Pilot Tests for the Comprehensive Utilization of Coal Refuse to Produce Alumina and Cement Clinker

2012 ◽  
Vol 557-559 ◽  
pp. 854-859
Author(s):  
Qiu Guo Xiao ◽  
Shao Bin Xiang ◽  
Shao Hua Shen
Keyword(s):  
Laboratory Tests ◽  
Raw Materials ◽  
The Other ◽  
Cement Clinker ◽  
Comprehensive Utilization ◽  
Portland Cement Clinker ◽  
Laboratory Results ◽  
Temperature Regimen ◽  
Coal Refuse ◽  
Pilot Tests

This paper describes a pilot process for the comprehensive utilization of coal refuse. During the process, alumina was first extracted from coal refuse, the residue was then used to calcine cement clinker, and all of the waste gases and water were recovered and re-used in the process of alumina extraction. During the first process, the appropriate temperature regimen and temperature distribution were determined based on laboratory results in a tunnel kiln, and were optimized during the pilot process. The most important step of the temperature regimen is the increasing rate within the temperature range of 500–600°C. And the last determined temperature regimen is suitable to be used in the other industrial kiln when the other processes are applied for the extraction of alumina from coal refuse. The extraction rate for alumina has also been investigated in the pilot tests, and it is a bit lower than those obtained in the laboratory tests. Two methods were used for the calcination of cement clinker. The clinker calcined directly from the adjusted residue could be used for applications with low strength demands, whereas the clinker calcined from the residue and the raw materials of the Portland cement clinker could be used normally.

scholarly journals Moroccan oil shale and coal waste as alternative raw materials in Portland cement clinker manufacture. Clinkerisation reactions and clinker characterisation

2018 ◽  
Vol 68 (331) ◽  
pp. 166
Author(s):  
S. Chhaiba ◽  
M. T. Blanco-Varela ◽  
A. Diouri
Keyword(s):  
Particle Size ◽  
Oil Shale ◽  
Raw Materials ◽  
Cement Industry ◽  
Cement Clinker ◽  
Waste Materials ◽  
Coal Waste ◽  
Energy Costs ◽  
Portland Cement Clinker ◽  
Cement Manufacture

For some time the cement industry has been seeking procedures to effectively lower the higher energy costs involved in cement manufacture. Timahdit oil shale and Jerada coal waste could potentially be used as alternative raw materials to produce clinker. This study explored the possibility of applying those materials to a greener use, based on the reactivity and burnability of raw mixes containing Moroccan oil shale and coal waste. The findings showed that, irrespective of particle size, oil shale mixes delivered higher reactivity than coal waste materials, although reactivity was highest in the oil shale clinker with a particle size < 45 μm. The clinkers bearing oil shale with a particle size < 90 μm or a blend of oil shale and coal waste with a size < 45 μm contained higher proportions of alite ( > 70 %).

scholarly journals METHODS OF REPEATED USE OF CEMENT DUST

2019 ◽  
Author(s):  
М.Ш. Саламанова ◽  
С.А. Алиев ◽  
Р.С.-А. Муртазаева
Keyword(s):  
Portland Cement ◽  
Raw Materials ◽  
Cement Industry ◽  
Cement Clinker ◽  
Liquid Sodium ◽  
Portland Cement Clinker ◽  
Repeated Use ◽  
Electrostatic Precipitators ◽  
Rotary Kilns ◽  
Technogenic Raw Materials

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.

Life Cycle Assessment of Comprehensive Utilization of Calcium Carbide Slag in Cement Kiln

2020 ◽  
Vol 993 ◽  
pp. 1487-1495
Author(s):  
Xin Ping Lin ◽  
Ai Wei Liu ◽  
Yun Fa Feng ◽  
Qi Ling Chen ◽  
Tao Chen ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Emission Reduction ◽  
Calcium Carbide ◽  
Cement Industry ◽  
Cement Clinker ◽  
Cement Kiln ◽  
Cement Production ◽  
Comprehensive Utilization ◽  
Carbide Slag ◽  
Portland Cement Clinker

The recycling utilization of solid waste is an important technical means for the sustainable development of the cement industry in China. Calcium carbide slag is a special solid waste in China, which can be used for cement production with a great advantage on CO2 emission reduction. With an view to providing methodological and data support for the development of policies in the cement industry, this paper quantitatively analyzes the environmental effects/environmental benefits of the comprehensive utilization of calcium carbide slag in cement kiln by comparing the traditional system of Portland cement clinker completely produced by natural resources with the system of cement clinker produced by calcium carbide slag based on the life cycle assessment (LCA) method given in standards and specifications of ISO 14040 series. The results show that the latter system has a better effect in material saving and carbon emission reduction, will increase the energy consumption in cement production process, and also slightly increase other pollutants (e.g. SOx, NOx, etc.) emission. The GWP, AP and EP indicators of the calcium carbide slag cement clinker system decrease compared with those of the Portland cement clinker system, while other indicators do not differ much or even slightly increase.

Effect of Phosphogypsum on the Clinkerization Temperature of Portland Cement Clincker

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
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Raw Materials ◽  
Cement Clinker ◽  
X Ray Diffraction ◽  
X Ray ◽  
Portland Cement Clinker ◽  
Alternative Material ◽  
Heating Up ◽  
Mineralogical Compositions

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.

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
Keyword(s):  
Portland Cement ◽  
Calcium Silicate ◽  
Calcium Silicate Hydrate ◽  
Raw Materials ◽  
Coal Gangue ◽  
Cement Clinker ◽  
Mix Proportion ◽  
Portland Cement Clinker ◽  
Hydration Characteristics

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.

scholarly journals Application of the system-object approach to simulation of the conversion of raw materials into a portlandcement clinker

2021 ◽  
Vol 6 (3) ◽  
pp. 65-71
Author(s):  
Nikita G. Reznikov ◽  
◽  
Alexander G. Zhikharev ◽  
Keyword(s):  
Experimental Data ◽  
Chemical Composition ◽  
Portland Cement ◽  
Simulation Model ◽  
Raw Materials ◽  
Cement Clinker ◽  
Simulation Environment ◽  
Portland Cement Clinker ◽  
Two Component

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.

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.

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