Context: National Aluminium Company Limited (NALCO) has successfully developed a Bauxite Certified Reference Material (CRM) naming as BARC B1201 in joint collaboration with Bhabha Atomic Research Centre (BARC).
About BARC B1201
- It is a bauxite-certified reference material (CRM).
- It is the first-of-its-kind CRM in India and the fifth in the world.
What is a Certified Reference Material (CRM)?
- CRMs are blocks of metal that come with certificates indicating the concentration of their various constituent elements along with their uncertainty levels.
- Testing laboratories use CRMs to calibrate measuring instruments, evaluate test procedures and for quality control purposes.
About National Aluminium Company Limited (NALCO)
- It is a Navratna Central Public Sector Enterprises CPSE, under Ministry of Mines, Govt. of India.
- It is country’s leading manufacturer and exporter of alumina and aluminium.
What is Bauxite?
- It is a sedimentary rock with a relatively high aluminium content.
- Almost all of the aluminum that has ever been produced has been extracted from bauxite.
- It does not have a specific composition. It is a mixture of hydrous aluminium oxides, aluminium hydroxides, clay minerals, and insoluble materials such as quartz, hematite, magnetite, siderite, and goethite.
How bauxite is formed?
- Bauxite is formed by the thorough weathering of many different rocks. Bauxite may grade into laterite or clay, laterally or vertically.
Bauxite Used for Aluminum Production
- The first step is to crush the bauxite and purify it using the Bayer Process.
- Bayer Process:
- In this the bauxite is washed in a hot solution of sodium hydroxide, which leaches aluminum from the bauxite.
- The aluminum is precipitated out of solution in the form of aluminum hydroxide, Al(OH)3.
- The aluminum hydroxide is then calcined to form alumina, Al2O3.
- Aluminum is smelted from the alumina using the Hall-Heroult Process
- In the Hall-Heroult Process, the alumina is dissolved in a molten bath of cryolite (Na3AlF6).
- Molten aluminum is removed from the solution by electrolysis. This process uses an enormous amount of electricity.
Production and reserves
- In India, Odisha alone accounts for 53% of the country’s resources of bauxite, and it is also found in the states of Andhra Pradesh, Jharkhand, Madhya Pradesh and Maharashtra.
- Australia is the largest producer of bauxite, followed by Guinea and China.