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.