Investigation of the disperse composition and strength of granules of instant drinks

В условиях высокой занятости населения возникает необходимость развития более сбалансированного питания. Одним из таких продуктов могут выступать инстантированные напитки на основе плодово-ягодного сырья. Подавляющее большинство таких продуктов на рынке представлено в виде многокомпонентного гранулятора с заданными показателями качества. При производстве таких продуктов используются грануляторы различного типа, однако для малых производств, которые могут быстро переориентироваться на выпуск новой продукции, более перспективными являются грануляторы периодического действия, например, роторные смесители-грануляторы. Однако при анализе получаемого дисперсного состава было выявлено, что продукт имеет нестабильный гранулометрический состав. В работе исследовались дисперсный состав и прочность гранулированного продукта, полученного в роторном смесителе-грануляторе. В результате литературно-патентного обзора была предложена модернизация известного гранулятора и определен дисперсный состав получаемых гранул. В результате проведенных исследований было выявлено, что гранулометрический состав готовой продукции стал более стабилен по сравнению с прототипом оборудования. При анализе прочности получаемых гранул не было выявлено существенного изменения, однако была выявлена зависимость прочности на раздавливание от частоты вращения рабочих органов, так при увеличении частоты вращения лопасти выше 2000 мин-1 наблюдался рост прочности гранул. Также при увеличении частоты вращения происходит рост мелкодисперсной фракции в готовой продукции. Обработка полученных результатов исследований позволила получить экспериментально статистическую модель зависимости среднемедианного размера получаемых гранул от режимных параметров и свойств связующего раствора. In conditions of high employment of the population, it becomes necessary to develop more balanced nutrition. One of the types of such foods can be instantized drinks based on fruit and berry raw materials. An overwhelming majority of these foods on the market are presented in the form of a multicomponent granules with specified quality indicators. When manufacturing such foods granulators of different types are used, however, for minor productions that can be quickly reorientated to the release of new foodstuffs, periodical activity granulators are more promising, for example, rotary mixers-granulators. However, when analyzing the resulting dispersed composition, it was revealed that the foodstuff has an unstable particle size distribution. The work investigated the dispersed composition and strength of the granular staff obtained in a rotary mixer-granulator. As a result of the literature and patent review, the modernization of the well-known granulator was proposed and the dispersed composition of the resulting granules was determined. As a result of the research carried out, it was revealed that the granulometric composition of the finished staff became stabler in comparison with the prototype of the equipment. When analyzing the strength of the granules obtained, no significant change was revealed, however, the dependence of the crushing strength of the working bodies’ rotational speed was revealed, so, with an increase in the blade’s rotational speed over 2000 RPM, an increase in the strength of the granules was observed. Also, with an increase in the rotational speed, an increase in the fine fraction in the product finished occurs. The processing of the research results obtained made it possible to obtain an experimental statistical model of the dependence of the average median size of the granules obtained on the operating parameters and the properties of the binder solution.

Improving Separation Efficiency in End-of-Life Lithium-Ion Batteries Flotation Using Attrition Pre-Treatment

The comminution of spent lithium-ion batteries (LIBs) produces a powder containing the active cell components, commonly referred to as “black mass.” Recently, froth flotation has been proposed to treat the fine fraction of black mass (<100 µm) as a method to separate anodic graphite particles from cathodic lithium metal oxides (LMOs). So far, pyrolysis has been considered as an effective treatment to remove organic binders in the black mass in preparation for flotation separation. In this work, the flotation performance of a pyrolyzed black mass obtained from an industrial recycling plant was improved by adding a pre-treatment step consisting of mechanical attrition with and without kerosene addition. The LMO recovery in the underflow product increased from 70% to 85% and the graphite recovery remained similar, around 86% recovery in the overflow product. To understand the flotation behavior, the spent black mass from pyrolyzed LIBs was compared to a model black mass, comprising fully liberated LMOs and graphite particles. In addition, ultrafine hydrophilic particles were added to the flotation feed as an entrainment tracer, showing that the LMO recovery in overflow products is a combination of entrainment and true flotation mechanisms. This study highlights that adding kerosene during attrition enhances the emulsification of kerosene, simultaneously increasing its (partial) spread on the LMOs, graphite, and residual binder, with a subsequent reduction in selectivity.

Carbonized Steel-Smelting Slag Is a Promising Raw Material for the Production of Artificial Concrete

Obtaining an artificial stone based on steel-smelting slag is possible as a result of carbonization of the feedstock in carbon dioxide. The feedstock - slag and carbon dioxide - are by-products from steel smelting in electric furnaces, which must be disposed of in order to improve the environmental situation in the region. The condition for obtaining the cementing ability of steelmaking slag is the preparation of a charge with certain properties and maturation technology: humidity, dispersion of the fine fraction and the maximum size of the coarse fraction, the ratio between the coarse and dispersed fractions, the concentration of carbon dioxide in the gas-air environment, temperature, pressure and flow time. carbonization reactions in the reactor, the magnitude of the pressure during the production of pressed articles, the process of stone maturation in the post-carbonization period.

Grain size distribution of waste rock masses of Kuzbass coal strip mines

Grain size distribution as a structural characteristic of waste rock and bulk masses in the course of mining and construction works acquires quantitative values in the process of rock blasting and hauling of rock mass. Such physical-mechanical and structural-textural parameters of a rock mass, as the ultimate strength of rocks and rock mass, fracturing, diameter of the natural rock jointing, have a significant impact on the blasted rock mass grain size distribution. On the other hand, such characteristics as stability, permeability of waste rock masses largely depend on the lithology and grain size distribution of the loosened rocks composing waste rock dumps and their height distribution within a dump. The paper describes the findings of the study of the grain size distribution of waste rock masses of Kuzbass coal strip mines and the features of its spatial variations within the masses. The textures of the bulk masses and physical and technical properties of the stacked rocks were studied both at the Kuzbass waste rock sites and in laboratory conditions. The grain size distribution of the fine lump part of the dumps with the lump size up to 50 mm was investigated by sieve method according to GOST 12536–2014, and the medium and large lump part was studied using oblique photoplanimetry. The field observations showed that the bottom part of the rock dumps, dumped by peripheral bulldozer or excavator methods was composed of coarse fraction with average lump size of: d_cr = 0.8–1 m, while the middle part, of rock lumps of d_cr = 0.4–0.6 m, and the upper part, mainly of fine fraction with lump size of less than 0.1 m. The ratio of length, width, and thickness of the blasted rock lumps was 1:0.85:0.8, which corresponds to elongated-flattened shape of the lumps. This requires significant number of coordinates for describing the lump positions in the rock mass, as well as taking into account the moments of inertia when modeling the motion of such lumps until they reach a stable position. Up-to-date non-commercial or commercial software and corresponding hardware can be used to take into account non-isometric shape of the lumps when modeling their motion.

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

Bacterial aerosol, particulate matter, and microclimatic parameters in the horse stables in Poland

Keeping horses in good condition requires providing them with living conditions that meet welfare requirements. These animals should be accommodated with suitable space, access to high nutritional fodder and water, and a suitable microclimate in their shelters. When it comes to the environment in the stables, a serious problem is created by particulate matter (PM), which consists of bacteria. PM concentration may be responsible for developing multiple lower respiratory tract diseases in horses, including allergies and recurrent airway obstruction (RAO). In turn, these ailments may lead to decreasing equine physical and mental fitness. Additionally, people who spend time in the stables are exposed to the same harmful factors. The study was conducted in Udórz Stud Farm located in the southern region of Poland. The study was carried out in 2 different types of stables: 3 runners (a type of stable where horses are housed together and occasionally linked up, e.g., for feeding or grooming) and 2 box stables. The research continued for 2 years and the samples were collected in each season. The bioaerosol samples were collected using a six-stage Andersen-Graseby cascade impactor to assess size distribution and concentrations of airborne bacteria. PM concentration was analyzed using the DustTrak™ II Aerosol Monitor 8530, while microclimate parameters were measured using the Kestrel 5000 Weather Meter. There are almost no studies concerning size distribution of airborne bacteria, individual PM fractions, and the impact of everyday handling on the changes in the bioaerosol and PM concentration. This preliminary study provided basic information on this subject. We have revealed a strong correlation between high PM and bacterial aerosol concentrations. Higher contamination levels were recorded in runners, as compared to box stables. The highest bacterial aerosol level was detected in the spring. The analysis of the fractions of the bacterial aerosol in the stables indicated the highest share of ultra-fine fraction (0.65–2.1 µm), while respirable fraction (below 4.7 µm) exceeded 75%. It was established that the concentration of the bacterial aerosol inside the stables was many times higher than outside. It depended significantly on everyday activities undertaken in the stables, like feeding or cleaning. Taking the above into account, a different cleaning system should be developed (a wet cleaning system, with the use of water) and excrement should be removed more frequently.

Sedimentological and Grain Size Characteristics of Two Lake Cores from Himachal Pradesh, India

Two lake cores from Khajjiar (length 746 cm) and Rewalsar lakes (length 647 cm) in Himachal Pradesh (India) were retrieved to understand the sedimentological characteristics and variation in grain size distribution. Both the lake cores are Upper Holocene in age. The Rewalsar lake sediments are composed predominantly of silt with small amounts of clay, whereas the Khajjiar sediments contain sand, silt and clay and both cores have high carbonaceous matter. The standard deviation ranges from 0.88 ϕ to 2.56 ϕ for Khajjiar lake and from 0.957 ϕ to 2.264 ϕ for Rewalsar lake, indicating poorly to very poorly sorted core sediments. The values of the Kurtosis vary between 0.678 ϕ and 1.205 ϕ for Khajjiar lake and from 0.8 ϕ to 1.2.4 ϕ for Rewalsar lake, viewing platykurtic to leptokurtic nature. Further, the skewness value ranges from -0.097 ϕ to 0.240 ϕ for Khajjiar lake and 0.079 ϕ to 0.25 ϕ for Rewalsar lake revealing fine to symmetrical skewness model. The bivariate plots by using the grain-size parameters were also interpreted. The Total Organic Carbon (TOC) is higher in the Khajjiar lake sediments (0.9 to 31.2%; av. 10.6%), compared to that in the Rewalsar lake sediments (1.0 to 9.0; av. 2.6%). The sedimentological characteristics indicate that the energy conditions were linked to the climatic conditions prevailing in the area. In general, the Khajjiar lake core is composed of relatively coarser sediments and more affected by arid conditions while the fine fraction of the Rewalsar shows the consequence of lower energy conditions. The Khajjiar lake shows the transition from fluctuating conditions (zone 1) to humid (zone 2) to arid (zone 3), while the Rewalsar shows the change from fluctuating (zone 1) to humid conditions (zones 2 and 3). The similarity between zone 1 and 2 of both the lake profiles shows that both lakes have experienced similar climatic conditions during the deposition, revealing domination of fluctuating and arid conditions.

Multimodal spectroscopy with chemometrics for the forensic analysis of the inorganic content of Western Australian sandy soils

This study demonstrates a multi-modal analytical sequence suited to the characterisation of sandy soils, which remain an underutilised form of forensic trace evidence. Within the Swan Coastal Plain in Perth, Western Australia, most soils are heavily leached with only small deviations in their mineral compositions. Traditional soil analyses are hence rendered inappropriate for use due to the lack of clay and organic matter. This has led to inorganic methods of analysis predominating, in addition to experimentation with modified techniques. One example is utilisation of the quartz-recovered fine fraction, which is suitable for dry, quartz-dominated sandy soils. In this study, preliminary investigations used the spectroscopic techniques microspectrophotometry, infrared spectroscopy, and x-ray diffraction, to develop a multi-faceted approach for the forensic analysis of the quartz fine fraction of soils. These data were then combined with principal component analysis to demonstrate how chemometrics can assist with objective characterisation and differentiation of sandy soil samples for forensic purposes. Chemometric analysis has not previously been attempted with data obtained from the quartz fine fraction. This methodology is transferable to other jurisdictions where dry, sandy soils predominate.