Sintered Glass-Ceramics, Self-Glazed Materials and Foams from Metallurgical Waste Slag.

Nicolai B Jordanov,Alexander Karamanov,Ivan Georgiev

doi:10.3390/ma14092263

Nicolai B Jordanov, Alexander Karamanov + Show 1 more

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https://doi.org/10.3390/ma14092263

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Abstract

The materials used for the synthesis of parent glass are 70% wt. metallurgical slag and 30% wt. industrial quartz sand. The initial batch is melted at and then quenched in water. The resulting glass frit is milled bellow 75 microns and pressed 1400 °C into “green” samples. In a next stage, they are heat treated at different temperatures with various heating rates and holding times. As a result, it is demonstrated the possibility for production variations, allowing the manufacture of three types of new materials by using the same pressed glass powders. We highlight the flexibility of the synthesis obtaining namely well densified glass-ceramics at about 950 °C, self-glazed glass-ceramics at about 1000 °C or glass-ceramic foams at approximately 1100 °C. The first set of materials is characterized by very well sintered structure combined with reasonable crystallinity; the second one—by smooth self-glazed surface with an attractive appearance and good properties and the third one—by 80–90% closed porosity and very good thermal stability above 1000 °C.

Highlights

We investigated the effect of CaF2 on the sintering ability and the foaming trend of the same base glass studied there
4.4.Conclusions thepresent presentinvestigation, investigation,we wedemonstrated demonstratedthe thepossibility possibilityfor forcarrying carryingout outsucsucInInthe cessfulsynthesis synthesisofofdifferent differentsintered sinteredmaterials materialsobtained obtainedfrom fromthe thesame sameglass, glass,products productsofof cessful vitrificationofofmetallurgical metallurgicalslag
The demonstrated technological flexibility is controlled by theheat heattreatment treatmentrates rates

Summary

Introduction

They are heat treated at different temperatures with various heating rates and holding times As a result, it is demonstrated the possibility for production variations, allowing the manufacture of three types of new materials by using the same pressed glass powders. After appropriate heat-treatment, the resulting glasses or frits are converted into final products such as traditional bulk glass-ceramics [1], sintered glass-ceramics [2,3] and glass-ceramic foams [4] This approach can be considered as a smart tool for the solution of problems concerning the storage and immobilization of various inorganic wastes [5,6].

Methods

Results

Conclusion