CALIFORNIA BORAX MINE DOMINATES WORLD SUPPLY
Industrial mineral by Harold Hough
Mention borax and most people think about mule teams and laundry detergent. Many of a certain age will also think about the TV show Death Valley Days and its host Ronald Reagan. However, few people know that these borate minerals extensively mined in the anti-mining state of California.
Borax (formerly US Borax) is a part of the Rio Tinto Group and operates California's largest open pit mine in Boron, California - one of the richest borate deposits on the planet. The company supplies nearly half the world's demand for refined borates.
Borax began doing business about 130 years ago in Death Valley, California and today mines at its open pit operation in Boron, CA. This mine, which supplies nearly half of the world’s borax was discovered in 1925 and went into production in 1927. Originally, it was an underground mine for mining tincal ore; the principle sodium borate mineral. In the late 1950s it became an open pit operation for mining both tincal and kernite, which is used for manufacturing borates and boric acid.
At the same time the mine became an open pit operation, processing facilities were built on site. This allowed it to become one of the major suppliers of borates and boric acid. Most of the processing of the borates for agriculture, industrial, and specialty applications occurs at Boron and at a second refining and distribution operation in Wilmington, CA.
Borax is commonly though of as a laundry detergent, and for good reason. Borates have unique properties that help stain removal and bleaching, while softening water and boosting surfactant performance. Borates also control bacteria and fungi.
Although the Boraxo/Borateem/20-Mule Team product lines were sold to Dial Corporation in 1988, there are still many products that Borax produces. It’s a critical component in fertilizer because boron is an essential micronutrient for plants, vital to their growth and development. Without sufficient boron, plant fertilization, seeding and fruiting are not possible.
One of its oldest uses is in ceramics, as evidenced by Chinese ceramics from the tenth century AD. Borates are used to initiate glass formation and reduce glass viscosity, helping to form a smooth surface; and to reduce thermal expansion, facilitating a good fit between the glaze or enamel and the item it covers. Borates in glazes and enamels also increase the refractive index, or luster; enhance durability and resistance to chemicals; and help dissolve coloring agents.
It’s ironic that most of the world’s borate mining takes place in California, one of the world’s most environmentally strict regions. However, Borax has managed to continue to mine borates while establishing a great environmental record. In 2004, it won Governor Arnold Schwarzenegger's Environmental and Economic Leadership Award. "Each one of these recipients has shown a deep commitment to balancing environmental preservation and protection with the need to keep California's economy growing. I commend them for their efforts," said Governor Schwarzenegger.
Since the mine is in the Mojave Desert, one of the challenges is water conservation. Water is necessary for refining the borates, in addition to dust control. However, the biggest problem isn’t getting it, but properly disposing of it after it has been used. Borax has been committed to recycling and reusing much of the water that it uses in the refining process. The rest of the effluent from the refining process - mostly water and dissolved borates - is discharged into lined ponds. After the water evaporates, the borates are sent back to the refinery.
The process is also allowing the mine to reclaim some borates lost in older evaporation ponds. Borax is using magnetic separation to extract residual borates from the clay in older ponds for refining before sending the wastes to on-site landfills.
Since the mine is located in the open desert, it also has many native species, some of which are endangered, such as the desert tortoise. Unlike other endangered species, the desert tortoise poses special considerations. Since it lives in arid areas, it must conserve water to survive. If it feels threatened, the tortoise excretes its foul smelling body fluids to discourage its attackers. This can be fatal to the tortoise if it can’t replace the lost water quickly. Therefore, someone who wants to move the tortoise out of the way can easily trigger this defense mechanism and unwittingly cause its death. Consequently, someone trained in moving tortoises has to be called in every time.
Like the tortoise, Borax has shown the ability to operate in difficult environments. Borax has managed to survive the same in the same desert despite some of the world’s most stringent environmental regulations. It has taken a lot of work, but it has proved that while mining is an endangered industry in California, it isn’t extinct.