Modern Mining & Processing

Modernization programs begun in the 1980s helped make the Santa Rita copper mine successful and continue today. Mining at the Santa Rita Mine occurs 24 hours a day, 365 days a year. Since 1910, more than two billion tons of material have been moved. Today, the mine is more than a mile across and more than 1,600 feet deep, and it continues to grow as copper-bearing ore is mined. Higher-grade ore is treated at a concentrator, where rock is crushed, ground, and processed from its naturally occurring 0.6% copper to about 25% copper, and copper-containing minerals are recovered by floating them. This copper concentrate is shipped by rail to a smelter in Arizona where the copper is extracted, and Chino currently produces about 100 million pounds of copper by this method each year. Lower-grade ore is treated by a solution extraction-electrowinning process in which a weak acid solution is dripped through stockpiled rock, the dissolved copper solution is collected, and the copper is concentrated from 1.3 grams per liter to 50 grams per liter. An electric current is introduced into this rich blue-colored liquid, and the copper is electrowon or electroplated onto plates called cathodes. Chino currently produces about 100 million pounds of copper by this method each year.

New Mexico · United States