Search Results (580)

Efficient blasting design is increasingly regarded not only as a geomechanical problem but also as a managerial challenge related to energy use, fragmentation quality, downstream comminution costs, and environmental performance. This study develops a shock-adiabat-based analytical model for predicting the radius of the crushing zone around borehole explosive charges and demonstrates its applicability as a decision support tool for energy- and cost-oriented blasting management. The model integrates shock wave propagation parameters, particle velocity behind the shock front, and the physical and mechanical properties of limestone, sandstone, and granite. The calculated crushing zone radiation was compared with a previously developed analytical model based on borehole pressure and validated using finite element simulations in SolidWorks Simulation. The discrepancy between the proposed shock adiabat model and the reference analytical solution did not exceed 6%, while the difference between analytical estimates and numerical simulations remained below 5%. The results show that borehole diameter, compressive strength, and explosive–rock interface pressure significantly affect the crushing zone radius and, consequently, the volume of rock effectively fragmented during blasting. A scenario-based assessment further indicates that improved prediction and management of the crushing zone may reduce downstream crushing and grinding energy demand by approximately 10–20%, generating potential cost savings and indirect CO₂ emission reductions. The proposed method therefore supports the management of blasting energy efficiency, fragmentation quality, operational costs, and sustainability performance in mineral extraction systems. Full article

Fine grinding is often associated with high energy consumption, and the choice of operating parameters has a direct effect on product fineness. This study examines dry particle size reduction under the two-sided impact of counter-moving grinding media. A previously developed calculation model was used to estimate the final particle size, and the calculated values were compared with experimental results obtained for quartz-rich river sand with an initial particle size of 100 μm. The study considered four parameters: horizontal amplitude, vertical amplitude, oscillation frequency, and grinding media diameter. Increasing the horizontal amplitude from 2 to 6 mm reduced the experimental product fineness from 19.6 to 4.8 μm. The vertical amplitude had a weaker effect, but increasing it from 1 to 4 mm also reduced the experimental particle size from 9.9 to 5.0 μm. An increase in frequency from 40 to 60 Hz reduced the experimental product fineness from 12.1 to 5.4 μm. The opposite tendency was observed for grinding media diameter: increasing it from 5 to 15 mm increased the experimental particle size from 4.8 to 11.4 μm. The average difference between theoretical and experimental results was 12.28%. In 12 of the 17 studied operating modes, the deviation was less than 15%. Laser particle size analysis of the selected finest sample was additionally performed to characterize the particle size distribution and fine particle fraction. The present work extends the previous model validation by evaluating the main operating variables and proposing a preliminary rational operating range for the studied dry grinding process. The results show that the model can be used for preliminary estimation of product fineness and for identifying the most influential operating parameters under the studied dry grinding conditions. Full article

Efficient separation of cocoa shell and kernel is a critical operation in semi-finished cocoa processing, where conventional mechanical methods such as grinding, cutting, and rubbing often generate excessive heat, leading to cocoa butter melting and degradation of kernel quality due to its high fat content. To overcome these limitations, this study pro-poses a dynamic impact-based framework for a small-scale centrifugal cracking system, in which fracture is induced by controlled kinetic impact rather than compressive loading. A combined theoretical and experimental investigation was conducted on roasted cocoa beans at a small industrial scale. Mechanical characterization showed that the mean and maximum shell fracture forces were 23.515 N and 54.382 N, respectively, while kernel fracture forces were significantly higher at 91.896 N and 195.327 N. A dynamic analysis of the centrifugal cracker identified a critical rotational speed range of 812–975 rpm, corresponding to impact velocities of 17.14–20.57 m/s and kinetic energies of 0.17–0.25 J per bean. Experimental validation indicated an optimal operating range of 860–900 rpm, achieving less than 1.1% uncracked beans and less than 2% fine nibs (<3 mm). Below 800 rpm, incomplete cracking was observed, whereas speeds above 950 rpm increased kernel fragmentation. These results demonstrate that precise control of impact energy is the key factor governing efficient centrifugal cracking performance in cocoa processing. Full article

This study evaluates the technical, environmental, and economic feasibility of converting plantain and banana biomass (PBB) into renewable energy in the Santa Elena province, Ecuador. Through GIS-based assessment, empirical correlations for heating value estimation, and energy/exergy analyses, our work identifies 253,389.98 tons/year of field residues with a theoretical energy potential of 382.79 GWh/year. Passive solar drying and mechanical grinding enable low-energy pre-treatment, yielding a net energy output of 12.41 MJ/kg and an exergy efficiency of 51.2%, confirming the system’s thermodynamic viability. If implemented at scale with a 20% plant factor, the energy recovered could meet 17% of the province’s current electricity demand. Economic projections estimate a potential annual revenue of USD 18.95 million based on current electricity prices, supporting the profitability of decentralized combustion systems. The integration of PBB into the regional energy matrix contributes to reducing fossil fuel reliance, enhancing energy security, and promoting sustainable rural development. These findings align with Sustainable Development Goals (SDGs) 7 and 13, positioning biomass energy as a viable solution to Ecuador’s decarbonization goals and rural energy challenges. Full article

Comminution–classification circuits are difficult to optimize because hydraulic, granulometric, energy, and economic responses are nonlinearly coupled, while circuit simulation, equipment sizing, simulator benchmarking, and operating optimization are often treated separately. This study aimed to develop an open Python framework for steady-state simulation and five-objective optimization of a rod mill–hydrocyclone–ball mill circuit processing a gold ore. The framework integrates solid and water balances, Rosin–Rammler particle-size reconstruction, comminution and hydrocyclone models, preliminary equipment sizing, explicit feasibility constraints, and Multiobjective Particle Swarm Optimization (MOPSO). Its novelty lies in coupling complete-circuit simulation, simulator-to-simulator benchmarking against USIM PAC^®, model-based sizing, convergence diagnostics, and Pareto optimization within one transparent workflow. The benchmark produced zero or below ${10}^{-3}\%$ errors in solid balances and sizing differences of 1.07%, 8.21%, and 0.00% for the rod mill, ball mill, and hydrocyclone, respectively. Relative to the base case, the joint minimum-water, minimum-energy, and minimum-cost solution reduced specific water consumption by 24.50%, specific grinding energy by 4.24%, specific operating cost by 10.19%, and mass recirculation by 8.80%, while useful recovery decreased slightly from 82.67% to 81.78%. The maximum-recovery solution increased useful recovery to 84.45%, with higher water, energy, and operating-cost requirements. The framework supports reproducible evaluation of resource–recovery trade-offs in grinding–classification circuits. Full article

The solid-state landscape of pharmaceutical compounds is often characterized by the occurrence of polymorphs, hydrates, and solvates, which may significantly influence their physicochemical and biopharmaceutical properties. In contrast, some active pharmaceutical ingredients exhibit a remarkable resistance to crystal form diversification, despite extensive experimental investigation. In the present work, vinpocetine was subjected to an extensive solid-form screening campaign aimed at exploring its propensity to generate alternative polymorphs, hydrates, and solvates. Mechanochemical experiments were performed under neat grinding and liquid-assisted grinding conditions using a broad range of organic solvents and water, including two-step milling procedures and formulations containing surfactants. Additional investigations included high-energy planetary milling, high-pressure compaction, exposure to controlled humidity, thermal cycling, slurry-bridging experiments in various media, and crystallization after mechanochemical neutralization of vinpocetine salts. The resulting solids were systematically characterized by powder X-ray diffraction, and thermal and morphological analyses. In all cases, the recovered solid corresponded to the commercially available crystalline form of vinpocetine, with no evidence of alternative polymorphs, solvates, or hydrates. These results demonstrate the unusual robustness of vinpocetine crystal structure across a wide range of mechanical, thermal, and solvent-mediated conditions. Notably, this behavior contrasts with the well-established ability of vinpocetine to form numerous salts and salt cocrystals, suggesting that solid-state diversification in this compound is primarily driven by proton-transfer processes rather than by neutral polymorphism or solvent incorporation. The present study provides experimentally defined boundaries for the solid-state landscape of vinpocetine and contributes valuable data for future crystal-form prediction and pharmaceutical development studies. Beyond the specific findings reported herein, the systematic documentation of both successful and unsuccessful experimental outcomes represents a valuable source of experimentally validated positive and negative data that may support the future development and validation of AI-assisted crystal-form prediction tools. Full article

The cement industry, responsible for 26% of industrial CO₂ emissions and 8% of global emissions, is under growing pressure to reduce its environmental footprint while maintaining profitability. In this context, optimizing grinding processes is essential to enhance both the efficiency and sustainability of cement production. This study presents the development of a self-adaptive expert system for closed-loop control, integrating symbolic Artificial Intelligence (AI) and Advanced Process Control (APC) techniques. The system dynamically adjusts operational parameters in real time to minimize the specific energy consumption of cement grinding while meeting quality targets. Notably, it enables autonomous plant operation without direct human supervision, thereby reallocating personnel to higher-value tasks and maintaining optimal performance continuously. The benefits observed following industrial implementation are discussed, alongside an analysis of the key factors influencing grinding performance and productivity. Furthermore, the integration of Artificial Neural Networks (ANNs) and genetic algorithms is proposed as a future enhancement, complementing the expert system through neuro-symbolic approaches. This fusion represents a significant step toward the digital transformation of industrial operations. Full article

Relatively low-cost titanium carbide (TiC) materials and metal matrix composites (MMC) are proposed for waste-to-hydrogen conversion. Two types of steels are used as bases prepared from EN 10088 flat products, namely X2CrTi12 (1.4512, AISI 409) and X5CrNi18-10 (1.4301, AISI 304). TiC is mixed with TRIBALOY^® T-800 alloy in powder form and applied via laser-directed energy deposition (DED-LB) over the substrates. For the powder mixture, Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC) are performed. The raw materials are investigated for the processes that occur in them under heating. After the solidification of the molten mixture, grinding and polishing are performed to achieve a thin layer. The studies of the obtained MMC include interface zone assessment, hardness and Young’s modulus distribution, microstructural analysis, and visual defect evaluation. Advanced sensors for acoustic emission (AE) and Electrical Contact Resistance (ECR) provided characterization together with micro-scratch testing. The use of photoluminescence spectroscopy is proposed for the new composite materials. The electron transfer pathway can be studied with time-resolved spectroscopy. Renewable energy production by breaking down waste into hydrogen-rich syngas can be achieved through pyrolysis, followed by steam reforming and purification. The obtained novel materials show promising application solutions with increased durability, corrosion, and wear resistance. Full article

Industrial chili peppers are specialized varieties primarily used for the extraction of capsaicinoids and paprika red. Their post-harvest processing level directly affects product quality and industrial economic benefits. Most existing studies have focused on a single unit operation or on edible chili peppers, and a systematic review of the entire post-harvest processing chain for industrial chili peppers is still lacking. Taking the standardized post-harvest processing workflow of industrial chili peppers as its core theme, this paper systematically reviews the current research approaches and application status of industrial chili pepper post-harvest processing technologies across six core unit operations, namely cleaning and impurity removal, grading and sorting, drying, stem and seed removal, crushing and grinding, and extraction of bioactive compounds. The analysis indicates that the field currently faces four common challenges: the lack of standardized processing parameters for classified processing, relatively low drying energy efficiency, insufficient online sensing and intelligent collaborative control, and a scarcity of industrial-scale validation for emerging technologies. This paper further constructs a technical route and technology evaluation framework for the entire post-harvest processing chain of industrial chili peppers, clarifies the applicable boundaries and scale suitability of different processing technologies, and provides a theoretical basis for industrial technological upgrading and process selection. Full article

Lithium-ion batteries are widely used in digital, power and energy storage fields due to their high capacity and high cycle life advantages. This paper systematically screens the formulation system and designs a high-efficiency production line that can effectively improve production efficiency, reduce production costs, and lower energy consumption per unit product. The produced nano-silicon-enhanced graphite anode material has excellent performance. The selection of silicon raw materials, types of solvents, types of dispersants, and grinding processes is studied to investigate the influence of these four factors on the wet grinding process for preparing nano-silicon. Finally, metal silicon obtained by air flow pulverization is selected as the raw material, isopropanol is used as the solvent, FA01 (carboxylic acid type) is used as the dispersant, and a two-stage wet grinding process is adopted to prepare the nano-silicon dispersion solution. Zirconia beads of 0.5 mm and 0.2 mm size are used as the grinding media for the first and second stages, respectively, with filling rates of 80% and 90%, respectively. The final prepared nano-silicon dispersion is stable in dispersion and has a narrow particle size distribution. The nano-silicon dispersion solution and the multi-walled carbon nanotube dispersion solution are mechanically ground and mixed using a sand mill. At the same time, the multi-walled carbon nanotubes are coated with the nano-silicon. Then, artificial graphite is added for compounding. Finally, through spray drying, the Si@MWCNTs@graphite (SMG) nano-silicon-enhanced graphite negative electrode material is prepared. The SMG nano-silicon-enhanced graphite negative electrode material with a silicon content of 2% has a first Coulomb efficiency of up to 84.32%. Full article

This study presents the development of a combined heating system for a bioreactor designed to improve the efficiency of organic waste biodegradation. The proposed system maintains the required operating temperature within a specified range without relying on external energy sources, thereby enhancing the sustainability and energy efficiency of the bioconversion process. A bioreactor heating system based on a “water jacket” that is heated by the combustion of coal–water fuel has been developed. The “water jacket” is a system of two 15 mm diameter tubes located along a cylindrical axis inside the bioreactor. Heated liquid flows through the tubes, accelerating biomass fermentation processes. A technology for preparing and burning coal–water fuel using a radial circulation injection device is offered. Calculations are performed to determine the optimal temperature regime for the combustion process. Optimal conditions for electric pulse coal grinding (28 kV, 600 discharges) were established, the required particle size distribution of 50–250 µm was achieved, and the ignition temperature of the coal–water mixture (650 °C) was determined. The findings may contribute to improved waste management technologies and environmental sustainability by reducing carbon emissions and waste generation. Full article

Wet grinding is an important operation in the technological process of ceramic tile production. The properties of the slurry obtained from grinding (slip) are conditioned by the raw materials (the type and characteristics of raw material in mixture, recipes for mixture), and by the operating parameters in grinding (technical characteristics of mill, type of grinding system, mill charge, grinding media body, grinding time, etc.). The optimal selection of these influential parameters results in satisfactory properties of slip, i.e., in efficient grinding as process operation, and, consequently, in smooth and efficient realisation of subsequent operations in the process, particularly spray drying. At the end of the technological process, the final goal is to obtain a ceramic tile of satisfactory quality. Multi-criteria decision-making (MCDM) is an increasingly applied tool for selecting optimal technological parameters for the purpose of optimisation, problem solving and improvement of technological processes. This paper presents the application of the symmetry point of criterion—ranking alternatives by perimeter similarity (SPC-RAPS) as an MCDM hybrid method for the selection of optimal technological parameters in grinding in the ceramic tile production process. The ranking and selection of alternatives (raw materials, grinding balls and grinding time) were performed according to various criteria. In addition to the technological parameters related to the characteristics of the products from the grinding (slip), and to the technical characteristics of the final product (ceramic tiles), the criteria also included economic parameters (the market price of raw material and specific energy consumption in grinding). The developed mathematical model enabled the selection of the best alternative as a solution for this problem. Full article

Although CFM is a promising non-thermal stabilization technology for blackberry juice, its industrial application is limited by permeate flux decline during long-term operation, while most previous studies have focused on short processing times. This study evaluated the effect of high-shear homogenization prior to enzymatic depectination on flux decline, product quality, and techno-economic feasibility during CFM. Juice processed by conventional grinding, high-shear homogenization, and enzymatic treatment was filtered through a 0.2-µm ceramic membrane at 150 kPa using feed volumes of 100–400 L. Homogenization reduced particle size and suspended insoluble solids, resulting in higher permeate flux, improved flux stability, and greater productivity. Flux decline analysis showed that high-shear homogenization extended the stable filtration regime and delayed severe fouling, sustaining an average J_px of 65.3 L h⁻¹ m⁻² at VCR ~30 with feed volumes up to 400 L. Product quality was preserved, ensuring microbial reduction while improving anthocyanin and ellagitannin recovery (95% and 80%, respectively) and enhancing blackberry aroma. In addition, HS3+E reduced energy consumption and beverage production cost while achieving a positive NPV and a 21% IRR. Overall, homogenization improved the industrial feasibility of long-term CFM processing of Andean blackberry juice. Full article

Conventional valorization of blast furnace slag commonly involves granulation, fine grinding, mechanical activation, or chemical activation, which increase energy demand and processing complexity. This study investigated a minimally processed blast furnace slag (MP-BFS), defined here as the fraction passing 64 µm obtained by sieving a 0–8 mm industrial material without grinding, additional granulation, thermal treatment, or chemical activation. MP-BFS replaced 10–50% of the cement by mass to reduce clinker in industrial mortars formulated at a constant flow spread of 23–24 cm and tested from 8 h to 90 d. Bulk density, water-accessible porosity, total and capillary water absorption, and compressive and flexural strengths were evaluated. Replacing 10% of the cement with slag improved compressive strength from the earliest test age and increased the 28-day compressive and flexural strengths by 5.1% and 9.5%, respectively, relative to the control mortar; this response coincided with a reduction in measured porosity from 8.95% to 8.01%. This improvement is consistent with a physical filling effect and improved particle packing, although these mechanisms were not directly verified by microstructural analyses. At higher replacement levels, water-accessible porosity increased, reaching 24.45% at 50% slag replacement, alongside greater water ingress and delayed strength development. Exploratory empirical regression analyses described associations among slag content, porosity, water transfer, and compressive strength within the investigated formulations. A simplified screening-level constituent-production-and-transport comparison per cubic meter, based on generic ICE factors and an assumed 50 km transport distance, estimated a maximum embodied carbon reduction of 44% at 50% replacement. Curing energy, use, carbonation, maintenance, and end-of-life stages were excluded. Overall, 10% MP-BFS replacement provided the most favorable performance–carbon content balance, whereas 30–50% achieved larger carbon reductions but showed early-age strength losses that limit their suitability for rapid-demolding applications under the investigated conditions. Full article

The global proliferation of plastic waste has made the search for sustainable chemical recycling strategies imperative to transition toward a circular bioeconomy. This study presents a dual-valorization approach for polylactic acid (PLA) waste, utilizing it both as a sustainable precursor for g-C₃N₄ catalyst synthesis and as a sacrificial agent for green hydrogen production via photoreforming. Platinum-modified graphitic carbon nitride catalysts were synthesized and evaluated using pure lactic acid and commercial PLA waste under solar-simulated irradiation. Results identified C₃N₄-NaOH-Pt as the most active material, while the simultaneous one-pot depolymerization/photoreforming of macroscopic PLA fragments exhibited a peak H₂ production rate of 1.5 mmol·h⁻¹·g⁻¹, remarkably surpassing both the pure monomer model and pre-depolymerized solutions. This enhanced performance is tentatively attributed to a “controlled release” mechanism that prevents catalyst surface saturation and minimizes light scattering effects inherent to fine powders. The study concludes that maintaining the macroscopic integrity of PLA waste provides a strategic advantage for chemical reforming by eliminating energy-intensive grinding and pretreatment. Future research into diverse operational and chemical parameters, including temperature and base-addition strategies, will be essential for scaling solar-driven upcycling technologies. Full article