热酸浸出—铁矾法炼锌工艺中富集锗的研究

进行了“热酸浸出—铁矾法炼锌工艺中锗和银的富集和回收”的实验室扩大试验 ,在 10个循环试验中 ,工艺流程畅通 ,以黄钾铁矾沉铁代替通常的钠或铵铁矾沉铁使锗在矾渣中的损失减少到 5 0 %以下 ,锗和银均富集于高酸浸出渣中 ,其品位分别为 0 0 32 5 %和 0 16 2 %.     

热酸浸出-铁矾法炼锌工艺中富集锗的研究

进行了"热酸浸出-铁矾法炼锌工艺中锗和银的富集和回收"的实验室扩大试验,在10个循环试验中,工艺流程畅通,以黄钾铁矾沉铁代替通常的钠或铵铁矾沉铁使锗在矾渣中的损失减少到5.0%以下,锗和银均富集于高酸浸出渣中,其品位分别为0.0325%和0.162%.     

从锌冶炼渣中回收银的试验研究

某锌冶炼渣含高品位银360 g/t, 银在浸出渣中的形态比较复杂, 且绝大部分银被黄钾铁矾包裹, 回收困难。根据浸出渣性质进行了试验研究, 最终采用焙烧浸出除铁、焙烧浸出渣浮选富集银, 得到的银精矿品位为3 899 g/t, 银回收率为88.09%, 实现了资源的综合回收。     

锌浸出渣水浸预处理-分段硫化浮选回收银工艺研究

湿法炼锌企业每年产生大量锌浸出渣,直接渣场堆放会导致严重的环境问题和矿产资源浪费。开展浸出渣中银经济高效回收工艺研究对最大程度提高资源利用率具有重大意义。某锌浸出渣中有价金属银嵌布粒度细、银赋存形态复杂且水溶锌含量高。为回收浸出渣中的有价金属银,降低水溶锌对含银矿物浮选的不利影响,开展水浸-分段硫化浮选回收银工艺研究。结果显示：水浸后锌浸出率达38.3%,银品位提升至205g/t,水浸-浮选试验银精矿回收率相较于直接浮选可提高8%,再通过快速浮选-两粗两精一扫的闭路浮选工艺获得银精矿1#银品位为4128.19g/t、银回收率62.17%,银精矿2#银品位为1101.56g/t、银回收率18.19%。XRD、EPMA及EDS分析结果表明,银精矿中银主要分布于石膏、硫酸铅、铁酸锌及闪锌矿等矿物中。     

锌浸出渣浮选银的预处理研究

在锌精矿的沸腾焙烧过程中,温度高于650℃时,生成的氧化锌及氧化铁结合成铁酸锌,是一种难溶于稀硫酸的铁氧体,全部留在浸出渣中。高温高酸浸出条件控制愈好,铁酸锌被溶解的愈多,硫化锌被破坏的就愈彻底,渣含锌就愈低,金属回收率就愈高,而且有利于银的浮选。针对某冶炼厂湿法炼锌渣,采用高温高酸浸出和浮选的方法回收锌、银,高温高酸浸出液经过除铁得到的溶液返回锌系统回收锌,高温高酸浸出渣经过一次粗选两次精选三次扫选的试验流程,得到了品位达到了2017.45g/t,回收率达到78.44%的银精矿。     

提高黄钾铁矾法炼锌中银回收率的探讨

本文分析了银在焙烧、浸出和沉矾过程中的行为。铁矶渣中95%的银来自沉矾中和剂焙烧料。采用低污染黄钾铁矾法是提高银回收率的有效途径。     

碱性焙烧再次沉矾法回收黄铁矾渣中的铟

从湿法炼锌的富铟铁钒渣中回收海绵铟.将黄铁矾渣碱性焙烧、稀酸浸出、再次沉矾、二次铁矾渣经焙烧、酸浸、还原可得海绵铟.主要考察了铁钒渣650℃焙烧时的碱渣配比、焙烧时间,焙烧渣浸出温度和再次沉矾时间等因素的影响.结果 表明,碳酸钠和黄铁矾渣的质量比为0.36,焙烧90 min后,用1 mol/L稀硫酸在85℃C下浸取150 min,浸出液在90℃下经14h再次沉矾,铟含量可提高23倍.二次矾渣600℃C焙烧后用1.0 mol/L稀盐酸浸出,浸出液直接用铝板置换,可得到93％以上的海绵铟,铟的直收率85％.     

采用锌冶炼窑渣处理污酸回收铜铁技术

针对锌冶炼系统产生的污酸成分复杂、酸度高,砷及重金属浓度高的特点,利用湿法炼锌过程中产生的含有大量有价金属的回转窑渣对其进行处理。提出了"污酸浸出锌窑渣—常压臭葱石合成法沉砷—铁粉置换沉淀铜、砷—中和水解—赤铁矿法沉铁"的主体工艺,在实现污酸无害化处理的同时有效利用窑渣中的有价金属资源。结果表明,经二段逆流浸出后,铜、铁、锌的浸出率均在90%以上,砷的沉淀率高于95%,沉砷渣为晶型良好的臭葱石。溶液中铜的沉淀率超过99%,实验得到的赤铁矿渣含铁量达64.42%,可作为炼铁或制作铁红的原料。     

高温高酸浸出渣浮选银工艺研究

某厂高温高酸锌浸出渣含银401.6 g/t、锌3.37％、铅20.41％、硫12.52％.分析浸出渣的性质和银的物相,研究用硫化钠预处理渣,加入丁基黑药和乙硫氮组合药剂来提高银浮选指标.锌的浸出渣经过一次粗选、两次精选及三次扫选流程,得到了银品位为2017.45 g/t、银回收率达到78.44％的银精矿.     

锌冶炼污酸与窑渣联合处理工艺研究

针对锌冶炼系统产生的污酸成分复杂、酸度高，砷及重金属浓度高的特点，利用湿法炼锌过程中产生的含有大量有价金属的回转窑渣对其进行处理。提出了“污酸浸出锌窑渣-常压合成臭葱石法沉砷-铁粉置换沉淀铜、砷-中和水解-赤铁矿法沉铁”的主体工艺路线，在实现污酸无害化处理的同时有效利用窑渣中的有价金?属资源。结果表明：经二段逆流浸出后下铜、铁、锌的浸出率均在90%以上，砷的沉淀率高于95%，沉砷渣为晶型良好的臭葱石。溶液中的铜沉淀率超过99%，实验得到的赤铁矿渣含铁量达64.42%，可作为炼铁或制作铁红的原料。     

Enhanced leachability of gold and silver in cyanide media: Effect of alkaline pre-treatment of jarosite minerals

Composite samples of tailings containing gold (1.35 g/t) and significant amounts of silver (155 g/t) were subjected to batchwise cyanide leaching to assess the feasibility of extracting gold and silver. The tailings are waste solids arising from flotation and leaching operations whereby the flotation product (sphalerite concentrate) is calcined and then solubilised into dilute sulphuric acid solution and eventually sequestered from the electrolyte by electrowinning. Silver and gold are part of the zinc refinery residue, flotation tailings and to a limited extent the calcine leach tailings. Mineralogical results showed that composite tailings are refractory in nature (44% quartz, 17% silico aluminates and 12% jarosites).The concept of enhancing gold and silver recovery from the tailings focused on firstly decomposing the jarosite minerals by alkaline pre-treatment and then secondly leaching with cyanide solution. These two steps ensured that free gold and silver found in the zinc refinery residue and in the jarosite minerals could be leached simultaneously. The composite tailings were treated with Ca(OH)₂ solutions and then heated to 90 °C for 2 h to decompose the silver-bearing mineral (Ag,PbFe₃(SO₄)₂(OH)₆). The alkaline pre-treated tailings were then subjected to cyanide leach tests at different NaCN dosages (2.5–10 kg/t) and particle size (96–200 μm). Without an alkaline pre-treatment stage, leach efficiencies achieved were 41% and 25% for gold and silver, respectively at 40 °C and 8 h mixing time. But, better leach efficiencies (55% for Au, 81% for Ag) were achieved after the feed was pre-treated with Ca(OH)₂. The leaching mechanism of gold was explained by the shrinking sphere model denoted by surface chemical reaction.     

湿法炼锌浸出渣湿法和火法联合处理工艺

为了综合回收锌浸渣中的有价金属,进行了弱酸渣酸浸减量化研究,减量后的渣进回转窑处理,酸浸混合液采用锌精矿还原处理－铁粉置换沉铜－锌焙砂预中和－氧化锌粉中和沉铟工艺来分离回收有价金属。采用酸浸工艺和回转窑工艺联合处理锌浸渣,可减少入窑渣量,降低能耗。结果表明,锌浸渣经酸浸可减量50%以上,锌粉中和沉铟工艺可实现锌回收率大于90%,铜回收率大于99%,沉铟后液铟小于5 mg/L。减量后的渣可富集铅、银等金属,该渣送回转窑挥发处理,产出的氧化锌烟尘可用于中和沉铟,中和过程既可使氧化锌中的锌预先浸出,又可进一步富集铟。该工艺可实现锌浸渣的无害化处理和资源综合利用。     

某高砷高硫金精矿焙砂浸金特性的研究

某高砷高硫金精矿焙砂含Au 84.27 g/t, 含As 0.55%、S 1.03%, 生产现场金的氰化浸出率不足80%, 迫切需要查明该焙砂的浸金特性。结合化学成分和物相分析, 发现含铁物相包裹是浸金渣中残留金难以浸出的根本原因。浸金渣残留金(19.54 g/t)中包裹金占96.66%, 主要包裹物相有氧化铁、毒砂和黄铁矿等含铁物相, 92.68%的包裹金存在于这些含铁物相中。浸金试验中焙砂及浸金渣所达到的浸出率分别只有84.47%、16.70%, 进一步验证了含铁物相中的包裹金极难浸出, 焙砂的浸金率很难继续提高。     

Zinc and silver recoveries from zinc–lead–iron complex sulphides by pressure oxidation

Acid pressure oxidation followed by cyanide leaching of the residue is a promising process for the treatment of complex sulphides and the recovery of precious metals along with the base metals will improve the economy of the process. However, silver is incorporated into the jarosite specie during the pressure oxidation and cyanide leaching of the residue yields very low silver extraction.In this work, iodide was added to the pressure oxidation of zinc–lead–iron complex sulphides to prevent the deportment of silver ions into the jarosite phase. At low temperature range (110–130 °C), the silver ions were completely sequenced into the silver iodide phase because of the fast precipitation kinetics of silver iodide and its stability at low temperatures. The leaching of the residue in cyanide solution yielded high silver extraction (above 90%).Silver extraction from the residue decreased when the pressure oxidation was conducted at high temperatures (140–150 °C). At this temperature range, the enhanced stability and the precipitation kinetics of the jarosite specie posed a challenge by competing (with iodide) for silver ions. This competition was minimised by using moderately high initial acid for the pressure oxidation.High zinc extraction was achieved during the pressure oxidation. Also, there were appreciable iron precipitation and acid neutralisation of the slurry. The resulting pregnant solution is suitable for zinc recovery by electrowinning and the residue can be leached for silver and gold extraction.     

铁矾渣直接还原-浮选回收银工艺研究

采用直接还原-浮选新工艺流程回收铁矾渣中的银。结果表明,银矿物被包裹在铅铁矾矿物中难以充分解离,直接浮选效果不理想;通过直接还原反应可以破坏铅铁矾矿物的化学结构从而使包裹银暴露易于硫化,同时降低锌含量,避免Zn²⁺对浮选的不利影响。直接还原-洗矿-浮选闭路流程得到银品位2 125 g/t、回收率80.35%的银精矿,浮选效果良好。     

Investigating heap bioleaching: Effect of feed iron concentration on bioleaching performance

This paper describes an investigation into the effect of iron concentration in the leach solution on the bioleaching of a low grade copper ore, where chalcopyrite was the dominant copper sulphide. The concentration of dissolved iron is primarily controlled by pH and the relative proportion of ferric to ferrous iron, with significant jarosite precipitation occurring above pH ≈ 1.8 in a highly oxidised system. The solution pH may be increased by the dissolution of acid soluble gangue and when iron oxidation is significantly higher than sulphur oxidation. The study was approached using two experimental systems. In the former, the leach solution was recycled through an ore bed of low aspect (reactor height divided by diameter) ratio for a portion of the experiment. During the recycle phase, no acid was added to the system and acid consumption by gangue material led to a pH increase (1.6–2.2). The resulting jarosite precipitation reduced soluble iron from 2.5 g/l to less than 250 mg/l. Copper recovery decreased, but not in proportion to the decrease in iron. This was partly attributed to adsorption on, or entrainment within, the jarosites. To study the effect of reduced iron concentration on leach performance under more controlled conditions, bioleaching was performed in packed bed column reactors with feed iron concentrations ranging from 5 g/l to 200 mg/l. Observations indicated an initial decreased rate of copper liberation with reduced iron concentration in the feed. The relationship between available Fe³⁺ concentration and copper liberation was not proportional. However, with time, the liberation of copper became independent of iron concentration in the percolation liquor. Further, the specific rate of copper liberation was consistently below the theoretical value on a basis of ferric iron concentration. The highest values of copper liberation were reported at the lowest iron concentrations. In summary, while increased iron concentration in solution may enhance the initial rate of leaching, mineral availability appears to dominate CuFeS₂ leach kinetics through the majority of the leach. Furthermore, high iron concentrations in solution aggravate jarosite formation with concomitant retention of copper in the ore bed.     

提高硫酸化焙砂中金和铜浸出率的研究与实践

为了提高硫酸化焙砂中金和铜的浸出率,降低尾渣金品位,减少铜对氰化浸出过程的影响,考察了焙砂粒度、硫酸浓度、温度对硫酸脱铜率和脱铜渣氰化浸金率的影响。结果表明,焙砂(矿粉粒度-0.045 mm粒级占90.16%)在酸度25 g/L、液固比1.5∶1、80 ℃下浸出2 h,硫酸脱铜率达93.62%。脱铜渣在NH₄HCO₃用量10 kg/t、液固比1.5∶1、NaCN浓度0.10%条件下浸出60 h,金浸出率高达98.04%。根据研究结果,通过提高硫酸脱铜温度、硫酸浓度和氰化浸出过程增加旋流器和浸出槽数,采用两段浸出-两段洗涤措施,对现有生产流程进行了优化,铜和金回收率得到了明显提高,获得较好的经济效益。