Advanced gravity separation technology is going to play a major role in the recovery of valuable minerals from low-grade ores in the future.

According to National Metallurgical Laboratory (NML) director SP Mehrotra, with production of steel expected to go up in the country from 20 million tonne per annum to 120 mt in the next 7-8 years and coal output to rise to 1000 mt in the next 5 years, proper use of beneficiation technology, including gravity concentration, for recovering minerals from low-quality ores will play a vital role.

At the inauguration of a three-day national seminar on ‘Advanced Gravity Separation (AGS-07)’ at the NML here Thursday, Mehrotra said though gravity concentration had “lost its shine” around the middle of the last century with the advent of techniques like ‘floatation,’ it has come back “with a vengeance” and limitations like “small throughputs” and inability to deal with “ore fines” had been overcome.

Gravity concentration, which has been put to use for centuries now, is said to be one of the most widely used mineral separation techniques today after hand sorting.

“The kind of possibilities that are emerging are immense, and gravity concentration or gravity separation techniques are going to be some of the most commonly used separation techniques in mineral processing, coal washing, etc,” said the NML director.

With production of steel slated to rise steeply in the country, especially with the entry of companies like Posco, Arcelor-Mittal, etc, good quality iron ore (with 60% or higher Fe content), experts feel, is going to last for around 20-22 years.

Thus, to compete globally, the cost of operations, including processing of low-grade minerals, has to come down substantially.

“In a world scenario of rapidly depleting natural resources like minerals, there is no question of getting rid of tailings, discards”, said Mehrotra.

Around 75 delegates representing academia and industry from around the country are here to participate in the seminar, which will have eight technical sessions followed by a visit to an NML pilot plant on September 1, the concluding day of the seminar.

Former CIL chairman RN Sharma said mineral beneficiation has become a key area of value-addition in the current global economic situation as limited mineral resources, which are also non-renewable in nature, are seeing high worldwide consumption.

“Minerals have assumed a new dimension of importance in national economies,” said Sharma.