Magnetic Separation Technique Research Articles

Reprocessing of magnesite beneficiation waste to recover mineral value and minimise environmental footprint

The current paper deals with the re-processing of mineralised mine waste from magnesite processing operations aiming at the recovery of the value. Two cases of mineralised waste were examined. First, waste derived from the removal of “fine” before hand-sorting, with particle size of -40 mm; this waste is usually stockpiled, comprises mostly of relatively coarse particles and is of relatively high-grade in magnesite. The separation methods applied were sorting, sink-float tests and magnetic separation. In general, the results from the application of physical separation methods were satisfactory. Commercial concentrates were obtained from sorting with MgCO3-grade ranging between 94 and 97% MgCO3 and yield about 46%; in case of mixing concentrate with middling, yield rises to 58-64% while grade slightly drops to 91-94%. Equally satisfactory were the results from sink-float separation at sp.gr. 2.88 (grade 95%, yield 45%) but questions arise from the small sp.gr. difference of magnesite and gangues. Finally, the less satisfactory results obtained from magnetic separation (grade around 80-85%, yield 33-65%) may be due to inefficient particles liberation and higher magnetic field is maybe required. Second, mineralised waste consisting of fine particles from size reduction operations were tested. These fines were processed with selective magnetic coating as well as co-agglomeration / magnetic separation techniques. In general, the results of physicochemical processing of fines were very encouraging both on single minerals and their artificial mixtures. In case of magnetic coating, the effect of pH, collector concentration and kerosene dose was studied first on single minerals. Optimum results were obtained for pH=9, dodecylamine solution 4.5x10-5 M and kerosene 2.5 L/t. Tests on artificial mineral mixtures at optimum conditions and magnetic separation at 0.8 A resulted in non-magnetic product with MgCO3-grade higher than 99%. The parameters examined in co-agglomeration / magnetic separation tests were the same as with magnetic coating. Best conditions for co-agglomeration on single minerals were pH=8, dodecylamine 2 kg/t, kerosene 4 L/t. Tests on mineral mixture reveals that the MgCO3-grade increases with dodecylamine but the yield drops.

Magnetic separation of nickel-plating waste liquid using a high temperature superconducting bulk magnet

Ni is one of the important metal resources. Because Ni-containing waste liquid is drained after several plating turns in the factories, an effective recycling technique should be developed. A unique magnetic separation technique using high temperature superconducting bulk magnet has succeeded in collecting Ni-sulfate crystals, which were fabricated from the Ni-plating waste liquid. Pulsed-field magnetizing method was employed to activate the bulk magnet up to 2.80 T, which produced a field space of 1.40 T on the surface of the waste channel. Green coarse crystals were attracted from the flowing stream of Ni-saturated liquid containing weakly-magnetic particles of Ni-compounds. The magnetically-collected particles were identified as paramagnetic NiSO4/6H2O crystals, and slight differences in Ni concentration and grain size were observed between the particles attracted and not-attracted to the 1.8 T magnetic pole. In both cases, the large grains were found to consist of a single phase. The compound can be used as a raw material in the Ni-recycle process. This preferential extraction suggests a novel recycling method of Ni resource.

Effect of Xijiao Dihuang Combined Prescription on Human Dendritic Cell Function Induced by Lipopolysaccharide

To observe the effects of drug-containing serum of Xijiao Dihuang combined prescription(XJDH) on the related functions of dendritic cells(DCs) induced in vitro, and to explore the mechanisms underlying the effectiveness of XJDH treatment on primary immune thrombocytopenia(ITP). Peripheral blood samples were colle-ted from 6 healthy volunteers. Mononuclear cells were isolated by density gradient centrifugation, and CD14+ mononuclear cells were collected by the magnetic separation technique. CD14+ mononuclear cells were induced into immature DCs by recombinant human granulocyte-macrophage colony stimulating factor (GM-CSF) and recombinant human interleukin 4 (IL-4). Immature DCs were divided into three groups: control group, model group and XJDH group. CCK-8 assay was used to determine the intervention concentration and time of drug-containing serum. Lipopolysaccharide(LPS) with the final concentration of 1 μg/ml was added to model group and XJDH group respectively for 24 h to induce DCs maturation. Normal rat serum was added to control group and model group, and XJDH was added to XJDH group for 24 h. Flow cytometry was used to detect the levels of CD80, CD83 and HLA-DR on the surface of DCs. Western blot was used to detect the expression of TLR4 and NF-κB, and levels of IL-6, IL-12 and TNF-α in cell supernatant was detected by ELISA. Compared with the control group, LPS stimulation increased the expression of CD80, CD83 and HLA-DR, with subsequent increasing expression of TLR4 and NF-κB, as well as IL-6, IL-12 and TNF-α increased(P<0.05). In comparison with model group, the expression of DCs surface molecules CD80, CD83 and HLA-DR, DCs' expression of TLR4 and NF-κB protein, and the levels of IL-6, IL-12 and TNF-α in the cell supernatant of XJDH group decreased after the intervention of XJDH (P<0.05). Drug containing serum of Xijiao Dihuang combined prescription can down-regulate TLR4/NF-κB signaling pathway related protein expression, inhibit DCs maturation, and reduce proinflammatory factor secretion, which may be one of the mechanisms of drug-containing serum of Xijiao Dihuang combined prescription in the treatment of immune thrombocytopenia.

Mineralogical Studies and Radioactivity on Stream Sediments Around Wadi Aidib Area, South Eastern Desert, Egypt

Wadi Aidib lie at southern part of the Eastern Desert of Egypt, between 22° 15’ - 22° 21’ N and Longitudes 36° 20’ - 36° 30’ E, covering an area of about 30km2. It is covered by basement rocks dissected by several wadies, Wadi Aidib as a main wadi with several tributaries. Constant of channel maintenance showed the dissection of the studied basin by lineaments, fractures and joints, dissection is minimized in wadi Aidib. Landsat ETM+ false color composite image (bands 3, 2, 1) The rock types wide spread out at Wadi Aidib area contains metavolcanics, alkali feldspar granites, quartz diorites, biotite granites metasediments. Heavy liquid separation and magnetic separation techniques in addition to microscopic examination for the studied stream sediment samples were applied. The mineral resource tonnage for each concerned economic mineral 171.315 ilmenite; 93.150, magnetite; 25.110, zircon; 9.720, total rutile; 7.695, garnet; 1.215, monazite and 810.000 green silicates, in thousands of tons. The studied stream sediments are measured radiometrically using gamma-ray spectrometer for determination the radionuclides contents. U concentration varies between 1 and 2 ppm with 1.69 as an average, Th from 3 to 7 ppm with an average 4.92 ppm.

Beneficiation of Iron Oxides from Cupola Furnace Slags for Arsenic Removal from Mine Tailings Decant Water

Large volumes of ferrous metallurgical slags (FMS) are generated annually as waste materials from metal extraction, purification, casting and alloying processes worldwide. Some attempts have been made to use bulk FMS in metal precipitation and concrete works but little success has been achieved because of unstable precipitates and volume expansion of concrete structures. As a result, significant quantities of FMS are still disposed in landfills. This disposal leads to land conflicts and poor environmental practices. The present study focuses on the characterization and separation of iron oxide from selected bulk FMS (Cupola Furnace Slag - CFS) obtained from Ghana into constituent components for use as engineering materials. Quantitative X-ray diffractometry was used to determine the mineralogy of CFS. Iron oxide morphology and spot composition in the CFS were determined using scanning electron microscopy, combined with energy dispersive spectroscopy. The inductively coupled plasma-optical emission spectrometry was used to ascertain the chemical composition of CFS after acid digestion. Wet low intensity magnetic separation technique was employed for beneficiating iron oxides from the CFS. It is shown that the CFS is amorphous and consist of ferrous and non-ferrous material. Results of the investigation confirmed that ferrous materials in the slags can be separated using magnetic separation technique. The study further confirmed that fine grinding (- 75 µm) liberates the magnetic portions of the slag efficiently, and as such, they can be recovered using a low magnetic field. The recovery was 99.04 % and the concentrates obtained from the beneficiation process consist primarily of pigeonite, quartz, magnetite and jacobsite. The beneficiated concentrates have the capacity to adsorb arsenic from mine effluent. This study has demonstrated that, slags can be utilized as secondary resources rather than a waste.

An electrochemical aptasensor based on intelligent walking DNA nanomachine with cascade signal amplification powered by nuclease for Mucin 1 assay

Intelligently walking DNA nanomachines have sprung up an upsurge in various nucleic acid testing, but the rapid and sensitive test methods toward disease biomarker proteins based on the signal amplification strategy of DNA nanomachines were still ongoing development. In this work, an electrochemical aptasensor coupling the magnetic separation technique with the nuclease-powered walking DNA nanomachine was established for Mucin 1 (MUC1) detection. The magnetic beads (MBs) were modified by MUC1 aptamer hybridized with blocker DNA probe (BDP). After reacting with MUC1 proteins, the BDP was released from MBs to trigger the opening of capture hairpin DNA on Au nanoparticle (Au NPs)/MXene-modified electrode surface. In the presence of exonuclease III (Exo III), the BDP as a DNA walker is activated to autonomously move on the electrode. Then, lots of residual DNA fragments can still stay on electrode, further hybridizing with hairpin DNA, which can capture more UiO-66-NH2 metal-organic frameworks (MOFs). The amounts of ligands in MOFs can generate enhanced differential pulse voltammetry (DPV) signal probes. Furthermore, the concentrations of MUC1 can convert into the amplified DPV signals by introducing the signal amplification between the BDP as DNA walkers and Exo III as driven forces. This proposed electrochemical aptasensor achieved MUC1 detection ranging from 5 pg/mL to 50 ng/mL with detection limit of 0.72 pg/mL. Consequently, the designed and nuclease-powered walking DNA nanomachine provided an efficient strategy for the quantitative analysis of proteins by the interconversion between protein and BDP as a walker, which exhibited practical applicability of MUC1 detection in human serum.

Effect of Ultraviolet-C Light-Emitting Diode Treatment on Disinfection of Norovirus in Processing Water for Reuse of Brine Water.

Processes in the food industry that use large amounts of water have been an important cause of waterborne disease outbreaks, as they expose individuals to risks for waterborne disease transmission. Developing technologies to ensure the hygiene and safety of food-processing steps is an urgent concern from an economic perspective. Furthermore, economic benefits can be derived if the processed water can be reused under microbiologically safe conditions. Among the major manufacturing processes in the kimchi industry, the brining process for salted kimchi cabbages requires a considerable amount of brine (approximately 2,000–2,500 l/1,000 kg of raw cabbage). The aim of this study was to establish virucidal conditions with ultraviolet-C light-emitting diodes (UVC LEDs) that can ensure the microbiological safety of brine water samples with various turbidities for reuse after disinfection. For quantitative analysis, first of all, magnetic bead separation (MBS) technique was used to capture and recover the human norovirus (HuNoV) virus particles; propidium monoazide (PMA) combined with RT-qPCR (PMA-RT-qPCR) was subsequently used to selectively detect infectious norovirus. Overall, as the turbidity of the brine water samples increased, the reduction in the HuNoV genogroup II genotype 4 (HuNoV GII.4) levels by UVC LED disinfection decreased. The derived inactivation rate constant (kinac) and inactivation curves (calculated using the log-linear model) were studied as a function of turbidity based on the exponential one-phase inactivation kinetics of HuNoV. Using an impeller system set at 100 rotations/min (rpm) with an eight-nephelometric turbidity unit (NTU) sample (the lowest turbidity studied), the kinact based on the levels of viral genomic RNA concentrations was approximately 2.15-fold higher than that observed without rotation (0 rpm). Moreover, the kinact increased 1.69-fold with a 56-NTU sample (the highest turbidity studied) when the impeller system was set at 100 rpm. UVC LED treatment decreased the HuNoV GII.4 population more effectively in conjunction with the impeller system (100 rpm) than without the impeller system. Our novel findings and model provide fundamental and scientific data that may help reuse brine water and ensure its microbiological safety through disinfection. Our study highlights the benefits of UVC LED treatment in successfully eliminating waterborne viruses in a prompt, resistance-reducing, and energy-efficient approach at the laboratory scale, which lays the foundation for future plant-scale studies of UVC LED-disinfection systems.

Reverse Column Flotation of Ultrafine Magnetite Mixture with Fine Glass Beads Enhanced by Fine Bubbles

Magnetite ores are among the most important sources of iron, which is in high demand in the global economy. Metallurgical properties of the magnetite concentrate significantly depend on impurities of silicon- and aluminum-bearing minerals. These impurities have to be separated from ore by magnetic separation and flotation techniques. Reverse column flotation is one of the methods applied for reducing the content of impurities in magnetite concentrate. This method allows recovering impurities from ore in the froth product (flotation tailings). However, the efficiency of this method significantly decreases with the decrease in particle size. As previously demonstrated, the effectiveness of fine particle column flotation can be increased if, before feeding the pulp into a column, fine bubbles are introduced into the pulp and the pulp is then passed through a tubular reactor. The major purpose of this study was to define the effectiveness of the reverse column flotation performance of ultrafine magnetite from the mixture with fine glass beads (ballotini) when, before the pulp is fed into the flotation column, it is mixed with fine air-in-water dispersion, and the mixture is then passed through a tubular flotation reactor (TFR). The obtained experimental findings allowed the definition of the optimal conditions of the mixture treatment in TFR that ensured high concentrate grade and iron recovery for the initial iron content in the mixture of 63.76%. These conditions were defined as follows: treatment time of the mixture in the TFR—7.5 s; average flow shear rate inside the TFR—1000 s−1; volume dosage of fine bubbles per solid mass unit—0.032 or 0.21 mL/g. At the fine bubble dosage of 0.032 mL/g, the iron recovery and the concentrate grade were, respectively, 88.1% and 68.3% Fe, and at the dosage of 0.21 mL/g, the iron recovery reached 89.4% for the concentrate grade of 68.7% Fe.

MO404: Autophagy and Fibrotic Response is Genetically Determined in Mouse Mesangial Cells

Abstract BACKGROUND AND AIMS C57Bl6/J (B6) mouse strain is resistant to several experimental models of renal fibrosis. Mesangial cells play an important role in the pathogenesis of glomerulosclerosis. Also, autophagy dysregulation was recently related to fibrosis. However, it is unclear whether autophagy dysregulation could be genetically determined in mice. Thus, we investigated autophagy and fibrotic response in primary mesangial cells isolated from fibrosis resistant (B6) and fibrosis prone (CBA) inbred mouse strains. METHOD Primary mesangial cells were isolated from 6-weeks old B6 and CBA male mice via magnetic bead separation technique. Glomerular outgrowths were maintained in RPMI medium for 21 days when cells were subcultured and characterized for mesangial markers. Mesangial cells with passage numbers P5 to P8 were seeded onto 24-well plates. Gene expressions were analyzed after 48-h of PBS (CTL) or TGF-β (10 ng/mL) treatment (n = 6/group). Data (mean ± SD) were analyzed using Kruskal–Wallis test. RESULTS Tgfb1 and Col1a1 expressions increased by 2.5-fold and 8-fold in TGF-β treated CBA cells as compared to B6 (P &amp;lt; 0.01), respectively. The expression of Egr1 (early growth response factor-1) that participates in both fibrosis and autophagy increased by 2-fold in TGF-β treated CBA cells but remained unchanged in B6 cells (P &amp;lt; 0.05). Similarly, the expression of core autophagy molecule Lc3b did not change in TGF-β treated B6 cells, but increased by 60% in CBA cells (P &amp;lt; 0.05), accompanied by 1.5-fold increase of Sqstm1/p62. On the other hand, the expression of Mtmr14 that negatively regulates autophagy decreased by 30% in TGF-β treated CBA cells but remained unchanged in B6. CONCLUSION We conclude that genetic background of mice highly influences the TGF-β induced fibrotic and autophagy response of mesangial cells. Our results corroborate previous reports on autophagy dysregulation associated to fibrosis. FUNDING: Hungarian Academy of Sciences BO/00 304/20/5, ÚNKP-21–5-SE-1, NTP-NFTÖ-21-B-0045

A visual peroxidase mimicking aptasensor based on Pt nanoparticles-loaded on iron metal organic gel for fumonisin B1 analysis in corn meal

A visual colorimetric aptasensor combining platinum nanoparticles (Pt NPs) loaded on Fe-based metal organic gel (Fe-MOG) as peroxidase mimics with magnetic separation technique was designed for the detection of fumonisin B1 (FB1). Interestingly, based on the inherent properties of Fe-MOG such as porous nanostructures, abundant Fe2+/Fe3+ active metal centers and synergetic effect between Pt NPs and Fe-MOG, Pt NPs/Fe-MOG composites can be employed as excellent peroxidase mimetic enzyme to oxidize 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2. This process was accompanied by a color variation of the solution from colorless to blue. Kinetic analysis showed that the Pt NPs/Fe-MOG composites make an effective peroxidase mimic with low Michaelis constant (Km), high substrate binding affinity and rapid catalytic velocity (Vm). Furthermore, the Pt NPs/Fe-MOG based colorimetric aptasensor was used to detect FB1. The prepared Pt NPs/Fe-MOG achieved lower detection limit (2.7 pg/mL, 3σ/k) with a wide linear range of 0.01–2000.0 ng/mL. Finally, as a proof of concept of the rapidity and the simplicity of this colorimetric aptasensor, Pt NPs/Fe-MOG was used for the detection of FB1 in real corn samples.

Natural Radioactivity and Radiological Implications of Stream Sediments at Wadi Aidib Area, South Eastern Desert, Egypt

Wadi Aidib lies at the extreme southern part of the Eastern Desert, Egypt, between 22o15'- 22o21' N and Longitudes 36o20'-36o30' E. Landsat ETM+ false color composite image (bands 3, 2, 1) was used for regional discrimination for different rock types and provide an excellent base map for the study area, morphological features of the stream deposits of the study area were known from Landsat ETM images, in addition to several field observations. The studied stream sediments accumulate in the form of alluvial fans. They are mainly composed of sands, gravels, boulders and contain some heavy valuable minerals which are derived from metavolcanics, metasediments, quartz diorite, biotite and alkali feldspar granites. Heavy liquid separation and magnetic separation techniques in addition to microscopic examination for the studied stream sediment samples were applied to identify the heavy minerals in these sediments. These minerals are represented by magnetite, ilmenite, rutile, garnet, zircon, monazite and Green silicates. The distribution of some elements in the study area is clear that they are concentrated near the outcrops of granites. The radionuclide concentrations were measured in different stations using a calibrated gamma-ray portable detector (RS 230) and the heavy minerals causing radioactivity were separated by heavy liquids and determined by binuclear and environmental scanning electron microscopes. Uranium ranges between 5.25 and 32.05 ppm with an average of 16.63 ppm, Th between 4.4 and 17 ppm with 11.34 ppm as an average and potassium fall between 1.8 and 5.15% with an average of 3.4 %. Correlation between soil radioactivity and its mineralogical content indicate that the high radionuclides contents are mainly attributed to the presence monazite which is the principal source of both uranium and thorium. Uranium high concentrations could be related to the metamict zircon. Absorbed Dose Rate (D), annual effective dose equivalent radium equivalent activity, external and internal hazard index, in addition to activity gamma index caused by gamma emitting natural radionuclide are determined from the obtained values of 238U, 232Th and 40K. Fairly, some of the studied stations do not satisfy the universal standards. 40K plays the main and most important role in dose rate contribution.

Adhesion Promotes Allergic Rhinitis CD4+IL4+ T Cell Differentiation via ICAM1 and E-Selectin.

Neuroimmune communication plays an important role in allergic inflammation, but the neuroimmune regulation of allergic rhinitis remains unclear. The goal of this study was to investigate the role of CD4-positive T lymphocyte (CD4+ T cells) adhesion to D-U87 neuron-like cells in mediating allergic rhinitis CD4+ T cell differentiation. D-U87 neuron-like cells were derived from the human glioblastoma U87 cell line. CD4+ T cells were isolated from human peripheral blood using a magnetic separation technique. In vitro coculture of D-U87 neuron-like cells and CD4+ T cells was established. The number of adherent CD4+ T cells was counted using a fluorescence microscope. The percentages of CD4+IFNγ+ and CD4+IL4+ T cells and the levels of IFNγ and IL4 cytokines in the supernatant were measured by flow cytometry. The results showed that the number of adherent CD4+ T cells in patients with allergic rhinitis was significantly higher than that in healthy controls. In allergic rhinitis, the percentage of CD4+IL4+ T cells was significantly increased in the adherent group compared with that in the nonadherent group. Moreover, blocking ICAM1 and E-selectin decreased the number of adherent CD4+ T cells and the percentage of CD4+IL4+ T cells in allergic rhinitis. Adhesion contributes to CD4+IL4+ T cell differentiation in the in vitro coculture system of D-U87 neuron-like cells and allergic rhinitis CD4+ T cells, which may provide new insights into therapeutic strategies for allergic rhinitis.

Current Methods for Extraction and Concentration of Foodborne Bacteria with Glycan-Coated Magnetic Nanoparticles: A Review.

Rapid and accurate food pathogen detection is an essential step to preventing foodborne illnesses. Before detection, removal of bacteria from the food matrix and concentration to detectable levels are often essential steps. Although many reviews discuss rapid concentration methods for foodborne pathogens, the use of glycan-coated magnetic nanoparticles (MNPs) is often omitted. This review seeks to analyze the potential of this technique as a rapid and cost-effective solution for concentration of bacteria directly from foods. The primary focus is the mechanism of glycan-coated MNP binding, as well as its current applications in concentration of foodborne pathogens. First, a background on the synthesis, properties, and applications of MNPs is provided. Second, synthesis of glycan-coated particles and their theorized mechanism for bacterial adhesion is described. Existing research into extraction of bacteria directly from food matrices is also analyzed. Finally, glycan-coated MNPs are compared to the magnetic separation technique of immunomagnetic separation (IMS) in terms of cost, time, and other factors. At its current state, glycan-coated MNPs require more research to fully identify the mechanism, potential for optimization, and extraction capabilities directly in food matrices. However, current research indicates glycan-coated MNPs are an incredibly cost-effective method for rapid food pathogen extraction and concentration.

Red Mud as a Secondary Resource of Low-Grade Iron: A Global Perspective

Managing red mud (RM), a solid waste byproduct of the alumina recovery process, is a serious ecological and environmental issue. With ~150 million tons/year of RM being generated globally, nearly 4.6 billion tons of RM are presently stored in vast waste reserves. RM can be a valuable resource of metals, minor elements, and rare earth elements. The suitability of RM as a low-grade iron resource was assessed in this study. The utilization of RM as a material resource in several commercial, industrial operations was briefly reviewed. Key features of iron recovery techniques, such as magnetic separation, carbothermal reduction, smelting reduction, acid leaching, and hydrothermal techniques were presented. RMs from different parts of the globe including India, China, Greece, Italy, France, and Russia were examined for their iron recovery potential. Data on RM composition, iron recovery, techniques, and yields was presented. The composition range of RMs examined were: Fe2O3: 28.3–63.2 wt.%; Al2O3: 6.9–26.53 wt.%; SiO2: 2.3–22.0 wt.%; Na2O: 0.27–13.44 wt.%; CaO: 0.26–23.8 wt.%; Al2O3/SiO2: 0.3–4.6. Even with a high alumina content and high Al2O3/SiO2 ratios, it was possible to recover iron in all cases, showing the significant potential of RM as a secondary resource of low-grade iron.

Investigations of Metal Pollution in Road Dust of Steel Industrial Area and Application of Magnetic Separation

Pollution characteristics and ecological risks for metals in non-magnetic and magnetic road dust from steel industrial areas were investigated by applying a magnetic separation method. Metal (except for Al, Li, Ti, As, and Sb) concentrations in the magnetic road dust were 1.2 (Sn) to 7.8 (Fe) times higher than those in the non-magnetic road dust. For the magnetic road dust, the geo-accumulation index revealed a strongly to extremely polluted status for Cr, Zn, Cd, and Sb, a strongly polluted status for Mn, Cu, and Pb, and a moderately to strongly polluted status for Fe, Ni, Mo, and Hg. This result indicates that the dominant metal pollution sources of road dust in industrial areas were the traffic activities of heavy-duty vehicles. The mean content of magnetic particles accounted for 44.7% of the total road dust. The metal loadings in the magnetic road dust were 86% (Fe), 77% (Cr), 67% (Mn), 86% (Ni), 76% (Cu), 72% (Zn), 64% (Mo), and 62% (Cd), respectively. Removal of the magnetic fraction from road dust using magnetic separation techniques not only reduces metal contamination but can also improve effective road cleaning strategies or reduce waste generation.

Recovery of Cassiterite and Topaz Minerals from an Old Metallurgical Dump, Eastern Desert of Egypt

Huge amounts of tailing dumps as a result of mines’ blasting operations were impacting economic and environmental problems. Evaluation of one of these tailing dumps of the Eastern Desert of Egypt showed the presence of reasonable amount of cassiterite mineral reaching 0.199% SnO2. The mineral cassiterite was found as finely disseminated particulates, reached to 5 microns, within varieties of quartz-feldspar-hornblende-biotite granitic formations. In the present study, the processing regime considered from the beginning the alignment between reaching cassiterite mineral liberation size, and its extreme brittleness character. Stirring ball milling technique was applied to produce −0.51 mm product with minimum fines as possible, which was left aside for a separate study. The ground product −0.51 + 0.074 mm was subjected to joint shaking table/dry high intensity magnetic separation techniques after splitting it into two fractions, −0.51 + 0.21 mm and −0.21 + 0.074 mm. Each fraction was separately subjected to “Wilfley” shaking table. At optimum conditions, a shaking table concentrate was obtained with 0.29% SnO2 and an operational recovery reached 96.94% from a feeding contained 0.19% SnO2. The heavies and the two middling products after shaking table were directed separately after dryness to dry high intensity magnetic separation using “Eriez” rare earth roll separator, meanwhile the light fractions were rejected. Mathematically designed experiments were applied to optimize the separation process. At optimum conditions, a final cassiterite concentrate was obtained with 11.25% SnO2, and an operational recovery 94.08%. In addition, a topaz mineral concentrate was separated at splitter angle 65˚.

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

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.

Method of Microglial DNA-RNA Purification from a Single Brain of an Adult Mouse.

Microglia, the resident brain immune effectors cells, show dynamic activation level changes for most neuropsychiatric diseases, reflecting their complex regulatory function and potential as a therapeutic target. Emerging single-cell molecular biology studies are used to investigate the genetic modification of individual cells to better understand complex gene regulatory pathways. Although multiple protocols for microglia isolation from adult mice are available, it is always challenging to get sufficient purified microglia from a single brain for simultaneous DNA and RNA extraction for subsequent downstream analysis. Moreover, for data comparison between treated and untreated groups, standardized cell isolation techniques are essential to decrease variability. Here, we present a combined method of microglia isolation from a single adult mouse brain, using a magnetic bead-based column separation technique, and a column-based extraction of purified DNA-RNA from the isolated microglia for downstream application. Our current method provides step-by-step instructions accompanied by visual explanations of important steps for isolating DNA-RNA simultaneously from a highly purified microglia population.

Photocatalytic degradation of norfloxacin by magnetic molecularly imprinted polymers: influencing factors and mechanisms

ABSTRACT Novel magnetic molecularly imprinted polymers (MMIP) were prepared for selective removal of norfloxacin by effectively utilizing photocatalytic degradation and magnetic separation techniques. The imprinted material with titanium layer and multihole surface showed an excellent photocatalytic property. In this paper, the kinetics of photocatalytic degradation of norfloxacin by MMIP was explored, and the influences of environmental factors, including solution pH, humic acid, common ions and water media on photocatalytic performance of MMIP were elucidated. The results showed that MMIP had good adaptability and could degrade norfloxacin within 60 min, but the degradation rate constant decreased in surface water. Based on the identification of intermediate products, the possible degradation pathways of norfloxacin were analysed, speculating that it might be degraded into small molecules in the form of de-piperazine ring, de-carboxyl group and de-fluorine. Moreover, the mineralization ratio of norfloxacin could reach 84.2% after ultraviolet irradiation for 150 min, and the low cobalt release of MMIP enhanced the security of the material. The results of adsorption and degradation cycle tests showed that MMIP obtained by molecular imprinting technology had excellent performance in sustainable use for micro organic pollutants removal.

Two New Purification Methods of Hepatitis C Virus Particles from Serum-Free Culture System

Background: The traditional ultracentrifugation purification method of hepatitis C virus (HCV) particles requires special equipment, limiting its wide application. Therefore, more effective and convenient methods for HCV are needed. Objectives: The present study aimed to establish simple and effective purification methods for HCV. Methods: The infectious clone of the HCV genome (JFH-1) was transfected to the human hepatoma cell line (Huh7.5.1) and cultured in Dulbecco’s modified eagle medium/nutrient mixture F-12. The infectivity of JFH-1 culture was determined by reverse transcription-quantitative polymerase chain reaction and immunofluorescence. After concentration by centrifugal filter devices, HCV particles were purified by heparin-affinity chromatography and magnetic separation technique. The purified viruses were detected by the western blot and immune-electron microscopy. Results: The infectious titer of JFH-1 transfected Huh7.5.1 in the serum-free culture medium was 4.5 × 104 FFU/mL, and HCV ribonucleic acid load was 3.946 × 106 IU/mL in 30 days of cell culture post-transfection. After purification by heparin-affinity chromatography or magnetic separation method, viral particles were visualized with spherical morphology and an average diameter of 55 nm assessed by electron microscopy. The viruses were confirmed by the western blot and immune-electron microscopy with specific antibodies to HCV. Conclusions: The heparin-affinity chromatography and magnetic separation methods were established for the purification of HCV, which were simple and efficient methods for the stable purification of HCV particles on a large scale.