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. … Read more

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 … Read more

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 … Read more

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 … Read more

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, … Read more

Sample Preparation Method for Cyanide Shake Assay of Gold

A series of tests were undertaken for the Aurora Partnership-Aurora Project to solve inter-laboratory variations in the analyses of blast hole cuttings. Initial concern was centered on the probability that free gold occurrence was resulting in erratic results for the mine’s cyanide shake assays and outside laboratory fire assays. Test Procedure A 50 kilogram bulk … Read more

Leaching & Recovery of Phosphoric Acid Gallium & Silver

Treater Dust is the name given to the material that is collected in electrostatic precipitators used for off-gas cleaning of elemental phosphorus furnaces. Elemental phosphorus is made by reacting phosphate ore, silica, and coke in an electric furnace, as shown by these reactions: 2Ca3(PO4)2 + 6SiO2 → P4O10 + 6CaSi03 P4O10 + 10C → P4 + 10CO … Read more

Drag & Hoist Ropes of Dragline Performance

Typical dragline rigging includes several sets of ropes: hoist ropes, drag ropes, dump ropes and boom suspension ropes. The drag and hoist ropes contribute most to the dragline operating cost, and significantly influence dragline productive time. Both work in very difficult conditions and wear out rapidly. As a result frequent rope changes are required at … Read more

What are the Effect of Sample Storage on Kinetics of Pyrite Oxidation

Pyrite oxidation has been studied extensively in relation to its role in sulfide mineral flotation. Although pyrite usually lacks economic value in polymetallic ores, it generally acts as an undesirable constituent which complicates the separation of valuable minerals. This mineral is also considered to be the main source of acid mine drainage. The formation of … Read more

Synthetic Serpentinite

Serpentinite minerals are available in large quantities from asbestos mining activity. The granular or fibrous serpentite, at temperatures greater than 700°C, will recrystalize into olivine, forsterite and enstatite. These minerals have been used and studied for decades and are environmentally safe. The thermal process changes the composition and properties of the original mineral. Therefore, the … Read more