On Stream Analyser Calibration OSA
The principle of the sample flows of the analyzer system is shown in Figure 4. As the analyzers are located in a separate room, many of the primary lines require pumping. The samples are returned mostly by gravity to the corresponding process pump sumps. The primary sample lines have a diverter that feeds the stream […]
Leaching Pyrite Gold Ore without Cyanide
Alternative reagents for gold leaching include thiocyanate (SCN-) and thiourea (SC(NH2)2). They are considered less toxic and more environmentally acceptable when compared to cyanide. One of the important features of thiocyanate and thiourea dissolution of gold is that the leaching can be performed in acidic media, enabling the use of soluble oxidizing agents, such as […]
Hindered Settling Column
After filling the column with water, the teeter water flow rate was set to produce the desired cut size. The feed water was adjusted to produce a feed slurry consisting of about 50 percent solids by weight The screw-feeder was then set to the desired rate. Solids were fed into the feed tube and combined […]
AG & SAG Mills Curved Pulp Lifters
Curved pulp lifters have been incorporated in SAG and AG mills in Australia. The aims have been to ensure complete discharge, at high throughput, of both slurry and coarse solids, especially at high mill rotational speeds. Curved pulp lifters can overcome incomplete discharge and back-flow of solids down the pulp lifter that can occur in […]
Shaker Table Washability Curves
Although direct comparison of table performance with jig performance gives only a general idea as to the efficiency of tables, a better understanding of the subject can be obtained from a consideration of table efficiencies in relation to the washing difficulties reflected in the washability curves of various coals. Numerous methods of interpreting washability curves […]
Gravity Concentrators & Jigs Compared
A Gravity Concentrator has the bed fluidized 100% of the time. A Jig is fluidized only 50% of the time. A Gravity Concentrator works at 150 g forces. A Jig works at 1 g. Material is caused to move in a lateral movement through the Gravity Concentrator. A Jig has a lateral movement and a […]
Double Cycloning
In conventional closed circuit grinding practice including classification in one hydrocyclone, or in a group of hydrocyclones in parallel, classification takes place in a single stage. Under conditions where the fineness of the overflow product is expressed e.g. as 95 % – x microns, the normal sharpness of size separation (recovery) at size x into […]
Carbonaceous Gold Ore Mineralogy
Mineralogy and Occurrence of Gold: The term “carbonaceous” has been loosely applied to ore constituents of widely varying characteristics. Laboratory investigations by A. S. Radtke and B, J. Scheiner (1970) of the U. S. Geological Survey and the U. S. Bureau of Mines on carbonaceous ores from Carlin showed that they contained: (1) an activated carbon […]
Titanium Castings Sand Molding Process
Objective To produce industrial-grade titanium castings by processes that are nonpolluting and lower cost than the currently used rammed-graphite process. Approach Foundry-grade zircon and olivine sands, bonded by waterglass or bentonite, are used to make shell or rammed molds which require relatively low-drying temperatures and do not generate noxious fumes during drying or casting. Procedures […]
Thiourea
Thiourea (H2NCSNH2) is an organic compound, the crystals of which dissolve in water to yield an aqueous form stable in acidic solutions. The unique feature of thiourea is that, in aqueous solution it reacts with certain transition metal ions to form stable cationic complexes. For example, the following generalized reaction illustrates the complexing role of […]