Coal beneficiation

Briquette factory at Niederaußem

The two key coal beneficiation technologies identified by the International Energy Agency are drying (lignite) and ash reduction (hard coal).

Coal Drying

All industrial uses of lignite require upstream fuel drying. Owing to the high amount of water to be removed, energy efficiency is of great significance here, as the process of lignite drying requires large amounts of energy.

RWE researched and developed an efficient lignite drying technology. The process, called WTA™ technology, dries lignite from more than 65% to 10% moisture. At the same time, most of the heat of evaporation is recovered. The first commercial-sized WTA™ drying plant was commissioned in 2009 at RWE’s Niederaußem power plant. RWE makes this technology available through approved suppliers and maintains the facilities for the necessary laboratory and industrial-scale drying tests.

Our WTA™-related services include:

  • opportunity studies
  • laboratory scale tests
  • industrial scale drying tests
  • basic design of your WTA™ plant

In addition, RWE Technology International supports the RWE-approved suppliers during detail engineering, construction and commissioning of WTA™ plants and in training of operating staff.

Brochure: WTA Technology (PDF | 0.8 MB)

Ash reduction

High-ash coal has been upgraded for many years by washing, that is, the removal of rocky material from the coal. Wet separation technologies, including dense media separation, have been employed routinely for years. Dry separation has recently become an alternative for specific cases.

We are independent of any ash reduction technology suppliers and co-operate with the reputable Institute for Materials Processing of the University of Aachen, Germany. Together we provide independent expert advice on the most appropriate ash reduction technology for your coal.

Our services comprise:

  • opportunity and feasibility studies
  • complete flowsheet development
  • trouble shooting and optimising in/of processing plants
  • laboratory and pilot plant tests