Chemical and mineralogical characterization of silicon manganese iron slag as railway ballast

Abstract

In nature, metal ores such as iron, lead, aluminum and others are found in an impure state, sometimes oxidized and mixed with silicates of other metals. During casting, when the ore is exposed to high temperatures, these impurities are separated from the molten metal and can be removed. The mass formed by these compounds is slag. Slag is the co-product of the smelting of ore to purify metals. It may be considered a mixture of metal oxides, but may also contain metal sulphites and metal atoms in their elemental form. After it is reprocessed to separate the metals contained, the co-products of this process can be used in cement, rail ballast, road paving and various other purposes. The objective of this research work is the presentation of the chemical and mineralogical characterization tests of the silicon-manganese iron slag with the purpose of reusing the coproduct as rail ballast. X-ray diffraction tests, quantitative chemical analyzes, scanning electron microscopy and free lime content were prepared for these characterizations. The results of these tests showed the technical feasibility of using slag as rail ballast.

The global iron industry and the Anthropocene

“…The annual global output of iron slag (BOF, BF, LF, and EAF routes) is estimated to be around 310–370 Mt and 170–250 Mt for steel slag (USGS, 2015). After production, it is either deposited in slag pits and storage yards, recycled, or further used in asphalt mixtures, railway ballast, embankments, unbound base courses, or as an alternative agricultural lime (Oliveira et al, 2017; Riley et al, 2020). The reutilization rate of slag can be up to 100% (Japan, Germany, USA, France, etc.)…”

“…As iron ore naturally contains impurities, the removal of such during high-temperature casting processes creates iron slag. It is mostly a mixture of metal oxides but often includes metal sulphites and metal atoms in their elemental state (Oliveira et al, 2017). The annual global output of iron slag (BOF, BF, LF, and EAF routes) is estimated to be around 310-370 Mt and 170-250 Mt for steel slag (USGS, 2015).…”

Effect of Chemical Treatment on Silicon Manganese: Its Morphological, Elemental and Spectral Properties and Its Usage in Concrete

“…It is also worth noting that for SMC, the interaction between sand and other materials is correctly combined, resulting in better samples. produce a special needle fascinated shape, resulting in a rougher and more readily absorbent surface [53]. When comparing Figures 3 (c) and 3 (d), it can be shown that the acidic concentration and composition appear to eliminate unwanted weak structures, resulting in a small amount of porous structure on the surface [53].…”

Prediction model for hardened state properties of silica fume and fly ash based seawater concrete incorporating silicomanganese slag

“…Using the predicted strength of SiMn slag concrete, the compressive strengths of limestone concrete were obtained from Eqn. (2).…”

“…It is uncomplimentary for the smelting plant to store a large amount of waste due to uneconomical and spacedemanding reasons. This waste is usually disposed of by landfill and sometimes used as road paving materials [2]. Nonetheless, SiMn slag has recently been substituted as materials for concrete production.…”