How Freezing Affects Rock Breakage

Critical size material is defined as ore that is too small to be effective grinding media and too large to be ground. This data showed that both specific energy consumption and critical size production increased during the winter months. The increased energy consumption was in part a result of an increase in the viscosity of … Read more

Electrowinning of Gold & Silver from Copper Bearing Cyanide Solutions

One stage of the cyanide leach process to extract submicron Au particles from disseminated Au ores frequently uses electrolysis. Metals are electrowon from a solution containing Ag, Au, and Cu as cyanide complexes. The electrolyte commonly has Ag and Au concentrations in the 10 to 50 µg/mL range, while Cu, depending on the ore, may … Read more

How to Recover Hematite & Chromite Fines by Wet Magnetic Methods

Wet magnetic separation methods for recovering hematite and chromite fines and ultrafines are investigated in this paper. These methods include wet high intensity and high gradient magnetic separations, carrier or “piggy-back” magnetic method, magnetic field-induced aggregation and magnetic seeding. This investigation indicates that wet magnetic separation is more efficient for fines and ultrafines whereas other … Read more

Bioleaching Cadmium Sulfide

The applicability of electrochemical techniques in the elucidation of intermediate reactions in the bacterial oxidation of cadmium sulfide minerals has been demonstrated. Furthermore, it was found that the bio-oxidation process was solid-state diffusion controlled. Greenockite (CdS) and hawleyite (CdS) are the most important cadmium minerals, which occur as minor constituents in ores of zinc, lead … Read more

Acid Leaching Copper Flotation Concentrate

As an alternative to Acid Leaching, Copper Chalcopyrite (CuFeS2) concentrates are processed traditionally by smelting, which results in sulfur dioxide (SO2) emissions. The development of a hydrometallurgical process for recovery of metals from concentrates of Cu ores offers industry a low-cost, low-pollution alternative to the traditional pyrometallurgical practices. The hydrometallurgical leaching of chalcopyrite with acid … Read more

Large Melting Furnace – City Waste

The most widely applied method for the disposal of waste materials, including sludges, dusts, scales, leachable slags from smelting or melting operations, and residues from the combustion of organic materials including municipal wastes, is to inter the materials in an appropriate landfill. Small quantities of some wastes are encapsulated within Portland cement or sulfur, and … Read more

Recover Neodymium from Permanent Scrap Magnet

Develop hydrometallurgical or pyrometallurgical recycling methods to recover valuable rare-earth compounds from various forms of NdFeB magnet scrap. The U.S. Bureau of Mines (USBM) has developed technology to treat and recycle a variety of wastes containing valuable and strategic metals. As part of this effort, the USBM developed a process to separate neodymium and other … Read more

How to Make Graphite Flakes from Steel Waste

Develop a technology for producing high-quality flake graphite from the steelmaking waste known as kish. Approach: Treat the waste kish as an ore and apply mineral processing techniques of physical beneficiation and chemical purification to produce a range of graphite products competitive with the natural mineral. Graphite is a naturally occurring form of carbon with a … Read more