Bauxite and alumina

Bauxite

Bauxite is the primary source of metallurgical-grade alumina, used to make aluminium metal, and non-metallurgical alumina, used in a range of industrial applications.

Total world bauxite production is around 300m tpy and while there are no authoritative sources for how much of this is consumed as non-metallurgical material, the fraction of raw bauxite produced for non-metallurgical applications is estimated to be 10-15m tpy.

About 80-85% of bauxite mined is processed via the Bayer Process to make alumina trihydrate (ATH), then smelter grade alumina (SGA), from which aluminium metal is derived.

The remaining 10-15% of crude bauxite is used to produce a range of non-metallurgical bauxite grades and non-metallurgical alumina grades.

The main applications for non-metallurgical bauxites are refractories, abrasives, high aluminium cements, aluminium chemicals and activated bauxite and alumina.

Other uses include filters and pigments for plastics and elastomers; special calcined aluminas for ceramics, refractories, abrasives, soft-burned calcined aluminas, hard-burned calcined aluminas for alumina cements, calcium-aluminate cements and mineral wool.

Alumina-based ceramic proppants for the fracking industry has been a significant consumer of bauxite, with production concentrated mainly in the North America and China with smaller amounts in Argentina, the Middle East and Australia, although this market has waxed and waned in line with oil price volatility.

As of 2020, the proppants market had all but collapsed to production of less than 200,000 tpy, from an estimated peak of around 1m tpy in 2014-15.

There are three main grades of non-metallurgical bauxite.

• Abrasive-grade bauxite, used to produce abrasives; 
• Chemical-grade bauxite, used to produce aluminium chemicals; and 
• Refractory-grade bauxite, used to produce high alumina refractories. 

Their characteristic chemical compositions of each grade of non-metallurgical bauxite are outlined below.

Grade	Al2O3 (%)	SiO3 (%)	Fe2O3 (%)	TiO2 (%)
Abrasive	Min 55	Max 5	Max 6	Min 2.5
Chemical	Min 55-58	Max 5-12	Max 2	N/A
Refractory	Min 59-61	Max 1.5-5.5	Max 2	Max 2.5

Source: Industry sources

Alumina

The non-metallurgical grade (also known as chemical-grade) alumina market is estimated at around 8m tpy, around 60% of which is categorised as “commodity hydrate” and used to make aluminium sulphate for water treatment, while fine grades are used as high-value flame retardants.


“Specialty” or “premium” grade aluminas, which are calcined aluminas used applications such as refractories and ceramics. Brown-fused alumina (BFA) is a widely used abrasive mineral.



Calcined aluminas are also used as feedstock for high-purity grades of tabular alumina and white-fused alumina (WFA).



Other uses include aluminium fluoride and zeolites.

Consumption

Around 1.2 million tpy of calcined bauxite is used in refractories, with a small amount also going into abrasives.


Alumina hydrate and calcined alumina are the feedstocks for alumina chemicals, WFA and BFA, with the exception of some of the very highest grades with 4N or 5N purity.



High-alumina calcined bauxite with low levels of iron and other impurities is used directly in the production of refractories, along with around 40-50% (600,000 tpy) of BFA derived from calcined bauxite.



BFA production is estimated to be around 1.2m tpy.



Approximately 70% of bauxite-based refractories are used is in the iron and steel industries, with most of the remainder being used in cement kilns and the glass industry.



The vast majority of non-metallurgical bauxite used to produce non-metallurgical alumina in China (the world’s biggest consumer of non-metallurgical bauxite) is either produced domestically, or imported from Guyana.

Application	Consumption (tpy)	Consumption (%)
Portland cement	2m	18%
Refractories	1.2m	11%
Abrasives	1.2m	11%
Iron and steel slags	800,000	7%
Chemicals	800,000	7%
Calcium aluminate cement	450,000	4%
Proppants	200,000	2%
Mineral wool	200,000	2%
Welding	60,000	>1%
Anti-skid road surfacing	10,000	>1%
Other	4m	37%

Source: Industry sources

There is a lack of clear trade data detailing the composition of global bauxite shipments, but imports of non-metallurgical bauxite into Europe, Japan and the US from China, Guyana and India are thought to be mainly refractory and abrasive grades of calcined bauxite.

The US and European countries also import raw bauxite from Greece and Turkey.

China is a large consumer of its own domestically produced bauxite, and accurate internal figures are not available.

Most non-metallurgical bauxite and alumina transactions are based on annual or longer-term contracts.

WFA has traditionally traded at a premium to BFA, owing to technical differences such as higher purity, and lower availability, however weak demand in 2019/2020 closed this price gap and decoupled price movements.

Leading non-metallurgical bauxite producers

Bosai Minerals Group (China)
First Bauxite (US/Guyana)
CMP Guizhou Co. Ltd (China)
Sky Metallurgy Mineral Co. Ltd (China)
Sinocean Industrial Limited (China)
EKW GmbH (Germany)
Imerys S.A. (France)
CUMI (India)
Demi̇reller Mining (Turkey)
Elfusa Geral de Eletrofusão Ltda (Brazil)
Elmin Hellenic Mining Enterprises S.A. (Greece)

Leading non-metallurgical alumina producers (including BFA and WFA)

ALTEO Alumina (France)
Kuhmichel Abrasiv GmbH (Germany)
Electro Abrasives (US)
HENGE-Group (Germany)
Futong Industry (China)
Washington Mills (US)
Imerys Fused Minerals (France)
Almatis GmbH (Germany)
Yichuan Shengyu Abrasives (China)
Elfusa Geral de Eletrofusão Ltda (Brazil)
Great Lakes Minerals (US)
LKAB (Sweden)

Sources: USGS, International Committee for Study of Bauxite, Alumina & Aluminium (ICSOBA), International Aluminium Institute (IAI), industry sources