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

Geraldo Eduardo Gonçalves,Vanessa De Freitas Cunha Lins,Modestino Alves De Moura Brito,Sérgio Luiz Cabral Da Silva,Graziella Rajão Cota Pacheco

doi:10.1590/0370-44672014680117

Abstract

In cement production, which involves the production of cement clinker in rotary kilns, the main refractories used are magnesia-spinel bricks. These bricks may suffer infiltration by the clinker liquid phase, resulting in the corrosion of the spinel and the formation of low refractoriness mineralogical phases, such as the Q phase (C 20 A 13 M 3 S 3 ), which compromises refractory performance. Thus, the aim of this work is to correlate the infiltration resistance of magnesia-spinel bricks made from different grades of magnesia by clinker collected in three different cement plants (A, B and C). The purity of magnesia, besides its physical properties, strongly influences the proper ties and the infiltration resistance of magnesia-spinel bricks; as such the use of high grade magnesia is essential for producing high performance refractories.

Highlights

The refractory materials include a wide range of oxide or mixture of oxides as well as other materials such as carbon, carbides, nitrides and borides
The results indicate that cement clinker and alkali salts are two important agents that cause corrosion especially of the bonding phase of refractory in cement rotary kilns
The objective of this study is to correlate the infiltration resistance of magnesia-spinel refractory bricks made from different grades of magnesia by the clinker liquid phase, which is a gap in the literature about refractory bricks of magnesia-spinel

Summary

Introduction

The refractory materials include a wide range of oxide or mixture of oxides as well as other materials such as carbon, carbides, nitrides and borides. These materials exhibit superior physicochemical, thermodynamic and structural properties at elevated temperatures, such as a high melting point/refractoriness, resistance to chemical corrosion in an aggressive media, and structural stability (Liu et al, 2013). In the cement and 3% other components, and four industry, the manufacture of Portland main mineralogical phases identified as cement involves the steps of grinding the raw material (clay, limestone, bauxite, etc.), homogenization of the raw meal, C3S (3CaO.SiO2), C2S (2CaO.SiO2), C3A (3CaO.Al2O3) and C4AF

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Conclusion