Rare earths miner Lynas expects to be producing finished products from its controversial plant in Malaysia within weeks.

The company has successfully commissioned the cracking and rare earth extraction units at its advanced mineral plant in Pahang, it said in a statement on Monday.

The units are now producing a sulphate that would be fed into extraction units for the ultimate production of rare earth products.

"Lynas anticipates commercial rare earth products will be available in the next few weeks with ramp up of production to take place over the next three months," the company said.

The Lynas plant began production in November, after long delays caused by legal action brought by opponents to its operation, who are concerned about pollution and possible health threats.

Lynas mines rare earths from the highly regarded Mt Weld in Western Australia, which are metallic elements used in products ranging from digital televisions, mp3 players and fluorescent light bulbs.