What is the process of mining aluminum?

What is the process of mining aluminum?

Extraction of aluminium metal takes place in three main stages¿mining of bauxite ore, refining the ore to recover alumina and smelting alumina to produce aluminium. Bauxite is mined by surface methods (open-cut mining) in which the topsoil and overburden are removed by bulldozers and scrapers.

What is the process of bauxite mining?

The ore must first be chemically processed to produce alumina (aluminum oxide). Alumina is then smelted using an electrolysis process to produce pure aluminum metal. The ore is acquired through environmentally responsible strip-mining operations. Bauxite reserves are most plentiful in Africa, Oceania and South America.

How is alumina extracted from the bauxite ore?

Alumina refining produces alumina (Al 2 O 3) from the bauxite ore, by exploiting the reversible reaction of the Bayer process 1–3: The reaction is firstly driven in the sodium aluminate (NaAlO 2) direction by the addition of caustic soda (NaOH) to bauxite. Bauxite residues are then removed, leaving the process liquid, termed “green liquor.”

How is the processing of bauxite a simple process?

Unlike the base metal ores, bauxite does not require complex processing because most of the bauxite mined is of an acceptable grade. Ore quality can be improved by relatively simple and inexpensive processes for removing clay, known as “beneficiation”, which include washing, wet screening and mechanical or manual sorting.

How many tonnes of bauxite are mined each year?

Crushing and sorting. Washing and beneficiation (further treatment of the ore to concentrate the minerals) if necessary. Delivery to export or to local refineries. Approximately 165 million tonnes of bauxite are mined each year. Bauxite is generally transported to refineries by conveyor, rail, or ship.

What kind of aluminium is used in bauxite?

While demand for bauxite is expected to grow as demand for high quality aluminium products increases, new reserves will be discovered or become economically viable. Gibbsite is an aluminium hydroxide (Al (OH)3), while böhmite and diaspore are both aluminium-oxide-hydroxides (AlO (OH)).