GEBENG, April 22 -- Workers load tonnes of rare earth minerals into bags ready for shipping at a refinery in eastern Malaysia, fuelling the global pushback against China's grip on the critical sector.

Rare earths are a key ingredient in products ranging from smartphones to fighter jets, electric cars and wind turbines - and increasingly for hardware powering the artificial intelligence boom.

Global jitters about Beijing's dominance as a rare earths producer have kicked Australian mining giant Lynas into action, expanding its portfolio of rare earths refined in Malaysia as it hopes to boost its approximately 10 per cent share of the market.

China makes up the other 90 per cent of the world's market, stoking fears about Beijing's ability...