Recent progress in sustainable and energy-efficient technologies for sinter production in the iron and steel industry

Zajemska

Clean Techn Environ Policy

et al. 2021

The article presents innovative technology which integrates a metallurgical pusher-type furnace with a waste heat recovery system that consisted of a reactor for torrefaction and pyrolysis of waste biomass. The technology is designed for utilizing both liquefied and gaseous by-products (torgas, pyrolysis gas and condensate denoted as TPC) obtained from torrefaction and pyrolysis of waste biomass. TPC is considered to be applied as an additional fuel for a metallurgical furnace as an example of effective energy management in metallurgical industry. In detail, the technology contains waste heat recovery unit installed on the furnace smoke stack as the heat source for the pyrolysis/torrefaction reactor. The analysis was carried out for a pusher furnace, fed optionally with either natural gas or coke gas. Share of this gaseous/liquid TPC fuel from waste in the total fuel mixture fed to the furnace was varied from 5 to 15% by volume. Practical usefulness of TPC fuel was tested on a specially constructed test stand. Financial analysis in energy consumption and economy of using the obtained TPC fuel for co-combustion with coke gas in the metallurgical pusher furnace was carried out on the basis of data from a steel sheet roller combined with the pusher furnace located in one of large steel works. It was shown that the use of this TPC fuel derived from thermal treatment of waste biomass and other organic substances can be considered an effective method of reducing production costs in the analyzed steel company and can lead to increase in the attractiveness of their products and thus strengthen their competitiveness on the global market. Graphic abstract

Section: Innovative Strategies and Technologiesmentioning

confidence: 99%

Integration of waste biomass thermal processing technology with a metallurgical furnace to improve its efficiency and economic benefit

Zajemska

Clean Techn Environ Policy

et al. 2021

“…Sintering technology is a complex thermo-chemical and energy-intensive process, and the price of its raw material-iron ore-has always been high. As a result, how to control costs and improve profits are the core issues that can affect the survival of sinter plant enterprises [1,2]. Research on sinter composition optimization is an extremely important field of sinter mineralogy, and the quality of ingredients affects the final sinter quality.…”

Section: Introductionmentioning

confidence: 99%

“…In the SCORN model, we employ the Conv layer to generate more features from the previous layer (e.g., the first Conv layer has the filter size of [1,1], number of filters: 12, stride size of [1,1] and zero padding. Hence, the final output size is 1 × 12).…”

mentioning

confidence: 99%

SCORN: Sinter Composition Optimization with Regressive Convolutional Neural Network

Guo

Zhang

2022

Solids

Sinter composition optimization is an important process of iron and steel companies. To increase companies’ profits, they often rely on innovative technology or the workers’ operating experience to improve final productions. However, the former is costly because of patents, and the latter is error-prone. In addition, traditional linear programming optimization methods of sinter compositions are inefficient in the face of large-scale problems and complex nonlinear problems. In this paper, we are the first to propose a regressive convolutional neural network (RCNN) approach for the sinter composition optimization (SCORN). Our SCORN is a single input and multiple outputs regression model. Sinter plant production is used as the input of the SCORN model, and the outputs are the optimized sintering compositions. The SCORN model can predict the optimal sintering compositions to reduce the input of raw materials consumption to save costs and increase profits. By constructing a new neural network structure, the RCNN model is trained to increase its feature extraction capability for sintering production. The SCORN model has a better performance compared with several regressive approaches. The practical application of this predictive model can not only formulate corresponding production plans without feeding materials but also give better input parameters of sintered raw materials during the sintering process.

“…The sinter waste heat resource accounts for about 8% of the total waste heat resources of iron and steel enterprises in China, which is one of the resources producing large amounts of waste heat with the greatest development potential [1][2][3][4]. Sinter annular coolers and vertical coolers are two main types of equipment for sinter waste heat recovery (SWHR), and annular coolers have been widely used in the production of SWHR.…”

Section: Introductionmentioning

confidence: 99%

Energy and Exergy Efficiency Analysis of Fluid Flow and Heat Transfer in Sinter Vertical Cooler

et al. 2021

In order to fully understand the energy and exergy transfer processes in sinter vertical coolers, a simulation model of the fluid flow and heat transfer in a vertical cooler was established, and energy and exergy efficiency analyses of the gas–solid heat transfer in a vertical cooler were conducted in detail. Based on the calculation method of the whole working condition, the suitable operational parameters of the vertical cooler were obtained by setting the net exergy efficiency in the vertical cooler as the indicator function. The results show that both the quantity of sinter waste heat recovery (SWHR) and energy efficiency increased as the air flow rate (AFR) increased, and they decreased as the air inlet temperature (AIT) increased. The increase in the sinter inlet temperature (SIT) resulted in an increase in the quantity of SWHR and a decrease in energy efficiency. The air net exergy had the maximum value as the AFR increased, and it only increased monotonically as the SIT and AIT increased. The net exergy efficiency reached the maximum value as the AFR and AIT increased, and the increase in the SIT only resulted in a decrease in the net exergy efficiency. When the sinter annual production of a 360 m2 sintering machine was taken as the processing capacity of the vertical cooler, the suitable operational parameters of the vertical cooler were 190 kg/s for the AFR, and 353 K for the AIT.