Hyundai Steel and POSCO have reached yet another environmental milestone through their research on using exoskeleton waste, in the form of empty shellfish shells, as a secondary material for steel production.
After determining that the shells were similar in composition to the limestone used for sintering, Hyundai Steel and POSCO jointly studied different ways of substituting shells for limestone and submitted the results of their study to the Korea Environment Corporation for an Environmental Recycling Assessment¹. On August 15, after completing its assessment of the study results, the environmental organization approved the use of exoskeleton waste as a secondary material for steelmaking.
In steelmaking, sintering is a process in which powder-form iron ore is processed into sinters², which are then fed into a blast furnace. Limestone is used to give sinter its shape and allows for the control of the sinter’s composition.
In Korea, 300,000 to 350,000 tons of waste shells are generated each year and are typically left in piles throughout fishing communities. It is estimated that over 920,000 tons of waste shells have been left sitting for several years in fishing regions nationwide, causing environmental pollution in the form of water, dust, and unpleasant odors.
Recycling the waste shells by using them as a steelmaking material not only eliminates the environmental hazards caused by the piles of shells, but also allows steelmakers to cut steel production costs and reduce their use of limestone resources.
Hyundai Steel additionally developed a method of blending exoskeleton waste and limestone by-products into calcium oxide, which can be used as a secondary material in steelmaking for the removal of impurities.
Recycling the 920,000 tons of waste shells found lying around Korea’s fishing regions is equivalent to reducing Korea’s carbon dioxide emissions by 410,000 tons, or planting 300 million pine trees.
For Hyundai Steel, this achievement comes as part of its ESG efforts to cooperate with other entities for the creation of a “green cycle” of waste resources.
1) Environmental Recycling Assessment: Assessment of the recycling of a resource not previously recycled, and the impact of such recycling on the environment and human health
2) Sinter: Iron ore lumps of consistent sizes (5 mm to 50 mm) that can be fed into blast furnaces