Continuous oil and metal recovery process system for sludge and shavings


About 280,000 metric tonnes of oily grinding sludge are produced each year in the German metal processing industry. Most of the valuable and expensive metals this contains are lost because the metal sludge cannot be processed sufficiently at present: Even a small amount of adherent oil renders the metal filings unusable for recycling.

The “KOMPASS” process recovers the metals and recycles them, closing the material loop. The project partners from science and industry are focusing on metals with strategic economic importance for industry such as tungsten, niobium, vanadium and cobalt.

The innovation that removes all the oil from the metal residues is being tested in a pilot plant that can handle about 50 kilograms of material per hour. This takes place in a continuous process using water and cleaning agents. The advantages of the process: no environmentally polluting chemicals, the cleaning water is recycled, the washed-out oils are separated and, ideally, can be re-used as cooling lubricant. 

Once the method has passed its pilot test, its industrial feasibility and economic efficiency will be tested in a production plant. The plan is to operate this with an hourly throughput of up to one tonne of filings or sludge. At the end of the project, the de-oiling plants can be applied flexibly. They can be used directly on site in metal processing companies or centrally in recycling companies. The plants can be used worldwide.