wet magnetic separation equipment

magnetic separation

magnetic separation

Including wet high intensity, induced roll, rare earth roll, rare earth drum, low intensity and medium intensity magnetic separators the Reading range has a magnetic solution to fit your particular processing requirements.

The WHIMS range includes 4, 16, 24 and 48 pole machines with either 68 or 120 millimetre separation matrix widths. WHIMS separators are suitable for applications requiring higher magnetic field gradients to remove weakly magnetic particles from non-magnetic concentrates. Nominal capacities range from 6 to 150 tonnes per hour.

Reading induced roll and semi-lift induced roll magnetic separators are available with 2 starts, single or twin-pass configurations in 133 millimetre roll diameter and 760 millimetre roll width or 160 millimetre roll diameter and 1000 millimetre roll width, and deliver nominal capacities of up to 12 tonnes per hour. Pilot roll laboratory scale separators are available in both induced roll and semi-lift induced roll configurations.. Typical applications include:

The rare earth magnetic separator range achieves the most effective dry separation of paramagnetic minerals at high throughput rates. The range includes Rare Earth Roll (RERS) and Rare Earth Drum (REDS) Separators which are available in a range of configurations and sizes from lab units to full production units.

wet high intensity magnetic separation

wet high intensity magnetic separation

WHIM is the short acronym for Wet High Intensity MagneticSeparation.At present, most U.S. iron raw materials are produced from magnetic taconites, which are ground to a nominal minus 270 mesh (53 micrometers), beneficiated by wet low-intensity magnetic separation, and pelletized. The taconite ore bodies generally contain 19 to 25 percent magnetic iron, defined as iron occurring in the mineral magnetite. Iron occurring in other minerals, such as iron silicates, siderite, and hematite, is generally lost in the tailings.

The iron-bearing materials intermediate in properties between the high-grade enriched iron ore deposits and the parent taconite are the oxidized taconites. The magnetite has been oxidized to hematite, and the iron silicates and siderite have been converted to goethite, a hydrated iron oxide. There may be some iron enrichment due to natural leaching of silica and migration and precipitation of iron ions in secondary iron oxide layers. Oxidized taconite is also called nonmagnetic taconite to distinguish it from the unaltered magnetic taconite. The western part of Minnesotas Mesabi Range contains in excess of 10 billion tons of oxidized taconite containing 30 to 40 percent iron. Typically, oxidized taconite surrounds and underlies an exhausted natural ore pit, while underlying the oxidized taconite is the parent taconite. In open pit mining of taconite, oxidized taconite is often removed as waste material. In some cases, oxidized taconite is being stockpiled for future use, in other cases, it is discarded with the overburden. The development of an economical method for beneficiating oxidized taconites would utilize a current waste material and convert the oxidized taconite from an iron ore resource to a reserve.

In the reduction roasting process, the hematite and goethite in the ore are converted to magnetite by heating in a reducing atmosphere at approximately 800 C. Although the first experimental plant was built on the Mesabi Range in 1934, the process has not been used commercially. The high operating cost of the energy consumed in roasting is partially compensated by reduced grinding costs and by energy returned in the conversion of magnetite to hematite during pellet induration. The capital cost, which is also high, would be reduced if roasted ore were processed in an existing magnetic separation plant. However, processing of reduction-roasted ore in a conventional taconite plant would require some modifications, because artificial magnetite has a higher remanence and coercivity than natural magnetite. After exposure to a magnetic field, very strong magnetite floccules, which entrain gangue particles, are formed. Demagnetization requires special high-frequency coils. Pilot plant results recently obtained by the Bureau of Mines show that the silica content of the artificial magnetite concentrate can be reduced to less than 5 percent while iron recovery is maintained at 80 percent by including a froth flotation step after the final magnetic separation stage.

Highly metamorphosed schistose iron ore from the Marquette range on Michigans Upper Peninsula has been successfully treated by froth flotation since 1956. The hematite in this ore occurs in the form of specularite, which is more easily beneficiated than the red or dull black hematite typical of oxidized taconites. The development of selective flocculation by the Bureau of Mines and research by the Cleveland-Cliffs Iron Co. made flotation a feasible beneficiation method for the bulk of the Lake Superior regions oxidized taconite resources. The research resulted in the opening of the Tilden plant (Marquette range, Michigan), which has a capacity of 4 million tons of pellets per year; long-term plans call for tripling the plants capacity. Mesabi Range oxidized taconites can also be beneficiated by selective flocculation-flotation; however, the much greater content of goethite in the Minnesota oxidized taconites, compared with the Tilden ore, makes it more difficult to maintain high iron recovery. A typical flowsheet for Mesabi Range oxidized taconite is shown in figure 1.

The application of WHIM separation to the beneficiation of oxidized taconites received impetus from innovative separator designs developed by G. H. Jones and J. H. Carpenter in the early 1960s. Beginning in 1964, application of WHIM separation to Mesabi and Marquette range iron ores was tested on the pilot plant scale at the Mines Experiment Station (now the Mineral Resources Research Center) of the University of Minnesota. The flowsheet developed involved WHIM separation on rodmill-ground ore to remove coarse quartz and primary slimes amounting to 20 to 30 percent of the feed weight. The preconcentrate obtained was reground in a ball mill, and the final concentrate was produced by flotation. The flowsheet development was influenced by the fact that the WHIM separators available used soft-iron spheres as a matrix and were not capable of selectively recovering the iron oxides present in particles finer than 500 mesh (25 micrometers). After flotation, overall iron recoveries ranged from 72 to 78 percent. In 1974, Kelland and Maxwell demonstrated that a continuous pilot plant WHIM separator with a matrix designed to produce high field gradients could be used to preconcentrate oxidized taconite ground to 90 percent passing 400 mesh (37 micrometers) before flotation. When a single-stage operation employing a 10-cm length of stainless steel wool matrix was used, preconcentrates containing 49 to 54 percent iron, with iron recoveries ranging from 68 to 79 percent, were obtained.

On the basis of direct operating costs, exclusive of amortization, WHIM separation, either alone or in combination with flotation, is less costly than either reduction roasting or selective flocculation-flotation. The cost advantages of WHIM separation over flotation are decreased reagent, grinding, and water treatment costs. For commercial-scale machines, the energy required to energize the electromagnets, typically in the range of 1 to 5 kwhr/ton of ore treated per pass, is small compared with the 30 kwhr/ton required for grinding. From the standpoint of capital costs, WHIM separation is significantly more expensive than flotation but probably less expensive than reduction roasting. Since WHIM separation is a relatively new and untried technology for the processing of oxidized taconites, high investment expense is a significant barrier to its application. Even at the research and development level, progress has been hindered by the high cost of effective pilot-scale machines. To minimize capital costs, the number of magnetic separation stages must be kept to a minimum.

The possibility of beneficiating the sample by WHIM separation alone was evaluated in the laboratory on 1-kg samples (fig. 2). A sample of rodmill discharge was separated in an Eriez Model L-4 WHIM separator with a 20-cm-deep matrix of 0.6-cm iron spheres and a 0.5-tesla applied field. A coarse tailing containing 31.5 percent of the feed weight, but only 3.8 percent of the iron in the feed, was obtained. To achieve sufficient liberation of the ore, the preconcentrate was reground to 80 percent passing 400 mesh (37 micrometers). Separation of the reground material was carried out with a matrix of coarse stainless steel wool and a 1.0-tesla applied field. Two stages of separation produced a finisher concentrate containing 63.5 percent Fe and 5.5 percent SiO2 with an accompanying iron recovery of 73 percent.

The laboratory results have not been duplicated in the pilot plant. The WHIM separators available for this research have not performed satisfactorily in continuous operation on rodmill discharge; the separators have either given much lower iron recovery than expected from laboratory tests or have shown a tendency to plug up during extended runs. (Design criteria for avoiding these difficulties are discussed in a subsequent section.)

The Bureau of Mines most successful application of WHIM separation on a pilot plant scale has been as a method of increasing iron recovery in the selective flocculation-flotation process. The unit operations of figure 3 were used in conjunction with the flowsheet of figure 1. The WHIM separator recovered iron values from the scavenger flotation tailings. The magnetic concentrate, after thickening, was returned to the scavenger flotation cells. During a continuous 48-hour pilot plant test in which the magnetic concentrate was recycled to the flotation circuit, the iron recovered in the cleaner flotation concentrate was increased by 2 percent with no adverse effect on concentrate grade. Average metallurgical results for a 48-hour period during which flotation was producing a low-iron tailing are shown in figure 4. Preliminary results from 6-hour pilot plant tests on higher grade flotation tailings have indicated that up to 10 percentage units of iron can be recovered by WHIM scavenging. The MEA-Sala Carousel magnetic separator used was operated at 0.6 tesla with flow through the 9-cm matrix of coarse stainless steel wool controlled by gravity.

The flotation process used was the cationic flotation of the gangue. To improve the concentrate grade, more amine collector is added to ensure flotation of coarse gangue particles. However, the added collector can also cause flotation of fine iron oxides, leading to a decrease in recovery. By providing a means of recovering the fine iron, magnetic scavenging allows positive control of the final concentrate grade while minimizing loss of iron values in the final process tailing. An effective means of controlling iron recovery while maintaining close concentrate grade control is significant in treating an ore as variable in its characteristics as oxidized taconite.

Because alternative processing methods and alternative sources of ore exist, WHIM separation will be commercially applied to oxidized taconites only if it is cost competitive. The key to minimizing costs is to optimize the separator design for a particular application. A rational optimization procedure requires a mathematical model of separator performance as a function of the basic design and operating parameters.

Most existing models of WHIM separation can be classified as highly theoretical or purely empirical. During the past few years, there has been much interest in the development of theoretical models of WHIM separation based on particle trajectory calculations. Recent computer-based models have shown some degree of correspondence with experimental results after the introduction of two adjustable parameters for each particle size. Application of a theoretical model to a practical optimization problem would require a very extensive ore characterization study followed by systematic testwork to determine the adjustable parameters. The calculations involved in finding an optimum separator design might be too cumbersome for practical design purposes, even when performed on a large electronic computer. Several empirical models relating WHIM separator performance to design and operating parameters have been published. Because the amount of testwork required expands rapidly with the inclusion of each additional independent variable, empirical models are rarely developed to the degree of generality required for optimizing separator design. Since neither purely theoretical nor purely empirical models are well suited to design optimization procedures, a significant opportunity for advancing WHIM technology lies in the development of phenomenological models, which combine the most useful features of the theoretical and empirical approaches. Typically, in this compromise approach, theoretical analysis is used to derive or suggest reasonable, uncomplicated forms of the descriptive equations, but statistical curve-fitting techniques are used to find the parameters that fit the data to the equations. With the proper form of the descriptive equations, the required number of adjustable parameters and the testwork required to establish their values can be decreased to a minimum. The following example will illustrate the development and use of a simple phenomenological model.

Concurrently with a 5-day pilot plant test during which magnetic scavenging was tested, samples of the flotation tailings were evaluated in bench-scale WHIM separation tests under controlled conditions. Over the 5-day period, a 24 factorial experiment was run. The effect of daily variations in the tailings was assessed by conducting two midpoint tests each day. The variables and levels used in the tests are shown in table 1. The dependent variable of most interest, the fractional iron recovery, was shown to be independent of the iron content of the tailings, which varied from day to day. Equations developed by Oberteuffer and Watson suggested the following phenomenological equation:

The properties of the feed, such as its particle size distribution, did not vary significantly; therefore, the model was not complicated unnecessarily by including the effect of particle size on recovery. The feed characteristics have a strong effect on the parameter and a lesser effect on the other parameters.

To obtain accurate values of the parameters, weighting factors determined by the variance of the transformed dependent variable should be used in the regression calculation. It is of interest to compare equation 1 with the strictly empirical equation of Dobby and Finch, in which recovery is expressed as a linear function of the logarithms of the independent variables. Since the left-hand side of equation 2 can be closely approximated by the linear expression 3.2 R 2 for 0.2 < R < 0.9, as long as recovery is restricted to that range, there is no practical difference between the empirical and the phenomenological equations.

A well-conceived phenomenological equation should behave properly for limiting values of the independent parameters. Although equation 1 gives correct results for limiting values of H, L, and V, it incorrectly predicts R 1 as F 0. To correct this defect, equation 1 was modified to

A plot of experimental and calculated values of R versus the appropriate function of the independent variables is shown in figure 5. As can be seen from the range of the midpoint values of recovery, equation 3 adequately represents the data within the limits of experimental error. Although the fit could be improved by a more sophisticated model, the precision of the data probably does not warrant the introduction of the additional adjustable parameters that would be required.

The utility of a simple phenomenological equation as an aid in separator design can be illustrated by an example requiring only the simplest mathematical analysis. A feature of equation 3 that makes it particularly useful for design purposes is that matrix loading is defined per unit cross-sectional area rather than per unit volume. This formulation of the independent variables allows the effects of matrix length and matrix cross section to be evaluated independently and avoids the implication that the effect on metallurgical performance of loading per unit matrix volume is independent of matrix canister shape. For example, it is unlikely that, for a given mass of retained magnetics, canister A of 10-m cross-sectional area (fig. 6) has retained over its 1-meter length the same distribution of magnetics that canister B of 1-m cross-sectional area has retained over its 10-meter length. In terms of the design and operating parameters, the retention time of the slurry in the matrix is equal to L/V. For a given rate of slurry flow through the matrix canister, the retention time is determined by the canister volume. If recovery is controlled by retention time, the shape of Device B (fig. 6) would be operated at 10 times the flow velocity of A to give the same capacity and recovery. For retention time to be a valid design concept, the exponents nl, and nv in equation 3 must be nearly equal. For the magnetic scavenging results that have been discussed, the exponent nv was more than twice nL. Thus, for a given magnetized volume, configuration A, with a large cross-sectional area and small bed depth, gives optimal recovery. In fact, even if nL and nv were equal, configuration A would give better performance, because, for a given volume of feed slurry treated, matrix loading per unit area would be less. In principle, device B could be converted to give the same performance as A if the matrix were divided into 1-meter segments, as shown in C, and a suitable flow distribution system were provided.

Models developed from bench-scale tests are valuable for designing pilot- or full-scale WHIM separators only when the larger machines offer the same degree of control over operating parameters that laboratory units do. One important feature lacking in many continuous units is control over flow velocity by means other than the natural resistance of the matrix bed. The Bureau of Mines pilot plant experience has indicated several other important features of effective separator design. The applied magnetic field should be reasonably uniform across the cross section of matrix through which the feed slurry and rinse water flow. Adequate provision should be made for rinsing the matrix with clean water in the high magnetic field region. The nonmagnetic , rinse, and magnetic products should be effectively separated. The design should avoid areas where particles can settle out and accumulate, such as flat-bottomed sections, regions of stagnant flow, and high-gradient regions outside of the matrix.

Probably the most important problem encountered with pilot- or full-scale WHIM separators is permanent retention of particles in the matrix. The effects may range from a slight decrease in recovery to complete clogging of the system. The first step in attempting to eliminate this problem is matching the matrix to the feed. The matrix elements should be spaced widely enough not to capture large particles by purely physical means. So as not to adversely affect magnetic capture of fine particles by excessive spacing of the matrix elements, it is advantageous to adapt the feed to the matrix by removing the oversized particles. Permanent retention of ferromagnetic particles in the matrix can be minimized by reducing magnetic flux leakage into the matrix flush zone and by choosing a matrix material of low coercivity and remanence. If a large proportion of ferromagnetics is present in the feed, it is desirable to use a conventional low-intensity magnetic separator before high-intensity separation. A critical factor for maintaining a clean matrix is a flush water velocity much higher than that of the feed slurry. For a given quantity of flush water, pulsating flow is preferable to steady flow; back-flushing is preferable to forward flushing. One of the most effective methods of assuring a clean matrix bed is to provide a method of agitating and rearranging the matrix elements.

WHIM separation, either alone or in combination with flotation, is a technically feasible method of processing the enormous resources of oxidized taconite in the Lake Superior region. Commercial feasibility depends upon continuing progress in the design and construction of effective, reliable, yet economical magnetic separators. Mathematical models of separator operation can be valuable aids to the development of optimal designs. However, over dependence on unconfirmed theoretical descriptions, extrapolation of purely empirical results, and neglect of certain practical aspects of separator design can all lead to costly errors. Rational design of a full-scale separator for a particular application requires a realistic phenomenological model, supplemented by a systematic program of laboratory and pilot plant experimentation.

To help assure an adequate supply of minerals to meet the Nations economic and strategic needs, the Bureau of Mines is conducting bench- and pilot-scale research using wet high-intensity magnetic (WHIM) separation to recover iron from oxidized taconites of the Lake Superior region. The advantages and disadvantages of WHIM separation in relation to other separation methods, the most recent innovations in WHIM flowsheet design, and the role of mathematical models in process optimization are discussed.

wet magnetic separation

wet magnetic separation

In essence, any magnetic separator operates on the basis of imparting a preferential magnetic force on particles of higher magnetic susceptibility which are to be separated from particles of lower magnetic susceptibility. A certain amount of directional deviation to the particles takes place thus allowing for collecting each category of particles separately.

In a separator operating on the principle of a vertically fed gap, those particles that pass through the central plane, or for that matter, the central zone, of the gap are subjected to zero or effectively near zero force of attraction all along their downward vertical path. Whereas, in case of a spheroidal medium, such zones, though of course do exist, are by no means continuous along the whole passage of the particle. They exist between each cluster of neighboring spheroids only.

wet high intensity magnetic separation equipment wet drum iron remover for kaolin feldspar ceramic slurry quartz

wet high intensity magnetic separation equipment wet drum iron remover for kaolin feldspar ceramic slurry quartz

Wet High Efficent Intelligence Iron Remover Wet High Intensity Magnetic Separator Company profile Foshan Wandaye Machinery Company Limited is a national high-tech enterprise,owns a number of invention patents, with research and development production,major products are: magnetic separator for non-metallic mineral raw materials, ceramic glaze, metal, plastics, food and all kinds of industries.The main products are: electromagnetic Slurry separator, electromagnetic powder machine, permanent magnetic separator vertical ring electromagnetic separator,vertical ring permanent magnetic separator and different sizes of magnetic plates, magnetic rod, drawer type magnetic separator etc; Our company possesses professional technical team and sophisticated laboratory,can be customized for magnetic separator. Wandaye Limited since 2014 get involved in domestic and international mineral processing engineering technology and the fields of whole line project design etc . Product characteristic A new model of separator with high efficiency. High intensity magnetic field. The temperature inside of the machine rises slowly. Running long time and the magnetic field intensity are not easy to decrease. Technology parameter Model 1000 750 WS500T2 - I W500SL X500 Magnetic field strength(T) 5 5 5 3 5 Input voltage(ACV) 380 380 380 380 380 Maximum output current(DCA) 2500 1400 1400 1400 1400 Maxiumum coil power(KW) 180 75 75 30 45 Insulation method E E E E E Cooling method Water cooling Water cooling Water cooling Water cooling Water cooling Magnetic lumen diameter(mm) 1000 750 530 530 530 Pipe size(mm) 200 150 100 100 100 yield(m/h) 80-120 30-70 30-60 20-50 20-50 demension(mm) 2710*2410*3500 2600*2000*3000 2200*1700*3000 1400*1700*2345 2000*1600*2800 Main machine weight(KG) 35000 16350 14100 6500 9580 Usage Applicable for 40-400 mesh feedstock of iron elimination Operation process After a few minutes later(you can set the time whatever you like depending on yourself condition),close the admission valve and slurry valve, open the back slurry valve to discharge the remaining slurry in the separator,then magnetic cutting, close the admission valve, slurry valve and back slurry valve, open the iron discharging valve to discharge the magnetic material which are absorbed on the magnetic media. Application scope Non-metallic mineral: It is used for purifying the non-metallic mineral such as quartz, feldspar and kaolin. Ferrous metals mineral: hematite, martite, limonite, siderite, chromite, polianite. Non-ferrous metals mineral:used for separatingwolframite from pyrope Rare earth ore:recycle tantalum-niobium ores and monazite. other industries:iron ore, effluent of power station disposal, disposal of contaminated chemical raw material. client producing photo as follow

Company profile Foshan Wandaye Machinery Company Limited is a national high-tech enterprise,owns a number of invention patents, with research and development production,major products are: magnetic separator for non-metallic mineral raw materials, ceramic glaze, metal, plastics, food and all kinds of industries.The main products are: electromagnetic Slurry separator, electromagnetic powder machine, permanent magnetic separator vertical ring electromagnetic separator,vertical ring permanent magnetic separator and different sizes of magnetic plates, magnetic rod, drawer type magnetic separator etc; Our company possesses professional technical team and sophisticated laboratory,can be customized for magnetic separator. Wandaye Limited since 2014 get involved in domestic and international mineral processing engineering technology and the fields of whole line project design etc .

Product characteristic A new model of separator with high efficiency. High intensity magnetic field. The temperature inside of the machine rises slowly. Running long time and the magnetic field intensity are not easy to decrease. Technology parameter

Operation process After a few minutes later(you can set the time whatever you like depending on yourself condition),close the admission valve and slurry valve, open the back slurry valve to discharge the remaining slurry in the separator,then magnetic cutting, close the admission valve, slurry valve and back slurry valve, open the iron discharging valve to discharge the magnetic material which are absorbed on the magnetic media. Application scope Non-metallic mineral: It is used for purifying the non-metallic mineral such as quartz, feldspar and kaolin. Ferrous metals mineral: hematite, martite, limonite, siderite, chromite, polianite. Non-ferrous metals mineral:used for separatingwolframite from pyrope Rare earth ore:recycle tantalum-niobium ores and monazite. other industries:iron ore, effluent of power station disposal, disposal of contaminated chemical raw material.

magnetic separation | multotec

magnetic separation | multotec

Multotec supplies a complete range of magnetic separation equipment for separating ferromagnetic and paramagnetic particles from dry solids or slurries, or for removing tramp metal. Multotec Dry and Wet Drum Separators, WHIMS, Demagnetising Coils and Overbelt Magnets are used in mineral processing plants across the world. We can engineer customised magnetic separation solutions for your process, helping you improve the efficiency of downstream processing and lower your overall costs of production.

Multotec provides a wide range of magnetic separators including: Permanent magnet Low Intensity Magnetic Separators (LIMS) or Medium Intensity Magnetic Separators (MIMS) and electromagnetic High Intensity Magnetic Separators (HIMS). Multotec provides unmatched global metallurgical expertise through a worldwide network of branches, which support your processing operation with turnkey magnetic separation solutions, from plant audits and field service to strategic spares for your magnetic separation equipment.

Whether you need to recover fast moving tramp metal, recover valuable metals in waste streams or enhance the beneficiation of ferrous metals, Multotec has the magnetic separator you require. Dry drum cobber magnetic separators provide an initial upgrade of feed material as well as a gangue material rejection stage. By improving the material fed to downstream plant processes, our magnetic separation solutions reduce the mechanical requirements of grinding, ultimately lowering overall costs. Our heavy media drum separators are ideally suited for dense media separation plants. Our ferromagnetic wet drum separators can be used in iron ore separation plants in both rougher or cleaner beneficiation applications. We also provide demagnetising solutions that reverse the residual effects that magnetic separation has on the magnetic viscosity of ferrous slurries, to return the mineral stream to an acceptable viscosity for downstream processing. These demagnetising coils generate a magnetic field that alters magnetic orientation at 200 Hz.

The trend towards larger and faster travelling conveyors in the African mining industry has highlighted the vital role of overbelt magnets. Solutions need to be optimised to such factors as belt speed and width, the belt troughing angle, the burden depth, the material density and bulk density, the expected tramp metal specifications, ambient operating temperatures and suspension height to provide maximum plant and cost efficiency. Multotec can supply complete overbelt magnet systems, from equipment supply to a turnkey service by means of its strategic partners, including even the gantry work.

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