WATERPROOF ANTI-EXPLOSIVE POWDERS FOR COAL MINES

2014 ◽  
Vol 59 (1) ◽  
pp. 169-178
Author(s):  
Bronisław Buczek ◽  
Elżbieta Vogt
Keyword(s):  
Thermal Decomposition ◽  
Stearic Acid ◽  
Mining Industry ◽  
Vapour Phase ◽  
Point Of View ◽  
Raw Material ◽  
Limestone Powder ◽  
Powder Layer ◽  
Vapour Adsorption ◽  
Lime Powder

Abstract Limestone powder characterized by hydrophobic properties is used as an anti-explosive agent in coal mining industry. Unfortunately, the standard method of producing such powder by milling limestone with stearic acid is practically unprofitable in many modernized quarries and plants, and sometimes literally impossible due to the introduction of technological changes and implementation of modern mills. Then new methods of hydrophobization of limestone surfaces ought be searched. In the work two methods hydrophobization: from the stearic acid vapour phase and from silicone solutions are proposed. Lime dust from the Czatkowice Quarry of Lime was used as a raw material during investigations. It is a good agent for research because it is possible to compare the properties of samples modified in this work to the properties of anti-explosive lime powder (Polish Standard, 1994) used in mining industry in Poland. The first technique of limestone powder hydrophobization was carried out in an apparatus of own design (Vogt, 2008, 2011), and it consisted in free sedimentation of the powder layer dispersed by stearic acid vapour in powder counter current flow. The second way of modification consisted in mixing in the evaporating dish substrates: limestone powder and dope - silicone solution - Sarsil® H-15 (Vogt & Opaliński, 2009; Vogt & Hołownia, 2010). Evaluation of properties so-obtained waterproof powders was carried out according to the Polish Standard, as well as using original powder determination ways, with the Powder Characteristic Tester (Index tables, Tablets & Capsules, 2005). Moreover water vapour adsorption isotherms were obtained and the thermal decomposition of powder was made. All modified samples acquired the hydrophobic character. Therefore we can state that the both proposed methods of hydrophobization of the limestone powder are useful. The parameters obtained with the use of Powder Characteristics Tester enable us to make a characterization of limestone properties not only as a water resistant material but also from the cohesion point of view. On the base of TG, DTG or DTA and EGA curves for all investigated materials was stated that the character of the thermal decomposition of modified samples is the same as this one for raw powder, what is profitable for application of hydrophobized powders as an anti-explosive agent.

Substituent Effects on the Thermal Decomposition of Phosphate Esters on Ferrous Surfaces

2019 ◽  
Author(s):  
James Ewen ◽  
Carlos Ayestaran Latorre ◽  
Arash Khajeh ◽  
Joshua Moore ◽  
Joseph Remias ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Film Formation ◽  
Substituent Effects ◽  
Vapour Phase ◽  
Industrial Applications ◽  
Phosphate Esters ◽  
Antiwear Additives ◽  
Formation Mechanisms ◽  
Phosphate Ester ◽  
Wide Range

<p>Phosphate esters have a wide range of industrial applications, for example in tribology where they are used as vapour phase lubricants and antiwear additives. To rationally design phosphate esters with improved tribological performance, an atomic-level understanding of their film formation mechanisms is required. One important aspect is the thermal decomposition of phosphate esters on steel surfaces, since this initiates film formation. In this study, ReaxFF molecular dynamics simulations are used to study the thermal decomposition of phosphate esters with different substituents on several ferrous surfaces. On Fe<sub>3</sub>O<sub>4</sub>(001) and α-Fe(110), chemisorption interactions between the phosphate esters and the surfaces occur even at room temperature, and the number of molecule-surface bonds increases as the temperature is increased from 300 to 1000 K. Conversely, on hydroxylated, amorphous Fe<sub>3</sub>O<sub>4</sub>, most of the molecules are physisorbed, even at high temperature. Thermal decomposition rates were much higher on Fe<sub>3</sub>O<sub>4</sub>(001) and particularly α-Fe(110) compared to hydroxylated, amorphous Fe<sub>3</sub>O<sub>4</sub>. This suggests that water passivates ferrous surfaces and inhibits phosphate ester chemisorption, decomposition, and ultimately film formation. On Fe<sub>3</sub>O<sub>4</sub>(001), thermal decomposition proceeds mainly through C-O cleavage (to form surface alkyl and aryl groups) and C-H cleavage (to form surface hydroxyls). The onset temperature for C-O cleavage on Fe<sub>3</sub>O<sub>4</sub>(001) increases in the order: tertiary alkyl < secondary alkyl < primary linear alkyl ≈ primary branched alkyl < aryl. This order is in agreement with experimental observations for the thermal stability of antiwear additives with similar substituents. The results highlight surface and substituent effects on the thermal decomposition of phosphate esters which should be helpful for the design of new molecules with improved performance.</p>

Calculation of the Glaze Recipe for Porcelain Feldspar Products Based on their Molecular Formula Rationalization

2008 ◽  
Vol 59 (2) ◽  
pp. 129-134
Author(s):  
Ion Teoreanu ◽  
Roxana Lucia Dumitrache ◽  
Stefania Stoleriu
Keyword(s):  
Raw Materials ◽  
Computer Programs ◽  
Point Of View ◽  
Raw Material ◽  
Easy Access ◽  
Molecular Formula ◽  
Design Equation ◽  
Material Sources

Any change of the raw material sources for glazes, economically, ecologically motivated, and also from the glaze quality point of view, is conditioned by the molecular formula rationalization and by the variation limits of the molecular formula, respectively. The proper glaze compositions are placed within their limit variation intervals with optimized processing and utilization properties. For this purpose, the rationalization criteria and procedures of molecular formulas are summarized in the present paper, as well as the results referring to their rationalization obtained in the authors� previous work. Thus, one starts from a base of raw materials that are selected, usable and also accessible for the design and producing of the glazes. On these bases the groundwork and the design equation for the glaze recipes are developed, exemplified for a single glaze. For an easy access to results, computer programs are used for an easy access to results.

scholarly journals Potential of Probiotic Frozen Blackcurrant Products: Consumer Preference, Physicochemical Characterization, and Cell Viability

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 792
Author(s):  
Kati Väkeväinen ◽  
Noora Rinkinen ◽  
Roosa-Maria Willman ◽  
Jenni Lappi ◽  
Kaisa Raninen ◽  
...  
Keyword(s):  
Storage Time ◽  
Physicochemical Characterization ◽  
Consumer Preference ◽  
Nutritional Composition ◽  
Point Of View ◽  
Raw Material ◽  
Frozen Food ◽  
High Viability ◽  
Food Applications

Blackcurrant is a healthy, affordable, and traditionally gardened berry that, thus far, has been underused in food applications. From the consumers’ point of view, the acidic taste of blackcurrants is a challenge; therefore, these berries have mainly been utilized for sugary juice production. This research study aimed to develop a frozen vegan blackcurrant product with pleasant sensory properties and potential probiotic function. A candidate probiotic, Lactoplantibacillus plantarum Q823, was used in the manufacturing process. The physicochemical properties, nutritional composition, and consumer preference for the developed product were assessed, as was the viability of L. plantarum Q823 during storage time and in an in vitro gastrointestinal model. Consumers (n = 71) perceived the developed product to be pleasant. L. plantarum Q823 had high viability counts (log colony forming units (cfu) g−1 7.0 ± 0.38) in the final product, although the viability of L. plantarum Q823 during storage time needs to be enhanced to obtain a probiotic product. Thus, within an optimized formulation, blackcurrant berries represent a potential raw material for functional frozen food products.

scholarly journals Characterization and Evaluation of Salvia hispanica L. and Salvia columbariae Benth. Varieties for Their Cultivation in Southwestern Germany

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2012
Author(s):  
Samantha Jo Grimes ◽  
Filippo Capezzone ◽  
Peteh Mehdi Nkebiwe ◽  
Simone Graeff-Hönninger
Keyword(s):  
Seed Mass ◽  
Point Of View ◽  
Raw Material ◽  
Salvia Hispanica ◽  
Environmentally Sustainable ◽  
Chia Seed ◽  
Increasing Demand ◽  
Salvia Hispanica L ◽  
Reported Data ◽  
Seed Yields

Rising consumer attraction towards superfoods and the steadily increasing demand for healthy, environmentally sustainable, and regionally produced food products has sharpened the demand for chia. Over the course of 4 years, two early flowering chia varieties belonging to Salvia hispanica L., and Salvia columbariae Benth. Species were identified to complete their phenological development and, therefore, able to reach maturity under a photoperiod >12 h, thus enabling the cultivation of chia in central Europe—more specifically, in southwestern Germany—consistently for the first time. Results obtained by the conducted field trial in 2018 showed that chia seed yields and thousand-seed mass ranged from 284.13 to 643.99 kg ha−1 and 0.92 to 1.36 g, respectively. Further, the statistical analyses showed that the protein content of the cultivated chia varieties ranged from 22.14 to 27.78%, the mucilage content varied from 10.35 to 20.66%, and the crude oil content amounted up to 28.00 and 31.73%. Fatty acid profiles were similar to previously reported data with α-Linolenic acid being the most prominent one, ranging from 60.40 to 65.87%, and we obtained ω6:ω3 ratios between 0.2 and 0.3. In conclusion, chia could represent a promising raw material from a nutritional point of view, while being able to diversify the local food basis of southwestern Germany.

scholarly journals Methodology for the quantification of concrete sustainability

2018 ◽  
Vol 174 ◽  
pp. 01006 ◽  
Author(s):  
Břetislav Teplý ◽  
Tomáš Vymazal ◽  
Pavla Rovnaníková
Keyword(s):  
Decision Making ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Environmental Impact ◽  
Service Life ◽  
Circular Economy ◽  
Point Of View ◽  
Raw Material ◽  
Load Bearing Capacity ◽  
Sustainability Management

Efficient sustainability management requires the use of tools which allow material, technological and construction variants to be quantified, measured or compared. These tools can be used as a powerful marketing aid and as support for the transition to “circular economy”. Life Cycle Assessment (LCA) procedures are also used, aside from other approaches. LCA is a method that evaluates the life cycle of a structure from the point of view of its impact on the environment. Consideration is given also to energy and raw material costs, as well as to environmental impact throughout the life cycle - e.g. due to emissions. The paper focuses on the quantification of sustainability connected with the use of various types of concrete with regard to their resistance to degradation. Sustainability coefficients are determined using information regarding service life and "eco-costs". The aim is to propose a suitable methodology which can simplify decision-making in the design and choice of concrete mixes from a wider perspective, i.e. not only with regard to load-bearing capacity or durability.

DIRECTIONS FOR ENHANCING THE DEVELOPMENT OF CITRUS FRUIT GROWING IN AZERBAIJAN

2021 ◽  
Vol 1 (10) ◽  
pp. 167-173
Author(s):  
Nurida Аlish Gasimova ◽  
Keyword(s):  
Citrus Fruit ◽  
Economic Importance ◽  
Point Of View ◽  
Raw Material ◽  
Current State ◽  
Citrus Production ◽  
Fruit Growing

The increase in citrus production is of particular economic importance both from the point of view of meeting the demand of the population for these products, and from the point of view of its use as an industrial raw material. The article studies and analyzes the current state of citrus cultivation in Azerbaijan, the possibilities of increasing their production; relevant suggestions and recommendations are made.

scholarly journals USE OF SLUDGE FROM SANITARY SEWAGE TREATMENT PLANTS (S.T.P) AND THEIR USE AS RAW MATERIAL IN THE MANUFACTURE OF BRICKS

2019 ◽  
Vol 16 (33) ◽  
pp. 823-840
Author(s):  
M. K. TARABAI ◽  
S. G. de AZEVEDO
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Sewage Treatment ◽  
Point Of View ◽  
Test Method ◽  
Raw Material ◽  
Environmental Preservation ◽  
Ceramic Block ◽  
Environmental Requirements ◽  
The One

This paper discusses a possible solution regarding the final disposal of sludge from Sanitary Sewage Treatment Stations (ET), aiming at environmental preservation. The solid waste generated after the wastewater treatment processes is highly contaminating and detrimental to the area in which it is deposited. Given this, the use of sludge with the application of reuse techniques becomes pertinent, both from the economic point of view and from the ecological point of view. By replacing the use of aggregates from mineral deposits, the main clay raw material in the manufacture of ceramic products (Vieira, 2000), by the treated sludge of WWTP we will save on the sources of granular materials. Aiming its reintegration to the production cycle through the introduction of sludge as raw material incorporated in the ceramic mass in the manufacture of hollow bricks, the viability of use was verified through performance analysis, compared to the control brick made of pottery, without the addition of sludge. Specimens were prepared with three types of samples: 90% clay and 10% sludge; 80% clay and 20% sludge; 70% clay and 30% sludge. Mass loss, water absorption index and compressive strength tests were performed. As for the tests, the specimens with 10% and 20% of sludge were the ones that had better adaptation to the technical requirements, but because it is a larger volume of the residue for the application of reuse techniques, the brick with 20% sludge dosage. is the most suitable. NBR7.171, November 1992: Ceramic Block for masonry; Specification NBR 6.461, June 1983: Masonry Ceramic Block - Compressive Strength Check: Test Method; NBR 8.947, November 1992: Ceramic Tile- Determination of Mass and Water Absorption: Test Method. As for the tests, the specimen with 20% of sludge was the one that had the best adaptation to technical and environmental requirements. The present article approaches a possible solution regarding the destination of the sludge coming from Sanitary Sewage Treatment Stations, aiming at environmental preservation. Aiming at its reintegration into the productive cycle through applications of reuse techniques, the sludge became raw material when the ceramic mass was incorporated into the brick fabrication. Three types of samples were elaborated: 90% of clay and 10% of mud; 80% clay and 20% sludge; 70% clay and 30% sludge. As for the tests, the test specimen with 20% of sludge was the one that had more adequacy to the technical and environmental requirements.

scholarly journals BIA, DPA, MBTA and DMA as Vapour Phase Corrosion Inhibitors for Mild Steel under Different Atmospheric Conditions

2013 ◽  
Vol 20 ◽  
pp. 52-66
Author(s):  
Harish Kumar ◽  
Vikas Yadav
Keyword(s):  
Mild Steel ◽  
Corrosion Inhibitors ◽  
Inhibition Efficiency ◽  
Salt Spray ◽  
Vapour Phase ◽  
Raw Material ◽  
Atmospheric Conditions ◽  
Sem Images ◽  
Corrosion Inhibition Efficiency ◽  
Diphenyl Amine

Mild steel is widely used as main raw material in fabrication of equipment, chief material of construction and as weapons. During its storage and transportation conditions, it comes in contact with aggressive environment which leads to decrease in mechanical strength and loss in useful properties. Four different vapor phase corrosion inhibitors (VPCIs) i.e. Benzaimidazole (BIA), Diphenyl amine (DPA), 2-mercapto benzothiazole (MBTA) and N,N-dimethyl aniline (DMA) were tested under different atmospheric conditions at 40 °C by Weight Loss, Eschke test, Salt Spray, SO2 test and SEM techniques. All the four VPCIs show good corrosion inhibition efficiency i.e. 65-96 %. The results obtained from all the four corrosion experiments were supported by SEM images.

scholarly journals LOW- GRADE STRUCTURES OF NOBLE AND NON- FERROUS METALS AND METHODS OF THEIR SELECTIVE SEPARATION

2021 ◽  
Vol 13 (2) ◽  
pp. 161-169
Author(s):  
Tatyana ALEXANDROVA ◽  
◽  
Anastasia AFANASOVA ◽  
Nadezhda NIKOLAEVA ◽  
◽  
...  
Keyword(s):  
Development Strategy ◽  
Raw Materials ◽  
Close Association ◽  
Mining Industry ◽  
Raw Material ◽  
Free Form ◽  
Mineral Matter ◽  
Low Grade ◽  
Rare Metals ◽  
Flotation Process

There is a worldwide trend of increasing the share of extraction and processing of low-grade minerals, but their extraction and processing volumes are still low. There are several reasons for this: high mining and transportation costs, imperfect techniques and technological difficulties in enrichment and processing of refractory and low-quality minerals. Due to the depletion of reserves of easily beneficiated raw materials and to compensate for the growing shortage of high-quality minerals, the Russian mining industry development strategy provides for the involvement of new and unconventional types of deposits into production. Examples of such deposits are deposits of carbonaceous raw materials (black shale, refractory sulphide carbon-bearing ores, impactites, etc.) containing carbon of varying degrees of metamorphism. On the basis of the most modern mineralogical, physical, nuclear and chemical methods of research of composition, structure and properties of the carbonaceous raw materials at the micro- and nanolevel, the composition of the productive mineral matter, physical, chemical and thermodynamic laws of separation of valuable mineral components and the basic technological processes to obtain the finished product for valorization of the unconventional carbonaceous mineral raw materials were determined with maximum reliability. One of the possible reasons of difficulty of beneficiation of carbonaceous raw materials is the fine phenocrysts in graphite which can be solved by using the flotation process. Contrast of surface properties of minerals with similar technological properties can be increased by application of different energy effects (MEMI, MIO, microwave, electrochemical treatment etc.) at successive stages of raw material transformation, regulation of pulp conditioning conditions (duration and intensity of agitation, heat treatment of pulp) as well as by development and application of selective reagent regimes. The special feature of flotation as a method of extraction of noble and rare metals is the ability to extract valuable metals not only in their native free form, but also in close association with sulphides and carbon. Flotation with the use of intensifying influences made it possible to transfereven low-sized structures of noble and rare metals, which are not extracted by conventional methods of cyanidation, gravitation enrichment and amalgamation, into the concentrate. One of the ways to increase the efficiency of the flotation process is preliminary modification of the additive which is introduced in addition to the main reagents of the sinter - “carrier material”.

scholarly journals THE STATE AND PROGRESS OF OILSEEDS MARKET AND FOODS OF THEIR PROCESSING TRENDS ARE IN UKRAINE

2018 ◽  
Vol 20 (1(66)) ◽  
pp. 44-52 ◽  
Author(s):  
P.O ANTONYUK ◽  
V.M. LISYUK
Keyword(s):  
Structural Changes ◽  
Export Price ◽  
Processing Condition ◽  
World Market ◽  
Point Of View ◽  
Raw Material ◽  
Home Production ◽  
Yield Production ◽  
Production Capacities ◽  
Practical Recommendations

Topicality. Actuality of problem of oilseeds market and foods of their processing development increases inconnection with the necessity of maintenance of existent volumes and leading positions of Ukraine in the world market, and also increases of efficiency of functioning component the integrated market. Aim and tasks. The aim of the article is an estimation of existent oilseeds market and foods of their processing condition, development of practical recommendations, both on the height of production and sales volumes and to efficiency in the conditions of action of the free trading with European Union. Research results. A oilseed market and foods of their processing analysis is conducted from the point of view of volume and structure as oilseeds raw material so vegetable oil. Measures are offered on the improvement of structure at the market of vegetable oils, meaning the heightof stake of soy-bean and rape oil. These measures areaimed at limitation of export of oilseeds raw material, especially soy and rape, and also all types of cake. Therow of measures of the custom adjusting is offered with the purpose of increase of home production and export of products with a greater valueadded. Conclusions. Strategic directions of oilseeds market and foods of their processing development include measures on limitation of export of raw material and on the increase of export of products with a greater valueadded. Keywords: world export, crop rotation, profitability, middle export price, export profit yield, production capacities, unrefined oil, structural changes

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