Molycorp announced that it had passed a major milestone when it initiated the start-up of its new mill, flotation separator, and paste tailing facility at its flagship Mountain Pass, CA on May 10.

The mill will run for three weeks and will produce a large amount of concentrate for processing. Molycorp then plans to pause milling in order to further optimize the process. “The entire concentrate circuit will run intermittently between now and continuous Phase One operations, which is slated at the beginning of the fourth quarter of this year,” said Molycorp chief executive officer Mark Smith.

Over the next six months Molycorp plans to complete construction, testing and commissioning of a full-size, multi-stage cracking facility; solvent exchange and heavy concentrate production; rare earth oxide separations; full scale operations of a combined heat and power plant; and product fishing.

“This technology can be put to use very quickly, as we have been producing and stockpiling a heavy-rare earth concentrate stream ever since we launched NFP separations at Mountain Pass,” he added. “We currently have tons of this concentrate at Mountain Pass. With Neo, we will have the ability to again process this concentrate almost immediately into ultrahigh-purity heavy rare-earths products.”

During the first quarter Molycorp also announced a 36 percent increase in proven and probable reserves at Mountain Pass, which equates to 2.94 billion lbs of contained REO equivalent in the ground or more than 1.3 Mt (1.4 million st).

Mountain Pass produced 615 t (634 st) of REO-equivalent product, down from 730 t (805 st) during the first quarter of 2011. Molycorp COO James S. Allen told analysts, “We slowed production during the quarter to manage inventory levels both for finished product inventory and of rare earth concentrate stockpiles”"

“Our goal remains to ensure Project Phoenix Phase 1 production rates commence at the beginning of the fourth quarter this year,” Smith said. “We are also reaffirming that we expect to reach our 2012 production guidance range of 8 kt to 10 kt (8,000 to 11,000 st) of REO equivalent products across all of our operating segments this year.”

Also during the first quarter, Molycorp Silmet reported production of 410 t (452 st) of REO equivalent as well as 170 t (187 st) of specialty metals (niobium, tantalum).