Flocculant Dilution System in Thickener Feed well
In order to maximise the benefits obtained from flocculating agents when used as settling aids in high rate and conventional thickeners, it is often necessary to dilute the thickener feed prior to flocculant addition. In some cases, no flocculation at all is possible unless dilution water is used. The most common method of diluting thickener […]
Fine Coal Filter Cake is Affected by Copper Ions
The yield of most types of dewatering installation has been shown to be related to cake specific resistance. Any sludge conditioner which significantly reduces the specific resistance will have a marked effect on the yield, and hence the size of the dewatering equipment required. Results from the current research show that the specific resistance behavior […]
Upgrading Tantalum Concentrates
The McAllister Ta-Sn deposit, located in Coosa County, Alabama, consists of a series of complex pegmatite dikes and pipes which intrude a granite pluton formation. Wodginite ((Ta, Nb, Sn, Mn, Fe)16O32) is the primary tantalum mineral. The deposit was discovered in 1982 by Callahan Mining Corporation, of Phoenix, Arizona, through stream-sediment reconnaissance and soil geochemical […]
Mining Equipment: Select, Buy & Maintain
Mining Equipment Selection Some basic parameters had to be defined at the time: Mechanical or diesel electric trucks. Number of shovels versus size versus number of pits in operation. Size (height and width) of shops and doors. Number of repair bays. Cranes capacity. Number of service equipments (graders, dozers, loaders). The maintenance shop was designed […]
Wet Screening
Immediately after operations commenced in 1972, Freeport experienced a crusher availability that was less than 50%. It was obvious that a change needed to be made. Primary wet screening was selected to remove the fines which caused plugging of the secondary and tertiary crushers and blinding of the tertiary screens in 1972. Today Freeport’s concentrator is […]
Zinc Column Design
Figure 1 shows the flowsheet for the conventional flotation circuit at Ozark-Mahoning. The plant processes 24.5 mt of ore/hr (27 st/hr) with an average particle size of 60 percent less than 45 µm (325 mesh). Pilot Testing Apparatus and Procedure The controller input was a signal from a level sensor that measures the slurry/froth interface. […]
Paste Backfill Fundamentals
Paste is a high density mixture of water and fine solid particles with a relatively low water content (10-25%) such that the mixture has a consistency as measured by the ASTM slump cone test from slightly greater than zero up to nearly 12 inches (305mm). Particles of different size classes will not segregate or settle […]
Selective Flocculation of Zinc Concentrate to Reduce Silica Contamination
Selective flocculation was used to produce superclean zinc concentrate with minimized silica contamination. Research was carried out on a flotation concentrate from the Jersey Miniere Zinc Company (JMZ) in Gordonsville, Tennessee. The material was first dispersed with sodium silicate and then causticized tapioca starch was used to selectively flocculate the sphalerite, leaving the silica in […]
Dragline Mining & Reclamation Mining
The unique application of a large walking dragline in the mountains of southern West Virginia was developed and implemented by Hobet Mining, Inc. Hobet is an independent operating subsidiary of Ashland Coal and is headquartered at the No. 21 Mine in Boone County, West Virginia, near Danville. Hobet also operates the 07 Mine located in […]
Puerto Rico Mining & Precious Metal Mineralization
Mining has never been a major source of income for Puerto Rico. The Spaniards mined gold placer deposits during 1509-1579, and extracted an estimated 1,200,000 troy ounces of gold. However, economics at the time discouraged further mining, and richer sources of gold and silver had been found elsewhere in the New World. The labor source, […]