Air-Sparged Hydrocyclone for Fine Gold Flotation
Pilot-scale tests indicate that effective concentration of fine gold from Colorado River sands can be achieved by flotation with the air-sparged hydrocyclone. The fine sands (55% minus 400 mesh and 0.01 opt) from gravity concentration were processed with a 5-cm air-sparged hydrocyclone (capacity -1.0 tph dry solids). Concentrate grades as high as 5.0 opt were […]
How to Extract Precious Metals from Geological Brines
It is now well documented that trace amounts of silver, gold, and platinum group metals occur in certain geothermal brine deposits. A significant body of literature has been generated over the last twenty years which describes attempts to quantify the frequency and levels of these precious metals in the brines. There are numerous reports of […]
Effect of Mill Load Level and Speed on SAG Mill Operation
The SAG milling of ores with markedly variable grinding rates presents definite process control challenges. Decisions must be made regarding the selection of the most appropriate combination of mill volumetric load level, percent solids, and mill speed for the combination of ore types being processed at the moment. Circuit Description Chino’s concentrator is described in […]
Dewatering Aid
The moisture content of coal has become more important in the product analysis. The high content surface area and corresponding high moisture of fine coal can contribute to most of the overall product moisture. As the preparation engineer exhausts his talents and capital budget to bring product moisture into compliance, alternate methods of fine coal […]
Merrill-Crowe Plant Design Factors
The removal of metal values from cyanide solutions, fortunately, can be done in several ways. The oldest practiced method is, cementation with zinc, or Merrill-Crowe. The original patent for recovery of gold and silver from cyanide solutions described precipitation with zinc dust. Most early practitioners, however, used granules of zinc in a successful attempt to […]
Hydrodynamic Bearings for Large Diameter Machines
The hydrodynamic bearing has the following characteristics: Lubricant film thickness and pressure are maintained by lubricant which is drawn into a wedge shaped zone between the journal and the bearing, due to their relative velocity and the viscosity of the lubricant. Lubricant flow conditions are laminar. Lubricant film thickness is sufficient to prevent metal to […]
Deister Flotaire Column Flotation Cell
The FLOTAIRE Flotation Cell is a column flotation cell designed to utilize aspirated gas in surface tension lowered water to generate extremely fine bubbles. The non-mechanical distribution of the fine bubbles throughout the column without agitation or turbulence allows for greater bubble/particle adhesion. The combined effect of these operating conditions shows enhanced flotation recovery of […]
Copper Electrowinning
The very survival of the U.S. copper industry is presently tied to the leach SX-EW process, a technology which 15-20 years ago was considered too radical and far fetched to be accepted by the industry. It came to life rather dramatically with the Ranchers Bluebird Mine and shortly thereafter with the Cyprus Bagdad plant. All […]
Classification & Concentration of Heavy Minerals
The recovery of heavy minerals by gravity concentration during grinding is practiced widely in the minerals industry. Studies have shown that the grade and recovery of the concentrate depends not only on the performance of the concentrator but also on the degree of liberation achieved in the mills and the scavenging action of the hydrocyclones […]
Charge Motion inside a SAG Mill
For proper design of SAG mills and other types of grinding mills, the operating conditions have to be defined. Predicting the composition of the SAG mill charge is a difficult task since a number of significant phenomena associated with the charge motion must be taken into consideration. These observations and assumptions led to the recognition […]