Experimental Study on the Crushing Properties of Corn Stalks in Square Bales

With the development of straw baling mechanization technology, straw is stored in the form of square baling or round baling. At present, hammer mill or the guilt-cutting and rubbing combined mill is widely used to crush square bales of straw. These two kinds of crushing equipment have disadvantages such as low productivity, large power consumption, and poor crushing effect. This paper aims to study and analyze the crushing characteristics of square baled straw after unbaling, and lay a theoretical foundation for the later research and development of a special square baled straw crusher with high productivity, low power consumption, good crushing effect, and the simulation of the square baled corn straw crushing process. For this purpose, this study carried out a corn bale crushing experiment on the Instron 8801 fatigue test machine, and studied the effects of blade angle, water content and loading speed on corn bale crushing force through the response surface method. Test results showed that the crushing process includes the compression stage and shearing stage; in terms of single factor effect, with the increase in water content and blade angle, the crushing force of the corn bale increased, but the loading speed had no significant effect on the crushing force of the corn bale. In terms of interaction effect, there was interaction effect between moisture content and blade inclination angle, when moisture content was 10%, with the increase in blade inclination angle, the incremental speed of the crushing force also increased gradually. When the blade inclination angle was 10°, with the increase in moisture content, the incremental speed of the crushing force also increased, and the interaction effect of them jointly acted on the crushing force of the corn bales.

Study of a Waste Kaolin as Raw Material for Mullite Ceramics and Mullite Refractories by Reaction Sintering

A deposit of raw kaolin, located in West Andalusia (Spain), was studied in this work using a representative sample. The methods of characterization were X-ray diffraction (XRD), X-ray fluorescence (XRF), particle size analysis by sieving and sedimentation, and thermal analysis. The ceramic properties were determined. A sample of commercial kaolin from Burela (Lugo, Spain), with applications in the ceramic industry, was used in some determinations for comparison purposes. The kaolin deposit has been produced by alteration of feldspar-rich rocks. This raw kaolin was applied as an additive in local manufactures of ceramics and refractories. However, there is not previous studies concerning its characteristics and firing properties. Thus, the meaning of this investigation was to conduct a scientific study on this subject and to evaluate the possibilities of application. The raw kaolin was washed for the beneficiation of the rock using water to increase the kaolinite content of the resultant material. The results indicated that the kaolinite content of the raw material was 20 wt % as determined by XRD, showing ~23 wt % of particles lower than 63 µm. The kaolinite content of the fraction lower than 63 µm was 50 wt %. Thus, an improvement of the kaolinite content of this raw kaolin was produced by wet separation. However, the kaolin was considered as a waste kaolin, with microcline, muscovite and quartz identified by XRD. Thermal analyses by Thermo-Dilatometry (TD), Differential Thermal Analysis (DTA) and Thermo-Gravimetry (TG) allowed observe kaolinite thermal decomposition, quartz phase transition and sintering effects. Pressed samples of this raw kaolin, the fraction lower than 63 µm obtained by water washing and the raw kaolin ground using a hammer mill were fired at several temperatures in the range 1000–1500 °C for 2 h. The ceramic properties of all these samples were determined and compared. The results showed the progressive linear firing shrinkage by sintering in these samples, with a maximum value of ~9% in the fraction lower than 63 µm. In general, water absorption capacity of the fired samples showed a decrease from ~18–20% at 1050 °C up to almost zero after firing at 1300 °C, followed by an increase of the experimental values. The open porosity was almost zero after firing at 1350 °C for 2 h and the bulk density reached a maximum value of 2.40 g/cm3 as observed in the ground raw kaolin sample. The XRD examination of fired samples indicated that they are composed by mullite, from kaolinite thermal decomposition, and quartz, present in the raw sample, as main crystalline phases besides a vitreous phase. Fully-densified or vitrified materials were obtained by firing at 1300–1350 °C for 2 h. In a second step of this research, it was examined the promising application of the previous study to increase the amount of mullite by incorporation of alumina (α-alumina) to this kaolin sample. Firing of mixtures, prepared using this kaolin and α-alumina under wet processing conditions, produced the increase of mullite in relative proportion by reaction sintering at temperatures higher than 1500 °C for 2 h. Consequently, a mullite refractory can be prepared using this kaolin. This processing of high-alumina refractories is favoured by a previous size separation, which increases the kaolinite content, or better a grinding treatment of the raw kaolin.

PERFECTION of PREPARATION TECHNOLOGY of the CATALYST CARRIER

Сибунит – носитель для катализатора, использующегося в различных процессах химической промышленности, в том числе и в реакции гидрирования. В настоящее время для его подготовки и проведения технологических операций используется так называемый «сухой» способ, обладающий обширными недостатками, основными из которых являются пыление, а также значительная доля ручного труда на производстве и, как следствие, большая продолжительность отдельных стадий.Предлагается использовать «мокрый» способ с применением аппаратуры роторно-пульсационного типа для подготовки носителя катализатора с целью исключения указанных недостатков.В результате проведённой работы было установлено, что активность образцов катализаторов, полученных с использованием молотковой мельницы и с применением роторно-пульсационного аппарата в реакции гидрогенолиза составила 0,606 моль/мин и 0,642 моль/мин, при выходе целевого продукта 76,15% и 80,00%, соответственно. Также определено, что доля потерь, обусловленная образованием пыли, была снижена более чем в 10 раз по сравнению с действующей технологией. Sibunit is carrying agent for the catalyst used in various processes of the chemical industry, including in hydrogenation reaction. Now for its preparation and conducting of technological operations the so-called "dry" way possessing extensive deficiencies is used, basic of which the fluffing, and also a considerable share of muscle work on manufacture and, as consequence, the big duration of separate stages are.It is offered to use a "wet" way with application of rotor-stator equipment for preparation of a catalyst carrier for the purpose of exclusion of the specified deficiencies.As a result of the spent work it has been established, that activity of the catalysts samples gained with use of the hammer mill and with application rotor-stator system in hydrogenation reaction has made 0,606 gramme-molecules/mines and 0,642 gramme-molecules/mines, at an yield of a target product of 76,15% and 80,00%, accordingly. Also it is defined, that the share of losses caused by a dust generation, it has been lowered more than in 10 times in comparison with acting technology.

Microbiological Quality of High Quality Cassava Flour Produced from Selected Varieties of Low Postharvest Physiological Deterioration Cassava (Manihot esculenta Crantz)

The microbial properties of food are important quality characteristics of food materials as it relates directly with the health of the consumer. This study examined the microbiological properties of high quality cassava flours produced from low postharvest physiological deterioration (PPD) cassava. Wholesome four varieties of yellow-fleshed Low PPD cassava and one variety of high PPD cassava were, peeled, washed, grated, pressed, pulverized, flash dried at 120 °C for 8 minutes, milled with cyclone hammer mill fitted with a screen of 250 µm aperture size, cooled and packed into high density polyethylene bag. The high quality cassava flours produced were analyzed for total viable fungal and bacteria count, fungi isolated were further characterized and identified using molecular methods. Data obtained were subjected to one way analysis of variance (ANOVA) using SPSS 25.0 and significant means were separated applying Duncan multiple range test. The mold count ranged from 1.50±0.71 - 2.50±0.71 cfu/ml, with flour produced from IITA-TMS-IBA-011371 and TMEB 419 having the lowest count while the highest was recorded in IITA-TMS-IBA-011368, respectively. The yeast count ranged from 1.00±0.00 - 2.0±0.00 cfu/ml, with flours produced from IITA-TMS-IBA-070593 and IITA-TMS-IBA-011371 having the lowest count while the highest was recorded in flour from IITA-TMS-IBA-011368, respectively. The total viable bacterial and fungal count (microbiological quality) of the flours prepared from IITA-TMS-IBA-011368, IITA-TMS-IBA-070593, IITA-TMS-IBA-011412, IITA-TMS-IBA-011371 and TMEB 419 cassava varieties were within the permissible limit of the microbial load of food allowed for human consumption according to the Standard Organization of Nigeria and CODEX alimentraius.

A Hydrometallurgical Process for Cu Recovery from Printed Circuit Boards

The current study presents an effort to develop a sustainable hydrometallurgical process for the recovery of copper from waste printed circuit boards (PCBs) to be applied at local small to medium industrial units. The process aims to separate and recover copper from filter dust produced during the crushing of PCBs using a hammer mill in a recycling facility. Due to the high plastic content in the dust (approximately 30% w/w), the metal fraction was separated gravimetrically, and the material originated consisted mainly of Cu (23.8%), Fe (17.8%), Sn (12.7%), Pb (6.3%), Zn (3.4%), Al (3.3%), Mn (1.6%), and Ni (1.5%). Prior to copper recovery, the dust was leached with HCl as a pretreatment step. During this step, more than 80% of iron, zinc, and tin were leached out. The resulting solid consisted mainly of Cu (37.6%) and Fe (10.7%), leading to a copper enrichment of around 60% in the powder. The leaching of copper was conducted in a two-step process using H2SO4 as a leaching agent with the addition of H2O2 as an oxidizing agent. The experimental conditions had low energy requirements (no heating or agitation needed). The leaching of Cu reached 98%. Despite the pretreatment step, the concentration of other metals (Fe, Zn, Ni) in the pregnant solution was too high to proceed to electrowining. Therefore, the organic solvent ACORGA M5640 was selected for the extraction of copper from the pregnant solution. The extraction was conducted in two stages at pH equilibrium 1.5, and the loaded organic phase was stripped with HCl in two steps. The strip liquor was suitable for electrowinning.

Experimental studies of in-line gasification of mechanically activated coal fuel

The 1 MW experimental stand was modernized with a scroll swirler and a crushed fuel supply system. Comparative data on combustion and gasification of coal fuel crushed in high-stress mills - disintegrator, vibrocentrifugal and hammer mill - at a stand with a thermal power of 1 MW were obtained. The experiments used coal of the Kuznetsk Basin, grade D, with technical characteristics: Wr, % = 5.4; Ar, %=22.3; Vr, % = 32.3; Qsr, MJ/kg = 20.0. Elemental analysis showed that: Cr, %=54.6; Hr, % = 4.1; Nr, % = 1.3; Sr, % = 0.5; Or = 11.8. In experiments with grinding coal on a disintegrator mill, the value of H2 = 4.5 vol.% and CO = 9.4 vol.%, when grinding in a vibro-centrifugal mill, the values of H2 = 0.6 vol.% and CO = 5.8 vol.%, when grinding in a hammer mill, the values of H2 = 0.3 vol.% and CO = 2.8 vol.%. When studying the combustion of mechanochemically treated coal samples, it was found that, all other things being equal, the gasification parameters, namely, the gas concentration and the distribution of temperature zones, depend strongly on the type of equipment used for processing. In particular, processing to approximately the same degree of fineness in mechanical mills-activators with constrained impact and in free impact mills (disintegrators) resulted in different flame parameters.

Effects of Different Pilot-Scale Milling Methods on Bioactive Components and End-Use Properties of Whole Wheat Flour

The health benefits from consumption of whole wheat products are widely recognized. This study investigated the effects of different pilot-scale milling methods on physicochemical properties, bioactive components, Chinese steamed bread (CSB), and Chinese leavened pancakes (CLP) qualities of whole wheat flour (WWF). The results indicated that WWF-1 from the reconstitution of brans processed by a hammer mill had the best CSB and CLP quality overall. WWF from entire grain grinding by a jet mill (65 Hz) contained the highest concentration of bioactive components including dietary fibers (DF) and phenolic acids. A finer particle size did not necessarily result in a higher content of phenolic antioxidants in WWF. DF contents and damaged starch were negatively correlated with CSB and CLP quality. Compromised reduced quality observed in CLP made from WWF indicated its potentially higher acceptance as a whole-grain product.

Inclusion of milled canola grain in the diet of broilers

The effect of milled canola grain (MCG) in the diet of broiler chickens, from 1 to 42 days old, on performance, organ weight, biochemical profile, and carcass yield was evaluated. A total of 660 one-day-old male Cobb® broilers were distributed in a completely randomized design with six levels of inclusion of MCG in the diet (0; 5; 10; 15; 20, and 25%), totaling six treatments with five replicates of 22 birds. The canola used for the experiment was ground using a hammer mill with a 4.5 mm sieve to obtain a DGM of 955 µm. Performance data, organ index, blood biochemical profile, carcass yields, and cut up weights were evaluated. The data were analyzed by analysis of variance (ANOVA), and when there was significance Dunnett’ test was used to compare the inclusion levels the control diet. An effect was seen on mean weights and on feed conversion based on the inclusion level of MCG in the diets. The birds that received 20 and 25% inclusion of canola in the diet presented a worse performance in relation to that of the control. For the other variables analyzed, no effect of the treatments was observed when compared with the control (p > 0.05). It was concluded that the inclusion level of MCG in the diet of up to 15% can be used without losses to the performance of birds and without influencing the metabolism of the birds.

Effect of Hammer Shape and Impact Area on Hammer Mill Performance under Different Feed Rates

The research aims to compare the performance (PC) and specific energy consumption (Spc.) of the hammer mill when using the T-hammer against the (traditional) rectangular hammer. A homemade mill with four hammers was used in experiment. 36 treatments: 2 hammer shape x 3 impact area (840, 720 and 960 mm2) x 2 feeding rates (1500 and 3000 g min-1) x 3 replicates, with completely random design. The results showed that there was no significant effect of hammer shape on PC at the feed rate of 3000 g min-1, while there was an effect at the rate of 1500 g min-1. An effect was also found for the impact area on the PC at both feeding rates and on Spc., as an inverse relationship appeared between the impact area and mill productivity at the feed rate 1500 g min-1. The area of 720 mm2 surpassed the area 480 and 960 mm2 at the rate of feeding 3000 g min-1, as it recorded 1215.65 g min-1 compared to 950.65 and 882.65 g min-1, respectively. There is effect of feeding rate on PC and Spc. The traditional hammer is recommended for simplicity of design, manufacture and performance at high feed rates compared to the T-shaped hammer.