Binder for Iron-containing Dust and Sludge Briquetting in Steel Mills 

Iron-containing Dust Briquetting Binder

Iron-containing dust primarily consists of baghouse dust collected by the dust removal systems during iron and steel smelting processes. Its main components are iron and carbon, along with some harmful impurities such as zinc, lead, potassium, sodium oxides, etc. For a long time, most of this dust has been recycled by returning it to sintering or briquetting processes before being reintroduced into blast furnaces or converters for smelting. However, as harmful elements like zinc, lead, potassium, and sodium continuously accumulate in the blast furnace process, and the proportion of scrap galvanized steel used in steelmaking gradually increases, the zinc content in the dust and sludge has also been rising. At the same time, excessive zinc content in the furnace charge, due to its low boiling point, volatilizes inside the blast furnace and accumulates in the upper shaft, gradually forming scaffolds that affect smooth furnace operation and shorten the blast furnace's lifespan. Therefore, it is difficult to directly recycle all zinc- and iron-containing dust and sludge with high levels of elements like zinc, lead, potassium, and sodium back into production units in integrated steel enterprises, as this approach has limitations. Currently, steel mills primarily dispose of iron-containing dust and sludge with high levels of harmful elements, especially zinc-containing iron dust and sludge, through social utilization or landfilling. These methods involve high logistics costs, multiple steps, and are prone to causing environmental pollution. Hence, finding reasonable and effective treatment technologies to achieve comprehensive resource utilization and recycling is a core issue in solid waste management for the iron and steel metallurgical industry.

Currently, there are several main types of binders for briquetting.
The first type: Using magnesium chloride, water glass, etc., for briquetting. Although the unit price is cheap, the required dosage is high, and the briquette formation rate is low. The cost is relatively high, and the chlorine content can corrode the steel mill's combustion furnaces. Generally, steel mills do not allow the use of magnesium chloride and water glass.
The second type: Since dust removal ash contains calcium oxide, many manufacturers use ammonia as a raw material to counteract calcium oxide. However, this material has a pungent odor and is also rejected by steel mills.
The third type: Composite binders. This is currently an acceptable and relatively environmentally friendly method in the market for steel mills. However, the effectiveness varies among different manufacturers. It is necessary to communicate specifically with binder manufacturers, conduct tests, and then select the appropriate one.

The iron-containing dust and sludge binder developed by our company is a powdered, composite, environmentally friendly binder. We can provide technical support free of charge and send raw materials for formulating the binder.