California Borate Company property, Kramer Borate deposit, Boron, Kern County, California, USAi

Regional Level Types
California Borate Company property	Property
Kramer Borate deposit	Deposit
Boron	Town
Kern County	County
California	State
USA	Country

I'm not sure what this mine should be called now because it doesn't exist any more except for perhaps some water filled backfilled stopes some hundreds of feet deep slightly to the south of the big open pit borate mine at Boron, California.

To my knowledge, no gerstleyite was ever found in the pit (The big open pit mine at Boron).

The Western mine was owned by Mudd, Mudd, Mudd, & Dub, otherwise known as the Kern County Land Co. (early owners of the Thompson mine in Furnace Creek). The Western passed into the hands of American Potash and thence onto Kerr McGee. (US) Borax bought the Western about 30 years ago from Kerr McGee for $10mm, but literally had to get an act of Congress passed to overcome the antitrust consent decree.

The Western shaft was demolished nearly 20 years ago. The pit south rim is now 1/4 mile south of the shaft site. The Western was virtually mined out by 1950 with sand stope filling to maximize recovery. The Western property boundary was a nuisance to Borax; Borax needed the property because 40mm tons of its own reserves were lost if they couldn't be mined by open pit with the pit walls on Western property. Two-thirds of the ores remaining at Boron are kernite, located in the deep southeastern portion of the deposit (stripping ratio ~30:1!). Borax is spending north of $150mm to do process plant construction for the direct feed of kernite to the primary (hot water) process plants.

I drilled several core holes within the Western ore block in attempts to get complete lake bed & ore intercepts by targeting the underground pillars. We missed the pillars in a couple of holes, but still brought up sodium borate mush in the core barrel from what was a kernite ore stope. We concluded that because the workings were flooded from more than 50 years previous, the openings had swollen shut due to hydrating kernite (the Western shafts had static water levels at 300' below surface at the time & the workings were at 800' depth).

Operations at Boron are now known as Rio Tinto Minerals. Boron essentially abandoned separating the calcium borates nearly 20 years ago when they converted to bigger equipment and from 25' to 50' mining faces. Previous Ca stockpiles ran about 11% B2O3. Current stockpiling attempts apparently run about 5%, hopelessly short of any economic separation. The earlier stockpiles contain, I believe, about 30mm tons of Ca borates, not enough to warrant the expensive processing.

Twenty years ago, Borax produced perhaps 60% of the world's borate products; Today that production may be about 30%. At last count, the Turkish deposit at Kirka contained in excess of 600,000,000 tons of borax, more than 3x the size of the original deposit at Boron. Needless to say, Turkey will control the future of borates. By the way, Bigadic is calcium borates.