兰坪高硅氧化锌矿矿物组成及高温酸浸热力学分析

云南兰坪地区的高硅氧化锌矿储量极为丰富,用化学物相分析、X射线衍射、扫描电镜能谱等表征手段对该矿的工艺矿物学研究,结果表明:矿石中锌主要以异极矿和菱锌矿的形式存在,脉石矿物以石英砂为主,并伴有少量的方解石,云母等,有价矿物和脉石之间相互镶嵌或包裹,从而造成矿石结构复杂。采用高温酸浸工艺可有效避免硅胶的危害,热力学分析表明:在高温酸性体系中高硅氧化锌矿中锌矿物的溶解较为彻底,较低的酸度和较高的温度可减少矿物中铁的溶解且能有效地将酸溶硅转化为沉淀形式。     

云南某含易浮硅矿物锌矿选矿的试验研究与生产实践

云南某含大量易浮硅矿物锌矿含锌4.84%,含硅达28.85%,是非常典型难处理的含硅锌矿。针对该矿石特点,进行了大量捕收剂的选择和易浮硅矿物抑制剂复配的试验研究,成功寻找到了适合该锌矿的捕收剂,并开发了抑制易浮硅矿物的SCA抑制剂,试验研究应用于生产,获得锌精矿含锌品位达52.17%,锌回收率91.40%,达到了较好的选矿指标。     

某新型抑制剂在铜锌分离中的试验研究

针对某复杂难选铜锌矿石,采用优先选铜原则流程进行铜锌分离,利用小分子有机抑制剂抑制锌矿物,分离效果良好。小型闭路试验可获得铜精矿含铜23.15%、铜回收率为77.61%、含锌5.61%,与常规锌组合抑制剂Zn SO4+Na2SO3相比,新药剂可使铜精矿中铜品位和回收率分别提高3.91和7.36个百分点、杂质锌的含量降低2.61个百分点,锌精矿的锌品位与回收率分别提高了0.66%、0.31%。     

An innovative process for extracting boron and simultaneous recovering metallic iron from ludwigite ore

Ludwigite ore has not yet been utilized on an industrial scale due to its complex mineralogy and fine mineral dissemination in China. Boron–iron separation and dissolution activity of boron-bearing minerals in alkaline liquor are the two key issues in the utilization of ludwigite ore, governing the boron recovery as well as operating cost. This paper proposes an innovative process for extraction of boron and iron from ludwigite ore based on coal-based direct reduction process with sodium carbonate (Na₂CO₃). The novel process involves reduction roasting, combined leaching and grinding of reduced ludwigite ore, followed by magnetic separation of leach residue, and experimental validation for each of the processing steps is demonstrated. Alkali-activation of boron and metallization of iron were synchronously achieved during carbothermic reduction of ludwigite ore in the presence of Na₂CO₃. Consequently, boron was readily extracted in the form of sodium metaborate (NaBO₂) with water at room temperature during ball mill grinding, and metallic iron powder was recovered from the leaching-filtering residue by magnetic separation. Boron extraction of 72.1% and iron recovery of 95.7% with corresponding iron grade of 95.7% in the magnetic concentrate were achieved when ludwigite ore was reduced with 20% sodium carbonate at 1050 °C for 60 min.     

Leaching of manganese ores using sawdust as a reductant

In this study sawdust was used as reductant for sulphuric acid leaching of manganese ore. Effects of pulp density, amount of acid, temperature, particle size of ore and amount of sawdust were studied. Manganese extraction of ∼98% was achieved under the conditions: leaching time 8 h, 5% H₂SO₄ (v/v), 10% pulp density, 90 °C and 5% sawdust (w/w), i.e. 0.5 g/g ore. Other Mn containing materials like low grade manganese ore, manganese nodule and Mn-nodule leach residues were tested and all these materials responded well giving more than 98% Mn extraction.     

某微细粒含碳高硫铅锌矿选矿试验研究

某铅锌矿含铅7.41%、锌13.70%、硫31.25%、碳1.45%,铅锌矿物嵌布粒度微细,属微细粒高硫含碳难选硫化铅锌矿。根据矿石性质,采用“脱碳—铅锌依次优先浮选—铅锌粗精矿再磨精选”工艺流程考察了碳粗选磨矿细度、铅锌粗精矿再磨细度和铅锌浮选药剂制度对选别指标的影响。结果表明,以BK9032为方铅矿捕收剂,以硫酸锌+亚硫酸钠为铅粗精矿精选组合抑制剂,以石灰为黄铁矿抑制剂和pH调整剂,丁基黄药为闪锌矿捕收剂,在碳粗选磨矿细度为-0.074 mm占98%条件下,经实验室闭路试验,可获得铅品位57.91%、铅回收率85.24%的铅精矿和锌品位53.44%、锌回收率86.17%的锌精矿。     

丹寨县某铅锌矿选矿试验

为给丹寨县某硫化铅锌矿石的开发利用提供技术依据,在对矿石进行工艺矿物学研究基础上,采用优先浮铅再浮锌流程进行了铅锌选矿试验。结果表明,在磨矿细度为-0.074 mm占80%,铅粗选CaO用量为2 500 g/t、ZnSO₄+Na2SO₃为1 500+1 000 g/t、乙硫氮+丁铵黑药为10+10 g/t、2^#油为18 g/t,锌粗选CuSO₄用量为600 g/t、丁基黄药用量为130 g/t情况下,采用1粗1精1扫浮铅、1粗1精2扫浮锌、中矿顺序返回流程处理该矿石,获得了铅品位为48.72%、含锌4.95%、铅回收率为89.21%的铅精矿,以及锌品位为45.89%、含铅0.72%、锌回收率为82.42%的锌精矿。     

会理铜铅锌多金属硫化矿浮选新工艺研究

会理锌矿随着开采的延深,矿石中铜含量加大,形成了铜铅锌多金属复杂硫化矿。而原浮选流程只有选铅和选锌作业,已不能适应矿石性质的变化。为此,以LP-01为铜矿物的捕收剂、乙硫氮为铅矿物的捕收剂、硫酸铜和丁黄药为锌矿物的活化剂和捕收剂、石灰为矿浆电位调整剂,并在选铜、铅时配合使用铅矿物的组合抑制剂ZnSO₄+YN,对该多金属复杂硫化矿进行了电位调控铜、铅、锌依次优先浮选新工艺试验研究,获得了含铜21.74%、铜回收率62.31%的铜精矿,含铅61.23%、铅回收率55.07%的铅精矿和含锌56.43%、锌回收率90.02%的锌精矿。新工艺流程简单,对环境友好,可作为现场工艺改造的依据。     

鄂西某高磷鲕状赤铁矿磁化焙烧及浸出除磷试验

针对鄂西某高磷鲕状赤铁矿(铁品位43.50%),在实验室条件下采用磁化焙烧—磁选工艺获取铁精矿,并对该铁精矿进行酸浸、生物浸出除磷试验。研究结果表明,在焙烧温度850℃,焙烧时间25min,还原剂用量为矿石质量的5%,磨矿时间4min,磁场强度120kA/m条件下,得到铁精矿铁品位为54.92%,铁回收率为86.78%,P含量为0.83%;酸浸试验中矿浆浓度2%,分别用0.1mol/L的H2SO4,HNO3,HCl,草酸(C2H2O4),柠檬酸(C6H8O7)除磷,其中H2SO4除磷提铁效果最佳,铁精矿品位为57.98%,回收率为96.47%,除磷率为95.30%;生物浸出试验中矿浆浓度2%,用嗜酸氧化亚铁硫杆菌(At.f菌)对铁精矿作用后,磷含量为0.23%,用黑曲霉菌滤液对铁精矿作用后,磷含量为0.20%。     

微波-化学溶液联合作用下矿石的劣化机理研究

为了提高微波辅助磨矿的适用性,以红透山铜矿和思山岭铁矿为研究对象,分别采用微波、盐酸溶液、草酸溶液及其组合的方式对矿石进行预处理.对比了7种预处理方式下矿石的升温特征、表面形态、磨矿效果,并通过介电常数、波速、微观照片揭示矿石的劣化机理.试验结果表明:铜矿和铁矿浸酸后介电常数减小,导致微波作用下升温速率降低,温度分布更...     

Mineral carbonation of PGM mine tailings for CO2 storage in South Africa: A case study

The ultra-fine milled tailings generated during the processing of PGM ores in South Africa have a theoretical potential to sequester significant amounts of CO₂ (∼14 Mt per annum) through mineral carbonation. Mg-bearing orthopyroxene is the major sequestrable mineral in these tailings, which also contains significant quantities of Ca-bearing plagioclase, as well as minor quantities of clinopyroxene, olivine, serpentine and hornblende. In this study, the feasibility of using PGM tailings to sequester CO₂ has been investigated empirically using the two-step, pH swing method. The rates and extents of cation (Ca, Mg and Fe) extraction and subsequent carbonation were determined and compared. Both organic (oxalic and EDTA) and HCl solutions were utilised in the cation extraction step, which was conducted at time periods up to 8 h and at a temperature of 70 °C. The extents of cation dissolution were relatively low under all experimental conditions investigated, particularly for the case of Mg (between 3.3% and 5.0% extraction). A comparison of the extents of leaching with the mineralogical composition of the tailings indicated that the extracted Mg originated primarily from clinopyroxene, with the orthopyroxene remaining relatively inert under the experimental conditions. Subsequent carbonation of the acid leach solution after pH adjustment with NaOH resulted in the rapid formation of a number of carbonate minerals, including gaylussite (Na₂Ca(CO₃)₂·5(H₂O)), magnesite (MgCO₃), hydromagnesite (Mg₅(CO₃)₄(OH)₂·4H₂O), dolomite (CaMg(CO₃)₂), ankerite (Ca(Fe,Mg)(CO₃)₂), and siderite (FeCO₃). On the basis of these findings, further studies will be focused on developing a better understanding of the factors affecting the dissolution of Mg-bearing orthopyroxene minerals, and on exploring alternative leach reagents and conditions, with a view to developing a more effective process for the accelerated carbonation of PGM tailings.     

氧气传质对湿法炼锌过程中针铁矿法除铁的影响研究

湿法炼锌采用还原-氧化法(V.M.针铁矿法),对硫化锌精矿氧压浸出液中的铁离子进行去除,探究不同通气方式和氧气流量对除铁过程的影响。研究发现氧气的传质对氧化除铁过程有显著的影响,强化搅拌对氧气的传质影响较小,但曝气可以大大提高氧气的分散度,增加氧气传质,加快Fe_²⁺氧化速率,从而提高铁的去除效率率。研究结果表明,氧气流量≥1l/min时,氧气流量对铁的去除影响较小;在不添加晶种时,曝气氧化除铁形成大量非晶态的物质,该物质可能是铁水化合物(5Fe₂O₃.9H₂O),因吸附其他离子,阻碍沉淀物向针铁矿转变。研究结果将对湿法炼锌过程中的还原-氧化法(V.M.针铁矿法)除铁具有一定的参考价值。     

都龙难选锌矿物选矿工艺试验研究

试样锌矿物难选的主要因素为易浮硅质矿物和硫铁矿的于扰。AC抑制剂能有效地抑制易浮硅质矿物;ZJ 捕收剂的选择性较好,对易浮硅质矿物的捕收弱,同时ZJ捕收剂与硫化矿物的吸附作用不是很牢,精选时捕收剂较易脱落,有利于抑制硫铁矿;将锌精选Ⅰ的尾矿经扫选后直接排尾,较好地解决了硫铁矿在浮锌系统的恶性循环问题,有利于提高锌精矿的锌品位。采用较简单的工艺流程对都龙难选锌矿物进行浮锌试验,取得较好的技术指标。     

A preliminary research on acid pressure leaching of pyritic copper ore in Kure Copper Mine, Turkey

The combination of roasting and pressure leaching is an alternative process that offers advantages over conventional processes because of the shorter leaching time and higher metal recovery. The copper and iron sulphide minerals examined in this study were chalcopyrite (CuFeS₂) and pyrite (FeS₂). The best results obtained were with a pre-treatment by roasting followed by acid pressure leaching in an autoclave system. The extraction of copper achieved was over 85%. Copper dissolution in this system is affected by particle size, leaching time and oxygen pressure. This paper presents the preliminary research on acid leaching of pyritic copper ore in an autoclave system under laboratory conditions.     

Surface properties of enargite in MAA depressant solutions

Enargite (Cu₃AsS₄) is a common penalty mineral in the copper mining industry. Different treatment methods have been proposed to passivate the enargite surface for effective flotation of non-arsenic copper minerals, including pulp potential control, pre-oxidation and chemical depression. Magnesium ammonium mixture (MAA) has been previously tested, showing good selectivity for arsenic rejection. It was hypothesised that MAA would make the enargite surface hydrophilic by adsorption of magnesium ammonium arsenate hexahydrate (MgNH₄AsO₄·6H₂O). Here we show that MAA does not selectively adsorb onto the enargite surface as conjectured. X-ray photoelectron spectroscopy and cyclic voltammetry show that magnesium compounds do not precipitate onto the enargite surface at pH 10, whereas magnesium hydroxide on the enargite surface is formed at pH 12. MgNH₄AsO₄·6H₂O was not observed at either pH 10 or pH 12. The effect of pre-oxidation to promote dissolution of (AsO₄)³⁻ before conditioning with MAA, which could help catalyse the formation of MgNH₄AsO₄·6H₂O, was also tested. However, the results were the same as those without pre-oxidising the sample. Our investigation shows that under alkaline conditions it is not possible to passivate the enargite surface in MAA solutions for effective flotation of non-arsenic copper minerals.     

微波加热低品位氧化镍矿石的FeCl3氯化

将微波加热用于低品们氧镍矿石的氯化焙烧，产出的焙砂用稀酸浸出。结果表明，采用微波加热代替传统加热时，可以提高镍的浸出率。减小矿石始粒度、增加微波辐射功率可以提高镍的浸出率，适当增加反应时间和氯化剂ＦｅＣｌ３的加入量，有助于提高镍的浸出率，但当微波辐身时间超过２０ｍｉｎ、ＦｅＣｌ３的加入量超过２８％时，镍的浸出率反而下降。在最佳条件下，镍的浸出率可以达到７１．６５％。     

采用微波助磨技术处理惠民铁矿的研究

采用微波高温箱式加热装置研究微波对惠民铁矿磨细的辅助作用。考察了该矿在微波场下的升温行为及微波加热对矿物孔隙率、内部裂隙及矿物磨细的影响。结果表明,惠民氧化铁矿在微波作用下能够在100s内被加热至600℃以上,并且微波处理后矿物孔隙率提高24.04%,相同磨矿条件下-200目产品的产率提高7.3%～11.3%,SEM微观结构物相分析显示微波处理后矿物产生大量的晶界间裂隙。     

Recovery of zinc and cadmium from industrial waste by leaching/cementation

Metallic zinc production from sulfide zinc ore is comprised by the stages of ore concentration, roasting, leaching, liquor purification, electrolysis and melting. During the leaching stage with sulfuric acid, other metals present in the ore in addition to zinc are also leached. The sulfuric liquor obtained in the leaching step is purified through impurities cementation. This step produces a residue with a high content of zinc, cadmium and copper, in addition to lead, cobalt and nickel. This paper describes the study of selective dissolution of zinc and cadmium present in the residue, followed by the segregation of those metals by cementation. The actual sulfuric solution, depleted from the electrolysis stage of metallic zinc production, was used as leaching agent. Once the leaching process variables were optimized, a liquor containing 141 g/L Zn, 53 g/L Cd, 0.002 g/L Cu, 0.01 g/L Co and 0.003 g/L Ni was obtained from a residue containing 30 wt.% Zn, 26 wt.% Cd, 7 wt.% Cu, 0.35 wt.% Co and 0.32 wt.% Ni. The residue mass reduction exceeded 80 wt.%. Cementation studies investigated the influence of temperature, reaction time, zinc concentration in feeding solution, pH of feeding solution and metallic zinc excess. After that such variables were optimized, more than 99.9% of cadmium present in liquor was recovered in the form of metallic cadmium with 97 wt.% purity. A filtrate (ZnSO₄ solution) containing 150 g/L Zn and 0.005 g/L Cd capable of feeding the electrolysis zinc stage was also obtained.     

The effect of sodium sulphate on the hydrogen reduction process of nickel laterite ore

A series of nickel laterite ores with different calculated amounts of anhydrous sodium sulphate were prepared by physical blending or sodium sulphate solution impregnation. The reduction of the prepared nickel laterite ore by H₂ was carried out in a fluidised-bed reactor with provisions for temperature and agitation control, and the magnetic separation of the reduced ore was performed using a Davis tube magnetic separator. The mineralogical properties of the raw laterite ore, reduced ore and magnetic concentrate were characterised using ICP, TG–DSC, N₂ adsorption, X-ray diffraction and optical microscopy. The catalytic activity of sodium sulphate was also studied by using Hydrogen temperature-programed reduction. The experimental results indicate that Na₂SO₄ could overcome the kinetic problems faced by the laterite ore and that it exhibited noticeable catalytic activity only if the temperature reached at least 750 °C. This high temperature accelerated the crystal phase transition of the silicate minerals and increased the utilisation of H₂. In comparing the results from the two different methods for adding Na₂SO₄, the nickel content and recovery of the magnetic concentrate were increased by using the impregnation method rather than the physical blending method and the increasing amount of sodium sulphate assisted in the further beneficiation of nickel. The partial pressure of H₂ and the reducing time also affected the reduction process of the iron oxides. The results of the microscopic study indicated that the formation of a Fe–S solid solution, which was derived from the SO₂ sulphide reduction of FeO, was conducive to mass transfer and accelerated the coalescence of metallic ferronickel particles. For the nickel laterite ore, under the synergistic effect of sodium sulphate and hydrogen, a nickel content and nickel recovery of 6.38% and 91.07% were obtained, respectively, with high product selectivity.     

Acid leaching of metals from deep-sea manganese nodules – A critical review of fundamentals and applications

The mass% metal composition of deep sea nodules ranges from 10–28% Mn, 4–16% Fe, 0.3–1.6% Ni, 0.02–0.4% Co, and 0.1–1.8% Cu in mixed oxide matrices with alumina and silica. The concentrations of base metal ions in sea water of pH ∼ 8 of the order 10⁻³–10² nmol/kg are shown to be dependent on the solubility products (K_SP) of carbonate sediments. Cations of higher softness have higher pK_SP and lower solubility. Previously reported leach results of nodules in H₂SO₄ and HCl under atmospheric pressure and temperatures in the range 30–90 °C and in the absence or presence of SO₂, Na₂SO₃, NaCl and CaCl₂ are used in the present study to compare, contrast and rationalise the leaching behaviour of metal values. Leach efficiency of metals increases with increasing acid concentration, and Cu(II) and Zn(II) follow the same trend in HCl. Potential–pH diagrams of base metal oxides show a higher stability of mixed metal oxides such as ferrites, magnetite and manganite, which causes partial dissolution of high-valent oxides in the absence of reducing agents. Application of a shrinking core kinetic model in both H₂SO₄ and HCl media predicts a proton diffusivity of ∼ 10⁻¹¹ cm² s⁻¹ for the dissolution of Ni from nodules. This value is of the same order as D_H⁺ for the high pressure acid leaching of Ni from limonitic laterite. A linear correlation between leaching efficiencies of Fe and Ni appears to be a result of co-dissolution of these metals from NiO·Fe₂O₃ or NiFeOOH. The first order dependence of initial dissolution rates of Cu(II) with respect to H⁺ concentration in H₂SO₄, and the beneficial effect of background chloride ions, suggests a dissolution mechanism: CuO → Cu(OH)Cl_ads/aq → CuSO₄. The Cu(II) ions in solution can also affect Ni(II) dissolution from oxide by cation exchange mechanism. The presence of SO₂ or Na₂SO₃ as reducing agents facilitates the acid leaching of high-valent oxides of Mn and Co and other metals incorporated in the mixed oxide matrix. Whilst Fe(II) ions formed during the reductive leaching of Fe(III)-oxides accelerate the dissolution of Mn(III)/(IV) oxides, the resultant Mn(II) ions accelerate the dissolution of high-valent Co-oxides. Leaching efficiency in HCl increases with temperature. As for the SO₂/H₂O system thermodynamic calculations predict a decrease in concentration of H⁺ and at high temperatures, which retards leaching efficiency. The SO₂/H₂O/air leach system enhances metal dissolution due to the production of H₂SO₄ via the transition metal catalysed oxidation of SO₂ to H₂SO₄.