SOLUTION MINING

The advantages of microbial solution mining over conventional deep-mining are lower investment cost (particularly when the metal is being recovered from waste heaps), and increased safety, since it is bugs, not human miners, who are at risk. Moreover, conventional mining will leave roughly half the ore behind (as support pillars, for example), whereas the bugs will eat out every last niche of the sulfurous goodies. But these advantages are obviously not the merit of the bugs; they are the result of bringing the metal to the surface dissolved in a liquid, and in that respect dead chemistry can do as well as live bugs.

And it does do as well in the solution mining of uranium. Non-toxic chemicals are pumped down into underground uranium deposits to dissolve the uranium and the solution is brought up through recovery wells under slight suction pressure. A relatively small plant on the surface then precipitates out the uranium oxide and changes it to solid "yellowcake" for further processing. The uranium-free remainder of the solution is reconstituted and re-injected underground to extract more uranium, so that the path of the liquid forms a continuous loop.

This clean and environmentally benign way of mining uranium is used by Wyoming Mineral Corporation at several sites in Wyoming, Colorado and Texas, and by Nuclear Dynamics in Arizona.

Apart from producing uranium from underground deposits that would not be worth deep-mining, the method also produces it much earlier than a mine could be built. Environmental impact is minimal: WMC's plant at Bruni, Texas, including the well field, occupies less than 20 acres, of which less than half is in actual operation at any one time. As the deposits are worked out, the operation is moved to new ore bodies by lengthening the pipe lines, until at some point the plant moves up in leapfrog fashion.

[More: Contact Wyoming Mineral Corporation, 3900 S. Wadsworth Blvd., Lakewood, CO 80235.]

•	The scribblers
•	THE ENERGY BUGS
•	*SOLUTION MINING*
•	RUNNING OUT?
•	CALORIES WITHOUT THE COAL
•	A NEW APPROACH TO RISK
•	LOW-LEVEL NUCLEAR WASTES
•	GOOD READING
•	THE KEMENY REPORT

Vol. 7, No. 4

Newsletter: Access to Energy Newsletter Archive
Volume: Volume 7
Issue/No.: Vol. 7, No. 4

Date: December 01, 1979 02:56 PM
Title: The scribblers