and did not affect the lead flotation results when compared with those achieved at natural pH and at pH 9.8 modulated with lime.Two dispersing agents were particularly effective in zinc flotation: dispersant 3223, a sodium polyacrylate, and sodium hexametaphosphate. Both reagents significantly enhanced zinc recovery without impairing the concentrate quality.     

湖南醴陵某高砷金矿浮选试验研究

湖南醴陵某高砷金矿含Au 2.85g/t,含As 0.2%,金主要以自然金形式存在,矿石中主要金属矿物为黄铁矿和毒砂。针对该矿性质进行了抑砷浮金试验研究,试验采用亚硫酸钠+腐殖酸钠作毒砂抑制剂,丁黄药+丁铵黑药作含金矿物捕收剂,在磨矿细度为-74μm 65%的条件下,闭路试验获得含Au 112.30 g/t、含As 0.27%的金精矿,金回收率85.20%,脱砷率达到97.56%,获得了较好的试验指标。     

高含碳金矿石浮选工艺流程试验研究

某高含碳金矿(碳品位6.68%),金共生有用矿物为黄铁矿、毒砂以及微量的石墨,一部分黄铁矿包裹在碳质物中。采用两次粗选、粗精矿1两次精选、粗精矿2四次精选、三次扫选的混合浮选工艺流程,获得金精矿(金精矿1+金精矿2)金品位42.18g/t、银品位46.70g/t,金回收率85.87%,银回收率62.86%的浮选指标,在回收金的同时综合回收了银。此工艺流程为含碳金矿选矿厂提供了一个易于工业化实施的工艺流程。     

The effect of zinc cyanide on the flotation of gold from pyritic ore

In gold processing plants, the process water contains a considerable amount of weak acid dissociable (WAD) cyanide species. The cyanide-containing water recycled to flotation circuits has a deleterious effect on mineral flotation. Zinc cyanide can be a major constituent of the process water due to the cyanide leaching of zinc minerals and the zinc cementation applied to precipitate gold and silver. In the present study, the effect of zinc cyanide on the flotation of gold from a pyritic ore was evaluated and the competitive adsorption between zinc cyanide species and the collector, potassium amyl xanthate (PAX) or Aerophine promoter (3418A), on gold was studied by surface enhanced Raman spectroscopy (SERS). It was found that free cyanide did not depress the flotation of liberated gold, but zinc cyanide with a CN/Zn ratio of 2 did. The depression of gold flotation by zinc cyanide was due to the preferential adsorption of Zn(CN)₂ on gold surface over either 3418A or amyl xanthate in the solution, rendering gold surface hydrophilic.     

The effect of the design of a secondary grinding circuit on platinum flotation from a UG-2 ore

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.     

OP表面活性剂在磷矿浮选脱硅中的增效作用

为了研究辛基酚聚氧乙烯醚(OP)系列表面活性剂对油酸钠浮磷脱硅的增效作用,选用不同的环氧乙烷加成数的OP表面活性剂来复配油酸钠,通过纯矿物浮选试验和实际矿物浮选试验,来选取最佳的OP表面活性剂以及复配比例,通过泡沫性能测试、表面张力测定以及红外光谱,来探索OP表面活性剂的增效机理.纯矿物浮选试验表明,OP系列表面活性剂...     

某难选金矿高效浮选工艺可行性研究

某矿山矿石为微细粒蚀变岩型难选金矿。经过多年的建设、工艺优化和技术改造,浮选回收率由生产初期70%提高至81.57%。近年来,选矿指标难以有质的提升。为了提高该矿山的选矿指标,采用工艺矿物学研究结合工艺流程考察,总结分析选矿指标难以有效提升的主要原因是原矿金嵌布粒度微细、泥质矿物含量高,且旋流器底流金循环量大,造成微细粒金难以单体解离、已解离的单体目的矿物表面受到污染而随着浮选尾矿流失。通过开展闪速浮选+优先浮选+分支浮选高效浮选工艺可行性研究,有效解决了该矿山选矿厂矿石的过磨和欠磨问题,最终获得金精矿品位为38.84g/t、回收率为86.83%的浮选指标。结合该矿山选矿厂现有工艺流程和设备特点,进行选矿厂工艺技改可行性研究,通过高效浮选工艺技术改造,该选矿厂回收率可提高5.26%,年可新增产值880余万元。     

微细粒蛇纹石矿泥在含铂钯铜镍硫化矿浮选中的影响

通过分析和计算,发现蛇纹石对镍黄铁矿和非硫化矿脉石矿物粗颗粒表面的黏附是非选择性的,都有可能存在。而机械夹杂在有用矿物的疏水絮团中,相对来说比较容易除去。但矿泥在有用矿物粗颗粒表面的罩盖,通过计算发现这个黏附力比较大,难以除去。通过机理分析认为,造成矿泥罩盖的黏附力取决于：①矿泥颗粒的性质;②粗颗粒表面粗糙度;③镍黄铁矿表面氧化程度和＂补丁＂数量。     

低品位钼矿煤油气溶胶加药浮选规律的研究

本研究针对某低品位钼矿,煤油捕收剂采用气溶胶形式进行加药,主要从磨矿细度、矿浆浓度、pH值和起泡剂用量等浮选工艺条件,对煤油气溶胶加药浮选过程的影响进行了系统的研究。试验结果表明:磨矿细度、pH值、矿浆浓度和起泡剂用量等浮选工艺条件对于传统浮选和气溶胶浮选过程的影响规律基本相似,但两种浮选技术对于各浮选工艺条件的适应能力存在较大差异。与传统浮选技术相比,气溶胶浮选技术对于磨矿细度和矿浆浓度的变化,表现出了较好的适应能力;气溶胶浮选技术对于pH值的变化没有体现出良好的适应能力,只有在合适的pH值条件下才能发挥其优势;起泡剂用量对于气溶胶浮选影响较大,用量过少不利于煤油气溶胶加药浮选,良好的成泡环境对于气溶胶浮选过程是有利的。