Surface characterisation,collector adsorption and flotation response of enargite in a redox potential controlled environment

We previously investigated oxidation of the surface of natural enargite (Cu₃AsS₄) under potentiostatic control and the formation of oxidation species at the mineral surface at selected applied potentials in the oxidative range. Here we further extended the research by incorporating flotation collectors into the system. Electrochemical techniques, X-ray photoelectron spectroscopy (XPS) and microflotation in a redox potential controlled environment were applied to examine surface properties, collector adsorption and flotation response of enargite in pH 10 solutions of sodium ethyl xanthate (SEX) and sodium dialkyl dithiophosphinate (3418A). The spectral details of XPS analysis of electrochemically treated enargite surfaces show significant adsorption of SEX and 3418A collectors onto enargite at an applied voltage of +516 mV, but no adsorption of both collectors at −400 mV. The results of XPS analysis agree with the floatability of enargite determined by microflotation, showing that the flotation recovery was highest at high oxidative potential (+516 mV), then decreased at low oxidative potential (+100 mV) and was very poor at −400 mV. These results confirm that enargite floatability can be efficiently controlled electrochemically.     

Evaluation of flotation technology for the trona industry

Trona ore consists mainly of trona, sodium sesquicarbonate dihydrate (Na₂CO₃·NaHCO₃·2H₂O), including minor undesirable insoluble materials. With the present industrial practice, there is no particle separation process to remove these insoluble minerals prior to thermochemical processing. In this current research appropriate conditions for trona flotation technology were established from exploratory bench-scale experiments, and the conditions obtained from the bench-scale experiments were also applied to pilot scale flotation tests. In this regard various process variables such as amine dosage, flotation percent solids, amine to oil ratio, pH of amine solution, collector structure, brine composition, feed particle size, etc. were studied to establish the preferred conditions and operating variables for pilot-plant testing. Additional information regarding the mineralogy of the system and collector characteristics is also reported to provide further analysis and explanation.     

The flotation chemistry of potassium double salts: Schoenite,kainite, and carnallite

It is known from soluble salt flotation practice that the K, Mg double salts of kainite (KClMgSO₄3H₂O), and carnallite (KClMgCl₂6H₂O) are difficult to float and must be converted to other salts such as schoenite (K₂SO₄MgSO₄6H₂O) and sylvite (KCl) in order to recover potash values. The flotation characteristics of these double salts have now been confirmed in some detail by carefully controlled laboratory experiments with both cationic and anionic collectors. The experimental results are discussed in view of recent experimental findings regarding the flotation characteristics of simple salts, in which the flotation response was shown to be determined by the interfacial water structure and whether the salt could be considered to be a water structure maker or a water structure breaker. The same approach can be use to explain the flotation response of the potassium double salts; schoenite, kainite, and carnallite.In addition, the sign of the surface charge of schoenite (K₂SO₄MgSO₄6H₂O), was determined as a function of pH from nonequilibrium electrophoretic mobility measurements. Schoenite appears to exhibit three charge reversals (CR) which can be explained based on surface hydrolysis reactions. The flotation behavior of schoenite is further considered based on solution chemistry calculations, electrophoretic mobility measurements, and microflotation results.     

硫砷铜矿、蓝辉铜矿与铜蓝表面选择性氧化浮选分离研究

针对蓝辉铜矿、铜蓝和硫砷铜矿开展了表面选择性氧化浮选分离研究,并通过矿物表面接触角变化及XPS表面分析,阐明了3种矿物表面选择性氧化反应机制。结果显示,氧化剂次氯酸钙和高锰酸钾均可有效抑制蓝辉铜矿和铜蓝上浮,但对硫砷铜矿可浮性无影响; 在丁铵黑药作用下,硫砷铜矿和蓝辉铜矿接触角均达到90°,经次氯酸钙氧化后,蓝辉铜矿接触角降至15°~30°,硫砷铜矿接触角仍高于86°; XPS分析结果表明,次氯酸促进了蓝辉铜矿表面的氧化,硫元素被氧化为SO₄^2-,以CuSO4形式覆盖在矿物表面,增加了表面亲水性,而硫砷铜矿表面As、Cu和S元素并未发生明显的氧化反应,矿物表面维持较高的疏水性。次氯酸钙实现了蓝辉铜矿与硫砷铜矿表面选择性氧化,强化了两者的浮选分离。     

Flotation separation of copper sulphides from arsenic minerals at Rosebery copper concentrator

The removal of arsenic bearing minerals from concentrates is becoming more important as environmental laws become ever stricter with regard to smelter emissions. The onus is shifting to concentrate producers to remove these minerals from their product, with penalties applying to materials containing greater than background amounts.The arsenic content of Rosebery copper flotation feed is mainly present as arsenopyrite (FeAsS), containing approximately 46.0% arsenic with the remainder of the arsenic in copper sulphosalts (tennantite (Cu₁₂As₄S₁₃)), in a solid solution series with tetrahedrite (Cu₁₂Sb₄S₁₃). Tennantite contains approximately 20.3% arsenic. Characterisation of the rougher and cleaner concentrates obtained during a plant survey showed that the arsenopyrite was appropriately rejected in the copper flotation circuit. However, tennantite showed similar flotation behaviour to the copper sulphide minerals so that the high arsenic content of the final copper concentrate was mainly in the copper sulphosalts. In this study, regrinding the copper rougher concentrate was investigated to reject tennantite in cleaner flotation. It was found that although finer grinding increased the mass fraction in the ultrafine fraction, the tennantite liberation only increased slightly. The copper selectivity against arsenic was improved significantly although the recovery of copper, silver and arsenic was lower. The difference in floatability of copper sulphide minerals and tennantite appears to increase at finer sizes. In this study, pH and Eh were also manipulated to further improve the selectivity of copper flotation against tennantite at fine particle sizes with some promise. In order to find an application in the Rosebery circuit, any changes must have a net economic benefit and the trade-offs and implications are discussed in this paper.     

Upgrading of a chalcopyrite concentrate by reaction with copper(II) and sulfite – Unexpected formation of Chevreul’s salt,Cu2SO3·CuSO3·2H2O

Recovery of aqueous copper(II) onto a chalcopyrite concentrate was shown to be rapid at 60 °C in the presence of S(IV), in this case sulfite. Surprisingly, rather than partial conversion of chalcopyrite to a copper sulfide such as chalcocite or covellite, copper was removed from solution by precipitation of a mixed-valence copper sulfite, Chevreul’s salt (Cu₂SO₃·CuSO₃·2H₂O). This has application as a way to increase the copper grade of chalcopyrite concentrates using the leachate from a Galvanox? leach of flotation tailings, offering several advantages over similar processes employing an autoclave to effect copper precipitation.     

某含砷铜精矿铜砷分离选矿试验研究

以蓝辉铜矿和硫砷铜矿为主的浮选铜精矿,为了产品效益最大化,进行浮选分离获得高砷铜精矿和低砷铜精矿.蓝辉铜矿和硫砷铜矿纯矿物试验结果表明,在捕收剂丁铵黑药体系下,采用石灰调整矿浆pH值,分别添加次氯酸钙、高锰酸钾、腐殖酸钠以及木质素来抑制蓝辉铜矿,均可以起到很好的抑制作用,但不同的药剂在不同的矿浆pH值条件下抑制效果不同...     

低碱下氯化氨抑制铜活化黄铁矿浮选机理研究

通过单泡浮选、吸附量测定、X射线光电子能谱(XPS)分析以及溶液化学计算研究了低碱环境下氯化铵抑制黄铁矿硫酸铜活化浮选的机理。单矿物和混合矿浮选结果表明,低碱条件下氯化铵能够有效抑制黄铁矿的铜活化浮选、提高锌硫分离效果。黄铁矿表面产物分析以及溶液化学计算结果表明,氯化铵抑制黄铁矿的铜活化浮选主要通过以下两个途径实现:在低碱性环境下,加入氯化铵后产生的酸碱缓冲对NH3-NH4+能够维持体系pH值,从而维持黄铁矿表面的羟基化程度,使黄铁矿被亲水抑制;NH3(aq)与Cu2+发生配合反应生成铜氨配合物的趋势很大,其能够与黄铁矿表面竞争消耗铜离子,削弱黄铁矿表面的铜离子吸附活化过程。为实现低碱锌硫浮选分离工艺提供了新思路,为在工业中实现低碱锌硫分离工艺奠定了理论基础。     

Process mineralogy of fluorosilicate minerals in ok tedi ores

The impact of fluorine in copper flotation was relatively unknown until the introduction of skarn ores in the Ok Tedi concentrator. Fluorine in the copper concentrates reports to the gas phase during the smelting stage and forms a corrosive H₂SO₄-HCl-HF acid brine mixture which must be neutralised.This work was aimed at studying the mineralogy of the fluorosilicate minerals contained in the various oretypes present in the Ok Tedi porphyry copper deposit. The electron microprobe was used to analyse for fluorine and hence identify the fluorosilicate minerals in each oretype. This study revealed talc, phlogopite, biotite, clays, amphiboles, fluoroapatite and titanite to be the sources of fluorine in the orebody.Laboratory and plant investigations were conducted to study the flotation response of these minerals. Chemical assaying of the products of these tests was done to determine the bulk assay of fluorine. Using Rietveld analysis, quantitative estimates of the fluorosilicate minerals in these products were generated. Marrying of the bulk assay with the respective mineralogical “assay” enabled the understanding of the flotation behavior of fluorine and it's associated mineralogy. Talc and phlogopite were found to be the causes of the fluorine problem at Ok Tedi.     

Interaction of sodium diisobutyl dithiophosphinate and platinum in aqueous solutions and on sulphide surface

For the noble metal flotation reagents, the authors propose a new test method of selective adsorption on surface of minerals covered with noble metal grains, by using a scanning electron microscope equipped with an X-ray energy-dispersive microanalyzer. Sorption of DTPINa was recorded by SEM and thin layer chromatography on surface of platinum metal grains in the form of a compound identical to the synthesized compound Pt[(iso-C₄H₉)2PS₂]₂. It has been found that interaction of DTPI and platinum ions can run in unheated aqueous solutions at a rate sufficient for flotation. In pH 4–9 range, the rate of platinum DTPI formation is maximal. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 75–84, March–April, 2009.     

影响典型铜矿物可浮性的晶体化学基因研究

为实现“基因矿物加工”系统工程建设,探究基因特征与铜矿浮选的关系,以具有代表性的铜矿物黄铜矿、斑铜矿、孔雀石、蓝铜矿和赤铜矿作为研究对象,通过 XPS、溶解性试验、Zeta 电位、接触角等测试分析及 MS 模拟计算等分析总结了含铜矿物的基因特征。通过浮选试验得到了含铜矿物的天然可浮性为：斑铜矿>黄铜矿> 赤铜矿>孔雀石>蓝铜矿;在乙基钠黄药（NaEX）、丁基钠黄药（NaBX）、异戊基黄药（NaIAX）和丁铵黑药体系下的浮选规律为黄铜矿、斑铜矿有较好的可浮性,而孔雀石、蓝铜矿和赤铜矿的可浮性较差,可浮性优异大致规律为：斑铜矿>黄铜矿>蓝铜矿≈孔雀石>赤铜矿;结合基因特征分析得出含铜矿物的天然可浮性规律与断裂面、断裂键密度和断裂键等基因特征有关,而在 NaEX、NaBX、NaIAX 和丁铵黑药体系下铜矿物的可浮性规律与铜矿物的禁带宽度和表面 S 元素含量基因特征有关。     

铜铅混合精矿硫酸预氧化-浮选分离参数优化试验研究

方铅矿与黄铜矿的分离一直是选矿领域的难点。使用硫酸预氧化可选择性抑制方铅矿表面可浮性,使得两种矿物可浮性产生差异,实现浮选分离。本研究针对铜铅混合精矿硫酸预氧化-浮选分离工艺进行了系统的参数优化。首先,利用单因素试验,分析了预氧化硫酸浓度、温度、时间等关键因素对铜铅混合精矿浮选分离效果的影响;其次,利用正交试验分析,建立了预氧化过程中各影响因素与浮选指标之间的数学模型;通过模型求解,得到最佳预氧化条件为硫酸浓度5 mol/L、时间40 min 、温度100 ℃。最后在上述条件下进行了混合精矿预氧化-浮选闭路试验,获得了铜精矿Cu品位18.03%,Cu回收率94.52%;铅精矿Pb品位47.12%,Pb回收率为91.29%的良好指标,铜铅分离效果显著,对铜铅硫化混合精矿的浮选高效分离提供了一定的借鉴。     

某低品位金铜矿石浮选柱应用试验研究

某低品位金铜矿石含铜0.46%、金0.18 g/t,矿石中铜矿物主要以蓝辉铜矿、辉铜矿、铜蓝、硫砷铜矿等次生铜矿物存在,其可浮性好但容易过磨,造成浮选时细粒级损失较高,试验采用浮选柱+浮选机联合选别与单独采用浮选机相比,其它指标相当的情况下,铜精矿品位提高9.6%,硫精矿回收率提高9.23%,试验表明浮选柱对提高精矿品质、简化流程和强化细粒级回收方面具有较为明显地优势。     

Pulp potential and floatability of chalcopyrite

Contact angle measurements, ultraviolet (UV) spectroscopy and microflotation studies were carried out in order to investigate the effect of externally applied potential on the wettability of both synthetic and natural chalcopyrites in potassium amyl xanthate (PAX) solutions. The contact angle on the mineral electrode surface was measured after the mineral electrodes were conditioned at a fixed potential for 10 min. The effects of pH, concentration of PAX and depressants such as sodium cyanide, sodium sulfide and MAA (a mixture of magnesium chloride, ammonium chloride and ammonium hydroxide) on the contact angle of synthetic and natural chalcopyrites were also investigated. The hydrophobic film on the chalcopyrite surface was extracted using hexane and examined by UV spectroscopy. Collector and collectorless microflotation of natural chalcopyrite under controlled potential at pH 10 was performed in order to determine the floatable potential range of chalcopyrite. The contact angle results indicated that synthetic and natural chalcopyrites have similar wettability. Their floatable potential range in 7×10⁻⁴ M PAX solution was −0.2 to 0.2 V vs. standard calomel electrode at pH 10 and was −0.25 to 0.3 V at pH 7. Sodium sulfide showed the strongest inhibiting effect among the three depressants investigated. The flotation results indicated that natural chalcopyrite floated in the pulp potential range of −0.087 to +0.2 V (vs. SCE and monitored by a platinum electrode) without collector and in the potential range of −0.2 to +0.205 V in the 7×10⁻⁴ M PAX solution.     

柠檬酸对蓝晶石浮选行为的影响研究

通过纯矿物浮选试验,研究了柠檬酸对蓝晶石浮选的调整作用。结果表明,在油酸钠浮选体系中,柠檬酸在不同的pH值条件下能不同程度的抑制蓝晶石的上浮,在十二胺浮选体系中,柠檬酸在不同的pH值条件下能不同程度的活化蓝晶石的上浮。利用量子化学计算前线轨道能量和分子动力学模拟研究水和柠檬酸在蓝晶石表面的吸附差异,模拟结果表明柠檬酸与蓝晶石的作用强于水与蓝晶石的作用,通过浮选溶液化学计算,分析了柠檬酸对蓝晶石的调整机理,柠檬酸组分可以与蓝晶石表面的铝离子络合,其中C_6H_7O_7~-和C_6H_6O_7~(2-)的作用效果比C_6H_6O_7~(3-)明显,同时增强了蓝晶石表面的负电性,抑制油酸钠在蓝晶石表面的吸附,而有利于十二胺在蓝晶石表面的吸附。     

从选钼尾矿中回收制钾肥长石选矿试验研究

黑龙江某大型钼矿选钼尾矿K2O品位为6.91%,Na2O品位为1.79%,经过试验研究采用脱泥-浮选除杂-长石浮选-强磁选除杂的工艺流程,选钼尾矿脱泥后采用油酸钠浮选除杂,然后添加硫酸调整pH值至3.6,采用BK440作长石捕收剂浮选分离长石与石英,长石浮选精矿在15000kA/m场强下脱除磁性矿物,获得长石精矿K2O品位为11.54%, Na2O品位为2.51%,K2O回收率为47.73%;Na2O回收率为40.30%。长石精矿达到制钾肥钾长石质量标准。     

硫酸铵对蓝铜矿硫化浮选的影响及基因机理分析

氧化铜矿物作为铜矿资源的重要组成部分,提高其开发利用技术对于铜矿资源的高效综合回收具有重要意义,蓝铜矿是重要的氧化铜矿物,但自然可浮性较差,通常采用硫化浮选。通过单矿物浮选试验,考察硫酸铵对蓝铜矿硫化浮选的影响。通过矿物表面丁基黄药吸附量分析药剂作用前后矿物表面元素种类和含量的变化,以及药剂在矿物表面吸附能的模拟计算,研究硫酸铵对蓝铜矿硫化浮选的活化机理。结果表明,硫酸铵用量为 200 mg/L 时使蓝铜矿硫化浮选回收率由 44.15%（未添加时）增加至 60.03%,矿物表面 X 射线光电子能谱分析表明,硫酸铵使蓝铜矿矿物表面铜和硫含量增加,碳和氧含量减少,改善矿物表面硫化效果,增加矿物表面疏水性和丁基黄药吸附量。通过 Material studio 模拟计算结果表明,硫酸铵降低了丁基黄药以及硫化剂在蓝铜矿表面的吸附能,增加了丁基黄药和硫化钠在矿物表面的吸附稳定性,对蓝铜矿的硫化浮选具有活化作用。     

新疆某难选硫化铜镍矿选矿试验研究

根据新疆某硫化铜镍矿矿石的工艺矿物学特性,进行了详细的选矿试验研究,采用一粗一精两扫、中矿顺序返回的铜镍混合浮选流程,使用碳酸钠做pH调整剂,六偏磷酸钠做分散剂,羧甲基纤维素做抑制剂,混合黄药做捕收剂,处理该矿石,得到了混合精矿含镍10.89%、含铜4.27%,镍回收率81.61%、铜回收率85.03%的指标,氧化镁含量低于6.8%,产品质量符合冶炼要求。对六偏磷酸钠和羧甲基纤维素在硫化铜镍矿浮选中的作用机理进行了分析,结果表明六偏磷酸钠能分散蛇纹石与硫化矿物,降低蛇纹石对硫化矿物浮选的影响,而羧甲基纤维素能抑制含镁硅酸盐矿物的上浮,实现硫化矿物与含镁硅酸盐脉石的浮选分离。因此,在含有多种镁硅酸盐脉石矿物的硫化铜镍矿中同时使用六偏磷酸钠和羧甲基纤维素是该类矿石高效利用的关键。     

Mg2+对油酸钠捕收石英的活化机理研究

石英矿物中常伴生有Mg²⁺,为了解Mg²⁺对油酸钠浮选石英的影响,进行了石英纯矿物浮选试验,并采用Zeta电位测试、溶液化学计算和红外光谱分析方法对Mg²⁺活化石英的机理进行了研究。结果表明：①在没有Mg²⁺存在的情况下,油酸钠对石英没有捕收能力;当矿浆pH=10.5,Mg²⁺浓度为3.75×10^-4 mol/L,油酸钠浓度为6.25×10^-4 mol/L时,石英的浮选回收率可达92.40％。②Zeta电位分析表明,吸附在石英表面的Mg2+是油酸钠吸附的活性位点,因而Mg²⁺对油酸钠浮选石英有活化作用。③溶液化学分析表明,Mg²⁺活化石英的有效成分为MgOH⁺。④红外光谱分析表明,有Mg²⁺存在的情况下,油酸钠才能吸附到石英颗粒表面。     

Bubble attachment time and FTIR analysis of water structure in the flotation of sylvite, bischofite and carnallite

Water structure is the most important parameter that influences the flotation of soluble salts. In this paper bubble attachment time measurements and FTIR analyses were performed to investigate the effect of water structure on the flotation behavior of sylvite (KCl), bischofite (MgCl₂·6H₂O) and carnallite (KMgCl₃·6H₂O). The results from bubble attachment time measurements suggest that collector adsorption at the surface of KCl induces flotation with either the cationic collector, ODA, or anionic collector, SDS. In contrast bubble attachment did not occur for bischofite (MgCl₂·6H₂O) or carnallite (KMgCl₃·6H₂O). Results show that the surface charge is not a determining factor in the flotation of soluble salts.Further, the interaction between water molecules and the three chloride salts dissolved in aqueous solution were studied by measuring the shift in the hydrogen-bonding of water molecules. The results indicate that KCl is a structure breaker salt, while MgCl₂·6H₂O and KMgCl₃·6H₂O are structure maker salts.Viscosities for the brines of these three salts were determined. The results give additional evidence of differences in water structure and are in good agreement with the FTIR and bubble attachment results. The findings provide further evidence that water structure plays an important role in the flotation of soluble salts.