Operation and simulation of pressurized shaft furnace for direct reduction.

Coke constitutes the major portion of ironmaking cost and its production causes the severe environmental concerns. So lower energy consumption, lower CO2 emission and waste recycling are driving the iron and steel industry to develop alternative, or coke-free, ironmaking process. Midrex and HYL Energiron are the leading technologies in shaft furnace direct reduction, and they account for about 76% of worldwide production. They are the most competitive ways to obtain high quality direct reduced iron (DRI) for steelmaking. Therefore, in the present paper, some detailed information about these two processes are given. Much attention has been paid on process scheme, the feedstock, DRI product, heat recovery, reforming gas, hot discharge and transportation, and by-product emission. Its very important for direct reduction development in both natural gas-rich counties and natural gas-poor counties.

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Hydrogen Ironmaking: How It Works

Metals ◽

10.3390/met10070922 ◽

2020 ◽

Vol 10 (7) ◽

pp. 922 ◽

Cited By ~ 3

Author(s):

Fabrice Patisson ◽

Olivier Mirgaux

Keyword(s):

Iron Ore ◽

Shaft Furnace ◽

Direct Reduction ◽

Water Electrolysis ◽

Current Standard ◽

Ore Pellets ◽

Production Of Hydrogen ◽

Produce Steel ◽

And Performance ◽

Direct Reduction Of Iron

A new route for making steel from iron ore based on the use of hydrogen to reduce iron oxides is presented, detailed and analyzed. The main advantage of this steelmaking route is the dramatic reduction (90% off) in CO2 emissions compared to those of the current standard blast-furnace route. The first process of the route is the production of hydrogen by water electrolysis using CO2-lean electricity. The challenge is to achieve massive production of H2 in acceptable economic conditions. The second process is the direct reduction of iron ore in a shaft furnace operated with hydrogen only. The third process is the melting of the carbon-free direct reduced iron in an electric arc furnace to produce steel. From mathematical modeling of the direct reduction furnace, we show that complete metallization can be achieved in a reactor smaller than the current shaft furnaces that use syngas made from natural gas. The reduction processes at the scale of the ore pellets are described and modeled using a specific structural kinetic pellet model. Finally, the differences between the reduction by hydrogen and by carbon monoxide are discussed, from the grain scale to the reactor scale. Regarding the kinetics, reduction with hydrogen is definitely faster. Several research and development and innovation projects have very recently been launched that should confirm the viability and performance of this breakthrough and environmentally friendly ironmaking process.

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Effects of B-Mg Additive on Metallurgical Properties of Oxidized Pellets

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.284-286.1232 ◽

2011 ◽

Vol 284-286 ◽

pp. 1232-1236

Author(s):

Zhao Cai Wang ◽

Man Sheng Chu ◽

Shi Qiang Chen ◽

Zheng Gen Liu ◽

Jue Tang ◽

...

Keyword(s):

High Efficiency ◽

Shaft Furnace ◽

Direct Reduction ◽

Strength Reduction ◽

Metallurgical Properties ◽

Remarkable Improvement ◽

Oxidized Pellets ◽

Reduction Swelling ◽

Roasting Temperature ◽

Addition Amount

The metallurgical properties of oxidized pellets are of great importance to achieve high efficiency and smooth running of blast furnace and gas-based direct reduction shaft furnace. In this study, the new method of adding B-Mg compound additive has been put forth to improve metallurgical properties of pellets. The effects of adding B-Mg additive on the strength of green balls, cold compressive strength, reduction swelling, and the strength after reduction and cooling of oxidized pellets are investigated through the experiments and microstructure analysis. The results revealed that, the B-Mg additive has not-so-remarkable effects on the properties of green balls. The rational addition amount of B-Mg additive is 0.6 %, and B-Mg additive make it feasible to reduce roasting temperature of the pellets. High temperature properties show remarkable improvement with the increase of B-Mg additive amount, the RSI decrease from 14.7% to 7.17%, and the strength of pellets after reduction and cooling increase from 162.5 N to 650.8 N when the addition amount increases from 0 to 0.6%.

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Fundamental Study on Application of Gas-Based Shaft Furnace Direct Reduction Process to High Efficiency and Clean Utilization of Paigeite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.233-235.753 ◽

2011 ◽

Vol 233-235 ◽

pp. 753-758

Author(s):

Zhao Cai Wang ◽

Man Sheng Chu ◽

Zhuang Nian Li ◽

Jue Tang ◽

Qing Jie Zhao ◽

...

Keyword(s):

Electric Furnace ◽

Shaft Furnace ◽

Direct Reduction ◽

Reduction Process ◽

Technical Problems ◽

Direct Reduction Process ◽

Comprehensive Utilization ◽

Iron Concentrate ◽

New Process ◽

Reduction Swelling

The paigeite resources are abundant in China, but most of them are difficult to be utilized efficiently because of the current technical problems on industrial practice. It is necessary to perfected and innovated for comprehensive utilization of paigeite. The new process of gas-based shaft furnace direct reduction-electric furnace smelting separation provides a new way to efficient and clean comprehensive utilization of paigeite resources. In this paper, the pellets are prepared from boron-bearing iron concentrate. The mechanisms of roasting, the rules of reduction, and the properties of reduction swelling are also investigated. And then the pellets after reduction are smelted and separated in electric furnace to study the properties of products and analyze the feasibility and superiority of new technique. The results showed that boron-bearing iron concentrate is a kind of good raw material for pelletizing process. The properties of boron-bearing pellets after roasting for 20 min at 1200°C could meet to the requirements of gas-based shaft furnace direct reduction process, which exhibited fast reaction rate, good reduction swelling properties and high compressive strength both before and after reduction. With the new process, the efficient separation of boron and iron can be realized. The high boron grade and high activity of boron-rich slag obtained from new process can be used directly in boric acid manufacture. The new process shows excellent tech-economy feasibility to achieve efficiency and clean comprehensive utilization of paigeite resources.

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96/04854 A direct reduction process by shaft furnace with gasification of coal and enriched oxygen

Fuel and Energy Abstracts ◽

10.1016/0140-6701(96)89579-8 ◽

1996 ◽

Vol 37 (5) ◽

pp. 343

Keyword(s):

Shaft Furnace ◽

Direct Reduction ◽

Reduction Process ◽

Direct Reduction Process

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Effects of Preheating Temperature and Time of Hongge Vanadium Titanomagnetite Pellet on Its Gas-Based Direct Reduction Behavior with Simulated Shaft Furnace Gases

ISIJ International ◽

10.2355/isijinternational.isijint-2017-486 ◽

2018 ◽

Vol 58 (4) ◽

pp. 594-603 ◽

Cited By ~ 2

Author(s):

Wei Li ◽

Nan Wang ◽

Guiqin Fu ◽

Mansheng Chu ◽

Miaoyong Zhu

Keyword(s):

Shaft Furnace ◽

Direct Reduction ◽

Reduction Behavior ◽

Preheating Temperature ◽

Furnace Gases

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Model Study on Burden Distribution in COREX Melter Gasifier

Processes ◽

10.3390/pr7120892 ◽

2019 ◽

Vol 7 (12) ◽

pp. 892

Author(s):

Haifeng Li ◽

Zongshu Zou ◽

Zhiguo Luo ◽

Lei Shao ◽

Wenhui Liu

Keyword(s):

Mathematical Model ◽

Growth Mechanism ◽

Gas Flow ◽

Layer Structure ◽

Shaft Furnace ◽

Direct Reduction ◽

Stable Operation ◽

Burden Distribution ◽

Charging System ◽

Physical Experiments

COREX is one of the commercialized smelting reduction ironmaking processes. It mainly includes two reactors, i.e., a (reduction) shaft furnace (SF) and a melter gasifier (MG). In comparison with the conventional blast furnace (BF), the COREX MG is not only equipped with a more complicated top charging system consisting of one gimbal distributor for coal and eight flap distributors for direct reduction iron (DRI), but also the growth mechanism of its burden pile is in a developing phase, rather than that in a fully-developed phase in a BF. Since the distribution of charged burden plays a crucial role in determining the gas flow and thus in achieving a stable operation, it is of considerable importance to investigate the burden distribution influenced by the charging system of COREX MG. In the present work, a mathematical model is developed for predicting the burden distribution in terms of burden layer structure and radial ore/coal ratio within the COREX MG. Based on the burden pile width measured in the previous physical experiments at different ring radii on a horizontal flat surface, a new growth mechanism of burden pile is proposed. The validity of the model is demonstrated by comparing the simulated burden layer structure with the corresponding results obtained by physical experiments. Furthermore, the usefulness of the mathematical model is illustrated by performing a set of simulation cases under various charging matrixes. It is hoped that the model can be used as a what-if tool in practice for the COREX operator to gain a better understanding of burden distribution in the COREX MG.

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