Recycling Theisen Sludge from the Mansfelder Smelting Process

Research Project from the Funding Measure r⁴ by the German Federal Ministry of Education and Research (BMBF)

Theisen sludge, a by-product of the copper-slate smelting process in the region of Mansfeld in Germany, Contains metals like germanium oder rhenium.

Photo: UFZ/ Birgit Daus

So-called Theisen sludge is a by-product of the copper-slate (Kupferschiefer) smelting process in the region of Mansfeld, Germany. Between 1978 and 1990, roughly 220,000 tons of this material was deposited in waste rock piles. Apart from the main components zinc, lead, copper and tin, the sludge also contains economically valuable trace elements like germanium or rhenium. Germanium, for example, is used in fiber-optic technology and infrared optics, and rhenium is used as a component of modern alloys as well as in platinum-rhenium catalysts. The recycling of Theisen sludge has proven challenging, particularly because of its complex chemical composition that includes organic matter.

The goal of the r⁴ project is to develop a practical recycling procedure that can also be applied to similar sulfidic materials. The Theisen sludge first has to be transferred from the waste rock pile into an aqueous phase using mineral-selective bioleaching. Scientists at the Helmholtz Institute Freiberg for Resource Technology (HIF), together with their various project partners, are researching different technical approaches in order to then be able to separate and accumulate the target elements from the liquid phase. These include the process of precipitation, membrane separation, classical solvent extraction, and bio-solvent extraction with metallophores – a complexing agent for select metal ions. The main focus at HIF is the extraction of the elements germanium, rhenium, antimony, molybdenum and cobalt by means of solvent extraction.

The project „Theisen Sludge“ belongs to the funding measure „r⁴ – Innovative Technologies for Resource Efficiency – Research for the Supply of Raw Materials of Strategic Economic Importance“ in the framework program „Research for Sustainable Development (FONA)“ of the German Federal Ministry of Education and Research.

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Project title: Extracting economically relevant raw materials of flue dusts from copper production (Theisen sludge)

Project partners:

• Helmholtz Institute Freiberg for Resource Technology
• Helmholtz Centre for Environmental Research (UFZ)
• TU Bergakademie Freiberg
• G.E.O.S. Freiberg
• Biotechnology Research and Information Network AG
• adelphi research gemeinnützige GmbH
• Nickelhütte Aue GmbH

Duration: February 2015 – January 2018

Coordinated by: Dr. Birgit Daus | Department Analytical Chemistry, UFZ

Funding volume: 1,6 Mio. Euro

Funding code: 033R137

Funding measure: „r⁴ – Innovative Technologies for Resource Efficiency – Research for the Supply of Raw Materials of Strategic Economic Importance“

Funded by: