Nagpur institute JNARDDC invents method to make special alumina

The city-based Jawaharlal Nehru Aluminium Research Design and Development Centre (JNARDDC) has developed an indigenous process of preparing 'special alumina', which is usually imported. Special alumina, which is the precursor for manufacturing aluminium from bauxite ore, has multiple uses as fire retardants, semiconductor devices, abrasives in paints and pigments, glass, electrical porcelains, in tooth pastes etc.

The centre has developed a technique of minimizing the sodium (an impurity) levels in alumina to less than 0.1% from about 0.25% by modifying the conventional process. This has increased its value by seven to ten times. The centre is waiting for a patent of the process, so it has not shared full details of the process.

However, JNARDDC director Anupam Agnihotri told TOI that special alumina was being imported and prepared by technology not available in India so far, but the centre has modified certain parameters in the existing process to make it much simple.

"Actually, most of the bauxite ore is converted into metal or aluminium (90%) using a scientific method called as Bayer's process, while 10% of it is converted into material called as alumina, which has special applications," he said.

The project has been supported by the ministry of mines and the science and technology ministry. A team of scientists led by Suchita Rai in the aluminium division at JNARDDC, and comprising MT Nimje and MJ Chadda, worked on the project. "Though we have modified the process as per the need of Indian industry, we need to improve on certain steps to make it a very effective process. It can thus be used for setting up low capacity alumina plants near small bauxite deposits," said Rai.

She added that the JNARDDC team could maintain existing yield levels of alumina production as well as add value to the existing product, which is imported fully currently. Hence, it will help the country save a large amount of foreign exchange.

The alumina production process does not require any special refinery hence alumina production can also help the aluminium industry survive the ongoing global recession. Alumina has wider applications compared to aluminium. Manufacturing alumina on large scale is now possible using this technology.

The scientists tried various permutations and combinations of modifying different parameters that go into making of alumina to arrive at the present process. With some more modifications, JNARDDC will be able to offer the Indian aluminium industry a very viable and cheap alumina manufacturing process. But it is still in the process of evaluating the energy use and validation of the process.