What is foamy slag?

Abstract. Slag foaming is part of steelmaking process and could bring several benefits: it helps to save energy, improves productivity, enhances the refractory service life, decreases noise pollution and protects the bath from nitrogen incorporation.

What is foamy slag practice?

Slag foaming is one of the main practices to be induced and controlled during the electric arc (EAF) furnace operation [1], [9], [10], [11]. This procedure has an important impact on the thermal efficiency, tapping time (reducing the cold charge melting) and refractory lining/electrodes consumption of the EAF.

What is foamed slag used for?

Slag foaming has been mainly used in electric arc furnaces (EAF) in order to protect the refractory materials from the high energy intensity (radiation) generated by electrodes, decrease the noise level, improve productivity and the energy efficiency of this equipment.

What is blast furnace slag used for?

Granulated blast furnace slag has been used as a raw material for cement production and as an aggregate and insulating material. and granulated slag have also been used as sand blasting shot materials.

In what form is hydrogen dissolved in liquid steel?

Hydrogen solubility in liquid steel is considerably higher than in solid steel. As a result, diatomic hydrogen is formed during cooling and solidification of the steel. The hydrogen gas creates pressure sites in the steel matrix, which may give rise to failure or surface defects.

Is blast furnace slag a pozzolan?

The use of pozzolan in cement provides economic advantages and improves the physico-mechanical properties of cement. Fly ash and blast furnace slag are widely used in cement as pozzolanic materials. It was concluded that obsidian was equivalent to blast furnace slag as a pozzolan.

Do steel plants generate oxygen?

Steel plants enhanced manufacturing and supplies of medical oxygen by reducing the production of nitrogen and argon gases.

What is silicon killed steel?

When steel has been fully deoxidized before casting and no gas was evolved during solidification, the resultant steel is known as killed steel. This steel is characterized by a high degree of chemical homogeneity.

Is slag a carcinogen?

Carcinogenicity: Slag is not listed as a carcinogen by IARC or NTP; however, slag contains trace amounts of crystalline silica and hexavalent chromium which are classified by IARC and NTP as known human carcinogens.

Why is slag bad?

When SSRS compares with ground granulated blast furnace slag (GGBFS) from iron making, steel slag contains toxic ingredients such as nickel, cadmium, chromium and strontium. These compounds could be harmful not only for environment but also for human health [9,10].

Why is slag used in the EAF process?

Slag foam is beneficial for the EAF steelmaking process in terms of the large surface area formed and the protection provided against the direct contact of the melt with the atmosphere. The slag foaming is a technique which is both useful as well as economical.

How is slag foaming used in the arc furnace?

What is the driving force for the foaming of slag?

Driving force for slag foaming is a pneumatic energy provided by CO generation during the process of the melting-refining in the EAF. In the slag foaming process, carbon is injected into the slag, reacts with iron oxide (FeO) in the slag to produce carbon monoxide (CO), which foams the slag. The reaction is given by C (injected) + (FeO) = Fe + CO.

How does oxygen help in foaming of slag?

In step 3, oxygen is injected into the slag, to cause oxidation of the carbon present in the slag. In this step, carbon and oxygen can also be injected simultaneously, allowing better generation of CO and better foaming. There is normally a dense layer of slag beneath the foam.

What is foamy slag? Abstract. Slag foaming is part of steelmaking process and could bring several benefits: it helps to save energy, improves productivity, enhances the refractory service life, decreases noise pollution and protects the bath from nitrogen incorporation. What is foamy slag practice? Slag foaming is one of the main practices to be induced…