Initial metallurgical tests on its wholly owned North Star deposit at the Gunnison copper project in southern Arizona show that acid consumption and copper recovery will support in-situ mining, Excelsior Mining Corp. said this morning. “We are very pleased that the results from the recent test work confirm our view that the recovery rate...
The Copperstone gold mine in western Arizona has entered the final phase of construction, with dry commissioning of the processing plant under way, American Bonanza Gold Corp. reported this morning. All processing plant and crusher equipment has been installed and wired. Construction of the crusher back wall and dump pocket is complete. Emplacement of...
Its Copperstone gold mine in western Arizona is in the final phase of construction prior to the commissioning of the gold-processing plant, which is scheduled to commence before the end of October, American Bonanza Gold Corp. reported yesterday. All major surface administrative construction projects are complete, including new offices, upgraded or new maintenance and...
Engineering and design work at its Oracle Ridge copper mine north of Tucson is on schedule and about 40% complete, Oracle Mining Corp. reported Wednesday. The plant design and economic study is based on a 2,000-tpd processing facility and related facilities including the tailings impoundment. The tailings impoundment area design is 60% complete and will...
Silver production in extreme southern Arizona is inextricably tied to the earliest history of the state and its name, but never has it been conceived on such a large scale as is currently planned. While the planchas de plata were unbelievably valuable — even if only half of the legendary history is true — today’s Hermosa...
It seems just yesterday that Asarco was teaming up with the U.S. Bureau of Mines (now defunct) to experiment with in-situ leaching of copper at the Santa Cruz project near Casa Grande in central Arizona. This was before even heap leaching, and solution extraction-electrowinning, had become mainstream. While that test didn’t give good results...
