The other parameters were kept constant: pH value of feed solution was 2, initial Cr (VI) concentration was 111.674 mg/L, flow rate of Cr (VI) solution in magnetic separation chamber was 8 mm/min and temperature was 20 °C. The relationship of Cr (VI) dynamic E and T at different TBP concentration was shown in Fig. 12. Based on the …

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 …

Cr(VI) contamination has posed great threat to both the ecosystem and human health for its carcinogenic and mutagenic nature. A highly effective adsorbent for the removal of Cr(VI) was prepared and its adsorption mechanism was thoroughly discussed in this study. In detail, magnetic BiFeO3 and kenaf biochar were loaded on cross-linked …

During magnetic separation, they do not experience a magnetic attraction force. That is why diamagnetic materials are also known as non-magnetic; however, this is not strictly accurate. ... Singh, V., Ramamurthy, Y.: Improvement in Cr:Fe Ratio of Indian Chromite Ore for Ferro Chrome Production. Undefined (2012) Google Scholar Tripathy, …

Magnetic properties of AlCoFeNi and AlCo 0.5 Cr 0.5 FeNi HEAs (A) Magnetization (M) vs applied magnetic field (H) measured at a temperature of 300 K for AlCoFeNi and AlCo 0.5 Cr 0.5 FeNi HEAs.

The Cr:Fe ratio (chromium-to-iron mass ratio) of chromite affects the production of chrome-based ferroalloys. Although the literature contains numerous reports related to the magnetic separation of different minerals, limited work concerning the application of magnetic separation to fine chromite from the Sukinda region of India to …

The optimum grade that could be obtained from single-stage dry magnetic separation was 35.52% Mn, and with a Mn:Fe ratio of 1.77, and 44% Mn recovery in the case of sample 1; whereas, a 33.75% Mn grade, with a Mn:Fe ratio of 1.66 at Mn recovery of 44% was reported for Sample 2. It was observed that both samples had a similar input chemistry ...

A simple pilot-scale magnetic adsorption separation (MAS) device was designed, fabricated and tested in treating aqueous solution stream laden with highly toxic and mobile hexavalent chromium [Cr(VI)] ions using super-paramagnetic crystalline polypyrrole–magnetite nanocomposite (PPy–Fe 3 O 4 NC) as a mobile scavenger. In the …

An alkaline solution (0.1 M NaOH) favored the desorption of Cr (VI) from the magnetic biochar, and the removal of Cr (VI) still remained around 77.6% after four cycles of adsorption-desorption. The results showed that corncob derived magnetic biochar is a potentially efficient and recoverable adsorbent for remediation of heavy metals in water.

The contamination of chromium (Cr(VI)) in groundwater threatens public health because of the industrial development being historically less supervised. To remove Cr(VI) from groundwater and other surface waters, a new FeCl3-modified magnetic biochar (MBPH550) was prepared from a waste peanut hull. The magnetic potential was to …

The focus of this paper was a novel model of Cr(VI) extraction process. The original so-called "magnetic-fluids fixed bed" (MFFB), which bridged the solvent extraction and the fixed-bed extraction by the theory of the high gradient magnetic separation (HGMS), has been explained. The MFFB integrated …

In this work, a technique was proposed that involves direct reduction followed by magnetic separation for recovering Fe and Cr while removing Na from the extracted vanadium tailings. Thermodynamic analysis and process parameters such as the use of additives and the reduction temperature were experimentally determined. …

Phase separation in the AlCo(Cr)FeNi HEA ... It is therefore of interest for future studies of AlCo 0.5 Cr 0.5 FeNi magnetic HEAs to determine the effect of external magnetic field and/or stress annealing, kinetics, and other external stimuli on the formation of the precipitates and to achieve a control of magnetic anisotropy and magnetic ...

iScience Article Highly complex magnetic behavior resulting from hierarchical phase separation in AlCo(Cr)FeNi high-entropy alloys Qianqian Lan, 1,2 6 *Andra´s Kova´cs, Jan Caron, Hongchu Du, 1,3 Dongsheng Song, Sriswaroop Dasari,4 Bharat Gwalani,4 Varun Chaudhary, 5Raju V. Ramanujan, Rajarshi Banerjee,4,5 and Rafal E. Dunin-Borkowski1 …

Periyasamy et al. reported the synthesis of a magnetic cellulose-based adsorbent, which could achieve rapid solid–liquid separation in the magnetic field, but the Cr(VI) adsorption capacity (26.6 mg/g) and removal rate (53%) were relatively low (Periyasamy et al. 2017). However, the reported cellulose-based adsorbents were …

The magnetic separation efficiency of the grade of Cr and Fe in concentrate, concentrate yield, as well as the recovery rates of Cr and Fe were presented in Fig. 5 (d), which increased strikingly with the roasting time from 0.25 h to 1 h, and then changed little. As a result, 1 h was the suitable roasting time.

The overall recovery of the magnetic product is greater than 85%Fe (Dwari et al. 2013). 38 Magnetic separation of ferruginous chromite fines has been studied in a different magnetic separator (IRMS, RERMS, and WHIMS) and found that RERMS can upgrade the Cr: Fe ratio up to 2.6 with a lower yield of 13.9% as a non-magnetic product from a feed ...

Magnetic separation is a technology or process that exploits the difference in magnetic properties between the ore ... Further studies need to target recovery of these fine chromite using high intensity magnetic separation. Mg Si Al Cr Fe Ca . MMME 138-6 Acknowledgements The author is thankful for University of Johannesburg support, …

According to previously published research [36,37,38], chromium cannot be significantly reduced into metal at a temperature of 1373–1573 K, and the products obtained from magnetic separation contain almost no chromium; that is, (% Cr) a is very low and (% Cr) s is high, making L Cr in the magnetic separation process higher.

Magnetic switching of A2 gen-2 precipitates in the R1 phase in the AlCo(Cr)FeNi HEA. (a, b) Magnetic contribution to the phase shift ϕm recorded after returning to remanence from opposite out-of ...

@article{Muliwa2016MagneticAS, title={Magnetic adsorption separation (MAS) process: An alternative method of extracting Cr(VI) from aqueous solution using polypyrrole coated Fe3O4 nanocomposites}, author={Anthony M. Muliwa and Taile Yvonne Leswifi and Maurice Stephen Onyango and Arjun Maity}, journal={Separation and Purification …

Magnetic separation is a process where a contaminant is first attached onto a magnetic carrier material (e.g., magnetite), and subsequently, the contaminant-laden carrier is separated under a magnetic field. The simplest magnetic separator is a permanent magnet. ... The chemical compositions of the Aluchrom wire included Fe (70%), Cr ...

Magnetic separation was carried out with a magnetic separator, ... (% Cr) s is the chromium content in the tail slag after separation and (% Cr) a is the chromium content in the alloy after separation, both measured as wt.%. Because the purpose of this research was to enrich chromium in slag, the recovery rate of chromium was defined as …

More importantly, a relatively low pre-reduction temperature and selection of magnetic separation process were found to be more beneficial for chromium enrichment in slag; the highest chromium ...

To enhance the Cr:Fe ratio of the samples, gravity concentration by the spiral concentrator and magnetic separation by the wet-high intensity magnetic separator was used. The details of the experimental setup along with the process conditions are discussed in Section 2.3.1 and Section 2.3.2 .

ing separation method or magnetic separation method because of the magnetic difference between the metal and slag [19–22]. According to extensive experimental research and productive practices, the higher the ratio of chromium to iron (Cr/Fe) in slag, the higher the economic value of the slag. In reality, only when the mass ratio of …

Materials Engineering. Slag. Article PDF Available. Enrichment Characteristics of Cr in Chromium Slag after Pre-Reduction and Melting/Magnetic …

Magnetic separation has many advantages over traditional fixed-bed separation methods, such as activated carbon adsorption and affinity chromatography. ... Speciation studies confirmed Cr(VI) adsorption and redn. to Cr(III) by the PPy-PANI/Fe3O4 nanocomposite in solns. with initial pH of 2 and 3 and that no Cr(VI) redn. occurred at pH values of ...

2.4 High-Gradient Magnetic Separator (HGMS) As its name implies, a high gradient magnetic separator employs magnetic field charges to separate magnetic materials. …

2.4 High-Gradient Magnetic Separator (HGMS) As its name implies, a high gradient magnetic separator employs magnetic field charges to separate magnetic materials. Marston and Kolm introduced this method at the Massachusetts Institute of Technology in the late 1960s and early 1970s.