We used the original flowsheet for two and a half years and made concentrates containing 16%-18% insol. Then we were asked to reduce the insol content as much as possible without additional capital expenditures in an effort to improve the smelting process. One of the 7 x 10 bail mills had been outfitted with four … Read more
Arsenic is produced in the United States as a byproduct from base metal ores. Although this production supplies only about one-half of the national demand, arsenic is generally not recovered but is treated as a troublesome impurity. Its complete recovery in domestic metallurgical plants could nearly supply the country’s arsenic needs, but complicated and inefficient … Read more
One goal of the U.S. Bureau of Mines metallurgy research program is to reduce the objectionable impact of mineral-processing operations upon the environment to the lowest possible level consistent with a viable minerals economy. The citrate process for flue gas desulfurization of (FGD) is a product of continuing Bureau research in pursuit of this goal, … Read more
The Stillwater Complex in Montana (mainly the Benbow and Mouat deposits) contains an estimated 15.7 million short tons of ore containing 1.3 million short tons of recoverable chromium. This represents approximately 75 percent of available domestic chromite and could supply U.S. needs for about 4 to 5 years, but it is low in grade and … Read more