A CSIC team has developed a method for recovering high value-added bismuth from the waste generated in primary copper production, which includes an integrated removal of the arsenic present. The process contributes to economic and environmental sustainability.
Different bismuth crystals. Author: Alchemist-hp/ Wikimedia
Bismuth is one of the critical raw materials with a significant impact on various industrial sectors. Its scarcity at European level leads to high external dependence and a considerable risk of supply shortages, similarly as it happens with other scarce raw materials.
Bismuth, a non-toxic and environmentally friendly metal, is used in a wide range of applications, from pharmaceuticals and cosmetics to coatings and fusible alloys, replacing harmful metals such as lead. However, its extremely low recycling rate (1%) highlights the urgent need to develop technological solutions based on secondary sources to meet the growing demand.
A team of CSIC researchers has developed a method for the selective recovery of bismuth in the copper smelting industry. In this industry, a concentrate ore is used to obtain high quality copper, a concentrate that is the result of crushing and treating the ores extracted from the mines (which have a low concentration of copper).
The copper content in the concentrate ore is around the 25-30%, and the rest are different minerals or waste materials. The concentrate goes through different stages to separate this percentage of copper from the rest of the elements, to finally arrive at a high purity copper. One of these stages is the converter, where the copper is separated from the traces of sulphur, iron and other metals present, including critical raw materials such as bismuth.
In the method developed by the CSIC team, the converter dust undergoes a physico-chemical process to separate the bismuth for revaluation. At the same time, the arsenic present is removed, thus minimising the environmental impact of this industrial activity.
As an advantage, a high added value is provided to a circular economy process, which allows the commercialisation of resources obtained from secondary sources. It is a tool that can contribute to securing the supply of bismuth, in the form of bismuth oxychloride. It also helps to reduce the environmental impact and waste management costs of industrial activities.
Contacte:
Dra. Isabel Masip
Vicepresidencia de Innovación
y Transferencia del CSIC