scholarly journals The chemical reagents influence on the regulation of the powder composite materials setting time for construction purposes

2021 ◽  
Vol 264 ◽  
pp. 02006
Author(s):  
Zokirkhan Munavvarkhanov ◽  
Rustam Soliyev ◽  
Murotbek Boydadayev

Additives were selected, and a method for modifying the structure of gypsum-containing materials for construction purposes and a method for their dispersion were developed. Based on the selected modifiers, effective compositions of composite gypsum-containing materials based on local and secondary raw materials were developed. An increase in their strength and resistance to water was established. The use of gypsum plaster mixes shows their high efficiency and advantages compared to traditional finishing works methods. They provide a high and stable level of finishing quality, reduced transportation costs, and easy recycling of materials. However, despite the high consumer properties, the modern use of compositions based on the most affordable gypsum raw materials in the Republic and the production of gypsum binder beta calcium sulfate semi hydrate is limited to plasters and putties for rooms with normal operation. This is mainly because the compositions have a short setting time, low water resistance, and low strength characteristics. As a rule, the softening factor for such compositions does not exceed 0.5, and the compressive strength is 4-6 MPa

Author(s):  
Grigory Yakovlev ◽  
Jadvyga Keriene ◽  
Valery Grakhov ◽  
Rostislav Drochytka ◽  
Anastasiya Gordina ◽  
...  

The research studies the properties of a high-strength anhydrite composition based on fluoroanhydrite, a waste product of hydrofluoric acid. To activate fluoranhydrite, Na3PO4 sodium phosphate was added to the composition in an amount of 3% of the mass. The physico-chemical studies of the structure and properties of activated fluoroanhydrite conducted using infrared spectroscopy and X-ray phase analysis showed changes in the composition of the hardened composite, and the study of the fluoroanhydrite microstructure revealed the formation of a denser matrix with the increased strength. An increase in the water resistance of the developed binder matrix was noted. The composition can be used as a cheap substitute for gypsum plaster due to the low prime cost of raw materials, and also contribute to the improvement of the environmental situation in fluoroanhydrite disposal sites.


2021 ◽  
Vol 899 ◽  
pp. 675-680
Author(s):  
Soyibon S. Negmatov ◽  
Zokirkhon T. Munavvarkhanov ◽  
Murotbek B. Boydadaev ◽  
Alloberdi M. Madraximov

Additives were selected and a method for modifying the structure of gypsum-containing materials for construction purposes and a method for their dispersion were developed. Based on the selected modifiers, effective compositions of composite gypsum-containing materials based on local and secondary raw materials were developed, and an increase in their strength and resistance to water was established.


2022 ◽  
Vol 4 (6) ◽  
pp. 69-81
Author(s):  
Aleksandr Bahtin ◽  
Nikolay Lyubomirskiy ◽  
S. Fedorkin ◽  
Tamara Bahtina ◽  
G. Bilenko

the use of secondary raw materials for the production of building materials is a modern trend in solving environmental problems. In the Republic of Crimea, dumps of secondary raw materials – phosphogypsum and lime dust – have accumulated in large quantities at various enterprises. The analysis of phosphogypsum, which has been in the dumps for more than 5 years, showed that by its quality indicators it can be attributed to the 2nd grade in accordance with GOST 4013-2019, and the specific effective activity of the material (Aeff) corresponds to the I class of materials, which makes it suitable for the production of gypsum binders. Prototypes-cylinders were made from a mixture of phosphogypsum with lime dust of 1:1 composition at a pressure of 30 MPa and then subjected to hardening according to three schemes, in order to separate the passage of various types of hardening and study each of them for the physico-mechanical properties of the resulting material. The analysis of experimental data made it possible to establish the effectiveness of simultaneous flow in the system of two types of hardening – carbonate and hydration for lime and phosphogypsum components of the raw mixture, respectively. As a result of the organization of a mixed type of hardening of gypsum-lime binder, samples with a compressive strength of 26.5 MPa and a softening coefficient of 0.63 were obtained within 90 minutes. The calcium carbonate formed in the process, which is the product of the reaction between calcium hydroxide and carbon dioxide, significantly increases the water resistance of the hydration products of gypsum binder. It is established that with an optimal combination of technological factors and hardening conditions, a significant increase in the physical and mechanical characteristics of the carbonized material is possible in a short time.


2012 ◽  
pp. 53-58
Author(s):  
S. Afontsev ◽  
N. Zubarevich

The questions of spatial development as a modernization driver (the Kazakhstan case) are considered in this article. The analysis of the regional economic differences makes possible to work out the development guidelines, based on the advantages combination of the basic goods specialization and the policy of transferring growth impulses from the raw materials sector to the industry and service ones. Current challenges and opportunities, which face the Kazakhstan economy, the questions of economic diversification drive up the importance of the connection between spatial development and the cluster priorities. The analytical scheme of macro-regions and diversification through the dynamic focal networks can settle up these challenges.


2020 ◽  
Vol 8 (3) ◽  
pp. 74-78
Author(s):  
Farrux Zulfiyev ◽  

This article is based on the principles of shared financing of the production of raw materials. The article is aimed at financing the production of capital on the basis of equity in order to further strengthen the stability of economic reforms in the republic. At the same time, the essence of equity financing, the risks associated with it, and the efficiency of raw materials are covered


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 788
Author(s):  
Jinlin Mei ◽  
Aijun Duan ◽  
Xilong Wang

The traditional hydrothermal method to prepare zeolite will inevitably use a large amount of water as a solvent, which will lead to higher autogenous pressure, low efficiency, and wastewater pollution. The solvent-free method can be used to synthesize various types of zeolites by mechanical mixing, grinding, and heating of solid raw materials, which exhibits the apparent advantages of high yield, low pollution, and high efficiency. This review mainly introduces the development process of solvent-free synthesis, preparation of hierarchical zeolite, morphology control, synthesis mechanism and applications of solvent-free methods. It can be believed that solvent-free methods will become a research focus and have enormous industrial application potential.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hakim Rabia ◽  
Malek Ould Hamou ◽  
Katarzyna Kasperkiewicz ◽  
Jolanta Brożek ◽  
Maria Augustyniak

Abstract Chemical reagents used in traditional mineral processing can be toxic and hazardous for the environment. Therefore, the use of biotechnological methods is becoming increasingly important. Great hopes are being placed in the use of microorganisms for bio-beneficiation of raw materials. However, assessment of adhesion abilities of bacteria onto minerals surface as well as biosorption of metals are essential steps before designing final process of each ore beneficiation. The main aim of this work was an investigation of biosorption of Cd and Mg, as well as adhesion abilities of five microorganism species with minerals included in the natural mixture of phosphate ore form Djebel Onk, Algeria. The ore, due to its unique composition, created conditions for adhesion of all five tested microbial strains onto apatite surface during incubation at pH 3. Moreover, Rhodococcus erythropolis CD 130, Pseudomonas fluorescens and Escherichia coli adhered distinctly onto apatite surface during incubation at pH 7. Incubation lasting 20 min at pH 4-6 created the most favorable conditions for biosorption of metals by B. subtilis and adhesion of cells. In case of C. albicans, biosorption of metals as well as adhesion of cells onto the mineral surface were more effective after longer time and in a wider pH range.


2012 ◽  
Vol 22 (11) ◽  
pp. 4837 ◽  
Author(s):  
Robin D. Fisher ◽  
John V. Hanna ◽  
Gregory J. Rees ◽  
Richard I. Walton

Author(s):  
Firuza Alisherovna Umarova ◽  
◽  
Kamal Saidakbarovich Rizaev ◽  
Nemat Kayumovich Olimov ◽  
Zaynab Enverovna Sidametova ◽  
...  

Analysis of the assortment of sedatives registered in the Republic of Uzbekistan showed that sedatives are represented on the pharmaceutical market of the country by such dosage forms as drops, solutions, tinctures, syrups, medicinal herbal raw materials, capsules and tablets. Considering that sedatives registered in the form of a substance, with the exception of the dry extract of Leoglycyrfl produced by “Uzkimyofarm”, there are practically no names of S.K. Islambekov in the Joint Stock Company. In this regard, we consider it expedient to create a new sedative medicinal product of herbal origin in the form of a substance and obtain dosage forms based on it.


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