Action time effect of lime on its depressive ability for pyrite

Two sample groups of bulk concentrates consisting mainly of pyrite and chalcopyrite from Daye and Chenghchao Mines in Hubei Province of China were used to investigate the effect of the action time of lime on its depressive ability for pyrite. The experimental results conducted with different samples and collectors showed that the action time between lime and pyrite markedly influences the depressive ability of lime. The depressive ability of lime increased with the action time increasing. It was also proved that the depressive results obtained at a large lime dosage after a shorter action time are similar to those obtained at a small lime dosage after a longer action time. The increase of depressive ability of lime after a longer action time is because that there are different mechanisms in different action time. The composition on the surface of pyrite acted for different time with lime was studied by using ESCA (Electron Spectroscopic Chemical Analysis). The results showed that iron hydroxide and calcium sulphate formed on the pyrite surface at the presence of lime in the pulp but the amounts of iron hydroxide and calcium sulphate were different at different action time. At the beginning action time the compound formed on the pyrite surface was mainly calcium sulphate and almost no iron hydroxide formed; but with the action time increasing, iron hydroxide formed. The longer the action time, the more iron hydroxide and the less calcium sulphate formed. It was considered that the stronger depressive ability of lime after a longer action time is because more iron hydroxide forms on the pyrite surface.     

Effect of organic depressant lignosulfonate calcium on separation of chalcopyrite from pyrite

In order to selectively separate chalcopyrite from pyrite, the effect of organic depressant lignosulfonate calcium (LSC) on the flotation separation of chalcopyrite from pyrite was investigated by flotation tests. The depression mechanism was studied by Fourier-transform-infrared (FTIR) analysis. The flotation tests of single mineral show that LSC can depress the flotation of pyrite in a certain pH range, but it has little effect on chalcopyrite flotation. Flotation separation of a mixture of chalcopyrite and pyrite can be completed to obtain a copper concentrate grade up to 24.73% with a recovery of 80.36%. IR analysis shows that LSC and butyl xanthate compete in absorption on pyrite surface, and there exists an LSC characteristic peak on pyrite surface. There is little adsorption of LSC on chalcopyrite.     

絮凝剂WHL1在过滤中的助滤行为

实验通过改变絮凝剂WHL1的使用条件(如分子量、用量、矿浆pH值和过滤压差等)来研究其在铜精矿过滤中的助滤行为.结果表明:当矿浆pH约为10,用量为20 g/t,分子量为3×106,水解度为40%时,WHL1既能提高过滤速度,又对降低滤饼水分有所作用.     

Zinc bioleaching from an iron concentrate using Acidithiobacillusferrooxidans strain from Hercules Mine of Coahuila, Mexico

The iron concentrate from Hercules Mine of Coahuila,Mexico,which mainly contained pyrite and pyrrhotite,was treated by the bioleaching process using native strain Acidithiobacillus ferrooxidans(A.ferrooxidans)to determime the ability of these bacteria on the leaching of zinc.The native bacteria were isolated from the iron concentrate of the mine.The bioleaching experiments were carried out in shake flasks to analyze the effects of pH values,pulp density,and the ferrous sulfate concentration on the bioleaching process.The results obtained by microbial kinetic analyses for the evaluation of some aspects of zinc leaching show that the native bacteria A.ferrooxidans,which is enriched with a 9K Silverman medium under the optimum conditions ofpH 2.0,20 g/L pulp density,and 40 g/L FeSO4,increases the zinc extraction considerably observed by monitoring duringl 5 d,i.e.,the zinc concentration has a decrease of about 95％ in the iron concentrate.     

Bioleaching of chalcopyrite by. mixed culture of moderately thermophilic microorganisms

A mixed culture of moderately thermophilic microorganisms was enriched from acid mine drainages(AMDs)samples collected from several sulphide mines in China,and the bioleaching of chalcopyrite was conducted both in shake flask and bioreactor.The results show that in the shake flask,the mixture can tolerate 50 g/L chalcopyrite after being acclimated to gradually increased concentrations of chalcopyrite.The copper extraction increases obviously in bioleaching of chalcopyrite with moderately thermophilic microorganisms supplemented with 0.4 g/L yeast extract at 180 r/min,74% copper can be extracted in the pulp of 50 g/L chalcopyrite after 20 d.Compared with copper extractions of mesophilic culture,unacclimated culture and acclimated culture without addition of yeast extract,that of accliniated culture with addition of yeast extract is increased by 53%,44% and 16%,respectively.In a completely stirred tank reactor,the mass fraction of copper and total iron extraction reach up to 81% and 56%,respectively.The results also indicate that it is necessary to add a large amount of acid to the pulp to extract copper from chalcopyrite effectively.     

脂类捕收剂DLZ对黄铜矿和黄铁矿浮选的选择性作用

通过浮选实验、吸附量和红外光谱测定,考察了捕收剂DLZ对黄铜矿和黄铁矿浮选性能的影响及作用机理.结果表明:DLZ在pH=2.7～12.05时对黄铜矿的捕收能力强,最大回收率95.7%,而对黄铁矿的捕收能力弱,且PH=6.9～12.05时其回收率小于10%.用CaO作pH调整剂时,在pH=7～11时黄铜矿的回收率与用NaOH调PH相差不大,但黄铁矿可浮性被抑制,回收率低于5%.DLZ在黄铜矿上的吸附量比在黄铁矿上的大,特别是强碱条件下;其吸附量随用量的增加而增大.DLZ与矿物作用的红外光谱分析表明:黄铜矿与DLZ作用后出现了DLZ的相关特征吸收峰,而黄铁矿与DLZ以及Cu~(2+)作用前后的红外光谱曲线基本没有变化,可见DLZ在黄铜矿表面的吸附属于化学吸附,在黄铁矿表面的吸附属于物理吸附.     

Influences of collector DLZ on chalcopyrite and pyrite flotation

The interaction mechanism of collector DLZ in the flotation process of chalcopyrite and pyrite was investigated through flotation experiments, zeta potential measurements and infrared spectrum analysis. Flotation test results indicate that DLZ is the selective collector of chalcopyrite. Especially, the recovery of chalcopyrite is higher than 90% in neutral and weak alkaline systems, while the recovery of pyrite is less than 10%. When using CaO as pH regulator, at pH=7-11, the floatability of pyrite is depressed and the recovery is less than 5%. Zeta potential analysis shows that the zeta potential of chalcopyrite decreases more obviously than that of pyrite after interaction with DLZ, confirming that collector DLZ shows selectivity to chalcopyrite and pyrite. And FT1R results reveal that the flotation selectivity of collector DLZ is due to chemical absorption onto chalcopyrite surface and only physical absorption onto pyrite surface.     

Flotation behaviors of chalcopyrite and galena using ferrate(Ⅵ) as a depressant

This paper investigated the effects of potassium ferrate(PF) on the flotation performances of chalcopyrite and galena. The flotation results showed that PF obviously depressed galena, but had little effects on the floatability of chalcopyrite within p H range of 4.0–12.0. Zeta potential tests showed that the addition of PF induced the formation of more amounts of hydrophilic species on the surface of galena under an alkaline environment. Industrial grade O-isopropyl-N-ethyl thionocarbamate(IPETC...     

Removal of phosphorus from iron ores by chemical leaching

1 INTRODUCTION With the rise of the price of iron ores in the global market, the iron and steel companies in China have to increase the proportion of domestic iron ores in iron-making production. However, iron ores produced in China commonly contain many impurities, such as phosphorus, sulphur, silica, etc[1]. Phosphorus is one of the main harmful elements to ferrous metallurgy, and it will affect the quality of iron and steel products[2]. At present, China has explored some large mines,…     

Solvent extraction of copper and zinc from bioleaching solutions with LIX984 and D2EHPA

The solvent extraction of copper and zinc from the bioleaching solutions of low-grade sulfide ores with LIX984 and D2EHPA was investigated. The influences of extractant content, aqueous pH value, phase ratio and equilibration time on metals extraction were studied. The results show that LIX984 has a higher selectivity for copper than for iron, zinc and other metals, and has the copper extraction rate above 97%, while the zinc and iron extraction rate is less than 1.6% respectively. Zinc extraction is carried out following the copper extraction from the raffinate. The zinc extraction with di(2-ethylhexyl) phosphoric acid(D2EHPA) is low due to its poor cation exchange. A sodium salt of D2EHPA is used and the zinc extraction rate is enhanced to above 98%. Though iron (Ⅲ) is strongly extracted before the extraction of zinc by D2EHPA, it is difficult to strip iron from the organic phase by sulfuric acid. The zinc stripping rate is above 99% with 100 g/L sulfuric acid, while that of iron is 0.16%. Hence,the separation of zinc from iron can be achieved by the selective stripping.     

Effect of pyrite content of feed and configuration of locked particles on rougher flotation of copper in low and high pyritic ore types

Misreported pyrite into copper concentrates dramatically declines copper grade and recovery. Copper flotation can be also more complicated if flotation feed comes from an elevated-pyritic copper ore. In this investigation, the effect of two different ore types(high pyritic and low pyritic feeds) was studied on rougher stage of industrial copper flotation circuit. Samples were taken from different streams and the structure of chalcopyrite within the pyrite and non-sulfide gangue minerals was examined in various size fractions for mentioned ore types. Results indicated that 72% and 56% of the total floated pyrite was transferred to concentrate in first four cells in the low and high pyritic feeds, respectively. Whereas, this proportion for floated SiO_2 in last ten cells was detected as 72% and 71%, respectively. A detailed interpretation of the effect of locked particles in different size fractions on rougher flotation cells is studied from industrial point of view.     

Modeling and process optimization for microbial desulfurization of coal by using a two-level full factorial design

The microbial sulfur removal was investigated on high sulfur content (1.9%) coal concentrate from Tabas coal preparation plant. A mixed culture of ferrooxidans microorganisms was isolated from the tailing dam of the plant. Full factorial method was used to design laboratory test and to evaluate the effects of pH, particle size, iron sulfate concentration, pulp density, and bioleaching time on sulfur reduction. Statistical analyses of experimental data were considered and showed increases of pH and particle size had negative effects on sulfur reduction, whereas increases of pulp density and bioleaching time raised microbial desulfurization rate. According to results of designing, and regarding statistical factors, the optimum values for maximum sulfur reduction were obtained; pH (1.5), particle size (?180 μm), iron sulfate concentration (2.7 mmol/L), pulp density (10%) and bioleaching time (14 d), which leaded to 51.5% reduction from the total sulfur of sample.     

某铜铁矿选矿工艺研究

主要针对某铜铁矿矿石性质,研究其选矿工艺流程,最终确定选铜回路采用浮选工艺流程,浮选药剂为石灰和丁基黄药;选铁回路采用磁选工艺流程方案。最终铜精矿品位为20.53%、回收率94.50%,铁精矿品位58.54%、回收率72.30%,获得了较好的试验指标。     

Effect and mechanism of siderite on reverse anionic flotation of quartz from hematite

Reverse flotation technology is one of the most efficient ways to improve the quality and reduce impurity of iron concentrate. Mineral processors dealing with hematite face a challenge that the flotation results of reverse flotation of hematite are poor in presence of siderite using fatty acid as collector, starch as depressant of iron minerals and calcium ion as activator of quartz at strong alkaline pH. In this work, the effect of siderite on reverse anionic flotation of quartz from hematite was investigated. The effect mechanism of siderite on reverse flotation of hematite was studied by solution chemistry, ultraviolet spectrophotometry(UV) and Fourier transform infrared spectroscopy(FTIR). It was observed that siderite had strong depressive effect on quartz in flotation using sodium oleate as collector, corn starch as depressant of iron minerals and calcium chloride as activator of quartz at strong alkaline pH. The starch was adsorbed onto calcium carbonate by chemical reaction which was formed by CO~(2-)_3 from siderite dissolution and Ca~(2+) from calcium chloride as activator of quartz and precipitated on the surface of quartz, which resulted in improving the hydrophilic ability of quartz.     

复合白云石表面链状纳米CaCO_3的制备

在Ca(OH)_2-H_2O-CO_2反应体系中,根据非均匀成核原理,通过调整体系反应温度、Ca(OH)_2浓度、ZnSO_4添加量等反应参数,控制在白云石颗粒表面生成具有链状结构的纳米Ca-CO_包覆层.利用SEM,XRD等检测表征手段,分析了不同反应参数对纳米CaCO_3晶形的影响.结果表明:当反应温度为25℃,ZnSO_4加入量为Ca(OH)_2的4%,Ca(OH)_2浓度为0.3mol/L时,在白云石颗粒表面生成了长径比为7:1的链状纳米CaCO_3.提高体系的反应浓度能够减少ZnSO_4的加入量.     

紫外-可见分光光度法快速测定硫酸粘杆菌素E

采用紫外-可见分光光度法快速测定硫酸粘杆菌素E的含量.在硫酸铜-氢氧化钠溶液体系中,与硫酸粘杆菌素E作用,形成缔合物,溶液颜色发生改变,其最大显色波长为540 nm.移取10 mL样品储备液于25 mL容量瓶中分别加入2 mL硫酸铜溶液和2 mL氢氧化钠溶液,并稀释到刻度,30℃水浴下15 min时,摇匀过滤,纯水做空白540 nm处比色.标准加入回收率为(n=6)99.5%.该方法用于工业化生产中的中间过程的控制,快速简便、易于操作.     

硫酸铜酸性镀铜法制备铜-康铜热电堆的最佳实验条件研究

热电堆是一种常见的热流传感器,热电堆的电镀效果直接影响其性能。基于硫酸铜酸性镀铜基本原理,通过在康铜基体上电镀铜的方式制备热电堆。研究了电镀时间、硫酸铜浓度、硫酸浓度、溶液温度、电流密度对热电堆输出热电势的影响。结果表明,最佳电镀条件为：电镀时间20 min,硫酸铜浓度250 g/L,硫酸浓度60 g/L,镀液温度36℃,电流密度10 A/dm2。在此条件下制备的铜-康铜热电堆输出热电势最高。     

REDUCTION OF FERRIC IRON IN THE TITANIUM SULFATE SOLUTION BY THE ION EXCHANGE MEMBRANE PRIMARY CELL METHOD *

Ｉｎｔｈｅｐｒｏｃｅｓｓｏｆｐｒｏｄｕｃｉｎｇｔｉｔａｎｉｕｍｄｉｏｘｉｄｅｗｉｔｈｓｕｌｆｕｒｉｃａｃｉｄ,ｔｈｅｐＨｖａｌｕｅｓｏｆＦｅ３＋ｈｙｄｒｏｌｙｓｉｓａｎｄＴｉ４＋ｈｙｄｒｏｌｙｓｉｓａｒｅｖｅｒｙｃｌｏｓｅ．ＩｎｏｒｄｅｒｔｏｐｒｅｖｅｎｔＦｅ３＋ｉｎｔｈｅｌｅａｃｈｉｎｇｓｏｌｕｔｉｏｎｆｒｏｍｈｙｄｒｏｌｙｚｉｎｇｉｎｔｈｅｆｏｒｍｏｆｈｙｄｒｏｘｉｄｅｏｒｂａｓｉｃｓｕｌｆａｔｅｉｎｔｈｅｈｙｄｒｏｌｙｓｉｓｓｔａｇｅｏｆＴｉＯＳＯ４,ａｎｄｆｒｏｍｃｏｎｔａｍｉｎａｔｉｎ…     

难免离子对中低品位钙镁质磷矿石反浮选的影响

采用浮选试验,结合溶液化学计算、方差分析、扫描电镜和X射线荧光光谱分析等手段研究难免离子对中低品位钙镁质磷矿石反浮选的影响. 研究结果表明:矿浆中Ca²⁺和Mg²⁺会降低浮选磷精矿中P₂O₅含量而提高MgO含量,原因是Ca²⁺和Mg²⁺会沉淀捕收剂解离的RCOO^-,降低其有效浓度;SO₄^2-会降低磷精矿中P2O5回收率,其作用机理是由于SO₄²-能与Ca²⁺作用生成硫酸钙沉淀并覆盖在氟磷灰石和白云石表面,增强氟磷灰石的可浮性,导致氟磷灰石随白云石一起浮出;PO₄^3-对浮选影响较小;Ca²⁺、Mg²⁺、SO₄^2-和PO₄^3-对磷精矿中SiO₂、Al₂O₃和Fe₂O₃含量影响较小. 由于Ca²⁺和SO₄^2-分别对磷精矿P₂O₅品位和P₂O₅回收率影响显著,因此在回水利用过程中需控制矿浆中Ca²⁺和SO₄^2-浓度,降低其对浮选的影响.     

Mechanism of bioleaching chalcopyrite by Acidithiobacillus ferrooxidans in agar-simulated extracellular polymeric substances media

The mechanism of leaching chalcopyrite by Acidithiobacillus ferrooxidans (A. ferrooxidans) in agar-simulated extracellular polymeric substances (EPS) media was investigated. The results indicate that bacterial EPS can release H+ and concentrate Fe3+; Fe2+ is movable between agar-simulated EPS phase and bulk solution phase, but it is difficult for Fe3+ to move due to its hydroxylation and EPS complex action; A. ferrooxidans first prefer Fe2+ as energy to metabolize compared with chalcopyrite, and a suitable simulated EPS environment for bacterial living is at about pH 1.8; the iron precipitates and jarosites formed by a lot of biologically oxidized Fe3+ cover the simulated EPS easily and form an impermeable deposit acting as a limited barrier of ion transport that attenuates the aggressiveness of the bioleaching attack. The EPS layer blocked by iron precipitates or jarosites is responsible for the chalcopyrite passivation.