Mines

Mining, critical minerals, and environmental impacts.

Mines.

        The Mojave Desert has been littered with many different types of mines over the past centuries. Massive scale faulting of the region has made it easier for hydrothermal and magmatic mineral intrusions to become prevalent, and thanks to the aridness of the region, it has made mine sights easier to find. Mining in the Mojave dates back to the 1800’s when trail blazers would come to seek a fortune in mining claims, unfortunately not all mines succeed. Mines require an incredible amount of work to maintain: large scale equipment, time, and most importantly water are all needed; the presence of water usually determines if a mine succeeds or fails. Most mines in the Mojave today are large-scale open pit mines that supply a large percent of, not just the nation, but the entire world with important minerals.

Boron Mine

        During our trip, our team visited the Boron mine at Boron, CA, which is run by US Borax and Rio Tinto. Boron is commonly used in glass, fertilizers, detergents, and many more things, and is even sold in bags at stores, and this specific site produces about 30% of the world’s Boron. At this site, they specifically produced Tincal, kernite, ulexite, and colemanite, all which are different types of Boron, and are currently finding ways to mine Boron at their site and remedy the main other things they have mined to get to the Boron. At the site they told us a little bit about the history of the mine, and allowed us to go down into the mine and pick our own pieces of Boron to take home with us. They especially let us collect our own pieces at Boron at two of the different smaller sites in the giant boron mine pit. 

Mountain Pass Mine

At our time in the Mojave Desert, we visited the Mountain Pass Mine. This mine is owned by MP Materials and supplies 15.8% of the world’s rare-earth elements. It is the only rare-earth element mine located in the U.S. They provide minerals that can be used for automotive, clean energy, military, and digital technologies. At the moment, all of the minerals are shipped to China for processing. The U.S Department of Defense funded the company to build a processing facility to produce rare earth products in the U.S.

After a brief presentation from our tour guide, Lin, we were able to travel down into the mine and look at the various minerals and how they extracted the ores. While on the way down into the mine, we saw a crew setting up explosives for later that day. They use explosives to break up the rocks, then use huge trucks to extract them out of the mine and into an area for crushing. The crusher was a machine that reduces the size of the rocks and ores in order to be processed. We were able to see the process of rare earth mining from when the ores are embedded in the rock, to when they are stored for processing.

Vulcan Mine

Vulcan mine is an old open pit iron mine found near Kelso, California. It was opened by the Kaiser Steel Company in 1942 and provided a primary source of raw iron to be processed into ores for the war effort. At peak production, Vulcan Iron Mine was producing 2,500 tons of ore per day, which was then shipped to the west coast via the Kelso train depot. Ore was used for steel production, which aided in the war effort at the time. Kaiser company steel was mostly used for ship building on the west coast. WWII Victory and Liberty warships were being assembled with the steel plates. The mine closed in 1948 after higher grade and more easily accessible iron ore was found at Eagle Mountain. The iron at Vulcan mine was high in sulfur which made it more difficult to process and thus less economical. The main ores being extracted were hematite, magnetite, and limonite. The Vulcan Mine and Kelso train depot are no longer operational, but both remain open to visitors. During our tour of the Vulcan Mine, we were surprised to see how much iron was produced from such a small area and wondered at how much effort must have been put into extraction, shipping, and processing. 

Other Mines

Castle Mountain

Castle Mountain is an open pit heap leach gold mine located within San Bernardino county (Lat/long: 35.28472, -115.10028) about 75 miles away from Las Vegas. Castle mountain is a mountain in the castle mountain range, a small range extending North-Northeast in the eastern Mojave Desert. The range’s base is made up of metamorphic and plutonic rocks from the Proterozoic era. The metamorphic rocks are made up of biotite, schist, meta granite, and conglomerate with lesser sandstone. There are also sequences of volcanic and epiclastic rocks from the Miocene period. From 1992-2004 1.3 million ounces of gold was mined, until the mine closed, with 4 million oz remaining. In 2019 it reopened and started its phase 1 development and expansion, predicted to produce 25,000-35,000 oz of gold.

Panamint Valley

The Panamint Valley Lithium Mine is one of two active lithium sites in the United States. The only other active site is in Clayton Valley, near Silver Peak, Nevada. We did not get the opportunity to visit either of these sites. The Panamint Valley Lithium Mine is located near the Sunrise Canyon Wilderness Area and the China Lake US Naval Air Weapons Station. Battery Mineral Resources, an Australian based company, has four claims to public land in that location. Climatic conditions, evidence of tectonically driven subsidence, hydrothermal activity, and rhyolitic ash fall make it a prospective site for lithium brine. An Environmental Assessment was performed by the BLM in 2019 and they issued a FONSI. Lithium is primarily used for batteries, as well as electric vehicles, aircraft, and high speed drains.