Ball Milling Research Articles

Mechanochemical Synthesis ofβ-Sulfenylated Ketones and Esters.

For the first time, ball milling has been employed in the solvent-free synthesis of sulfur-functionalized materials from thiols and α,β-unsaturated ketones and esters, using potassium carbonate as a transition metal-free catalyst. This environmentally friendly protocol makes use of easily accessible reagents to prepare β-sulfenylated carbonyl compounds with yields exceeding 91% under ambient air and solvent-free conditions. Additionally, this innovative synthetic strategy enables the modification of chalcones, compounds with significant medicinal and synthetic potential. The reactions are efficient and easily scalable to gram quantities, offering substantial benefits for practical applications.

Fabrication of Ag Nanoparticle-Embedded Covalent Organic Frameworks for Oil Gel with Long-Term Stability and High Lubrication Performance.

In previous reports, covalent organic frameworks (COFs) have demonstrated significant potential as lubricant additives. Herein, we embedded Ag nanoparticles in the DT-COF (polycondensation polymer of 2,5-dihydroxyterephthalaldehyde and 4,4',4″-(1,3,5-triazine-2,4,6-triyl) trianiline) matrix via the ball milling method and utilized this composite (Ag@DT-COF) as an additive for supermolecule oil gel. The low molecular weight gelator effectively mitigates the dispersion challenges of COFs in lubricant oil, while the embedded Ag nanoparticles enhance the repairing effect and antipressure performance of the lubricant. The resulting Ag@DT-COF gel exhibits a reduction in the average friction coefficient and wear volume of base oil by 46.0% and 87.5%, respectively, and increases the load-carrying capacity to 750 N. The remarkable tribological properties are attributed to the easy adsorption of DT-COF, antiwear characteristic of Ag nanoparticles, and the gelator that ensures the long-term stability of oil gel.

Impact of Ball Milling on the Microstructure of Polyethylene Terephthalate.

Polyethylene terephthalate (PET) is a semi-crystalline polymer that finds broad use. Consequently, it contributes to the accumulation of plastics in the environment, warranting PET recycling technologies. Ball milling is a commonly used technique for the micronization of plastics before transformation. It has also recently been reported as an efficient mixing strategy for the enzymatic hydrolysis of plastics in moist-solid mixtures. However, the effect of milling on the microstructure of PET has not been systematically investigated. Thus, the primary objective of this study is to characterize the changes to the PET microstructure caused by various ball milling conditions. PET of different forms was examined, including pre- and post-consumer PET, as well as textiles. The material was treated to a range of milling frequencies and duration, before analysis of particle size, crystallinity by differential scanning calorimetry and powder X-ray diffraction, and morphology by scanning electron microscopy. Interestingly, our results suggest the convergence of crystallinity to ~30% within 15 minutes of milling at 30 Hz. These results are consistent with an equilibrium between amorphous and crystalline regions of the polymer being established during ball milling. The combined data constitutes a reference guide for PET milling and recycling research.

Protocols for bulk off-line fluid inclusion extraction for the analysis of δ13C-CH4 and δ13C-CO2 using a cavity ring-down spectroscopy (CRDS) analyser

Fluid inclusions are a window into deep geological fluids, providing unique access to their nature and composition. The isotopic composition of CO2 and CH4 hosted in fluid inclusions is a powerful proxy to assess the origin and transformation of deep geological fluids, giving insights into carbon sources, fluxes, and degassing in a wide variety of geodynamic settings. Over the last 5 decades, techniques have been developed to extract fluid inclusions from their host minerals and measure their bulk composition. These techniques are often challenged by analytical artifacts including high blank levels of CO2 and CH4, fluid re-speciation, gas adsorption, and diffusion. Since these processes may alter the pristine composition of gases liberated from fluid inclusions, rigorous protocols are needed in order to evaluate the isotopic integrity of the extracted volatile species. In this study, we introduce new protocols for bulk off-line fluid inclusion extraction for the analysis of δ13C-CH4 and δ13C-CO2 using a Cavity Ring-Down Spectroscopy (CRDS) analyser (Picarro G2201-i). Two mechanical fluid extraction techniques are compared: ball milling in ZrO2 jars and sample crushing in a stainless steel sealed tube under a hydraulic press. Blanks and isotopically labelled tests with the ball milling technique suggest that rotation speed, grinding stock filling degree and filling type alter the CH4 and CO2 concentrations and isotopic compositions measured by the CRDS analyser. In contrast, the crushing technique does not generate measurable quantities of blank CH4 and CO2. The protocols presented in this study allow to extract, detect, and analyse δ13C of CH4 and CO2 for concentrations above 10 and 1,000 ppm respectively. Interlaboratory experiments allowed to replicate previously measured δ13C-CH4 values in natural fluid inclusions within 1‰ with both extraction techniques. This study highlights the potential of combining simple bulk off-line fluid inclusion extraction techniques with a CRDS analyser for δ13C analysis of CO2 and CH4 without gas separation being required.

Revisiting Stability Criteria in Ball‐Milled High‐Entropy Alloys: Do Hume–Rothery and Thermodynamic Rules Equally Apply?

Stability descriptors for the formation of solid solutions can be divided into two categories: inspired by Hume–Rothery rules (HRR) and derived from thermodynamic approaches. Herein, HRRs are extended from binary to high‐entropy alloys (HEAs) focusing on compositions prepared by ball milling. Parameters describing stability criteria are interrelated and implicitly account for the microstrains’ storage energy, more determinant than entropy increase in stabilization of HEAs and more effective in bcc structures than close‐packed ones (fcc and hcp). An effective temperature, Teff, is defined as the ratio between increase in metallic bonding energy of solid solutions with respect to segregated pure constituents and configurational entropy. This versatile parameter is used as a threshold for stabilization of HEAs at equilibrium and out of equilibrium. When Teff is below room temperature, HEA would be stable at equilibrium. When Teff is below melting temperature, HEA would be obtained by rapid quenching. Limitations related to electronegativity differences remain valid in mechanically alloyed solid solutions. However, ball milling broadens the allowed differences in atomic size to form HEA. Moreover, thermodynamic criteria can be surpassed in these systems, allowing the formation of single‐phase solid solutions beyond the compositional range predicted by those criteria.

Every reaction Detail Matters: An in silico driven Step-by-Step Guide to understand the B2O3-Catalyzed CO2 to cyclic carbonates conversion

The catalytic conversion of carbon dioxide (CO2) to cyclic organic carbonates (COCs) via cycloaddition with epoxides offers a dual benefit of reducing CO2 emissions while producing valuable chemical products. In this detailed in silico study, we employ density functional theory (DFT) to meticulously investigate the mechanisms underlying the B2O3/n-NBu4Br-catalyzed cycloaddition of CO2 and epoxides, following a step-by-step approach according to the reaction details. We provide a comprehensive comparison of the non-catalyzed, n-NBu4Br alone, and B2O3/n-NBu4Br-catalyzed pathways, emphasizing two distinct active sites within the B2O3 framework: Site 1 (six-membered boroxol ring) and Site 2 (open chain configuration). Our computational analysis highlights that the Site 1-catalyzed reaction pathway is more favorable, featuring a lower overall energy barrier of 26.8 kcal/mol, compared to 32.5 kcal/mol for the Site 2-catalyzed pathway. Detailed intrinsic bond orbital (IBO), natural adaptive orbital (NAdO) and distortion-interaction analysis (DIA) reveal significant differences in bonding properties and energy interactions, elucidating why Site 1 exhibits superior catalytic activity over Site 2. These findings are corroborated by experimental observations, which indicate that ball milling B2O3 increases defect sites, thereby enhancing exposure of active sites Site 1 and improving catalytic performance. This study provides an in-depth understanding of how the intrinsic properties of boron active sites influence the catalytic efficiency of B2O3, offering valuable insights for the design and optimization of metal-free catalysts for CO2 conversion.

Stirred media mills of fine and ultrafine grinding for subsequent beneficiation operations

This paper presents a brief review of the designs, characteristics, and operating parameters of Stirred media mills supplied by foreign manufacturers. An analysis of information on Stirred media mills , which are used to improve the efficiency of beneficiation and metallurgical operations, is carried out using available publications. The obtained results indicate the inexpediency of using conventional drum ball mills for flotation separation of ores and concentrates with a fine interpenetration of minerals. The application of conventional mills in extraction of ores and concentrates resistant to cyanidation, where gold is finely disseminated in sulfides, is limited by their high power consumption and the corresponding operating costs. In this work, different types of Stirred media mills are considered, including their vertical and horizontal types. The advantages of Stirred media mills over conventional ball mills, particularly in terms of energy efficiency, are noted. The designs and main characteristics of Stirred media mills , which have received wide application, are presented. According to the data presented in the reviewed publications, the main parameters determining the grinding process in such mills are outlined, including the ratio of bead size to mill feed size, density of grinding medium, density of pulp in the mill, volume loading of beads, stirring speed, etc. The conducted analysis of literature data indicated high efficiency of mills based on agitation of grinding media for fine and ultrafine grinding of ores and concentrates in comparison with conventional ball mills. Given that the volume of ores and concentrates resistant to processing by conventional methods is increasing, the application of Stirred media mills is expected become more widespread, thereby increasing the efficiency of subsequent beneficiation and metallurgical operations.

Entrapment of multi-scale structure of alginate beads stabilized with cellulose nanofibrils for potential intestinal delivery of lactic acid bacteria

Soybean cellulose nanofibrils (SCNFs) were formed by autoclave-enzymatic hydrolysis combined with ball milling. SCNFs were blended with sodium alginate (SA) to encapsulate lactic acid bacteria (LAB) through inotropic gelation. The effect of SCNFs on the multiscale structure of SA beads, leading to changes in the survival and release of LAB during simulated digestion, was investigated. Microscopy and rheological testing indicated that SCNF10–30 was well-dispersed in the SA paste in the form of interlaced nanofibrils, and could reduce the deformation of the paste under stress by 47.31 %. Multiscale structural analysis indicated SCNF10–30 not only increased the immobilized water of SA beads by 15.59 % by coordinating calcium, but also regulated the in situ-assembly of SA beads, including an increase in the scale of dimers from 6.73 nm to 8.32 nm and improved arrangement, thus forming a dense gel network. LAB viability of SA-SCNF10–30 in simulated digestion was increased by 1.3 log CFU/g compared to SA beads. Cellulose nanofibrils improved gastrointestinal survival and controlled release of LAB better than fiber rods. This study provides a strategy to regulate the multiscale structure of SA beads through nanofibrils to enable stabilization and sustainable release of LAB in gastrointestinal fluids.

Upcycling Spent Graphite from Li-ion Batteries into Cu/Expanded Graphite Composites as high-performance electromagnetic wave absorbers.

With the widespread adoption of lithium-ion batteries and modern electronic components in both daily life and industrial production, there is a growing focus on the high-value recycling of spent lithium-ion batteries and the development of absorbents with high electromagnetic wave absorption capabilities. Efficiently regenerating recycling graphite from spent batteries through low-cost methods and utilizing it to prepare high-performance electromagnetic wave absorbing materials holds significant importance in addressing both the utilization of waste graphite and electromagnetic pollution issues simultaneously. This work presents a method to transform spent graphite into expanded graphite with a three-dimensional conductive structure using an enhanced Hummer's treatment and thermal reduction process. Subsequently, Cu/EG composite materials were efficiently prepared through straightforward mechanical ball milling and calcination. The unique honeycomb-like porous structure of expanded graphite facilitates the reflection and scattering of electromagnetic waves, electron transfer, and defect polarization. Additionally, the incorporation of copper nanoparticles improves the conduction loss and enhances interface polarization, allowing for precise tuning of the composite material's absorption performance. The results demonstrate that Cu/EG composite materials exhibit excellent electromagnetic wave absorption performance. The Cu/EG(1:3) sample exhibits effective absorption in the C, X, and Ku bands, achieving a minimum reflection loss (RLmin) of -54 dB and a maximum effective absorption bandwidth (EABmax) of 5.28 GHz. This performance is attained with a thickness of just 2.2 mm and a filler content of only 15 wt.%.

Effects of heteroatom-doped hierarchical porous carbon on hydrogen storage properties of MgH2

In this paper, the nitrogen doped (N-HPC), nitrogen and phosphorus co-doped hierarchical porous carbon (NP-HPC) are prepared by cross-linking phytic acid and poly pyrrole/aniline precursor, respectively. They are mixed with MgH2 by high-energy ball milling, and then their effects and mechanisms on the hydrogen absorption and desorption properties of MgH2 are investigated. Meanwhile, the hydrogen storage properties of MgH2 added with graphite (G) are also compared. The results show that the additions of NP-HPC, N-HPC, and G all exhibit the catalytic effect on the hydrogen absorption and desorption of MgH2. As for the hydrogen desorption, the catalytic effect is enhanced in the order of N-HPC, G and NP-HPC. Compared with pure MgH2, the hydrogen desorption temperature is reduced by 65.3 °C, 79.6 °C and 91.1 °C, respectively. Among them, the MgH2 + NP-HPC system can release 5.17 wt% hydrogen at 300 °C within 30 min. First-principles calculations reveal that the P-doped and vacancy-containing carbon materials significantly reduce the H2 recombination barrier from the surface of MgH2 and distort the atomic structure of near-surface layer of MgH2, which in turn weakens the Mg-H bond strength. This may be the intrinsic reason for the excellent catalytic effect of NP-HPC and vacancy-containing G on the hydrogen desorption performance of MgH2.

The role of biochar nanoparticles in reducing salt stress in tomato (Solanum lycopersicum) plants grown in fields

Soil salinization is a major threat to global food security, affecting over 20 % of cultivated land and reducing yields of important crops like tomato (Solanum lycopersicum). This field study explored the potential of biochar nanoparticles (BNPs) derived from rice straw to mitigate salt stress in tomato plants. The BNPs, prepared by pyrolysis at 350 ℃ and ball milling, had an average size of 130.32 nm. Tomato plants were grown for 12 weeks in soil with 0.2 % NaCl (w/w) and BNPs at 0.5, 1, or 2 ‰ w/w. Controls included unamended soil, soil with NaCl only, soil with BNPs only, and regular biochar with and without NaCl. BNPs significantly improved growth, biomass, and fruit yield of salt-stressed tomato plants. The 2 ‰ BNP treatment increased fruit yield by 115.05 % compared to salt stress alone. Stem fresh and dry weights increased by 35.64 % and 79.71 %, respectively, while root fresh and dry weights increased by 138.27 % and 68.35 %, respectively. BNPs enhanced fruit quality, with higher concentrations showing better effects. BNPs alleviated salt stress by regulating ion homeostasis, limiting Na translocation to leaves and fruits (reducing Na content by 35.15 % in leaves and 16.06 % in fruits), improving K content and Na/K ratio, and influencing Mg and P absorption and translocation. The nanoscale size, high surface area, and enhanced reactivity of BNPs allow them to penetrate plant tissues and interact with ion transport components. This study demonstrates the potential of BNPs as a sustainable approach for enhancing tomato salt tolerance in the field. Using crop residues for BNP production supports circular economy and sustainable agriculture. This approach holds potential for enhancing sustainable crop production under saline conditions, contributing to food security and the development of resilient agricultural systems in challenging environments.

Effect of hydroxylated boron nitride and boron nitride nanosheets on the properties of doped organosilicone rubber composites

As the electronic industry develops rapidly, the miniaturisation, integration and multifunctionality of electronic devices have resulted in a dramatic increase in power density, and the heat dispersal of electronic devices has attracted much attention. In this work, hydroxylated hexagonal boron nitride (BN-H) was obtained by hot alkali treatment, and boron nitride nanosheets (BNNS) with a thickness of about 4 nm were obtained by boric acid-assisted ball milling stripping. The effects of different types of fillers as well as filler contents on the thermally conductive and mechanical performance of organosilicon composites were also compared. Notably, when BN-H and BNNS thermally conductive fillers were added at 12 wt%, the thermally conductive coefficients of the composites were 0.4831 W·m−1·K−1 and 0.7131 W·m−1 K−1, respectively, which were 183% and 318% of higher than that for the pure silicone rubber (SR, with a thermally conductive coefficient of 0.1706 W·m−1·K−1). In addition, in respect of mechanical performance, the tensile strengths of SR/BN-H and SR/BNNS composites with a filling level of 12 wt% were 3.59 MPa and 3.89 MPa, respectively, and the storage moduli were 4501 MPa and 4583 MPa, respectively, which were improved to a certain extent compared with pure SR. The present work provides an effective way to develop organosilicone rubber composites with good thermal conductivity and mechanical properties by boric acid assisted ball milling to strip boron nitride in the field of electronics packages.

Enhanced high-temperature mechanical properties and strengthening mechanisms of chemically prepared nano-TiC reinforced IN738LC via laser powder bed fusion

Fabrication of high-strength nickel-based composites to meet the demanding service requirements in aerospace environments is a significant challenge. This paper introduces the wet chemical method to prepare the nano-TiC reinforced IN738LC. In contrast to the conventional ball milling approach, this method attains superior attachment of nanoparticles. By employing a full-factorial experimental design, the correlation between Laser-powder bed fusion (L-PBF) processing parameters and the porosity, micro-hardness, and high-temperature tensile strength of as-built samples was examined. The results indicate that the optimal processing parameters are a laser power of 225 W, scanning speed of 750 mm/s, and hatch space of 0.09 mm, with a Volumetric energy density (VED) of 111.1 J/mm3. Compared to IN738LC, the chemically prepared TiC-IN738LC exhibits a 45 % increase in room temperature tensile strength (400 MPa) and a 65 % increase in high-temperature tensile strength (120 MPa). Compared with ball-milled TiC-IN738LC, the chemically prepared samples present superior microstructure with more equiaxed grains. The morphological analysis of the tensile samples reveals that the presence of dimples are crucial in enhancing the ductility properties. Furthermore, this study identifies the Orowan strengthening mechanism and the grain refinement strengthening mechanism as the principal mechanisms of reinforcement by nano-ceramics.

A Hybrid Method for Identifying Critical Failure Modes in a Ball Mill

The reliability of a ball mill is crucial for the seamless operation of ore processing and other industrial plants, where unexpected equipment failure or downtime can result in significant financial losses and reduced production efficiency. Thus, this paper examined a hybrid method for identifying critical failure modes in a ball mill using the Failure Modes, Effects, and Criticality Analysis combined with the Complex Proportional Assessment with Grey Numbers (COPRAS-G). The COPRAS-G method was employed to assess the criticality of various failure modes by determining the weights of significant failure modes in the bearing, gearbox, motor, and shaft components of a ball mill. It was observed that gear seal failure is the most critical failure with percentage contribution (Ni) of 100%, while bearing wear is the least critical failure with percentage contribution (Ni) of 62%. The result suggests that failure modes of gear seal failure, gear pitting, motor bearing fatigue, and shaft fracture are regarded as the main contributors to failure with percentage contribution (Ni) of 100%, 97%, 87% and 83% respectively. Current ball mill maintenance includes corrective, preventive and predictive maintenance. For failure modes with high criticality, predictive maintenance was advised, while for moderate and low criticality, corrective and preventive maintenance were advised.

Novel self-pretreatment of biomass by in-situ preparation of acid-assisted carbohydrate-derived DES

Deep eutectic solvents (DES) can greenly and efficiently fractionate biomass, but their utilization efficiency is severely limited by the high ratio of DES required and the wasted hemicelluloses released during the pretreatment. Herein, this work first developed a novel self-pretreatment of biomass by in-situ preparation of acid-assisted carbohydrate-derived DES with the aid of ball milling to facilitate enzymatic hydrolysis. The effect of hydrogen bond acceptor types, water content, acid content, and ball-milling time on enzymatic hydrolysis was studied systematically. Under the optimal condition (tetrabutylammonium chloride (TBAC), 1000 wt% H2O, 100 wt% acids, ball milling for 2 h), the yields of glucose and xylose produced from the pretreated substrates after enzymatic hydrolysis were >99.9 % and 88 %, respectively. Furthermore, the structural integrity of the residual lignin was well-preserved, making it suitable for positional structural characterization and ideal substrates for lignin degradation. Characterization suggested that the hemicelluloses fragments via in-situ acid hydrolysis acted as hydrogen bond donors and combined in situ with TBAC to form DES. This strategy avoided the use of high dosages of DES and the wastage of hemicelluloses, and promoted the sustainability of the entire biorefinery process.

Co-Amorphous Solid Dispersion System for Improvement in Dissolution Profile of N-(((1r,4r)-4-((6-fluorobenzo[d]oxazol-2-yl)amino)cyclohexyl)methyl)-2-methylpropane-2-sulfonamide as a Neuropeptide Y5 Receptor Antagonist.

Background/Objectives: Brick dust molecules exhibit high melting points and ultralow solubility. Overcoming this solubility issue is challenging. Previously, we formulated a co-amorphous system for a neuropeptide Y5 receptor antagonist (NP) as a brick dust drug using sodium taurocholate (ST) to improve its dissolution profile. In this study, we have designed a ternary amorphous system involving polymer addition to further improve a co-amorphous system. Methods: The amorphous samples were prepared by the ball milling. The thermal and spectroscopic analyses were performed, and the isothermal crystallization and dissolution profiles were evaluated. Results: The ball milling of NPs, ST, and each of the three types of polymers successfully converted crystalline NPs to amorphous NPs. Thermal analysis confirmed the formation of a single amorphous phase. The infrared spectra revealed a specific interaction between an NP and ST in the co-amorphous system. Moreover, the intermolecular interactions of NP-ST were maintained in the ternary amorphous systems, suggesting the miscible dispersion of the co-amorphous system into the polymer via weak interactions as co-amorphous solid dispersions. The dissolution profile of co-amorphous NP-ST was 4.1- and 6.7-fold higher than that of crystalline NPs in pH 1.2 and 6.8 buffers, respectively. The drug concentration in the ternary amorphous system in pH 1.2 and 6.8 buffers became 1.1-1.2- and 1.4-2.7-fold higher than that seen in the co-amorphous system, respectively. Conclusions: Co-amorphous solid dispersion is a promising method for enhancing the solubility of brick dust molecules.

Dramatic Enhancement Enabled by Introducing TiN into Bread-like Porous Si-Carbon Anodes for High-Performance and Safe Lithium Storage.

Doping modifications and surface coatings are effective methods to slow volume dilatation and boost the conductivity in silicon (Si) anodes for lithium-ion batteries (LIBs). Herein, using low-cost ferrosilicon from industrial production as the energy storage material, a bread-like nitrogen-doped carbon shell-coated porous Si embedded with the titanium nitride (TiN) nanoparticle composite (PSi/TiN@NC) was synthesized by simple ball milling, etching, and self-assembly growth processes. Remarkably, the porous Si structure formed by etching the FeSi2 phase in ferrosilicon alloys can provide buffer space for significant volume expansion during lithiation. Highly conductive and stable TiN particles can act as stress absorption sites for Si and improve the electronic conductivity of the material. Furthermore, the nitrogen-doped porous carbon shell further helps to sustain the structural stability of the electrode material and boost the migration rate of Li-ions. Benefiting from its unique synergistic effect of components, the PSi/TiN@NC anode exhibits a reversible discharge capacity up to 1324.2 mAh g-1 with a capacity retention rate of 91.5% after 100 cycles at 0.5 A g-1 (vs fourth discharge). Simultaneously, the electrode also delivers good rate performance and a stable discharge capacity of 923.6 mAh g-1 over 300 cycles. This research can offer a potential economic strategy for the development of high-performance and inexpensive Si-based anodes for LIBs.

Microstructure and magnetic properties of surfactant-assisted ball milling NdFe8Co2Mo2 powders and their nitrides

The NdFe8Co2Mo2 alloy ribbons were prepared by melt-spinning. The powder was prepared through surfactant-assisted ball milling, followed by nitriding to produce the NdFe8Co2Mo2Nx alloy. The alloy ribbons grain size decreases as the copper roller speed increases. At the speed of 30 m/s, a pure 1:12 phase alloy ribbons were produced. The grain size decreases with increasing the ball milling time, but the composition phases almost unchanged of the alloy powder. The grain size refine after nitriding, but the grain volume expands when the nitriding temperature exceeds 500 °C. With increasing ball milling time and nitriding temperature, the remanence (Mr) and coercivity (Hc) of the alloy powder increase first and then decrease. The alloy powder obtained from ball milling for 3 h after nitriding at 475 ℃ for 3 h, resulting in Mr was 44.43 Am2/kg, Hc was 0.434 T, and saturation magnetization (Ms) was 74.89 Am2/kg.

The effect of high-energy ball milling on enhancing the mechanical properties, light transmittance, and thermal shock resistance of bone china porcelain

A bone china grouting slurry was prepared using two different milling methods: low-energy ball milling (Named LBC) for 24 h and high-energy ball milling (Named HBC) for 1 h. Bone china green bodies were formed by grouting, and the dried green bodies were calcined at different temperatures points in the temperature range from 1235 °C to 1255 °C. The slurry characteristics, as well as the structure and properties of the calcined samples, were analyzed and evaluated. The particle sizes of LBC and HBC slurry D50 are 5.819 μm and 3.571 μm, respectively, accounting for 80.4% and 98.7% of their respective proportions. The particle size distribution range of HBC samples was relatively concentrated, and the viscosity of the two slurries was 1040 mPa·s and 2800 mPa·s, respectively. The ball milling method significantly influenced the formation of product phases. The content of calcium feldspar and β-TCP phases in HBC samples calcined at 1245 °C was higher than that in their LBC counterparts, while the quartz content in LBC was higher than that in HBC samples. The water absorption and porosity of the HBC samples were lower than those of the LBC samples, with a flexural strength of 205 MPa, heat shock temperature difference of 190 °C, and light transmittance of 5.18%/3.73 mm, which were 22.4%, 26.7%, and 4.2% higher than those of the LBC samples, respectively. These results indicate that bone china prepared using the high-energy ball milling method exhibits excellent performance.

Zero-valent iron on graphite-cellulose biochar catalysts for the Fenton degradation of tetracycline from water

Tetracycline (TC), an antibiotic widely used in the treatment of animal and human diseases and promotion of animal growth. However, its uncontrolled discharge to water sources can also cause the promotion of antibiotic resistant bacteria and genes. In this study, graphite and cellulose were used as raw materials to construct a graphite-biochar (G-BC) by carbothermal reactions. This graphite-biochar was subsequently mixed with ZVI with various mass ratios by ball milling to produce graphite-biochars supported ZVI (ZVI/G-BC) catalysts, further used in the heterogeneous Fenton degradation of tetracycline. The materials were fully characterized by different techniques. The removal of TC by BC, G-BC and ZVI/G-BC was tested under different reaction conditions. The best synthesis conditions were achieved at a heating temperature of 700 °C, a graphite content of 20 %, a ball milling speed of 500 rpm, a ball milling time of 5 h, as well as a G-BC and ZVI mass ratio of 1:3. Graphite improves the conductivity and micropore area of the material, which enhances the removal of TC by ZVI/G-BC catalysts in Fenton-like reactions. TC was first oxidized to intermediate products and then further mineralized to CO2 and H2O. The best TC removal performance was obtained with a catalyst dosage of 1.1 g·L1, a hydrogen peroxide concentration of 140 mM and an initial pH value of 3. The reaction data fitted properly a pseudo first-order kinetic equation. TC removal as high as 91 % was achieved even in the 3rd round of reuse. This study reports a novel ZVI material with high conductivity and good TC removal performance.