Integrated optimisation of blast furnace gas wash water treatment, reuse and cost savings Part I: Methodological approach

Within a European collaborative research project aimed at improving resource efficiency and environmental sustainability in steelmaking plants, simulations have been applied to evaluate integrated solutions for water recycling, reuse and treatment at a blast furnace gas wash plant. The blast furnace gas washing process, in steelworks, is a major water consumer and significant contributor to water pollution. A two paper series describes the research undertaken at a Tata Steel blast furnace plant (UK) in collaboration with Process Integration Limited (UK) to model and simulate process integration options for improving water quality, increasing water conservation by reuse, maximising energy efficiency and reducing treatment and operating costs. This paper constitutes the first part which introduces the system and describes the underlying issues and opportunities that have been considered in this study. It also provides a methodological framework and defines the base case for the study. Thereafter simulation results for recycle-reuse analysis (without treatment) are discussed and it has been concluded that some form of treatment is essential in order to achieve the stated objectives. Reverse osmosis and magnetic filtration treatment are identified as the suitable options in this regard. Their field trials and subsequent analysis of various regeneration-reuse scenarios and their techno-economic evaluation have been discussed in the second part of the paper.