Chalcopyrite Electrowinning Process
About 85 percent of the copper produced in the United States is derived from copper sulfide ores by flotation, smelting, and electrolytic refining. Chalcopyrite is the predominant copper sulfide mineral in vein and disseminated porphyry-type deposits. Projected production of chalcopyrite concentrates from copper deposits now being developed and from expanded operations will soon exceed existing […]
How to Convert Stainless Steel Dust – Waste to Alloy
The manufacture of stainless steel results in a variety of wastes; the number, quantity, and composition are dependent on the manufacturing method used, the alloys produced, and the manner and degree of finishing of the metal products. A single domestic plant using conventional electric arc furnaces in conjunction with the argon-oxygen process, and producing finished […]
Heat Capacity Enthalpies of Cuprous and Cupric Sulfides
The present investigation of the low-temperature heat capacities and high-temperature enthalpies of synthetic cuprous sulfide and cupric sulfide is one in a series of thermodynamic studies by the Bureau of Mines on metallurgically important copper compounds. Despite the importance of cuprous and cupric sulfides in the processing of copper, thermodynamic data for these substances are […]
Use Sulfuric Acid to Recover Zinc
This investigation was conducted by the Bureau of Mines in support of its overall goals of helping to maintain an adequate supply of minerals and metals for future national needs with minimum waste and environmental degradation. The objective of the investigation was to develop a hydrometallurgical method of producing zinc from ZnS (sphalerite) concentrates without […]
How Water Sprays Affects – Impacts – Helps Dust Suppression
The Federal Coal Mine Health and Safety Act of 1969 specified that the average respirable dust level to which a miner is exposed during the work shift must be 2.0 mg/m³ or less as of January 1, 1973. In response, the Bureau of Mines initiated a program to develop new and improved methods of technology […]
How to Design Uranium Ion Exchange
The Bureau of Mines has developed and tested countercurrent fluidized bed, multiple-compartment ion-exchange columns (MCIX) to recover uranium from mine water, clear solutions, and slime slurries. A 14-inch-diameter MCIX absorption column and a 4-inch-diameter fixed-bed upflow elution column were field tested on uranium-bearing mine water at Bingham Canyon, Utah, and Grants, N. Mex. The same […]
Rock Sample Nondestructive Evaluation
As part of a program on mine safety directed by the U.S. Bureau of Mines, the Oak Ridge National Laboratory (ORNL) studied radiographic techniques on specimens of stressed rock. This phase of the program on mine safety is related to the structural integrity of the roof of the mine. A common practice for roof support […]
Smelting Nickel Electric Furnace
This Bureau of Mines report results from a study on prereduced nickel concentrate from the FENI project in Yugoslavia; this study was conducted in cooperation with McKee Overseas Corp., Western Knapp Division. The Bureau was particularly interested in establishing the chemical relationships between pre-reduction of low-grade nickel ore and the ferronickel produced by smelting the […]
Mine Stoppings
Most of the mines with large openings in the United States today are salt and limestone mines. Some potash and trona mines also have moderately large openings. Moreover, it is expected that in the near future numerous underground oil shale mines will be developed in the oil shale regions of Colorado, Utah, and Wyoming. These […]
Iron Oxide Pigments
Until the late 19th century iron oxide pigments were obtained wholly from natural materials, generally with little alteration other than physical purification. In some cases roasting or calcination was also carried out. However, beginning in the first part of the 20th century, chemical methods were developed for synthetic production of commercial iron oxides. Synthetic production […]