Enrichment of a Nigerian chromite ore for metallurgical application by dense medium flotation and magnetic separation

2019 ◽  
Vol 116 (3) ◽  
pp. 324 ◽  
Author(s):  
Kuranga Ibrahim Ayinla ◽  
Alafara Abdullahi Baba ◽  
Bankim Chandra Tripathy ◽  
Malay Kumar Ghosh ◽  
Rajan Kumar Dwari ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Separation ◽  
Organic Liquid ◽  
Size Fraction ◽  
Dense Medium ◽  
Chromium Alloy ◽  
Magnetic Separator ◽  
Electro Deposition ◽  
Chromite Ore ◽  
Wet Chemical

This study, focused on the beneficiation of a Nigerian complex chromite ore sourced from Tunga-Kaduka, Anka Local Government of Zamfara State, Nigeria, assaying 45.85% Cr2O4 and 54.15% mineral impurities, was enriched concurrently through sink floatation and magnetic separation techniques. The chromite ore initially analyzed to contain silicate impurities was found not suitable for metallurgical purposes. Thus, enrichment was examined through gravity separation studies using organic liquid with different specific gravities at 2.8, 3.3, and 4.0. The separation of chromite ore with lowest particle size fraction was done using Mozley mineral separator followed by the magnetic separation of the sink product by magnetic separator. The results obtained revealed about 77% of the total material containing 300 μm particle size, 52% ˂ 212 μm and 17% below 75 μm. Subsequent analysis of the beneficiated ore was carried out by wet chemical analysis and atomic absorption spectrophotometer. The results showed that Cr2O4 content increased to 78.34% from initial 45.83% with maximum Cr:Fe ratio of 3.2:1, representing 84.27% of chromium metal present in the ore. The enrichment of Cr2O4 obtained in this study could be found metallurgically applicable in the electro-deposition and ferro-chromium alloy production practices.

scholarly journals Dry magnetic separation technology for the recovery of iron minerals in fine-grained steel slag

2020 ◽  
Vol 40 (1) ◽  
pp. 7-16
Author(s):  
Liang Chang Shi ◽  
Nan Sheng Wang ◽  
Gan Cheng
Keyword(s):  
Particle Size ◽  
Magnetic Separation ◽  
Steel Slag ◽  
Separation Distance ◽  
Magnetic Separator ◽  
Separation Technology ◽  
Fine Grained ◽  
Dry Magnetic Separation ◽  
Concentrate Grade ◽  
Parameter Values

Using the MagNet software package, a permanent magnetic circuit was simulated and a sectorially-spliced magnetic system was designed. Consequently, a new roller permanent magnetic separator with different magnetic field intensities in each roller was developed. The modular structural design allows fine-grained minerals with different magnetic susceptibility to be separated in one pass, according to their different processing characteristic. Steel slag, selected from a factory, was crushed, ground and sieved into different particle size ranges for the single-factor magnetic separation experiments. It was determined that the optimum value ranges for the particle size, magnetic separation distance and rotating frequency were 0.15 mm-0.3 mm, 10 mm-12 mm, 40 Hz～60Hz, respectively; using the chosen parameter values of 0.2mm, 11mm, and 40Hz, the concentrate recovery and concentrate grade of the new separation technology reached up to 52.78% and 64.74%, in comparisson with the existing technology. Thus, it was demonstrated that the self-developed separation technology has the potential to improve the iron recovery of the fine-grained steel slag.

scholarly journals Effect of Mineralogy on the Beneficiation of REE from Heavy Mineral Sands: The Case of Nea Peramos, Kavala, Northern Greece

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 387 ◽  
Author(s):  
Christina Stouraiti ◽  
Vassiliki Angelatou ◽  
Sofia Petushok ◽  
Konstantinos Soukis ◽  
Demetrios Eliopoulos
Keyword(s):  
Particle Size ◽  
Magnetic Separation ◽  
Size Fraction ◽  
Heavy Mineral ◽  
Magnetic Fraction ◽  
High Concentration ◽  
Northern Greece ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Icp Ms

Beneficiation of a rare earth element (REE) ore from heavy mineral (HM) sands by particle size classification in conjunction with high-intensity magnetic separation (HIMS) was investigated. The HM sands of Nea Peramos, Kavala, Northern Greece, contain high concentrations of REE accommodated mainly in silicate minerals, such as allanite. However, the potential of the Northern Greek placer for REE exploitation has not been fully evaluated due to limited on-shore and off-shore exploration drilling data. Characterization of the magnetic separation fractions using XRD and bulk ICP-MS chemical analysis showed that the magnetic products at high intensities were strongly enriched in the light REE (LREE), relative to the non-magnetic fraction. Allanite and titanite are the major host mineral for REE in the magnetic products but mainly allanite controls the REE budget due its high concentration in LREE. SEM/EDS and ICP-MS analysis of the different particle size fractions showed LREE enrichment in the fractions −0.425 + 0.212 mm, and a maximum enrichment in the −0.425 + 0.300 mm. The maximum enrichment is achieved after magnetic separation of the particle size fractions. Mass balance calculations showed that the maximum REE recovery is achieved after magnetic separation of each particle size fraction separately, i.e., 92 wt.% La, 91 wt.% Ce, and 87 wt.% Nd. This new information can contribute to the optimization of beneficiation process to be applied for REE recovery from HM black sands.

scholarly journals Beneficiation of Low-Grade Rare Earth Ore from Khalzan Buregtei Deposit (Mongolia) by Magnetic Separation

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1432
Author(s):  
Ilhwan Park ◽  
Yuki Kanazawa ◽  
Naoya Sato ◽  
Purevdelger Galtchandmani ◽  
Manis Kumar Jha ◽  
...  
Keyword(s):  
Particle Size ◽  
Rare Earth ◽  
Magnetic Separation ◽  
High Intensity ◽  
Carbon Dioxide Emission ◽  
Size Fraction ◽  
Ore Deposits ◽  
Enrichment Ratio ◽  
Low Grade ◽  
Particle Size Fraction

The global demand for rare earth elements (REEs) is expected to increase significantly because of their importance in renewable energy and clean storage technologies, which are critical for drastic carbon dioxide emission reduction to achieve a carbon-neutral society. REE ore deposits around the world are scarce and those that have been identified but remain unexploited need to be developed to supply future demands. In this study, the Khalzan Buregtei deposit located in western Mongolia was studied with the aim of upgrading low-grade REE ore via magnetic separation techniques. The total REE content in this ore was ~6720 ppm (~3540 ppm light REE (LREE) + ~3180 ppm heavy REE (HREE)) with bastnaesite, pyrochlore, synchysite, and columbite-(Fe) identified as the main REE-bearing minerals. As the particle size fraction decreased from −4.0 + 2.0 mm to −0.5 + 0.1 mm, the recovery by dry high-intensity magnetic separation (DHIMS) increased from 20% to 70% of total rare earth oxide (TREO) while the enrichment ratio reached 2.8 from 1.3. Although effective, gangue minerals such as quartz and aluminosilicates were recovered (~22%) due most likely to insufficient liberation. Meanwhile, the wet high-intensity magnetic separation (WHIMS) could produce a magnetic concentrate with TREO recovery of ~80% and enrichment ratio of 5.5 under the following conditions: particle size fraction, −106 + 75 μm; feed flow rate, 3.2 L/min; magnetic induction, 0.8 T. These results indicate that combining DHIMS and WHIMS to upgrade the low-grade REE ore from the Khalzan Buregtei deposit is an effective approach.

Particle Size Effects on Concentration of Metals in Lake Erie Bottom Sediments

1984 ◽  
Vol 19 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Alena Mudroch
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Clay Minerals ◽  
Surface Sediment ◽  
Size Effects ◽  
Lake Erie ◽  
Size Fraction ◽  
Mineralogical Composition ◽  
Major Elements ◽  
Sediment Samples

Abstract Surface sediment samples obtained at the offshore and nearshore area of Lake Erie were separated into eight different size fractions ranging from <2 µm to 250 µm. The concentration of major elements (Si, Al, Ca, Mg, K, Na, Fe, Mn and P), metals (Zn, Cu, Cr, Ni, V, Co and Pb) and organic matter was determined together with the mineralogical composition and morphology of the particles in each size fraction. The distribution of the metals in the offshore sediment was bimodal with the majority of the metals divided between the 63 to 250 um size fraction which also contained the highest concentration of organic matter (about 20%) and the <4 µm fraction containing up to 60% of clay minerals. However, the metals in the nearshore sediment were associated mainly with the clay minerals.

scholarly journals The Processing of Beach Sand from Sri Lanka for the Recovery of Titanium Using Magnetic Separation

2003 ◽  
Vol 12 (1) ◽  
pp. 13-22 ◽  
Author(s):  
W. A. P. J. Premaratne ◽  
N. A. Rowson
Keyword(s):  
Particle Size ◽  
Sri Lanka ◽  
Chemical Analysis ◽  
Titanium Content ◽  
Beach Sand ◽  
Magnetic Fraction ◽  
Chemical Characteristics ◽  
Magnetic Separator ◽  
Commercial Grade ◽  
Sand Deposit

An investigation has been carried out to study the mineralogical and chemical characteristics of beach sand deposits from Sri Lanka and application and optimisation of different magnetic separators (induced roll magnetic separator and disc magnetic separator) to improve the recovery of titanium from the deposit. Commercial grade titanium concentrates could be achieved employing both induced roll and disc magnetic separators. However, the titanium recovery increased greatly in the magnetic fraction with a titanium content of commercial grade (up to 63.9% TiO2) when paramagnetic titanium-bearing minerals were separated from beach sand using the disc magnetic separator. The results of the mineralogical and chemical analysis tests for the beach sand deposit indicated that 71% of beach sand was smaller than 355 μm in particle size and more than 99% of titanium content of the deposit was contained in this fraction.

scholarly journals Long term trends in fertility of soils under continuous cultivation and cereal cropping in southern Queensland. III. Distribution and kinetics of soil organic carbon in particle size fractions

Soil Research ◽  
1986 ◽  
Vol 24 (2) ◽  
pp. 293 ◽  
Author(s):  
RC Dalal ◽  
RJ Mayer
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Size Fraction ◽  
Organic C ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Clay Size Fraction ◽  
Sand Size

Distribution of soil organic carbon in sand-, silt- and clay-size fractions during cultivation for periods ranging from 20 to 70 years was studied in six major soils used for cereal cropping in southern Queensland. Particle-size fractions were obtained by dispersion in water using cation exchange resin, sieving and sedimentation. In the soils' virgin state no single particle-size fraction was found to be consistently enriched as compared to the whole soil in organic C in all six soils, although the largest proportion (48%) of organic C was in the clay-size fraction; silt and sand-size fractions contained remaining organic C in equal amounts. Upon cultivation, the amounts of organic C declined from all particle-size fractions in most soils, although the loss rates differed considerably among different fractions and from the whole soil. The proportion of the sand-size fraction declined rapidly (from 26% to 12% overall), whereas that of the clay-size fraction increased from 48% to 61% overall. The proportion of silt-size organic C was least affected by cultivation in most soils. It was inferred, therefore, that the sand-size organic matter is rapidly lost from soil, through mineralization as well as disintegration into silt-size and clay-size fractions, and that the clay fraction provides protection for the soil organic matter against microbial and enzymic degradation.

Distribution of total bacteria and staphylococci in PM2.5, PM10 and total dust in the emission of two fattening pig houses/Verteilung von Gesamtbakterien und Staphylokokken in PM2,5, PM10 und Gesamtstaub in der Emission von zwei Mastschweineställen

Gefahrstoffe ◽  
2020 ◽  
Vol 80 (09) ◽  
pp. 344-348
Author(s):  
M. Clauß ◽  
S. Linke ◽  
A. C. Springorum
Keyword(s):  
Particle Size ◽  
Size Fraction ◽  
Airborne Bacteria ◽  
Dispersion Modelling ◽  
Particle Size Fraction ◽  
Collection System ◽  
Total Dust ◽  
Dust Distribution ◽  
Selective Collection ◽  
Total Bacteria

The particle size distribution of airborne bacterial conglomerates is an important factor in calculating possible spread distances of the bacteria over the air. Therefore, a size-selective collection system based on an emission impinger was developed to compare the distribution of total bacteria and staphylococci in particle fractions PM2.5, PM10 and total dust in the emission of two fattening pig stables. Mean emissions of 7.2 × 104 cfu/m³ total bacteria, 6.1 × 104 cfu/m³ staphylococci and 2.8 × 106 cells/m3 measured. About 30% of total bacteria and staphylococci were found in the PM2.5 particle size fraction and about 60% in PM10. The average dust distribution was 80% PM10 and 60% PM2.5. The results show that airborne bacteria from fattening pig units mainly occur on larger particles and do not correlate with dust fractions. The found conditions should be considered in future dispersion modelling.

Structural and Magnetic study of Al3+ doped Ni0.75Zn0.25Fe2-xAlxO4 nanoferrites

2013 ◽  
Vol 1506 ◽  
Author(s):  
L. Wang ◽  
B. K. Rai ◽  
S. R. Mishra
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Chemical Method ◽  
X Ray Diffraction ◽  
Wet Chemical Method ◽  
X Ray ◽  
Transmission Electron ◽  
Magnetic Dilution ◽  
Wet Chemical ◽  
Structural And Magnetic Properties

AbstractNanostructured Al3+ doped Ni0.75Zn0.25Fe2-xAlxO4 (x = 0.0,0.2,0.4,0.6,0.8, and 1.0) ferrites were synthesized via wet chemical method. X-ray diffraction, transmission electron microscopy, and magnetization measurements have been used to investigate the structural and magnetic properties of spinel ferrites calcined at 950 °C .With the doping of Al3+, the particle size of Ni0.75Zn0.25Fe2-xAlxO4 first increased to 47 nm at x = 0.4 and then decreased down to 37 nm at x = 1. Saturation magnetization decreased linearly with Al3+ due to magnetic dilution. The coercive field showed an inverse dependence on the particle size of ferrites.

scholarly journals Effect of Soil Washing Using Oxalic Acid on Arsenic Speciation and Bioaccessibility in Soils

2020 ◽  
Vol 42 (4) ◽  
pp. 218-227
Author(s):  
Yeseul Gwon ◽  
Seong Ryeol Kim ◽  
Eun Jung Kim
Keyword(s):  
Particle Size ◽  
Oxalic Acid ◽  
Contaminated Soil ◽  
Arsenic Speciation ◽  
Arsenic Concentration ◽  
Size Fraction ◽  
Soil Washing ◽  
Large Particle Size ◽  
Amorphous Oxides ◽  
Particle Size Fractions

Objectives : Soil washing process has been widely applied for remediation of contaminated soil with arsenic and heavy metals in Korea. The application of soil washing could change physical and chemical properties of soils and metal speciation in soil, which could affect the risk to the environment and human health. Thus, it is necessary to evaluate metal and arsenic speciation and their mobility in soil after soil remediation in order to evaluate effectiveness of soil remediation process and manage soil quality effectively. The purpose of this study is to evaluate the risk of arsenic in soil after remediation of arsenic contaminated soil via soil washing.Methods : Arsenic contaminated soil collected at the abandoned mine site was washing with oxalic acid. The arsenic contaminated soil was divided into 2,000-500 µm, 500-250 µm, 250-150 µm, 150-75 µm, 75-38 µm, < 38 µm particle size fractions. After soil washing for each soil particle size fraction, arsenic speciation via sequential extraction and bioaccessibility in the soils were evaluated. Results and Discussion : Generally, arsenic and metal concentrations were higher in the soil fractions with smaller particle sizes. But high arsenic concentration was observed at the large particle size fractions (>250 µm), which might be due to the presence of mineral phases containing arsenic such as arsenolite or pyrite in the large particle size fraction soils. Sequential extraction showed that arsenic in mine soils was majorly present as associated with amorphous oxides. After soil washing with oxalic acid, arsenic in soils associated with amorphous oxides was greatly decreased, whereas the arsenic fraction associated sulfide and organic matter was increased. Soil washing decreased the bioaccessible arsenic concentration (mg/kg) in soil, but increased the bioaccessibility (%) depending on the soil characteristics. Conclusions : Soil washing changed arsenic species in soils, which affected mobility and risk of arsenic in soil.

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