Effects of oils and lubricants on the flotation of copper sulphide minerals

The effects of the addition of oils and lubricants commonly encountered in mining and processing copper sulphide ores on the subsequent flotation of copper minerals was investigated by laboratory scale testing. The project arose as a result of intermittent uncontrollable frothing and a drop in selectivity observed at an Australian copper-gold concentrator. The addition of distillate to the grinding stage actually increased selectivity in the subsequent copper mineral flotation but other oils and lubricants used at the plant had detrimental effects on selectivity and frothing behaviour. A degreaser used in maintenance operations dramatically lowered copper grade and generated a very stable and sticky froth even at low concentrations. Similar detrimental effects on gold metallurgy were also observed. Mineralogical examination of flotation products verified that the decrease in grade of the concentrates was due to the flotation of free gangue minerals and not due to any liberation problems. Possible mechanisms for these effects aer discussed. Anecdotal evidence for these effects abound in discussions held with plant metallurgists, but little published data on these effects have been located.     

新疆某围岩蚀变型含泥金矿选矿试验

新疆某国有大型黄金矿山矿石特点为矿体极度破碎、原生泥和次生泥含量高,载金硫化矿浮选分离精度低,部分载金黄铁矿嵌布粒度微细且结晶程度较差,金的高效回收技术难度大。基于矿石工艺矿物学特性,取消原泥砂分选工艺,开发应用“全粒级粗磨粗选-中矿再磨单独选别-再选产品梯级返回”选矿工艺流程,强化泥质脉石高效抑制和载金矿物有效活化,应用泥质脉石抑制剂XJ-12和微细粒载金黄铁矿浮选增效剂AXJ-1,在原矿Au品位2.19g/t条件下,实验室全流程闭路试验获得Au品位30.30g/t、Au回收率86.28%的金精矿,有效降低细泥对浮选的干扰,提高难选目的矿物可浮性,实现了金的高效回收。     

Flotation of mixed copper oxide and sulphide minerals with xanthate and hydroxamate collectors

Sherwood Copper’s Minto Mine processes a high grade copper–gold deposit in Yukon, Canada. The ore mined is from a primary copper sulphide deposit with separate additional deposits of copper oxides. In conjunction with Ausmelt Chemicals, Minto is currently investigating options to recover copper oxide and sulphide minerals using flotation by blending their primary sulphide ore with oxide ores. The blend used in this laboratory scale investigation was 70% sulphide ore and 30% oxide ore on a weight basis. The copper sulphides present in the blend were bornite and chalcopyrite, while the oxides were malachite and minor azurite.From previous flotation investigations of mixed copper oxide and sulphide minerals using xanthate and hydroxamate collectors it was hard to distinguish the impact of the alkyl hydroxamate collector on sulphide recovery as the sulphide and oxide minerals occurred naturally together. In the case of the Minto operation the copper oxide and sulphide minerals occur in separate ore deposits and can be treated separately or blended together. This investigation has shown that using n-octyl hydroxamates (AM28 made by Ausmelt Limited) in conjunction with traditional sulphide collectors can successfully simultaneously recover copper sulphides and oxides by flotation from blended ore minerals. The copper sulphide recovery did not decrease when processing the blended ore compared to treating the sulphide ore independently. At a blend of 70% sulphide ore and 30% oxide ore, the rougher scavenger copper recovery was as high as 95.5%. The copper recovery from the blended ore using a mixture of collectors was shown to be superior to the recovery obtained using only xanthate after controlled potential sulphidisation.     

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.     

Classification of the Major Copper Sulphides into semiconductor types,and associated flotation characteristics

Recoverable economic copper sulphide minerals such as chalcopyrite, bornite, chalcocite and covellite often occur together in varying proportions in the major copper-bearing ores, and have individual flotation requirements and characteristics. Pyrite also occurs in these ores to varying extents as the sulphide gangue, and is problematic because of its natural tendency to float quickly and easily. In a bulk sulphide float, selectivity against pyrite is desirable, particularly if it does not host other paymetals such as gold or silver. At the same time it is a requirement to float all of the copper sulphides despite their electrochemical differences. The electrochemistry and semiconductor properties of these minerals are reviewed, together with implications for flotation with and without collector addition. Mixed collector systems for the improved flotation of these sulphides are proposed as a solution. The use of xanthate and dithiophosphate in the collector suite allows the co-existence of dixanthogen and free dithiophosphate radical because the latter has a higher redox potential requirement than xanthate to oxidize to the dithiolate. Because some of these minerals require dixanthogen, and others, free thiolate, to generate surface hydrophobicity, a bulk flotation of all the species becomes possible in the overlapping area of Eh and pH between the two dithiolate equilibrium lines on the Pourbaix Diagram. The arsenic-signature copper minerals are added to the study, since many copper operations encounter arsenic as a penalty element in the saleable concentrate. It is shown that the addition of arsenic to the copper and iron sulphides alters the semiconductor and electrochemistry properties, and in turn, its flotation characteristics. The degree of mineral association and liberation between these minerals can be a complicating factor due to textural associations, and should also be considered in the process as a next step.     

Current processing technology for antimony-bearing ores a review, part 2

On the basis of knowledge of the beneficiation properties of antimony minerals reported in the previous part of this article, this second half reviews the state of technology for separation of those minerals and summarizes experience from processing plants.The high density of antimony minerals and their tendency to grind to slime (hardness of 2.5 on Mohs' scale) make gravity separation in the mill circuit an interesting possibility for the first step in the process. Gravity concentration is already found in some process layouts, but there are undoubtedly more applications where modern gravity separation equipment could be used.Marketing considerations make separation of arsenopyrite an important part of the process in some cases. Special cleaning processes have been developed for the purpose, but more attention needs to be paid to selectivity in the primary Sb flotation. Because of the rise in gold prices, some antimony ores should really be viewed as gold ores with antimony as a by-product. In this context, cyanide leaching is an obvious step in addition to gravity separation, and the most logical procedure here would be first to separate the antimony at natural pH and then to leach out the gold with cyanide.The design of flotation circuits for beneficiation of stibnite is usually very straightforward: rougher, scavenger and two-stage cleaner flotation are usually enough to produce concentrates grading better than 60% Sb. Recycling circulating returns to the middle of the rougher flotation circuit offers an attractive way of obtaining high-grade concentrates while achieving high capacities.The choice of methods for depressing antimony minerals in complex sulphide ores depends on what kind of mineral is the predominant impurity. It ought to be possible to depress ferrous antimony minerals effectively in pyrite-selective environments.     

捕收剂BK—301浮选硫化矿回收铜,锌及伴生金银的研究

ＢＫ－３０１是一种新型的硫化矿复合捕收剂。对铜、锌硫化矿及伴生金银的浮选研究表明，由于该药剂在低碱度介质中兼有捕收能力适中和选择性好的特点，因此它有利于铜、锌的浮选分离和硫化铁矿物及伴生金银的综合回收。     

矿物浮选过程中的交互影响

复杂矿石体系中矿物间难以分离的主要原因是有用矿物的嵌布粒度太细,有用矿物与脉石矿物的共生关系复杂,要实现矿物之间的单体解离,首先必须对矿石进行细磨,从而造成矿石泥化现象以及矿物之间的相互罩盖,进而对矿物的可浮性产生交互影响,导致矿物分离困难。矿物浮选的交互影响是指复杂矿石浮选体系中两种以上矿物间相互吸附、表面转化等对浮选分离产生的影响。因此,要实现复杂矿物体系中有用矿物的选择性分离,首先必须摸清不同复杂矿石体系中矿物之间的交互影响规律,进而找到利用或消除矿物间交互影响的方法,最终达到提高分离选择性的目的。系统阐述了近年来在复杂铁矿石、菱镁矿矿石和钨矿石体系中不同矿物间的浮选交互影响规律的研究成果,以及浮选过程中不同类型复杂矿石中各矿物交互影响的晶体化学和表面物理化学机制,并提出了削弱或促进矿物之间交互影响和适于不同类型复杂矿石浮选分离的方法,建立了复杂铁矿石、菱镁矿矿石和白钨矿矿石中矿物浮选交互影响的理论体系。      

Mn~(2+)离子对细粒氧化锑矿物浮选的影响

本文通过浮选试验,ζ-电位测定,吸附试验等,初步研究了Mn~(2+)离子对细粒氧化锑矿浮选行为的影响。研究表明,Mn~(2+)离子对细粒氧化锑矿浮选具有良好的活化作用,不仅能大幅度提高浮选回收率,加迅浮选过程,而且能提高细粒氧化锑矿与主要脉石矿物——矽化灰岩浮选分离的选择性。     

A conceptual model for gold flotation

This paper is aimed at producing a conceptual model for gold flotation based on the discussion of a number of experimental results where the behaviour of free and refractory gold has been studied under different chemical and physical conditions. A review of the literature suggests that there have been numerous studies on the flotation of free gold particles and refractory sulphides, but these investigations have typically focused on the individual flotation behaviour of each gold bearing species in synthetic mixtures and not when they are present together in “real” ores in the same pulp. The model discussed here shows that the flotation of refractory gold follows a similar trend to the recovery of refractory pyrite and pyrrhotite and is mainly affected by chemical conditions in the pulp such as redox potential, aeration conditions, copper activation, reagent synergism and galvanic interaction. Refractory gold is usually recovered by true flotation that is hydrophobic particle-bubble attachment, unless under certain conditions the physical transport of water and gangue provides a washing effect and detaches some of the sulphide material from the air bubbles. The flotation recovery of free gold is largely affected by physical constraints like the shape and size of the particles, the degree of water and gangue transport to the froth, the stability of the froth, and the extent of bubble loading of sulphide particles which can provide a barrier towards the hydrophobic bubble attachment of free gold. In each individual study the results suggest that the recovery of free gold follows a proportional trend with regard to water and gangue recovery. However, there is an inverse relationship between the true flotation of free and refractory gold due to the fact that free gold particles cannot attach to air bubbles properly in the presence of physical barriers.     

方解石与共伴生矿物浮选交互影响研究进展北大核心

方解石与共伴生矿物常通过浮选方法分离,其分选效果取决于浮选药剂性能和矿物表面性质差异。然而,混合矿体系中矿物颗粒间存在交互作用,如异相凝聚或溶解组分吸附、迁移、反应等,影响高效浮选药剂选择性吸附和矿物间表面性质差异,是高效浮选药剂在实际矿石分选体系中失去选择性的一个重要原因,也是复杂矿石难以分选的一个重要因素。归纳综述了氧化物矿物、碳酸盐矿物和含钙盐类矿物与方解石浮选分离过程中的交互影响机制及调控方法,分析了含有方解石体系的矿物交互影响研究现状与发展趋势,为方解石与共伴生矿物高效浮选分离研究提供借鉴。     

DESIGNS AND PRACTICES OF NEW FLOTATION SEPARATION FLOWSHEETS OF SULPHIDE ORES

ＤＥＳＩＧＮＳＡＮＤＰＲＡＣＴＩＣＥＳＯＦＮＥＷＦＬＯＴＡＴＩＯＮＳＥＰＡＲＡＴＩＯＮＦＬＯＷＳＨＥＥＴＳＯＦＳＵＬＰＨＩＤＥＯＲＥＳＷａｎｇＤｉａｎｚｕｏ（ｍｅｍｂｅｒｏｆＡｃａｄｅｍｉａＳｉｎｉｃａ）ＢｅｉｊｉｎｇＧｅｎｅｒａｌＲｅｓｅａｒｃｈＩ...     

我国钽铌资源的特征及选矿技术

介绍了我国钽铌资源单一矿床少、共伴生矿床多、矿石品位低、钽铌矿物与其他矿物密切共生、钽铌矿床区域分布高度集中等突出特点。根据钽铌矿物与其他矿物密度的差异,以及钽铌矿物嵌布粒度的粗细等特点,归纳总结了钽铌矿物的回收工艺：对仅钽铌矿物密度大,且钽铌矿物嵌布粒度较粗的矿石,通常采用以重选为主的分选工艺;对有多种矿物密度大,且钽铌矿物嵌布粒度较粗的矿石,多采用重选与磁选、电选等相结合的分选工艺;对有多种矿物密度大,且钽铌矿物嵌布粒度较细的矿石,多采用以浮选为主的分选工艺。     

氧化锌矿物的表面性质与浮选关系研究综述

氧化锌矿石结构和共伴生关系复杂,表面性质相似,浮选分离难度较大。氧化锌矿中有用矿物异极矿或菱锌矿在浮选过程中难以与含钙脉石矿物方解石和白云石有效分离。因此,对异极矿、菱锌矿及其含钙脉石矿物的表面性质以及其与浮选行为之间的关系进行深入分析可为其高效浮选分离提供理论基础。系统介绍了异极矿和菱锌矿及其含钙脉石矿物表面性质的研究现状,主要包括矿物的表面断裂键、表面润湿性、表面能、表面电性、表面溶解性等,并评述了矿物表面性质与浮选之间的关系。其中,表面断裂键决定矿物暴露面的活性位点;表面润湿性决定矿物天然疏水性;表面能与矿物吸附药剂能力有关,吸附能越负,药剂与矿物表面的相互作用越剧烈;在浮选过程中,带与矿物表面相反的电荷的捕收剂容易通过物理吸附导致浮选;有用矿物表面溶解的金属离子会活化脉石矿物,导致浮选分离困难。最后,对氧化锌矿物表面性质的未来研究方向进行了展望。     

滑石的晶体化学研究及其在有色金属硫化矿选矿中的浮选现状和实践

滑石是有色金属硫化矿选矿中常见的脉石矿物之一。从研究滑石的晶体结构出发,分析了滑石具有良好的天然可浮性的原因,及对有色金属硫化矿的浮选的影响。目前多采取利用有效捕收剂对滑石进行优先浮选的方法,来减少滑石对后续流程中金属矿物回收的影响。对某滑石含量为13%的铜锌矿进行了滑石优先浮选的应用实践,滑石优先浮选基本脱除了矿石中的易浮脉石,滑石精矿中的铜、锌品位分别为0.17%、0.81%,铜、锌在滑石精矿中的损失率分别为2.11%、2.63%。     

某低炭质细粒级金矿石选矿试验

某低硫低炭石英脉型细粒级金矿石金品位为3.62 g/t,金主要为自然金,嵌布粒度主要为0.005~0.02mm,最大粒度为0.035 mm,以不规则柱状、粒状被包裹于石英边缘,石英和高岭土是矿石中的主要脉石矿物,其次是黄铁矿、褐铁矿、绢云母、炭等。采用重浮联合工艺流程进行了矿石的选矿工艺研究,确定的选矿工艺流程为1次摇床重选,1粗2精4扫、中矿顺序返回浮选流程,获得了金品位为295.45 g/t、金回收率为32.60%的重选精矿和金品位为46.64 g/t、金回收率为59.26%的浮选精矿,综合精矿金品位为66.51 g/t、金回收率为91.86%。     

Selective flotation of carbon in the Pb–Zn carbonaceous sulphide ores of Century Mine,Zinifex

Century Mine, operated by Zinifex, is one of the largest zinc and lead deposits in Australia. The ore contains sphalerite and galena as valuable minerals, and carbonaceous material is present among the gangue minerals. The presence of carbonaceous matter is detrimental to the concentration of zinc and lead by flotation. Therefore, preflotation, which is flotation in the absence of collector and prior to galena flotation, is employed to remove some of the organic carbon, some of which is naturally hydrophobic, from the flotation feed. The main issues affecting the effectiveness of preflotation are: (i) low carbon recovery, (ii) low selectivity against zinc, and (iii) very high frother (methyl isobutyl carbinol, MIBC) consumption. The present study revealed that: (a) most of the MIBC added during flotation disappears from solution due to its high adsorption onto ore particles and especially on fine carbon enriched particles which have high surface area, (b) the addition of diesel oil can reduce MIBC consumption by 50% (in laboratory flotation tests) and (c) polypropylene glycol (PPG 192) showed lower affinity for carbon surfaces due to this reagent’s higher hydrophilic/lipophilic balance, producing stable froths at 50% of the current MIBC addition.     

Implementation of regrind–flotation pre-treatment of the CIL feed in a copper–gold plant

A regrind–flotation pre-treatment method developed to improve performance of a CIL circuit at copper–gold concentrators has been implemented at plant scale at the Newcrest Telfer mine. Low gold recovery in the CIL circuit due to the occlusion of gold by iron sulphide gangue minerals was overcome by the fine grinding of the CIL feed. A post-regrind copper flotation stage recovered liberated copper sulphide minerals allowing lower cyanide consumption in the subsequent CIL circuit than by regrinding alone. Gold recoveries achieved during the laboratory development of the regrind–flotation pre-treatment method have been replicated during the commissioning of the full-scale plant.     

浅谈矽卡岩铜矿床特征及其难选矿石浮选技术

本文重点阐述了矽卡岩铜矿矿床成因和矿床特征、难选矽卡岩铜矿的工艺矿物学特点和难选矽卡岩铜矿的浮选技术。指出应加强研究矿床学理论与选矿学理论的内在联系,尤其是将矿床物理化学特征与浮选理论相结合,对于浮选工艺流程制定具有重要的宏观指导意义。矽卡岩铜矿床相比其他铜矿床类型而言,矿体连续性差,矿物组成成分复杂,杂质元素较多,脉石矿物对于浮选的影响较大,且有中细粒嵌布结构,总体上相对难选一些。针对难选矽卡岩铜矿,浮选研究中应重点考虑磨矿流程的制定、铜硫分离、铜与易浮脉石分离等问题。     

Coal reverse flotation. Part I: Separation of a mixture of subbituminous coal and gangue minerals

Reverse flotation of a subbituminous coal/gangue mixture and the effect of various factors on the reverse flotation have been investigated. The results showed that the separation of coal from gangue by reverse flotation was possible and good selectivity was achieved, but up to 6 kg/t of DTAC (dodecyltrimethyl ammonium chloride) were needed. In addition, the separation could only be achieved through stage additions of DTAC. Otherwise, even higher dosages of the collector could not provide a good separation.Dextrin was needed to depress coal, so the selectivity was improved. The selectivity was further enhanced by addition of a ferric silicate hydrosol which activates calcite and dolomite in a cationic flotation. Conditioning with the ferric silicate hydrosol promoted the activation. The flotation was best in alkaline pH range.