Preparation of Low-Heat Portland Cement Clinker with Coal Gangue

2011 ◽  
Vol 306-307 ◽  
pp. 861-864
Author(s):  
Guang Li Chen ◽  
Xing Hua Fu ◽  
Wen Hong Tao

A kind of low-heat Portland cement clinker was prepared with coal gangue, limestone and gypsum through optimizing the mix proportion of raw materials, and its properties and hydration characteristics were studied. The results showed that the cement clinker meeting the demands of mid (low)-heat Portland cement standard could be prepared with 35% (by weight, the same below) coal gangue, 57-60% limestone and 6-8% gypsum. The raw materials were burned at 1380°C for 40 minutes. The main hydrates were calcium silicate hydrate (C-S-H) gel, ettringite (AFt), monosulfate (AFm) and Ca(OH)2.

2020 ◽  
Vol 989 ◽  
pp. 221-227 ◽  
Author(s):  
O.Yu. Sheshukov ◽  
I.V. Nekrasov ◽  
Denis K. Egiazaryan

Synthesis of the portland cement clinker in the presence of a significant amount of SO3 is difficult, due to the tri-calcium silicate formation suppression. Since some technogenic formations contain a significant amount of SO3, it is hard to obtain the portland cement clinker from it. The analysis of the SO3 influence on the clinker-formation thermodynamic process allowed to reveal a number of regularities of their occurrence and to propose a method for the raw mix composition calculating and its preparation, to ensure a stable portland cement clinker synthesis.


2015 ◽  
Vol 814 ◽  
pp. 435-440 ◽  
Author(s):  
Jia Ping Cui ◽  
Yu Liu ◽  
Zhi Hong Wang ◽  
Xian Zheng Gong ◽  
Feng Gao ◽  
...  

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.


Author(s):  
М.Ш. Саламанова ◽  
С.А. Алиев ◽  
Р.С.-А. Муртазаева

В процессе обжига портландцементного клинкера в электрофильтрах вращающихся печей скапливается большое количество пыли, как клинкерной, так и аспирационной, поэтому рациональное использование этих продуктов, содержащих определенную долю полноценного сырьевого ресурса, является актуальной задачей индустрии цемента. В данной работе представлены результаты исследований цементной пыли, проведен энергодисперсионный и сравнительный анализ исследуемых порошков, а также приводится возможный способ утилизации цементной пыли для получения бесклинкерных цементов щелочной активации и бетонов на их основе. Разработанные рецептуры бесклинкерных вяжущих с применением отходов цементной промышленности и натриевого жидкостекольного затворителя позволят получать менее затратные, прочные и долговечные композиты, которые позволят частично заменять традиционный бетон на дорогом портландцементе. Работа выполнена в рамках исследований по реализации научного проекта 1848200001 Высококачественные бетоны с повышенными эксплуатационными свойствами на основе местного природного и техногенного сырья , получившего поддержку Российского фонда фундаментальных исследований (РФФИ). In the process of firing Portland cement clinker in electrostatic precipitators, in rotary kilns, a large amount of harmful substances, both clinker and aspiration, accumulates, therefore rational use of these products leads to certain shares of a fullfledged river resource, which are derived from industrial cement. It should be noted that the reuse of dust electrostatic precipitators is impossible. The basis for obtaining durable and more resourceefficient composites is based on modern technological methods that contribute to the improvement of technical and physicomechanical properties, with the integrated application of technogenic raw materials and liquid sodium binder. The developed clinkerfree binder formulations using the cement industry wastes and sodiumbased sludge glass will make it possible to produce less expensive, durable, and durable composites that will partially replace traditional concrete with expensive portland cement.


2012 ◽  
Vol 730-732 ◽  
pp. 94-99 ◽  
Author(s):  
Maria Margarida Rolim Augusto Lima ◽  
L.F.C. Braz ◽  
Regina da Conceição Corredeira Monteiro ◽  
J.P. Veiga

Phosphogypsum (PG) is a pollutant residue resulting from the production of phosphoric acid in the phosphated fertilizers industry. About 180 millions of tons of PG are generated worldwide per year, which originates storage problems because of the environmental restrictions and the high costs of storage spaces. Taking into account the mineralizer properties of PG it has been studied a way to valorize this residue as an alternative material in the production of Portland cement clinker. The PG and the raw-materials (limestone, marl, sand and iron oxide) were chemical, mineralogical and thermally characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD) and differential thermal analysis and termogravimetric analysis (DTA/TGA). After milling, the phosphogypsum was mixed with the raw-materials in different amounts up to 10% weight. The raw mixtures were submitted to two types of firing schedules, heating up to 1500°C without any holding time or heating up to 1350°C and holding for 20 minutes. After firing, the clinkers were analyzed by optical microscopy, milled and characterized in terms of chemical and mineralogical compositions. The clinkers were used to produce cement mortar according to NP EN 196-1 standard. The resultant test specimens were mechanically tested at 2 and 28 days according to the same standard. The obtained results show a reduction of about 140°C in the clinkerization temperature, when a raw mixture with 5% phosphogypsum was used. Standard clinkers, without phosphogypsum addition, which were fired at 1500°C, originated test specimens with a compressive strength of 48.1MPa at 28 days. Test specimens produced with clinker containing 5% phosphogypsum present higher compressive strength values at 28 days, being 55.1MPa for clinkers produced at 1500°C, and 49.4 MPa for clinkers produced at 1350°C.


2021 ◽  
Vol 6 (3) ◽  
pp. 65-71
Author(s):  
Nikita G. Reznikov ◽  
◽  
Alexander G. Zhikharev ◽  

The article discusses the construction of a simulation model of the abstract process of converting raw materials into Portland cement clinker in the UFOModeler simulation environment. An algorithm for generating a pseudo-random oxide (chemical) composition of components based on experimental data of real production and calculation for two-component and three-component raw mixtures has been developed. An algorithm for calculating the main indicators of the composition of clinker based on. The analysis of the obtained results is carried out.


2019 ◽  
Vol 16 (3) ◽  
pp. 352-365
Author(s):  
A. K. Matyeva

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.


2014 ◽  
Vol 1065-1069 ◽  
pp. 1950-1956
Author(s):  
Sha Ding ◽  
Guo Zhi Zhang ◽  
Fei Xiang Chen

supersulphated phosphogysum-slag cement (SSC) is a newly developed non-burned cementitious material. It’s mixed and ground with 40%-50% phosphogypsum, 40%-50% ground granulated blast-furnace slag (GGBFS), 2% steel slag and 4% portland cement clinker. But the component of SSC differs greatly from that of Portland cement, there is few application researches about the SSC. In order to realize resourceful utilization of phosphogypsum, the mix proportion design method of SSC are studied. The mix proportion design method for C30 are systematically studied and a design optimization was carried out. According to the design regulations of mix proportion of ordinary concrete and the characteristics of SSC, the C30 high flowing concrete is prepared, and the optimum water-cement ratio is obtained based on revised Bowromi formula. According to the mix proportion optimization design, the 28d strength of SSC is up to 38.5MPa.


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