The second year

As part of the project, a number of works were completed in 2023. A theoretical scientific and technical review of the production technology and the main technological stages of obtaining geopolymer materials was carried out, during which the main technological stages of the synthesis of geopolymer materials were determined. First of all, a review of the main technological methods for obtaining polymer materials was carried out. It was found that the most appropriate choice of the filling method, coupled with the method of direct foaming of geopolymer materials, as well as the method of exposure to microwave radiation.

Based on the specifics of the selected methods, further technological stages of obtaining geopolymers were determined: selection of raw aluminosilicate materials; preparation of raw materials for further use; preparation of an alkaline activator solution; preparation of foaming agents for further use, mixing of prepared raw materials and an alkaline activator solution, introduction of foaming agents; molding of the resulting geopolymer paste, foaming of geopolymer paste; drying of the material; mechanical processing of dried material.

The sampling of ash and slag waste from the ash dump of the Novocherkassk GRES and the dump rock of coal mines (Krasnosulinsky district, Gukovo, Almazny settlement) was carried out, preparing them for analysis and synthesis. The samples were crushed in special mills or otherwise, the average sample was taken by quartering (when sampling from battery cyclones or scrubbers), the samples were dried at a temperature of 110 ° C. The initial moisture content of ash and slag waste according to the measurement results was 35%. It was found that in order to achieve a moisture content of ash and slag waste of 13%, it is necessary to dry for 6 hours at a temperature of 110 ° C. After drying, the ash and slag waste is subjected to granulometric analysis. It was found that 72% of the particles of the test material have a size of more than 250 microns, and therefore their further grinding is necessary. The grinding of ash and slag waste was carried out in ball drum mills, burnt rock from coal mine dumps – in a disk eraser, for 8 hours, as well as in a planetary mill for 1 hour. At these time values, 80% of the tested samples are crushed to a particle size of less than 250 microns. Further processing of the material in the grinding equipment is impractical, due to increased energy costs.

The search, analysis and selection of the optimal activator and pore-forming agent for the synthesis of foamed geopolymers has been carried out. A mixture of sodium hydroxide and sodium silicate was chosen as the most promising and cheapest activating solution for the production of foamed geoplimers based on ash and slag waste. Phosphoric acid, which has the ability of phosphate activation of aluminosilicates, was chosen as the most promising acid activator for the production of foamed geoplimers based on burnt host rocks of coal mine dumps. Hydrogen peroxide, sodium hypochlorite, sodium perborate, aluminum and silicon were considered as a pore–forming additive for the synthesis of foamed geopolymer materials based on waste from coal-fired power plants. Hydrogen peroxide and aluminum powder were chosen as the most promising and cheapest. The physical method of porosity formation in the production of geopolymers based on coal mining waste – microwave radiation is considered. With microwave radiation, the temperature rises rapidly, which leads to the capture of the formed air bubbles by a geopolymer grid and a porous structure is created.

Studies have been conducted on the selection of the optimal composition for the synthesis of foamed polymers. The optimal raw material composition for the synthesis of geopolymers, wt. %: ash–slag mixture – 76, sodium silicate – 19, sodium hydroxide – 3, aluminum powder – 2, water (over 100) - 6. The optimal composition for the synthesis of foamed geopolymers based on burnt rock of coal mine dumps by weight has been established. %: burnt rock of coal mine dumps – 67.8, an aqueous solution of orthophosphoric acid (14M) – 32.2 with a mass ratio of the activator to the aluminosilicate precursor equal to 0.475.

Methods and approaches for the development of computer-aided design of hierarchical geopolymer materials and modeling of mass transfer in a porous medium of geopolymerization products of energy waste, including impurity elements, are described. The parameters of models of geopolymer structures based on a sodalite framework with a different Si/Al ratio have been developed. To compensate for the excess charge, alkali metal ions and water molecules were introduced, corresponding to normal conditions. The regularities of mass transfer in a porous medium of depolymerization products have been established. The mechanism of immobilization in hierarchical geopolymer materials, which determines the mass transfer of geopolymerization products in a porous medium, is investigated. The possibility of structural rearrangement of water molecules allows them to take positions that increase the stability of the aluminosilicate framework.

The curing process has been studied, since the temperature and curing time directly affect the physico-mechanical properties of the synthesized product, such as ultimate compressive strength, density, porosity, etc. It was found that in the synthesis of porous geopolymers based on ash and slag waste from Novocherkassk GRES, the optimal temperature and time parameters are the curing mode in a drying cabinet at a temperature of 90 ℃ and exposure for 12 hours, and on the basis of coal mining waste when exposed to microwave output power of 1000 W for 10 minutes followed by thermal post-treatment in a drying the cabinet at a temperature of 100 ℃ for 24 hours.

The average density of geopolymer samples was determined according to GOST 17177-94. It was found that samples of geopolymers based on coal combustion waste have a density of 322 ± 6 kg/m3, which allows them to be classified as light thermal insulation materials, samples of geopolymers based on coal mining waste have a density of 943 ± 9 kg/m3, which shows that the materials under development belong to the class of structural and thermal insulation. The average porosity of the developed materials has been determined, according to GOST 12730.4-2020. It was found that the porosity of the synthesized foamed geopolymers is 79.02 ± 0.37% and 64.34 ± 1.54%, for samples based on coal combustion waste and coal mining waste, respectively. It was found that samples of geopolymers based on coal combustion waste mainly consist of pores with a size of 0.2-0.4 mm, samples based on coal mining waste consist of pores with a size of 0.2-0.6 mm, which shows the uniformity of the distribution of the cellular structure in the materials. As a result of determining the average coefficient of thermal conductivity, it was found that for a geopolymer based on coal combustion waste, this value is 0.0833 ± 0.0045 W/(m·K), for a geopolymer based on coal mining waste - 0.107 ± 0.002 W/(m·K), which corresponds to the expected results and allows the developed materials to be classified as thermal insulation, which, according to the definition, have a thermal conductivity of no more than 0.175 W / (m · K). As a result of strength tests, it was found that samples of geopolymers based on coal combustion waste have an average compressive strength of 0.51 ± 0.09 MPa, samples of geopolymers based on coal mining waste – 10.2 ± 0.04 MPa, which, according to definition, corresponds to structural and thermal insulation materials.

The methods and approaches that determine the relationship between the structure of polymer materials and their properties are described. A mathematical model of the relationship between the composition of geopolymer precursors, their synthesis modes and properties of synthesized foamed geopolymer materials has been developed. The model is developed on the basis of quantitative structure-property relations (QSPR). QSPR in the context of materials science makes it possible to predict the physical and physico-chemical properties of materials. This approach allows us to discover hidden patterns and connections between the structure and properties of materials. To implement this approach, the basics of regression analysis methods and the partial least squares method are considered. Analytical dependences defining a model for predicting the properties of synthesized foamed geopolymer materials based on the composition of geopolymer precursors and their synthesis modes are proposed.

During the reporting period, laboratory staff participated in the following conferences and forums:

1. International Scientific and Practical Conference "Materials Science, Shaping technologies and Equipment 2023" (ICMSSTE 2023), Yalta, from 05/16/2023 to 05/19/2023.;
2. International Scientific Conference "Rational use of natural resources and processing of technogenic raw materials: fundamental problems of science, materials science, chemistry and biotechnology", Alushta, from 06/05/2023 to 06/09/2023.;
3. VIII All-Russian competition of scientific research works of students and postgraduates" within the framework of the VIII All-Russian Forum "Science of the Future – Science of the young",
4. International Scientific and Technical Conference "Modern trends and prospects for the development of processing technologies and equipment 2023" (ICMTMTE 2023), Sevastopol, from 04.09.2023 to 08.09.2023.;
5. International Scientific and Technical Conference "Construction, Architecture and Technosphere Safety", Sochi, from 09/10/2023 to 09/16/2023.

Equipment, materials and components for scientific research equipment were purchased in order to implement the project, including:

1. Horizontal Digital Dilatometer Orton Ceramic DIL 1410V;
2. SepaBean Machine 2 Flash Chromatograph;
3. Stereo Microscope SZM-110;
4. Installation of differential thermal (DTA) and thermogravimetric (TGA) analysis;
5. Alpha 202G Manual two-disc grinding and polishing machine;
6. Laser analyzer of microparticles LASKA TD;
7. Спектрометр Syntez Lab PQ Industry Basic;
8. Horizontal oven Walter glass kf-06061;
9. Thermal imager DT-9897H;
10. Laboratory analytical scales BELDA-224 C;
11. Adam HCB-302 laboratory scales;
12. DENSITY KIT for determining the density of solids and liquids.

During the reporting period, the laboratory staff published the following articles in scientific publications indexed in the Web of Science Core Collection database:

1. The article "Mechanism of Cs Immobilization within a Sodalite Framework: The Role of Alkaline Cations and the Si/Al Ratio" by A.S. Kasprzhitsky, Ya.M. Ermolov, V.B. Mishchinenko, A.A. Vasilchenko, E.A. Yatsenko, V.A. Smoliy in the journal "International Journal of Molecular Sciences" Q1, 2023, Vol. 24(23), 17023.
2. The article "Structure of bound water layer on montmorillonite surface: The role of transand cis- vacant sites" by A.S. Kasprzhitsky, A.A. Kruglikov, Ya.M. Ermolov, V.A. Yavna, M.S. Pleshko, G.I. Lazorenko was published in the journal "Applied Surface Science", Q1, 2023, September, Vol. 642, 158565.
3. The article "Study on the Curing and Foaming of Surfactant-Modified Geopolymer Gels Based on Ash and Slag Waste from Coal Combustion" by E.A. Yatsenko, S.V. Trofimov, B.M. Goltsman, Li Wensheng, V.A. Smoliy, A.V. Ryabova, L.V. Klimova, A.I. Izvarin in the journal "Gels", Q1, 2023, December, Vol. 10(1), 19.
4. The article "Recycling of Coal Combustion Waste through Production of Foamed Geopolymers with Improved Strength" by E.A. Yatsenko, B.M. Goltsman, Yu.V. Novikov, S.V. Trofimov, A.V. Ryabova, V.A. Smoliy, L.V. Klimova in the journal "Sustainability" Q2, 2023, Vol. 15(23), 16296.
5. The article "Recycling ash and slag waste from thermal power plants to produce foamed geopolymers" by E.A. Yatsenko, B.M. Goltsman, A.I. Izvarin, V.M. Kurdashov, V.A. Smoliy, A.V. Ryabova, L.V. Klimova was published in the journal "Energies", Q3, 2023, Vol. 16 (22), 7535.
6. The article "Structural and electronic characteristic dataset of the water on the basal surface of the cis- and trans-vacant variety of a montmorillonite" by A.S. Kasprzhitsky, A.A. Kruglikov, Ya.M. Ermolov, G.I. Lazorenko was published in the journal "Data in Brief", Q3, 2023, Vol. 51, 109668.

4 intellectual property objects have been developed:

1. Patent of the Russian Federation for invention No. 2802651 "Raw material mixture based on ash and slag waste for the production of geopolymer material with low density". Copyright holder: Federal State Budgetary Educational Institution of Higher Education "South Russian State Polytechnic University (NPI) named after M.I. Platov". Authors Yatsenko E.A., Goltsman B.M., Izvarin A.I., Smoliy V.A., Klimova L.V., Trofimov S.V. Priority date April 05, 2023 Date of state registration in the State Register of Inventions of the Russian Federation August 30, 2023 The patent has been registered in the USISU of R&D. The exclusive right to an invention expires on April 05, 2043.
2. RF patent for invention No. 2809988 "Method for determining the plasticity of clay raw materials". Copyright holder: Federal State Budgetary Educational Institution of Higher Education "South Russian State Polytechnic University (NPI) named after M.I. Platov". Authors Lazorenko G.I., Kasprzhitsky A.S., Kruglikov A.A., Mishchinenko V.B., Yatsenko L.A., Yatsenko E.A. Izvarin A.I. Priority date May 19, 2023. Date of state registration in the State Register of Inventions of the Russian Federation December 20, 2023. The patent was registered in the USISU R&D. The exclusive right to the invention expires on May 19, 2043.
3. Certificate of state registration of the computer program No. 2023687477 "Mass transfer in hierarchical geopolymer structures" (MIGS)". Copyright holder: Federal State Budgetary Educational Institution of Higher Education "South Russian State Polytechnic University (NPI) named after M.I. Platov". Authors Lazarenko G.I., Kasprzhitsky A.S., Kruglikov A.A., Mishchenko V.B., Yatsenko E.A. Application No. 2023686697. The date of receipt is December 06, 2023. The date of state registration in the Register of computer programs is December 14, 2023. The program is registered in the USISU R&D. The validity period is 120 months.
4. The secret of production (know-how) "Modified component composition of a raw material mixture for obtaining a geopolymer material" by the authors Yatsenko E.A., Goltsman B.M., Smoliy V.A., Ryabova A.V., Klimova L.V., Izvarin A.I., Trofimov S.V., Golovko D.A., Romanyuk V.S., Kurdashov V.M. The order of the YURGPU (NPI) No. 2-46 dated 11/29/2023 "On the introduction of a trade secret regime". Trade secret No. 01 KT-23. The know-how is registered in the USISU of R&D. The validity period is until the cancellation of the protection of the trade secret regime.

A new grant from the Russian Academy of Sciences was received, Agreement No. 23-79-01004 dated 08.08.2023 "Study of the fluxing effect of fluoride-borate mixtures during heat treatment of heat-insulating aluminosilicate compositions", head Goltsman B.M., financing organization of the Platov South Russian State Polytechnic University (NPI), competition 2023 "Conducting initiative research by young scientists" of the Presidential Research Program projects implemented by leading scientists, including young scientists."

In the reporting period, Lyubov Alexandrovna Yatsenko, an employee of the laboratory, was awarded the degree of Candidate of Technical Sciences, the order of the Higher Attestation Commission on the issuance of diplomas of Candidate of Sciences No. 1375/nk dated June 28, 2023, the council on the basis of the St. Petersburg State Technological Institute (Technical University). Dissertation topic "Development of technology of porous silicate materials based on natural amorphous siliceous rocks and complex poroobrazovatel", date of protection 02/15/2023

The internship of graduate students, engineers of the laboratory "Recycling of fuel energy waste" - Novikov Yuri Vladimirovich and Tkachenko Vadim Dmitrievich at the Indian Institute of Technology Indore (Indore, Republic of India) in the laboratory of building materials and solid mechanics, was implemented in the period from November 16 to December 21, 2023 (37 days). The internship was conducted under the guidance of Sandeep Chaudhary, Professor of the Department of Civil Engineering and scientific director of the laboratory "Recycling of Fuel Energy Waste". During the internship, Novikov Yu.V. and Tkachenko V.D. The following works were carried out: the study of scientific publications written by laboratory staff; synthesis of samples of mechanochemically activated geopolymer concretes based on fly ash and granular ground blast furnace slag; studies of the effect of the temperature regime of drying samples of geopolymers on their mechanical properties; studies of the mechanical characteristics of synthesized samples; studies of the phase composition of synthesized samples; microscopy studies of the raw materials used; research on the possibility of using solar energy waste (scrap solar panels) for the synthesis of gas-filled silicate materials; the final collection of theoretical and practical data for writing a scientific publication.

A set of works has been carried out on the formation of a program and methodology for research tests of the developed material, taking into account modern regulatory documents. The purpose of the tests is defined, which is to study the characteristics of the test objects and ways to achieve the set values. The test object has been determined – the granulate of foamed geopolymer material, a list of regulatory and legal reference documents has been compiled, a list of testing tools has been left, developed according to the selected regulatory documents. a test program has been developed that includes the determination of the following parameters of the granulate of foamed geopolymer material and the accuracy of their measurement: fraction; bulk density; humidity; content of split grains; compressive strength in a cylinder; frost resistance to weight loss after 15 cycles of alternating freezing and thawing; weight loss in determining resistance to silicate decomposition; weight loss during boiling; the content of water-soluble sulfurous and sulfuric acid compounds; loss of mass during calcination; coefficient of thermal conductivity; the value of the total specific effective activity of natural radionuclides.

A scientific school was held from May 28 to June 2, 2023 on the basis of the South Russian State Polytechnic University (NPI) named after M.I. Platov, Novocherkassk, Rostov region. Within the framework of the scientific school "Green Future" 59 reports were heard, in sections: "Technological aspects of recycling of industrial and household waste" – 23 reports; "Problems and prospects of synthesis of new materials for the "green future" – 21 reports; "Tasks of modern digital materials science" – 15 reports.

The output of the collection:

Scientific school "Green Future" for young scientists, postgraduates and students. Novocherkassk, 05/28/2023 - 06/02/2023: Abstracts / South Russian State Polytechnic University (NPI) named after M.I. Platov. – Novocherkassk: Publishing house "NOK", 2023. – 240 p. ISBN 978-5-8431-0514-3.

A new additional professional program "Green Technologies of the Future", 16 hours, was developed and implemented. Approved at the meeting of the Academic Council of YURGPU (NPI) No. 6 dated March 1, 2023, the order of YURGTU (NPI) on the implementation and cost of educational services under the additional professional program No. 1-94 dated 03/24/2023. The program was implemented at the Department of General Chemistry and Technology of Silicates. 33 people have been trained.

The following lectures were delivered during the educational program:

1. Waste management in construction (lecturer Chaudhary S.);
2. Computer design of "green" materials (lecturer Kasprzhitsky A.S.);
3. Additional cementing materials (lecturer Chaudhary S.);
4. Multiscale computer modeling of functional geopolymer materials (lecturer Kasprzhitsky A.S.);
5. Geopolymers are carbon-neutral material for green construction (lecturer Yatsenko E.A.);
6. Utilization of fuel energy waste (lecturer Smoliy V.A.);
7. Foam glass is a modern thermal insulation material (lecturer B.M. Goltsman);
8. Environmental aspects of protection of metals from corrosion (lecturer Ryabova A.V.).