Effect of Processing Parameters on the Swelling Behaviour of Cement-bonded Briquettes

The effects of firing and reduction conditions on swelling and iron whisker growth were investigated. The iron oxide compacts sintered in air were reduced in the tubular high temperature reactor by carbon monoxide or hydrogen. The experimental results showed that catastrophic swelling was suppresed by increasing the firing temperature or the firing time at moderate firing temperatures. The severest swelling happened in the reduction temperature of 900-1 000°C with carbon monoxide. No catastrophic swelling was observed when hydrogen was used as the reducing gas. The SEM micrographs showed that catastrophic swelling was caused by a large amount of long whiskers formed during the reduction. The number of nucleation sites of whisker growth was limited when the firing temperature was increased above 1 000°C, which also suppressed catastrophic swelling. On the basis of exprimental data and SEM results, a conceptual diagram was formulated to describe the effects of firing and reduction conditions on iron whisker growth and swelling.

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“…[23][24][25] The reduction rate is fast when H2 is present in the reducing gas, and metal bond resists against swelling.…”

Section: Reduction Of Iron Oxide With Hydrogenmentioning

confidence: 99%

“…Singh and Bjorkman [23][24][25] studied the effect of reduction conditions on the swelling behavior of cement-bonded briquettes. It was observed that, under certain conditions, the briquettes containing fines generated from pellets during handling show a tendency to swell catastrophically when reduced at 900-1 000°C using CO.…”

Section: Introductionmentioning

confidence: 99%

Effects of Firing and Reduction Conditions on Swelling and Iron Whisker Formation during the Reduction of Iron Oxide Compact

Wang

Sohn

2011

ISIJ International

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“…Coke is used as the primary reducing agent in two blast furnaces. Coke oven gas, composed mainly of H 2 , CH 4 and CO with heating value of 16-18 MJ/Nm 3 , is utilized chiefly in the steel plant processes. Sulfur and benzene are sold as by-products to other industries.…”

Section: System Boundariesmentioning

confidence: 99%

“…Sintering, which is a unit process to agglomerate iron ore fines in high temperature, has been traditionally used to refine many of the solid residues produced inside the system boundaries [2,3]. In steel plants that do not include a sintering plant, solid iron-bearing residues can be recycled back to the blast furnace via a briquetting plant where cement-bonded briquettes are produced [4]. Another option for treating dust and scales is to use alternative recycling technologies, e.g., Oxycup or rotary hearth furnace (RHF) [5].…”

Section: Introductionmentioning

confidence: 99%

Recycling of Coking Plant Residues in a Finnish Steelworks—Laboratory Study and Replacement Ratio Calculation

Suopajärvi

Salo

Paananen³

et al. 2013

Resources

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Abstract:Material efficiency is one of the most effective methods for achieving more sustainable operations in iron and steelmaking. Sintering and briquetting processes are commonly used in integrated steel plants to recycle carbon-and iron-containing residues back to blast furnace. In the Ruukki steelworks in Finland, a surplus of solid coking plant by-products is produced, none of which are presently utilized within the steelworks. In this paper, a novel concept for recycling solid coking plant by-products to a blast furnace via liquid-solid injection is evaluated. According to the conducted laboratory study, all the solid by-products could be utilized via liquid-solid mixture injection. By pulverizing the coke gravel and coke sand and mixing it with extra heavy bottom oil, the annual coke requirement of a blast furnace could be decreased by almost 9% with constant oil injection and could reduce annual oil requirements by almost 39% with constant coke rate. Evaluation of direct and indirect environmental impacts reveals that there would be more positive than negative impacts when recycling solid coking plant by-products inside steel plant boundaries.

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“…4) Maneesh et al 5,6) studied the effect of reduction conditions on the swelling behavior of cement bonded briquettes. They found that the swelling of briquettes increases with the increase in average particle size of the raw material also the briquettes containing a larger amount of slag-forming oxides, CaO, SiO 2 , MgO and Al 2 O 3 may swell more.…”

Section: Introductionmentioning

confidence: 99%

Reduction Kinetics and Catastrophic Swelling of MnO2-doped Fe2O3 Compacts with CO at 1073-1373 K

El-Geassy¹,

Nasr

Omar³

et al. 2007

ISIJ Int.

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Effect of Processing Parameters on the Swelling Behaviour of Cement-bonded Briquettes

Cited by 24 publications

References 1 publication

Effects of Firing and Reduction Conditions on Swelling and Iron Whisker Formation during the Reduction of Iron Oxide Compact

Effects of Firing and Reduction Conditions on Swelling and Iron Whisker Formation during the Reduction of Iron Oxide Compact

Recycling of Coking Plant Residues in a Finnish Steelworks—Laboratory Study and Replacement Ratio Calculation

Reduction Kinetics and Catastrophic Swelling of MnO2-doped Fe2O3 Compacts with CO at 1073-1373 K

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