高硅锌精矿的处理方法

介绍了处理高硅锌精矿的方法，锌精矿中的二氧化硅在焙烧时反应生成硅酸锌，在浸出时溶于硫酸溶液中，然后缓慢沉淀析出，如果工艺条件控制不当，析出的胶态氧化硅可能形成无法过滤的胶体，根据试验结果认为，应通过加速沉淀析出反应的方法，控制浸出反应槽中二氧化硅浓度≤5g/L(最佳浓度为≤2g/L)，本文提出的方法可以使二氧化硅以易于液固分离的形式沉淀，无需添置大型过滤设备，并且通过向浸出反应槽加入经预选调整SiO2含量的混合物，来控制浸出液较低的二氧化硅浓度。     

镓精矿氢氧化钠浸出过程镓的浸出行为

从湿法炼锌工艺中得到的镓精矿是制备金属镓重要的中间产品,氢氧化钠浸出镓精矿制备电积前液是制备高品质金属镓的生产关键环节。通过研究氢氧化钠浸出镓精矿过程中添加剂的种类、添加剂用量、氢氧化钠浓度、浸出液固比、反应温度和浸出时间等工艺参数,分析了各工艺参数在镓精矿浸出过程中对Ga、Al的浸出率及浸出滤液过滤性能的影响。结果表明,在添加剂为15%CaO、NaOH浓度3 mol/L、液固比L/S=10、反应温度80 ℃、浸出时间120 min的最优条件下,Ga的浸出率为98.15%,Al的浸出率为53.01%,浸出滤液过滤速度为108.88 mL/min,添加剂CaO在反应过程中生成的铝酸钙作为滤饼支撑骨架,有效改善了浸出滤液的过滤性能。     

高铁低品位硫化铅锌混合精矿氧压酸浸试验研究

研究了硫化铅锌混合精矿的氧压酸浸。试验结果表明:对100g混合精矿,在液固体积质量比3∶1、温度160~165℃、浸出时间80 min、混合气体压力0.8 MPa、搅拌速度750r/min、浸出剂硫酸质量浓度150g/L、木质素磺酸钠用量为矿石质量的0.05%、Zn2+质量浓度40~80g/L条件下,锌浸出率大于95%,铁浸出率小于10%,铅沉淀在渣中,较好地实现了锌、铁、铅的分离。     

锌精矿酸浸液H2O2法净化除铁试验研究

研究了用H2O2从锌精矿酸浸液中除铁。锌精矿酸浸液除铁工艺条件为:温度控制在90℃,溶液pH控制在3.0~4.0之间,H2O2体积分数25%,连续反应2.5 h后过滤。结果表明,滤液中铁离子质量浓度降至0.08 g/L左右,达到净化要求。     

硫化铅精矿三氯化铁浸出新工艺研究

研究了三氯化铁浸出硫化铅精矿,并在浸出后期沉淀银、铜、铋。通过试验,得出新工艺的最佳工艺条件为：三氯化铁质量浓度为140 g/L,氯化钠浓度为6 mol/L,浸出时间2 h,浸出温度90℃,沉淀剂用量为理论量的1.6倍,沉淀反应温度85℃,沉淀反应时间10 min。在此条件下,铅的浸出率达到98.41%,浸出渣中硫、银、铜、铋的富集率分别达90%,99%,98.5%,97%以上。     

湿法炼锌浸出渣与锌精矿联合浸出工艺研究

开展湿法炼锌浸出渣和锌精矿联合酸浸试验,利用硫酸浸出湿法炼锌常规浸出渣中以铁酸锌等方式存在的锌,同时采用高铁锌精矿将浸出液中的三价铁离子还原为二价铁离子,实现锌精矿中锌的同步浸出。探讨锌浸出渣和锌精矿投料比、初始硫酸浓度、反应时间、液固体积质量比和浸出温度对锌及伴生金属铜、铟和杂质金属铁浸出率的影响。结果表明,在浸出终点浸出液中硫酸浓度20～40g/L、锌浸出渣与锌精矿质量比1∶0.25、原料粒度-0.074mm、液固体积质量比6mL/g、反应温度90℃、反应时间3h的条件下,锌、铟、铜的浸出率都在96%以上,浸出液中95%以上的铁被还原为二价铁离子,满足后续工艺的要求。     

湿法炼锌浸出矿浆过滤工艺改造实践

在湿法炼锌生产过程中,当原料锌精矿品位较高时,采用传统的浓密槽进行浸出矿浆的固液分离效果较好。但近年来随着锌精矿品位的不断降低,浓密槽的分离效果越来越差,已不能满足生产需要。为此,广西某厂通过工艺改造,采用厢式压滤机代替浓密槽进行浸出矿浆的过滤,取得了较好的效果。     

贫锰矿和锌精矿同时浸出工艺研究

研究了贫锰矿与锌精矿同时浸出及以硫磺形式回收硫.通过试验,得到贫锰矿浸出锌精矿的最佳工艺条件为:始酸质量浓度150 g/L,温度90～95 ℃,液固体积质量比7∶1,贫锰矿过量1.5倍,硫酸过量1.5倍,浸出时间4 h.在此条件下,锰的一次浸出率为85.2%,锌浸出率为83.0%.     

某含多金属硫精矿焙烧—酸浸试验研究

针对某含多金属硫精矿性质,进行了焙烧—酸浸试验研究,考察了焙烧温度、酸浸硫酸用量、反应温度、液固比等因素对浸出效果的影响。结果表明:在焙烧温度600℃,酸浸反应温度80℃,液固比3. 0,终点pH=1. 0,浸出时间2. 0 h的最佳工艺条件下,获得了铜浸出率90. 65%,锌浸出率83. 87%,酸浸液质量浓度铜15. 9 g/L、锌7. 2 g/L,酸浸渣品位金29. 4 g/t、银277. 2 g/t、铁66. 58%的较好指标,为矿山工业生产提供技术支持。     

湿法炼锌中浸工艺优化试验与生产实践

锌焙砂中性浸出是湿法炼锌工艺流程的关键环节之一.通过单因素试验和正交试验考察了初始酸度、冲矿温度、浸出时间和焙砂粒度等因素对锌焙砂中浸的影响,试验结果得出较优工艺条件为:初始酸度50 g/L、冲矿温度65 ℃、反应时间60 min、焙砂粒度≤96 μm;4个考察因素均对中浸渣含锌有极显著性影响,影响由大到小为焙砂粒度＞初始酸度＞反应温度＞反应时间.某公司结合试验结果,实施了一系列技术改造:在锌精矿焙烧出料系统增加风选球磨装置,锌焙砂粒度降低至≤120 μm;在中浸双沸腾浸出槽后以串联方式增加2个100 m3搅拌反应罐,同时进行工艺流程再造.经改造前后的生产实践对比,中浸渣锌质量分数从28%~35%降低到22%~25%,中上清液质量持续稳定.      

钼蓝分光光度法测定高铁铅锌精矿中二氧化硅

文章研究了钼蓝分光光度法测定高铁铅锌精矿中二氧化硅的分析方法。该方法采用基体匹配方式校正标准工作曲线及在空白试液中加入与试样等量的Fe^3＋,有效消除了Fe^3＋的干扰。试验表明：在硫酸介质中,硅与钼酸铵生成硅钼杂多酸;用抗坏血酸作还原剂,二氧化硅标准溶液浓度在0～5．0μg／mL范围内符合比尔定律。表观摩尔吸光系数为ε=8．26×10^3L／cm·moL。方法相对标准偏差〈5％,标准回收率96．37％-104．75％。方法简单、快速,结果准确,应用于高铁铅锌精矿中0．1％-10％的二氧化硅的测定,效果满意。     

氢氧化钠循环母液杂质对高铝粉煤灰预脱硅过程的影响

以高铝粉煤灰为原料进行预脱硅,在预脱硅过程中控制氢氧化钠循环母液中碳碱浓度和氧化铝浓度,研究两种杂质成分对预脱硅过程液相成分、液相黏度和脱硅粉煤灰铝硅比变化的影响。结果表明,随着循环母液中碳碱浓度的提升,液相中的氧化硅含量稍有下降,脱硅灰的铝硅比呈小幅下降趋势,循环母液中的碳碱浓度的提升会增大液相的黏度,对过滤过程不利,应将碳碱浓度控制在10g/L以下。循环母液中的氧化铝会与脱硅液中的氧化硅反应生成羟基方钠石等沸石类前驱体,从而降低脱硅液中的氧化硅浓度和脱硅灰的铝硅比,增加脱硅灰中化合碱含量,生产中循环母液中氧化铝浓度不应超过3g/L。     

Mechanochemical leaching of refractory zinc silicate (hemimorphite) in alkaline solution

A process was developed for extracting zinc from refractory zinc silicate (hemimorphite) by mechano-chemical leaching in sodium hydroxide solution with calcium oxide added to inhibit the leaching of silica. The effects of mechanical activation, calcium oxide dosage, temperature, leaching time, liquid–solid ratio and sodium hydroxide concentration were investigated. The dissolution of silica was considerably inhibited by adding CaO, but zinc extraction was almost unchanged. Under optimum conditions in 4.5 mol/L NaOH and twice the stoichiometric CaO at 383 K, the dissolution of Zn and SiO₂ were 93.6% and 7.3%, respectively, after 1 h using a liquid–solid ratio (L/S) of 10:1.     

The hydrometallurgical treatment of zinc silicate ores

A novel hydrometallurgical procedure is described for the recovery of zinc from zinc silicate ores which have high acid-soluble zinc and silica contents. The process is conducted in a continuous concurrent manner at atmospheric pressure and temperatures of 50 to 95°C. The ore is leached with spent electrolyte from an electrolytic zinc plant to a final pH of approximately 2 to dissolve zinc and the soluble silica. The pH of the leach solution is then raised to 4 to 5.5, using a neutralizing agent, to precipitate and coagulate the colloidal silica. Finally the coagulated silica is filtered from the solution and washed. The resulting filtrate is treated conventionally for electrolytic zinc production. This process solves in a simple way the difficult problem of precipitating large concentrations of colloidal silica(e.g. 25 g SiO₂ per liter) in a readily filterable and easily washed form. The process has been tested at up to the 5 tons per day scale on ores containing willemite and on a laboratory scale with ore containing hemimorphite and smith-sonite. D.ELSNER was Formerly Senior Research Officer, Risdon Diversion, Electrolytic Zinc Company of Australasia Limited, Melbourne, Victoria, 3000, Australia.     

锌精矿降硅工艺条件试验研究与生产实践

针对乌拉根铅锌矿生产现场锌精矿含硅高的问题,进行了降低锌精矿硅含量的小型试验研究.结果表明：水玻璃对石英、长石和黏土等硅酸盐矿物具有较强的抑制和分散作用.在水玻璃、硫酸铜和丁基黄药的用量分别为300 g/t、150～250 g/t和50～80 g/t,磨矿细度为小于0.074 mm 占49.50%～54.50%,浮选浓度为37%～40%条件下,可获得锌回收率68.84%、锌品位56.16%、锌精矿硅含量为6.45%的较好指标.经生产验证：锌精矿硅含量可由11.37%降低到7.16%.     

Kinetics of sulphuric acid leaching of a zinc silicate calcine

Recent developments of acid leaching and solvent extraction of zinc silicate ores have produced renewed commercial interest. However, the leaching kinetics of these concentrates has received little attention. This work, therefore, addresses the leaching of a zinc silicate concentrate in sulphuric acid. The effects of particle size (0.038–0.075mm), temperature (30–50°C) and initial acid concentration (0.2–1.0mol/L) were studied. The results show that decreasing the particle size while increasing the temperature and acid concentration increase the leaching rate. As leaching occurs, there is a progressive dissolution of willemite while the quartz and iron-containing phases remain inert. Among the kinetic models of the porous solids tested, the grain model with porous diffusion control successfully described the zinc leaching kinetics. The model enabled the determination of an activation energy of 51.9 ± 2.8kJ/mol and a reaction order of 0.64 ± 0.12 with respect to sulphuric acid, which are likely to be a consequence of the parallel nature of diffusion and chemical reaction in porous solids.     

Sintering and ferrite formation during high temperature roasting of sulfide concentrates

The newly developed toroidal fluidized bed reactor has potential for improving sulfide roasting efficiency due to its unique and good mass/heat transfer characteristics. To achieve effective roasting at high temperature using the toroidal fluidized bed reactor, engineering issues associated with sintering and ferrite formation are investigated in this study by roasting industrial sulfide concentrates of zinc and copper. Laboratory tests are conducted at 800–1100°C by using an electric tube furnace under controlled roasting conditions. The test program is based on statistical design, and the products are characterized by XRD, SEM and EDX. It is revealed that the oxygen concentration plays an important role in promoting roasting. Roasting temperatures higher than 950°C do not favor roasting conversion due to the sintering of sulfide particles which inhibits oxygen diffusion into the particle core. Close contact of the oxidized particles favors the atomic interdiffusion between particles, leading to the formation of undesired zinc ferrite. Roasting in toroidal fluidized bed reactor results in zinc calcines with increased surface area and reduced zinc ferrite formation, thus improving zinc recovery.     

Oxidative Pressure Leaching of Silver from Flotation Concentrates with Ammonium Thiocyanate Solution

The thermodynamics and technologies of the selective pressure leaching of silver from flotation concentrates were investigated in an ammonium thiocyanate medium. Thermodynamic analyses, which include silver solubility in NH₄SCN solution and Eh-pH diagrams of the Me-MeS-NH₄SCN-H₂O system at 25 °C, were discussed. The effects of several factors, such as temperature, leaching time, oxidant, pH value, flotation concentrates concentration, surfactant concentration, and so on, on the extraction percentages of silver and zinc were investigated. The following optimal leaching conditions were obtained: NH₄SCN concentration 1.5 M, lignin concentration 0.5 g/L, Fe³⁺ concentration 2 g/L, flotation concentrates addition 200 g/L, and oxygen pressure 1.2 MPa at 130 °C for 3 hours. Under these optimum conditions, the average extraction percentage of silver exceeded 94 pct, whereas the average extraction percentage of zinc was less than 3 pct. Only 7 pct of ammonium thiocyanate was consumed after 4 cycles, which indicated that ammonium thiocyanate hardly was oxidized under these oxidative pressure leaching conditions.     

A quantitative method for silica flux evaluation

In the smelting of copper and copper/nickel concentrates, the role of silica flux is to aid in the removal of iron by forming a slag phase. Alternatively, the role of flux may be regarded as a means of controlling the formation of magnetite, which can severely hinder the operation of a furnace. To adequately control the magnetite level, the flux must react rapidly with all of the FeO within the bath. In the present study, a rapid method for silica flux evaluation that can be used directly in the smelter has been developed. Samples of flux are mixed with iron sulfide and magnetite and then smelted at a temperature of 1250 °C. Argon was swept over the reaction mixture and analyzed continuously for sulfur dioxide. The sulfur dioxide concentration with time was found to contain two peaks, the first one being independent of the flux content of the sample. A flux quality parameter has been defined as the height-to-time ratio of the second peak. The value of this parameter for pure silica is 5100 ppm/min. The effects of silica content, silica particle size, and silicate mineralogy were investigated. It was found that a limiting flux quality is achieved for particle sizes less than 0.1 mm in diameter and that fluxes containing feldspar are generally of a poorer quality. The relative importance of free silica and melting point was also studied using synthetic flux mixtures, with free silica displaying the strongest effect.     

湿法炼锌过程溶液中镍的微分脉冲极谱法测定

在氨-氯化铵缓冲液(pH=10.0)+150g/L柠檬酸钠+2g/L丁二酮肟(DMG)底液体系中,采用微分脉冲极谱法测定湿法炼锌中间溶液中镍的浓度。结果表明:在-0.98V左右产生灵敏的微分脉冲极谱波,镍浓度在8.52×10-7～8.52×10-5 mol/L范围内与相应峰电流有良好的线性关系,检测限为1.7×10-7 mol/L。该方法成功用于湿法炼锌中上清液、一段净化后液、二段净化后液、电积新液、电积废液中镍的测定,RSD分别小于等于0.43%、1.33%、1.92%、2.87%、4.87%,加标回收率为98.4%～102.2%,方法灵敏、简单、快速。