The Bayer process comprises three principal stages ( Fig. 2): bauxite digestion, aluminium hydroxide precipitation and aluminium hydroxide calcination. Cumulatively, these stages allow crushed...

 — This document will critically review existing and potential processes for the processing of high silica bauxites. High silica bauxites are usually considered to be those with reactive silica contents in excess of ∼ 8% by weight of the bauxite (reactive silica is defined later in this paper).

Bauxite is the world's principal source of aluminium and can vary from a very soft earth to a very hard rock. It can occur as red-yellow compacted earth (both friable and re-cemented), small red round pebbles (pisolites), or large pale …

Calcined Bauxite is produced by sintering high-alumina bauxite in rotary, round or shaft kilns at high temperatures. This process of calcining (heating) bauxite in kilns removes moisture and gives Calcined Bauxite its high alumina content and refractoriness, low iron, and grain hardness and toughness.

About 73% of the bauxite was refined by the Bayer process for alumina or aluminum hydroxide, and the remainder went to products such as abrasives, cement, chemicals, proppants, refractories, and as a slag adjuster in steel mills.

Processing about 4–4.5 tonnes of nepheline ore yields 1 tonne of alumina, 9–11 tonnes of cement, 0.6–0.8 tonnes of soda ash, and 0.2–0.3 tonnes of potash. According to the grade of the bauxite ore, 2–3 tonnes of ore yield one tonne of alumina and about one tonne of red mud (dry weight).

 — This paper aims at developing rational and efficient process flow charts and recommendations for improving methods for processing of bauxite with increased contents of iron and fine particles of valuable components.

 — The Bayer process is a chemical process for refining aluminium hydroxide, Al(OH) 3 from bauxite; this aluminium hydroxide is subsequently calcined to produce alumina, Al 2 O 3 . The basis of the...

In the process of calcination by vertical shaft kilns, the raw material is loaded from the top of the kiln together with coal powder and combustion improver, the fire of calcination comes from the kiln bottom, and a temperature of about 1300 – 1400 deg C is achieved in the kiln.

The most common initial process step to feed an alumina refinery with bauxite is the crushing or sizing of the raw bauxite material that is extracted from the mine. The feed material is crushed or sized so that it is conveyable, as well as correctly dimensioned, for the next step in the process.