ENHANCING THE SUSTAINABILITY OF FUNCTIONAL GLASSES

Throughout industrial advancement, substantial quantities of industrial glass waste are produced, carrying significant potential for utilization. Utilizing such waste to prepare cold, consolidated, dense, and porous construction blocks using weak alkali activation represents a prevalent approach to resource recycling, offering promising applications in pollution adsorption and construction materials. The aim of research is to enhance the sustainability of functional glasses by synthesizing complex industrial glass waste into construction material using a minimal number of additives and mild alkali activation, followed by scrutinizing their diverse functional attributes, such as compressive strength, porosity, and thermal conductivity, among others. The alkaline activation is a process to produce suspensions of fine glass powder in dilute alkali solutions. Hardening occurs through cold consolidation at a low temperature of 40 °C. The key feature of this process is the surface condensation reactions on the hydrated layers of glass particles, forming strong Si–O–Si and Al–O–Si bonds that ensure material integrity. Simultaneously, dissolved glass components reorganize into a secondary phase comprising newly formed gel, crystalline phases, and alkaline carbonates. An effective direct foaming was achieved through vigorous mechanical stirring of partially gelled suspensions, including both foaming agent and surfactant. The resulting foam microstructure, total porosity, and cell size were dependent on the degree of gelation; a subsequent sintering step was applied at relatively low temperatures, ranging from 700 to 900 °C, with an end-of-life perspective. The method demonstrated significant versatility, as it was successfully adapted to a wide range of glass waste types and industrial waste mixtures, each resulting in the formation of distinct gels upon alkali activation. The alkali activation of soda-lime waste glass was achieved by mixing it with alumina powder and an iron-alumina-rich inorganic waste sourced from refractory materials. Glass foams from mixture of borosilicate glass originating from production scrap by the company and glass mud from drilling and grinding of glass kitchen tops. This strategy was further broadened to include other glass-based waste materials, such as vitrified bottom ash derived from the incineration of municipal solid waste. To optimize the process and tailor the properties of the resulting matrix, a comprehensive investigation into various processing parameters was conducted. This included systematic variations in the use of surfactants, drying conditions, thermal treatment, and water-to-solid ratios. Through this extensive investigation, a deeper understanding of the interplay between these parameters and the final material characteristics was achieved, highlighting the adaptability and potential scalability of the approach for diverse waste streams.