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A bout esfahan mobarak steel slag

Azarnafis Company Slag Processing

Steel slag is a side product created during steel production process which is produced as furnace slag phase.

There are 3 types of slag in the industry:

1- High furnace slag

2- Arc electricity slag

3- Oxygen furnace slag

Slag is a complex metallic or non-metallic composite that because of cooking and heating at 1600°C they are enormously strong and durable.

During melting the iron stone, furnace slag, consisted of calcium oxide and dolomite because of more density rather than the materials with impurities stay above and act as protective isolation against oxygen and then after bringing out the rough pure steel slag, remained material are ready to cool and use as slag.

Slag types:

Artificial slag is produced during different steps. From steel and iron production to slag, all of them consists different carbon content levels.

Slag cooling process methods:

1- slowly exposed to air (air-cooled slag)

2- rapidly cooling molten slag with water jet

In the first method, because of the slow speed of cooling, slag forms with larger crystals in size and this slag is more resistant and stronger rather than fast method. Its main usage is in construction such as railway ballast, hot mix asphalt and concrete.

Physical and chemical properties

Its color is dark gray. It has higher durability and strength rather than granular stone and they are rectangular and sharp in shape which leads to more interaction and more friction between grains and makes it suitable material for foundation constructions.

In terms of chemical properties, slag is very similar to Portland cement which consists of lime, sillies and alumina.

Azarnafis slag properties

Our company processes slag in the site in Mobarakeh Steel Complex by cooling method. The slag products separates from melting iron; at this point it transfers to the special slag ponds, then it cools slowly due to exposing to air which causes large crystal formation leading to best strength and highest durability. At this stage, cold or semi-cold slag is transferred to the depot. To be sure for reaching the stability of slag, material should be exposing to the normal weather condition for at least one year. This period could be longer than a year to 5 or more in some places such as Isfahan or Mobarakeh with dry weather. Our company use steel slag which has remained and protected exposing to free air for about 15 years to be sure for the high quality of our products. Finally, produced material is ready to use in the industrial cycles.

Slag processing

It is necessary to segregate impurities (lime, ashes, construction rubbish, soil etc.) from steel slag in the depot site and slag is ready for final proffer. Then it conveys to the considered line for processing and production lines. In addition, crushing and aggregation cycles are carried out beside segregation of iron fragments. Free iron existence among the main material could have further negative effects such as problems which are considered by customers from road constructions to cement and concrete, so that Azarnafis company carry out steel segregation process in several steps by special magnet facilities which are designed and constructed specifically for steel slag production.

Slag products

Slag products are mainly artificial grains in various ranges. Its categories are different up to their size. Moreover, this material have its own feature depends on their crushing properties, material qualities and their aggregation.

Production flow of the blast furnace slag

author: A.Boruni - Date: 4/12/2020