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EPA orders rare earth mine in California to correct hazardous waste violations

The US Environmental Protection Agency ordered Molycorp Minerals, LLC, to pay a $27,300 penalty for improper management of hazardous waste at its San Bernardino County mine and mineral processing facility. The violations were discovered as part of unannounced EPA inspections in October 2012.

EPA testing at the facility determined that leaked or spilled lead-iron filter cake had impacted on-site stormwater, with the potential to contaminate soil along the edge of the holding area. A majority of the impacted stormwater was treated prior to legal disposal into on-site surface impoundments. In addition, EPA investigators found several containers holding hazardous lead filter cake were improperly closed or labeled. Subsequent to the inspection, Molycorp discontinued the operation which generated the lead-iron filter cake.

Lead-iron filter cake is the largest hazardous waste stream generated by Molycorp. Process waste containing toxic concentrations of lead are treated and solidified utilizing a filter press. That lead filter cake is transferred and stored in hazardous waste containers.

Molycorp operates a rare earth lanthanide mine, mill and separation facility near Mountain Pass, Calif. It is believed to be the only rare earth mine in the United States. Production of lanthanide (rare earths) metals at Molycorp began in 1952. The facility suspended operations in 2002 and re-opened in 2012.

When alloyed with other metals, the rare-earths can provide enhanced magnetic, strength and high temperature and other properties. For example, high-strength magnets made from neodymium-iron-boron have been used in a variety of products, including electric motors and hybrid cars components.



Unfortunately, EPA regulations on anything deemed "hazardous waste" are onerous and, IIUC, nearly prohibit any disposal other than landfilling.

I'm no chemist, but an iron-lead mess might be amenable to electrowinning or carbonyl conversion to separate the components for reuse with recovery of salable lead as a byproduct.  Maybe this is a problem that has as much of its origins in Washington as California.


Well EP, I don't think lead is that salable, electrowinnable (low electronegativity), or competitive with lead regularly mined in third world countries and passed off as paint in toys. There is a lot of low grade iron out there for the asking, and no need to get it from lead. This Molycorp mine is remote, so imagine the hauling costs.

Looks like the puny $27K fine is just a cost of doing business. There are towns that charge more for "engineering studies". New Jersey Transit supposedly wants $70K to study how to to create a "quiet zone by forcing trains not to use their bells or horns at certain intersections.

Bear in mind that rare earths and lead are usually found in agglomeration with one another because they are products of serial radioactive decay from Uranium and Thorium. You won't find them much in calcides or silicates, or other stable low atomic number elements. We just have to keep looking for more and better thorium in monazite etc.


I wasn't thinking of the process as a way to produce lead profitably.  I was thinking of it as a way to eliminate a waste stream of hazmat and maybe make a few bucks to offset costs.

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