High Intensity Magnetic Separation Research Articles

Recovery of high grade iron compounds from LD slag by enhanced magnetic separation techniques

A representative sample of LD slag provided from French steel industry was treated by different physical separation techniques especially used in mineral processing. The results of characterisation study show that the LD slag may contain up to 35% of iron compounds. The X-ray diffraction reveals the presence of the following crystallized mineral phases: CaO, MgO, Al2O3, SiO2, MnO, and P2O5. Larnite (Ca2SiO4), di-calcium aluminoferrite (brownmillerite: Ca2Fe2−xAlxO5 with x=0.6) and a solid solution (Fe, Mn, Mg)O structurally close to the wüstite (FeO) and some residual lime (CaO).The results of grinding tests show that the manner of grinding is very important. Soft Grinding (SG) or sequential grinding is most suitable to reduce the particle size of LD slag avoiding the overproduction of fine particles, which hinder the effectiveness of magnetic separation techniques. The combination of Low and High Intensity Magnetic Separation (LIMS and HIMS) of ground LD slag at 63μm in wet process may recover ferromagnetic particles (iron oxides) at LIMS and paramagnetic particles at HIMS, while the non-magnetic fraction contains mostly calcium silicates.From this investigation, two flow-sheets of treatment of LD slag are suggested to recover high grade iron material for recycling in metallurgical processes. Calcium and silicon oxide rich product will be directed to the cement industry.

Experimental Study of Flotation on High Intensity Magnetic Concentrates of Ilmenite

In order to improve the separating index of ilmenite to separate the concentrate by high intensity magnetic separation, the Heishan iron ore in Chengde did some work. Separate the sulfide ore out by flotation under the conditions of concentration by weight in feed 32%, consumption of xanthate 200g/t and 2# oil 40g/t. Use sulfate to adjust the pH of the low sulphur product of flotation, the mixture of EM351-2 and EM351-3 as foaming agent, after one roughinging and four fold concentrating, got the final titanium concentrate, the grade of which is 47.23%, and the recovery is 58.29%. During the procedure of roughing, the consumption of the reagent as follows: sulfate 2kg/t, EM351-3 1kg/t, EM351-2 900g/t. The consumption of sulfate during fourfold concentrating is 1kg/t. The index is more stable when the concentration in feed is 18%~26% during flotation. The index is stable during the continuous 26 work time for the process under this reagent system. The screen analysis of the flotation concentrate indicates that this reagent system has a better effect on the flotation of +0.074mm particles, and a bad effect on the flotation of-0.045mm particles.

Glass Sand Processing Techniques in the Rayong Area, Thailand

This article discusses the beneficiation of glass sand at Rayong province in the eastern part of Thailand . The process consists of revolving screen, hydrocyclone, attrition scrubber, tank classifier, spiral concentrator, wet high intensity magnetic separator and closed loop water recycling system. There are 13 glass sand processing plants in this area with the overall capacity 2 million tons per year and supply glass sand to float glass and flat glass industry, glassware industry, glass packaging industry, ceramic industry and chemical industry in Thailand. Keywords: Glass sand, Revolving screen, Hydrocyclon, Attrition scrubber, Tank classifier, Spiral concentrator, Wet high intensity magnetic separator, Closed loop water recycling system.

Research on Separating Low-Grade K-Feldspar from Quartz without Hydrofluoric Acid

Flotation technology without fluorite was studied to separate low-grade K-feldspar with quartz. It is shown in the results that qualified K-feldspar concentrate can be gained by grinding, desliming, flotation and high intensity Magnetic Separation process. Feldspar concentrate obtained in closed-circuit had a content of K2O and Na2O 12.12%, quartz concentrate with a yield of 19.94% containing 97.12% SiO2 was obtained in the same time.

Processing a rare earth mineral deposit using gravity and magnetic separation

Rare earth (RE) mineral deposits are typically processed using several different unit operations including flotation, gravity, magnetic and electrostatic separation techniques. Two of the most important beneficiation techniques for RE minerals are gravity and magnetic separation. Many RE minerals are found alongside low specific gravity gangue minerals thereby permitting the use of gravity separations to concentrate the heavy value RE minerals. Magnetic separation is used primarily to remove ferromagnetic gangue minerals as well as to separate individual paramagnetic rare earth minerals.This work investigated the use of a wet high intensity magnetic separation (WHIMS) in conjunction with gravity pre-concentration steps (Knelson and Falcon centrifugal concentrators) to beneficiate a rare earth ore. The results of these separation steps are related to the magnetic properties of RE minerals, based on literature and measurements conducted using a vibrating sample magnetometer (VSM).

Test Research on HIMS-Reverse Flotation of Oolitic Hematite of Longyan Iron Mine

In order to better exploit and utilize the oolitic hematite ore resource in Zhangjiakou region, staged grinding-separation process consisting of high intensity magnetic separation(HIMS) and reverse floatation was adopted in the beneficiation test on the regionally representative oolitic hematite ore of Longyan Iron Mine, Xuan Stee1. The test results indicate that，with Slong pulsating high gradient magnetic separation as HIMS equipment，with NaOH，starch，CaO and TS as flotation reagents，and at a grind of 65％ -200 mesh for the primary grinding and 95％-200 mesh for the secondary grinding，an iron concentrate grading 62.34％ and having an iron recovery of 53.07％ can be achieved after two stage HIMS and one roughing—one cleaning reverse flotation.

Characterization and beneficiation of iranian low-grade manganese ore

The mineralogical studies indicated that Charagah ore deposit contains approximately 17% pyrolusite, 78% calcite and 3-4% quartz. Pyrolusite as a main valuable mineral is found in the forms of coarse and fine pyrolusites. The coarse grains pyrolusite with simple texture is liberated at 180 microns. Another kind of pyrolusite with particle size finer than 10 m is disseminated inside gangue phases. This kind of pyrolusite has important effect in beneficiation processes and can affect the manganese grade of the concentrate and its recovery negatively. By jigging machine a pre-concentrate with 20% MnO and a final tailing with about 13% manganese loss are obtained. Using tabling technique or wet high intensity magnetic separation (WHIMS) and also their combination with jigging machine, production of a final pyrolusite concentrate with suitable grade but average recovery is possible. By jigging-tabling a concentrate with -500+45 m size fraction, 44.3% MnO and 61.3% recovery is obtained while jigging- WHIMS produces a concentrate containing 52.6% MnO with a recovery up to 56.6% and d80 = 180 m.

Separating the Anshan-Type Low-Grade Hematite Ore with Process of Gravity-Magnetic Method

According to the nature of the ore which containing hematite and magnetite,under the conditions,for example,ore grade is 24.07%,the first fineness of grinding -200 mesh is 50%，the second fineness of grinding -200 mesh is more than 95%, it is concluded that concentrating circuit consisting of first grind-Feebleness magnetic separation -high intensity magnetic separation，second grind-second-high intensity magnetic separation-shaking tables. Ultimately, A concentrate with a productivity of 19.35%，a grade of 65.89% TFe and the recovery of 52.32%was yielded.

Beneficiation Process Optimization Study on a Low-Grade Hematite Ore

A hematite has low grade, fine disseminated size andcomplex disseminated relations, which are refractory iron ore. Using SLon pulsating high gradient magnetic separator, induction intensity 8500Oe, pulsating 20mm stroke, stroke of 120 beats / min), a crude iron ore concentrates a grade of 35.93.%, the recovery rate of 82.39% is obtained through high intensity magnetic separation.( The final iron concentrate with TFe grade of 64.83%,yield of 14.55% and iron recovery of 35.74% from the raw ores with TFe grade of 26.29％ was obtained, with the first stage grinding size being 50% -0.074mm and the second stage,95% -0.074mm.

High intensity magnetic separation for the clean-up of a site polluted by lead metallurgy

The industrial history in the district of Linares (Spain) has had a severe impact on soil quality. Here we examined soil contaminated by lead and other heavy metals in “La Cruz” site, a brownfield affected by metallurgical residues. Initially, the presence of contaminants mainly associated with the presence of lead slag fragments mixed with the soil was evaluated. The subsequent analysis showed a quasi-uniform distribution of the pollution irrespective of the grain-size fractions. This study was accompanied by a characterization of the lead slag behavior under the presence of a magnetic field. Two main magnetic components were detected: first a ferromagnetic and/or ferrimagnetic contribution, second a paramagnetic and/or antiferromagnetic one. It was also established that the slag was composed mainly of lead spherules and iron oxides embedded in a silicate matrix. Under these conditions, the capacity of magnetic separation to remove pollutants was examined. Therefore, two high intensity magnetic separators (dry and wet devices, respectively) were used. Dry separation proved to be successful at decontaminating soil in the first stages of a soil washing plant. In contrast, wet separation was found effective as a post-process for the finer fractions.

Recovering Limonite by High Intensity Magnetic Separation Technology from Honghe Limonite Ore

High intensity magnetic separation tests have been carried out on the oolitic limonite ore with complex relations between limonite and gangue minerals of Honghe prefecture, and a optimal flowsheet for recover limonite from run-of-mine was adopted at last. High intensity magnetic separation flowsheet with one stage rougher, cleaner and scavenger, which have been studied respectively. Iron concentrate containing 55.18%Fe could be obtained at yield of 53.20% and recovery of Fe 68.45 % in closed circuit test.

Research on Classified Magnetic Separation of Oolitic Hematite from Guizhou Province

Oolitic hematite is considered to be one of the most refractory ores in the world due to its ultra fine disseminated grain size and complex mineral composition. Various magnetic separation methods were conducted on the oolitic hematite ore samples from Guizhou Province. Because the TFe grades of each size fraction of the grinding products were different from each other, the beneficiation process of “classification – low intensity magnetic separation – high intensity magnetic separation” was finally adopted to guarantee the quality of iron concentrates. After the determined magnetic separation, the relatively good technical indexes are obtained. The TFe grade of iron concentrates is increased from 38.7% to 46.1%, and the iron recovery is 81.7%.

Experimental Research on Flotation Separation of a Kyanite Rough Concentrate in Hebei Province

Kyanite is a kind of andalusite minerals, with good refractory. In nature, it existed together with mica, quartz etc, so it is necessary to purify. Garnet kyanite schist in Hebei province as the raw ore was separated in this paper, on the basement of high intensity magnetic separation and gravity to demilish impurities, obtain kyanite rude concentrate, by proceed a series of flotation condition test research, through six- concentrate reelection, getting the flotation concentrate with grade of 56.16%,the productivity of 12.09%,the recovery of 36.82%. Meanwhile, the reason of the low concentrate grade was analysed, and the suggestion was given to deal with kyanite concentrate in the next step. It provided foundation date for the developing of kyanite separation.

Recovery of Iron Bearing Minerals from Beneficiation Plant 2 Thickner Underflow of JSW Steel Limited

To identify and establish beneficiation techniques for slime, a comprehensive research work was carried out on beneficiation plant 2 thickener underflow (Tailing). Iron ore slimes (-45 micron ~80.0%) generated at beneficiation plant 2 assaying 46.7% Fe, 10.82% SiO2, and 4.58% Al2O3 have been subjected to various beneficiation studies like cyclone, wet high intensity magnetic separator and flotation to recover the iron bearing minerals. The effects of different operating parameters have been studied to get a product suitable for pellet making. Detailed beneficiation studies indicate that it is possible to obtain a product containing 61.8% to 66.6% Fe, 1.80% to 3.35% SiO2, and 1.65% to 2.40% Al2O3 with 8.0% to 22.3% weight recovery by adopting de-sliming followed by magnetic separation. Within this product grade range the pellet grade fines (JSW norms-minimum 63.0% Fe) consist of 63.0% Fe, 2.97% SiO2 and 2.48% Al2O3 with 16.9% weight recovery and 56.9% Fe recovery at 0.5 Tesla magnetic field intensity, pulsation rate 230 rpm and 2 min residence time.

Study on Process Mineralogy and Concentrating of a Certain Kyanite Ore in Xingtai

To identify the process mineralogical properties of kyanite from Heibei so as to provide a mineralogical basis for its chemical composition, mineral constituent，ores texture and structure and so on . The results show that: the kyanite Al2O3 21.50%, SiO2 52.87%, using high intensity magnetic separation —gravity separation— flotation folwsheet. Experiments show that, the grinding fineness of -0.074mm 65%, with strong intensity magnetic separation, magnetic concentrate by shaking the low intensity magnetic separation，we can get magnetite, garnet, biotite and phlogopite four concentrates, strong magnetic ore tailings consolidated by a rocking bed mud thrown first, refined through a coarse fine two shake, shake in after a rough featured a parted, won the 60.38% grade of Kyanite concentrate and 85% grade quartz ore.

Experimental Study on the Mineral Processing of a High-Clay and Lean Hematite

The mineral processing experimental research was carried out on a high mud content lean hematite. The results showed that using the technological flowsheet of “stage grinding- low intensity magnetic separation for obtaining concentrate - high-intensity magnetic separation for discarding tailings-gravity separation(shaking table)”,a final iron concentrate with TFe grade of 65.89% ,yield of 19.35% and iron recovery of 52.32% from the raw ores with TFe grade of 24.07％ was obtained, with the first stage grinding size being 50% -200 mesh and the second stage,95% -200 mesh.

Experimental Research on Mineral Processing Technique of a Brazilian Specularite

Laboratory research on the mineral processing technique of a specularite ore from Baxi was performed, while the processes including gravity separation, low intensity magnetic separation(LIMS) -high intensity magnetic separation(HIMS)-gravity separation was adopted. The run-of-mine ore was milled till the -0.074 mm range accounts for 50% and treated through a LIMS – HIMS process, with the magnetic field strength of LIMS being 95.52 kA/m and HIMS,1.2T. As a result, an iron concentrate grading about 67.58% at a recovery of 96.21% can be obtained, which are rather good metallurgical performances. The iron concentrate with high grade also could be beneficiated by table separation, but its recovery is lower than it obtained from intensive LIMS – HIMS dressing.

Comprehensive Utilization Study of Iron Tailings

It's is very effective using high intensity magnetic separation and low intensity magnetic separation to process magnetite tailings. The best fineness for separation is -0.045mm 85%. The concentrate contains Fe 67.86% under 0.2T field intensity. Processing the tailings twice under 0.5T field intensity, the concentrate contains Fe 55.06%.The total recovery is 53.72%. The study on low-grade iron ore tailings to recover iron achieves good results in improving resource utilization.

Recovery Improvement of Fine Magnetic Particles by Floc Magnetic Separation

The performance of floc magnetic separation (FMS) has been compared with wet high-intensity magnetic separator (WHIMS). This study was performed on low-grade iron ore slime contained 59.58% Fe with 4.57% silica and 3.78% alumina. Detailed characterization data indicated that a substantial amount of the slime was below 20 µm in size. Beneficiation studies indicated that the FMS process is effective to recover fine hematite and goethite particles, compared with the conventional magnetic separation. In conventional magnetic separation, the extent of the fluid drag force exceeds the magnetic force exerted on ultrafine particles. Thus, ultrafine magnetic particles were usually not recovered effectively by magnetic separators, resulting in the loss of valuable ultrafine slime particles. The FMS process significantly increases the magnetic force on the ultrafine iron ore in the form of hydrophobic flocs in a magnetic field, thus the ultrafine particles can be picked up effectively as magnetic concentrates. The FMS process improved the Fe recovery from 37.35% to 79.60%.

Analysis of Wet High-Intensity Magnetic Separation of Low-Grade Indian Iron Ore using Statistical Technique

The particle separation in a wet high-intensity magnetic separator depends on a number of variables. Applied magnetic field, particle size, and wash water rate play a vital role among them. Influences of these important variables were studied in detail following 33 full factorial designs of experiments using a laboratory/pilot-scale wet high-intensity magnetic separator (Gaustec G-340 Minimag). Statistical analysis of the results indicated that the influence of all these variables are significant (95% confidence level) on the recovery of magnetics and the order of significance follows, particle size > magnetic field > wash water rate. The experimental results used to develop the regression models to predict yield and grade at unknown operating conditions in the study range. Investigations carried out on a wet high-intensity magnetic separator using a low-grade iron ore sample containing 49.27% Fe shows that it is possible to upgrade to 62% Fe in the concentrate with poor yield values. A “tree” procedure (generally used to evaluate the flotation performance) was followed to evaluate maximum possible yield and grade by the magnetic separator. The “tree” procedure results provide useful information about the magnetic separation competence.