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3PROSPECTS FOR THE USE OF SOLAR ENERGY FOR THE PRODUCTION OF BUILDING MATERIALS FROM LIMESTONE-SHELL WASTE
Bukaev E.Z.
Bukaev Eldar Zakharovich - teacher, DEPARTMENT OF "NATURAL SCIENCES", CASPIAN STATE UNIVERSITY OF TECHNOLOGY AND ENGINEERING NAMED AFTER SH. ESENOVA,
AKTAU, REPUBLIC OF KAZAKHSTAN
Abstract: this article analyzes the use of solar energy in the production of building materials from waste limestone-shell. The analysis of the study shows that the Mangystau region has a huge potential for solar energy to be used in energy-intensive technologies, in particular in the utilization of limestone-shell waste in the production of block stone, which initiates the potential for serious work on the development of solar technology. The proposed technology will contribute to the reduction of accumulated waste and improve the environmental situation in the region.
Keywords: limestone-shell, building material, solar energy, heliocover, heliothermal treatment.
UDC 551
The ecological situation is significantly improved with the use of widespread local stone rocks - limestoneshell waste as aggregates in concrete. Deposits of limestone-shell rock in the form of powerful layers of different lengths are available in Ukraine, Moldova, Azerbaijan, Turkmenistan and in Kazakhstan. At the same time, it should be noted that most deposits are characterized by low strength of limestone-shell rock. In addition, deposits of low-strength limestones are characterized by high fracturing. As a result, waste is formed in the form of sawdust, small pieces and rubble reaching 50% or more of the volume of processed rock mass [1]. These limestone wastes are not used and go into dumps from surfaces that emit dust into the environment, polluting the atmosphere of settlements.
The analysis of literature sources shows [2] that the use of these wastes will not only provide many areas without gravel, crushed stone and sand with local aggregate, but will also reduce the cost of construction, which will mainly contribute to reducing the amount of accumulated waste and improving the environmental situation in the regions.
Under certain conditions and normal cement consumption, structural concretes with a strength of up to 200 kg/cm2 and higher were obtained on a low-strength aggregate, up to 25 kg/cm2 [3].
It has been established that aggregates from low-strength limestone rocks can be used in fine-grained concrete, contrary to the previous opinion about their unsuitability. But not all types of waste can be used as aggregates for concrete, since the technology for producing fine-grained concrete requires crushing and sieving of butte and pieces, which causes additional energy consumption.
The production of concrete as the main building material is associated with the expenditure of a significant amount of fuel and energy resources in the form of low potential heat.
For heating and thermos holding of concrete together with molds, 209-230 thousand kJ is required by calculation, and taking into account heat losses to the environment, the standard consumption for heat treatment of products in pit chambers made of heavy concrete is 691-733 thousand kJ/m2.
The analysis of radiation resources of Kazakhstan shows that the Mangystau region is of particular interest for the use of solar energy. The Mangystau region differs from other regions of Kazakhstan in sharply continental, arid, sultry, long summer, low relative humidity, low clouds. The continentality of the climate, which causes, as a rule, a slight covering of the sky with clouds, causes a large influx of solar radiation. The duration of sunshine in the area under consideration is 2500-3000 hours per year. The analysis of the above data allows us to conclude that the Mangystau region has a huge potential of solar energy for its use not only in science-intensive and energy-intensive technologies of the national economy and in everyday life, but also for its use in energy-intensive technologies, in particular in the disposal of limestone-shell mining waste, which initiates the potentiality of serious work on the development of solar technology.
References
1. Bukaev E.Z., Serikbaeva A.K. Prospects of sulfur applications, oil industry for the production of building materials// Materials of the International scientific and practical Conference "Development of science and technology in the development of the subsoil of Kazakhstan", dedicated to the 90th anniversary of Academician Sh.Yesenova. - Aktau, 2017. - pp.274-278.
2. Duran-Herrera A., De-Leon-Esquivel J., Bentz D.P., Valdez-Tamez P. Self-compacting concretes using fly ash and fine limestone powder: Shrinkage and surface electrical resistivity of equivalent mortars // Construction and Building Materials, - 2019.- Vol.199, - p. 50-62.
3. Grozav V.I., Mutalibova G.K. Influence of water absorption of porous limestone rubble on water absorption and waterproofness of limestone concrete // Nature management and ecological problems of water management and melioration: mater. sci.-tech. conf. - M.: MGUP, 1999. - 100-101 p.
