With the continuous development of the power industry, more and more metal slag is generated in power plants. These slag is usually considered waste. However, these waste contains a large amount of metal resources. If they can be recycled, not only can they reduce environmental pollution, but also bring huge economic benefits to society. This article will introduce the operational steps for recycling metal slag from power plants.
1、 Classification of metal slag
Firstly, it is necessary to classify metal slag. According to its composition, metal slag can be divided into iron slag, steel slag, copper slag, aluminum slag, etc. The composition of each type of slag is different, and the methods of recycling are also different.
2、 Treatment of metal slag
The purpose of treating metal slag is to separate useful metals from it. Common treatment methods include magnetic separation, flotation, gravity separation, heat treatment, etc.
1. Magnetic separation method
Magnetic separation method is a method of separating metals in slag using magnetic substances. Firstly, the slag is crushed and screened, and then magnetic separation is carried out on the slag through a magnetic separator to separate magnetic metals such as iron and nickel.
2. Flotation method
Flotation method is a method of separation that utilizes the difference in specific gravity of metals in slag. Firstly, the slag is crushed and screened, and then immersed in water containing flotation agents. The metals in the slag are separated by bubbles.
3. Reselection method
Gravity separation method is a method of separation by using the density difference of metal in slag. Firstly, the slag is subjected to crushing and screening treatment, and then it is re selected by a gravity separator to separate heavy metals such as copper and aluminum from it.
4. Heat treatment method
The heat treatment method is a method of separation that utilizes the difference in melting points of metals in slag. Firstly, the slag is crushed and screened, then heated to a certain temperature to melt the metal inside, and then separated through cooling.
3、 Recycling and utilization of metal slag
After the above treatment, the useful metals in the metal slag have been separated, and the next step is to recycle them. There are various methods of recycling, such as making building materials, producing cement, and making ferroalloys.
1. Made of building materials
Metal slag can be made into various building materials, such as cement, bricks, road materials, etc. These materials not only have good physical properties, but also can reduce environmental pollution.
2. Production of cement
Silicon, aluminum and other elements in metal slag are important raw materials for cement production. By mixing these elements in metal slag with limestone, gypsum, etc., high-quality cement can be produced.
3. Making ferroalloys
Metal slag contains a large amount of metals such as iron and nickel, and can be made into ferroalloys through smelting, which is an important metallurgical raw material.
In short, recycling metal slag from power plants is an important task. By classifying, treating, and recycling metal slag, it can not only reduce environmental pollution but also bring huge economic benefits to society.