Vibrating Screen

For efficient wet or dry screening—Hi-capacity, 2-bearing design. Flywheel weights counterbalance eccentric shaft giving a “true-circle” motion to screen. Spring suspensions carry the weight. Bearings support only weight of shaft. Screen is free to “float” and follow positive screening motion without power-consuming friction losses. Saves up to 50% HP over 4- bearing types. Sizes 1 x … Read more

Jaw Crusher Working Principle

A sectional view of the single-toggle type of jaw crusher is shown below. In one respect, the working principle and application of this machine are similar: the movable jaw has its maximum movement at the top of the crushing chamber, and minimum movement at the discharge point. The motion is, however, a more complex one than the … Read more

Wilfley Table

wilfley table

The Wilfley table is a truly remarkable gold concentrating table first built on a preliminary scale in May, 1895. The first full-sized table was built by Mr. A. R. Wilfley, and was used in his own mill in Kokomo Colo., in May, 1896. The first table sold for installation was placed in the Puzzle mill, Breckenridge, … Read more

Fluorspar Beneficiation Process Plant

The Fluorspar Beneficiation Problem Acid grade fluorspar which is in great demand by the chemical and aluminum industries, must contain at least 97.5% CaF2 with not more than 1.5% SiO2 and 0.5% Fe2O3. Often the Silica is limited to 1.2% with penalties starting at 1.0% SiO2. These limitations on grade and impurities require extremely close … Read more

Metallurgical Plant Sampling Techniques

Concentrator Slurry Sampling In milling operations sampling is essential to proper control. This can only be based on the results obtained through sampling the various materials throughout a plant. Sampling of the feed, concentrates, tailings and other products give data indicating the effectiveness of the entire operation. Often these results are desired for comparative purposes for each … Read more

Bowl Concentrators

Bowl concentrators have been used only to a limited extent in small placer operations. The two most popular designs were the Ainlay and Knudsen bowls. There is little difference in design and operation between the two, except for riffle design and minor variations in bowl size and shape. They were used primarily as cleaners, but … Read more

Bioleaching Test Procedure

Pulps of 20% solids is prepared from -200 mesh pyrite concentrate (after froth flotation), and is inoculated with 5% (V/V) of adapted bacterial solution. The bioleaching tests is carried out in 250 ml Erlenmayer flasks, each contained about 220 ml pulp. The pulps is aerated with air bubbling at one liter per minute air flow … Read more

Heap Leaching in Cold Weather & Winter

Extended freezing conditions exist in many parts of the world in the winter because of latitude or high altitude or both. Such conditions, coupled with the sprinkling techniques commonly used in heap leaching, result in formation of layers of ice which inhibit leaching by tying up solution inventory on heap surfaces and shutting off solution … Read more

Heap Leach Feed Preparation

Some gold and silver ores are difficult to successfully heap leach because of the high percentage of clay, and/or fines which are intrinsic in the material or generated by the crushing or ore preparation. This type of ore can result in extremely slow percolation during heap leaching. Channeling can result which promotes dry areas within … Read more

Heap Leaching at Altitude

It is feasible to conduct cyanide heap leaching at high altitudes as has been demonstrated by a number of pilot and commercial operations in the altiplano of the Andes Mountains. Operations at elevations in excess of 3000 meters (9800 ft) must be conducted with care to insure that heaps are fully permeable and the lixiviant … Read more