Removal of Residual Element Tin in the Ferrous Metallurgy Process: A Review

Abstract

With the continuous improvement of the quality of steel for social development, high-quality iron ore resources have been gradually depleted. Meanwhile, the scrap steel reserve and recycling volume are gradually increasing, which will result in the continuous increase of the residual tin content in steel, which seriously restricts the improvement of steel quality and the circulation-utilization of scrap. Therefore, it is necessary to remove as much tin as possible in the ferrous metallurgy process. However, tin in steel cannot be effectively removed in the conventional smelting process. In this paper, the origination, the existing forms, and the content control levels of the residual tin in steel are presented, as well as the current processes of tin removal in the ferrous metallurgy process.

International comparison of impurities mixing and accumulation in steel scrap

“…Sn content values are impacted by the number of values under the DL, meaning that the content is overestimated. However, the Sn tolerance limit in the Chinese standard for low‐carbon steel plates is higher than in the standards of other countries: this has been attributed to the consumption of locally produced tin‐bearing iron ore and ferroalloys (Zhang et al., 2019). It is therefore reasonable to expect the Sn content to be impacted by material input during production.…”

“…are oxidized to slag during the refining of scrap, others remain in the molten steel. The technologies developed to eliminate these so‐called tramp elements from molten steel have been reviewed (Daehn et al., 2019; Zhang et al., 2019), but their application in current metallurgical processes is limited. In particular, Cu, Sn, Ni, and Mo present challenges for steelmaking (Nakajima et al., 2011; UNEP, 2013).…”

Circular Steel: How Information and Actor Incentives Impact the Recyclability of Scrap

“…In scrap charge optimization, the presence of unwanted elements may lead to deviation from the product standard [88] Physical condition That pieces are cut to size or are aggregated by pressing or briquetting to reduce difficulty in using loose pieces of scrap [74,89] Moisture and organic matter interfere with the removal of residual tin via chlorination [90] Shape and size Density High-density scrap is preferred when loading buckets [91]…”

“…Again, the industry has preferences regarding how scrap should be delivered. Consider moisture: in colder areas, the concern is the risk of explosion [109], but it can also interfere with the removal of residual tin via chlorination [90]. Thus, while there is no universal definition of scrap quality, guidelines such as the scrap book and other steel scrap specifications exist to facilitate trading [5] in a way that reflects industry need-defined by steel recycling actors, for actors.…”

Microstructure evolution and tensile behaviour of a cold rolled 8 wt\% Mn medium manganese steel

“…V can also be added for carbide formation and precipitation strengthening [14,28] but its content should ideally be kept below 0.1 wt% to minimise the alloying cost of the steel. Lastly, even though Sn is a known tramp element in steel [29], 0.05 wt% Sn was deliberately added to potentially improve the galvanisability of the steel [30].…”