Interaction between magnesia-spinel refractory grains and cement clinker at high temperature

2017 ◽  
Vol 53 (2) ◽  
pp. 319-327
Author(s):  
Sun Liang ◽  
Xiao Yougang ◽  
Li Yun ◽  
Yang Shenghai ◽  
Deng Wei
Keyword(s):  
High Temperature ◽  
Cement Clinker ◽  
Spinel Refractory ◽  
Magnesia Spinel

Mineral Waste Coupled with Boron Oxide for Producing Active Belite Cement Clinker

2013 ◽  
Vol 405-408 ◽  
pp. 2564-2575
Author(s):  
Yan Jun Liu ◽  
Yong Chao Zheng
Keyword(s):  
High Temperature ◽  
Boron Oxide ◽  
Tricalcium Silicate ◽  
Dicalcium Silicate ◽  
Cement Industry ◽  
Cement Clinker ◽  
Strength Development ◽  
Complete Replacement ◽  
Belite Cement ◽  
Mineral Waste

This paper presents a laboratory study on active belite cement clinker using boron oxide as dopant to stabilize high temperature phases of Dicalcium silicate (C2S), and mineral waste as siliceous materials in complete replacement of clay. The clinker samples were soaked in Muffle Furnace at different burning temperatures and for various time durations, and then, cooled down to room temperature using air blower. Quantitative X-ray Diffraction analysis (QXRD) by Rietveld method indicates that major mineral components are Dicalcium Silicate (C2S), Ferrite (C2 (A0.48F1.52) O5) and trace amount of Tricalcium Silicate (C3S) in the cement clinkers. Among them, Dicalcium silicate is over 85 percent, Ferrite around 10 percent and Tricalcium silicate less than 10 percent. Thermogravimetric and Differential Scanning Calorimetric (TGA-DSC) spectrum shows that there is no significant phase change while cement clinker was cooling down, which means significant amount of high temperature polymorphic C2S was stabilized during cooling process. It is agreeable with the results from QXRD analysis. Specifically, among polymorphic belite phases, αH-C2S accounts for around 66% of cement clinker, and αL-C2S for about 22% of cement clinker. In addition, massive belite phase was identified by Scanning Electronic Microscope (SEM) analysis and Light Microscopy analysis. At last, the mechanical tests on active belite cement show that active belite cement clinker has a slow strength development at early ages, but rapid strength gain at 28 days in comparison with belite clinker without adding boron oxide. Thus, this active belite cement clinker demonstrates very promising prospect in sustainable cement industry development. Keywords: Active Belite Cement Clinker; Doped; Boron Oxide; αH-C2S; αL-C2S; Strength Development

Active Belite Cement Clinker Produced with Mineral Waste

2012 ◽  
Vol 610-613 ◽  
pp. 2378-2385 ◽  
Author(s):  
Yan Jun Liu ◽  
Yong Chao Zheng
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Mechanical Tests ◽  
Tricalcium Silicate ◽  
Dicalcium Silicate ◽  
Cement Industry ◽  
Cement Clinker ◽  
Strength Development ◽  
Belite Cement ◽  
Mineral Waste

This paper presents a laboratory study on active belite cement linker using mineral waste as one of the major raw meal components. The main chemical component of mineral waste employed in this study is silica (SiO2), around 70%. The raw meals were soaked in Muffle Furnace at 1350oC for 10 minutes and 20minutes respectively, then, cooled down to room temperature using air blower. Boron Oxide was used to stabilize high temperature phases of C2S. QXRD analysis indicates that active belite cement clinker has major mineral components consisting of Dicalcium Silicate (C2S), Ferrite (C2 (A0.48F1.52) O5) and trace amount of Tricalcium Silicate (C3S). Among them, Dicalcium silicate is over 85 percent, Ferrite around 10 percent and Tricalcium silicate less than 10 percent. Also, significant amount of high temperature polymorphic C2S was stabilized under room temperature. Among polymorphic belite phases, αH-C2S accounts for around 66% of cement clinker, and αL-C2S for about 22% of cement clinker. Scanning Eαlectronic Microscope (SEM) analysis also shows coαnsiderable round grains of C2S. TGA-DSC spectrum indicated there is no significant phase change while cement clinker was cooling down. Also, the mechanical tests on active belite cement show that active belite cement clinker has a slow strength development at early ages, but rapid strength gain over 70Mpa at 28 days. Thus, this active belite cement clinker demonstrates very promising prospect in sustainable cement industry development.

scholarly journals Influence of magnesia in the infiltration of magnesia-spinel refractory bricks by different clinkers

2015 ◽  
Vol 68 (4) ◽  
pp. 409-415 ◽  
Author(s):  
Geraldo Eduardo Gonçalves ◽  
Graziella Rajão Cota Pacheco ◽  
Modestino Alves de Moura Brito ◽  
Sérgio Luiz Cabral da Silva ◽  
Vanessa de Freitas Cunha Lins
Keyword(s):  
Spinel Refractory ◽  
Magnesia Spinel ◽  
Refractory Bricks

High Performance Iron-Rich Magnesia-Spinel Composite for Burning Zone of Cement Rotary Kiln

2012 ◽  
Vol 476-478 ◽  
pp. 1915-1919 ◽  
Author(s):  
Guo Xiang Yin ◽  
Yong Li ◽  
Jun Hong Chen ◽  
Bo Pan
Keyword(s):  
High Temperature ◽  
Rotary Kiln ◽  
High Performance ◽  
Adhesion Property ◽  
Modulus Of Rupture ◽  
Diffusion Reaction ◽  
High Temperature Strength ◽  
Sintered Iron ◽  
Burning Zone ◽  
Magnesia Spinel

The structure and properties of iron-rich magnesia-spinel composite prepared using sintered iron-rich magnesia and MgO-rich spinel for burning zone of cement rotary kiln were analyzed. The results show that fine-grained magnesioferrite precipitation and magnesiowustite improved the flexibility of magnesia. The formation of Mg (Al,Fe)2O4 reaction rim between iron-rich magnesia and MgO-rich spinel by inter-diffusion reaction of Fe3+ and Al3+ improved the direct-bonded degree and high temperature strength. At high temperature, Fe3+ diffused into the grain of periclase of MgO-rich spinel and was precipitated in the from of magnesioferrite during cooling, which strengthened the structure flexibility of MgO-rich spinel. Iron-rich magnesia-spinel composite had a good adhesion property to clinker because of the uniform distribution of FeOn. Under the same content of Al2O3 and Fe2O3, the iron-rich magnesia-spinel composite had higher hot modulus of rupture, better thermal shock resistance and adhesion property to clinker compared to MgO-spinel composite and MgO-hercynite composite.

scholarly journals MlNERALOGICAL STUDY AND PROPERTIES OF MAGNESIA REFRACTORIES DERIVED FROM EVIAN MAGNESITE

2004 ◽  
Vol 36 (1) ◽  
pp. 97 ◽  
Author(s):  
P. Lampropoulou ◽  
C. Katagas
Keyword(s):  
High Purity ◽  
Raw Materials ◽  
World Market ◽  
Cement Industry ◽  
Refractory Materials ◽  
Secondary Phases ◽  
High Position ◽  
Spinel Refractory ◽  
Magnesia Spinel ◽  
Group B

In order for the Greek magnesia industry to retain a high position in the world market, the basic refractories derived from Greek magnesite must remain at the forefront of the international developments. A mineralogical study of magnesia materials produced from Evian magnesite has been carried out with the aim a) to provide detailed characterization of products and microstructures derived from the firing processes of magnesia raw materials and b) to contribute to the development of new magnesia-spinel refractory materials from natural Greek magnesite. The magnesite of N. Evia, Greece, is micro- crystalline and has been used for the production of basic refractories because of the very low amounts of impurities such as CaO, S1O2, FeO(tot), B2O3 it contains . Magnesia materials studied here are: 1) Raw materials. The dead- burned magnesia grains examined are divided into two groups according to the mode of beneficiation of the raw magnesite: a) Dead burned magnesias produced from natural microcrystalline magnesite (Group A). b) Dead burned magnesias of high purity produced from natural microcrystalline magnesite (Group B). The chemical composition of these materials lies essentially in the MgO-CaO-SiC>2 system, since they contain only trace amounts of Fe2Û3 and AI2O3. Their microstructures vary widely in terms of proportions of direct MgO-MgO bonding, amounts and types of phases of the siliceous bonding and size of the periclase crystals. Dead burned magnesias of high purity are better sintered and contain lower amounts of secondary phases compared to magnesias of lower purity. 2) Commercial magnesia bricks derived from dead burned magnesia of high purity and magnesia chromite bricks derived from raw materials of dead burned magnesia of high purity and chromite from Africa. 3) New spinel-based composition and new magnesia-spinel refractory materials which have been synthesized for the needs of this study. The newly synthesized spinel-based composition (70wt% Al2O3-30wt% MgO) shows an increase in the bulk density as well as in the amount of spinel formed compared to available commercial qualities (50%wt AI2O3). 4) Using this new spinel-based composition and dead burned magnesia of high purity, two new magnesia-spinel refractory materials containing 10 and 20wt% AI2O3 were produced, with the aim to obtain more friendly to the environment magnesia refractories to substitute for the magnesia chromite bricks. The compositions of the magnesia spinel refractories thus produced were expected to show endurance in thermal shocks as well as in the corrosion from slags and friction, in order to have a wide application in steel, cement industry etc .

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