Wet Grinding Method Research Articles

Preparation of fly ash supporting nano-TiO2 composite photocatalyst by a wet mechanical grinding method

In this study, nano-TiO2 and FACs were used to prepare a composite photocatalyst (FACs-TiO2) by a wet mechanical grinding method. FACs-TiO2 was fabricated by using nano-TiO2 that was uniformly loaded on the surface of FACs, and the TiO2 particles were 20–30 nm in size. The degradation effect of FACs-TiO2 was comparable to that of commercial nano-TiO2 (P25). The reduction in TiO2 dosage in FACs-TiO2 could markedly reduce TiO2 application costs; thus, it shows promise for practical application.

Synthesis and Characterization Nanosilica from Geothermal Waste by Wet Grinding Method as an Enhanced Oil Recovery (EOR)

In this study, nanosilica for Enhanced Oil Recovey (EOR) has been successfully synthesized using geothermal waste. The method used is wet grinding method with deposition time variations to determine its effect on time deposition on particle size. Characterization using X-Ray Fluoroscene (XRF), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) were also carried out to determine the characteristics of the material. Wettability of nanosilica then was confirmed by contact angle test. Based on the results, it was shown that the purified silica has silica content up to 98.85% with an amorphous phase. The results of Particle Size Analyzer (PSA) show that deposition time determines nanoparticles size. The longer time deposition, the smaller particles can be produced with the best result at 4 days deposition because it can produced the smallest particle at 71.5 nm. The morphology of nanosilica is granular that has been confirmed by SEM. Contact angle test reveals that nanosilica geothermal waste has ability to change wettability. Nanosilica can decrease contact angel of crude oil from 23,3o to 13,9o.

Highly dispersed mesoporous Cu/γ-Al2O3 catalyst for RWGS reaction

The extensive use of fossil energy leads to the wanton emission of CO2 and serious environmental problems. The resource utilization of CO2 is an effective way to solve this problem. The key of CO2 resource utilization is the design and preparation of high active CO2 hydrogenation catalyst. In this paper, supported Cu/γ-Al2O3 catalysts were prepared by wet impregnation and grinding methods, respectively. The physicochemical properties of the prepared Cu/γ-Al2O3 catalysts were characterized by XRD, BET, CO2-TPD and Quasi in-situ XPS, and the reducibility of the precursors was studied by H2-TPR. The results show that Cu content directly affects the Cu0 species crystallinity and even affects the adsorption and activation of CO2 molecules for the Cu/γ-Al2O3 catalyst. The dispersion of Cu0 species in the prepared Cu/γ-Al2O3 catalysts can be further improved by grinding method. The CO2 reaction rate on the Cu/γ-Al2O3 catalyst prepared by grinding method can be significantly increased to 2.12 × 10−5 mol/gcat/s at 400 °C.

Expanded graphite/paraffin/silica phase change composites with high thermal conductivity and low permeability prepared by the solid-state wet grinding method

In this study, expanded graphite (EG)/paraffin (PA)/silica (SiO2) composite phase change materials (PCM), with good thermal conductivity and impermeability, were fabricated for potential applications in solar energy. The EG-PA was first prepared by vacuum adsorption and then encapsulated by SiO2 through solid-phase wet grinding in the presence of sodium silicate. Our results show that the EG-PA-SiO2 composite have optimal properties when the mass ratio of raw material is PA: sodium silicate: H2O = 1:9:2:8. The latent heat of melting of the EG-PA-SiO2 composite prepared at this mass ratio is 106.2 J/g. The core material loss ratio, after washing with petroleum ether, is 4.79%. The thermal conductivity is 2.053 W/m·K, which is 8.5 times higher than that of pure paraffin wax, and the melt permeability is 9.35% after 120 min at 60 °C. Under simulated sunlight, the time required for the composite material to change from 30 °C to 65 °C is reduced by 70.78% compared to PA and the heat absorption and release times are nearly unchanged under multiple cycles. These results indicate that the material has a stable photothermal conversion efficiency.

A comparative analysis of grinding of AISI D2 tool steel under different environments

Difficult-to-cut material, i.e., AISI D2 tool steel, has been widely adopted in metalworking industries to manufacture dies for piercing, blanking, drawing and thread rolling due to its excellent wear resistance and non-deforming properties. This article attempts an experimental study to determine the effect of cryogenic coolant (liquid nitrogen) on the grindability of AISI D2 tool steel as work material and its results are compared with the conventional dry and wet grinding methods. The effects of the cryogenic coolant on force components (i.e., tangential force, Ft and normal force, Fn ), specific grinding energy (u), force ratio, surface roughness parameters (Ra and Rz ) and microstructure were observed. The comparison results indicate a significant reduction in grindability indices such as 64% and 44% in Ft , 54% and 34% in Fn , 46% and 30% in Ra and 40% and 34% in Rz , respectively under cryogenic grinding at higher downfeed as followed to dry and wet grinding. The grinding performance in Ft , Fn , u and Ra was also improved with an increased delivery pressure of the liquid nitrogen (LN2). From the results, it is concluded that cryogenic coolant offers an influential method to improve grinding performance and surface integrity of AISI D2 tool steel.

Superhydrophilic wollastonite-nanoTiO2 composite photocatalyst prepared by a wet grinding method: The effects of carriers and their application in the self-cleaning coatings

A wollastonite-nanoTiO2 composite (WOT-PC) was prepared by a facile mechanochemistry method, which is expected to improve the photocatalytic performance and its recycling ability. According to the results of photocatalytic degradation, the degradation extent of the 10 ppm (10 mg/L) methyl orange solution was 99% after 20 min UV irradiation, indicating the good photocatalytic performance of WOT-PC. The XPS results suggests that stable Ca–O–Ti and Si–O–Ti bind wollastonite and nanoTiO2 together chemically. Furthermore, Ca–O–Ti may promote the separation efficiency of photoinduced electrons and holes during irradiation. To study the bending of energy structures of nanoTiO2, UPS was used. The results showed a negative shift of the energy structure bands and a positive shift of the Fermi level to TiO2, revealing that electrons more easily move to the surface of TiO2 after wollastonite supports nanoTiO2. The WOT-PC coating exhibits great self-cleaning ability because of its superhydrophilicity and photocatalytic performance, reflecting the promise of WOT-PC as an outdoor wall coating in practical applications.

Optimization of Planetary Ball Mill Size on Physicochemical Properties and Dissolution Rate of Nimodipine- PVP K-30

Nimodipine is a compound that is insoluble in water and is included in the biopharmaceutical classification system (BCS) class II. This study looks at the characterization of nimodipine-PVP K-30 with the wet grinding method using a planetary ball mill at 200 rpm with large and small ball sizes. Nimodipine was made into 3 formulas, namely a physical mixture (1:0.6), formula 1 with 24 large balls (1:0.6), and formula 2 with 143 small balls (1:0.6). Evaluation of physicochemical properties includes size distribution, surface morphology, functional group analysis, crystallinity properties, thermal properties, assay, and dissolution profile. The dissolution results of nimodipine, CF, F1, and F2 at 60 minutes were 33.63%, 39.48%, 74.00%, and 53.99% respectively. The evaluation results showed that in general nimodipine-PVP K-30 could improve the physicochemical properties and increase the dissolution rate of nimodipine.

Mechanical performance, hydration characteristics and microstructures of high volume blast furnace ferronickel slag cement mortar by wet grinding activation

Replacement of cement clinker by industrial wastes has been verified as an effective way to reduce carbon emissions. To realize the application of blast furnace ferronickel slag (BFFS) in high volume in cement mortar, wet grinding was used to improve the activity of BFFS. Three fineness (D50 = 13 μm, 5 μm and 2.5 μm) and three contents (30%, 50% and 70%) of BFFS were investigated comparatively. Isothermal calorimetry, X-ray diffractometer(XRD), Thermal analyzer (TG), Fourier Transform Infrared (FTIR), Mercury injection apparatus (MIP) and Scanning Electron Microscope (SEM) were employed to examine the hydration process and microstructures. The results showed that the pozzolanic behavior and filling effect of BFFS could be improved remarkably by wet-grinding method. The compressive strength of specimens with 50mirc% and 70% BFFS (D50 = 2.5 μm) after curing 28 days could reach 109% and 97% of that of control cement specimens respectively. The results of XRD, TG and FTIR revealed that refined BFFS was involved in pozzolanic reaction at age of 3 days, the effect was more significant with the grinding duration extending. Furthermore, the pore size distribution and the porosity were optimized obviously. Results highlight that wet-grinding treatment of BFFS provided an effective way to improve the early and late age strength of high-volume BFFS cement mortar.

Performance analysis of dye-sensitized solar cells with various MgO-ZnO mixed photoanodes prepared by wet powder mixing and grinding

In this study, photoanodes of a dye-sensitized solar cell (DSSC) were made by adding various weight percentages (0∼9 wt%) of MgO nanopowder to ZnO nanopowder with a different wet powder mixing and grinding method. For the MgO/ZnO DSSCs, the addition of 1 wt% MgO can achieve maximum short-circuit current density (4.00 mA/cm2) and maximum photovoltaic conversion efficiency (1.03%), which was 39% and 27% better than those of the reference ZnO DSSCs, respectively. When a small amount of MgO was added, the electron transport rate or the efficiency of electron injection into photoanodes was improved. However, when a large amount of MgO was added, the number of carriers generated by light was lowered, which led to performance degradation in DSSCs. Preparing photoanodes by adding a small amount of MgO to ZnO can thus effectively improve the photovoltaic performance of ZnO DSSCs.

Heat-cured cement-based composites with wet-grinded fly ash and carbide slag slurry: Hydration, compressive strength and carbonation

Fly ash (FA) with high glassy phase content is a pozzolanic material with low activity, while carbide slag is a solid waste with portlandite crystals embedded in the impurity phases. Herein, wet-grinding method was used twice to improve the pozzolanic reactivity of FA and promote the dissolution of embedded calcium hydroxide in the CS as a lime source, respectively. Wet-grinded FA slurry (WFA) with D50 of 2.5 μm and wet-grinded CS slurry (WCS) with D50 of 3.0 μm were prepared. It was found that setting times, hydration heat release, early and late compressive strength, carbonation resistance of high volume WFA blended composites were significantly enhanced by WCS, attributed to the pre-dissolved calcium resource and alkali reserve. However, an excessive amount (12 wt%) of WCS addition causes an abnormal decrease in strength, due to the microstructure degradation by coarse portlandite crystals. Higher proportion of C-S-H might be ready for carbonation in high volume WFA blended composites, due to the promoted Al incorporation in C-S-H by wet-grinding.

Detailed performance analysis of the wet extractive grinding process for higher calcium yields from steelmaking slags

In this paper, the wet extractive grinding method for efficient recovery of calcium from steelmaking slags was studied. This work supports the Sustainable Development Goal of UN, SDG12: Responsible Consumption and Production by reducing the need for virgin limestone and aiming to circular solutions. The extraction is the first step in our pH-swing process, wherein CaO from the slag using a NH4Cl-water solvent is dissolved. After filtering the solid phase, CO2 is bubbled into the Ca-rich solution to produce precipitated calcium carbonate (PCC). Traditional mechanical mixing for extraction stage is found problematic since it requires energy intensive preliminary fine-grinding to be effective. Effects of the processing time (1.25–20 min), and the slag-to-solvent ratio (SLR = 30–120 g/L) were studied here in detail in the extractive grinding process. Inductively coupled plasma-atomic emission spectroscopy (ICP-OES), energy-dispersive X-ray spectroscopy (SEM-EDS), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) analyses were used for the detailed physical and chemical characterization of raw and residual slag powders. Results showed that Ca-yield increases from 35 to ~70% via the EG process as comparison with mechanical mixing. Results also show that the rate of the process also significantly increased.

The Effects of Dry and Wet Grinding Processes on The Salt Quality

Studies were conducted on the salt quality, such as NaCl percent and whiteness achieved by dry and wet grinding methods. Crude solar salt is carefully collected from traditional solar salt ponds to ensure the uniformity of the sample. Several salt processing methods were applied in this research, such as washing, grinding, and dewatering by centrifuge hydro extractor and drying. The effect of reducing salt particle size to 0.6 and 0.25 mm was also studied. The dry grinding method is conducted before the washing stage, while the wet grinding method is applied after the washing stage. Both dry and wet grinding methods provide high-quality salt products, indicating high NaCl percent and whiteness. The dry grinding method produces higher NaCl percent and whiteness than the wet grinding method. However, the wet grinding method was better in water management and equipment durability with loss of salt losses during the washing stage. Finally, both grinding methods have advantages and disadvantages, so for developing the salt processing industry, both methods should be correctly chosen and match product output requirements.

Preparation of Ultrafine CL‐20 by Wet Grinding Method and the Study on Its Properties

AbstractIn this paper, ultrafine CL‐20 was prepared by wet grinding procedure. The morphology, particle size, sample composition, and crystal structure of CL‐20 before and after grinding were detected by scanning electron microscope, laser granulometer, infrared Raman Spectroscopy, and X‐ray diffraction instrument. The thermal decomposition, mechanical sensitivity, shock wave sensitivity, flame sensitivity, bulk density, and rheological property of CL‐20 based explosives were tested. The results indicated that the crystal form of CL‐20 was retained as ϵ‐form after wet grinding. The ground CL‐20 was superior in physical properties to the raw CL‐20, such as smaller particle size, smooth surface, less mechanical sensitiveness, and lower flame sensitivity. However, the thermal stability was slightly decreased. Moreover, the bulk density of ground CL‐20 was higher, which leading to an increase in density of shaped charge column. The viscosity of the CL‐20 based cast explosive formulation was effectively reduced, that can improve the process of explosive formulation and the process adaptability. In addition, under high strain rate loading, the impact safety of the explosive prepared with ground CL‐20 is improved.

Study Evaluation Maternity Nutrition and Pregnancy In Vitro and In Vivo—Progesterone Nanocrystal Injection

In this study, the insoluble drug, progesterone, was formulated into a progesterone nanocrystal injection to improve the saturation solubility, release rate, and efficacy of progesterone, as well as to increase the relative bioavailability of progesterone, reduce the subsequent irritation, and minimize the toxicity; the advantages and feasibility of the progesterone nanocrystalline injection in the prevention of premature delivery and protection against pregnancy-associated risks in pregnant females was evaluated. The wet grinding method was used to prepare the progesterone nanocrystalline injection; its morphology, particle size, and potential were characterized by transmission electron microscopy. Crystal structure was analyzed by X-ray powder diffraction; the solubility of the injection and the progesterone drug substance in water, and the In Vitro release of the drug were evaluated for its nanometer effect In Vitro. Rabbits were injected with the progesterone nanocrystal injection as well as commercially available progesterone injections for evaluation in vivo. The formulation process of a progesterone nanocrystal injection is feasible. The crystal form is stable and the particle size is uniform. Moreover, we found that it improves the release rate, saturation solubility, and bioavailability of progesterone, while reducing muscle irritation. The results have clinical research significance.

Effects of grinding media on the material properties and strengthening mechanism of silicon production

In this study, we evaluated the characteristics and applications of carbonaceous materials, which play a vital role in silicon production. Specifically, we conducted an exploratory study on biomass and petroleum coke (PC) performance improvement in response to different grinding media, and discussed the outcomes of our experimental results in conjunction with thermodynamic and kinetic analysis. Furthermore, we comprehensively analyzed the strengthening mechanism using Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, and scanning electron microscopy (SEM). The results showed that the initial reduction reaction temperature was significantly lowered by using the wet-grinding method. Even more remarkably, the maximum reaction rate increased from 62% to 157% when organic solvent was added to the mixture during the wet-grinding process and the proportion of decreased activation energy increased from 15.34% to 22.35%, as compared with dry-blending. Thus, the mixtures’ reactivity improved by using wet-grinding, especially after adding organic solvent, which increased the carbothermic reduction utilization of PC and biomass. A potential primary cause may be related to the “like dissolves like” interaction between organic solvents and organic functional groups in carbon materials. This study has important implications for developing low-cost, low energy consumption of silicon, as well as promoting clean, efficient production.

Nano-carbide slag seed as a new type accelerator for Portland cement

In present work, a novel nano-CS seed was prepared by wet-grinding method and added to cement to accelerate the early hydration. With 5% nano-CS seed, the initial and final setting time was clearly shortened by 61.4% and 51.7% respectively; the dormant period and the main hydration peak was notably advanced by 52.9% and 43.5% respectively. Early compressive strength, especially the 8-hour strength, was greatly promoted by the nano-CS seed by 3350%, with 5% nano-CS seed. It was speculated that the early-hydration and early-strength was accelerated by weakening the electrical double layer shielded around the silicate phase, thus shortening the dormant period. Results highlighted that the prepared nano-CS seed in present work is expected to be practically used as a new type accelerator.

Nano-treatment of Autoclaved Aerated Concrete Waste and Its Usage in Cleaner Building Materials

Autoclaved aerated concrete waste (AACW) was used as a raw material to prepare nucleation seed for acceleration of Portland cement. Nano AACW seed with median particle size of 324 nm was prepared by wet grinding method. Both the electrical conductivity and pH value of nano AACW suspension were obviously improved. Both the setting times and intensity of the main hydration heat peak were promoted by nano AACW, indicating the possibility of AACW suspension as nucleation seed. The early age compressive strength before 3 days was also clearly improved by nano AACW, with no negative effect on the late age strength. Furthermore, the reduced CH content with dosage of nano AACW indicates that nano AACW not only plays a role of nucleation seed in cement hydration, but also has a certain pozzolanic reaction.

Improving interfacial electrochemistry of LiNi0.5Mn1.5O4 cathode coated by Mn3O4

In this work the surface of LiNi0.5Mn1.5O4 (LMN) particles is modified by Mn3O4 coating through a simple wet grinding method, the electronic conductivity is significantly improved from 1.53×10−7 S/cm to 3.15×10−5 S/cm after 2.6 wt% Mn3O4 coating. The electrochemical test results indicate that Mn3O4 coating dramatically enhances both rate performance and cycling capability (at 55 °C) of LNM. Among the samples, 2.6 wt% Mn3O4-coated LNM not only exhibits excellent rate capability (a large capacity of 108 mAh/g at 10 C rate) but also shows 78% capacity retention at 55 °C and 1 C rate after 100 cycles.

The “electric-dipole” effect of Pt–Ni for enhanced catalytic dehydrogenation of ammonia borane

In this work, we prepared the PtNi alloy nanoparticles on Al2O3 (Al2O3–PtNi) via a simple wet-grinding method followed by a thermal reduction process. The as-prepared Al2O3–PtNi displayed a higher TOF of 426.84 molH2 (molPt·min)−1 toward the dehydrogenation of AB (ammonia borane) than Al2O3–Pt and Al2O3–Ni. Based on the theoretical calculations, an “electric-dipole” effect generated by the neighboring Pt–Ni atoms was found to facilitate the catalytic dehydrogenation process of ammonia borane (AB). The external electric field produced by the Pt–Ni dipole can elongate the B–H bond and increase the negative charges of H atoms on the BH3 group, which helps to activate the B–H bond in the AB molecule, and thus enhances the kinetic process of catalysis.

Mineralogical and surface chemical characterization of flotation feed and products after wet and dry grinding

Wet processing after crushing is common practice in mineral processing circuits involving flotation but the need for more efficient water management has increased interest towards dry processing. In this study the effects of both wet and dry grinding on flotation of one sulphidic and one non-sulphidic ore were compared. Bench scale flotation tests were carried out and various microscopic and spectroscopic methods such as FESEM and XPS were used in characterization of flotation feeds and products. Bulk surface charge properties were tested with mass titration.Clear differences in surface properties and flotation results were observed from the wet and dry grinding methods, which encourages further research. Wet grinding was beneficial for the energy efficiency for both ores and promoted the selectivity of flotation particularly with sulphidic ore. The wear of the mill and grinding media seemed more extensive in wet grinding. Dry grinding produced more fine particles tightly attached to the surfaces, caused by the higher surface charge of the dry ground ore especially with non-sulphidic ore.