Techno-economic analysis of a novel full-chain blast furnace slag utilization system

Abstract

As the main solid waste in the iron and steel industry, the waste heat recovery and comprehensive utilization of blast furnace slag had great significance for energy conservation and sustainable development. This paper proposed a novel full-chain blast furnace slag utilization system to solve the problem of waste heat recovery and high value-added production. Cascade recovery of slag waste heat was realized by using coal gasification reaction and the waste heat recovery ratio reached 73.61%. Meanwhile, two kinds of high value-added products of X-type zeolite and hydrotalcite-like compounds were synthesized simultaneously by using the beneficial components of blast furnace slag after fully recovering waste heat. Ultimately, the economic feasibility of the system was analyzed from two aspects of investment and profit. Under the reasonable economic assumptions, payback period of the project was 0.14 years, 10-year net present value was $ 326493.98 million, return on investment and internal rate of return were 737.74% and 312.82%, respectively. Through sensitivity analysis, the project could still be profitable in the production year under the condition that the sensitive factors of the system fluctuated within 40%. With great economic benefit and anti-risk ability, the novel full-chain blast furnace slag utilization system had potential in energy saving and emission reduction of iron and the iron and steel industry and the prospect of large-scale application.