What is slag

Slag is an industrial waste that is excluded in the iron making process. In the blast furnace iron making process, in addition to iron ore and fuel, in order to reduce the smelting temperature, an appropriate amount of limestone should be added as a co-solvent, which is obtained by decomposing them in the blast furnace. Calcium oxide, magnesium oxide, waste ore in iron ore, and ash in coke are dissolved together to form a melt with silicate and aluminosilicate as the main components floating on the surface of molten iron, which is regularly discharged from the slag discharge port , which is quenched by air or water to form granular particles, which is granulated blast furnace slag, referred to as "slag". Slag is a material with "latent hydraulic", that is, it is basically non-hydraulic when it exists alone, but under the action of some activators (lime, clinker powder, alkalis, gypsum, etc.), it exhibits hydraulic performance.

Use of slag

1. As a raw material to produce slag Portland cement, granulated blast furnace slag is mixed with Portland cement clinker, and then 3~5% gypsum is added to mix and grind to make slag Portland cement, which can be better used in water engineering , harbour and underground works, etc.

2. It can be used to produce slag bricks and wet-rolled slag concrete products.

3. Put the water slag and activator (cement, lime and gypsum) on the wheel mill and grind it with water to make mortar, and then mix it with coarse aggregate to form wet-milled slag concrete.

4. It can be prepared with slag and gravel concrete, which has a wide range of applications in road engineering and railway engineering.

5. Application of expanded slag and expanded beads Expanded slag is mainly used as lightweight aggregate to make lightweight concrete.

Slag milling process

Analysis of main blast furnace slag raw materials (%)

Slag grinding mill selection scheme

1. Drying

According to the moisture content of the raw materials and the moisture content requirements of the finished product, the slag uses a dryer to remove moisture for materials with high moisture content. Materials with low moisture content can be treated with hot air through a hot blast furnace to the mill. Through the process of grinding and drying, the equipment investment cost and operating energy consumption cost of the dryer can be reduced.

2. Grinding

The dried slag small pieces of material are sent to the raw material hopper by the elevator, and then sent to the grinding chamber of the mill evenly and quantitatively by the conveying feeder for grinding.

3. Classifying

The pulverized materials are classified by the classification system, and the unqualified powders are classified by the classifier and then returned to the main engine for re-grinding.

4. Collection

The powder that meets the fineness enters the dust collector through the pipeline with the airflow for separation and collection, and the collected finished powder is sent to the finished product silo by the conveying device through the discharge port, and then loaded into the powder tanker uniformly.

Analysis of various mills

Vertical Mill:

The equipment is large-scale and the output is high, which can meet the large-scale production. The vertical mill has high stability. Disadvantage, equipment investment cost is high.

Classic case of slag milling

Model: 1set of HLM21

Processing raw material: slag

Finished product fineness: 200 mesh D90

Equipment output: 15-20 t/h

The failure rate of Hongcheng slag grinder is very low, the operation is very stable, the noise is low, the dust collection efficiency is relatively high, the operation site is very environmentally friendly, and we are even more overjoyed that the output value of the grinder greatly exceeds the expected value, Created considerable benefits for our business. The after-sales service team is very attentive and enthusiastic. They return to visit the equipment regularly to check the operation status of the equipment, which has solved a lot of practical difficulties for us and set up multiple guarantees for the normal production of the equipment.