The use of amine complexes in managing inadvertent activation of pyroxene in a pentlandite-pyroxene flotation system

The major loss of base metals in beneficiation of the Merensky Reef ore occurs during the separation of the siliceous gangue from the platinum group and base metal sulphides by selective flotation. The paper examines the use of amine complexes in managing inadvertent activation of pyroxene in a pentlandite-pyroxene flotation system at pH 9. Zeta potential, time of flight secondary ion mass spectrometry and X-ray photoelectron spectroscopy data have shown that pyroxene becomes copper activated in the presence of copper sulphate. When xanthate ions are added to the copper activated mineral system, true flotation of pyroxene occurs. Furthermore, the flotation and surface analysis data revealed that pyroxene could also be inadvertently activated by Ni(II) ions, which would result in a higher pyroxene recovery and thus lower selectivity. In the presence of ethylenediamine (EDA) the concentration of copper(II) and nickel(II) ions found on pyroxene and pentlandite surfaces was significantly reduced, although the effect was significantly more predominant on pyroxene. The mechanism for the removal of the activating ions from the mineral surfaces involves the formation of soluble stable metal-EDA chelates, which are removed into solution.     

柿竹园矿区及周边农田土壤重金属形态分布与生物有效性研究

为了解柿竹园矿区及周边农田土壤重金属的生物有效性,采用连续提取法对该矿区及周边的农田土壤重金属Cu、Pb、Zn、Cd、As、Hg的形态分布和生物有效性进行了分析。结果表明:(1)柿竹园矿区及周边农田土壤未见Hg污染情况,但不同程度受到Cu、Pb、Zn、Cd、As的污染,尤以Cd、As污染为重;(2)柿竹园矿区及周边农田土壤中Cu、Pb、Zn以铁锰氧化物结合态为主,分别占其总量的48.3%、67.3%、47.1%,Cd铁锰氧化物结合态含量最高,残渣态、离子交换态和碳酸盐结合态次之;As和Hg以残渣态为主,含量比例在90%以上;(3)矿区及周边土壤中Cd的有效态含量最高,所占比例平均值为31.1%,远高于其他5种重金属元素,生物有效性最高,As的有效态含量最低,生物有效性最低。最后提出了采用稳定化修复技术清理污染源、采用磷酸二氢钙降低土壤中污染最严重元素Pb、Cd的生物有效性、采用香蒲等植物对工矿废弃地及部分未利用土地进行修复的建议。     

Use of organic polymers in the flotation of polymetallic ores: A review

Organic polymers are used in flotation for a wide range of oxides, silicates and industrial minerals as dispersants, depressants and as flocculants. Most of the investigations with polymers were conducted in this area and theories were advanced to explain the mode of adsorption on non-metallic mineral surfaces.In the area of sulphide flotation, polymers have found only limited application, although there is a great potential for the application of polymers in the selective separation of sulphide minerals. The use of polymers in sulphide flotation was not studied extensively and consequently, there are few reliable data available to explain the adsorption mechanism of polymers on sulphides.Published data on the use of polymers in flotation of sulphide minerals is reviewed in the following sections.     

Application of sugar foam to a pyrite-contaminated soil

Mining and mineral processing of sulphide ore deposits produce large quantities of wastes, most of which are characterised as toxic or hazardous, due to the formation of acid drainage, and to their heavy metal content.Samples of pyrite-contaminated soil from a former flotation plant were studied in this work to obtain environmental characterization and rehabilitation.Acid mine drainage prediction by the standard acid base accounting method (ABA) together with speciation techniques, were used in order to determine the potential pollution of the area.The effectiveness of sugar foam as an amendment in preventing acid drainage and metal dissolution was tested in this work.The application of sugar foam results in a neutralizing action, due to the contained calcium carbonate, and in pyrite oxidation inhibition, significantly reducing acid generation and metals release.     

地下煤火土壤典型重金属分布特征

通过采集乌鲁木齐大泉湖火区土壤样及实验室测定,研究了火区土壤理化性质与重金属Hg,As,Cu,Pb,Cr,Zn,Ni空间分布特征。结果表明:温度正常区土壤温度随采样深度增加的幅度较温度异常区小;温度正常、温度异常区土壤有机质含量随深度的增加均减少,温度正常区I,II,III,IV层土壤有机质含量大于温度异常区相应土层有机质含量;温度异常区土壤层I重金属Cu,Pb,Cr,Zn,Ni含量均小于温度正常区土壤层I相应重金属含量,II层则有增加的趋势并大于温度正常区相应土层重金属含量;温度正常区、温度异常区土壤Hg,As,Cu,Ni重金属含量随深度变化幅度及波动幅度较小,而温度异常区土壤Pb,Cr,Zn重金属含量随深度变化波动幅度较温度正常区大;火区热效应、地形、土壤及气象因子是影响土壤重金属分布的主要原因。土壤典型重金属砷形态分析表明:残留态砷含量最高,水溶态砷含量最低;水溶态砷在火区取样区域内I,II,III,IV土壤层区域富集特征与各层土壤碳酸钙富集特征趋于一致;温度正常区土壤残留态砷、铁形砷含量随深度变化的趋势与土壤碳酸钙含量随深度变化趋势一致;温度异常区残留态砷含量随深度增加波动趋势与土壤有机质含量波动趋势有较强关联性;温度正常区、温度异常区均值水溶态砷含量基本稳定,表明其与温度、土壤特性等无明显相关性。     

腐殖酸对污泥中重金属的稳定化研究

为分析腐殖酸对高重金属含量污泥的稳定化处理效果,采集某电镀厂污泥,以腐殖酸和高温改性腐殖酸为稳定剂,采用TCLP（美国环保局推荐的标准毒性浸出方法）分析腐殖酸和高温改性腐殖酸对污泥中重金属Cr、Cd、Zn和Pb的稳定化效果。结果表明：腐殖酸和高温改性腐殖酸的投加量分别为1 g和1.5 g,振荡时间为12 h,重金属的稳定化效果最好,浸出液中重金属的含量最低。重金属形态分析结果表明：加入腐殖酸和高温改性腐殖酸稳定后重金属主要以残渣态为主,不稳定态的含量较少。腐殖酸和高温改性腐殖酸的扫描电镜图片显示,高温改性腐殖酸具有细长针状结构,整体呈不规则的多孔结构。高温改性腐殖酸对电镀污泥中重金属的稳定化效果更好。     

金川矿区土壤重金属污染环境评价

金昌是我国重要的镍铜生产基地,然而矿山的开发活动对矿区及周围地区造成可很严重的土壤重金属污染。本文以金川矿区为主要调查区,测定了矿山及周边土壤的重金属含量,采用单因子污染指数、内梅罗指数、改进内梅罗指数和潜在生态风险指数4中评价方法对调查区进行重金属污染评价,结果表明调查区内二矿区及周边的铁路和工业厂区受到一定的污染,其他地区并未受到污染,矿山的开采和矿石的运输是造成调查区土壤重金属污染污染的主要原因。     

氧化铅锌矿物和含钙、镁、铁、硅矿物分离新方法——CF法研究

介绍了以新研制的氧化矿浮选的螯合型捕收剂CF为核心 ,以Pb(NO3) 2 为活化剂 ,水玻璃和六偏磷酸钠为方解石、白云石、石英、褐铁矿的选择性抑制剂的一种氧化铅锌矿物和脉石矿物浮选分离的新方法———CF法 ,并研究了该法浮选氧化铅锌矿物过程中各种因素的影响。单矿物及人工混合矿浮选试验结果表明 ,CF法在常温条件下的自然pH值矿浆中就能较好地实现氧化铅锌矿物和含钙、镁、铁、硅脉石矿物的浮选分离 ,并取得了良好的选别指标。CF法的最大特点是通过硝酸铅选择性地活化氧化铅锌矿物 ,降低CF的用量 ,且不需加温和预先用硫化钠硫化。     

铅锌选矿废水净化处理研究概述

重金属离子和残留浮选药剂是铅锌选矿废水的重要组成部分,未经处理的废水直接外排会污染环境,直接回用则影响选矿指标。不同的铅锌废水含有的重金属离子及选矿药剂的种类和量各不相同,需针对不同废水的性质及用途,采取针对性的废水处理办法对铅锌选矿废水加以处理,方可回用或外排,是环境保护、节约水资源的绿色矿厂的必然要求;本文主要介绍了铅锌废水的基本性质、来源、危害以及处理方法,对后期铅锌废水处理和发展具有一定的借鉴和促进作用。      

Hydrothermal sulfidation of zinc-containing neutralization sludge for zinc recovery and stabilization

The conventional lime-neutralization process generates a huge volume of neutralization sludge (NS). The disposal of NS is difficult because it contains large amounts of heavy metals, moisture and complex components. The present study describes the application of hydrothermal sulfidation (HS) toward the conversion of certain heavy metals (mainly zinc) in NS to metal sulfide (MeS) for subsequent metal recovery through flotation. The effects of temperature, time, sulfur concentration and liquid-to-solid ratios were investigated under laboratory conditions. The extent of zinc sulfidation was up to 85% under optimal conditions. Flotation tests indicated that the ZnS produced could be separated from the NS, increasing the recovered Zn concentration from 19.9% to 38.8%. The toxicity characteristic leaching procedure (TCLP) revealed that stabilization and detoxification of heavy metals occurred during sulfidation. The formation of metal sulfide by HS enhanced the stabilization effect. Moreover, flotation technology provided a means to enhance metal recovery from the NS.     

Removal of heavy metals from wastewater effluents by biosorptive flotation

The search for new technologies to remove hazardous metals from wastewaters has focused attention on the metal binding abilities of different biological materials. Various biomaterials have shown promise as sorbents to remove heavy metals from water. Several advantages of peat moss for such applications include its abundance, low cost, and high metal capacity. Consequently, the adsorption of heavy metals from aqueous solution was studied using a sphagnum peat moss. The adsorption process was found to be pH dependent, and the adsorption capacity increased with initial pH of the solution. The sorption equilibria could be expressed as Freundlich isotherms. The selectivity of the sphagnum peat moss for various heavy metal cations was Pb > Ni > Cu > Cd. The sorption behaviour of cations on the sphagnum peat moss was similar to that of cations on a gel type strong acid resin.Flotation was subsequently shown to be an effective solid-liquid separation process, avoiding the problem for the separation offine sponge-like moss flocs from the effluent by conventional filtration. A dispersed air flotation column was applied for the generation of fine bubbles to realise the solid-liquid separation. Biosorptive flotation may have practical applications for the removal of hazardous metals from contaminated water supplies.     

Influence of mineralogy and ore texture on pentlandite flotation at the Nkomati nickel mine,South Africa

The influence of ore mineralogy and ore texture on flotation response was studied for 29 samples from the main mineralised zone at Pit 3 of the Nkomati Ni mine, through laboratory scale flotation testing, laboratory assay, and mineral liberation analyser examination of the ore and the concentrates. The individual sample flotation responses vary widely in terms of Ni grade, and cumulative Ni recovery. It is demonstrated that this is a complex function of ore mineralogy and ore texture. Chalcopyrite is the first sulphide to float, followed by pentlandite and finally pyrrhotite, in ore samples with dominant chalcopyrite, or where pentlandite, pyrrhotite and chalcopyrite occur in equal abundance. However in samples with a high ratio of pyrrhotite to pentlandite and chalcopyrite, pyrrhotite floats earlier than expected, reports to concentrate over the entire flotation period, and depress and extend the flotation of pentlandite over the flotation interval with no clear peak of Ni recovery during flotation. Primary silicates (e.g. olivine and pyroxene) and alteration-related minerals (talc, tremolite and chlorite) are naturally floating, and hence affect the flotation of pentlandite in a similar manner to that of pyrrhotite. The most problematic ore at Nkomati in terms of Ni recovery is characterised by fine disseminated and fine bleb- or net-texture sulphides, contain abundant olivine, pyroxene, amphibole, talc and tremolite, and include abundant metamorphism-related country rock xenoliths (with calc-silicate minerals such as diopside and tremolite).     

Effect of ultrasonic preconditioning of pulp on the flotation of sulphide ores

The variables affecting flotation during ultrasonic preconditioning, i.e. pulp concentration, particle size and density, temperature, pressure, as well as ultrasound frequency and amplitude, were studied. An ultrasonic process for the batch flotation of sulphide ores from the Merensky reef in South Africa was designed to improve flotation performance, by selectively altering the surface properties of the target mineral particles. After ultrasonic excitation, the floatability of the sulphides improved significantly, and the silicates were also depressed to some extent. Compared to mechanical conditioning, ultrasonic radiation can improve the flotation rate, value grades and recoveries and reduce the dosages of flotation reagents appreciably.     

攀枝花矿区水系沉积物的组成及其环境效应

研究了攀枝花矿区水系沉积物的矿物成分、粒度组成特征,并用X射线荧光分析法分析了不同粒度样品中重金属的含量.结果表明:攀枝花市区水系沉积物以矿物集合体形式存在,其矿物组成以石英为主,粘土矿物次之,矿物含量基本为石英＞伊利石＞绿泥石＞方解石＞长石,另有少量白云石或钠闪石;细粒水系沉积物中的粘土矿物含量高于粗粒样品.沉积物呈不规则状,棱角明显,磨圆度差,主要为自然风化冲刷物,同时夹杂有人为的工业活动产物.由于粘土矿物有较强的吸附能力,因此重金属在细粒样品中的含量明显高于粗粒.     

Effect of mining chemicals on biosorption of Cu(II) by the non-living biomass of the macrophyte Potamogeton lucens

The present work investigates the effect of some compounds commonly discharged from mineral processing plants on biosorption of heavy metals by the non-living biomass of the freshwater macrophyte Potamogeton lucens. Studies of sorption of Cu (II) in the presence of metal ions, surfactants, EDTA and cyanide were carried out at laboratory scale. The results show that copper adsorption by ion exchange on the biomass is not affected by equimolar concentrations of copper/sodium, copper/calcium or copper/iron. Non ionic surfactants (e.g. pine oil) do not modify biosorption, but the negative groups of anionic surfactants (e.g. sodium oleate) compete with the surface groups of the biomass for the free copper ions in solution. EDTA and cyanide react with copper ions producing soluble complexes that do not adsorb onto the biomass. The biosorption process is suitable for wastewater treatment when the heavy metal species are free in solution. Effluents containing metal sequestering compounds that produce soluble or precipitated species are not able to be treated by carboxyl groups based biosorbents.     

云南思茅多金属硫化矿浮选试验研究

云南思茅石英脉多金属硫化矿,回收金属主要是Au、 Cu 、S,金铜矿物与黄铁矿紧密共生,嵌布粒度极细。为提高有用金属回收指标,对比了优先浮选与混合精矿再磨后分离浮选两种工艺流程,其中后者指标较好,铜精矿品位可达22.40%,回收率94.35%,为该矿的开发提供了可行的技术依据。     

云南新平铜尾矿库周边土壤重金属污染评价

大宗工业固体废物环境监管责任重大,对尾矿库周边土壤重金属污染现状进行评价是建立固体废物管理技术体系的重要内容之一。对云南新平县铜尾矿库周边土壤重金属污染特性和现状进行调查和评价。采用S型或梅花布点随机采样方式,评价标准参考国家土壤环境质量标准(GB 15618-1995)的要求,对尾矿库周边土壤采用土壤环境质量三级标准进行评价。运用单因子指数法和内梅罗综合污染指数法评价该地区,污染最小的元素为铜、汞和铅,污染最严重的元素为铬,且均属于非污染,尾矿库周边监测点土壤中各重金属元素均值污染程度属于安全范畴,污染水平属于清洁。但是运用潜在生态危害指数法评价,对于单个重金属的潜在生态危害系数,汞元素属于很强生态危害范畴,Ei值为166.21,其余各元素都属于轻微生态危害。对于各采样点,除1,2,3号点属于中等生态危害范畴,其余各点为轻微生态危害。对于总的潜在生态危害指数RI,该地区的RI值为207.39,达到中等生态危害。总体来说,云南新平铜尾矿库周边土壤被保护较好,符合国家土壤环境质量标准,个别样点存在潜在生态风险。因此,建议相关部门进一步监测,采取监测防治措施。     

The effects of electrical comminution on the mineral liberation and surface chemistry of a porphyry copper ore

The surface chemistry and mineral liberation changes of a porphyry copper ore after high voltage pulse (HVP) electrical comminution have been investigated using X-ray photoelectron spectroscopy (XPS) and mineral liberation analysis (MLA). Previous studies suggest that electrical comminution has the potential to improve downstream flotation recoveries, due to increased mineral liberation. However, until now the effects on the surface chemistry have not been investigated in detail.The mineral liberation results showed that chalcopyrite was more liberated in the electrical comminution product than in mechanical comminution, noticeably in the coarser size fractions. The surface chemistry of pure chalcopyrite was investigated, using XPS, and high resolution scans of iron and sulphur showed that both comminution methods led to iron oxidising preferentially leaving behind a passivating film of copper sulphides. However, the HVP product oxidisation was more severe with more iron oxide being produced and further oxidation of the remaining copper sulphides into copper sulphate. An attrition grinding stage may be useful in removing the oxidised layer from the surface of the particles prior to flotation separation. This paper presents a new application of the HVP technology in hybrid procedures using electrical comminution and mechanical grinding to prepare the flotation feed, rather than using excessive pulse energy to fully disintegrate ore to the flotation size. Better liberation and flotation performance were achieved through the hybrid procedures than the comparative mechanical comminution.     

煤矿复垦区土壤重金属含量时空分布及富集特征研究

为研究煤矿复垦区土壤重金属污染的时空变化及富集特征,以安徽淮南市潘一矿复垦区土壤为例,在2008-2010年期间对复垦区土壤中Cu,Mn,Ni,Pb,Cd,Hg,As 七种重金属元素进行了测定,并利用Surfer8.0软件对重金属的水平分布特征进行可视化表达。采用富集因子法来判断土壤中重金属人为污染情况。结果表明：煤矸石充填复垦区土壤,随着覆土年限的增加,除Mn和As元素外,Cu,Ni,Pb,Cd和Hg这5种重金属元素含量均高于淮南市土壤背景值,并出现一定程度的累积;从表层土壤重金属元素的水平空间分布看,煤矸石山的堆积、淋溶和粉煤灰贮灰场的存在对周边土壤造成了一定程度和范围的重金属污染。复垦区土壤剖面上Cu,Ni,Pb,Cd元素含量呈现表层（0~20 cm）和底层（80~100 cm）含量高,中部（20~80 cm）含量低的分布规律。分析重金属元素的富集因子,表明复垦区土壤已经受到了煤矿开采和煤矸石充填活动的影响。其中Cu,Ni,Pb,Hg和Cd元素已经出现富集,并且Cu,Ni,Pb,Hg元素达到了轻微污染水平,Cd元素达到了显著污染水平。Mn和As元素主要来源于土壤母质,没有受到污染。     

非金属天然矿物吸附材料在土壤重金属污染修复中的应用

随着土壤重金属污染日趋严重,非金属天然矿物吸附材料以其低价、无二次污染的独特优势,在土壤修复中得到应用。本文在介绍我国土壤重金属污染现状、天然矿物材料吸附性能的基础上,回顾了该类吸附材料的应用发展历程,着重突出了应用该吸附材料作为反应介质的渗透反应墙(PRB)、地球化学障(GB)技术,而水土一体化联合修复是一种较好的修复方式。对天然矿物吸附材料在土壤重金属污染修复中的应用研究提出了一些展望,包括吸附转化、影响条件、微观对比、多技术联合等。