Assessment of the floatability of chalcopyrite,molybdenite and pyrite using biosolids and their main components as collectors for greening the froth flotation of copper sulphide ores

Biosolids and representative compounds of their main components – humic acids, sugars, and proteins – have been tested as possible environment-friendly collectors and frothers for the flotation of copper sulphide ores. The floatability of chalcopyrite and molybdenite – both valuable sulphide minerals present in these ores – as well as non-valuable pyrite was assessed through Hallimond tube flotation tests. Humic acids exhibit similar collector ability for chalcopyrite and molybdenite as that of a commercial collector (Aero 6697 promoter). Biosolids show more affinity for pyrite. The copper recovery (85.9%) and copper grade (6.7%) of a rougher concentrate obtained using humic acids as main collector for the flotation of a copper sulphide ore from Chile, were very similar to those of a copper concentrate produced by froth flotation under the same conditions with a xanthate type commercial collector. This new and feasible end-use of biosolids and humic acids should be new environment-friendly organic froth flotation agents for greening the concentration of copper sulphide ore. Now, further research is needed in order to scale current laboratory assays to operational mining scales to determine efficiencies to industrial scale.     

Flotation frother mixtures: Decoupling the sub-processes of froth stability,froth recovery and entrainment

The flotation process consists of two distinct phases: the pulp and froth phase. One of the main roles of the froth phase is to create a suitable environment for the separation of floatable, valuable minerals from non-selectively recovered, entrained gangue minerals. As a result the froth phase plays a significant role in the metallurgical performance of industrial flotation cells. Froth stability is important for the recovery of valuable minerals. However, a stable froth may contribute to increased entrainment and, consequently, a lower grade.This study compares the effect of frother mixtures with that of their single component frothers on the froth stability, froth recovery and entrainment of a platinum-bearing UG2 ore using polyglycol and alcohol frothers. The study showed that frother mixtures resulted in a greater froth stability than either of their component frothers. The increased froth stability was reflected in increased froth recoveries and greater overall recoveries. However, the important aspect in the use of frother blends was that they altered the froth structure and resulted in a lower degree of entrainment. This, together with the increased recovery, resulted in higher grades of valuable mineral recovered to the concentrate when using the frother mixtures.     

The effect of frother blends on the flotation performance of selected PGM bearing ores

Concentrators processing PGM bearing ores make use of polysaccharide depressants to reduce the recovery of the undesired naturally floatable gangue minerals, mainly silicates, present in the ore. Recent work has shown that high depressant dosages can completely depress naturally floatable gangue and thus prevent it from reporting to the concentrate. These high depressant dosages can, however, have a negative effect on the recovery of valuable minerals present in the ore by reducing the stability of the froth. In order to counterbalance the effects of depressant addition, frothers are added. It is, however, preferable to maintain independent control over bubble size and froth stability which is difficult to achieve with only one frother. An alternative strategy is to use a blend of frothers, e.g. a weaker frother in combination with a stronger frother. Such a system allows an additional degree of freedom: changing the ratio of the two frothers provides more independent control of bubble size and froth stability. This study demonstrates through the use of batch flotation tests how blending low molecular weight alcohols with commercially available frothers impacts the solids and water recovery, as well as the valuable mineral recovery and concentrate grade in different PGM ores. Higher water and solids recoveries together with higher valuable mineral recoveries (>90% copper and >70% nickel) were obtained from tests using frother blends.     

The effect of the reagent suite on froth stability in laboratory scale batch flotation tests

In batch flotation tests conducted on ores from the Merensky reef, changes in froth stability invariably occur with variations in the reagent suite. The main reagents are collectors (primary and secondary), activators, depressants and frothers. Since the particles entering and leaving the froth in a batch flotation system are continuously changing, the stability of the froth can vary. Under these conditions the simplest measure of froth stability is the measure of water recovery at a fixed froth height. The batch flotation system developed at UCT allows for the separation of gangue which is entrained relative to gangue which is floated. It has been found that the presence of naturally floatable gangue (NFG) leads to froth stabilisation, whereas the presence of hydrophobic sulfide minerals may lead to destabilisation of the froth depending on the hydrophobicity (contact angle) of the sulfide minerals. This can vary with ore type since particle shape and amount of particles present can influence the extent of destabilisation. At low depressant dosages sodium isobutyl xanthate (SIBX) always results in lower froth stability than sodium ethyl xanthate (SEX). The frothing nature of dithiophosphate leads to increased froth stability and the addition of copper sulfate results in destabilised froths. Increasing depressant dosage reduces the stabilising influence of NFG and the depressant type (guar gum or CMC) also affects froth stability. Frother can be used in an attempt to overcome the destabilising effects of high depressant dosage. This work examines the effect of variations in the reagent suite and uses water recovered at a fixed froth height as an indication of froth stability in order to analyse these effects on the recovery of sulfide minerals, floatable gangue and entrained gangue.     

近年浮选进展

通过浮选相关文献量的分布比较，从数量上描绘了浮选近5年的发展的概貌。重点评述了浮选以下几方面的发展：浮选设备（浮选机、浮选柱和磁力浮选设备）、浮选新药剂（捕收剂、起泡剂和调整剂）、泡沫中分选（粗粒浮选新方法）、载体浮选、无捕收剂浮选、物理作用（外加电场、磁化、超声波等）与浮选、生物浮选（生物捕收剂和调整剂）、浮选泡沫图象、硫化矿和铝土矿浮选等。此外，简述了国内近年浮选工业实践的进展。     

Investigation of the interactive effects of the reagent suite in froth flotation of a Merensky ore

Interpretation of the behaviour of reagents in flotation is made complex by the existence of secondary effects, which can override the desired effects that enable effective separation, in addition to a predominant role of a flotation reagent, and the incomplete liberation of the mineral particles. Moreover, accumulation of dissolved ions due to the water recycle and reuse practice in processing circuits, which alters the chemical environment in the pulp and impacts the overall performance of the process, adds to this complexity. Therefore, it is often challenging to precisely assess individual contributions of the reagents to the overall performance, and hence the need for a holistic approach in evaluating the behaviour of reagents in flotation. Factorial design of experiments offers such an approach. This study used a factorial design approach in an effort to determine the interactive effects between chosen flotation reagents; collector, depressant, frother and water quality on the metallurgical performance of a Merensky ore. Increasing the ionic strength of the plant water increased recoveries, and the effect on decreasing concentrate grade was minimal, therefore the practice of water recycle and reuse should not impose any adverse impact during beneficiation of the PGM-bearing ore from the Merensky reef. It was also observed that higher recoveries were obtained with high ionic strength plant water than high frother dosage, indicating that the use of saline water in froth flotation of certain ores can replace the use of frothers, thus reducing costs. The factorial design approach can be useful in evaluating the simultaneous effects of such variables in the flotation process, thereby giving better understanding of their overall effect on the whole process.     

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.     

新型起泡剂250A对安徽某铜矿石的浮选效果

250A是中国矿业大学新研制的一种新型、价廉、易降解、低污染的选铜起泡剂,为了检验其高效性,以安徽铜陵某低品位原生铜矿石为试样进行了选铜试验。在磨矿细度为-0.074 mm占75%的情况下,以条件试验确定的药剂用量为粗选用量,参照现场工艺流程进行了2种起泡剂的浮选效果对比试验。结果表明：250A总用量为241 g/t的情况下,铜精矿铜品位和铜回收率分别为21.56%和87.32%;松醇油总用量为360 g/t的情况下,铜精矿铜品位和铜回收率分别为21.67%和87.19%。两相比较可知,250A比松醇油更高效,有助于选铜企业降本增效。     

E908捕收剂优先浮选高硫含铜矿石的试验研究

在低碱度条件下,研究了以E908为捕收剂,腐殖酸钠为抑制剂对某高硫含铜矿石的优先浮选工艺。试验结果表明,捕收剂E908对硫化铜矿具有较好的捕收性能,腐殖酸钠是铜硫浮选分离时黄铁矿的优良抑制剂。全优先流程闭路试验得到铜精矿铜品位19.87%、银品位605.84g/t,铜回收率87.76%、银回收率84.51%的浮选指标。      

某难处理铜铅锌混合矿浮选试验及机理分析

摘 要：某难处理铜铅锌混合矿原矿含铜铅锌分别为0.71%、2.16%、1.25%,脉石矿物主要是石英和方解石。铜铅锌氧化率均较高,相互嵌布共生。经试验,采用一粗三精两扫的工艺流程,通过粗选加入500g/t硫酸铵活化及强化硫化氧化矿,1500g/t硫化钠硫化氧化矿的同时抑制矿泥,100g/t硫酸铜活化闪锌矿,最后通过600+150g/t异戊基黄药+丁铵黑药组合捕收剂综合捕收铜铅锌矿物,56g/t 2#油浮选,精选和扫选不加药,闭路试验获得了高于现场的浮选指标。混合精矿产品中铜品位分别为8.88%,回收率70.15%;Pb的品位为26.84%,回收率为77.62%;Zn的品位为9.51%,回收率为46.42%。铜铅锌矿被最大限度的回收。     

云南永善铜矿浮选试验研究

云南永善铜矿含铜0.503%,氧化率为23.46%,其中结合氧化铜占11.53%,属低品位混合铜矿。针对矿石性质进行了浮选试验研究,确定了适合于处理该矿石的最佳的浮选流程和条件。研究表明,以黄药为捕收剂,2#油为起泡剂,硫化钠为活化剂,水玻璃为抑制剂,Na2CO3为pH调整剂,采用一次粗选一次扫选四次精选的浮选流程获得了铜精矿品位为23.27%、回收率为87.43%的指标,为该矿的开发利用提供技术依据。     

西藏桑日混合铜矿石选矿试验研究及工业应用

在混合铜矿浮选时,添加螯合捕收剂B130,不但能减少硫化钠用量,而且能硫氧混选,简化选矿工艺流程,提高选矿厂的技术经济指标。桑日铜矿的选矿闭路试验和生产应用结果表明,B130对氧化铜矿物具有较强的捕收能力,它和黄药混用能产生协同效应,与传统硫化-黄药法相比,在铜精矿品位相当的情况下,可提高铜回收率6%左右,金回收率11%左右。     

新型起泡剂750B在铅锌矿浮选中的应用研究

针对铅锌矿浮选和浮选起泡剂的应用现状,研制出了新型浮选起泡剂750B。小型浮选对比试验及工业应用试验结果表明,在不改变工艺流程、不改变其它药剂制度的前提下,仅用750B起泡剂代替松醇油,在铅精矿铅品位相近时,可使铅回收率提高2.02个百分点;在锌精矿锌品位相近时,锌回收率提高0.22个百分点,经济和社会效益显著。     

江西某钼矿选矿试验研究

分析了江西某钼矿的有用矿物组成及粒度特征,通过试验确定了该矿物浮选分离的合适磨矿细度、粗浮选合适的捕收剂煤油和起泡剂松醇油的用量、1次精选的抑制剂Na2S的用量、1次扫选捕收剂煤油和起泡剂松醇油的用量,并对探索试验确定的1粗1扫6精闭路流程进行了试验,获得了钼品位45.23%,回收率85.14%的钼精矿。     

开发冬瓜山铜矿资源选矿原则方案探讨

冬瓜山铜矿石与冬瓜山和狮子山混合铜矿石的对比试验结果表明 ,冬瓜山铜矿石可以与狮子山铜矿石混合进行处理。首先采用选择性起泡剂BC浮出以滑石和蛇纹石为主的易浮脉石 ;然后使用选择性捕收剂BJ进行铜部分优先浮选 ,使用丁基黄药 +丁基铵黑药混合捕收剂强化铜硫混选 ;混合粗精矿再磨后应用BD1 组合抑制剂进行铜硫分离 ;混选尾矿经磁选和强化浮选脱硫 ,获得合格铜精矿、硫精矿和铁精矿。所提供工艺为合理开发冬瓜山铜矿资源提供了可靠依据     

福建川石金矿浮选试验研究及生产实践

福建川石金矿选矿厂前期采用常规浮选工艺生产金精矿,浮选采用一次粗选、三次精选、四次扫选工艺流程,丁基铵黑药和丁基黄药作为捕收剂、松醇油为起泡剂、硫酸铜为活化剂、石灰用作p H值调整剂,选矿厂尾矿中金品位为0.82g/t,金选矿回收率为61.87%。经过工艺流程的优化,调整为一次粗选、两次精选、三次扫选,捕收剂丁基铵黑药30 g/t,丁基黄药100 g/t,起泡剂松醇油30 g/t、SC 15 g/t。最终选矿厂尾矿中金品位降至0.28 g/t,金的回收率为87.32%,年增加经济效益可达1 259.42万元。     

从白云鄂博尾矿中浮选回收稀土

包钢白云鄂博选矿厂尾矿库内尾砂(-0.074 mm占41%)稀土含量丰富,主要稀土矿物为氟碳铈矿,REO品位为6.00%。为开发利用该尾矿中的稀土资源,采用浮选工艺进行了稀土回收试验。结果表明,采用浮选工艺回收试样中的稀土矿物是可行的;在磨矿细度为-0.074 mm占98%、矿浆pH=9(自然pH)条件下,以水玻璃和草酸为调整剂、8#药为捕收剂、2#油为起泡剂,采用1粗3精1扫、中矿顺序返回流程处理试样,可获得REO品位为22.23%、回收率为72.21%的稀土精矿,试验指标较好,可作为回收白云鄂博选矿厂尾矿中稀土资源的依据。     

起泡剂对硫化矿浮选的影响

研究了起泡剂MIBC、BK201、松醇油及2-乙基己醇对石英及黄铁矿单矿物浮选行为的影响, 并进行了实际矿石浮选试验。单矿物试验结果表明: 石英通过泡沫夹带进入浮选精矿, 而黄铁矿通过疏水上浮和泡沫夹带的双重作用进入浮选精矿。不同起泡剂作用下, 精矿中泡沫水回收率越高, 石英和黄铁矿的浮选回收率越高, 不同起泡剂对石英和黄铁矿具有不同的夹带效果, 使石英和黄铁矿浮选回收率最高的起泡剂分别为BK201和MIBC。实际矿石浮选试验表明: 浮选产率、精矿品位及回收率与泡沫水回收率密切相关, 泡沫水回收率增大, 精矿产率增大, 而品位降低。选择合适的起泡剂能够增加硫化矿物的回收率并降低石英的回收率, 获得较好的浮选分离效果。     

Case studies on the performance and characterisation of the froth phase in industrial flotation circuits

This paper deals with two separate case studies investigating the froth phase performance and characterisation of two industrial rougher/scavenger flotation circuits. Froth phase performance was quantified using a mass balance approach to estimate froth zone recovery. Measured characteristics of the froth phase included frother solution concentration determined by gas chromatography, and the time taken for an equilibrium froth sample to decay to one-half of its original froth height. The latter measurement is referred to as the ‘froth half-life’ and is strongly linked to froth stability. Special methods and techniques developed to preserve frother in solution and to measure froth half-life are briefly described. The frother type in the first case study was a mixture of straight and branched alcohols, whilst the frother type in the second case study was a mixture of alcohols, aldehydes and triethoxybutane. The first case study focussed on a flotation circuit treating a low grade ore containing only a small fraction of floatable copper sulphide minerals, while the second case study focussed on a flotation circuit treating a higher grade complex sulphide ore containing significant quantities of chalcopyrite, galena, sphalerite and pyrite.It was found that froth zone recovery of valuable mineral generally decreased down-the-bank of the two industrial rougher/scavenger circuits. Moreover, decreases in froth zone recovery significantly limit the overall cell recovery of valuable mineral achievable from the plant scavenger cells. However, the decrease in froth zone recovery could not be linked to the removal of frother from the pulp solution to the concentrate product in the preceding rougher flotation stages. Measurements of residual frother in solution suggested that, approximately, only 5–10% of the added frother was removed into the rougher/scavenger concentrate, with the remainder appearing in the scavenger tailings. This finding suggested there was apparently adequate frother in solution in the scavenger stages.There was, however, a correlation to the froth half-life, with the froth half-life also generally decreasing down-the-bank. A simple, empirical model, based on the froth half-life and froth residence time of gas, is proposed here to predict froth zone recovery. Further, it is proposed that the froth stability, as measured by the froth half-life, is strongly linked to the presence of particles in the froth, with poorly mineralised scavenger froth characterised by a short half-life and, potentially, a low froth zone recovery. The importance of particles on froth stability was confirmed in separately conducted laboratory experiments. These experiments also demonstrated the wide variation in froth stability behaviour between different frother types.     

浮选柱与730系列起泡剂适配研究及铜矿分选实践

旋流-静态微泡浮选柱在分选某些硫化矿时存在起泡剂起泡能力不足,进而导致浮选精矿回收率较低的问题。通过对730系列起泡剂在浮选柱应用中的气含率研究以及结合云南大红山铜矿的选矿实践对比研究,比较5种起泡剂的性能指标,综合精矿品位和回收率得出730C更适配于旋流-静态微泡浮选柱。