New extraction process for recovery of metals in glass deposits
New extraction process for recovery of metals in glass deposits
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回收玻璃沉积物中金属的新提取工艺
DOI：
10.15626/eco-tech.2014.020
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
O. Grinder
中科院分区：
文献类型：
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作者：
S. Seetharaman;O. Grinder
已经开发了一种新的工艺，称为盐提取工艺，能够从二次来源，例如废料和废物，如炉渣和烟道粉尘中回收金属价值。在从某些通常难以用传统冶金法富集和加工的矿石中提取金属方面也是可行的，例如镍和钴。盐萃取法还应用于从硅酸盐中回收金属，包括从玻璃废料中回收铅。该工艺是基于从原料中提取金属值到熔盐浴中，熔盐浴由NaCl， LiCl和KCl组成，对应于三元共晶成分，溶解在盐熔体中的AlCl 3作为氯化剂。然后在同一个反应器中电解盐浴。正常的加工温度范围是973 K（700℃）到1173 K（900℃）。盐浴中的氯化铝与细粉碎原料中的金属发生反应，在氯浴中形成金属离子。在电解过程中，金属离子到达固体阴极并以金属形式沉积。液态铝用作阳极。在阳极处形成的氯气与铝反应形成原位氯化铝，氯化铝溶解在盐熔体中，提供所需的助熔剂量。盐萃取法已成功应用于从电弧炉硅酸盐渣中提取铬和铁。还进行了从废阴极射线管中高收率回收铅的实验。该工艺成功地从永磁体废料中提取出稀土金属钕和镝。该方法是一种很有前途的回收战略金属的工艺路线。它还具有环境友好的附加重要优势，只有少量可回收，潜在有用的剩余产品，如氧化铝和二氧化硅，能源消耗有限。
A new process, named salt extraction process, has been developed to enable recovery of metal values from secondary sources e.g. scrap and waste materials such as slag and flue dust. It is also feasible in extracting metals from certain ores that normally are difficult to enrich and process by traditional metallurgy – two examples are nickel and cobalt. The salt extraction process has also been applied in the recovery of metals from silicates including lead from glass wastes. The process is based on the extraction of metal values from the raw materials into a molten salt bath consisting of NaCl, LiCl, and KCl corresponding to the ternary eutectic composition and with AlCl 3 dissolved in the salt melt acting as the chlorinating agent. This is followed by the electrolysis of the salt bath in the same reactor. The normal processing temperature is in the range 973 K (700 ° C) to 1173 K (900 ° C). The aluminium chloride in the salt bath reacts with the metals in the fine comminuted raw material and metal ions are formed in the chloride bath. During the electrolysis, the metal ions reach the solid cathode and get deposited in metallic form. Liquid aluminium is used as the anode. Chlorine gas formed at the anode reacts with aluminium forming aluminium chloride in situ , which gets dissolved in the salt melt supplying the required amount of the flux. The salt extraction process has been used successfully in the extraction of Cr and Fe from electric arc furnace (EAF) silicate slag. Experiments have also been carried out in which lead has been recovered with high yield from spent cathode ray tubes. The process was shown to be successful in the extraction of the rare-earth metals neodymium and dysprosium from permanent magnet scrap. The method is a highly promising process route for the recovery of strategic metals. It also has the added important advantage of being environment-friendly, with only small amount recyclable, potentially useful rest products like alumina and silica as with limited energy consumption.