Abstract Coal blend bulk density is an important property in the coking process. Some variables, such as moisture and particle size, which are controlled or measured in the coal beneficiation process in steel mills, exert a strong influence on this feature. This study aims to understand the density variation of coal blends by the influence of moisture and particle size when using dry and wet bases. The investigations showed that higher density can be reached when drying the coal blend or even with excess of moisture by an agglomeration process. However, for a coal blend of lower moisture content, such as 4%, the better effects on the coking process are evident. Changes on the density from particle size require care, since they can fall in a region of high density achieved by larger particles or in a region with excess coal fines, where either or both can compromise the coke quality.

Abstract The demand for sustainable materials in the steel industry and the search for alternatives for the traditional ferriferous burdens utilized in siderurgy stimulated the development of this research. The briquetting process is a usual measure taken for recycling materials such as ironmaking waste (dust and sludge from blast furnaces), which can be reutilized in steel plants. The objective of this article is to investigate the influence of the use of organic and inorganic binders, blast furnace dust and sludge on the mechanical strength of briquettes for use in blast furnaces. The mechanical analysis was performed with the results from tumbling tests, executed to obtain the strength of each sample composition. The results exhibited adequate values of mechanical strength for samples that contained BBTL and BBTX binder, indicating that these materials acted as good binders in the briquetting process.

The use of scrap tires in the coal blends is an alternative to reduction of coke production costs as well as mitigates the impact caused by tire accumulation in the environment. Tests were carried out on a pilot scale, with coal blends and waste tire in 4 levels and 3 particle sizes, in order to assess the impact on the produced coke quality, especially on the Strength after Reaction with CO2 - CSR and Drum Index (DI150-15). In addition, it evaluated the mechanical resistance to compression, punctual chemical composition by Energy Dispersive Spectroscopy (EDS) analysis beyond the carbonaceous matrix-tire interface by SEM microscopy. The results from the coking tests showed that addition of up to 3% of the average ground tire (20-30mm) with steel mesh, raised either as CSR DI150-15, making feasible added also from a technical point of view.