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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。 相似文献
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含锌铁钒渣的回收利用 总被引:1,自引:1,他引:0
2006年中国的锌产量超过300万t,其中约45%的锌浸出渣采用热酸浸出-铁钒除铁工艺处理,使得每年铁钒渣的产出量超过100万t〔1〕。由此总的堆存铁钒渣数量超过2000万t,并导致对环境潜在的污染。铁钒渣中平均含锌量约为6%,总的锌含量达到120万t。另外部分铁钒渣富含稀有金属如Ga、Ge、In和贵金属如Ag等,利用价值非常高。本文提出一种铁钒渣的处理工艺流程。铁钒渣首先在回转窑中焙烧得到含锌烟尘,该烟尘经过浸出-净化-电积生产锌锭。稀有金属在净化过程中回收,最后窑渣浮选得到铁精矿。低浓度SO2烟气经过除尘,吸附和解吸生产液体SO2。该技术能回收铁钒渣中所有有价金属并减少对环境潜在的污染。 相似文献
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《Minerals Engineering》2003,16(8):695-708
Effort to recover silver during the pressure oxidation requires an understanding of the behaviour of silver. In this work, pressure oxidation of silver sulphide was investigated in the temperature range of 110–150 °C and in the sulphate media. The subsequent deportment of silver was monitored to shed light on the path of aqueous silver.Silver sulphide reacts during the pressure oxidation and silver is released into the solution. Under the deoxygenated condition, aqueous silver can precipitate as silver sulphide. However, the presence of oxygen minimises this reaction and any silver sulphide precipitated is oxidised back to aqueous silver. Therefore, the major collector of aqueous silver is jarosite specie and its precipitation kinetics increases with increasing temperature and lead sulphate concentration. However, initial acidity has a negative effect on the rate of precipitation of silver and ferric ions. Silver precipitation is fast and finished before the ferric precipitation leading to the zoning of the silver in the core of the jarosite specie. During cyanidation, only the silver ion in the outer crystal planes of the jarosite is accessible to the cyanide resulting into low extraction of silver. Soluble iodide can be added to the pressure oxidation to precipitate silver iodide, which is soluble in cyanide. However, in the presence of ferric and iodide, some aqueous silver is sequenced preferentially into the jarosite and this is pronounced at high temperature because of the enhanced stability and the precipitation kinetics of jarosite. 相似文献
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《Minerals Engineering》2006,19(9):960-967
Jarosite precipitation is a very important phenomenon that is observed in many bacterial cultures. In many applications involving Acidithiobacillus ferrooxidans, like coal desulphurization and bioleaching, it is crucial to minimize jarosite formation in order to increase efficiency. The formation of jarosite during the oxidation of ferrous iron by free suspended cells of A. ferrooxidans was studied. The process was studied as a function of time, pH and temperature. The main parameter affecting the jarosite formation was pH. Several experiments yielded results showing oxidation rates as high as 0.181–0.194 g/L h, with low jarosite precipitation of 0.0125–0.0209 g at conditions of pH 1.6–1.7 with an operating temperature of 35 °C. 相似文献
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铁矾法炼锌工艺中回收银的研究 总被引:1,自引:0,他引:1
在铁矾法炼锌工艺中,溶解于溶液中的Ag~+吸附于锌焙烧料中残余的闪锌矿ZnS(0.3—0.5wt%S)表面,或生成银铁矾型化合物使银富集于酸浸渣。控制沉矾过程中焙砂的用量,保证沉矾前液清亮是降低铁矾渣中的银含量的有效措施。高酸浸出渣中的银铁矾型化合物须酸分解转化为可浮的银矿物。故从高酸浸出渣Ag(300g/t)中可用超酸浸出—硫化浮选法回收银,银的回收率76.54%,银精矿品位4456.0g/t。 相似文献