In today’s industrial world, the production of metals such as iron and steel plays a vital role in the development of societies. However, the production process of these valuable metals is not without side waste. Slag , a byproduct of the iron and steel production process, is one of these wastes that was discarded as worthless waste in the past. But fortunately, human science and knowledge have found ways to turn these wastes into valuable treasures.

Slag is a non-metallic material with a complex combination of silicates, oxides and metals. With its unique properties, this material can be used in various industries. Among the salient features of slag, the following can be mentioned:

• High resistance: slag is resistant to corrosion, erosion and freezing and has a long life.
• Adjustability: The properties of slag can be adjusted and its composition can be changed according to needs.
• Environmentally friendly: slag is a non-toxic and sustainable material that causes less harm to the environment than some raw materials.

Due to these characteristics, slag has found many applications in various industries. Among the most important uses of this material, the following can be mentioned:

1. Cement industry: slag, as a substitute for part of limestone in cement production, increases its strength and durability. This significantly reduces the cost of cement production while providing a higher quality product.

2. Refractory industry: slag is used in the production of refractory bricks. Due to their high heat resistance, these bricks are used in industrial furnaces and other high temperature facilities.

3. Road construction industry: slag is used as stone material in road infrastructure. This material increases the resistance and stability of roads and prevents their erosion and damage.

4. Other uses: In addition to the mentioned cases, slag is also used in various industries such as water treatment, agriculture, concrete making, etc.

Using slag has significant benefits, including:

• Cost reduction: Replacing expensive raw materials with slag significantly reduces production costs.
• Increasing stability: slag increases the strength and lifespan of structures.
• Environmental protection: By recycling slag, the accumulation of industrial waste and the destruction of the environment are prevented.
• Creating employment: recycling and using slag creates new job opportunities in various industries.

According to the mentioned advantages, slag plays a key role in promoting sustainability and preserving land resources and is known as an important step towards green production and environmental protection. For this reason, in many countries of the world, extensive efforts are being made to increase the use of this valuable substance.

In Iran, fortunately, great steps have been taken in the direction of using slag. So that, at present, this material is used in the production of cement, concrete, sand, etc. By raising awareness and supporting this nascent industry, we can see significant progress in the field of recycling and using slag in Iran, and in this way, take an important step towards preserving natural resources and sustainable development.