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Technology Centrifugal Concentrators The operational principle of the concentrators is separation of the feed material in the centrifugal field into the two fractions, namely a “light” and “ heavy” fraction. Separation occurs as a result of interaction of the stream of fluidization water, centrifugal forces and gravity field which effect a particle in a horizontally or inclined rotating rotor. The intensity of the process increases due to vibration of mineral bed which is determined by such horizontal or inclined position of the rotor. Feed material is reported into a high frequency rotating rotor where it is accelerated to the angle speed close to the speed of the rotor. At the same time fluidization water is added under pressure into the rotor. As a result particles with SG higher than a specific figure (“heavy” fraction) move towards the walls under the impact of centrifugal forces, face the stream of incoming water and settle along the walls in the riffles. Particles of the material with lesser SG (‘’light” fraction) are squeezed out toward the inner surface of the bowl and are discharged with water. The level of separation, particularly of fine gold, increases due to horizontal or inclined position of the rotation axis. The particles, stuck in the riffles, vibrate due to gravity vector, which varies cyclically during rotor rotation. Gradually substitution of lighter particles with heavier ones forms a heavy fraction. The process efficiency depends on the water pressure sizing range and solids and liquid ratio in the feed material. Horizontal or inclined position of the rotation axis adds up to the unit operation reliability, protects bearing unit from water. This method and the concentrators using it are patented. Gold Extraction EffeciencyFollows a graph indicating the level of free gold extraction from milled ores, gold bearing sands, tailings and dumps, using Itomak concentrators. Free gold extraction from the ores is also conducted successfully with Itomaks which is indicated in the graph below. The level of extraction depends to a great extent on the prior ore treatment, like milling and grinding as well as sizing. All Itomak concentrators had undergone thorough tests by relevant Russian bodies and are fully certified, complying with sanitary-hygienic norms of the Russian Federation. Certificate :ROSS RU.IT130,C00878 012696 dtd. 28.05.2001, TU 3617-001-50766523-00. Every delivered unit is supplied with passport, operating instructions and a spear part kit. Warranty period for the units is 12 months since the day of delivery. A specialized catalogue is submitted on request with detailed technical specification of all the units as well as with a list of services provided by this company Basic Specification of Itomak Concnetrators with Automated Concentrate Discharge
Note: concentrators with capacities of 0,1 and 1 t/h of solids may be delivered with a system of manual concentrate discharge. Photo: Itomak concentrator at Megamore plant, Welkom, RSA Magnetic and Magnetic Liquid SeparatorsThe process of gold extraction from concentrates is associated with labour intensive, expensive methods, often involving poisonous chemicals like cyanides. It produces a negative impact on the economics of mining and deteriorates ecological situation in the vicinity. This company offers a principally new technology of magnetic liquid separation which results in extracting gold in a form of alloying composition. More and more Russian gold companies resort to this prospective method. Similar to gravity beneficiaiton this process is sometimes called separation in pseudo heavy media. The effect of pseudo loading of ferro magnetic liquids is determined by impact of non-uniform magnetic field. As a result in such liquids, beside Archimedus force, an additional regulated displacing force of magnetic origin emerges. This force depends on the field intensity and ferromagnetic liquid concentration. By changing the above parameters it is possible to reach the displacement force enough for floating minerals of any SG. By regulating ferromagnetic liquid concentration and magnetic field gradient it is possible to regulate the movement of particles with various SG and thus separate them efficiently. In most cases we use permanent magnets. It makes a separator compact, light and low on power consumption. The company is engaged in modifying the process by creating a centrifugal magnetic liquid separator. The acceleration in centrifugal fields may exceed gravity by dozens of times. The speed of particles transformation increases proportionally, speeding up separation intensity. Fine particles are moving much quicker than under normal circumstances and the unit picks up very fine particles of metal. We suggest our SMS-20 dry magnetic separator for the purpose of concentrate preparation for further treatment in a liquid magnetic separator. It is meant for removing from the concentrate of magnetic and low magnetic fractions which should not get into magnetic liquid separators. Usually it is a two stage process. At the first stage metal scrap, magnetite and other magnetic impurities are removed with permanent magnets. At the second stage electric magnets remove low magnetic fraction. The two stages take place simultaneously and both systems are fixed on one frame. This dry magnetic process may be used without resorting to magnetic liquid separation. Basic Specification of Magnetic and Magnetic Liquid Separators
Photo: promotional leaflet Additional and Auxiliary ProductsThis company supplies the following additional equipment: - self cleaning vortex filters which are installed between a pump and an Itomak concentrator if circulating water is used in the process; - sets of geological sieves with mesh size from 40 microns to . Diameter is 200mm. - Induction furnaces for gold refining with crucible volumes from 0,06 to and temperatures of up to 1500 deg. C. Photo: SMJ-EM-20 Magnetic Separator installed at Bereleh gold extraction plant, Magadan Region References Since 1996 more than 350 Itomak concentrators of various capacities operate with high effeciency, extracting placer and ore gold and platinum by various companies in Western Siberia, the Urals, Saha (Yakutia), Buriatia, Hakasia, Altai Mountains, Krasnoyarsk, Habarovsk, Magadan and Amur regions of the Russian Federation. A number of units are commissioned abroad, including , , , , Kazahstan , Kirgiziia and South Africa.
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