Optimal Particle Size Distribution Research Articles

3-D visual analysis and quantitative characterization on coal matrix based on Micro-CT

Coal matrix, the storage space for adsorbed gas, is highly related to gas recovery and gas outburst disasters. However, existing research predominantly relies on theoretical assumptions, lacking experimental validation. In this study, we employ X-ray computed tomography (CT) to obtain high-resolution (13.45–15.157 μm) internal structure images of various coal samples. The three-dimensional model of coal matrix elements is reconstructed using entropy threshold segmentation and watershed segmentation. A systematic quantification of the size, shape, and spatial arrangement of these matrix elements is then performed. The results reveal that coal matrix element equivalent diameters span 148.45–2800.35 μm, with volume-weighted average equivalent diameters ranging from 1320.82 to 1720.87 μm. Additionally, we explore particle size distribution (PSD) models to characterize size-quantity relationships and identify the Jaky model based on the logarithmic-exponential equation as the optimal PSD model. Observation of the matrix element models shows that large matrix elements typically exhibit flattened morphologies with rough surfaces, while smaller ones tend to be blocky with smooth surfaces. The dimensionless shape factor results suggest that, when scale effects are not considered, the shape of larger matrix elements is more conducive to matrix-fracture gas mass transfer. Based on this, a functional relationship between the matrix shape factor and size, considering changes in matrix morphology, is established. Moreover, we algorithmically determine that the average number of adjacent matrix elements per individual matrix element falls between 13 and 15. For matrix clusters with large volume fractions, the size ratio of the central matrix element to adjacent matrix elements primarily falls within the range of 0.4–0.6, approximately following a Weibull distribution. According to this feature, a method for building a matrix cluster model used for simulations is proposed.

A remote sensing algorithm for vertically resolved cloud condensation nuclei number concentrations from airborne and spaceborne lidar observations

Abstract. Cloud condensation nuclei (CCN) are mediators of aerosol–cloud interactions (ACIs), contributing to the largest uncertainties in the understandings of global climate change. We present a novel remote-sensing-based algorithm that quantifies the vertically resolved CCN number concentrations (NCCN) using aerosol optical properties measured by a multiwavelength lidar. The algorithm considers five distinct aerosol subtypes with bimodal size distributions. The inversion used the lookup tables developed in this study, based on the observations from the Aerosol Robotic Network, to efficiently retrieve optimal particle size distributions from lidar measurements. The method derives dry aerosol optical properties by implementing hygroscopic enhancement factors in lidar measurements. The retrieved optically equivalent particle size distributions and aerosol-type-dependent particle composition are utilized to calculate critical diameters using κ-Köhler theory and NCCN at six supersaturations ranging from 0.07 % to 1.0 %. Sensitivity analyses indicate that uncertainties in extinction coefficients and relative humidity greatly influence the retrieval error in NCCN. The potential of this algorithm is further evaluated by retrieving NCCN using airborne lidar from the NASA ObseRvations of Aerosols above CLouds and their intEractionS (ORACLES) campaign and is validated against simultaneous measurements from the CCN counter. The independent validation with robust correlation demonstrates promising results. Furthermore, the NCCN has been retrieved for the first time using a proposed algorithm from spaceborne lidar – Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) – measurements. The application of this new capability demonstrates the potential for constructing a 3D CCN climatology at a global scale, which helps to better quantify ACI effects and thus reduce the uncertainty in aerosol climate forcing.

Preparation and performance of solid thermal energy storage materials based on low-grade pyrophyllite minerals

The new sensible thermal energy storage materials were prepared by the sintering method with low-grade pyrophyllite mineral powders as main raw materials, Suzhou clay as the sintering aid and sulfite liquors as the binder. Further, the performance of sensible thermal energy storage under different size distributions and sintering temperatures was investigated and analyzed. The results show that the optimum particle size distribution is 50:15:35, the bulk density, thermal conductivity, and specific heat capacity are the largest values, which are 1.97 g cm−3, 0.87 W m−1 K−1 and 0.63 kJ kg−1 K−1, respectively. Other properties including porosity, water absorption, flexural and compressive strength and so on are optimal under this size distribution. When the sintering temperature is 1200 °C, the material has a good thermal conductivity of 0.89 W m−1 K−1 and a high bulk density of 2.05 g cm−3. Meanwhile, the sample with the used temperature from 50 to 900 °C has the best thermal energy storage capacity of 306.29 kWh·m−3.

Order-disorder transition during shear thickening in bidisperse dense suspensions

Shear thickening of multimodal suspensions has proven difficult to understand because the rheology depends largely on the microscopic details of stress-induced frictional contacts at different particle size distributions (PSDs). Our discrete particle simulations below a critical volume fraction ϕc over a broad range of shear rates and PSDs elucidate the basic mechanism of order–disorder transition. Around the theoretical optimal PSD (relative content of small particles ζ1= 0.26), particles order into a layered structure in the Newtonian regime. At the onset of shear thickening, this layered structure transforms to a disordered one, accompanied by an abrupt viscosity jump. Minor increase in large-large particle contacts after the order–disorder transition causes apparent increase in radial force along the compressional axis. Bidisperse suspensions with less regular but stable layered structure at ζ1= 0.50 show good fluidity in the shear thickening regime. This work shows that in inertial flows where particle collisions dominate, order–disorder transition could play an essential role in shear thickening for bidisperse suspensions.

Development of long-acting injectable suspensions by continuous antisolvent crystallization: An integrated bottom-up process

Our present work elucidated the operational feasibility of direct generation and stabilization of long-acting injectable (LAI) suspensions of a practically insoluble drug, itraconazole (ITZ), by combining continuous liquid antisolvent crystallization with downstream processing (i.e., centrifugal filtration and reconstitution). A novel microchannel reactor-based bottom-up crystallization setup was assembled and optimized for the continuous production of micro-suspension. Based upon the solvent screening and solubility study, N-methyl pyrrolidone (NMP) was selected as the optimal solvent and an impinging jet Y-shaped microchannel reactor (MCR) was selected as the fluidic device to provide a reproducible homogenous mixing environment. Operating parameters such as solvent to antisolvent ratio (S/AS), total jet liquid flow rates (TFRs), ITZ feed solution concentration and the maturation time in spiral tubing were tailored to 1:9 v/v, 50 mL/min, 10 g/100 g solution, and 96 h, respectively. Vitamin E TPGS (0.5% w/w) was found to be the most suitable excipient to stabilize ITZ particles amongst 14 commonly used stabilizers screened. The effect of scaling up from 25 mL to 15 L was evaluated effectively with in situ monitoring of particle size distribution (PSD) and solid-state form. Thereafter, the suspension was subjected to centrifugal filtration to remove excess solvent and increase ITZ solid fraction. As an alternative, an even more concentrated wet pellet was reconstituted with an aqueous solution of 0.5% w/w Vitamin E TPGS as resuspending agent. The ITZ LAI suspension (of 300 mg/mL solid concentration) has the optimal PSD with a D10 of 1.1 ± 0.3 µm, a D50 of 3.53 ± 0.4 µm and a D90 of 6.5 ± 0.8 µm, corroborated by scanning electron microscopy (SEM), as remained stable after 548 days of storage at 25 °C. Finally, in vitro release methods using Dialyzer, dialysis membrane sac were investigated for evaluation of dissolution of ITZ LAI suspensions. The framework presented in this manuscript provides a useful guidance for development of LAI suspensions by an integrated bottom-up approach using ITZ as model API.

Particle Size Distributions and Extinction Coefficients of Aerosol Particles in Land Battlefield Environments

In land battlefield environments, aerosol particles can cause laser beams to undergo attenuation, thus deteriorating the operational performance of military laser devices. The particle size distribution (PSD) and extinction coefficient are key optical properties for assessing the attenuation characteristics of laser beams caused by aerosol particles. In this study, we employed the laser diffraction method to measure the PSDs of graphite smoke screen, copper powder smoke screen, iron powder smoke screen, ground dust, and soil explosion dust. We evaluated the goodness of fit of six common unimodal PSD functions and a bimodal lognormal PSD function employed for fitting these aerosol particles using the root mean square error (RMSE) and adjusted R2, and selected the optimal PSD function to evaluate their extinction coefficients in the laser wavelength range of 0.249~12 μm. The results showed that smoke screens, ground dust, and soil explosion dust exhibited particle size ranges of 0.7~50 µm, 1~400 µm, and 1.7~800 μm, respectively. The lognormal distribution had the best goodness of fit for fitting the PSDs of these aerosol particles in the six unimodal PSD functions, followed by the gamma and Rosin–Rammler distributions. For the bimodal aerosol particles with a lower span, the bimodal lognormal PSD functions exhibited the best goodness of fit. The graphite smoke screen exhibited the highest extinction coefficient, followed by the copper and iron powder smoke screens. In contrast, the ground dust and soil explosion dust exhibited the lowest extinction coefficients, reaching their minimum values at a wavelength of approximately 8.2 μm. This study provides a basis for analyzing and improving the detection and recognition performance of lasers in land battlefield environments.

Effects of fragmentation on production at Peak mine Midlands, Zimbabwe

Over the years, the cost of production at Peak Mine Midlands, Zimbabwe, has been high due to oversized rock fragments. This led to increased mining costs far above what was planned by the mine. Initial investigations showed that valuable production hours were lost in trying to deal with the oversized rock fragments at the draw points. This study was conducted at Peak Mine Midlands, Zimbabwe, on 1210 level. The methods used to assess the effects of fragmentation on production at the mine included visual assessment, analysis of the drill and blasting costs of the production data, 2D image analysis, sieve analysis, time and motion studies, analysis of the explosive’s consumption, mining blasting trials and post-mine blast experiments. The results show that the current ring hole designs used in the sublevel open stopes at Peak Mine do not give optimal particle size distribution after the primary blasts as the sieve analyses show that 50% of the sizes of materials at the draw points are larger than 1,000 mm. While 4 secondary blasts were budgeted per shift to reduce the sizes of the boulders to sizes that will pass through the grizzly’s sieves, 7 secondary blasts were done per shift and this led to about 75% increase in the cost of explosives consumed by the mine. The results also show that 35.96 minutes of production time were lost on each secondary blast conducted. Four trial blasts conducted on different ring hole patterns show that ring #1 which has a burden of 1.2 m instead of 1.8 m in the other ring holes led to a significant reduction in drilling and blasting costs from USD $33.79 in trial #4 (the control case) to $28.80 in trial #1. The sieve analyses also show that the optimal fragment sizes from primary blasts are in the range of X = +200 mm and X = +300 mm. So, the designed ring hole patterns in the sublevel open stopes should produce particles with sizes in the range of  150 mm and  +350 mm from the primary blasts.

Investigation of heat transfer processes in multi-sized solar-sintered regolith for lunar ISRU program

Effective Thermal Conductivity (ETC) prediction of sintered lunar regolith plays a crucial role in developing extraterrestrial thermal processing and construction techniques for In-situ Resource Utilization (ISRU) projects on the Moon. Most existing literature has been focused on the packed lunar regolith without considering the sintering mechanism. Herein, we presented a mechanistic model to estimate the ETC of sintered lunar regolith. The Monte-Carlo method was applied to simulate the thermal neck resistance between multi-scaled particles, while the irregular particle geometry was characterized by shape factors. The presented model was experimentally validated by the measured ETC and specific surface area of fabricated lunar simulant samples LMS-1 with various granularities sintered under air, argon gas and low vacuum (10−3 Pa). Furthermore, the heat transfer process within solar sintered LMS-1 bed was simulated coupled with the ETC model. Transient behaviors of microstructure, thermal conductivity and temperature profile during solar heating were simulated iteratively. The simulated temperature profiles at the steady state concur well with measured data obtained from the solar sinter testing with an average Root Mean Squared Error (RMSE) of 5.5%, which performs better than the un-sintered ETC model (RMSE=12.7%). The measured sintered depth was improved by 45% with an optimized particle size distribution (PSD) arrangement.

Enhancing the flowability of limestone water suspension for economical transportation by variation in particle size distribution

Hydrotransport is increasingly a popular technology due to its low specific energy consumption and nonpolluting nature. The current work presents a thorough characterization of a limestone sample to explore the influence of blending medium and coarse particles with fine particulate slurry on the rheology, slurryability, and stability of a limestone water suspension. Various bench-scale studies are performed to identify the physicochemical, morphological, and flow features of limestone samples. Eight separate bi-modal slurry samples are prepared using limestone materials with three unique particle size ranges (53, 53–75, and 75–106 µm). The rheological properties of the slurry are tested at shear rates ranging from 50 to 500 1/s, and regression analysis is used to determine the nature of the slurry. The solid concentration of the suspension sample ranges between 10 and 70% with a flow velocity range of 0.25–1.5 m/s through a 100 mm diameter pipeline. Finally, essential criteria such as apparent viscosity, settling properties, pressure drop, and specific energy consumption are used to determine the optimal particle size distribution. The ideal proportion of medium particles (53–75 µm) mixing in the fine particulate slurry suspension is 40%, while the fraction of coarse particles (75–106 µm) is 30% (by weight).

Model-based optimization of drug release rate from a size distributed population of biodegradable polymer carriers

In the present study, a comprehensive polymer degradation-drug diffusion model is developed to describe the polymer degradation kinetics and quantify the release rate of an active pharmaceutical ingredient (API) from a size-distributed population of drug-loaded poly(lactic-co-glycolic) acid (PLGA) carriers in terms of material and morphological properties of the drug carriers. To take into account the spatial–temporal variation of the drug and water diffusion coefficients, three new correlations are developed in terms of spatial–temporal variation of the molecular weight of the degrading polymer chains. The first one relates the diffusion coefficients with the time-spatial variation of the molecular weight of PLGA and initial drug loading and, the second one with the initial particle size, and the third one with evolution of the particle porosity due to polymer degradation. The derived model, comprising a system of partial differential and algebraic equations, is numerically solved using the method of lines and validated against published experimental data on the drug release rate from a size distributed population of piroxicam-PLGA microspheres. Finally, a multi-parametric optimization problem is formulated to calculate the optimal particle size and drug loading distributions of drug-loaded PLGA carriers to realize a desired zero-order drug release rate of a therapeutic drug over a specified administration period of several weeks. It is envisaged that the proposed model-based optimization approach will aid the optimal design of new controlled drug delivery systems and, consequently, the therapeutic outcome of an administered drug.

Recyclability of low-density polyethylene water sachet film into powder and its suitability for polyethylene-wood composite

Low density polyethylene (LDPE) based water sachet films were recycled into polymer powder by thermochemical treatment. Varying weights of sachet films were dissolved in automotive gas oil (AGO) at elevated temperature, followed by quenching in an ice-bath stainless steel container to determine optimum powder yield and particle size distribution. Sieve analysis of powder was carried out into different particle sizes and consequently to eliminate lumps. The polymer powder was subsequently mixed with maleic anhydride treated African mahogany wood dust (WD), in ratios 80:20, 70:30 and 60:40 wt%, and compacted by hot pressing to produce composite samples. Performance evaluation was carried out on the composite using tensile, flexural and impact energy testing techniques. Water absorption test was also carried out to determine hydrophilicity of the composite. The mass of powder yield from thermochemical treatment was about twice the amount of sachet films. Film dissolution of 100 mg/L of AGO gave optimal powder yield and size distribution with minimal lumps. Performance tests showed that, tensile and flexural strength, and impact energy of composites decreased with increase in the weight percent of wood dust. The water absorption test also revealed increased hydrophilicity of the composite with wood dust ratio.

Particle Engineering for Customized Drug Particles and its Applications

Particle engineering is a technique that involves the customization of particles in order to get desired properties of the pharmaceutical products. The use of particle engineering is in obtaining optimum particle size and particle size distribution and getting particles of desired size. The other aspects of the particle engineering involves the morphological changes of the drug substances. The particle engineering involves improvement of physicochemical properties such as solubility, stability, improved bioavailability and formulation of novel drug delivery systems such as pulmonary drug delivery system. This article includes various techniques used for the particle engineering such as Micronization, Spray drying, high pressure homogenization, Supercritical fluid technology and freeze drying. Article also covers the different uses of particle engineering in pharmaceutical industry.

Transparent diamond ceramics from diamond powder

Diamond possesses a unique combination of excellent optical, thermal, and mechanical properties, and is therefore an ideal transparent ceramic material for harsh and extreme environments. Due to its important applications in technology, transparent diamond ceramic (TDC) has been explored and prepared by chemical vapor deposition (CVD) or direct conversions of non-diamond carbon precursors at high pressure and high temperature (HPHT), but the preparation of large-size TDC with high mechanical strength remains a challenge. Here, we report for the first time, a transparent polycrystalline diamond ceramic from diamond powder with a transmittance of ∼60 % at wavelengths of 400–1600 nm. The analyses of phase composition, residual stress and microstructure evolution of the sintered samples with different sintering conditions indicate that compression at high temperatures (>2000 ⁰C) facilitates the deformation of diamond grains, allowing for densification and diamond-diamond bonding formation. The sintering pressure of the diamond powders with an optimized particle size distribution was dramatically reduced from 16 GPa to 10 GPa. Our results, based on successfully preparing centimeter-sized TDC, set the standard and the precedent for the large-scale preparation of larger TDC in proximity to industrial conditions.

Size controllable single-crystalline Ni-rich cathodes for high-energy lithium-ion batteries.

A single-crystalline Ni-rich (SCNR) cathode with a large particle size can achieve higher energy density, and is safer, than polycrystalline counterparts. However, synthesizing large SCNR cathodes (>5μm) without compromising electrochemical performance is very challenging due to the incompatibility between Ni-rich cathodes and high temperature calcination. Herein, we introduce Vegard's Slope as a guide for rationally selecting sintering aids, and we successfully synthesize size-controlled SCNR cathodes, the largest of which can be up to 10μm. Comprehensive theoretical calculation and experimental characterization show that sintering aids continuously migrate to the particle surface, suppress sublattice oxygen release and reduce the surface energy of the typically exposed facets, which promotes grain boundary migration and elevates calcination critical temperature. The dense SCNR cathodes, fabricated by packing of different-sized SCNR cathode particles, achieve a highest electrode press density of 3.9g cm-3 and a highest volumetric energy density of 3000Wh L-1. The pouch cell demonstrates a high energy density of 303Wh kg-1, 730Wh L-1 and 76% capacity retention after 1200 cycles. SCNR cathodes with an optimized particle size distribution can meet the requirements for both electric vehicles and portable devices. Furthermore, the principle for controlling the growth of SCNR particles can be widely applied when synthesizing other materials for Li-ion, Na-ion and K-ion batteries.

Determining concrete properties for different optimized combined concrete mixtures: Novel mathematical approach

Gradation of the granular skeleton significantly influences almost all of the concrete performances. The main purpose of this research work is to develop a mathematical model to characterize the properties of various dry concrete mixtures. The starting point of this work is to propose a single equation to describe continuous aggregate gradations, by combining several ideal grading curves used to design different concrete mixtures, to achieve higher freedom in optimizing the particle-size distribution (PSD) of a concrete mixture. At the design procedure stage, the concrete constituents are selected so that the overall grading of the mix closely follows a given ideal grading curve for specific properties. Using the gradation equation afore-mentioned, a mathematical framework is established to outline several intrinsic factors in the optimized granular skeleton of concrete, characterized by a wide range of particle sizes. The factors developed, directly measured based on the PSD, include the specific surface area and the fineness modulus of the combined grading of the concrete mix particles, as well as the ratio between the granular fractions determined either by area or by weight, and the surface area of the total concrete mixture. The resulting model expressions relate the characteristics of the size distribution of the concrete skeleton, to the parameters in the proposed gradation equation, in particular the distribution exponent. The proposed model could be implemented in the study of the solid phase of concrete, design aggregate gradation to meet certain requirements, or even predict some attributes of the dry concrete mixture. • A unified equation of well-known optimal particle size distributions is developed. • A model is proposed to accurately calculate some properties of the concrete mixes. • The distribution exponent in the proposed equation is the most relevant parameter. • Optimal PSDs are fractal and converge mathematically to the Fung & Dinger model. • The proposed model is suitable for systems with a wide range of particle sizes.

Determination of granulometric composition of technogenic raw materials for producing composite fuel

Purpose. To determine the granulometric composition of technogenic raw materials for agglomeration by the adhesive-chemical method. This approach allows for determining the optimal particle size distribution for obtaining the prepared agglomerated fuel, which has the form of cylindrical rods with a diameter of 30 mm and a length of 50200 mm. Methodology. The granulometric composition of technogenic raw materials was determined using sieve and sedimentation analyses. 38 representative samples of carbon-containing raw materials were subjected to the investigation. Findings. The sieve analysis results of representative samples of coal sludge and culms are presented; their graphical characteristics is given. Sieve analysis of the granulometric composition of samples of carbon-containing raw materials and sedimentation analysis of solid fuel samples with a fraction of fewer than 50 microns is carried out. It has been established that all samples with sizes of more than 56 mm should be subjected to further grinding. Originality. For the first time, studies and comparative analysis of granulometric compositions of technogenic raw materials have been realized, which allows for a reasonable approach to obtaining composite fuel from carbon-containing wastes by the adhesive-chemical method, using various compositions of components. Practical value. The results can process technogenic raw materials to get agglomerated fuel of specified parameters by the adhesive-chemical method and other processing areas, including using carbon-containing waste from various productions.

Influence of freeze–thaw cycling on properties of cementitious systems doped with fly ash having optimized particle size distribution

Influence of freeze–thaw cycling on properties of cementitious systems doped with fly ash having optimized particle size distribution

Diagnosing trace metals contamination in ageing stormwater constructed wetlands by portable X-ray Fluorescence Analyzer (pXRF)

In the context of stormwater management in urban areas, more knowledge is needed about sustainable urban drainage systems (SUDS)' long-term performance. This article reports robust calibration of a portable X-ray Fluorescence Analyzer (pXRF) for a purpose of metal accumulation diagnosis in two stormwater constructed wetlands (SCWs). Two 9-year-old SCWs located in Eastern France and composed of a sedimentation pond and a vertical-flow reed-bed filter (RBF#1) respectively a horizontal-flow RBF (RBF#2) are studied. A focus is made on the RBFs where five target metals (Cr, Cu, Ni, Pb, Zn) are monitored to fulfill three objectives: i) develop a robust analyzing method for both field and laboratory scale; ii) compute a distribution mapping of the metals on the substrate; and iii) identify and quantify contamination hotspots. pXRF measurements present an opportunity for a quick field diagnosis of such ageing systems once calibrated. An optimal 63 s beam shooting time was selected for analyses, and optimal particle size distribution was set below 250 μm. As water content is known to be a critical factor influencing measuring quality, correction factors were determined to allow for field campaign up to 30 % of water content. Metals are more accumulated in RBF#1 than in RBF#2 because of the particle size distribution and hydraulic regime of the RBFs. Moreover, RBF#1 displays a higher metal accumulation at the water supply outputs while the distribution pattern in RBF#2 is more diffuse. Only 34 %, resp. 22 % of RBF#1 and RBF#2 surface is contaminated, with corresponding concentrations ranging among the highest 50 % and 25 % concentrations. Eventually, the RBF#1 upper layer (0–5 cm) higher organic matter content generates more metal retention than its deeper layer whereas in RBF#2 metal concentration is homogeneous along depth. These results can be useful to optimize the long-term maintenance and possibly the sizing of such systems.

Selection of the particle size distribution of granular lost circulation materials for use in naturally fractured thief zones

Granular lost circulation materials (LCMs) are used to control fluid loss in naturally fractured thief zones. Rapid and automated identification of their optimal particle size distribution (PSD) is highly desirable. This paper proposes a PSD selection method for LCMs based on a PSD representation algorithm and the Monte Carlo method. The PSD representation algorithm describes the cumulative and compositional PSD curves of LCMs according to a piecewise cubic Hermite interpolation algorithm. Comparison with measured PSD data shows that the representation algorithm is more accurate than other commonly used PSD models in describing both homogeneous and mixed LCMs, and the relative errors are all within 10%. The Monte Carlo method is adopted to simulate LCMs with various compositions and select ones with PSDs that meet a proposed selection criterion. Experiments show that the PSD curves of the LCMs were all within the upper and lower bounds specified by the selection criterion. Plugging experiments show that LCMs with the recommended compositions can effectively enter fractures, and the fluid loss is less than 200 mL for half an hour under the pressure difference of 7 MPa. The proposed selection method can be used for the rapid and automatic design of granular LCMs used in fractured thief zones.

A New Method for Designing the Bridging Particle Size Distribution for Fractured Carbonate Reservoirs

Summary Possessing a strong heterogeneity of fracture space; fractures, in carbonate reservoirs are well developed. Because of the frequent occurrence of lost circulation during the drilling procedure, the matching of the particle-size distribution (PSD), which is the plugging material with the fracture space, becomes the key to forming bridges and improving plugging capacity. To improve the matching between the PSD and the crack width, the surface response optimization method is adopted to determine the optimal PSD (OPSD) of lost circulation materials (LCMs) and plot the effective plugging data points in the ternary diagram. To simulate the multiscale fracture distribution in a wellbore, a multislit plate plugging apparatus (PPA) is used to evaluate the leakage of plugging materials with different PSDs. The PSD test results show that the OPSD has a multipeak structure, which is conducive to plugging cracks of different sizes. Compared with the ideal packing theory, this method, conducive to the later removal of the plugging material and recovery of carbonate reservoir productivity, is more applicable to fractured carbonate reservoirs and testing the involving oil, also to estimate the acid dissolution of the plugging layer, which shows that the dissolution percentage of the plugging layer is 95.9%. Hence, it is able to achieve the reservoir protection effect. The field application indicates that the new method possesses the capability to effectively prevent the leakage of small- and medium-sized fractures in carbonate reservoirs, which ensures safe and effective drilling.