APPLICATION OF INORGANIC REAGENTS-MODIFIERS FOR THE EXTRACTION OF SULPHUR-CONTAINING IMPURITIES IN THE FLOTATION OF GAS COALS

2021 ◽  
Vol 27 (6) ◽  
pp. 23-30
Author(s):  
N. Medyanik ◽  
◽  
E. Mullina ◽  
O. Mishurina ◽  
◽  
...  

The relevance of the research lies in the need to remove sulphur-containing compounds from coal raw materials at the lowest cost to reduce the environmental load in the areas of coal use. The object of the study is coals of the “G” brand of the Kuznetsk basin of the Kirov mine. The subject of the study is the petrographic and chemical composition of coals, the content of sulphur impurities. The aim of the study is to develop selective reagent flotation modes using inorganic reagents-modifiers. Research objectives: – to determine the petrographic and chemical composition of coals; – to conduct flotation studies using the foam flotation method; – to evaluate the effect of inorganic reagents-modifiers on the φ - potential and hydration of the coal surface; – to determine the mechanism of modifiers’ action on the depression of sulphur-containing impurities of coals. Methodology and methods of research. A complex of physical, chemical and physico-chemical research methods has been used in the work. The degree of scientific development of the topic. A promising direction for reducing sulphur-containing emissions is to increase the selectivity of the flotation process by modifying the coal surface. Results: petrographic analysis of the studied coals has showed that the main micro-component is vitrinite (85 %); chemical analysis indicates that the humidity of the coals is 2.27 %, the ash content is 17.82 %, the yield of volatile substances is 32.90 %, the mass fraction of inorganic sulphur is 0.38 %, organic sulphur is 0.43 %. A comparative analysis of qualitative and quantitative indicators of coal flotation shows that the use of non-organic reagents-modifiers can significantly increase the extraction of sulfur into flotation waste. The analysis of the kinetics of changes in the electrode potential of pyrite indicates an increase in the potential values in the presence of these reagents and a decrease in the hydration of the pyrite surface. The obtained results indicate the expediency of using inorganic salts as modifier reagents that contribute to reducing the sulfur content in coal concentrates due to the depression of pyrite-containing impurities due to an increase in the hydration of their surface

Alloy Digest ◽  
2013 ◽  
Vol 62 (9) ◽  

Abstract Böhler (or Boehler) W403 VMR is a tool steel with outstanding properties, based not only on a modified chemical composition, but on the selection of highly clean raw materials for melting, remelting under vacuum (VMF), optimized diffusion annealing, and a special heat treatment. This datasheet provides information on composition, physical properties, and elasticity. It also includes information on forming and heat treating. Filing Code: TS-721. Producer or source: Böhler Edelstahl GmbH.


2019 ◽  
Vol 46 (6) ◽  
pp. 613-620
Author(s):  
A. P. Chevychelov ◽  
P. I. Sobakin ◽  
L. I. Kuznetsova

Chemical composition of the surface water and the contents of the radionuclides 238U, 226Ra, and 222Rn in water was examined within the natural and man-made landscapes of South Yakutiya. It was demonstrated that intense water migration of these radionuclides from radioactive dump pits of the man-made landscapes of the Elkonsky uranium-ore district, which were created during the process of wide-scale exploration surveys for radioactive raw materials conducted during the last third of the 20th century, had occurred. Currently, the areas of water dissipation of 238U and 226Ra are detected at a distances of 2 km and greater from the source of the radioactive contamination along the outflow vector.


Author(s):  
Mansureh Ghavam ◽  
Afsaneh Afzali ◽  
Maria Manconi ◽  
Gianluigi Bacchetta ◽  
Maria Letizia Manca

Abstract Background Essential oil of Rosa × damascena Herrm. is one of the most valuable and important raw materials for the flavor and fragrance industry. The cultivation of this plant has ancient origins, and Kashan was one of the first mountainous regions of Iran dealing with the cultivation of R. × damascena. In this study, both chemical composition and antimicrobial activity of different rose essential oils obtained from five mountainous areas of Kashan region (Maragh, Qamsar, Sadeh, Javinan, and Kamoo) has been investigated along with the influence of the environmental conditions on these properties. Results Results showed that yield and chemical composition of essential oils obtained from Rosa × damascena were significantly affected by the collection area. In particular, the yield of oils varied from ~0.08 to ~0.132% and citronellol (36.70-9.18%), geraniol (12.82-0.47%), nonadecane (22.73-10.36%), heneicosane (31.7-11.43%), and 1-nonadecene (6.03-3.93%) have been detected as main compounds in all the plants collected, but at different concentrations depending on the collection area. The best fragrance and the highest yield were found in the oil from Kamoo area. Similarly to the chemical composition, the antimicrobial activity of the essential oils was affected by their origin, and essential oil obtained from plants collected from Kamoo area disclosed the highest antibacterial and antifungal efficacy. Its inhibition halos were 17.33±0.58 mm against Aspergillus brasiliensis, 15.67±0.58 mm against Staphylococcus aureus, and 12.33±0. 58 mm against Streptococcus pyogenes. Essential oils of R. damascena were also effective against Gram-negative Pseudomonas aeruginosa and they had a MIC value of 62.50 μg/mL irrespective of the collection area (except the oil from Javinan area). On the contrary, the highest antifungal power against Candida albicans yeast was reached using the essential oil obtained from plants collected in Javinan region (MIC and MBC ~62.50 μg/mL). Conclusions Overall results underline the influence of environmental conditions of the different areas of Kashan region, on the chemical composition of and antimicrobial activity of the essential oils of Rosa × damascena. In addition, results disclosed that Kamoo seemed to be the most suitable area for the competitive cultivation of R. × damascena to the intensive production of aromatic flower oil and natural antimicrobial essential oils.


Geosciences ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 36
Author(s):  
Vayia Xanthopoulou ◽  
Ioannis Iliopoulos ◽  
Ioannis Liritzis

The present study deals with the characterization of a ceramic assemblage from the Late Mycenaean (Late Helladic III) settlement of Kastrouli, at Desfina near Delphi, Central Greece using various analytical techniques. Kastrouli is located in a strategic position supervising the Mesokampos plateau and the entire peninsula and is related to other nearby coeval settlements. In total 40 ceramic sherds and 8 clay raw materials were analyzed through mineralogical, petrographic and microstructural techniques. Experimental briquettes (DS) made from clayey raw materials collected in the vicinity of Kastrouli, were fired under temperatures (900 and 1050 °C) in oxidizing conditions for comparison with the ancient ceramics. The petrographic analysis performed on thin sections prepared from the sherds has permitted the identification of six main fabric groups and a couple of loners. The aplastic inclusions recognized in all fabric groups but one confirmed the local provenance since they are related to the local geology. Fresh fractures of representative sherds were further examined under a scanning electron microscope (SEM/EDS) helping us to classify them into calcareous (CaO > 6%) and non-calcareous (CaO < 6%) samples (low and high calcium was noted in earlier pXRF data). Here, the ceramic sherds with broad calcium separation are explored on a one-to-one comparison on the basis of detailed mineralogical microstructure. Moreover, their microstructure was studied, aiming to estimate their vitrification stage. The mineralogy of all studied samples was determined by means of X-ray powder diffraction (XRPD), permitting us to test the validity of the firing temperatures revealed by the SEM analysis. The results obtained through the various analytical techniques employed are jointly assessed in order to reveal potters’ technological choices.


2012 ◽  
Vol 67 (10) ◽  
pp. 961-975 ◽  
Author(s):  
Markus Hölscher ◽  
Christoph Gürtler ◽  
Wilhelm Keim ◽  
Thomas E. Müller ◽  
Martina Peters ◽  
...  

With the growing perception of industrialized societies that fossil raw materials are limited resources, academic chemical research and chemical industry have started to introduce novel catalytic technologies which aim at the development of economically competitive processes relying much more strongly on the use of alternative carbon feedstocks. Great interest is given world-wide to carbon dioxide (CO2) as it is part of the global carbon cycle, nontoxic, easily available in sufficient quantities anywhere in the industrialized world, and can be managed technically with ease, and at low cost. In principle carbon dioxide can be used to generate a large variety of synthetic products ranging from bulk chemicals like methanol and formic acid, through polymeric materials, to fine chemicals like aromatic acids useful in the pharmaceutical industry. Owing to the high thermodynamic stability of CO2, the energy constraints of chemical reactions have to be carefully analyzed to select promising processes. Furthermore, the high kinetic barriers for incorporation of CO2 into C-H or C-C bond forming reactions require that any novel transformation of CO2 must inevitably be associated with a novel catalytic technology. This short review comprises a selection of the most recent academic and industrial research developments mainly with regard to innovations in CO2 chemistry in the field of homogeneous catalysis and processes.


Author(s):  
Е.Е. Ульянченко

Исследовано влияние приема прорезания средней жилки на основные качественные показатели табачного сырья. Исследования проводили на листьях основных сортотипов табака Трапезонд и Остролист по массовым ломкам. Прорезание жилки осуществляли на инновационном оборудовании экспериментальном образце линии подготовки листьев табака к сушке ЛПТС360 (ВНИИТТИ, Краснодар). Качество табачного сырья с прорезанной жилкой определяли по товарным сортам, технологическим и курительным свойствам, химическому составу по методикам лабораторного контроля ВНИИТТИ. Инновационный способ подготовки табака к сушке в едином потоке с применением технологического оборудования, включающего прорезатель, выявил положительный технологический результат. Установлена эффективность приема прорезания средней жилки: срок естественной сушки листьев с прорезанной жилкой сократился в 2,5 раза выход 1го товарного сорта сырья составил 74,60 87,93 выход волокна сырья с прорезанной жилкой превышает минимальное значение технологических норм (75) в 1,15 1,26 раз условный расход сырья на единицу курительных изделий меньше норматива на 6 25 улучшен основной показатель химического состава табачного сырья (число Шмука) в 1,6 4,6 раза у сортотипа Трапезонд, в 1,2 1,5 раза у сортотипа Остролист дегустационные свойства сырья не ухудшились. Инновационный способ подготовки листьев табака к сушке, включающий прием прорезания средней жилки, рекомендуется для применения в производстве табачного сырья. The influence of middle vein cutting method on the main quality indicators of tobacco raw materials is studied. Studies were carried out on the leaves of the main varieties of tobacco Trapezond and Ostrolist, on mass breakdowns. Vein cutting was carried out on the innovative equipment of the line of preparation of tobacco leaves for drying LPTS360 (GNU VNIITTI RAA, Krasnodar). The quality of tobacco raw materials with a cut vein was determined by commercial grades, technological and Smoking properties, chemical composition in accordance with the methods VNIITTI. An innovative method of preparing tobacco for drying in a single stream with the use of technological equipment, including a cutter, revealed a positive technological result. The period of natural drying of leaves with cut veins decreased by 2,5 times. The yield of the 1st commercial grade of raw materials was 74,60 87,93. The output of the fiber raw material with cut vein exceeds the minimum value of technological norms (75) in 1,15 1,26 times. Conditional consumption of raw materials per unit of Smoking products is less than the norm by 6 25. The method of cutting the middle vein of the leaves improves the main indicator in the chemical composition of tobacco raw materials (Schmuck ratio) 1,6 4,6 times in the variety Trapezond and 1,2 1,5 times in the variety Ostrolist. The tasting properties of raw materials have not deteriorated. Analysis of raw material quality indicators showed that the innovative method of cutting the middle vein is effective and recommended for use in the production of tobacco raw materials.


Author(s):  
О.В. ПРИСТУПКО ◽  
Л.Я. РОДИОНОВА

Разработаны рецептуры напитков функционального назначения из овощных соков с добавлением концентрата из пророщенного зерна полбы Руно . Исследована комплексообразующая способность (КС) напитка при оптимальном соотношении белка и пектина. Определен химический состав используемого сырья и энергетическая ценность готовых напитков. Установлено содержание в 100 г разработанного напитка, образец 1 и 2 соответственно: сухих веществ 8,6 и 7,2 пектиновых веществ 1,80 и 1,79 белков 3,46 и 3,40 г углеводов 10,46 и 7,87 г жиров по 0,14 г. КС образцов 1 и 2 соответственно (58 0,1) и (56 0,2) мг Pb2/мл значение pH 5,1 0,3 и 5,3 0,4. Разработанные овощные соки с мякотью, обогащенные пророщенным зерном полбы Руно , могут быть рекомендованы в качестве овощных напитков функциональной направленности. Recipes of functional drinks from vegetable juices with the addition of concentrate from sprouted grain of spelt Runo have been developed. The complexing ability of the drink with the optimal ratio of protein and pectin was studied. Was determined the chemical composition of the raw materials used and the energy value of the finished beverages. The content of 100 g of developed drinks, the samples 1 and 2, respectively: dry solids 8,6 and 7,2 pectin substances 1,80 and 1,79 proteins 3,46 and 3,40 g carbohydrates 10,46 and 7,87 g of fats in each sample of 0,14 g. The complexing ability of samples 1 and 2, respectively (58 0,1) and (56 0,2) mg Pb2/ml the pH value, respectively 5,1 0,3 and 5,3 0,4. Developed vegetable juices with pulp, enriched with sprouted grain of spelt Runo , can be recommended as vegetable drinks of a functional orientation.


2021 ◽  
Vol 9 (16) ◽  
pp. 57-68
Author(s):  
Halyna Voloshchuk ◽  

Subject of research – sugar content in rye bread with fractionally defatted flour from walnuts, pumpkin seeds, sesame and Jerusalem artichoke powder. The purpose – to investigate the chemical composition of sugars in flour from oilseed meal and to explain the impact of new raw materials upon the sugar content in bread made from rye flour. Materials and methods. For the production of pilot of bread used: rye flour; fermented rye malt; table salt; drinking water; ready liquid rye sourdough (composition: Lactobacillus plantarum 30, L .casei 26, L. fermenti 34, L .brevis and Saccharomyces minor "Chernorichenskaya", S. cerevisiae L1); fractionally defatted flour from walnuts, pumpkin seeds and sesame produced by PE "Research and Production Company "Elitfito"; Jerusalem artichoke powder "Dar". The dough was prepared in a three-phase way: liquid sourdough – saccharified choux – dough. Jerusalem artichoke powder and oilseed meal were added to the dough. The chemical composition of sugars in raw materials and bread was determined by high-performance liquid chromatography. The effect of fractionally defatted flour on the course of processes in rye dough was performed on a farinograph and amylograph of Brabender. The intensity of gas formation of the dough was determined on the device AG-1. Changes in the crystal structure of the bread crumb were performed using X-ray phase analysis on the device DRON UM-1 in the range of angles 2θ from 5 to 60 degrees. Results. It is established that the share of sugars in flour from oilseed meal is 2 ... 8 times higher than the content of sugars in rye flour. The content of sugars in fractionally defatted flour from walnuts is 43.0 %, from pumpkin seeds – 14.2 %, from sesame – 12.8% by weight of dry matter. Up to 80% of all sugars in fractionally defatted flour are sucrose and maltose. The ratio of fructose to glucose in fractionally defatted flour from walnuts is 1:1.25; from pumpkin seeds – 1:0.73; of sesame seeds – 1:0.5. The addition of 7.0 % fractionally defatted flour mixed with 3 % of the Jerusalem artichoke powder reduces the mass fraction of sugars in bread compared to the bread made with Jerusalem artichoke only. It has been studied that fractionally defatted flour from walnuts, pumpkin seeds and sesame reduces the hydrolytic decomposition of rye flour starch and promotes the process of fermentation of sugars. Scope. A mixture of fractionally defatted flour from oilseed meal in the amount of 7 % should be used for the production of bread from rye flour with 3 % Jerusalem artichoke powder to the mass fraction of flour to reduce the content of high glycemic starch sugars.


2015 ◽  
Vol 51 (2) ◽  
pp. 143-151 ◽  
Author(s):  
K.X. Jiao ◽  
J.L. Zhang ◽  
Z.J. Liu ◽  
Y.G. Zhao ◽  
X.M. Hou

A type of carbon composite brick was produced via the microporous technique using natural flack graphite, ?-Al2O3 and high-quality bauxite chamotte (Al2O3?87 mass%) as raw materials with fine silicon powder as additive. The composition and microstructure of the obtained carbon composite were characterized using chemical analysis, XRD and SEM with EDS. The high temperature properties of thermal conductivity, oxidization and corrosion by molten slag and hot metal of the composite were analyzed. Based on these, the type of carbon composite brick worked in a blast furnace hearth for six years was further sampled at different positions. The protective layer was found and its chemical composition and microscopic morphology were investigated. It is found that the carbon composite brick combines the good properties of both the conventional carbon block and ceramic cup refractory. The protective layer near the hot face consists of two separated sublayers, i.e. the slag layer and the carbon layer. A certain amount of slag phase is contained in the carbon layer, which is caused by the reaction of coke ash with the refractory. No obvious change in the chemical composition of the protective layer along the depth of the sidewall is found. This work provides a useful guidance for the extension of the lifetime of blast furnace hearths.


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