scholarly journals Improving the Quality of Ferruginous Chromite Concentrates Via Physical Separation Methods

Minerals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 667 ◽  
Author(s):  
Sunil Tripathy ◽  
Y Murthy ◽  
Veerendra Singh ◽  
Saeed Farrokhpay ◽  
Lev Filippov
Keyword(s):  
Magnetic Separation ◽  
Chromium Content ◽  
Detailed Characterization ◽  
Physical Separation ◽  
Chromite Ore ◽  
Chromite Concentrate ◽  
Automated Mineralogy ◽  
Characterization Studies

The low chromium-to-iron ratio of chromite ores is an important issue in some chromite deposits. The value of the chromite ore is indeed dictated in the market by its iron, as well as its chromium content. In the present study, a chromite concentrate was reprocessed by gravity (spiral concentrator) and magnetic separation to enhance the chromium-to-iron ratio. Also, detailed characterization studies including automated mineralogy were carried out to better understand the nature of the samples. Enhancing the chromium-to-iron ratio was achieved by using advanced spiral separators which will be discussed in this paper.

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 An updated detailed characterization of planes of satellites in the MW and M31

2020 ◽  
Vol 499 (3) ◽  
pp. 3755-3774
Author(s):  
Isabel M Santos-Santos ◽  
Rosa Domínguez-Tenreiro ◽  
Marcel S Pawlowski
Keyword(s):  
Milky Way ◽  
Velocity Dispersion ◽  
Local Group ◽  
Normal Density ◽  
Detailed Characterization ◽  
Kinematic Data ◽  
Positional Analysis ◽  
Form Part

ABSTRACT We present a detailed characterization of planes of satellite galaxies in the Milky Way (MW) and M31. For a positional analysis, we introduce an extension to the ‘4-galaxy-normal density plot’ method from Pawlowski, Kroupa & Jerjen. It finds the normal directions to the predominant planar configurations of satellites of a system, yielding for each a collection of planes of increasing member satellites. This allows to quantify the quality of planes in terms of population (Nsat) and spatial flattening (c/a). We apply this method to the latest data for confirmed MW and M31 satellite samples, with 46 and 34 satellites, respectively. New MW satellites form part of planes previously identified from a smaller sample of Nsat= 27: we identify a new plane with Nsat = 39 as thin as the VPOS-3 (c/a ∼ 0.2), and with roughly the same normal direction; so far the most populated plane that thin reported in the Local Group. We introduce a new method to determine, using kinematic data, the axis of maximum co-orbitation of MW satellites. Interestingly, this axis approximately coincides with the normal to the former plane: $\ge 45\pm 5{{\ \rm per\ cent}}$ of satellites co-orbit. In M31 we discover a plane with Nsat = 18 and c/a ∼ 0.15, i.e. quality comparable to the GPoA, and perpendicular to it. This structure is viewed face-on from the Sun making it susceptible to M31 satellite distance uncertainties. An estimation of the perpendicular velocity dispersion suggests that it is dynamically unstable. Finally we find that mass is not a property determining a satellite’s membership to good quality planes.

Processing of Ferruginous Chromite Ore by Dry High-Intensity Magnetic Separation

2016 ◽  
Vol 37 (3) ◽  
pp. 196-210 ◽  
Author(s):  
Sunil Kumar Tripathy ◽  
Y. Rama Murthy ◽  
Veerendra Singh ◽  
Nikkam Suresh
Keyword(s):  
Magnetic Separation ◽  
High Intensity ◽  
Chromite Ore

scholarly journals Development of a Physical Separation Route for the Concentration of Base Metals from Old Wasted Printed Circuit Boards

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1014
Author(s):  
Pedro Jorge Walburga Keglevich de Buzin ◽  
Weslei Monteiro Ambrós ◽  
Irineu Antônio Schadach de Brum ◽  
Rejane Maria Candiota Tubino ◽  
Carlos Hoffmann Sampaio ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
Electronic Devices ◽  
Preliminary Evidence ◽  
Composition Analysis ◽  
Base Metals ◽  
Circuit Boards ◽  
Physical Separation ◽  
Printed Circuit ◽  
Processing Circuit

Wastes from old electronic devices represent a significant part of the electronic scrap generated in developing countries, being commonly sold by collectors as low-value material to recycling hubs abroad. Upgrading the quality of this waste type could drive the revenue of recyclers, and thus, boost the recycling market. On this basis, this study investigated the possibility of concentrating metals from old wasted printed circuit boards through a physical separation-based route. Preparation of samples comprised fragmentation, size classification, density, and magnetic separation steps, followed by chemical and macro composition analysis. Cu, Al, Fe, and Sn constituted the major metals encountered in the scraps, including some peak concentrations of Zn, Sb, Pb, Ba, and Mn. Four distinct concentrate products could be obtained after suitable processing: (a) a light fraction composed of plastics and resins; (b) an aluminum concentrate; (c) a magnetic material concentrate, containing mainly iron; (d) a final concentrate containing more than 50% in mass of copper and enriched with nonferrous metals. Preliminary evidence showed that further processes, like the separation of copper wires through drumming, can potentially improve the effectiveness of the proposed processing circuit and should guide future works.

scholarly journals Survey of Solid Waste Management Status in Academic Centers: Case Study in a Military University

2018 ◽  
Vol 9 (2) ◽  
pp. 99-105
Author(s):  
Masoumbeigi Hossein ◽  
Safavi Seyed Abbas ◽  
Yousefi khoraem Mohammad ◽  
Mahmoudi Norouz
Keyword(s):  
Waste Management ◽  
Solid Waste ◽  
Solid Waste Management ◽  
Average Weight ◽  
Physical Analysis ◽  
Cross Sectional ◽  
The Status ◽  
Characterization Studies

Background: Planning and optimum waste management as the first step has need to waste characterization studies including the existing status, quantity and quality (physical composition) of generated solid waste at University. The aim of this study was evaluation of the existing situation, identification of the quantity and quality of solid waste in one of Iranian military universities. Materials and methods: This cross-sectional research was done in one of the Iranian military universities. The status of waste management was determined using self-made checklist (valid and reliable) and site visits and documents analysis. Quantity, quality, and physical analysis of waste was determined by weighting via trained personnel. The collected data were analyzed using SPSS 18 software and descriptive statistical methods. Results: Existing situation of waste management which has 58 score was weak in comparison with desirable situation as 112 score. The average weight, capitation and density of the waste were 419 kg/d, 288 gpc/d and 105.3 kg/m3 respectively. Putrescible waste 40.15%, paper and cardboard 13.99%, soft plastics 13.10%, dried plastics 6.35%, wood and plant waste 6.14%, glass 5.64% and ferrous metals 0.82% were the predominant components. Conclusion: Despite separation of valuable dry wastes, waste management status in this university is not desirable. . 40% of total wastes were valuable and recyclable. Recycle is a best-recommended procedure, which can lead to volume and capitation reduction and decreasing of collection, transport and disposal costs nearly 50%.  

Effect of Dolomite on Pyrolysis of Rice Straw

2013 ◽  
Vol 795 ◽  
pp. 170-173 ◽  
Author(s):  
Razi Ahmad ◽  
Nasrul Hamidin ◽  
Umi Fazara Md Ali
Keyword(s):  
Rice Straw ◽  
Oxygen Content ◽  
Fixed Bed ◽  
Chemical Characterization ◽  
Product Yield ◽  
Fixed Bed Reactor ◽  
Bio Oil ◽  
Characterization Studies ◽  
Oil Characterization

A study of catalytic pyrolysis on rice straw was carried out in a fixed-bed reactor. The objectives were to determine the effect of dolomite catalyst on the distribution of product yield and bio-oil characterization. The non-catalytic and catalytic process of rice straw was performed at the optimum conditions. The chemical characterization studies of uncatalysed bio-oil derived from pyrolysis of rice straw reflect a considerable amount of carbonyl and oxygenated compound, resulting in higher oxygen content in elemental composition. In the presence of the dolomite catalyst, the yield of bio-oil was markedly reduced and so was the oxygen content of the bio-oil itself. The product yields and quality of the resultant bio-oil were significantly affected by the use of dolomite catalyst.

Research on Classified Magnetic Separation of Oolitic Hematite from Guizhou Province

2013 ◽  
Vol 634-638 ◽  
pp. 3433-3436
Author(s):  
Wen Hui Chen ◽  
Qin Zhang ◽  
Zhi Hui Shen ◽  
Mao Jiang
Keyword(s):  
Magnetic Separation ◽  
Size Fraction ◽  
Guizhou Province ◽  
Iron Recovery ◽  
Low Intensity ◽  
The World ◽  
Refractory Ores ◽  
Hematite Ore ◽  
Oolitic Hematite Ore

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%.

Germanium-On-Insulator (GeOI) structure realized by the Smart Cut™ technology

2004 ◽  
Vol 809 ◽  
Author(s):  
F. Letertre ◽  
C. Deguet ◽  
C. Richtarch ◽  
B. Faure ◽  
JM Hartmann ◽  
...  
Keyword(s):  
Cross Sections ◽  
Large Diameter ◽  
Bonding Layer ◽  
Detailed Characterization ◽  
Si Substrates ◽  
First Results ◽  
Defect Densities ◽  
Technological Options ◽  
Roughness Measurements

ABSTRACTFirst results on formation of thin film GeOI structures by the Smart Cut™ technology are presented in this paper. Thin single crystal layers of Ge have been successfully transferred, via oxide bonding layer, onto standard Si substrates with diameters ranging from 100 to 200 mm. Compared to SOI manufacturing, the development of GeOI requires adaptation to the available germanium material, since the starting material can be either bulk Ge or an epitaxial layer. Some results will be presented for GeOI formation according to the different technological options. Germanium splitting kinetics will be discussed and compared to already published results. To show good quality of the GeOI structures, detailed characterization has been done by TEM cross sections for defect densities, interfaces abruptness and layers homogeneities evaluation. AFM was used for surface roughness measurements. These results help define procedures that are required to achieve large diameter high quality GeOI structures.

scholarly journals On the Flotation of a Low Grade Chromite Ore

2012 ◽  
Vol 6 (1) ◽  
pp. 19
Author(s):  
Tamam T. A. K ◽  
Ahmed A.S.Seifelnasr
Keyword(s):  
Oleic Acid ◽  
Iron Oxides ◽  
Froth Flotation ◽  
Pulp Density ◽  
Operating Parameters ◽  
Low Grade ◽  
High Grade ◽  
Chromite Ore ◽  
Chromite Concentrate ◽  
Representative Samples

This study is concerned with the processing of low grade chromite ores, Ingassena Hills by froth flotation techniques. For this purpose, representative samples were taken from four different mines. Mineralogical examinations indicated that, the major minerals are chromite and serpentine .Olivine, iron oxides and talc have been identified as minor minerals. Adequate degree of liberation of chromite was obtained by grinding the ore to minus 177µm. Froth flotation was used to upgrade that particular chromite ore. Oleic acid was used as collector. Several operating parameters influencing the floatability of both high grade chromite and serpentine were investigated. These include the concentrations of the collector and depressant, pulp pH and conditioning time. From an ore feed grading 20.27% Cr2O3, a chromite concentrate of 28.71% Cr2O3 with recovery of 94.54 % could be obtained by flotation at collector dosage of 0.300 kg /t , neutral pulp (pH 9) ,conditioning time ,2min ,and pulp density, 20%.

scholarly journals Beneficiation of cassiterite from primary tin ores using gravity and magnetic separation

2021 ◽  
Vol 882 (1) ◽  
pp. 012008
Author(s):  
I Rodliyah ◽  
R Wijayanti ◽  
K N Hidayat ◽  
E A Dianawati ◽  
A Sudrajat ◽  
...  
Keyword(s):  
Magnetic Separation ◽  
Separation Method ◽  
Smelting Process ◽  
Ore Deposit ◽  
Physical Separation ◽  
Gravity And Magnetic

Abstract Alluvial tin ore deposit of PT. Timah is predicted to be depleted in the next 5 to 10 years. Finding a new source of tin ore is important for the company’s sustainability. PT. Timah has been exploring for primary tin ore. Tin (Sn) content in primary tin ore ranges from 0.2 – 1.0%. The Sn particles liberated in the cassiterite mineral are above 50% so they can be processed by the physical separation method. This research aims to observe the beneficiation of cassiterite from primary tin ore (oxide and skarn samples) using gravity and magnetic separation. The cassiterite concentrate produced from the beneficiation process is expected to be used as feed for the smelting process. Beneficiation results of primary tin ore (oxide and skarn samples) showed that cassiterite (SnO2) content were 15.09% and 40.03%, respectively and the recovery was 42.9% and 11.87%, respectively. The cassiterite concentrate produced from the beneficiation process cannot be used to feed the smelting process.

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