PHYSICAL AND CHEMICAL PROPERTIES OF GRANULATED SLAG AND THEIR INFLUENCE ON HYDRAULIC ACTIVITY

Abstract

Granulated metallurgical slags are a large-scale by-products of metallurgical production, with annual global production volumes reaching hundreds of millions of tons. As the construction industry transitions to low-carbon technologies, these materials are becoming increasingly important as an effective alternative to Portland cement. This paper presents a comprehensive review of the physicochemical properties of granulated slags and the factors determining their hydraulic activity. This article systematizes information on the technological aspects of slag production, including a comparative analysis of wet, semi-dry, and dry granulation methods. Their crucial role in the formation of an amorphous glassy structure – a key condition for the development of binding properties. The oxide and mineral composition of various slag types (blast furnace, electrothermal phosphorus, ferrochrome, and steelmaking) is examined in detail. Quantitative criteria for assessing hydraulic activity are presented, including the basicity module, quality factor, and hydraulic index. It has been established that blast furnace slags with a glass phase content of 74–94%, a basicity module of 0.9–1.2, and a specific surface area greater than 3500 cm²/g exhibit maximum reactivity. An analysis of current international research demonstrates the feasibility of creating alkali-activated binders demonstrating compressive strength up to 105 MPa with up to 50% of the slag replaced with inert fillers. Particular attention is paid to environmental aspects: the use of alkali-activated slag binders reduces CO₂ emissions by 60–70% and energy consumption by up to 67% compared to traditional cement production. This paper summarizes current understanding of the relationship between the composition, structure, and properties of granulated slags, providing a basis for the targeted design of composite binders with specified performance characteristics.