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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: [email protected] 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: [email protected] 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
OPTIMIZATION OF RAW MATERIAL MIXTURES FOR BURNING PORTLANDCEMENT CLINKERS at JV LLC "TITANCEMENT"
Abstract: For the purpose of preliminary study of the raw material base of the cement plant of the JV LLC (Joint Venture Limited Liability Company) "Titan cement", the chemical composition of the samples of raw materials selected from various sites of raw materials in the region of the enterprise construction was determined. Technological tests have established that the limestone of the Jamansay-2 deposit, the clayey component of the Severniy Jamansai deposit and the basalt rock of the Berkuttau section of the chemical composition completely meet the requirements of O'zDSt 2950 and are suitable for use as raw materials in the production of portland cement clinkers for cements general construction according to GOST 10178 and sulphate-resistant according to GOST 22266 for compressive strength not less than "400".
Keywords: limestone, clayey component, basalt rock, general construction, sulfate-resistant, technological tests, optimal temperature regime, firing, clinker, milling, cement.
Introduction: After the chemical analysis of technological tests for the production of clinker
the samples, the raw components of the optimal and cement. Technological tests of the limestone
chemical composition are established, which are of the Jamansay-2 deposit, the clay component
recommended for selection for use in carrying out of the Severny Jamansai deposit, the basalt rock
of the Berkuttau site and the gypsum stone of the Severniy Jamansai deposit have been selected for carrying out the technological tests [1]. Taking into account the chemical composition of the selected raw components, mixtures of raw mixtures and clinkers for general construction and sulfate-resistant cements were calculated. The reactivity of raw mixtures is determined and the compositions for laboratory and technological tests are optimized. When using raw mixtures of optimal compositions (two-component: limestone, basaltic rock and three-component: limestone, clayey component, cinder), synthetic batches of clinkers for general and sulfate-resistant cements were synthesized [2]. The chemical-mineralogical composition of the experienced clinkers is determined. The physicomechanical properties of cements based on the experimental clinkers and gypsum stone of the Severny Jamansai deposit have been established. Issued Conclusion on the suitability of the limestone deposit "Jamansay-2", the clay component of the field "Northern Jamansai" and the basalt rock of the site "Berkuttau" for the production of portland cement clinkers for general and sulfate-resistant cements with a compressive strength of at least "400". Gypsum stone of the deposit "Northern Jamansai" is recommended for use in the production of cements as a regulator of the setting time.
Formulation of the problem: The studies were conducted with the aim of establishing the possibility of using local raw materials for the production of general and sulfate-resistant Cement cements at the strength of at least 400 at the Titancement JV.
Methods of materials research, equipment and tools: When carrying out tests to assess the quality of raw components, the chemical analysis of raw materials, raw mixtures and firing products was carried out in accordance with the requirements of GOST 5382-91 "Cements and materials of cement production. Methods of chemical analysis "[3]; the mineralogical composition of the raw materials and firing products was deter-
mined on the X-ray unit "DRON-4" with a copper anode at a shooting speed of 2 degrees per minute and the use of d-quartz as an external standard; the temperature interval of melting of the basalt rock of the Berkuttau site was established according to the procedure developed at the Strom Research Institute of the Institute of General and Inorganic Chemistry of the Academy of Sciences of Uzbekistan using a high-temperature electric heating furnace; Compositions of raw mixtures and clinkers for general construction and sulfate-resistant cements are calculated according to a special program using SD formulas. Okorokova in accordance with the requirements of O'z DSt 2801: 2013 "Portland cement clinker. Specifications" [4]; the fineness of grinding raw mixes and cements was determined in accordance with the requirements of GOST 310.2-76 "Cement. Test methods "; physical and mechanical tests of experimental cements are made in accordance with GOST 310.1-310.4 "Cement. Test methods " [5]; 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" [6]; The quality assessment of the gypsum stone used for grinding experienced clinkers on cements was made in accordance with the requirements of O'zDSt 76096 "Gypsum and gypsum anhydrite stone for the production of binding materials. Technical conditions" [7]; Physical and mechanical properties and chemical composition of test cements were classified according to compliance with the requirements of GOST 10178-85 "Portland cement and slag portland cement. Technical conditions" [8]; GOST 30515-97 "Cements. General technical conditions "and GOST 22266-94 "Sulfate-resistant cements. Technical conditions" [9].
Results and its discussion: Raw materials of optimal mixes No. 2 and No. 16, technological characteristics of which are given in (table 1).
Table 1.- Technological characteristics of the experimental raw materials
No. Name and the material composition of the raw mix,% The fineness of grinding on the residue on sieve number 008,% Bulk mass, t/ m3 Angle of natural slope, degree Calculated meanings
Н n P
1 Raw mixture number № 2 - limestone - 83.19 - basalt. breed - 16.81 9.85 0.980 46 ± 2 0.90 2.72 2.31
2 Raw mixture number № 16 - limestone - 82.72 - clay comp.- 8.90 - cinders ofAlmalyk Miningand Metallurgical Combine - 8.38 9.40 0.975 46 ± 2 0.87 1.94 0.75
After dosing and homogenization of the components, the raw materials mixtures No. 2 and No. 16 were moistened to (8-10)% and granulated.
Samples-granules after drying at (100-105) °C were fired in a silicon silicate furnace at optimum temperature conditions with a 30 minute exposure:
- an interval for roasting of raw mix No. 2 (1400-1420)°C
- an interval for roasting of raw mix No. 16 (1430-1450)°C
The firing temperature was measured with a TPD thermocouple with the temperature recorded on the secondary device. After firing, the granules were removed from the furnace for rapid air cooling.
The quality of firing products (experimental clinker No. 2 and No. 16) was controlled by the content of free calcium oxide, which was determined by the alcohol-glycerate method according to GOST 5382.
In the averaged samples of experimental clinkers, it was experimentally established: the content of free calcium oxide:
- in clinker No. 2-0.05%; - in clinker number 16-0.10%
content of chlorine ion, determined according to GOST 5382:
- in clinker No. 2-0.05%; - in clinker number 16-0.06%
The averaged samples of clinker No. 2 and No. 16 were studied by X-ray phase and chemical analysis methods. On the roentgenogram of the experienced clinker No. 2 on the general construction cement (Fig. 1), diffraction reflections characteristic of the main clinker phases are noted: C3S with d/n = (0.298; 0.292; 0.278; 0.272; 0.261; 0.255; 0.214; 0.195; 0.191; 0.181; 0.175; 0.161; 0.156; 0.147 ... )nm; C2S with d/n = (0.288; 0.272; 0.261; 0.230; 0.214; 0.205 ...)nm; C3A with d/n = = (0.272; 0.214; 0.191 ... 0.153)nm; C4AF with d/n = (0,261; 0,191; 0,188 ... )nm. X-ray diffraction clinker No. 16 on sulphate-resistant cement (Fig. 1) shows diffraction reflections of clinker phases characteristic of normalized min-eralogical clinker composition: C3S with d/n = = (0.298; 0.272; 0.261; 0.255; 0.241; 0.214; 0.195; 0.195; 0.181; 0.175; 0.161; 0.156; 0.147 ...)nm; C2S with d/n = (0.288; 0.272; 0, 0.261; 0.228; 0.214; 0.203 ...)nm; C3A with d/n = (0.272; 0.214; 0.191 ... 0.156)nm; C4AF with d/n = (0.277; 0.267; 0.261; 0.203; 0.191 .)nm. The intensity at the background level of diffraction reflections with d/n = =(0.240 and 0.169) nm confirms the data of chemical analysis about low the content of free calcium oxide (0.05-0.10)% in the experimental clinkers No. 2 and No. 16.
Figure 1. X-ray of experienced clinkers, nm: 1 - experienced clinker number 2;
2 - experienced clinker number 16
The presence of clearly fixed diffraction reflections of the main clinker phases and the absence of intermediate phases on radiographs of the clinkers indicates the complete completion of the
processes of mineral formation during the firing of raw mixes.
The chemical and calculated mineralogical compositions of the experimental clinkers No. 2 and No. 16 are listed in (Table 2). Table 2.- Chemical, computational mineralogical composition and modular characteristics of experimental clinkers
№ Name clinker oxide content,%
calcination limit SiO2 ALO, 2 3 Fe O 23 CaO MgO SO3 R2O Modular characteristics of experienced clinkers
H n p
1. Experienced clinker № 2 0.15 22.15 5.80 2.40 65.95 1.05 0.35 1.95 0.20 0.90 2.70 2.42
2. Experienced clinker № 16 0.10 21.92 4.85 6.27 63.40 0.80 0.55 1.85 0.26 0.87 1.96 0.77
Settlement-mineralogical composition,%: experienced clinker No. 2: C3S = 58.92; C2S = 19.05; C3A = 11.30; C4AF = 7.30 experienced clinker No. 16: C3S = 49.96; C2S = 25.14; C3A = 2.19; C4AF = = 19.06 is the content of chlorine ion,% by mass: in clinker No. 2-0.05; in clinker No. 16-0.06 - the content of free calcium oxide,% by weight: in clinker No. 2-0.05; clinker number 16-0.10.
From the data table. 2 it follows that the actual chemical and mineralogical compositions of the experimental clinkers No. 2 and No. 16 are close to the calculated values and meet the requirements imposed by O'zDSt 2801 on the chemical-mineral-ogical composition and modular characteristics of the clinkers for general construction and sulphate-resistant cements.
Conclusion: Thus, it has been experimentally established that based on local raw materials (limestone from the Jamansay-2 deposit, clay
component from the North Jamansai deposit) and basalt rock of the Berkuttau section, it is possible to produce general construction and sulphate-resistant cements, according to the quality indicator that fully complies with the requirements of GOST 10178 and GOST 22266 and of a brand with a strength of at least "400". Raw mixtures are highly reactive. Under optimal firing conditions with the use of the tested raw materials, clinker was synthesized for general construction and sulphate-resistant cements. Experienced clinker in chemi-cal-mineralogical composition and modular characteristics comply with the requirements imposed by O'zDSt 2801 for clinkers for general construction and sulphate-resistant cements. According to the physicomechanical property, cements based on experienced clinkers fully comply with the requirements of GOST 10178 and GOST 22266 and have a strength of at least "400".
References:
1. Butt Yu. M., Timashev V. V. Workshop on chemical technology of binders.- M.: Higher school, 1978.
2. Gorshkov V. S., Timashev V. V., Saveliev V. T. Methods for physico-chemical analysis of binders.- M.: Higher school, 1981.
3. GOST 5382-91. Cements and materials for cement production. Chemicalanalysismethods.
4. O'z DSt 2801: 2013. Portland cement clinker. Technical conditions.
5. GOST 310.1-310.4-81. Cements. Test methods.
6. O'z DSt 2950: 2015. Raw materials for the production of Portland cement clinker. Technical conditions.
7. O'zDSt 760-96. Stone gypsum and gypsum anhydrite for the production of binders.
8. GOST 10178-85. Portland cement and slag Portland cement. Technicalconditions.
9. GOST 22266-94. Sulfate-resistant cements. Technical conditions.
