Proof of concept to investigate a cost effective, environmentally safe closed loop system, to recover metals from spent pot liners / crucibles used in the melting of all types of metals, either during the initial smelting stage or metal purification stage

概念验证，研究成本效益高、环境安全的闭环系统，以从初始熔炼阶段或金属纯化阶段熔化所有类型金属时使用的废锅衬里/坩埚中回收金属

• 批准号: 710691
• 金额: $ 10.99万
• 依托单位: ULTROMEX LTD
• 依托单位国家: 英国
• 项目类别: GRD Proof of Concept
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=710691
• 关键词: Proof; concept; investigate; cost; effective

Spent pot linings (SPL’s) are the waste material generated in the de-lining of crucibles/potsfollowing the aluminium (and other metal) smelting electrolysis process. The SPL iscomposed of carbon & various inert elements but also fluoride and cyanide and is thushazardous waste. It is regarded as a difficult and expensive waste stream to deal with because:• It has a propensity to combine with water and generate explosive gases.• The presence of cyanide at toxic levels potentially lethal for humans and other livingorganisms.SPL's are highly regulated as a hazardous waste in most parts of the world & are subject to:• The Basel Convention on the Control of Trans-boundary Movements of HazardousWastes and their Disposal.• Increasingly onerous regulatory requirements when shipped beyond the smelter.• Bans on landfill in an increasing number of countriesEffective disposal of SPL’s from aluminium reduction cell cathodes is a significantenvironmental challenge for the aluminium industry but is also a commercial opportunitybecause of the residual metal & the potential to reuse the inert residual material for makingnew pot liners or as input for other manufacturing e.g. aggregates. Such reuse has beenunattractive previously due to the toxicity of the material.Our idea is to conduct further research with some of the novel methods we are developing formaterials separation and applying these to SPL’s. We have carried out simple tests whichshowed a degree of preferential reduction & separation of the metals. Further research &experimentation will enable us to explore these novel processes more fully for SPL’s. Wepropose that the residual, de metalled material can be treated on a Wilfley table (or similar)and with the addition of calcium hypochlorite to render the trace amount of cyanides into inertcyanites at the same time converting the fluoride to inert calcium fluoride.The inert material can then be safely re used in manufacturing.

废坩埚内衬（SPL）是铝（和其他金属）熔炼电解过程中坩埚/坩埚脱衬产生的废料。SPL由碳和各种惰性元素组成，但也有氟化物和氰化物，因此是危险废物。它被认为是一种难以处理且成本高昂的废物流，因为：·它倾向于与水联合收割机结合并产生爆炸性气体。氰化物的存在达到有毒水平，对人类和其他生物体可能致命。在世界大部分地区，SPL作为危险废物受到严格监管，并受到以下法规的约束：·《控制危险废物越境转移及其处置巴塞尔公约》。·在冶炼厂外运输时，监管要求日益繁重。·越来越多的国家禁止填埋有效处置来自铝电解槽阴极的SPL对铝工业来说是一个重大的精神挑战，但也是一个商业机会，因为残余金属和可能重新使用惰性残余材料来制造新的电解槽内衬或作为其他制造业的投入，例如骨料。由于材料的毒性，这种再利用以前一直没有吸引力。我们的想法是用我们正在开发的一些新方法进行进一步的研究，用于材料分离并将其应用于SPL。我们已经进行了简单的试验，表明金属有一定程度的优先还原和分离。进一步的研究和实验将使我们能够更充分地探索SPL的这些新工艺。我们建议，残留的脱金属材料可以在Wilfley台（或类似物）上处理，并加入次氯酸钙，使微量的氰化物转化为惰性氰化物，同时将氟化物转化为惰性氟化钙。然后，惰性材料可以安全地重新用于制造。