蛇纹石对黄铁矿浮选的影响及机理

通过浮选实验、沉降实验、显微镜下观测、接触角测试和吸附量实验,研究蛇纹石对黄铁矿浮选的影响,并对其机理进行分析。结果表明：矿物粒度在蛇纹石与黄铁矿的浮选分离中起着重要作用,比黄铁矿粒度小的蛇纹石颗粒能够通过异相凝聚作用吸附在黄铁矿表面,改变黄铁矿的表面性质,影响黄铁矿的浮选。机理研究表明：蛇纹石表面是亲水的且不吸附捕收剂戊黄药(PAX)。蛇纹石吸附在黄铁矿表面,降低了黄铁矿表面疏水性和戊黄药在黄铁矿表面的吸附量,使黄铁矿浮选回收率降低。增加戊黄药在黄铁矿表面的吸附量能够一定程度上恢复被抑制黄铁矿的浮选回收率,但蛇纹石用量较高时,黄铁矿浮选回收率仍降低。因此,微细粒蛇纹石通过异相凝聚作用在黄铁矿表面附着,降低黄铁矿表面疏水性是蛇纹石影响黄铁矿浮选的主要原因。     

煤系黄铁矿晶格缺陷与可浮性机理研究

为脱除煤中的黄铁矿,分析煤系黄铁矿中碳质的存在形式及其与可浮性的关系机理具有重要的意义。以中国典型矿区的矿系黄铁矿和煤系黄铁矿为研究对象,采用先进仪器分析手段,对矿系黄铁矿和煤系黄铁矿的元素组成、矿物构成及表面性质进行系统分析。研究发现煤系黄铁矿表面存在碳元素掺杂。在此基础上,采用密度泛函理论(DFT)平面波赝势方法模拟了碳元素对煤系黄铁矿表面性质的影响规律,并进行了接触角的测量及浮选试验。模拟计算结果表明：含碳掺杂缺陷的煤系黄铁矿表面亲水性减弱、可浮性增强,在煤泥浮选过程中更易上浮,接触角的测量及浮选试验结果与模拟结果吻合。从量子化学的角度揭示了煤系黄铁矿晶格缺陷与可浮性关系的机理。     

FeSO4取代H2SO4选别黄铁矿的研究

研究了用FeSO4取代H2SO4作调整剂从浮选铅锌的尾矿中回收黄铁矿的可能性,将FeSO4加入到浮选铅锌的尾矿中,使受抑制的黄铁矿恢复可浮性,试验表明,当FeSO4用量为15－18kg/t时,矿浆pH由12.8降到8左右,用乙黄药作捕收剂,可获得的硫精矿品位47.26%,回收率87.88%,该指标与用H2SO4的选别指标相近。     

调浆气氛对黄铁矿浮选电化学性质影响研究

基于氧气在黄铁矿浮选电化学反应中的作用,考察了p H为4.00、6.86、9.18、10.01和10.96五种缓冲溶液浮选体系下,矿浆溶氧量(DO)对黄铁矿浮选矿浆电位(Eh)和回收率的影响。研究表明,五种缓冲溶液体系下,Eh均随着DO的增加而增加,碱性条件下DO对Eh的影响较小;浮选回收率随DO的增加呈下降趋势,碱性条件下回收率的变化较大。     

Application of complexing reagents to flotation separation of the varieties of pyrite

It is considered how the organic reagents, complexing agents, change floatability of the varieties of pyrite with different content of goal. The authors continue studying the flotation effect of the reagent PROX capable to selectively decrease floatability of some pyrite varieties in the presence of xanthogenate due to formation of a hydrophilic complex compound with ferric iron at the phase interface of the mineral surface — liquid, and to reduce sorption of xanthogenate. A phytogenous reagent is suggested as an alternative to the multi-component PROX. The new reagent mechanism is described by examining the chromatographic behavior of the compound of this reagent and ferric iron salt. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 4, pp. 111–120, July–August, 2007.     

Formation of hydrogen peroxide by pyrite and its influence on flotation

Formation of hydrogen peroxide (H₂O₂), an oxidising agent stronger than oxygen, by pyrite (FeS₂), the most abundant metal sulphide on Earth, during grinding was investigated. It was found that pyrite generated H₂O₂ in pulp liquid during wet grinding and also the solids when placed in water immediately after dry grinding. Type of grinding medium on formation of hydrogen peroxide revealed that the mild steel produced more H₂O₂ than stainless steel grinding medium, where Fe²⁺ and/or Fe³⁺ ions played a key role in producing higher amounts of H₂O₂. The effect of grinding atmosphere of air and N₂ gas showed that nitrogen environment free from oxygen generated more H₂O₂ than air atmosphere suggesting that the oxygen in hydrogen peroxide is derived from water molecules. In addition, the solids after dry grinding producing more H₂O₂ than wet grinding indicate the role of pyrite surface or its catalytic activity in producing H₂O₂ from water. This study highlights the necessity of relooking into the electrochemical and/or galvanic interaction mechanisms between the grinding medium and pyrite in terms of its flotation behaviour.     

用分步浮选从高品位黄铁矿中浮选清洁硫精矿研究

从禀赋较好的黄铁矿石中用选矿新工艺-分步浮选法,浮选清洁硫精矿具有许多优点,它与常规浮选法相比较,可以简化工艺流程,节省硫酸用量,降低生产能耗,产出含硫品位48%的清洁硫精矿。该精矿经沸腾炉焙烧后其烧渣铁品位61%,含硫量0.3%,可直接作为炼铁的原料,从而使黄铁矿烧渣综合利用问题得以解决。     

The separation of chalcopyrite and chalcocite from pyrite in cleaner flotation after regrinding

In this study, the differences between the separation of chalcopyrite and chalcocite from pyrite in cleaner flotation after regrinding were investigated. In the rougher flotation prior to regrinding, high chalcopyrite and chalcocite recovery were obtained in conjunction with high pyrite flotation recovery due to the activation of pyrite by copper ions during primary grinding. The rougher flotation concentrate was reground in a rod mill before cleaner flotation. It was found that chalcopyrite and chalcocite exhibited different flotation behavior and also affected pyrite flotation differently in cleaner flotation. The mechanism underpinning these phenomena was investigated by a range of techniques including the polarization of mineral electrodes, X-ray photoelectron spectroscopy (XPS) analyses and ethylene diamine tetraacetic acid (EDTA) extraction. It was found that the flotation behavior of both copper minerals and their effect on pyrite flotation after regrinding were governed by their electrochemical activities and galvanic coupling with pyrite.     

磨矿介质对长石和石英浮选行为的影响及机理分析

研究了长石和石英在湿式磨矿条件下,分别选用十二胺和油酸钠作为捕收剂,锆球和铁球作为磨矿介质时的浮选行为;并通过检测矿浆中典型金属离子浓度和矿物动电位,借助于矿物表面X-射线光电子能谱(XPS)检测,剖析磨矿介质对矿物浮选影响的机理。研究表明,采用十二胺作为捕收剂时,无论是铁球湿磨还是锆球湿磨,长石的回收率都高于石英;采用油酸钠作为捕收剂时,锆球湿磨长石和石英均不浮,铁球湿磨长石和石英的可浮性存在一定差异。矿浆中典型金属离子浓度、矿物动电位和矿物表面XPS的检测结果表明,锆球湿磨长石和石英矿浆中金属离子浓度高,不利于阴离子捕收剂浮选;铁球湿磨时,长石和石英零电点对应的p H值比锆球湿磨高,在两种矿物表面均检测出铁的羟基络合物,这不利于阳离子捕收剂浮选,而有利于阴离子捕收剂浮选。     

Ca(ClO)2与腐殖酸钠对黄铜矿和黄铁矿浮选的影响

纯矿物试验和人工混合矿试验表明,Ca（ClO）2与腐殖酸钠都对黄铁矿具有很好的抑制作用,而不抑制黄铜矿,二者组合使用能更加有效抑制黄铁矿.根据杨氏方程结合接触角的测定结果,计算矿物表面润湿能,结果说明腐殖酸钠和Ca（ClO）2组合抑制剂对黄铁矿的良好的抑制性能,是二者协同作用的结果.     

铁介质磨矿对锂辉石和绿柱石浮选影响的分子模拟计算研究

利用分子模拟计算方法,研究了铁球作为磨矿介质,十二胺和油酸钠分别作为捕收剂,锂辉石和绿柱石与捕收剂在磨矿前后的相互作用能。结果表明,这两种典型硅酸盐矿物经过铁球磨矿后,矿物表面吸附的铁,使阳离子捕收剂十二胺与矿物的相互作用能增大,阴离子捕收剂油酸钠与矿物的相互作用能减小,进而影响捕收剂与矿物之间的相互作用。总体来讲,锂辉石和绿柱石经过铁球磨矿后,一般会阻止十二胺阳离子捕收剂在矿物表面的吸附,而对于油酸根阴离子捕收剂,则起到一定的活化作用,有利于油酸根离子在矿物表面的吸附。     

石英与蛇纹石异相凝聚及其对黄铁矿浮选的影响

通过单矿物和人工混合矿的浮选试验、Zeta电位测试、吸附量测试,研究了蛇纹石和石英异相凝聚的机理,以及对黄铁矿浮选的影响,以进一步探索多种矿物的体系中,蛇纹石对硫化矿物浮选影响的主要原因。结果表明:通过添加石英,可以恢复黄铁矿对捕收剂的吸附量,减弱蛇纹石的不良影响,不同粒级的石英与蛇纹石的异相凝聚作用强弱不同,粒级越细的石英,与蛇纹石的异相凝聚作用越强。     

GF组合药剂浮选柿竹园多金属矿萤石的研究

针对柿竹园矿矿石性质复杂,萤石品位低,嵌布粒度细,共生关系复杂,研制出能有效分散泥化絮团和强烈抑制易浮微细粒脉石的组合药剂GF,采用粗精矿再磨、中矿集中再选及强磁脱硅工艺,从浮钨尾矿回收萤石,获萤石精矿品位98.47%,回收率71.19%。     

The effect of temperature on the pulp and froth phases in the flotation of pyrite

The effect of temperature on the flotation of pyrite has been investigated. At temperatures below ambient an increase in temperature results in an increase in the rate of flotation of fast-floating particles but has a minimal effect on that for slow-floating particles. At temperatures greater than ambient the dominant effect of increasing temperature is to decrease the viscosity of the water thus increasing the rate of elutriation of the gangue back to the pulp. In general an increase in temperature resulted in an increase in the rate of pyrite recovery and the sulphur grades and a decrease in the water recovery and size of the bubbles in the pulp.     

炼焦中煤磨矿浮选试验研究

以屯兰矿选煤厂-3mm粒级重介质分选中煤为试验煤样,采用MiniFlex600 X射线粉末衍射仪和OLYMPUS BX51显微镜研究了煤样的矿物组成与嵌布特征,并对磨矿后的产品进行了浮选试验。结果表明:-0.074mm 粒级含量为67.32%时,在捕收剂用量200g/t和起泡剂用量50g/t的条件下,通过一粗一精浮选可回收产率为34.75%,灰分为11.64%的合格精煤。      

从金宝山铂钯浮选尾矿中再回收铂钯的研究

根据金宝山铂钯浮选尾矿的矿石性质，采用磁选－磨矿－浮选工艺能有效地回收铂钯。在铂钯浮选中用丁黄药和丁胺黑药作联合捕收剂，用L101作微细脉石抑制剂，选别效果理想。在给矿品位为Pt0．216g/t和Pd0.603g/t时，获得精矿品位为Pt16.540g/t和Pd19.530g/t， 回收率为Pt41.64%和Pd23.37%.     

On the mechanism of the flotation of oxides and silicates

The mechanism of flotation of oxide and silicate minerals was established long ago as being due to the electrostatic attraction between the charged surface and the charge of the collector. What is less well established is the mechanism of the charging of the mineral surface. Most researchers have postulated that the adsorption of H⁺ is the cause. However, the adsorption model and its derivatives (such as the amphoteric and multisite-adsorption models), do not successfully describe the data for the zeta potential as a function of pH. In particular, these adsorption models have the following features that are not observed: (i) they are symmetrical about the point of zero charge, whereas the data is asymmetrical, (ii) they have an inflection at the pK_a values, leading to an asymptotic approach to the point of zero charge, whereas such an inflection is not observed, and (iii) they only fit the data in its extremes, that is, when the pK_a values differ by orders of magnitude, or are very close to one another. An alternative mechanism of charging is proposed here that is based on the dissolution of ions from and deposition of ions onto the mineral surface. It is shown that this model (a) fits the data, (b) is consistent with the thermodynamic model for reversible interfaces, (c) is consistent with the thermodynamics of the overall reaction and its solubility, (d) indicates reasons for the ageing of surfaces and (e) displays the observed features of zeta potential measurements as a function of pH, that is, it is pseudo-Nernstian and asymmetrical in nature. Application of the proposed theory is discussed for the flotation of quartz and corundum.     

Effects of free cyanide and cuprous cyanide on the flotation of gold and silver bearing pyrite

At gold and silver mineral processing plants, cyanide species are always present in the process water recycled to flotation circuits, despite the cyanide destruction process. The effect of cyanide, in particular, cuprous cyanide on gold and silver flotation has not been well understood. In the present study, free cyanide and cuprous cyanide species were isolated and their effects on the flotation of a pyritic ore were evaluated. It was found that free cyanide depressed gold and silver flotation through their carrier, pyrite. Cuprous cyanide mainly in the form of Cu(CN)₃²⁻ depressed pyrite flotation similarly as free cyanide. Electrochemical studies including open circuit potential (OCP), cyclic voltammetry and electrochemical impedance spectroscopy (EIS) techniques were carried out to understand the underpinning depression mechanism of cyanide species on pyrite flotation using xanthate as collector. It was found that all surface electrochemical reactions were inhibited by either free cyanide or cuprous cyanide. The surface layer as a result of xanthate adsorption on pyrite was completely removed in the presence of these cyanide species, which was suggested to contribute to the hydrophilic pyrite surface.     

Electrochemical characteristics and collectorless flotation behavior of galena: With and without the presence of pyrite

The electrochemical characteristics, surface properties and collectorless flotation behavior of galena with and without the presence of pyrite have been studied. Electrochemical tests confirmed previous reports in the literature that galena is electrochemically more active than pyrite and serves as the anode in galvanic combinations with pyrite. Cyclic voltammograms and polarization curves tests indicated that the addition of pyrite did not change the oxidative and reductive products of galena, but increased the current density during oxidation process. Zeta potential of galena showed a significant difference when coupled with pyrite, due to the influence on the oxidation of the mineral surface. Flotation results showed that the presence of pyrite leading to an influence on the collectorless floatability of galena and the influence correlation with the composition proportion of each mineral.     

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.