Ключевые слова: X-ray phase analysis

Investigation properties of waste from the chemical and metallurgical industries to assess the possibility of their use in concrete production

https://doi.org/10.58224/2618-7183-2025-8-4-7
Аннотация
The investigation was conducted on waste from the chemical industry in the form of carbide silt and metallurgical industry in the form of microsilica. For the study, X-ray phase analysis used on a Shimadzu XRD-7000 diffractometer in Cu Kα radiation. Electron microscopic studies were carried out according to GOST R ISO 22309-2015 on a Tescan Vega III SBH electron microscope with an integrated Oxford X-Act energy-dispersive microanalysis system. The Co standard (MAC, reg. no. 9941 Co) and a cassette of standard samples (MAC, reg. no. 11192) were used as samples. Samples were prepared at the Quorum Q150RES spraying station. The amount of raw sludge components was calculated taking into account the preservation of the saturation coefficient and modular characteristics of the cement plant. The calculation of the raw mix consisted in determining the ratios between its components based on the chemical composition of the raw materials and the specified characteristics of the clinker. The possibility is shown and the limits of carbide silt input are determined for use as a lime component of raw sludge in obtaining cement clinker. The possibility of adjusting the lime component of raw sludge by using microsilica is established, which will allow maintaining a balance in silicon content. The identity in the formation of the main clinker phases formed during sludge firing for the pilot sample and the sample made from the enterprise sludge is proven by the X-ray method. Cement of the CEM-II/A22.5N brand was obtained in laboratory conditions, the properties of which correspond to the properties of cement of the industrial enterprise. It is shown that the use of carbide silt and microsilica in the cement industry will allow not only to use them as raw materials, but also to improve the environmental situation in the territory adjacent to these enterprises.
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Investigation of structure and properties of expanded clay waste with the purpose of their use in the construction industry

https://doi.org/10.58224/2618-7183-2025-8-1-4
Аннотация
This paper describes the structure and properties of large-tonnage expanded clay gravel waste, which is generated as dust from the cyclone, or clay dust (when drying granules), and expanded clay dust from filters (when leaving the kiln, from the cooler and screen). The mineralogical and phase composition of expanded clay dust and its hydraulic activity were determined. Clay dust from cyclones corresponds to the specific surface of 2500 cm2/g, and expanded clay dust from filters - 6800 cm2/g, which allows us to recommend it for use as a fine mineral additive to cement mortars and concretes. Due to the fact that the bulk density of clay dust is about 1000 kg/m3, and expanded clay dust - 6300 kg/m3, it allows to recommend it in the form of facilitating raw material additives in the production of wall and partition products. The results of X-ray phase analysis of clay dust from cyclones showed the presence of significant residues of unburnt clay (more than 80%), and the analysis of expanded clay dust from filters showed the presence of solid high-temperature phases consisting of: Quartz (SiO2) – 50.28%, Albite C-1 (NaAlSi3O8) – 14.82%, Microcline maximum (KAlSi3O8) – 15.73%, Lime (CaO) – 2.77%, Calcite (CaCO3) – 5.11%, Alunogen (Al2(SO4)2(H2O)22) – 11.29%. Hydraulic activity of clay and expanded clay dust according to the methods of GOST R 56593 and GOST 30744 showed that it is extremely low, especially for clay dust (0.3 MPa). On the contrary, the characteristics of samples of clay-alkali compositions showed sufficient strength (for clay dust up to 6.8 MPa, and expanded clay dust up to 3.6 MPa), which allows them to be recommended as a component of slag-alkali binder for cement-soil bases of highways.
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