含锗除尘灰中锗的选择性还原二次富集机理研究

Lignite contains higher germanium in Xiligele, Inner Mongolia. There is larger extraction of value. Now Ge extracting process included lignite drying, milling, combustion and electric power generation, at the same time collecting dust. Then the dust was distilled 2h in 9mol/L hydrochloric acid at 85-90℃. The hydrochloric acid volume is 4 times the amount of dust. The GeCl4 liquid was got. The technology of extracting Ge has the following questions: the consumption of hydrochloric acid is great; the amount of distilled residue with a lot of Ge is great because of low Ge content and high iron content in dust; Ge recovery rate is low; a large quantity of solid and liquid harmful substance was discharged. In this project Ge will be second enriched by high temperature. After enriched the Ge content in dust will increase 10 times, and the Fe content reduce 60%. The late handling capacity was reduced and the Ge recovery rate improved. The harmful emissions cut down. The component and phase of dust will be studied with XRD, ore microscope and ICP. The melting point and viscosity of dust will be measured. The Ge will be second enriched at 1500℃ after adjusted the basicity of slag and oxidation or reduction atmosphere. At the same time the enriching kinetic mechanism will be studied. The research results will provide theoretical guidance for Ge second enrichment, improved Ge extraction efficiency and reduce emission.The technology of extracting Ge will be translated from hydrometallurgy into thermometallurgy and hydrometallurgy.

内蒙古锡林格勒盟褐煤含较高的锗，提取价值大。目前提锗工艺为褐煤燃烧发电，除尘灰用9mol/L的盐酸，液固比4：1，85-90℃下蒸馏2小时得到GeCl4初蒸液。该方法存在以下问题：除尘灰中锗含量低，铁氧化物含量高，盐酸耗量大；残渣、废液量大，环境污染大，锗回收率低。项目将采用高温火法选择性还原的方法，对锗进一步富集，使富集后尘中锗含量为初始尘中10倍以上，铁氧化物含量降低60%以上，以降低后期处理量，提高锗回收率，减少有害固体和液体的排放量。项目将采用XRD、矿相、SEM-EDS结合ICP成分分析等研究除尘灰成分、矿相组成和锗的存在形态，测量其熔点和黏度，在1500℃左右温度下调整氧化还原气氛和炉渣碱度，让Ge选择性还原挥发富集，同时采用变温和恒温的方法研究该过程动力学机理。研究成果将为褐煤中锗的二次富集提供理论指导，提高锗提取效率，降低排放，把目前提锗工艺由全湿法转变为火法、湿法两步法。

内蒙古锡林格勒盟褐煤含较高的锗，提取价值大。目前提锗工艺为褐煤干燥、磨粉，燃烧发电，收集除尘灰，除尘灰锗品位仅在0.35%左右。除尘灰用9mol/L的盐酸，在液固比为4：1，温度为85-90℃下蒸馏4小时得到GeCl4初蒸液。目前该方法存在问题包括：除尘灰中锗含量低，铁氧化物含量高，蒸馏时盐酸耗量大；蒸馏后残渣、废液量大，锗含量较高，锗的回收率低；有害物排放量大，环境污染大。本项目研究了锗尘中锗的存在方式，锗尘的熔点、黏度，锗尘造球方法，高温下锗尘中氧化物间相互作用，二次火法富集工艺及火法富集过程和湿法提取过程中动力学问题。锗尘中SiO2和铁氧化物含量最高，其次为Al2O3、CaO和MgO，锗分散地存在于锗尘中的各相中；除碳后锗尘中有锗的富集相，如Mg3Fe3GeO3，并镶嵌在SiO2和CaO等氧化物中。锗尘中配入30%的氧化钙，消化时间应大于8h，消化完成后，造球机，随后自然阴干48h，能够得到性能良好的锗尘球。在高温下GeO2能够溶解于SiO2中，GeO2与CaO之间能够生成多种复合氧化物，GeO2与Fe2O3之间没有反应。SiO2会大大降低锗的回收率，CaO与GeO2间反应生成的复合氧化物不影响锗的蒸馏提取，而且CaO还能够消弱SiO2对锗蒸馏提取的不利影响，Fe2O3对锗的蒸馏提取影响不大。在空气气氛下，锗尘中碳含量为3%，碱度为1.0，在1600℃下保温1h，富集物中酸溶锗含量可达到16.65%，全锗含量为16.78%，酸溶锗的回收率达到89%以上。GeO2与SiO2形成固溶体后将大大地降低锗的蒸馏速度，而GeO2与CaO、MgO、Al2O3之间高温处理后不会影响锗的蒸馏速度。本研究获得的二次火法富集方法，可以将锗的品位稳定的提高到16%以上，品位提高45倍，相应盐酸耗量、有害废液、有害固废排放量相应降低45倍以上，提取成本大大降低，具有较大的应用前景。