Foam Glass Crystalline Granular Material from a Polymineral Raw Mix

Olga Miryuk,Mugahed Amran,Roman Fediuk

doi:10.3390/cryst11121447

Abstract

The article is devoted to the development of resource-saving technology of porous granular materials for energy-efficient construction. The relevance of the work for international research is to emphasize expanding the raw material base of porous lightweight concrete aggregates at the expense of technogenic and substandard materials. The work aims to study the processes of porization of glass crystalline granules from polymineral raw materials mixtures. The novelty of the work lies in the establishment of regularities of thermal foaming of glass crystalline granules when using waste of magnetic separation of skarn-magnetite (WMS) ores and lignite clay. Studies of liquid glass mixtures with various mineral fillers revealed the possibility of the formation of a porous structure with the participation of opoka, WMS and lignite clay. This is due to the presence in the materials of substances that exhibit thermal activity with the release of a gas phase. The foaming efficiency of the investigated materials increases when combined with glass breakage. The addition of WMS and lignite clay to the glass mixture increases the pore size in comparison with foam glass. The influence of the composition of raw mixtures on the molding and stability of granules is determined. The addition of sodium carbonate helps to strengthen the raw granules and reduce the softening temperature of the mass. The composition of the molding mixture of glass breakage, liquid glass and a multicomponent additive is developed, which provides an improvement in the molding properties of the glass mass, foaming of granules at a temperature of 750 °C. Foam glass crystalline granules have polymodal porosity, characterized by a density of 330–350 kg/m3, a compressive strength of 3.2–3.7 MPa, and a thermal conductivity of 0.057–0.061 W/(m·°C). Accordingly, the developed granules have a high potential use in structural and heat-insulating concretes.

Highlights

An important stage of technology that provides building materials with a decrease in density, thermal insulation and acoustic properties, is the formation of a porous structure
Foaming is a common method of forming pores and is implemented in the technology of cellular concrete [1,2,3], porous granular and composite materials [4]
Porous materials from silicate glasses are produced in the form of piece products [8] and granules used as a filler for lightweight concrete and heat-insulating backfills [9]

Summary

Introduction

An important stage of technology that provides building materials with a decrease in density, thermal insulation and acoustic properties, is the formation of a porous structure. A number of developments are devoted to highly porous granular materials based on thermal foaming of liquid glass [57]. The aim of the work is to study the effect of the material composition of the raw mixture on the formation and properties of glass-ceramic foam granules using technogenic materials of various origins. To achieve this aim, the following tasks have been identified:. − Study of the effect of mineral additives on thermal transformations of glass mass; − Research of the processes of formation of a porous structure during the firing of mixtures of various compositions; − Study of the structure and properties of expanded granular materials. Waste from magnetic separation of skarn-magnetite ores and lignite clay as raw materials of glass-crystalline charge were studied for the first time

Mix Design

Laboratory Equipment and Research Methods

Thermal Foaming of Materials