scholarly journals Peculiarities of Portland Cement Clinker Synthesis in the Presence of a Significant Amount of SO3 in a Raw Mix

2021 ◽  
Author(s):  
Oleg Sheshukov ◽  
Michael Mikheenkov
Keyword(s):  
Portland Cement ◽  
Solid Phase ◽  
Experimental Studies ◽  
Total Content ◽  
Raw Material ◽  
Cement Clinker ◽  
Material Base ◽  
Free Lime ◽  
Portland Cement Clinker ◽  
Negative Effect

Due to the depletion of the raw material base and a technogenic materials addition into a raw mix for the Portland cement clinker synthesis, sulfur and its oxides amount in a raw mix increases. According to literature the Portland cement clinker synthesis in the presence of a sulfur oxides significant amount is difficult. As the content of SO3 in the raw mix increases the amount of C2S increases while C3S and C3A amount decrease. With an equal total content of C2S and C3S in the clinker their ratio C3S/C2S decreases with an increased content of SO3. These factors lead to a deterioration in the Portland cement clinker quality. The clinker formation reactions thermodynamic analysis and some experimental studies allow determining reasons for the Portland cement clinker quality deterioration. It was found that the presence significant amount of a SO3 in the raw mix the synthesis in solid phase of low-basic C4A3 S¯ (ye’elimite) is the thermodynamically preferred rather than high-basic C3A and C4AF. As a result, excess and crystallized free lime inhibits the C3S synthesis through the liquid phase. The experimental studies result helped to develop a methodology for calculating the composition of a raw mix from materials with significant amount of SO3. It allows to reduce the SO3 negative effect on the Portland cement clinker synthesis and to obtain high-quality Portland cement.

scholarly journals Effects of Calcination Conditions on the Formation and Hydration Performance of High-Alite White Portland Cement Clinker

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 494 ◽  
Author(s):  
Lei Huang ◽  
Geling Cheng ◽  
Shaowen Huang
Keyword(s):  
Portland Cement ◽  
Mineral Composition ◽  
Sintering Temperature ◽  
Cement Clinker ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Free Lime ◽  
Sintering Time ◽  
Portland Cement Clinker ◽  
White Portland Cement

The purpose of this study was to evaluate the effects of sintering temperature and sintering time on mineral composition of high-alite white Portland cement clinker and hydration activity of the clinker. Effects of sintering temperature and sintering time on clinker mineral composition, C3S polymorph and size and hydration heat release rate were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM), differential scanning calorimetry&Thermogravimetric Analysis (DSC-TG) and isothermal heat-conduction calorimetry. Results shown that, with the increase of sintering temperature (1450–1525 °C) and sintering time (60–240 min), free lime (f-CaO) in clinker decreased, C3S grain size increased, and C3S crystal type changed from T3 to M type and R type, which exhibits higher symmetry. The hydration activity of different C3S crystals ranged from high to low as follows: T3→M1→M3→R@.

Effects of CaF2 on the Formation Kinetics of Portland Cement Clinker

2011 ◽  
Vol 306-307 ◽  
pp. 966-969
Author(s):  
Chun Fang Wang ◽  
Zong Hui Zhou ◽  
Cai Xia Liu ◽  
Xin Cheng
Keyword(s):  
Portland Cement ◽  
Formation Rate ◽  
Reaction Rate Constant ◽  
Cement Clinker ◽  
X Ray Diffraction ◽  
Free Lime ◽  
X Ray ◽  
Formation Kinetics ◽  
Portland Cement Clinker ◽  
Kinetics Of

Through testing the amount of the free lime and the Loss ignition, the clinker formation rate, the reaction-rate constant (K) and the activation energy (Ea) were calculated according to the Gentling equation and Arrhenius equation. The effects of CaF2on the formation kinetics of Portland cement clinker were investigated by analyzing theKandEa. X-ray diffraction (XRD) and scanning electron Microscope (SEM) were used to characterize the phase composition and the morphology of the resulting samples. The results show that the silicate minerals formation is promoted when a proper amount of CaF2is doped into the raw meal. TheKincreased from 0.7450 ×10-5s-1to 7.1588 ×10-5s-1and theEadecreased from 386 kJ/mol to 122 kJ/mol when the amount of CaF2increased from 0.0% to 2.0% in mass. However, the results were reversed at the amount of CaF2exceeding 2%.

scholarly journals Utilization of Iron Ore Tailings as Raw Material for Portland Cement Clinker Production

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Li Luo ◽  
Yimin Zhang ◽  
Shenxu Bao ◽  
Tiejun Chen
Keyword(s):  
Portland Cement ◽  
Iron Ore ◽  
Mechanical Performance ◽  
Mineralogical Composition ◽  
Cement Industry ◽  
Raw Material ◽  
Cement Clinker ◽  
Iron Ore Tailings ◽  
Portland Cement Clinker ◽  
Clinker Production

The cement industry has for some time been seeking alternative raw material for the Portland cement clinker production. The aim of this research was to investigate the possibility of utilizing iron ore tailings (IOT) to replace clay as alumina-silicate raw material for the production of Portland cement clinker. For this purpose, two kinds of clinkers were prepared: one was prepared by IOT; the other was prepared by clay as a reference. The reactivity and burnability of raw meal, mineralogical composition and physical properties of clinker, and hydration characteristic of cement were studied by burnability analysis, differential thermal analysis, X-ray diffraction, and hydration analysis. The results showed that the raw meal containing IOT had higher reactivity and burnability than the raw meal containing clay, and the use of IOT did not affect the formation of characteristic mineralogical phases of Portland cement clinker. Furthermore, the physical and mechanical performance of two cement clinkers were similar. In addition, the use of IOT was found to improve the grindability of clinker and lower the hydration heat of Portland cement. These findings suggest that IOT can replace the clay as alumina-silicate raw material for the preparation of Portland cement clinker.

Co-processing of Grinding Sludge as Alternative Raw Material in Portland Cement Clinker Production

2010 ◽  
Vol 10 (15) ◽  
pp. 1525-1535 ◽  
Author(s):  
T. Punmathari ◽  
M. Rachakornk ◽  
A. Imyim ◽  
M. Wecharatan
Keyword(s):  
Portland Cement ◽  
Raw Material ◽  
Cement Clinker ◽  
Portland Cement Clinker ◽  
Clinker Production

Life Cycle Assessment of Cement Clinker Production Using Coal Gangue as Alternative Raw Material and Fuel

2015 ◽  
Vol 814 ◽  
pp. 435-440 ◽  
Author(s):  
Jia Ping Cui ◽  
Yu Liu ◽  
Zhi Hong Wang ◽  
Xian Zheng Gong ◽  
Feng Gao ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Portland Cement ◽  
Coal Gangue ◽  
Raw Material ◽  
Cement Clinker ◽  
Optimal Dosage ◽  
Portland Cement Clinker ◽  
Almost All ◽  
Clinker Production

Life cycle assessment (LCA) was carried out to quantify and analyze the environmental impact and benefit caused by the utilization of coal gangue as alternative raw material and fuel in cement clinker production. The optimal dosage of coal gangue was determined by comparing among different mixing amount scenarios and Portland cement clinker (clinker without adding any waste) considering the phases of coal gangue disposal, transportation, and raw meal grinding and clinker calcination. The results showed that: 1) After adding coal gangue to the raw meal, almost all the considered environmental impacts of cement clinker including human toxicity potential, photochemical smog potential, especially abiotic depletion potential decreased significantly. However, global warming potential and acidification potential increased slightly in comparison with Portland cement clinker. 2) Compared with the Portland cement clinker, the single environmental indicator reduced after adding coal gangue and the indicator decreased gradually with the dosage increasing.

MANUFACTURE OF MODIFIED ARBOLIT FROM LOCAL RAW MATERIALS: OPTIMIZATION OF COMPOSITION AND PROPERTIES OF RAW MATERIAL COMPONENTS

2019 ◽  
Vol 16 (3) ◽  
pp. 352-365
Author(s):  
A. K. Matyeva
Keyword(s):  
Phosphoric Acid ◽  
Portland Cement ◽  
Raw Materials ◽  
Porous Polymer ◽  
Raw Material ◽  
Cement Clinker ◽  
Liquid Sodium ◽  
Kyrgyz Republic ◽  
Portland Cement Clinker ◽  
Clay Component

Introduction. The creation of energy-saving materials involves the use of local raw materials for products with improved physic-mechanical properties. The author carries optimization of the rational composition and properties of modified arbolite from plant-gypsum composition (PGC). In addition, the author uses modifiers on new ways of preparing the aggregate according to the method of experimental and statistical modeling.Materials and methods. The author used the cereal straw grown in the Kyrgyz Republic (CS), G-5 and G-7 construction gypsum based on local raw materials, ash from the Bishkek Heat and Power Plant (BHPP), portland cement clinker PCC, natural clay (ganch). Moreover, the clay component of the Toloykonsky deposit was used as the clay component. The author also added the liquid glass, latex SCS, the low-concentration resin LCR-3066 + catalyst of ionic type (CIT) as modifiers for the formation of the porous polymer-silicate systems. The paper marked the plasticizing additives in the manufacture of arbolite as SCS, LCR and CIT components. As a retarder the setting of gypsum was added a partial salt 1-hydroxyethylidene-1, 1-diphosphonic acid with triethanolamine and flame retardants. The tests were carried out according to standard methods. To optimize the composition and properties of the polymersilicate-gypsum composition (PSGC), the author carried out a three-factor experiment according to the B3 plan, where three prescription factors varied: X1 – straw content,%; X2 – content of polymer silicate additives (PSA) + plasticizer,%; X3 – gypsum content + portland cement clinker as a nitroperimethyl phosphoric acid (NPA) and flame gypsum retarder.Results. The research showed that at 28 days of age for cement-free gypsum compositions as the content of straw increased, the strength was almost unchanged. When comparing the strength of the same samples of 2 and 28 days strength with the maximum filling of gypsum, the author defined that the PSA content should not exceed 12% when the straw additive was 26% and further PSA increasing did not increase the strength.Discussion and conclusions. As a result, the author achieves maximum strength of the arbolit, when the content of G-7 gypsum is 28-32%, ash is 18-22% and PSC is 8-10%. The maximum value of strength and water resistance of the material is achieved with a rational ratio of components: straw – 24–28%, G-7 gypsum – 30–32% + NSPL – 0,05%; ash – 18–22%; resin – 3066-8-12% + catalyst – 0,3% (87% sulfuric acid, 13% phosphoric acid); PCC – 3–5%; clay-gypsum (ganch) – 2%; liquid sodium glass – 12%; plasticizers CIT – 0,15%, SCS – 0,2%, LCR – 0,15%; modified hardener – 0,5% and water.

scholarly journals Investigation of fly ash properties with purpose of its utilization as a secondary raw material for portland cement clinker production

2006 ◽  
Vol 60 (9-10) ◽  
pp. 245-252 ◽  
Author(s):  
Zvezdana Bascarevic ◽  
Miroslav Komljenovic ◽  
Ljiljana Petrasinovic-Stojkanovic ◽  
Natasa Jovanovic ◽  
Aleksandra Rosic ◽  
...  
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Power Plants ◽  
Building Materials ◽  
Thermal Power ◽  
Cement Industry ◽  
Raw Material ◽  
Cement Clinker ◽  
Physical Chemical ◽  
Portland Cement Clinker

In this paper the results of the investigated properties of fly ash from four thermal power plants in Serbia are presented. The physical, chemical, mineralogical and thermal characterization of fly ash was carried out, in order to determine the possibility to utilize this material in the building materials industry, foremost in the cement industry. It was determined that, although there are differences concerning the physical, chemical, and mineralogical characteristics of the investigated samples, they are very similar concerning their thermal characteristics. It was concluded that using fly ash as one of the raw components in the mixture for Portland cement clinker synthesis, not only enables the substitution of natural resources, but it might have a positive effect on the lowering of the sintering temperature.

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