The use of canola oil as an environmentally friendly flotation collector in sulphide mineral processing

The efficiency of mineral flotation relies on the ability to selectively recover different value minerals into their respective concentrates at optimum grades and recoveries based on the differing hydrophobicities. Many of the common hydrophobizing reagents (collectors) currently used in flotation have significant occupational and environmental implications, and hence there is a quest for environmentally benign chemical additives that give similar or better performance than the more toxic conventional reagents. In this paper, we provide substantial experimental evidence that the use of edible, fatty acid-based oils (canola and palm) can foster the flotation recovery of chalcopyrite and molybdenite minerals more selectively against pyrite than the conventional collectors, sodium isopropyl, potassium amyl xanthates and diesel oil.Single and mixed chalcopyrite/pyrite minerals and plant sulphide ores’ flotation studies using canola and palm oils, in contrast with conventional collectors, are reported herein. The results indicate greater efficacy of the canola and palm oils in comparison with the conventional collectors for chalcopyrite and molybdenite recoveries and product upgrades. This is believed to be due to the edible oils’ specific interactions with iron oxides sites preferentially formed in situ on the surfaces of the chalcopyrite or molybdenite in the pulp rather than on the pyrite surfaces, causing limited recovery of the pyrite. Complementary contact angle results confirmed that more canola oil is adsorbed onto chalcopyrite surfaces than onto pyrite surfaces. For the mineral mixtures tested, the edible oil’s degree of unsaturation had a noticeable effect on its performance as a collector. A higher pyrite recovery and slightly lower chalcopyrite grade was obtained with palm oil than with canola oil. These findings suggest that the use of canola oil has a potential to add to the existing array of flotation collectors and would represent a combined opportunity for both the mining and agricultural sectors, with concomitant health, environmental and economic benefits.     

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.     

The effect of acrylamide-co-vinylpyrrolidinone copolymer on the depression of talc in mixed nickel mineral flotation

Copolymers of acrylamide and vinylpyrrolidinone with varying compositions have been synthesised and employed to depress talc in a model flotation system with process plant operation conditions. Adsorption isotherms indicated that the hydrophilic acrylamide homopolymer has a very low affinity for the hydrophobic talc surface, whereas vinylpyrrolidinone homopolymer strongly adsorbs onto the talc surface. Micro-flotation experiments revealed that the copolymer system can induce stronger talc depression than the homopolymer variants, with the most effective copolymer depressant having 25-30% vinylpyrrolidinone incorporation. The copolymer system is observed to have inherited the strong talc affinity of vinylpyrrolidinone polymer and the strong hydrophilic property from polyacrylamide. This combined effect facilitates the desired strong talc depression in single mineral flotation. However, this copolymer system has similar adsorption affinity on both the talc and pentlandite, hence depressing both talc and pentlandite in the mixed mineral flotation system. This research shows that a sufficient hydrophobic balance on the polymer is necessary for the adsorption and subsequent depression for talc. However, polymer with high adsorption selectivity is required to be a successful synthetic talc depressant for mixed mineral system.     

铜离子和硫化矿作用机理的研究

本文通过浮选实验,ξ-电位和X-射线光电子能谱测定,研究了铜离子与闪锌矿和黄铁矿的作用机理。结果表明铜离子与硫化矿的作用与pH有关,在酸性介质中铜离子和硫化矿发生置换反应生成CuS,而在中性和碱性条件下,铜离子首先以羟合铜或氢氧化铜的形式在矿物表面迅速吸附或沉淀,然后这种羟合物再和硫化矿作用生成CuS。     

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.     

The effect of ionic strength of plant water on valuable mineral and gangue recovery in a platinum bearing ore from the Merensky reef

As the restrictions on water usage become more prevalent throughout the world, mining operations are required to understand the impact that water recycling will have on them. Not only owing to operational needs, but also from an environmental stand point. As would be expected recycling is likely to lead to increased dissolved ions, increasing the ionic strength, which may impact plant performance. By conducting flotation tests under varying degrees of ionic strength of synthetic plant water it is possible to better understand the effect that water recycling could have on the recovery of a mining operation. The effect of such an increase in ionic strength is discussed.     

难选铅锌硫化矿浮选新工艺的研究

通过研究某铅锌硫化矿石的分选条件与药剂制度, 提出了处理该类矿石的分选新工艺。生产实践证明, 新工艺不仅在精矿质量和回收率比原工艺有了显著提高, 而且药剂耗量也大幅度降低, 取得了显著的经济效益和社会效益。     

某低品位铅锌矿铅浮选工艺研究

某铅锌矿铅锌品位低、部分方铅矿与闪锌矿嵌布关系复杂,(含)银矿物种类多、可浮性参差不齐,给铅、银的回收带来困难。经过多方案比较,铅浮选采用\"阶段磨矿(原矿粗磨、铅粗精矿再磨)―阶段选别\"工艺进行选别,试验采用石灰+硫酸锌组合抑制黄铁矿和闪锌矿,乙硫氮和松醇油作铅捕收剂和起泡剂。对含Pb 2.22%、Zn 1.97%和Ag 13.25g/t的原矿,闭路试验可获得铅精矿含Pb 65.17%、Zn 3.63%,铅回收率为96.31%;铅精矿含Ag 305.95g/t,银回收率为75.92%;在强化铅选别的同时,有效实现了银的综合回收。     

The influence of the oxidation state of pyrite and arsenopyrite on the flotation of an auriferous sulphide ore

In this paper, the influence of the oxidation state of pyrite and arsenopyrite on the flotation of an auriferous sulphide ore was investigated by different techniques, including electrode, pulp potentials, DRIFT spectroscopy and microflotation tests. In addition, the gold and sulphide recoveries were also investigate, in a laboratory-scale cell, as a function of pulp potential and reagent concentration. It was verified that the presence of oxidation products on the sulphide mineral surface demands a higher collector concentration in order to achieve a satisfactory sulphide recovery. The electrochemical behaviour of pyrite and arsenopyrite indicated that a nitrogen atmosphere can lead to a low pulp potential, which inhibits the formation of oxidation products, enhancing both the free gold and sulphide recoveries. Although copper sulphate activates even oxidised sulphide surfaces, it does not improve free gold recovery.     

Distribution of Sb minerals in the Cu and Zn flotation of Rockliden massive sulphide ore in north-central Sweden

The Rockliden massive sulphide Zn–Cu deposit contains minor amounts of Sb minerals. The Sb mineralogy is complex in terms of composition, micro textures and mineral associations. The main Sb minerals comprise tetrahedrite, bournonite, gudmundite and Sb–Pb sulphides such as meneghinite. The presence of these minerals is especially critical to the quality of the Cu–Pb concentrate. To study how they are distributed in a simplified flotation circuit and what controls their process behaviour Sb-rich drill core samples were selected from the Rockliden deposit and a standard laboratory flotation test was run on the composite samples. Scanning electron microscope-based automated mineralogy was used to measure the Sb mineralogy of the test products, and the particle tracking technique was applied to mass balance the different liberation classes to finally trace the distribution of liberated and locked Sb minerals. The mineralogical factors controlling the distribution of Sb minerals are mineral grain size, the degree of liberation, and associated minerals. Similarities in the distribution of specific particle types from the tested composites point towards systematics in the behaviour of particles and predictability of their distribution which is suggested to be used in a geometallurgical model of the deposit.     

会泽铅锌硫化矿浮游性评价新方法

采用分批刮泡浮选试验方法,根据模糊数学中的隶属度和隶属函数,提出从可浮性和浮游速度两个方面综合评价矿物浮游性的新方法,实现了矿物浮游性的量化。应用新方法分析了会泽方铅矿、闪锌矿和黄铁矿在矿浆pH值为7.5,乙基钾黄药浓度为2.0×10-4 mol/L,硫酸锌浓度为1.5×10-4 mol/L条件下的浮游性,结果表明3种矿物的浮游性依次是方铅矿>黄铁矿>>闪锌矿,这与浮选工业实践中的结果相符合。     

贵州某硫化锑矿选矿实验研究

针对贵州某硫化锑矿矿石性脆易碎、赋存状态复杂、锑矿物嵌布粒度粗细不均且存在局部氧化的特点,对硫化锑矿的活化剂和捕收剂等进行了实验.结果表明,采用丁黄药+丁铵黑药组合捕收剂及PCA活化剂回收锑,在给矿锑品位为5.66％的情况下,获得锑精矿Sb品位57.02％、Sb回收率93.07％的指标.     

调浆过程能量输入对微细粒白钨浮选矿浆流变特性的影响研究

采用矿浆流变性测试与浮选试验,研究了微细粒白钨矿浮选体系中微细粒白钨矿、方解石、石英及其人工混合矿矿浆流变性、浮选行为与调浆过程能量输入之间的关联机制。结果表明,微细粒白钨矿与方解石矿浆表观粘度高、屈服应力大、聚团程度较严重,造成混合矿具有较大的表观粘度与屈服应力。通过搅拌调浆过程能量输入调控,能够显著提升浮选过程选择性。     

能带理论及其在选矿中的研究现状

论述了能带理论的主要内容及其常用的计算方法,并介绍了能带理论在选矿中应用进展,包括黄药与硫化矿物的作用机理、半导体矿物-溶液界面的电子能级分布模型、电化学调控浮选模型、细菌对硫化矿氧化浸出的影响等。     

Rheological behaviour of lateritic smectite ore slurries

The characterisation and rheology of several nickel laterite smectite ores and pure minerals are compared to assess the effect of mineralogy and particle size on the viscosity of high pulp density slurries. A vane viscometer was used to determine the “optimum pulp density” (OPD) that gave a yield stress of 100 Pa which is considered to be optimal for pumping slurries into autoclaves in the HPAL process. In general, slurries containing finer particles were more viscous and smectite slurries exhibited poor rheological behaviour as compared to slurries of goethite < kaolin < talc < hematite < maghemite < magnesite. Blending the smectite ores with a fraction of the pure minerals improved the rheological behaviour of the pulp and can increase the optimum pulp density of the smectite blend by over 5% w/w.When the physical properties of the smectite ore and slurry were examined, a very good linear correlation was obtained between the optimum pulp density and the settling density which provides a simple measure of predicting rheological behaviour of slurries. The variation in the viscosity of the nickel laterite ores depends largely on their mineralogy and particle size distribution. The mean particle size and P₈₀ values of various smectite ores containing the same mineral phases were also found to have a reasonably good linear correlation with OPD in saline water, but the correlation of ore surface area with OPD was a poorer fit.     

低硫铅锌矿选矿工艺的研究

某硫化铅锌矿含铅8.79%,含锌13.24%,采用一段磨矿（细度73％－0.075mm）、选浮铅、中矿循序返回的优元宵服选流程及混合捕收剂乙、丁黄药和SN－9,得到：铅精矿品位71.55%,回收率91.89%;锌精矿品位50.34%,回收率85.38%,并综合回收了伴生的镉、银。     

硫化矿活化剂FY01的制备及应用研究

通过小型试验合成得到高效硫化矿活化剂FY01,FY01弱酸性、腐蚀性小,在多金属硫化矿浮选中,取代腐蚀性大的硫酸活化目的矿物,试验指标与使用硫酸时相近。     

青海某铜锌硫化矿选矿试验研究

摘要:针对青海某铜锌硫化矿石开展试验研究,矿石性质研究表明,该矿铜矿物嵌布粗细不均匀,大约有15%的铜矿物呈微细粒（粒度小于10μm）包裹于脉石矿物中,难以得到有效回收,同时原矿含锌较低,含量在锌矿边界品位（0.5～1%）,可考虑伴生回收。针对该矿矿石性质,采用优先浮铜工艺,可有效实现铜、锌分离,获得了铜精矿品位18.66%、铜回收率83.90%、铜精矿含金3.06g/t,锌精矿品位41.69%、锌回收率29.49%的较好选矿指标。      

细粒矿物浮选研究进展

概述了细粒矿物对浮选影响的研究进展,包括细粒矿物的浮选回收、细粒对浮选的影响机制以及细粒矿物对粗粒矿物浮选的影响,为细粒矿物浮选的研究提供一定的参考。