Magma Copper Co. (Tucson)

The Magma Copper Company, originally founded in 1910, was one of the biggest producers in the copper industry. In 1995 the company was bought by the biggest industrial and resource company in Australia: Broken Hill. The subsidiary was then merged with a copper business owned by Broken Hill, forming the BHP Copper Group. Before being bought out, the Magma Copper Company was based out of Tucson, Arizona. It had just under five thousand workers.

The founder of the Magma Copper Company was Colonel William Boyce Thompson, who started off as a mining engineer who eventually became a trader on Wall Street. The company grew steadily, operating in an area which had been called the Pioneer Mining District. It contained a mine known as the Silver Queen Mine, which had yielded ore since 1877. The Magma Copper Company controlled the mine after beginning operations and used it the entire time the company existed.

By 1950, it had become the eighth most prosperous copper production company in America.  During the 1960s, the company continued to grow both economically and productively. It expanded its production of copper by buying and using new property. In 1968, the company was earning $11 million a year. On March 1970, they then started building a copper refinery that would refine 200,000 tons annually.

Since knowledge of the danger of the substance was not publically available, asbestos was quite commonly used in factories, power plants, and many other work areas throughout the 20th century. The Magma Copper Company, like many similar companies, used asbestos because it was a good insulator of heat and electricity.  It was highly useful in insulating materials for the smelting and processing equipment as well as protective clothing for metal workers. Unfortunately, consequences of using the fibrous mineral were not foreseen, and the effects went undetected for many decades. Many decades after the use of asbestos became widespread, workers began suffering from serious diseases as a result of exposure.