Particle Size Of Raw Materials Research Articles

SIFAT FISIK DAN MEKANIK PAPAN SEMEN DARI LIMBAH PENGGERGAJIAN BERDASARKAN UKURAN PARTIKEL DAN KOMPOSISI SEMEN

This study aims to examine the physical and mechanical properties of cement boards from sawing waste based on raw material composition and particle size, as well to get the best sawing waste particle size and raw material composition according to JIS A5417-1992 standard. The research was carried out at the Wood Workshop Laboratory, Wood Technology Laboratory, Wood Processing Laboratory and PT Duta Pertiwi Nusantara Pontianak. This study uses a completely randomized factorial design (CRD) with two factors, namely factor A (Particle Size) and factor B (composition of cement). The results showed the average value of density ranged from 0.6878 to 0.8094 gr / cm3, moisture content value ranged from 6.7057 to 10.0246%, thickess swelling value ranged from 0.3996 to 0.8773%, water absorption value ranged from 27.8949 - 49.0375%, MOE ranged from 412.6563-1411.7847 kg / cm2 and MOR value ranged from 2.1529-4.5909 kg / cm2. The particle size that affects the physical properties is the value of water absorption, while the composition of the material that affects the physical properties is the density, water content, thickness development and water absorption capacity. The particle size and composition of the material which influence the mechanical properties, namely the value of the flexural firmness and fracture firmness. Based on the results of cement board testing with particle composition and cement (1:2) with particle size passing 10 mesh restrained 20 mesh yields the best physical properties of cement board that meet the standards of JIS A 5417: 1992, while none of the cement boards MOE and MOR meet the testing standards mechanical properties according to JIS A 5417: 1992.Keywords: Cement board, composition of cement, particle size, sawing waste

Influence of Particle Size on the Structural and Electrical Properties of Mn <sub>1.1</sub>Co <sub>1.5</sub>Fe <sub>0.4</sub>O <sub>4</sub> Ceramics

Dense Mn1.1Co1.5Fe0.4O4 ceramics are successfully synthesized by using micron- and nano-sized particles as raw materials in a solid-state reaction method. The results show that the grain sizes of the as-sintered ceramics decreased with the increasing amounts of nano-sized particles. Interestingly, the grain surface presents concave flakes when all nano-sized particles are used. In particular, the resistance of the grain boundaries and the migration of oxygen vacancies increased the resistivity and aging coefficient, respectively. This study indicates that it's a useful approach to modulate the structural and electrical properties by using the different particle sizes of raw materials.

Optimization of a “coal-like” pelletization technique based on the sustainable biomass fuel of hydrothermal carbonization of wheat straw

Abstract The optimization of a “coal-like” pelletization technique based on the sustainable biomass fuel of hydrothermal carbonization of wheat straw was investigated. Wheat straw was selected as the raw material. Single factor experiment was used to study effects of various hydrothermal carbonization and molding conditions on the fuel and pelletization characteristics of hydrochar pellets. Response surface methodology was used to explore the interactions of significant conditions and optimize the wheat straw hydrochar pelletization techniques. Experimental conditions included raw material particle size, hydrothermal carbonization temperature, hydrothermal carbonization time, moisture content, molding pressure, pressure holding time and compression speed. The results showed that effects of hydrothermal carbonization temperature on fuel characteristics of hydrochar pellets was significant (P 0.05). The optimized experimental conditions of wheat straw hydrochar pelletization were: hydrothermal carbonization temperature of 231 °C, hydrothermal carbonization time of 25 min, molding pressure of 130 MPa, moisture content of 13%. Higher heating value of the optimum-processed hydrochar pellets was 21.03 MJ/kg, its ash content was 2.11% and comprehensive combustibility index was 9.55 × 10−7%2/(°С3·min2). Using these optimized conditions, it could be produced the hydrochar pellets with similar energy yields and lower ash contents than lignite, as well as a product with better pelletization and fuel characteristics than its parent material pellet.

Upgrading of Iron Concentrate by Fluidized-Bed Magnetizing Roasting of Siderite to Magnetite in CO–H2–N2 Atmosphere

Efficient use of abundant low-grade siderite ores can potentially mitigate the shortage of iron ore in the iron and steel industry in China. In this work, the beneficiation of siderite fines containing high levels of carbonates was studied using a combined fluidized-bed magnetizing roasting process. The siderite was almost completely converted into magnetite under the optimum conditions of preheating at 550 °C for 30 s followed by magnetizing roasting at 550 °C for 60 s at 0.5 m/s gas fluidization velocity in a 13.3% CO + 6.7% H2 + 80% N2 atmosphere. Magnetic separation was optimized using a fineness of that grind of 89.2% of the material passing 0.074 mm and magnetic field intensity 0.2 T. Comparative trials confirmed that the enhanced measures proposed, including optimizing gas fluidization velocity, preheating of the materials, the use of a mixed reducing gas, and selection of the optimum particle size of raw materials, could improve beneficiation of siderite. A high-grade magnetic concentrate containing 62.6 wt% iron grade with an iron recovery of 89.2% was achieved. The results demonstrated an effective process to utilize siderite ores.

Determination of significant factors in high-shear granulation process of sucrose with aqueous solution of sodium lauryl sulphate using partial least square regression approach

Sucrose as one of the most commonly used raw materials in pediatric formulations is soluble and sticky excipient and its manipulation in high shear granulators may be very difficult. Therefore, to determine the correct amount of liquid binder is very important because it falls in a very narrow range and may vary due to small variations in the material properties or environmental conditions. The possibility of using the sugar as powder for granulation may be very challenging because of solubility and moisture adsorption properties of crystalline sugar, especially if the binder solution is water. The aim of this study was trying to solve these problems and produce sucrose granules using high share granulation and water as a binding liquid, with properties required for final product good performance. By reducing the sucrose particle size and improving the uniformity of the size distribution, the differences of the processes of nucleation and growth for small and large particles might be reduced. According to the variable importance or VIP scores from the developed partial least square (PLS) model, raw material particle size is as influential variable as the quantity and composition of the granulation liquid (Gra), granulation time (Grn) and impeller rate (Imp). Keywords: sucrose, particle size distribution, high-shear granulation, partial least square

Effects of particle size of raw materials on the characteristics of TiB2–SiC composites fabricated from B4C, TiC and Si powders

We studied the effects of particle size of raw materials (B4C, TiC and Si powders) on the characteristics of both TiB2–SiC composite powders and ceramics. Results show that the size of B4C and Si particles hardly affects the size of TiB2 and SiC particles because B4C is decomposed and consumed during the formation of TiB2, and Si is melted during the formation of SiC. The size of SiC particles is within the nano and submicron scale. However, the size of TiC particles determines the sizes of TiB2 particles and TiB2 grains in the composite ceramics because TiC particles serve as templates to form TiB2 particles. Consequently, the microstructure and mechanical properties of the TiB2–SiC composite ceramics are affected. The TiB2–SiC composites fabricated using nano-sized TiC powder possess smaller grain size, better dispersibility and more reasonable crack propagation path, thereby obtaining the optimal mechanical properties (Vickers hardness of 30.2 GPa, flexural strength of 732 MPa and fracture toughness of 7.37 MPa m1/2).

Effect of particle shape in grinding mills using a GPU based DEM code

The reduction in particle size of raw materials using grinding mills is an energy and cost intensive task. Optimization of grinding processes is not trivial as obtaining experimental information is extremely difficult due to the harsh environment. Thus, computational modeling is the most feasible option for obtaining information on the dynamics of the media. However, the computational cost of modeling each particle is high, resulting in the shape of the media being approximated by simple shapes, and in most cases, a reduction in the size of the mill. Even with these simplifications typical simulations take many weeks to months to complete making it infeasible for design prototyping and process optimization. In the last decade, the Graphical Processor Unit (GPU) has enabled large scale simulations of tens of millions of spheres in ball mills using the Blaze-DEM GPU code. Recently, this code was expanded to provide detailed contact detection for polyhedra using the volume-overlap method which is the most accurate approach amongst commercial and academic codes. In this study we first validated the code against experimental results for spherical and cube particle systems in a lab-scale ball mill. Thereafter, we performed a number of ball mill simulations with four additional polyhedral particle systems (truncated tetrahedra, Biluna, elongated hexagonal prisms and a mixed polyhedral particle systems) to study the effect of particle shape. This allows for a first investigation into the roles of particle angularity and aspect ratio on power draw, normal and shear power dissipation between particles, particles and lifters and, particles and the shell. We also show qualitative differences in charge profiles and force chain networks between the various particle systems.

Subcritical fluid extraction ofLycium ruthenicumseeds oil and its antioxidant activity

SummaryThe effective, energy‐saving and green subcritical fluid extraction (SFE) technology was applied to obtain the oil fromLycium ruthenicumseeds (LRSO). The optimal conditions of extraction parameters were found using response surface methodology with Box‐Behnken experimental design. The maximum extraction yield of 21.20% was achieved at raw material particle size of 0.60 mm, extraction pressure of 0.63 MPa, temperature of 50 °C and time of 48 min. Other traditional extraction technologies were comparatively used. The physicochemical property ofLRSOwas analysed and the chemical compositions indicated that they were rich in unsaturated fatty acid, β‐carotene, tocopherols and total phenolics. Furthermore, the antioxidant activity ofLRSOwas evaluated by scavenging activity of three kinds of radicals (DPPH·, ·OHand O2‐·) and lipid peroxidationin vitro. And its results showed the oil had the potential to be a novel antioxidant agent for using in the field of food, pharmaceuticals and cosmetics.

System modeling on Chinese herbal medicine process based on multi-block partial least squares

The system model of Chinese herbal medicine process is the basis for improving the precision of pharmaceutical process and ensuring the stable transmission of quality between different sections of the process. By taking the wet granulation-tableting process as the research object and using the Panax notoginsengs sapions (PNS) as a model drug, multi-block partial least squares method (MBPLS) was used in this article to build the system model of Chinese herbal medicine process, analyze the mass transmission rules in the process and improve the understanding on pharmaceutical process system of Chinese medicine. According to the process flow, the quality attributes of raw materials, granules and tablets collected in the process were divided into different data blocks, and the MBPLS method was used to establish system model. The R²Y and Q²Y of MBPLS model were 89.1% and 65.5%, respectively, indicating that the performance of the MBPLS model was good. By analyzing the parameters of MBPLS model, it was determined that the physical quality attributes of PNS raw materials and quality attributes of PNS granules were the key factors to affect the quality of PNS tablets. The particle size, bulk density and tapped density of PNS raw materials were the critical quality attributes which caused the quality variations of PNS granules and PNS tablets. MBPLS can quantify the contributions of each unit to the product quality by dividing the quality attributes into different units. It was helpful to analyze the interactions between the process units of Chinese herbal medicine and it could be applied to build system model of other Chinese herbal preparations processes.

Aspen Simulation of Two-Stage Pyrolysis/Gasification of Carbon Based Solid Waste

Thermo-catalytic cracking processes such as pyrolysis and gasification have great potential to convert carbon based solid waste to useful chemicals and energy. Although much attention has been devoted to gasification in recent years, there are still a number of challenges to full commercialisation of solid waste gasification. This work deals with two stage pyrolysis/gasification systems with great potential to produce tar free, high hydrogen content syngas from different types of heterogeneous solid waste. Advanced Aspen Plus simulation was employed in the modelling and optimization of a two-stage pyrolysis/gasification of lignocellulosic waste biomass (LWB) and refuse-derived fuel (RDF). Data required for process simulation, such as raw material elemental composition, heating value and particle size distribution, were determined by experimental measurements. Raw materials used in the process (RDF and LWB) were characterised by thermogravimetric (TGA) analysis, differential scanning calorimetry (DSC), elemental analysis and bomb calorimetry. The simulator process conditions were set based on experimental observations in laboratory scale pyrolysis and gasification experiments. Simulation of different scenarios and optimization of process parameters are presented. Based on the simulation results, under optimal conditions from each kg of RDF, 2.1 kg of gas with the heating value of 6.94 MJ/Nm3, and from each kg of LWB, 1.78 kg of gas with the heating value of 7.27 MJ/Nm3 can be obtained.

Optimization of the Binder System for Improving Workability and Thermo-Mechanical Properties of Plastic Refractories

Plastic refractory properties were studied by synthesizing two different binders in the laboratory. Liquid phosphate binders from different sources, a sol-gel bonding system, organic plasticizers, water retention agent and deflocculating agent were optimally mixed using different techniques for binder synthesis. The stability of the thixotropic behaviour of the binders varied with different compositions and techniques. Plastic refractory products were manufactured in the laboratory with an identical raw material composition and particle size distribution. Plastic refractory products with different binders were characterized based on the workability index of green mass, bulk density, cold crushing strength, modulus of rupture and permanent linear change of fired samples at 850 °C and 1200 °C. Phase and micro-structure analysis was in line with the thermo-mechanical properties of end products. The plastic refractory prepared with Binder B-1 was found to be optimal in terms of workability and thermo-mechanical properties.

Preparation and antimicrobial activity of the porous hydroxyapatite nanoceramics

Calcium hydroxyapatite porous nanoceramics (ncHAP) were prepared in the form of granules utilizing raw, high purity HAP nanopowder and methylcellulose (MC) in ratio of 60/40 wt% with the final moulding at high temperature (800–1000°C). The ncHAP's were studied by means of XRD, TEM, SEM techniques for structural and morphological characterizations. BET method was used in order to estimate the surface area, pore diameter and volume as well as the average particle size. It was found that particle size of raw material and nanoceramic prior heating (with MC) was 33 nm whereas ncHAP's size has significantly increased with sintering temperature from 136 nm up to 955 nm. X-ray diffraction clearly showed that all materials were crystallized and under given process parameters the HAP underwent dehydratation event as the content of β-TCP (tricalcium phosphate) has increased along with temperature up to 24%. The presence of β-TCP in porous nanoceramic material, might be advantageous since both phosphates have different solubility in biological media thus it is possible to affect the resorption speed. The antimicrobial activity of raw materials and nanoceramics against Pseudomonas aeruginosa as a representative of the Gram-negative bacteria has been determined in vitro and in vivo on Galleria mellonella larvae model. The results confirm that definitely nanobased biomaterials of calcium hydroxyapatite are very promising compound with high potential in biomedical applications.

Influence of the calcination procedure on the thermoelectric properties of calcium cobaltite Ca3Co4O9

Calcium cobaltite is one of the most promising oxide p-type thermoelectric materials. The solid-state reaction (or calcination, respectively), which is well known for large-scale powder synthesis of functional materials, can also be used for the synthesis of thermoelectric oxides. There are various calcination routines in literature for Ca3Co4O9 powder synthesis, but no systematic study has been done on the influence of calcination procedure on thermoelectric properties. Therefore, the influence of calcination conditions on the Seebeck coefficient and the electrical conductivity was studied by modifying calcination temperature, dwell time, particle size of raw materials and number of calcination cycles. This study shows that elevated temperatures, longer dwell times, or repeated calcinations during powder synthesis do not improve but deteriorate the thermoelectric properties of calcium cobaltite. Diffusion during calcination leads to idiomorphic grain growth, which lowers the driving force for sintering of the calcined powder. A lower driving force for sintering reduces the densification. The electrical conductivity increases linearly with densification. The calcination procedure barely influences the Seebeck coefficient. The calcination procedure has no influence on the phase formation of the sintered specimens.

Research of interaction between technological and material parameters during densification of sunflower hulls

During the biomass densification can be recognized various technological variables and also material parameters which significantly influences the final solid biofuels (pellets) quality. In this paper, we will present the research findings concerning relationships between technological and material variables during densification of sunflower hulls. Sunflower hulls as an unused source is a typical product of agricultural industry in Slovakia and belongs to the group of herbaceous biomass. The main goal of presented experimental research is to determine the impact of compression pressure, compression temperature and material particle size distribution on final biofuels quality. Experimental research described in this paper was realized by single-axis densification, which was represented by experimental pressing stand. The impact of mentioned investigated variables on the final briquettes density and briquettes dilatation was determined. Mutual interactions of these variables on final briquettes quality are showing the importance of mentioned variables during the densification process. Impact of raw material particle size distribution on final biofuels quality was also proven by experimental research on semi-production pelleting plant.

Roll Compaction/Dry Granulation of Dibasic Calcium Phosphate Anhydrous—Does the Morphology of the Raw Material Influence the Tabletability of Dry Granules?

The influence of raw material particle morphology on the tabletabilty of dry granules was investigated. Therefore, dibasic calcium phosphate anhydrous was used as a model material. One milled grade, 2 agglomerated grades with different porosities, and a functionalized structure, that is, an agglomerate formed by very small primary particles, were included. Particle size, density, and specific surface area of raw materials were measured. The starting materials and 2 fractions of dry granules were compressed to tablets. The tabletability of granules was compared to that of the powders and the influence of specific compaction force, granule size, and lubrication on tablet tensile strength was evaluated. All materials showed a loss in tabletability induced by a previous compaction step but to a varying extent. Only in case of the functionalized calcium phosphate morphology, this effect depended on the specific compaction force. In contrast to the other materials, the tabletability of functionalized calcium phosphate was influenced by the granule size. This effect was not related to an overlubrication as internal and external lubrication resulted in similar tensile strengths. A clear influence of the particle morphology on tablet strength was demonstrated by the study. The functionalized structure showed aspects of a more plastic deformation behavior. The functionalized dibasic calcium phosphate and the more porous agglomerate performed as potential filler/binder in the field of roll compaction/dry granulation.

Depression of synthesis temperature and structure characterization of ZrSiO4 used in ceramic pigments

The ZrSiO4 has been synthesized with MgO as mineralizer by a simple solid-state route at low temperature. The effect of particle size of raw materials on the ZrSiO4 formation has been studied. The formation of ZrSiO4 with and without MgO has been investigated by X-ray diffraction, thermogravimetry and differential scanning calorimeter analysis, respectively. The Fe2O3–ZrSiO4 pigments have been fully synthesized with MgO mineralizer at 1200 °C. The reflectance spectrum and color property of the Fe2O3–ZrSiO4 pigments have been measured and analyzed. Results reveal that nanopowders have a higher reactivity in synthesizing ZrSiO4, and that MgO can efficiently decrease the formation temperature of ZrSiO4 by reacting with SiO2 to 1100–1200 °C which is 200–300 °C lower than the characteristic temperature of ZrSiO4 formation. The prepared samples have most similar color properties to the commercially available pigment and the literature pigment. The method used in this work exhibits many advantages such as being free of volatile phases, safety and security, simplicity of process, low cost, environmental friendliness, indicating a more suitable method to synthesize Fe2O3–ZrSiO4 pigments for the potential applications in high-temperature ceramic pigments.

The effect of particle size on the heat affected zone during laser cladding of Ni–Cr–Si–B alloy on C45 carbon steel

Laser cladding is one of the most useful surface coating methods for improving the wear and corrosion resistance of material surfaces. Although the heat input associated with laser cladding is small, a heat affected zone (HAZ) is still generated within the substrate because this is a thermal process. In order to reduce the area of the HAZ, the heat input must therefore be reduced. In the present study, we examined the effects of the powdered raw material particle size on the heat input and the extent of the HAZ during powder bed laser cladding. Ni–Cr–Si–B alloy layers were produced on C45 carbon steel substrates in conjunction with alloy powders having average particle sizes of 30, 40 and 55 µm, while measuring the HAZ area by optical microscopy. The heat input required for layer formation was found to decrease as smaller particles were used, such that the HAZ area was also reduced.

Co-pelletization of sewage sludge and agricultural wastes

This paper concerns the process of production and properties of pellets based on biomass wastes. Co-pelletization was performed for sewage sludge from municipal wastewater treatment plant and other biomass material such as animal and olive wastes.The aim of the present study was to identify the key factors affecting on the sewage sludge and agricultural residues co-pelletization processes conditions. The impact of raw material type, pellet length, moisture content and particle size on the physical properties was investigated. The technic and technological aspects of co-pelletization were discussed in detail.The physical parameters of pellets, i.e.: drop strength, absorbability and water resistance were determined. Among others, also energy parameters: low and high heat value, content of ash and volatiles were presented.Results showed the range of raw materials moisture, which is necessary to obtain good quality biofuels and also ratio of sewage sludge in pelletizing materials.The analysis of the energetic properties has indicated that the pellet generated on the basis of the sewage sludge and another biomass materials can be applied in the processes of co-combustion with coal. Those biofuels are characterised with properties making them suitable for use in thermal processes and enabling their transport and storage.

Effect of particle size of sugar beet pulp on the extraction and property of pectin

Four sugar beet pulp (SBP) powders in different particle size were prepared by superfine grinding and ordinary pulverization methods, whose effects were investigated on extraction yield, composition and rheological properties of the pectin extracted by acid-heating method. By decreasing the particle size of raw extraction material (SBP) from 406.33 to 24.93 μm, the extraction yield increased from 15.81% to 20.50% and galacturonic acid content increased greatly from 38.51% to 59.97%. As particle size of SBP increased, rheological properties (intrinsic viscosity [η], viscosity-average molecular weight [Mv], apparent viscosity and activation energy) of SBP pectin were significantly increased. All pectin samples showed a strong shear thinning behavior and the same linear viscoelastic properties. The difference in particle size of SBP affected the dynamic moduli of extracted pectin. Scanning electron microscope (SEM) observations revealed the surface morphology of four SBP powders. The morphology of different roughness could make an effect on the extraction and property of pectin.

CHEMICAL AND MINERALOGICAL ASSESSMENT OF CLAYS FROM PELOPONNESE (S. GREECE) AND THEIR EVALUATION FOR UTILIZATION IN CERAMICS INDUSTRY

Mineral constituents, particle size and chemistry of ceramic raw materials may control the way ceramic products are formed and fired. Three compound (combined mixtures of 20 raw samples) clay samples from Chanakia area, Pelloponnese (S. Greece), were mineralogically and chemically investigated and their utilization as raw materials for the ceramic industry was evaluated. These samples come from different clay formations, they have red, blue and green colors and constitute the raw materials for a local brick plant. Particle size distribution analysis showed that the percentage of clay size fraction (d<2μm) ranges from 28.3 to 36.3 wt.%. X-ray diffraction analysis revealed that the main mineral constituents are quartz, micas, feldspars (plagioclases, orthoclase), calcite (except the red - clay) and clay minerals (discrete illite, mixed - layered illite/smectite, chlorite and traces of smectite and vermiculite). Projection of their bulk chemistry on some triangular discrimination diagrams has aided us to evaluate their suitability for ceramics production, namely majiolica (earthenware), cottoforte, gres and bricks were evaluated. In conclusion, all the studied materials are proved unsuitable for high quality ceramic products. Specifically, the blue and green clays were found suitable for earthenware ceramics as are high porosity building bricks, roofing tiles and similar products, while the red clay is appropriate for gres ceramics as are the low porosity tiles and bricks.