Numerous competitive tests all over the world have conclusively proved the real worth of these cells to many mining operators who demand maximum result at the lower cost. The location of the feed pipe and the stationary hood over the rotating impeller account for the simplicity of the Denver Sub A cell construction.
GOLD FLOTATION. The flotation process, which is today so extensively used for the concentration of base metal sulphide ores and is finding increased use in many other fields. In 1932 flotation plants began to be installed for the treatment of gold and silver ores as a substitute for or in conjunction with cyanidation.
Sub A Flotation Cells have been developed over the intervening years since 1927 until today there are over 26,000 cells in operation. Flotation cells are standard equipment for an ever widening range of metallurgical and industrial problems. They are being used in plants of all types and sizes and they are giving excellent results at minimum cost at tonnages of a few tons up to 35,000 tons per 24 hours. To take care of the wide range of problems confronting the flotation process, the Sub As are built in a wide and flexible range of commercial sizes, from the No. 8 through the No. 12, No. 15, No. 18, No. 18 Special, No. 21, No. 21 Deep, No. 24 and the No. 30. There is a particular size cell for every problem and tonnage, with each cell having incorporated into its design features to take care of any condition. This is the basis on which Sub A Cells have been designed. Standard cells are as follows: The construction of the Sub A Standard Flotation Cellis with double welded ste...
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The widespread success of the Sub A Flotation Cell is attributed to the basic qualities of the design of this type Flotation Cell. Successful metallurgy results from the distinctive gravity flow feature, which assures positive circulation of all pulp fractions with reagents from cell to cell and hence results in high efficiency.
The passage of pulp through the cell and the action created in the impeller zone draws air down the stationary standpipe and from the partition along the feed pipe. This positive suction of air gives the ideal condition for average flotation and the action in the impeller zone thoroughly mixes the air with the pulp and reagents. As this action proceeds, a thoroughly aerated live pulp is produced and furthermore, as this mixture is ground together by the impeller action, the pulp is intimately diffused with exceedingly small air bubbles which support the largest number of mineral particles. For particular problems the aeration in the Sub A can be augmented by the application of Supercharging, whereby fully controlled air under low pressure is diffused into the pulp. This feature is accomplished by the introduction of air from a blower or turbo compressor through the standpipe connection into the aerating zone where it is premixed with the pulp by the impeller action. This supe...
The capacity of a flotation cell, treating any ore, depends upon facts and conditions which can best be determined by experience and test work. The pulp density and flotation contact period required materially affect the capacity of a Flotation Cell. With these factors known from previous work or test results, the size machine can be determined. Three conditions are factors in determining the proper size cell and number of cells.
PROBLEM 1How many No. 15 Sub A Cells are required to treat 50 tons of gold or lead ore per day, with treatment time 12 minutes, dilution 3 to 1, and sp. gr. 3.0? Tons x Treatment time /Tabulated tonnage figure = 50 x 12/162 = 3.7 cells ANSWERThe result is 3.7 cells, thus use 4 No. 15 Sub A Cells. PROBLEM 2How many No. 18 Sp. Sub A Cells are required to treat 125 tons of lead zinc ore per day, with treatment time 14 minutes for the lead, dilution 3 to 1, and with treatment time 16 minutes for the zinc, dilution 3½ to 1, and sp. gr. 3.4? ANSWER 125 X 14/327 = 5.4, thus use 6 No. 18 Sp. Cells. ANSWER 125 X16/281 = 7.2, thus use 8 No. 18 Sp. Cells.
Continuous 24 hour per day service depends upon the mechanical design and construction of a Flotation Cell. There is no unit so rugged, nor so well built to meet the demands of the process, as the Flotation Cell. The ruggedness of each cell is necessary to give long life and to meet the requirements of the process. Numerous competitive tests all over the world have conclusively proved the real worth of these cells to many mining operators who demand Maximum results at the lowest cost. The location of the feed pipe and the stationary hood over the rotating impeller account for the simplicity of the Sub A cell construction. These parts eliminate swirling around the shaft and top of the impeller, reduce power load, and improve metallurgical results. Improvements in construction of Sub A cells during the last ten years have been gradually made as a result of plant scale testing and through suggestions from the mining fraternity. Today the Sub A is mechanically unexcelled with...
Cell liners fit easily into the cell and consist of four cast iron liners and a rubber bottom liner. This bottom liner consists of a rubber compound similar to that used on the molded rubber parts, firmly bonded to a steel backing so that it does not rip or blister. This liner is held in place at the edges by the side liners. Cell drainage is through an easily accessible port at the back of each cell. A small recirculation gate is provided near the top of each cell so that if desired, a portion of the pulp can be removed from the middling zone and returned to the impeller for retreatment. This recirculation feature influences the production of high grade concentrates in some cases. A gate is provided for this recirculation opening so that an adjustment of the zone and amount of recirculation can be varied. Flotation Cells are provided with openings in the partition plates for by passing the pulp from cell to cell without the pulp circulating through each hood feed pipe. In normal op...
Each Sub A Cell is provided with an air bonnet on the shaft assembly so that low pressure air may be connected if desired. To assure complete diffusion of air in the pulp an automatic seal is built in each casting. When desired, a discharge may be taken at partitions on Sub A Flotation Cells by reversing the casting and providing a special plate. Feed may enter any cell of a Flotation Cell, through the front or back. The hand of the Sub A may be easily changed in the field by reversing the position of the casting with plate and partition plate. The hood assembly is turned through 180 degrees and the feed liner is changed with the liner in the opposite segment. Source:This article is a reproduction of an excerpt of In the Public Domain documents held in 911Metallurgy Corps private library.
Flotation technology is an integral part of the mining and mineral processing industry, with numerous systems installed all over the world. This technology is commonly used in base metal processing , mineral processing , and within the energy sector .
Along with mechanized mining equipment, froth flotation dramatically improved the efficiency of gold mines. Thanks to this process, miners and refiners are able to extract quality minerals from ore at lower grades than has been previously possible making it perhaps the most important mining industry innovation of the 20th century.