ALExx / Laboratory Tumbling Digester

ALExx / Laboratory Tumbling Digester – The Definitive Alumina Extractor for the Aluminium Industry


How It Works

The commercial value of bauxite deposits and bauxite shipments is determined by the amount of alumina that can be extracted under Bayer plant conditions. Methods used for alumina extraction often consist of open flames, hot oil baths or air convection ovens, which are often dangerous, inefficient or very expensive.

STAS has commercialised a safe, reliable, cost‑effective alumina extractor that simulates alumina extraction in the laboratory: the ALExx / Laboratory Tumbling Digester. This high performance tumbling digester is used for pressurized caustic extraction of alumina minerals. It is able to accept up to sixteen 45 ml ParrTM pressure vessels containing caustic and bauxite slurries. ALExx can be successfully used in other caustic extraction applications, such as the pulp and paper industry with its black and Kraft liquors, or in any mineral process where caustic extraction is required.

“The Definitive Alumina Extractor for the Aluminium Industry”

Key features



  • Constant tumbling action and numerous heating elements, which makes the process safe and efficient.
  • Temperature control.

  • Precise digestion temperature, agitation and duration.

  • Caustic extraction of bauxites, red muds and a variety of other minerals.