Fine Grinding Research Articles

Technical aspects of peanut butter production processes: Roasting and grinding processes review

A concise understanding of technical aspects underpinning successful peanut butter production is critical for the peanut butter industry. This paper reviews the critical technical drivers of quality peanut butter production. The synergetic relationship between roasting, grinding and stabilization processes and corresponding physiochemical changes and their influence on peanut butter color, flavor, texture, storage stability, shelf life, and overall consumer product acceptance is discussed. Potential of promising novel technologies like infrared, microwave roasting, and some novel peanut butter stabilization methods is evaluated. Quality of peanut butter is by far determined by temperature–time profile used in roasting, fineness of grind, type(s) and amount of added ingredients. The synergistic relationships between production technical aspects and resultant quality of peanut butter are more complex than what is usually assumed. Further research on the novel technologies like infrared and microwave roasting is still required for them to be fully adopted in the peanut butter industry. Practical applications Far from the general erroneous assumptions that peanut butter production is a simple process that does not require much technical and scientific rigor, successful and high-quality peanut butter production is informed by a solid technical and scientific knowledge base. The problems of poor peanut butter quality can be easily addressed by tapping from this scientific base. This study provides a single point, comprehensive reference source material on the technical drivers of peanut butter quality attributes from a processing perspective. Researchers, process, and production engineers can use this base knowledge in designing and optimization of peanut butter production processes. A clear understanding of the link between processes and physiochemical changes that are influential on peanut butter quality can be a key technical enabler to the peanut butter industry.

Analysis of grinding aid performance effects on dry fine milling of calcite

The control mechanism in the production of fine particles is important in dry grinding processes, which are popular in the grinding of some minerals. The behavior of the fine particles with each other and with the mill environment is complex and needs to be investigated in detail (on a micro-scale) in every application. One of the parameters controlling the fine particles in a mill is the use of the correct amount and type of grinding aid. Mechanisms of action must be understood well to develop grinding aids and fully utilize their positive effects. As a general explanation, with the use of grinding aids, the production tonnage can be increased at the desired product fineness, as well as achieving a finer product at the same production tonnage. However, it is necessary to know other mechanisms and effects to increase efficiency and correct use. The influence of grinding aids on the dry fine grinding of calcite using several analysis methods was revealed in the present study. Within the context, the results were assessed considering grinding performance (particle size distribution and size reduction ratio), product quality (color properties), flowability, adsorption properties (FTIR), and agglomeration behavior (SEM). Moreover, the tested effect of each grinding aid was discussed for each analysis, and the collected results were combined around a summary core diagram.

Surface form error measurement for rough surfaces using an infrared lateral shearing interferometry

The fabrication of a large monolithic mirror or a segmented mirror requires a high throughput that satisfies the time-cost requirement. Particularly, the rough surface properties of grinding pose a challenge for accurate measurement of the surface figure error (SFE). If the SFE during grinding is as small as possible, the material removal volume in the figuring process gets reduced, and the total required time of the fabrication is greatly minimized. In this paper, we propose a new metrology tool called intermediate surface figure error measurement (ISFEM) that can be applied to measurement of SFE for rough surfaces. It consists of a CO2 laser of wavelength 10.6 µm as a light source, a lateral shearing interferometer as a wavefront sensor, and several optical components for beam shaping and imaging. The ISFEM demonstrated its ability to measure the microns to sub-micron rms SFE of the ground surface by testing the samples with a 0.59 µm -1.56 µm rms of surface roughness and a large SFE of about 3 µm rms. The system was applied to the fabrication of an off-axis parabolic mirror of diameter 1.1 m, where it successfully performed as an intermediate metrology between laser tracker measurement for the rough surface and interferometric measurement for the polished surface. The ISFEM obtained measurements from 3.88 µm rms SFE during the fine grinding process and down to 0.38 µm rms during the polishing process. Therefore, we confirmed that the ISFEM provides a unique solution for high throughput for the fabrication of large or multiple segmented mirrors.

Retrieval of DTM under Complex Forest Stand Based on Spaceborne LiDAR Fusion Photon Correction

The new generation of satellite-borne laser radar Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) data has been successfully used for ground information acquisition. However, when dealing with complex terrain and dense vegetation cover, the accuracy of the extracted understory Digital Terrain Model (DTM) is limited. Therefore, this paper proposes a photon correction data processing method based on ICESat-2 to improve the DTM inversion accuracy in complex terrain and high forest coverage areas. The correction value is first extracted based on the ALOS PALSAR DEM reference data to correct the cross-track photon data of ICESat-2. The slope filter threshold is then selected from the reference data, and the extracted possible ground photons are slope filtered to obtain accurate ground photons. Finally, the impacts of cross-track photon and slope filtering on fine ground extraction from the ICESat-2 data are discussed. The results show that the proposed photon correction and slope filtering algorithms help to improve the extraction accuracy of forest DTM in complex terrain areas. Compared with the forest DTM extracted without the photon correction and slope filtering methods, the MAE (Mean Absolute Error) and RMSE (Root Mean Square Error) are reduced by 51.90~57.82% and 49.37~53.55%, respectively. To the best of our knowledge, this is the first study demonstrating that photon correction can improve the terrain inversion ability of ICESat-2, while providing a novel method for ground extraction based on ICESat-2 data. It provides a theoretical basis for the accurate inversion of canopy parameters for ICESat-2.

Effect of operating conditions on the particle size distribution and specific energy input of fine grinding in a stirred mill: Modeling cumulative undersize distribution

Simulation of the fine or ultra-fine grinding process by Population Balance Model (PBM) has its restrictions because some coarse particles maybe disappear or the breakage rate exhibits complex non-first-order breakage kinetics during the grinding process. In this study, the influence of grinding media diameter, stirrer tip speed, media fulling rate, and powder filling rate on the uniformity of particle size distribution and specific energy input were studied in a stirred mill. The cumulative undersize distribution of ground products was simulated by the Rosin-Rammler-Benne (RRB) function, from which the parameter k and characteristic particle xe of the RRB function were obtained. The time-dependence of the parameter k was investigated. And, the Walker model for describing the reduction in characteristic particle xe with specific energy input was examined. Based on these results, combining the Walker model with the RRB function to simulate the cumulative undersize distribution of ground products. Thereby, a new cumulative undersize distribution of the prediction model was developed, which was successfully validated by the experimental data against predicted data.

Distribuição de recursos agrominerais no tempo e no espaço – uma perspectiva geológica global

Abstract Agromineral resources are minerals and rocks used to improve soil productivity and health. These resources can be applied: indirectly, by extracting and concentrating one or more minerals by industrial processes for the production of conventional, highly soluble fertilizers; and directly, without processing, except fine grinding, for direct soil application. Agromineral resources include sedimentary phosphates, limestones/dolostones, potash and glauconite-bearing rocks of sedimentary origin, basaltic rocks, phonolites, kamafugites, and glass-rich mafic rocks of igneous origin. Among metamorphic agromineral resources, marble and biotite schist stand out. However, agromineral resources are not equally distributed on Earth’s surface, occurring more in one area than in another, and have accumulated in various geotectonic settings related to plate tectonics, being formed in specific geological time periods in Earth’s history. Therefore, these resources occur in specific “agromineral provinces” and were formed during specific “agromineral epochs”. This paper provides a conceptual framework for agromineral resource distribution in time and space. Agrominerals have a high potential to be used as directly applied soil amendments and soil remineralizers for new and innovative farming strategies, provided the amendments are low or free of contaminants.

Optimization of the continuity of the aspherical production processes in asphericon s.r.o based on subsurface damage and microroughness analysis

In the paper is presented an analysis and optimization of the standardized sub-apertural grinding process used in the serial production in asphericon s.r.o. The monitored parameter was the depth of subsurface damage and surface microroughness. Tested were five grinding processes, which were automatically generated by the internal system, for five different diamond grit sizes (D151, D91, D64, D30, and D15). For evaluation of the depth of the defected layer was used modified wedge polishing method which is suitable for analysis of the rotationally symmetrical sub-apertural grinding processes [1]. For identifying the presence of the subsurface damage two methods were used. Defect detection using an optical microscope, as the broadly used and reliable method, and detection by standard ISO control to get the comparison with the method used in common serial production. The microroughness was measured using a white-light microscope concerning the used grinding tool and the amount of removed material. Within the experiment was found as the most effective two-step process uses D91 for rough grinding and D30 for fine grinding. D91 provides a very good removal characteristic with final subsurface damage of 44 µm which is possible to grind out using the D30 tool in two steps with final subsurface damage 22 µm in a total processing time of 137 minutes. This grinding process is timewise in best balance with 80 minutes long polishing process and therefore minimize the production cost. Result microroughness around 2 nm Sq in the fully polished zone is already limited by the polishing process. Using a finer grinding tool is not bringing improvement in the surface microroughness just shortening polishing time due to lower subsurface damage.

Influence of nano α-Al2O3 as sintering aid on the microstructure of spray dried and sintered α-Al2O3 ceramics

Alpha Alumina (α-Al2O3) has traditionally been sintered to near theoretical density by employing variations in raw material properties, particle sizes, grinding methods, compaction pressures, sintering aids or minor quantities of additives and sintering temperatures. All these parameters directly influence the grain growth morphology and microstructure of the sintered alumina ceramic characteristics. Growth of large grained microstructure facilitated by fine grinding of raw material and coalescence of the grains enhanced by dopant additions are well researched. The maximum sintered density and strength of the fired body could be attained through large grained microstructure which include near spheroidal grains. Most of the final sintering is accomplished via additions of suitable aids which also may be promoted by liquid-phase sintering which is considered highly advantageous compared to solid-state sintering for products in many defense applications. In this paper the influence of nano α-Al2O3 (<100 nm particle size) as sintering aid to obtain the desired microstructure in sintered micron sized (1 to 5 µm) α-Al2O3 is being reported. 1.0 and 1.5 wt% nano α- Al2O3 powder were spray dried with 99.0 and 98.5% α-Al2O3 powder respectively, with polyvinyl alcohol binder, compacted into 10 mm dia and 5 mm thick pellets and sintered at 1450 °C with 3 h soak time. In addition to the two different sintering aid additive percentages, other variables included are spray dried powders removed from (i) chamber and (ii) cyclone. The sintered ceramics were characterized for bulk density and fracture surface microstructure via SEM analysis. Nano alumina as sintering aid exhibited significant influence that included generation of microstructure with porosity, precipitation or liquid phase sintering. The study was limited to establishing the definitive role played by nano alumina to influence the sintering of micron alumina.

Analysis of scientific trends in the research of the movement of grinding bodies at fine grinding of rocks

Analysis of scientific trends in the research of the movement of grinding bodies at fine grinding of rocks

Physical Processes in the Thermal Vacuum System

Physical processes occurring during dehydration of heterogeneous materials in a thermal vacuum system have been analyzed. It has been demonstrated that the thermal-vacuum method provides dehydration and simultaneous wet-stock dispersion due to thermal diffusion, shock-wave and ionization effects, thereby leading to formation of novel-type nanodispersed material at minimum energy input. In recent years the intensification of production processes, as well as the solution of energy- and resource-saving problems have taken on great significance. For the sake of dehydration working-cycle improvement, combination of several process procedures in a single installation is used, resulting in both the intensification of the production process and the reduction in capital expenditures. There are the facilities, where the simultaneous use of mechanical grinding operation and the drying process is practiced. In this case, a preheated air is used as a drying agent, and this considerably increases the energy demands of the technological process. This phenomenon is attributed to the impact action and friction of material particles against grinding surfaces of the mill, to the appearance of new surfaces at crushing, and also, to the dust-gas mixture turbulence in the mill working area. That requires substantial power consumption and prevents from obtaining the product with desirable indicators, in particular, the with dispersion and moisture content, which substantially affect the quality of materials produced from fine-grained products. The analysis of fine grinding methods has shown that the most rational method of material grinding is the combination of impact loads. The impact loads facilitate the structure destruction of wet stock, while the abrasion loads acting in the field of high turbulent flows lead to the material destruction. The aim of the present work has been to define the physical processes in the thermal vacuum system, which can efficiently provide dehydration along with simultaneous dispersion of wet material, yielding a dried and ground feedstock in a short span of time.

Analysis of intensification methods for fine dry-ground powder materials

The paper describes the influence of various intensifiers on the material grinding process. The most well-known method for intensifying chip grinding consists in the use of polymethyl methacrylate (PMMA), a high molecular weight polymer additive. It intensifies crushing of steel chips as compared to grinding in the air or in alcohol and reduces the oxygen content in the metal phase, improving the properties of the resulting powder. However, contamination of the powders with polymer degradation products significantly limits the applications of this method for intensifying chip grinding. Based on the data in various studies, gases may be rated as follows in terms of their effect on the disintegration of metal powders: hydrogen &gt; helium &gt; argon &gt; nitrogen &gt; air. When comparing the intensification of fine grinding of metal powders with the use of PMMA and a gaseous medium, it may be concluded that both methods have a common major drawback, which is the contamination of the finished powders with the products of interaction between the grinding intensifiers and the material being ground. In order to improve the disintegration efficiency of metal powders and minimize the negative effect, a wide range of experimental studies will be required, with the grinding of metal waste not only in gaseous, but also in liquid media, as well as with the use of surfactants. A comprehensive study of the effects of various media and surfactants on the grinding kinetics, both when used individually and in combinations, may help identify the best intensifiers that would eliminate the unnecessary contamination of the grinding products.The study was carried out under the grant issued by the Russian Science Foundation (project No. 20-79-10125).

Shungite-bearing rocks of the Zazhoginskoe ore field (Republic of Karelia): geology to processing technology

The article demonstrates the unique nature of shungite-bearing rocks, reflected in their geological, genetic, structural, physical, molecular, supramolecular, and electronic-energy characteristics. The study was based on the nine levels of high-carbon shungite rocks in the volcanogenic-sedimentary complexes of the Onega structure of the Paleoproterozoic Zaonezhskaya suite with an age interval of 2100 to 1920 Ga. The high-carbon shungite rocks of the Zazhoginskoe ore field are dominated by shungite matter and silica. No examples of shungite-bearing rock processing can be found anywhere in the world. There are several practical applications of shungite-bearing rocks, based on different grinding fineness classes (micro- and nanoscale). The paper describes various methodological approaches to shungite-bearing rock processing for the activation of shungite carbon. Experimental data have been obtained for methods that ensure a significant removal of aluminosilicate and silicate components, but have not been introduced in the industry. The paper presents the results of new studies for high-carbon shungite rocks using a combination of mineralogical and industrial methods for selecting the sample crushing/grinding size and ensuring the liberation of minerals using a concentrator table, as shown in the shungite-bearing rock separation diagram. The research is aimed at developing the theory and methods for sustainable subsoil use. Shungite-bearing rocks are being increasingly regarded as a multi-purpose raw material for various industries and spheres of life.The work was carried out with the financial support of the topic research 210 of IG KarSC RAS 121040600173-1.

PROCESSING OF HARDENED CYLINDRICAL GEAR WHEELS OF THE CUTTING GEARBOX OF THE COMBINE UKD 200-500

The article discusses the latest developments of unique technological methods of gear milling of cylindrical gears for preliminary blade gear processing of hardened cylindrical gears of the cutting reducer of the UKD200-500 coal mining harvester for the final gear grinding of gear teeth with modulus m = 16 mm, with hardness HRC 56 ... 62. The peculiarity of the design of special hob cutters is that a circle passing through the lower boundary points of the involute is used as the palloid of the machine gearing of the tool and part. Pre-cutting the teeth of hardened wheels with carbide milling cutters allows you to remove the main allowance for the final gear grinding.

The effect of the filling degree of the tumbling mill chamber on the bifurcation value of the froude number

The influence of the filling degree of the drum chamber on the bifurcation value of the Froude number in the case of self-excitation of self-oscillations of a two-fraction granular charge with a minimum swing is considered. Such a pulsating mode of the charge movement is used in the self-oscillating grinding process in a tumbling mill. The coarse fraction that simulated the milling bodies consisted of spherical particles of an incoherent granular material with a relative size in the chamber ψb=0.00733. The fine fraction, simulating the material to be ground, was cement with a relative particle size ψm≈0.092∙10-3. The value of the adopted analogue of the kinematic viscosity of the two-fraction granular loading approached the value of 10-3 m2/s. The main variable factor in experimental studies was the filling degree of the drum chamber with loading at rest κb=0.25, 0.35, and 0.45. An additional factor was the degree of filling the gaps between the spherical particles of the coarse fraction with particles of the fine fraction κb=0, 0.25, 0.5, and 1. The method of visual analysis through the transparent end wall of the chamber of transient processes of the loading behavior with a smooth change and fixation of the velocity was applied. The bifurcation minimum value of the rotation speed was recorded, at which the steady-state circulation mode of the load movement turns into a transient pulsation one with a minimum swing. A decrease in the bifurcation values of the Froude number Frb on the cylindrical surface of the chamber with an increase in κb has been established. An increase in the intensity of the decrease in Frb with an increase in κm was revealed. The recorded effect is due to an increase in the connected properties of a two-fraction loading during self-excitation of self-excited oscillations with an increase in κb and κm. The numerical values of the boundaries of the range of bifurcation values of the Froude number for a tumbling mill Frb=0.0484–1.17 have been determined. The obtained Frb range corresponds to the Reynolds value in the range Re=40–197. The maximum Frb value is obtained with coarse grinding. An increase in the likelihood of self-excitation of self-oscillations of the intra-chamber loading with a decrease in the fineness of grinding was revealed

Comparison of Volatile Organic Compound Concentrations in Ambient Air among Different Source Areas around Khon Kaen, Thailand

Volatile organic compounds (VOCs) are a complex group of chemicals that pose a direct risk to human health. They also lead to the formation of other air pollution constituents, including fine particulate matter (PM2.5) and ground level ozone (O₃). The ambient air concentrations of 19 VOCs were measured using multi-day 24 h sampling at two urban sites and two rural sites in the area of Khon Kaen, Thailand. Results showed that most VOCs were at concentrations considered acceptable according to the 24 h average standards established by the Thai Pollution Control Department. The VOC acrolein, however, was detected at concentrations (0.69–1.15 μg/m3) in excess of the 24 h average standard (0.55 μg/m3). Two other VOCs, benzene and 1,3-butadiene, were also detected at elevated levels (1.73–2.75 and 0.18–0.40 μg/m3, respectively) that indicated the potential to exceed the 1-year average standard. VOC concentrations were highest in the urban market monitoring site, suggesting that vehicle exhaust and food preparation using cooking oil at high temperatures may have been potential sources of the elevated VOCs.

Strength, permeability and microstructure of self-compacting concrete with the dual use of ferronickel slag as fine aggregate and supplementary binder

The study herein addresses the scope to maximize the combined use of by-product ferronickel slag (FNS) as a fine aggregate and ground FNS (GFNS) as a supplementary binder to enhance the sustainability of self-compacting concrete (SCC). The development of strength, permeability and microstructures of SCC containing up to 50% supplementary binder and 50% FNS fine aggregate were investigated. It was found that the fresh properties of concrete incorporating FNS and GFNS remained well within the recommended limits of the European standard for SCC. The 28 days compressive strength of high strength SCC using FNS and GFNS varied within 10% of that using natural sand and fly ash as an SCM. Splitting tensile strength and elastic modulus could be predicted by the standard equations used for conventional vibrated concrete. Tests such as volume of permeable voids, water absorption, sorptivity and water penetration showed good physical properties of SCC incorporating FNS and GFNS. Investigation by SEM and EDS showed a compact microstructure by the reaction product of GFNS which is similar to that produced by pozzolanic reaction of fly ash. Overall, up to 30% cement replacement by GFNS and 50% sand replacement by FNS was found feasible for the production of SCC of high strength and good physical properties indicating high durability.

Environmental protection of a coal-mining region

Research objective is to substantiate the relevance of mining transition to eco-friendly technologies of subsurface use. Methods of research include analyzing theory and practice of environmental technologies application and carrying out a multifactor experiment. Results. An efficiency criterion for mineral resources extraction technologies is proposed that involves reducing the effect made by the by-products of mining and processing enterprises on the state of the environment. The problem is considered of minimizing the environmental damage from storing silt coal in dumps and storages by utilizing their components. The mechanism of environmental pollution has been formulated. Aspects of metal recovery from beneficiation tailings in a disintegrator mill are investigated. A reduced threat to living matter is predicted by implementing the concept of radical waste-free processing of substandard mineral raw materials. The need to improve the processes of crushing, fine grinding, and classification of minerals in mills to reduce the waste of coal production, harmful to the environment, is noted. Conclusions and scope of the results. Deteriorated conditions of mineral deposits development raise the risk of man-made impact on the environment in coal-mining regions. The global human population grows resulting in increased resources production to respond to resource needs. The growing threat to living matter can be reduced by radical measures, the non-waste processing of substandard mineral raw materials being the priority. The research results can be helpful in the development of deposits of solid metal-containing technologically exposed ores

Rheological behavior of the composite matrix Diglycidylether of bisphenol-A (DGEBA/wt% blast furnace slag (BFS)

This paper reports experiments on the rheological behavior of DGEBA epoxy resin filled with blast furnace slag nanoparticles. The study of the variation of stress and viscosity as a function of shear rate is emphasized.The purpose of this study is to investigate the rheological behavior of DGEBA loaded with blast furnace slag (BFS), the selected mixtures cannot exceed 10% in wt%, given the fineness of grinding which SSB= 44.5 m2.g-1. We tested the compositions of DGEBA/%wt blast furnace slag (BFS) at filling ratios of (10, 20, 30, 40 and 50%). Viscosity and shear stress as a function of temperature and filler rate were investigated. In this study, formulations were developed to test the best compositions with favorable rheological behavior for better processing of these matrices.

Monitoring of the Effect of Grinding Raw Material Mixture and Soaking on the Formation of Monoclinic Phases of Alite

The article monitors the effect of length of grinding in the process of homogenization of raw material mixture and soaking on the number of monoclinic phases of alite M1 and M3 in the sample using the Rietveld method. The wet grinding process in the water environment in the planetary mill PULVERISETTE 6 was chosen for the preparation of raw material mixture. Based on previous research in this area, two firing temperatures 1450 and 1550 °C with soaking of 30, 60 and 90 minutes were selected. The results showed the monoclinic phase M1 is more readily formed during coarser grinding, during which large crystals of M1 are formed. On the contrary, the monoclinic phase M3 is formed at a higher firing temperature, at a larger amount nuclei and finer grinding. The results show that the grinding time has an important effect on the rate of formation of monoclinic phases.

PSV-11 The effects of pelleting and extrusion on nutrient composition and protein quality measurements in a variety Canadian pulses

Abstract Alternative forms of protein are an important focus in nutrition. This study sought to compare the effects of pelleting and extrusion on nutrient composition and protein quality measurements of Canadian pulses. Pulses used for the study included: 2 pea variety (Amarillo and dunn), lentils, chickpeas, and faba bean. Ingredients were ground through a 10/64” or a 2/64” screen to create a coarse and fine ground product, respectively. Both coarse and fine ground ingredients were pelleted at 60–65, 70–75, and 80–85 C0. Fine ground ingredients were extruded at three different temperatures (110, 130, 150 C0) and two moisture levels (18 and 22%). Samples were collected for all runs at the beginning, middle, and end of each run for both pelleted and extruded samples. Samples were analyzed for proximate analysis, amino acids including lysinoalanine, total and damaged starch, and total dietary fibre (including insoluble and soluble). Data were analyzed using a mixed model via proc glimmix in SAS, where ingredient, process, grind, temperature, and extrusion moisture were treated as fixed effects with different interactions selected based on model investigated. Crude protein content of whole pulses was highest in faba bean and lowest in the Amarillo pea, with faba bean protein content significantly higher than all other pulses, and lentil protein content significantly higher than Amarillo peas (P &amp;lt; 0.05). All pelleting temperatures, nested within grind, significantly increased crude protein content of all pulses compared to whole pulses (P &amp;lt; 0.05). All extrusion moistures significantly increased crude protein content of all pulses compared to whole pulses (P &amp;lt; 0.05) and moisture/temperature interactions were significantly higher for all pulses compared to whole pulses (P &amp;lt; 0.05). Amino acid comparisons produced similar significant results. This suggests that pelleting and extrusion processing can have a positive impact on protein content of pulses and protein quality measurements in pulses.