scholarly journals A POSSIBILITY OF SYNTHESIS OF HIGH-ALUMINA CEMENTS FROM DIFFERENT RAW MATERIALS

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Dragica Lazić ◽  
Dragana Kešelj ◽  
Jelena Penavin Škundrić ◽  
Ljubica Vasiljević ◽  
Janko Mikić

Calcium aluminate cements with high Al2O3 content are synthesized from different raw materials. Raw materials used in the synthesis include: lime, tricalcium aluminate hexahydrate, aluminum hydroxide and sodium aluminate solution. The preparation of raw material mixture for sintering was performed in two ways: the first method of preparation of a raw material mixture was by mixing powdered components (Al(OH)3 and CaO, Al(OH)3 and 3CaO·Al2O3·6H2O), another method included stirring into the liquid phase (NaAlO2, CaO and Al (OH)3) for a certain period of time at the temperature of 90°C, whereby the obtained solid phase was used as raw material for sintering. Chemical and mineralogical analysis (XRD) were performed on the cements obtained in synthesis. Based on chemical analysis it was concluded that the cements obtained were CAC 70 and CAC 80, as the Al2O3 content in these cements ranged from 70 to 75.37% for the first type, while the second type had a range of 77-79%. XRD analysis showed that the dominated minerals in cement CAC 70 were CaO• Al2O3 and CaO • 2Al2O3, and in cement CAC 80, mineral CaO • 2Al2O3, which is consistent with the findings published on these cements.

Author(s):  
Z. R. Kadyrova ◽  
R. Kh. Pirmatov ◽  
A. A. Eminov

The results of studies of promising raw material resources of Uzbekistan (enriched kaolins, bauxite-like rock, highalumina waste from the gas processing industry) to obtain high-alumina aggregates are presented. It is established that these raw materials in terms of their physico-chemical indicators meet the requirements for aluminosilicate and high-alumina materials used in metallurgical units. Ref. 13. Tab. 3.


Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2237 ◽  
Author(s):  
P. R. Sarika ◽  
Paul Nancarrow ◽  
Abdulrahman Khansaheb ◽  
Taleb Ibrahim

Phenol–formaldehyde (PF) resin continues to dominate the resin industry more than 100 years after its first synthesis. Its versatile properties such as thermal stability, chemical resistance, fire resistance, and dimensional stability make it a suitable material for a wide range of applications. PF resins have been used in the wood industry as adhesives, in paints and coatings, and in the aerospace, construction, and building industries as composites and foams. Currently, petroleum is the key source of raw materials used in manufacturing PF resin. However, increasing environmental pollution and fossil fuel depletion have driven industries to seek sustainable alternatives to petroleum based raw materials. Over the past decade, researchers have replaced phenol and formaldehyde with sustainable materials such as lignin, tannin, cardanol, hydroxymethylfurfural, and glyoxal to produce bio-based PF resin. Several synthesis modifications are currently under investigation towards improving the properties of bio-based phenolic resin. This review discusses recent developments in the synthesis of PF resins, particularly those created from sustainable raw material substitutes, and modifications applied to the synthetic route in order to improve the mechanical properties.


Cerâmica ◽  
2013 ◽  
Vol 59 (351) ◽  
pp. 473-480 ◽  
Author(s):  
K. C. P. Faria ◽  
J. N. F. Holanda

The sugarcane industry generates huge amounts of sugarcane bagasse ashes (SCBA). This work investigates the incorporation of a SCBA waste as an alternative raw material into a clay body, replacing natural clay material by up to 20 wt.%. Clay ceramic pieces were produced by uniaxial pressing and fired at temperatures varying from 700 to 1100 ºC. The technological properties of the clay ceramic pieces (linear shrinkage, apparent density, water absorption, and tensile strength) as function of the firing temperature and waste addition are investigated. The phase evolution during firing was followed by X-ray diffraction. The results showed that the SCBA waste could be incorporated into red ceramics (bricks and roofing tiles) in partial replacement for natural clay material. These results confirm the feasibility of valorisation of SCBA waste to produce red ceramic. This use of SCBA can also contribute greatly to reducing the environmental problems of the sugarcane industry, and also save the sources of natural raw materials used in the ceramic industry.


2021 ◽  
Vol 12 (3) ◽  
pp. 111-118
Author(s):  
N. Yu. Tereshchenko ◽  
◽  
O. Yu. Kursenko ◽  
O. I. Khyzhan ◽  
O. I. Khyzhan ◽  
...  

The paper presents the methodology of preparation of samples of oilseeds, lettuce, apples for research by chromatographic control of xenobiotics of the following chemical groups of pesticides: benzimidazole derivatives, anilinopyrimidine derivatives, bipyridylium derivatives. The implementation of the following processes is considered: homogenization of the sample, purification of the extract by solid-phase or liquid-liquid extraction, obtaining a plant extract, obtaining an extract of analytes. For fine-grained homogenized samples of sunflower seeds, the optimal ratio of raw material -extragent is 1:20, for pasty homogenized samples of apple fruit - 1:10, for liquid samples of homogenized lettuce - 1: 5. Analysis of the distribution of xenobiotics in the system octane/water, the dipole moment of solvents allowed to determine the extractants that are able to dissolve and remove xenobiotics from raw materials. It was found that a mixture of acetonitrile and methanol (4: 1) should be used to remove benzimidazole derivatives and anilinopyrimidine derivatives, bipyridylium derivatives are best extracted with methanolic trifluoroacetic acid (9.5: 0.5). Quantitative analysis of xenobiotics content in extracts obtained from samples artificially enriched with xenobiotics was performed. The most complete xenobiotics were removed from samples of plant products containing traces of fat. The most difficult process of sample preparation is the process of obtaining sunflower seed extract. The content of xenobiotics in extracts obtained from samples artificially enriched in analytes is influenced by the temperature at which the process takes place and the duration of extraction. Based on the chemical composition of the sample matrix and the list of analytes, the conditions of the variable component of the methodology are proposed: obtaining plant extract under the action of selective solvents, homogenized raw material-solvent with constant stirring of the extraction system at 180-200 rpm, or under the action of ultrasonic vibrations with a frequency of 37 kHz from 4°C to 25°C for 5-25 minutes. The control of the qualitative and quantitative composition of the studied plant extracts and analyte extracts was investigated by the methods of high-performance liquid and gas chromatography (liquid and gas) with mass-selective detectors.


Author(s):  
Patrick Degryse ◽  
Dennis Braekmans

Petrography has developed into an indispensable tool for ceramic fabric analysis, specifically studying the mineralogical and textural composition of ceramic objects. Petrography is a technique commonly used in geology to describe and classify rocks. Ceramic petrography studies clay-based archaeological or historical materials. Using a polarizing light microscope (PLM) in ceramic studies, the different raw materials used to make a ceramic object can be identified, ranging from clays and other minerals to rock fragments and inorganic or organic temper. The technique moreover feeds into the study of raw material provenance and origin, and is able to discern the different technological procedures followed to make the ceramic object (from shaping to firing), next to providing clues on the function of the object. This information not only helps reconstruct trade and exchange of raw materials and ceramics, but aids in reconstructing society behind the pot.


2020 ◽  
pp. 405-414
Author(s):  
Veronika Valentinovna Tarnopol’skaya ◽  
Tat'yana Vasil'yevna Ryazanova ◽  
Natal'ya Yur'yevna Demidenko ◽  
Oksana Nikolayevna Eryomenko

A technology for pilot production of feed products via microbiological conversion of plant raw materials (mixed substrate of pine sawdust and vegetative part of Jerusalem artichoke) by Plerotus ostreatus PO-4.1 and Pleurotus djamor PD-3.2 strains is developed. The technology includes hydrodynamic activation of substrate at the seed stock production stage. The overall technology includes three key stages: submerged fermentation of pure cultures of production strains; submerged-solid phase fermentation of hydrodynamicly activated plant raw materials for seed stock production; solid-state fermentation of mechanically ground plant substrate for feed products production. A successful approbation of submerged-solid state fermentation of production strains on media containing 3% of hydrodynamicly activated raw materials allowed for obtaining seed stock with 14.5 g/l yield of submerged mycelium biomass fully adopted for this type of substrate. Further use of this seed stock biomass at the solid state fermentation stage makes the overall process duration three times shorter compared to existing technologies for direct wood waste bioconversion. The pilot plant results show valuable practicability of plant raw material hydrodynamic activation with the purpose of enhancing its bioaccessibility with consequent increase in degree of microbiological conversion. The product of bioconversion contains 14–16% of protein, biofiber, vitamins and minerals and could be considered for successful use as feed by agricultural enterprises.


Author(s):  
Anar Kareeva ◽  
Uilesbek Besterekov ◽  
Perizat Abdurazova ◽  
Ulzhalgas Nazarbek ◽  
Irina Pochitalkina ◽  
...  

Abstract The article presents the results of studies of the process of obtaining NPK fertilizer from low-grade phosphate raw materials with P2O5 of about 18%. Phosphate raw materials were leached with a mixture of nitric-phosphoric acids with the addition of potassium carbonate, which serves as a source of potassium in the final product. The main parameters determined were the content of the main nutrients P2O5:N:K2O, temperature and time of the leaching process. According to the graphical method, the “apparent” activation energy of the heterogeneous process is found, which is equal to 3.8 kJ/mol indicates the intradiffusion nature of the process. Methods of chemical analysis, scanning electron microscopy and XRD analysis were used for a comprehensive study of raw materials and final products.


2021 ◽  
Vol 1028 ◽  
pp. 185-190
Author(s):  
Hafizhah Ellora Della ◽  
Mochamad Zainuri ◽  
Pelangi Az Zahra ◽  
Puri Olyvia Swastika ◽  
Triwikantoro

This research study about the influence of carbon concenttration as coating on electrical conductivity of LiFeSi0.03P0.97O4/C. Synthesis of LiFeSi0.03P0.97O4/C was carried out different carbon concentrations of 7, 9, and 11 wt%. The raw materials used are Fe2O3, Li2CO3, (NH4)2HPO4, SiO2 as ion Si doping, and glucose as carbon sources. The XRD analysis results showed that all the diffraction peaks in samples were the olivine LiFePO4 phase. From the EIS result, Samples with the addition carbon concentration of 9 wt% produce the highest electrical conductivity values of 4.18 x 10-7 S/cm.


Author(s):  
Magdalena Śmiglak-Krajewska

The main purpose of this paper was to identify the factors affecting the selection of raw materials used by feed operators in feed production. An attempt was also made to indicate the barriers to increasing the use of native protein plants by feed operators in feed production. Today, many EU countries (including Poland) primarily rely on vegetable protein derived from genetically modified soya bean meal (mainly imported from South America and the U.S.) in addressing their needs for protein raw material used in animal feed. For many years now, Poland has taken steps to increase the production and use of native protein raw material to partially replace soya bean meal imports. The use of mixes of diverse domestic protein sources derived from grain legumes (peas, field beans, lupine) can provide an advantageous alternative to compound feeding stuff based on imported post-extraction soya bean meal. To meet the objective defined above, this paper relied on the results of a 2018 survey conducted with a sample of 29 feed operators located across the country. More than half (55%) of the enterprises surveyed did not use legumes in feed production; the use of legumes was above 10% in only 3% of respondents. When asked about the key factors affecting the selection of raw materials used in production processes, the respondents declared to be interested in buying large batches of homogeneous raw materials that meet specific quality parameters (33% replied “rather yes” and 67% replied “definitely yes”). The protein content of plant seeds used in feed production was identified as another aspect of extreme importance (55% replied “rather yes” and 24% replied “definitely yes”).


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