What was being mined at the Gold King Mine before the disaster?

Probably silver, mostly. I’ll keep looking.

It was an old gold mine and they use heavy metals to get the gold out. So it’s a real toxic stew.

Gold. Arsenic is used in gold mining.

Mercury is used in some mining operations. It is not to be fucked with.

The EPA screwed that one up, didn’t they.

Or the mine screwed up by not informing the EPA of what exactly was going on there.

It was a gold mine, closed since 1923.

The of the mine is the most obvious indicator of what was mined there, but as mentioned above, and arsenic is a red flag.

Gold, mainly. It is usually found in white quartz with iron, lead (galena), and silver, as well as other misc. minerals/trace metals.

@johnpowell There was no EPA when the mine was being worked.
Yes mercury was used to separate the gold from everything else. A large clean copper plate with a curled edge was coated with the mercury and water containing the crushed gold-bearing ore was allowed to wash across the plate. The water and undesirable material would run off the mercury (like water from oil or grease) but the gold would stick to the mercury and collect on the lower curled edge. After some time, the amalgamate gold and mercury were collected and placed in a wet deer or goat skin and squeezed. The excess mercury would come out of the pores of the hide and could be reused. The remaining amalgamate would be place in a kiln and heated to a high temp, evaporating the mercury and leaving the gold quite pure.

@zenvelo Arsenic is a naturally occurring substance usually found in gold and silver mines.
” Arsenic occurs as a constituent of 30 or more minerals but the principal sources are arsenopyrite, arsenides, and sulpharsenides associated with ores of lead, copper, and the precious metals, the arsenic being a by-product.” Used to make some insecticides and in some small amount, lead shot. (from HANDBOOK OF MINERAL DRESSING Ores and Industrial Minerals by Arthur F. Taggert, Vinton Professor Emeritus of Mining, School of Mines, Columbia University, Copyright, 1927, renewed 1954, of the Wiley Engineering Handbook series, John Wiley & Sons, Inc., New York – London – Sydney)

Keep in mind that a mine is a mine and a mill, where the ore is processed, is different. The toxic deluge in question is from a mine.
Gold can fairly easily be processed out of crushed ore using it’s heavy weight. Silver can be separated out using one or more mechanical contrivances, or crushed and leeched using sodium cyanide, a relatively safe technique in use today.
Smelting techniques use Borax glass to hold the impurities while the silver and other good stuff separates out like oil and water.
Point here is no heavy metals are used in the mining/milling process. All are naturally occurring and can actually cause separation problems in the milling process, especially when it comes to flotation systems using soap of some type, usually Sani-flush.

True, @kritiper. Thanks for informing us that arsenic is a by-product of mining and not something used in the extraction of gold from ore. I had confused that bit myself.

These mines, especially the old abandoned ones, have been leaching toxic metals into the rivers and water tables for over 100 years. Most of these small amounts are easily removed by normal water treatment methods. It is the magnitude of this spill that is the cause for alarm.

I read that the waterway that directly took the spill was deemed undrinkable back in the 1800’s, even before the Gold King Mine was opened, @Yetanotheruser. Yes, it’s the magnitude of the spill that’s crazy. That the EPA intentionally caused the water to collect, then unintentionally allowed it to escape.

Thanks to all. Why the writers of so many articles assume that it is obvious that it was gold that was being mined before it closed.

Uh…maybe because it was called the Gold King mine??? If it was a silver mine maybe it would have been called the Silver King mine. Jus’ sayin’...

@kritiper Hmm, How about King Gold instead of Gold King? Same thing?