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Orazimbetova Gulistan Jaksilikovna, candidate of technical sciences, associate professor, doctoral candidate, Research and test center "Strom" Institute of General and inorganic chemistry of the Academy of sciences of the Republic of Uzbekistan, E-mail: guli@inbox.ru Iskandarov Mastura Iskandarovna, doctor of technical sciences, professor, head of the Research and test center "Strom" Institute of General and inorganic chemistry of the Academy of sciences of the Republic of Uzbekistan, E-mail: mastura-iskandarova@rambler.ru Mironyuk Nina Anatolievna, senior research associate Research and test center "Strom" Institute of General and inorganic chemistry of the Academy of sciences of the Republic of Uzbekistan Kurbanova Aypara Djoldasovna, candidate of chemical sciences, senior lecturer at the Tashkent Institute of Engineers and Irrigation and Melioration of Agriculture
INVESTIGATION OF REACTIVITY AND SYNTHESIS OF CLINKERS FROM RAW MATERIALS WITH THE USE OF BASALT ROCKS
Abstract: Raw mixes using basalt rocks have high reactivity, which allows to complete the processes of mineral formation at a temperature of 30-50 °C below with a reduction in heat consumption for clinker burning. When two-component raw mixes were fired using limestone from the Jamansay-2 deposit and basalt rock of the Berkuttau section, the optimum sintering interval of clinker (1400-1420) °C. For raw mixes that include limestone from the Jamansay-2 field, the clay component of the Berkuttau section and iron-containing cinder of the Almalyk Miningand Metallurgical Combine, the optimum firing temperature is 1450 °C, which corresponds to the classic temperature indicator for the production of portland cement clinker.
Keywords: limestone, clay, basalt, aluminosilicate and iron-containing component, roasting, clinker, cement, free calcium oxide.
Introduction: All available information on basalt is related to geological processes of volcanic eruptions. An analysis of literature data on the location of the basalt rock of Uzbekistan's deposits showed that the main occurrence of basalt igneous rock can be observed on the surface of the earth's crust. Such an arrangement of basalts occurred after oceanic volcanic eruptions, with the rapid cooling of magmas, when, along with numerous magmatic rocks, basalt was formed [1-2].
The igneous rocks (basalts, gabbros, diabase-porphy-rite, etc.) differ in their crystalline structure from traditional iron-containing additives (with a melting point of 13801450 °C) and melt at lower temperatures (1105-1250) °C, which leads to a lower the sintering temperature of the raw material mixtures containing these rocks. Melting tempera-
ture range of basaltic rock of the Berkuttau section (11801190) °C. Samples of basalt sand and basalt sample of the Berkuttau section are similar in chemical composition and content of regulated oxides fully comply with the requirements imposed by.
O'zDSt 2950: 2015 for igneous rocks used in the production of portland cement clinker, and are recommended for use when conducting technological tests as aluminosilicate and iron-containing components [3].
The formulation of the problem. Studies have been conducted to establish the possibility of clinker synthesis based on local raw materials using basalt rocks for the production of general construction and sulfate-resistant cements of the brand with a strength of at least 400.
Methods of research materials, equipment and tools:
Chemical analysis of raw materials, raw mixes and roasting products was performed in accordance with the requirements of GOST 5382-91 "Cements and materials of cement production Chemical analysis methods" [4]; The mineralogical composition of the raw materials and calcination products was determined on an x-ray unit "DRON-4" with a copper anode at a shooting speed of 2 degrees per minute and using d-quartz as an external standard; the temperature range of melting of the basaltic rock of the Berkuttau section was established according to the method developed at the Research and test center "Strom" Institute of General and inorganic chemistry of the Academy of sciences of the Republic of Uzbekistan using a high-temperature electric heating furnace; Compositions of raw mixes and clinkers for general construction and sulphate-resistant cements are calculated according to a special program using the formulas S.D Okorokova in accordance with the requirements of O'zDSt2801: 2013 "Portland cement clinker. Technical conditions" [5]; firing of raw mixes was carried out
in a laboratory silica oven; the temperature during firing was controlled by a TPR thermocouple with a secondary device; Grinding experienced clinkers on cement was carried out in a laboratory ball mill MBL when loading "grinding media: grind-able material = 5.5: 1"; assessment of the quality of raw materials for clinker production was carried out in accordance with the requirements of O'zDSt 2950: 2015 "Raw materials for the production of portland cement clinker. Technical conditions".
Results and discussion: On radiographs of a technological sample of basalt from the Berkuttau section (Fig. 1), diffraction reflections of chlorites dominate with d/n = (0.649; 0.466; 0.442; 0.402; 0.384; 0.369; 0.360; 0.352; 0.318; 0.292; 0.272; 0.258 ...) nm. In addition, in the sample there are: quartz with d/n = (0.334; 0.222; 0.212; 0.196; 0.181 ...)nm.; calcite with d/n = (0.303; 0.248; 0.232; 0.206 ...)nm.; dolomite with d/n = (0.285; 0.217; 0.206 ...)nm.
The increased background level of diffraction reflections indicates the presence of a glass phase in the basalt sample of the Berkuttau section, which is typical of igneous rocks.
Figure 1. Radiograph of a technological sample of basalt from the Berkuttau section, nm
Differential-thermal analysis established that the process of basalt heating of the Berkuttau section (Fig. 2) is characterized by twelve endothermic effects at (215; 284; 336; 342; 363; 377; 412; 485; 557; 571; 731; 825) °C and five exothermic effects at (79; 135; 169; 619 and 637 °C. Endothermic effects are associated with the phased decomposition of chlorites (aqueous silicates of Al; Mg; Fe3 + of complex and variable composition), dolomites, and calcium carbonate. Exothermic effects correspond to the processes of rearrangement of the crystalline structure of the igneous rock. The total mass loss in the temperature range (60-900) °C along the thermogravimetry curve is 11.85% [6].
Figure 2. Heating curves of basalt of the Berkuttau section
It has been established by calculation that on the basis of two-component raw mixes using (82.09-84.22)% limestone of the "Jamansay-2" deposit and (15.78-17.91)% of the basalt rock of the "Berkuttau" section as aluminosilicate and iron-containing component it is possible to obtain clinkers for general construction cements with chemical-mineralogical composition and modular characteristics that meet the requirements of O'zDSt 2801.
In order to reduce the mass fraction of basaltic rock of the Berkuttau section (from 15.9 to 8.09)%, the introduction of (from 0.43 to 6.84)% of the clay component of the North Jamansay deposit is recommended in the composition of two-
component raw mixes. Three-component raw mixes and clinker based on limestone from the Jamansay-2 field, the clay component of the North Jamansay field and basalt rock from the Berkuttau section, in terms of chemical-mineralogical composition and modular characteristics, fully comply with the requirements of O'z DSt 2801.
Raw mixture number 2; 3; 6; 12; 15; 16 studied the reactivity by burning in the temperature range (1000-1450) °C
and analysis of the products of burning for residual content of free calcium oxide. The burning of the pellet samples (d = h = =20)mm was performed in a laboratory silica oven with sampling in the temperature range (1000-1450) °C and 1450 °C with an exposure time of 30 minutes. The amount of free calcium oxide in the calcination products was determined by the alcohol-glycerate method according to GOST 5382. The results of the determination saregivenin (Table 1).
Table 1. - The content of free calcium oxide in the burning products
No. Name and the material composition of the raw mix,% Content of free calcium oxit le,%
1000 1100 1200 1300 1400 1450 1450°C, 30 min shutter speed
1. Raw mixture number 2 - Technological test of limestone - 83.19 - Technological sample of basalt - 16.81 SC (saturation coefficient) KH = 0.90; n = 2.72; p = 2.31 30.10 21.15 15.45 5.00 0.95 0.02 -
2. Raw mixture number 3 - Limestone technology test - 83.61 - Basalt technology test - 16.39 SC = 0.92; n = 2.73; p = 2.32 31.80 22.10 19.15 5.80 1.00 0.03 -
3. Raw mix number 6 - Limestone Technology Test - 83.52 - Technological test clay comp.- 2.08 - Basalt technology test - 14.40 SC = 0.90; n = 2.80; p = 2.47 32.85 22.05 15.70 5.95 1.12 0.08 -
4. Raw mixture number 12 - Technological test of limestone - 83.83 - Technological test clay comp.- 9.89 - OgarkiAlmalyk Miningand Metallurgical Combine - 6.28; SC = 0.90; n = 2.17; p = 0.95 30.20 22.00 17.42 6.40 2.65 0.15 -
5. Raw mixture number 15 - Limestone Technology Test - 84.10 - Technological test clay comp.- 9.32 - OgarkiAlmalyk Miningand Metallurgical Combine - 6.58 SC = 0.92; n = 2.12; p = 0.90 33.40 24.10 20.20 7.35 2.90 0.20 -
6. Raw mix № 16 SR PTs (sulphate-resistant portlandcement) - Limestone Technology Test - 82.72 - Technological test clay comp.- 8.90 - Ogarki Almalyk Miningand Metallurgical Combine - 8.38; SC = 0.87; n = 1.94; p = 0.75 27.94 21.10 17.35 6.05 1.78 0.15 -
According to the data set out in the (table 1), it can be concluded that the processes of formation and assimilation of free calcium oxide in raw mixtures based on the tested raw materials proceed intensively.
The maximum amount of free calcium oxide is observed at a temperature of 1000 °C. With increasing temperature, CaOs content.decreases sharply due to the onset of mineral formation processes [7].
Roasting products synthesized at a temperature of 1450 °C from 30 min. extract, do not contain free CaO, which indicates its full absorption in the processes of formation of the clinker phases.
The presence of basaltic rock with a melting point in the range (1180-1190) °C intensifies the process of mineral formation and accelerates the absorption of free calcium oxide, which is almost completed at a temperature of (1420-1450) °C, which is relatively lower than in raw mixtures containing cinders ofAlmalyk Miningand Metallurgical Combine.
Experimental data show that for firing raw mixes the optimum temperature range is (1400-1420) °C. To complete the processes of mineral formation in raw mixtures, the temperature range rises to (1430-1450) °C.
Conclusion: Thus, it was experimentally established that the raw material mixtures based on the tested raw materials have high reactivity. The mineralogical composition of the technological sample of the basalt of the Berkuttau section is characteristic of igneous rocks and is represented by a natural mixture of chlorites, quartz, calcite, dolomite and glass phase.
It was established experimentally that the temperature range of melting of the basalt rock of the Berkuttau section (1180-1190) °C. The chemical composition of the technological sample ofbasaltic rock of the Berkuttau section according to the content of regulated oxides (SiO2 = 53.28; Al2O3 = = 16.30; MgO = 5.32; SO3 = 0.43; R2O = 4.50)% meets the requirements of O'z DSt2950: 2015 to the chemical composition of igneous rocks used in the production of portland cement clinker.
References:
1. Kurbanov A. A. The specific features of the Kyzylkum basalts. Monograph. - Tashkent: Fan. 2009.- 160 with.
2. URL: http://www.inmoment.ru/magic/healing/bazalt.html.
3. O'z DSt 2950: 2015 Raw materials for the production of Portland cement clinker. Technical conditions.
4. GOST 5382-91 Cements and materials for cement production. Chemical analysis methods.
5. O'z DSt 2801: 2013 Portland cement clinker. Technical conditions.
6. Gorshkov V. S., Timashev V. V., Saveliev V. T. Methods for physico-chemical analysis ofbinders.- M.: Higher school, 1981.
7. Butt Yu. M., Timashev V. V. Workshop on chemical technology of binders.- M.: Higher school, 1978.
