scholarly journals Beneficiation Of Chromium Waste By Means Of Magnetic And Gravitational Separation

2015 ◽  
Vol 60 (3) ◽  
pp. 1737-1744 ◽  
Author(s):  
M. Brożek ◽  
A. Surowiak ◽  
A. Jarosiński
Keyword(s):  
Shaking Table ◽  
Combined Method ◽  
Gravity Concentration ◽  
Sodium Dichromate ◽  
Physical Separation ◽  
Magnesium Compounds ◽  
Magnetic Analysis ◽  
Magnetic Product ◽  
Exact Separation ◽  
Optimum Separation

AbstractThe paper presents the results of investigations of chromium recovery from the Cr waste mud, originating in the production of sodium dichromate. The differentiation of physical properties of particles of different contents of chromium and magnesium compounds is a premise for the use of physical separation methods. The investigations were performed on 2 waste samples, taken by random from the waste dump. The investigations of magnetic and gravity concentration for sample I and II were made, respectively. The results of screen and float and sink analyses of sample II indicate that it is possible to obtain Cr- and Mg-enriched products by means of a combined method of separation, i.e. hydraulic classification and, next, gravitational concentration on the shaking table. The concept of gravity concentration of the tested chromium waste was verified in the technical scale on multiboard shaking tables. The advantage of these fittings in relation to laboratory conditions is the possibility of separation of discussed waste without previous classification. The longer time of separation on the industrial shaking table as well as the respective amount of water directed to the process together with feed enabled an exact separation of initial material. The obtained concentrate in such conditions contains from 25 to 35% Cr2O3, depending on the chromium content in the initial waste material. It results from the fractional magnetic analysis of sample I that by means of the magnetic separation it is possible to obtain the magnetic concentrate of Cr2O3content minimum 20% and, simultaneously, to obtain the non-magnetic product of increased MgO content. The optimum separation conditions regarding the yield and content of Cr2O3were determined. The highest value of criterionKfor the grade of the concentrate containing over 20% of Cr2O3is obtained when the 10 mm diameter balls and the 1150 kA/m magnetic field intensity are applied. The yield of the concentrate equals about 9.5 % and recovery of Cr2O3almost 22%. In the non-magnetic product the content of Cr2O3equals 7.74% and MgO 27.36%.

Experimental Studies on a Mineral Containing Titanium in Baoding Area

2013 ◽  
Vol 826 ◽  
pp. 34-37 ◽  
Author(s):  
Guo Zhen Liu ◽  
Shu Juan Dai ◽  
Li Mei Bai ◽  
Yu Xin Ma ◽  
Yong Zhang
Keyword(s):  
Magnetic Separation ◽  
High Intensity ◽  
Ph Value ◽  
Experimental Studies ◽  
Mineral Processing ◽  
Shaking Table ◽  
Gravity Concentration

The main elements can be recovered for mineral processing in a mineral containing titanium of Baoding area were Ti, Fe and V, and the elements in the main gangue minerals were Si and Al. Gravity concentration, gravity concentration-high intensity magnetic separation and gravity concentration-flotation tests were performed on the ore sample respectively. The results showed that, in the test of shaking table, when the grinding fineness was -0.074mm 93%, the productivity of concentrate can reach 32.24%; when grinding fineness was -0.074mm 93%, after gravity concentration-magnetic separation, 30.25% of concentrate productivity can be attained; when the grinding fineness was -0.074mm 85%, after gravity concentration-flotation, the productivity of concentrate was 3.31%. Maybe it's the condition of the tests wasn't controlled well, especially adjusting pH value in the flotation stage, it's hard to control, so the results were not very good.

scholarly journals Physical separation for upgradation of valuable minerals: a study on sands of the Someswari river

2015 ◽  
Vol 50 (1) ◽  
pp. 53-58 ◽  
Author(s):  
MA Rahman ◽  
MN Zaman ◽  
PK Biswas ◽  
S Sultana ◽  
PK Nandy
Keyword(s):  
Separation Method ◽  
Shaking Table ◽  
Heavy Minerals ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Magnetic Separator ◽  
Physical Separation ◽  
Iron Coating ◽  
Light Mineral ◽  
Plate Separator

The study is carried out to develop a physical separation method for upgradation of valuable minerals from sands of the Someswari River. Understanding the morphology and mineralogy of the heavy minerals may allow development of processing methods that produce the higher grade products. For this purpose, grain size analysis, microscopic, spectroscopic study and feasibility of physical separation by shaking table, electrostatic plate separator and induced roll magnetic separator have been done. Considering the huge quantity of sandy materials of the studied river sands and separation of heavy minerals magnetite, ilmenite and garnet from the bulk sands and further treatment of the light mineral quartz to remove iron coating could be use as glass-sands; either the light mineral quartz or heavy minerals will be the main product. From the overall study by physical separation method, the Someswari River is identified as potential resources for mineral processing.Bangladesh J. Sci. Ind. Res. 50(1), 53-58, 2015

scholarly journals Electrostatic Separation of Copper and Glass Particles in Pretreated Automobile Shredder Residue

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 879
Author(s):  
Beom-Uk Kim ◽  
Chul-Hyun Park
Keyword(s):  
Separation Efficiency ◽  
Separation Process ◽  
Electrostatic Separation ◽  
Physical Separation ◽  
Shredder Residue ◽  
Conductive Materials ◽  
Automobile Shredder Residue ◽  
Small Glass ◽  
Increasing Demand ◽  
Optimum Separation

There is increasing demand for an efficient technique for separating automobile shredder residue (ASR) obtained from end-of-life vehicles (ELVs). A particular challenge is the physical separation of conductive materials from glass. In this study, the performance of pretreatment and induction electrostatic separation process was evaluated. The results show that a sieving/washing (combination of sieving and washing) pretreatment was the most effective for removing conductive material compared to electrostatic separation alone. The optimum separation efficiency of copper products was achieved with an applied voltage of 20 kV, a relative humidity of less than 35%, and a splitter position of 8 cm. Although the separation efficiency was slightly reduced when some small glass particles remained attached to the conductive materials, the separation efficiency of copper from the pretreated ASR dramatically increased to 83.1% grade and 90.4% recovery, compared to that of raw ASR (34.3% grade and 58.6% recovery). Based on these results, it was demonstrated that the proposed sieving/washing pretreatment was proficient at removing conductive materials from glass; thus, it has the potential to significantly improve the efficiency of electrostatic separation for ASR.

Experimental Research of Low-Grade Tin-Iron Ore Separation

2013 ◽  
Vol 641-642 ◽  
pp. 377-380
Author(s):  
Yi Miao Nie ◽  
Qi Hui Dai ◽  
Xiao Long Lu
Keyword(s):  
Magnetic Separation ◽  
Concentration Ratio ◽  
Iron Ore ◽  
Shaking Table ◽  
Low Grade ◽  
Gravity Concentration ◽  
Iron Concentrate ◽  
Stage Separation ◽  
Concentrate Grade ◽  
Iron Grade

Iron ore and tin mineral are the mainly recovered minerals of the low-grade ore, which could be effectively separated by a strong magnetic separation-gravity concentration process, with ore iron grade of 20.3%, tin grade 0.18%. Stage grinding and stage separation was used, getting the grade of iron concentrate and the recovery rate of tin separation index, the feeder of tin was magnetic separation tailing, by shaking table re-election, obtained tin concentrate grade was 10%, production was 0.34% (compared to the original ore, tin dressing) .Tin concentration ratio reached more than 330.

A Combined Beneficiation Process to Recover Iron Minerals from a Finely Disseminated Low-Grade Iron Ore

2013 ◽  
Vol 634-638 ◽  
pp. 3273-3276
Author(s):  
Si Qing Liu ◽  
Min Zhang ◽  
Wan Ping Wang ◽  
Xiu Juan Li
Keyword(s):  
Magnetic Separation ◽  
Iron Ore ◽  
Shaking Table ◽  
Low Grade ◽  
Gravity Concentration ◽  
Iron Minerals ◽  
Iron Concentrate ◽  
Low Intensity ◽  
Mineralogical Study ◽  
Basic Facts

In this research, a refractory iron ore is processed, according to the basic facts of mineralogical study. Mineralogy shows that the ore is characterized by the finely disseminated iron minerals with a small amount in the ore. Iron minerals in the ore are mainly hematite and magnetite. On the basis of the ore characteristic, a flowsheet of "stage grinding-low intensity magnetic separation-high intensity magnetic separation-gravity concentration by fine shaking table" was developed. An iron concentrate assaying 51.45% Fe at a recovery of 62.12% was obtained when the raw ore contains 18.61% Fe.

Study on the Mineral Processing of Cassiterite from Flotation Tailings by a Combined Method

2014 ◽  
Vol 968 ◽  
pp. 185-189 ◽  
Author(s):  
Yi Qiang Liang ◽  
Sheng Jian ◽  
Cong Jie Zhu ◽  
Ji Bo Qiao
Keyword(s):  
Particle Size ◽  
Size Range ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Test Results ◽  
Combined Method ◽  
Gravity Concentration ◽  
Complex Composition ◽  
Flotation Process ◽  
Flotation Behavior

A tailings assaying 0.4% Sn is taken from a flotation process which is used to recover Cu, Pb and Zn. The cassiterite in the tailings is of fine dissemination and complex composition, which leads to difficulties to recover by traditional gravity concentration. In order to enhance the recovery of Sn and make good use of the tailings, particle size analysis and chemical analysis were conducted. Test results show that different flotation index under different size range can be obtained, and the flotation behavior of different size range was investigated. As a result, a reasonable process of gravity concentration and flotation after classification is proposed, which can enhance the Sn recovery remarkably.

scholarly journals A Process Mineralogical Evaluation of Chromite at the Nkomati Nickel Mine, Uitkomst Complex, South Africa

Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 709
Author(s):  
Thomas Dzvinamurungu ◽  
Derek Hugh Rose ◽  
Karel Stephanus Viljoen ◽  
Antoine Floribert Mulaba-Bafubiandi
Keyword(s):  
South Africa ◽  
Gravity Separation ◽  
Laboratory Scale ◽  
Shaking Table ◽  
High Grade ◽  
Gravity Concentration ◽  
Mineral Liberation ◽  
Mineralogical Study ◽  
Optimal Target ◽  
Ore Types

A process mineralogical study based on three texturally and mineralogically different chromite-bearing ore types at the Nkomati nickel mine was undertaken, with focus on chromite. Chromite is a by-product of the Ni-Cu-Co-PGE ore at Nkomati Nickel mine. These being the PCMZ_MG (medium-grade Ni-Cu sulphide silicate ore with disseminated chromite), PCMZ_HG (high-grade Ni-Cu sulphide silicate ore containing disseminated chromite) and MCHR (massive chromite unit) ore types. These were processed using benchtop flotation followed by gravity concentration using a shaking table at different grind sizes. Quantitative mineralogical data was obtained using a 600F Mineral Liberation Analyser for the unprocessed and processed ores at three selected target grinds. The Mineral Liberation Analyser data indicated that increased milling does not relate to increased chromite grades and recoveries, particularly for the disseminated PCMZ type ores based on laboratory-scale gravity concentration. The recovery is controlled largely by the chromite chemistry. The results also showed that the MCHR samples that underwent a pre-flotation stage before gravity separation had better Cr2O3 grades (45% to 47%) and recoveries (52% to 61%) than MCHR ore that did not undergo a pre-flotation stage, which recorded grades ranging from 44% to 46% and recoveries ranging from 43% to 60%. This holds promise for the blending of MCHR ores with the PCMZ ores. The PCMZ ores also displayed better Cr2O3 grades and recoveries at coarser grinds. The optimal target grind to process all three ore types is a P80 of 75 μm, which is the current grind size employed at Nkomati Nickel mine. Due to the low nickel price and grade the Nkomati Nickel mine is currently under care and maintenance.

Physical, Chemical, and Crystallographic Characterization of Anodic Coatings on High Strength Aluminum Base Alloys

1976 ◽  
Vol 34 ◽  
pp. 636-637
Author(s):  
R. E. Herfert ◽  
N. T. McDevitt
Keyword(s):  
Sulfuric Acid ◽  
Salt Spray ◽  
High Strength ◽  
Environmental Stability ◽  
Anodic Films ◽  
Sodium Dichromate ◽  
Corrosion Resistant ◽  
Aerospace Applications ◽  
Bond Strengths ◽  
Adhesive Bonded Joints

Durability of adhesive bonded joints in moisture and salt spray environments is essential to USAF aircraft. Structural bonding technology for aerospace applications has depended for many years on the preparation of aluminum surfaces by a sulfuric acid/sodium dichromate (FPL etch) treatment. Recently, specific thin film anodizing techniques, phosphoric acid, and chromic acid anodizing have been developed which not only provide good initial bond strengths but vastly improved environmental durability. These thin anodic films are in contrast to the commonly used thick anodic films such as the sulfuric acid or "hard" sulfuric acid anodic films which are highly corrosion resistant in themselves, but which do not provide good initial bond strengths, particularly in low temperature peel.The objective of this study was to determine the characteristics of anodic films on aluminum alloys that make them corrosion resistant. The chemical composition, physical morphology and structure, and mechanical properties of the thin oxide films were to be defined and correlated with the environmental stability of these surfaces in humidity and salt spray. It is anticipated that anodic film characteristics and corrosion resistance will vary with the anodizing processing conditions.

Improving soil remediation through characterization

1995 ◽  
Vol 53 ◽  
pp. 386-387
Author(s):  
E. C. Buck ◽  
N. L. Dietz ◽  
J. K. Bates
Keyword(s):  
Dust Particles ◽  
Radiochemical Analysis ◽  
Solid Product ◽  
Uranium Contamination ◽  
Physical Separation ◽  
X Ray ◽  
Rocky Flats ◽  
Remediation Strategies ◽  
Bearing Materials ◽  
X Ray Absorption

Operations at former weapons processing facilities in the U. S. have resulted in a large volume of radionuclidecontaminated soils and residues. In an effort to improve remediation strategies and meet environmental regulations, radionuclide-bearing particles in contaminant soils from Fernald in Ohio and the Rocky Flats Plant (RFP) in Colorado have been characterized by electron microscopy. The object of these studies was to determine the form of the contaminant radionuclide, so that it properties could be established [1]. Physical separation and radiochemical analysis determined that uranium contamination at Fernald was not present exclusively in any one size/density fraction [2]. The uranium-contamination resulted from aqueous and solid product spills, air-borne dust particles, and from the operation of an incinerator on site. At RFP the contamination was from the incineration of Pu-bearing materials. Further analysis by x-ray absorption spectroscopy indicated that the majority of the uranium was in the 6+ oxidation state [3].

Combined Method for Treating Severe Recurrent Post Burn Flexion Contracture of the Knee Joint: Free Flap and Ilizarov Apparatus

2006 ◽  
Vol 22 (04) ◽  
Author(s):  
Batia Yaffe ◽  
Eyal Winkler ◽  
Nir Scher ◽  
Michael Berenstein ◽  
Amos Schindler
Keyword(s):  
Knee Joint ◽  
Free Flap ◽  
Flexion Contracture ◽  
Combined Method ◽  
Ilizarov Apparatus
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