In 2011 leaching ( both heap leaching and in-situ leaching ) produced 3.4 million metric tons of copper, 22 percent of world production.
22.
In recent years, the addition of an agglomeration drum has improved on the heap leaching process by allowing for a more efficient leach.
23.
In 2015 it produced 4.6 million ounces of silver and 52, 588 ounces of gold from an open pit and heap leaching operation.
24.
That project would use a technique in which sulfuric acid is drained through piles of ore to extract the copper, a process known as heap leaching.
25.
In his role as Vice President External Affairs he briefed the Minister of BHP Billiton's intention to undertake heap leaching mineral processing trials at Olympic Dam.
26.
Cerro San Pedro ( gold and silver ) mine is located in the Mexican state of San Luis Potos?uses the process of heap leaching to recover minerals.
27.
The company was among the first in the 1970s to use heap leaching, a low-cost process in which microscopic gold is removed from huge piles of low-grade ore using cyanide.
28.
In October 2009, the company announced a Stage 4 Expansion forecasting production to increase to 10 million lb U3O8 [ 3, 846 t U ] per year using heap leaching.
29.
US gold production greatly increased during the 1980s, due to high gold prices and the use of heap leaching to recover gold from disseminated low-grade deposits in Nevada and other states.
30.
The Barneys Canyon mine in Salt Lake County, the last primary gold mine to operate in Utah, stopped mining in 2001, but is still recovering gold from its heap leaching pads.
