Laser Diffraction Particle Size Analyzer Research Articles

Cyclic reduction of combusted iron powder: A study on the material properties and conversion reaction in the iron fuel cycle

Recently, iron powder has been proposed as a high energy density, easily storable, and CO2-free energy carrier. During the iron combustion, thermal energy is released as heat. The combusted products, the iron oxide particles, are captured and cyclically reduced back into iron powder in a process that is powered by renewable energy. Each combustion step, followed by a reduction, constitutes one cycle in the process. Previous studies predominantly focused on the reduction and combustion as individual steps. This work investigates the impact of cyclic combustion-reduction on material properties, with the specific focus on the reduction of iron oxides using hydrogen under fluidisation conditions. The powder is combusted and reduced for 3 cycles under the same conditions. Afterwards the properties of the powder and the reaction conversion are characterized. The physical techniques used for size and shape analysis include laser diffraction particle size analysis and scanning electron microscopy (SEM). For structure and chemistry, X-ray diffraction (XRD) and energy dispersive X-ray (EDX) analysis are also employed. To study the effect of the reduction conditions on the cycle and on the material properties of the powder, different experiments are conducted using 550 and 575°C as reduction temperatures. The higher conversion is observed at 575°C. During the first combustion particles resulted in large agglomerates and required a manual grinding step before being sent to the next reduction. However, the particle size distribution remains relatively stable in all subsequent cycles. The results suggest that the powder can be effectively utilized in the iron fuel cycle without requiring additional intermediate treatments, such as grinding and sieving after each cycle. This aspect highlights the potential feasibility and simplicity of implementing the cyclic combustion-reduction process for practical applications of iron powder as an energy carrier.

Degradation of tannic acid using monopersulfate activated CuO particles

A Copper(II) oxide material was synthesized and its efficiency in degrading Tannic acid (TA) was investigated using ultraviolet (UV) irradiation and CuO activated peroxymonosulfate (PMS). The CuO particle catalyst exhibited exceptional activity and was characterized using XRD, SEM, Raman spectroscopy, and laser diffraction particle size analysis (LDPS). The influence of calcination temperature, UV power, PMS dosage, CuO dosage, and coexisting anions on the degradation rate of TA was examined. The research results demonstrate that the addition of a structural guide enhances the catalytic performance of CuO. Among the different calcination temperatures investigated, CuO calcined at 500 °C demonstrates the best catalytic performance and achieves the highest degradation efficiency under neutral conditions. Under the optimal conditions of 0.1 g/L CuO and 1.2 mmol/L PMS, the TA degradation rate of 15 mg/L within 40 min was 97.69%, and the total organic carbon removal rate was 69.85%. Quenching experiments confirmed the participation of multiple active species in the decomposition process. After five experimental cycles, the CuO material maintained a TA removal rate above 92%. Furthermore, HPLC-MS analysis was employed to identify potential intermediates in the degradation of TA.

Deformation Characteristics of Combined Heavy Metals-Contaminated Soil Treated with nZVI through the Modified Slurry Consolidation Method

Nanoscale zero-valent iron (nZVI) has been widely applied to remediate heavy metal-contaminated soils and water. Its in situ treatment of combined heavy metal contaminated soil, followed by backfilling or other sustainable reutilizations, attracted attention to the treated soil’s deformation characteristics. In this study, soil samples were prepared using the modified slurry consolidation method to simulate the natural settling of backfilled soil and optimize the reactivity between nZVI and contaminants in soil. The deformation characteristics of natural soil, contaminated soil, and soil treated with varying dosages of nZVI (0.2%, 0.5%, 1%, 2%, and 5%) were investigated. Moreover, the plasticity indexes and particle-size distribution of the samples were examined through Atterberg limits and laser-diffraction particle-size analysis. After a 4 d slurry consolidation process, a typical result indicated the immobilization efficiency of all three heavy metal ions achieved over 90% with 2% nZVI. The presence of three heavy metal ions decreased the Atterberg limits and increased the compression index, permeability, and consolidation coefficient of the soil. Conversely, the introduction of nZVI increased plasticity and resulted in higher permeability, stable secondary consolidation, and less swell. Microscopically, with an increase in the dosage of nZVI, the soil aggregates transformed from a weak chemical bond with insoluble precipitates/iron oxides to larger aggregates consisting of nZVI/-soil aggregates, thereby enhancing the soil skeleton. This study shows improved permeability and deformation characteristics in nZVI-treated combined heavy metal-contaminated soil, offering valuable insights for practical nanomaterials’ in-situ treatment in engineering applications.

Characterization of spray dried cellulose nanofibrils produced by a disk refining process at different fineness levels

Three types of wood pulp feedstocks including bleached softwood kraft, unbleached softwood kraft and old corrugated containers were disk refined to produce cellulose nanofibrils at different fineness levels ranging from 50 to 100%, and the resulting aqueous suspensions of cellulose nanofibrils were spray dried. The spray drying experiments were carried out to examine different processing conditions for the different CNF feedstock types and fines level at various suspension concentrations to produce dry samples with free-flowing powder morphologies. The fineness levels and solids contents of CNF suspensions were set to 80% or more and 1.8% or less, respectively. If the solids content of the CNF solutions was high and the fibrillation level was low, plugging was experienced in the spray head because of the high viscosity of the suspensions, resulting in production of poor-quality powders. In terms of reduction in processing energy, even if the CNF suspension solids content was increased to 1.5 wt.%, the powder quality and the production yields were excellent. It was confirmed that high-quality powder under 20 µm were produced at a 90% fibrillation level of all CNF feedstocks. The resulting dry CNF powders were characterized to determine particle size distributions and morphological properties via a scanning electron microscope and a laser diffraction particle size analyzer. The particle sizes were smaller at higher fibrillation levels and lower solids content of the CNF suspensions. The CNF suspension derived from bleached kraft pulp, the average particle size decreased by 43% and 33% with the lowered solids contents from 1.8 to 1%, and the increased fineness levels from 80 to 100%, respectively.

Fabrication and characterization of coated ceramic membranes from natural sources for water treatment applications

This study aimed to fabricate ceramic membranes for water treatment applications using natural and cost-effective materials. This is the first-time white clay, Arabic gum, and marble powder were used in ceramic membranes. Two ceramic membranes were fabricated using an extrusion process: substrate A and substrate B. The JMP software (Version 15) was used to obtain the optimal recipes for the two substrates, which were white clay (62.7 %), silica flour (32.3 %), and Arabic gum (5 %) for substrate A and white clay (63 %), silica flour (26.8 %), and marble powder (10.2 %) for substrate B. Additionally, the effect of waste glass in the coating layer on the separation rate was examined. The ceramic membranes were analysed using various techniques, including X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), laser diffraction particle size analysis, thermogravimetric analysis (TGA), and a universal testing machine. The morphologies of the membranes were observed using scan electron microscopy (SEM), and their chemical resistances were evaluated. The flux across the substrates was measured using a crossflow filtration system, and it was found that substrate B had a higher flux (116 L/m2h) than substrate A (77 L/m2h). This was probably due to its higher porosity (34 %) compared to substrate A (29 %). Substrate A, with a coating layer (CO-2), exhibited the highest removal efficiency of approximately 99.2 % for synthetic feed water composed of tap water and bentonite clay, with an average particle size of 1.1 μm and turbidity of 13 ± 0.2 NTU. The costs of ceramic membranes A and B were estimated to be approximately 51 and 47 USD/m2, respectively. Their cost-effectiveness results from the use of low-cost materials that do not require high sintering temperatures. This study demonstrates that these ceramic membranes are not only affordable but also possess desirable properties for water treatment applications.

Experimental study on the mechanical properties and cementation mechanism of microbial cemented fine tailings backfill

The extensive exploitation of metal mines has resulted in the generation of vast quantities of fine tailings, posing significant environmental challenges such as surface subsidence and deposition. The conventional cemented backfill technology, which has been widely used for tailings processing, requires substantial cement consumption and thus leads to escalated economic costs and carbon emissions. In this paper, we propose a pollution-free alternative, Microbial-Induced Calcite Precipitation (MICP) technology, as a promising solution for sustainable mine filling. The study employs microscopic and macroscopic analysis techniques, including laser diffraction particle size (LDPS) analysis, scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), to investigate the inner structure and mechanical properties of the microbial cemented fine tailing backfill (MCFB). Key parameters such as unconfined compressive strength (UCS), CaCO3 content and porosity are examined, with a focus on the effects of bacterial solution dosage and curing time. The results reveal that the MICP-processed fine tailings exhibit an increase in particle size by approximately 292.1% compared to their original size. Furthermore, MCFB specimens demonstrates significantly enhanced UCS and decreasing porosity under comparable conditions, surpassing the performance of traditional cemented fine tailings backfill (CFB) specimens. Microscopic analysis highlights that the strength development in MCFB predominantly arises from the cementation effects of MICP-induced CaCO3, primarily in the form of calcite, rather than the cementation effects resulting from hydration products (C-S-H) in conventional CFB.

Selective recovery of vanadium from high-chromium vanadium slag by a mechanically activated low-sodium salt roasting-water leaching process

Stabilizing the toxic element chromium and improving vanadium recovery are crucial for the economic and efficient treatment of high chromium-bearing vanadium slag. This study employed mechanical activation to enhance vanadium extraction from high chromium-bearing vanadium slag through a low-sodium salt roasting-water leaching process. The effects of Na2CO3 addition, roasting temperature, and roasting time were investigated to determine the optimal roasting parameters. Subsequently, the effects of mechanical activation on the morphological and microstructural changes were characterized using a laser diffraction particle size analyzer, a micropore physisorption analyzer, scanning electron microscopy, energy dispersive spectrometry, and X-ray diffraction. The effects of mechanical activation on the extraction of vanadium and chromium were determined by leaching the roasted samples after varying activation times. The results indicated that mechanical activation decreased particle size, increased surface area, and enhanced the activity of the samples. The leaching results demonstrated that mechanical activation enhanced the leaching efficiency of vanadium by 5 %, reduced the optimum roasting temperature by 50 ℃, and slightly increased the leaching efficiency of chromium by 0.5–1 %.

Image-based simultaneous particle size distribution and concentration measurement of powder blend components with deep learning and machine vision

This work presents a system, where deep learning was used on images captured with a digital camera to simultaneously determine the API concentration and the particle size distribution (PSD) of two components of a powder blend. The blend consisted of acetylsalicylic acid (ASA) and calcium hydrogen phosphate (CHP), and the predicted API concentration was found corresponding with the HPLC measurements. The PSDs determined with the method corresponded with those measured with laser diffraction particle size analysis. This novel method provides fast and simple measurements and could be suitable for detecting segregation in the powder. By examining the powders discharged from a batch blender, the API concentrations at the top and bottom of the container could be measured, yielding information about the adequacy of the blending and improving the quality control of the manufacturing process.

Nanoencapsulation of α-mangostin using chitosan-oleic acid complexes: Evaluation of storage stability, in vitro release properties in simulated digestive environment, and bioaccessibility

The mangosteen fruit possesses a potent antioxidant known as α-mangostin. However, the poor aqueous solubility of α-mangostin limits its incorporation into food products, as well as its oral bioaccessibility in the human gastrointestinal tract. Therefore, we utilized electrostatic complexation between chitosan and oleic acid to encapsulate α-mangostin as a strategy to overcome these limitations. As a result, a homogeneous nanoparticle suspension (average particle diameter = 830 nm) was achieved, as verified by scanning transmission electron microscopy and laser diffraction particle size analysis. Importantly, the aqueous solubility of α-mangostin was significantly improved (>800 times), as examined using high-performance liquid chromatography, enabling its effective incorporation into foods and beverages. The nanoparticles were stable and conveniently stored in a dark vial at 4 °C for more than 2 weeks. In the simulated gastric environment, the pH sensitivity of the chitosan-oleic acid complexes enabled the α-mangostin to remain encapsulated in the gastric phase (pH 3) and to be released in the intestinal phase (pH 7) with a bioaccessibility percentage greater than 50%. Overall, the novel synthesized α-mangostin-encapsulated nanoparticles are beneficial for the design of functional foods with enhanced quality, gastrointestinal stability, and delivery.

Toward a tunable fabrication of multifunctional iron-aluminum spinels via solution combustion synthesis: The effects of fuel, heating mode, and Fe:Al precursor ratio

The solid solutions of iron and aluminum spinels (hercynite, maghemite, magnetite, and γ-alumina) are promising materials for emerging technologies such as solar thermochemical fuel production and clean dehydrogenation of fossil fuels. Solution combustion synthesis (SCS) is an attractive technique for the fabrication of these materials as it has been used for synthesis of many nanoscale oxides. However, the design space of SCS is large with many synthesis parameters affecting the properties of the combustion products. To optimize the SCS of these materials, it is important to determine which parameters yield the best properties. In the present work, FeAlOx nanocomposites were obtained by SCS using iron nitrate and aluminum nitrate as precursors and oxidizers. Two fuels (citric acid and glycine), three Fe:Al molar ratios (1:2, 1:1, and 2:1) in the precursors, and three heating modes (hotplate, muffle furnace, and microwave oven) were compared. The products were characterized by X-ray diffraction analysis, scanning electron microscopy, Brunauer-Emmett-Teller surface area analysis, and laser diffraction particle size analysis. The fuel used had the largest impact on the combustion behavior and hence the material properties. The high combustion temperature of glycine allowed for the formation of an FeAl2O4/Fe3O4 solid solution, while the lower-temperature combustion of citric acid yielded Al-substituted γ-Fe2O3 with high amorphous content. With citric acid, the specific surface area as high as 200 m2/g was achieved. The effect of Fe:Al precursor ratio was clearly seen in variations of the lattice parameter, which demonstrated the ability to tune the phase composition. The heating mode had minor effects on material properties, but some differences were observed. All products obtained by SCS in a microwave oven had low specific surface areas compared to those obtained with a hotplate and a muffle furnace.

Engineering artesunate-loaded micelles using spray drying for pulmonary drug delivery

Novel d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) micelles containing the anti-cancer drug artesunate (ART) were developed in a dry powder form for inhalation for the treatment of lung cancer. Targeted delivery to the lungs via inhalation is a challenge and the current study involved the development, characterization, and cytotoxicity determination of the dry powder formulations. TPGS micelles encapsulating ART were successfully prepared using thin-film hydration method followed by the preparation of dry powder formulation by spray-drying that included lactose and leucine as carrier molecules. Characterization of the dry powder formulation using Sympatec laser diffraction particle size analyzer and next generation impactor showed a unimodal particle size distribution with a mean particle size of 3.27 μm and a fine particle fraction of 31%, respectively. Artesunate loaded micelle dry powder formulation demonstrated higher cytotoxicity towards the A549 adenocarcinomic human alveolar basal epithelial cell line when compared to currently used cancer therapies docetaxel and doxorubicin. In general, this study demonstrates that spray-dried micelles containing artesunate can potentially be used as a dry powder formulation for inhalation for the treatment of lung cancer.

Transforming spent coffee grounds into a valuable resource for the enhancement of concrete strength

The decomposition of organic waste going to landfills produces methane gas, which is 21 times worse than CO2 in its global warming potential. Spent coffee grounds (SCG) are one type of organic waste that makes up a significant proportion of the organic waste going to landfills. Therefore, it becomes imperative to look for a recycling solution to transform this waste into a valuable resource. The concrete industry has the potential to contribute significantly to increasing the recycling rate of this waste material. However, due to its high organic content, it is unsuitable to be used directly in structural concrete. Therefore, this experimental project looks at pyrolysing this waste at different temperatures (350 and 500 °C) to identify its suitability in improving the physicochemical and mechanical properties of concrete. The raw and pyrolysed forms of SCG were used as a replacement of fine aggregates (FA; sand) at 5, 10, 15 and 20% volume replacement levels. X-ray fluorescence (XRF), Carbon, Hydrogen, Nitrogen, and Sulfur (CHNS) analysis, laser diffraction particle size analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM) and compressive strength tests were undertaken to investigate the properties of the raw material and their performance in the blended concrete composites. The results show that the leaching of organic compounds from the SCG hinders the hydration reaction of cement particles, thereby significantly hampering the compressive strength of SCG-blended concrete. However, pyrolysing the SCG at 350 °C led to a significant improvement in its material properties, which resulted in a 29.3% enhancement in the compressive strength of the composite concrete blended with coffee biochar.

Stability and Activity of Interferon Beta to Treat Idiopathic Pulmonary Fibrosis with Different Nebulizer Technologies.

Background: Idiopathic pulmonary fibrosis (IPF) is a serious lung disease characterized by lung scarring, which results in breathing difficulty. Currently, patients with IPF exhibit a poor survival rate and have access to very limited therapeutic options. Interferon beta (IFN-β) has been approved by the U.S. Food and Drug Administration (FDA) for the treatment of relapsing forms of multiple sclerosis, and it has also been shown to exhibit therapeutic potential in IPF. However, clinical use of IFN-β did not lead to improved overall survival in IPF patients in existing studies. One possibility is the limited efficiency of IFN-β delivery through intravenous or subcutaneous injection. Materials and Methods: The aerosol particle size distribution was determined with a laser diffraction particle size analyzer to characterize the droplet size and fine particle fraction generated by three types of nebulizers: jet, ultrasonic, and mesh. A breathing simulator was used to assess the delivery efficiency of IFN-β, and the temperature in the medication reservoirs was monitored with a thermocouple during nebulization. To further evaluate the antifibrotic activity of IFN-β pre- and postnebulization, bleomycin (BLM)- or transforming growth factor-beta (TGF-β)-treated human lung fibroblast (HLF) cells were used. Cell viability was measured by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Transwell migration assay and Q-PCR analysis were used to evaluate cell migration and the myofibroblast differentiation ability, respectively. IFN-β protein samples were prepared using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) sample loading buffer, and the expression of IFN-β was assessed by western blotting. Results: Among the current drug delivery systems, aerosolized medication has shown increased efficacy of drug delivery for treating respiratory diseases when compared with parenteral drugs. It was found that neither the structural integrity nor the biological function of nebulized IFN-β was compromised by the nebulization process of the mesh nebulizer. In addition, in BLM dose-response or TGF-β-induced lung fibroblast proliferation assays, these effects could be reversed by both parenteral and inhaled IFN-β nebulized with the mesh nebulizer. Nebulized IFN-β with the mesh nebulizer also significantly inhibited the migration and myofibroblast differentiation ability of TGF-β-treated HLF cells. Conclusions: The investigations revealed the potential efficacy of IFN-β in the treatment of IPF with the mesh nebulizer, demonstrating the higher efficiency of IFN-β delivered through the mesh nebulizer.

Recommendations for soil sample preparation, pretreatment, and data conversion for texture classification in laser diffraction particle size analysis

With regard to the differences between soil particle size distribution (PSD) obtained by sieve-sedimentation methods (SSMs), e.g., the sieve-pipette method (SPM) and the laser diffraction method (LDM), usually, the clay fraction content in LDM measurements is lower than in SSM. Two groups of reasons can be identified for this. Firstly, differences resulting from the features of the methods themselves. Secondly, differences resulting from the soil sample preparation (after sampling) and pretreatment (disaggregation). These differences not only cause difficulties in the PSDs comparability but also make it difficult, and sometimes even impossible, to apply the LDM results to soil texture classification. The solution to this difficulty may be to use pedotransfer functions and standardization of measurement procedures. The aim of this work was to validate the pedotransfer function proposed by Makó et al. (2017) on a Polish soil physics database for recalculating the results from LDM to compare them with SPM results and assess how the soil preparation and pretreatment influenced the obtained PSD and resulting soil texture classification. Using the pedotransfer function, 74 % accuracy was achieved, which is comparable with the results of other pedotransfer functions reported in the literature. Comparing the PSD results for the methods of sample preparation found in the literature after sampling (analysis of fresh, air dry and oven-dried – in 105 °C – soil) and pretreatment before the measurement (breaking soil aggregates chemically and physically) allows recommending the conducting of LDM PSD measurements using air dry soils and soil ultrasound disaggregation.

Studi pengaruh penggilingan kondisi kering dan basah terhadap kinetika dan karakteristik distribusi ukuran butir bijih sulfida kompleks galena sfalerit – Uji pendahuluan

Grinding is generally carried out in wet conditions, but issues regarding water conservation and high-water treatment costs encourage the application of grinding in dry conditions. Both produce products with certain characteristics that affect the success of the next process. Grinding of P100 6 mesh (3.36 mm) ore was performed using steel ball media with dry and wet grinding with 33.33% solids for 5, 10, 15, 20, 25, and 30 minutes. Particle size distribution of the grinding product was obtained from the wet sieving process and the -200 mesh (-75µm) ore particles were analyzed using a laser diffraction particle size analyzer. The Alyavdin grinding kinetics equation model was used to study the kinetics of ore grinding behavior and the particle size distribution and its characteristics consisting of uniformity index, size modulus and fractal dimension were studied using the logistic, Rosin-Rammler (RR) and Gates-Gaudin-Schuhmann (GGS) equation model. Equivalent particle size (EPS) and specific surface area (SSA) observations were carried out on the -200 mesh (-75µm) grinding product. Grinding in dry condition is more effective in reducing the size of complex galena-sphalerite sulphide ore, indicated by high grinding rate with the highest K value of 0,135/minute, high cummulative % undersize, low size modulus, high uniformity index, high fine particle and high SSA compared to wet grinding. Alyavdin's kinetics model can describe the grinding kinetics of galena sphalerite complex sulfide ore, while the particle size distribution follows the logistic equation model.

Study of Microstructural and Mechanical Properties of Ti-Alloys Synthesis from High Energy Ball Milling by Spark Plasma Sintering - A Review

Titanium and its alloys are attractive engineering materials used in aerospace, automotive, biomedical, and marine industry because of their outstanding mechanical properties such as high specific strength and physical properties with excellent corrosion resistance and excellent elevated temperature properties. This paper presents a brief review on the The effects of ball-milling time on the microstructure and mechanical properties of the ball-milled powder and sintered compact were investigated. As-milled powders and sintered Ti-Alloys samples were evaluated by X-ray diffraction, scanning electron microscopy, energy dispersive spectrometry, laser diffraction particle size analysis, and transmission electron microscopy.

The influence of particle size distribution on the curing behavior of ceramic-filled resins for vat photopolymerization

Optimizing the process of vat photopolymerization for ceramics necessitates the thorough understanding of the complex interactions between light and ceramic particles. However, it is not yet fully described how the size distribution of ceramic particles affects the curing behavior of ceramic-filled resins. Thus, this contribution provides insight into the influence of the particle size distribution (PSD) on the rheological behavior and the polymerization kinetics of photo-curable ceramic-filled resins. Four grades of alpha-aluminum oxide with different PSDs in an acrylate-based photo-curable resin were investigated. The PSD was measured using a laser diffraction particle size analyzer based on the Mie theory. The quantum of attenuated light was measured with an Ultraviolet/Visible (UV/Vis) spectrophotometer equipped with a modified integrating sphere accessory. UV/Vis measurements revealed that samples with a smaller mean particle size result in larger attenuation in the UV region of the spectrum (i.e., ∼190 nm–420 nm). Moreover, photo-rheology measurements revealed that larger particles generally result in faster polymerization rates without a noticeable change in the degree of conversion. In addition, rheological and sedimentation tests revealed that ceramic-filled resins with a larger mean particle size exhibit lower viscosity and lower sedimentation stability. The findings of this work contribute to the optimization of the process of ceramic powder selection. This results in an increase in the sedimentation stability of ceramic-filled resins, and a customization of their curing behavior.

Continuous manufacturing of vitamin D3 and iron enriched granules by means of a novel twin-screw dry granulation process

A multi-disciplinary approach involving continuous manufacturing (CM) of thermally stable food supplements containing vitamin D3 (VitD3) and iron (Fe ++ ) via a single-step twin-screw granulation (TSG) process was tested in this work. Two selected excipients, namely Neusilin® US2 and corn starch, were used in the work. The particle size distribution and morphology of pre-mixed and post-extruded granules were investigated with a laser diffraction particle size analyzer, sieve analysis, scanning electron microscopy and energy dispersive X-ray (SEM-EDX), X-ray powder diffraction (PXRD), and polarized light microscopy (PLM). The thermal stability of the granules was assessed through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The SEM visualized a good distribution of all ingredients without the forming of any crystals on the extrudate surface, indicating good mixing during the high shear granulation inside the extruder barrel. The FT-IR analysis demonstrates that characteristic vibration peaks of VitD3 were present in all physical mixtures as well as the extruded granules, indicating that VitD3 was stable in the formulations despite the high shear mixing during the TSG. The mean volumetric diameter (Dv50) of the formulation containing Neusilin increased significantly ( P < 0.05) to 90.8-μm when compared with neat Neusilin (71.3-μm) and VitD3 (33.8 μm) confirming granulation, however, no improvement was observed for the corn starch blend. In addition, the calculated Hausner ratio (HR) and Carr's index (CI) suggest similar inter-particulate friction of VitD3 and Neusilin, whereas corn starch showed a difference. The surface elemental analysis confirmed the presence of Fe ++ with a homogenous distribution of the metal in the granules. Overall, for the first time, the blend of VitD3 and iron has been prepared using the CM platform, which has great potential for the intervention of VitD3 and iron deficiencies. • Twin screw dry granulation is employed to develop vitamin D3 and iron granules. • Neusilin and corn starch are used as excipients for the blend. • Particle size distributions and morphology confirm the formation of granules. • Vitamin D3 remained almost constant in the TSG process.

Removal of small elemental sulfur particles by polysulfide formation in a sulfidic reactor

For over 30 years, biological gas desulfurization under halo-alkaline conditions has been studied and optimized. This technology is currently applied in already 270 commercial installations worldwide. Sulfur particle separation, however, remains a challenge; a fraction of sulfur particles is often too small for liquid-solid separation with conventional separation technology. In this article, we report the effects of a novel sulfidic reactor, inserted in the conventional process set-up, on sulfur particle size and morphology. In the sulfidic reactor polysulfide is produced by the reaction of elemental sulfur particles and sulfide, which is again converted to elemental sulfur in a gas-lift reactor. We analyzed sulfur particles produced in continuous, long term lab-scale reactor experiments under various sulfide concentrations and sulfidic retention times. The analyses were performed with laser diffraction particle size analysis and light microscopy. These show that the smallest particles (< 1 µm) have mostly disappeared under the highest sulfide concentration (4.1 mM) and sulfidic retention time (45 min). Under these conditions also agglomeration of sulfur particles was promoted. Model calculations with thermodynamic and previously derived kinetic data on polysulfide formation confirm the experimental data on the removal of the smallest particles. Under the ‘highest sulfidic pressure’, the model predicts that equilibrium conditions are reached between sulfur, sulfide and polysulfide and that 100% of the sulfur particles <1 µm are dissolved by the (autocatalytic) formation of polysulfides. These experiments and modeling results demonstrate that the insertion of a novel sulfidic reactor in the conventional process set-up promotes the removal of the smallest individual sulfur particles and promotes the production of sulfur agglomerates. The novel sulfidic reactor is therefore a promising process addition with the potential to improve process operation, sulfur separation and sulfur recovery.

Preparation of high near-infrared reflectance mica/(Ni, Sb)-co-doped rutile yellow composite pigment via mechanochemical pretreatment and sintering

Mica/(Ni, Sb)-co-doped rutile yellow composite pigment with a high near-infrared reflectance was prepared via mechanochemical pretreatment and subsequent sintering. (Ni, Sb)-co-doped rutile yellow pigment was synthesized by a solid-phase method in the presence of sodium fluoride (NaF) as a mineralizer, and mica was peeled by ultrafine grinding. The pigment, mica and mica/pigment composite were characterized by X-ray diffraction, laser diffraction particle size analysis, nitrogen gas adsorption method, scanning electron microscopy, energy dispersive spectroscopy, ultraviolet–visible–near-infrared spectroscopy, CIEL*a*b* color scales, and infrared irradiation image, respectively. The results show that the temperature of synthesizing a pure rutile pigment in solid-phase reaction is reduced by 100°C due to the addition of mineralizer NaF. (Ni, Sb)-co-doped rutile pigment has better color rendering performance and near-infrared (NIR) reflectance. Ultrafine grinding produces the finer flatty mica particles with fresh reflective surfaces, thus improving NIR reflectance of peeled mica. In mica/pigment composite prepared via mechanochemical pretreatment and subsequent sintering, peeled mica has a synergistic effect on (Ni, Sb)-co-doped rutile pigment particles to further scatter near-infrared radiation through the multiple layer reflections, leading to a better heat insulation. The high near-infrared reflectance of composite pigment increases to 97.72%, and the b* value of the pigment synthesized with 1 wt% NaF is 37.77. For the irradiation infrared lamp, the surface temperature of aluminum plate coated with mica/(Ni, Sb)-co-doped rutile yellow composite pigment is 40.1 ± 0.2°C, which is lower than that of aluminum plate uncoated determined by thermal camera and thermocouple. When aluminum plate coated with mica/(Ni, Sb)-co-doped rutile yellow composite pigment is under sunshine, its surface temperature is 38.6 ± 0.2°C. In addition, the mechanism of preparing the composite pigment via mechanochemical pretreatment and subsequent sintering and the multiple structure reflection effect on peeled mica surface coated with (Ni, Sb)-co-doped rutile yellow pigment particles were also discussed.