Specific weight of blast-furnace slag in 1 m3, volumetric weight and density
Slags are artificial silicate materials formed during metallurgical processes. A slag melt may contain compounds of silicon, iron, calcium, manganese, sulfur and other elements. After cooling, the melt can turn into a dense stone-like mass or a porous material similar to pumice. The final structure depends on the oxide composition and cooling rate.
In appearance, slags resemble natural rocks: they may be green, yellow, gray, pink, white, black or mixed in color. By structure, this industrial raw material can be dense or porous, heavy or lightweight.
Slag density can vary from about 800 to 3200 kg/m³. The true density of slag substance is close to that of natural stone materials and is often in the range of 2.5 - 3.6 g/cm³. During metallurgical processing, slag must be lighter than molten metal so that it rises to the surface of the melting bath and separates from the metal.
| Blast-furnace slag type | Weight, t/m³ | Weight, kg/m³ | Density, g/cm³ |
| Slag crushed stone | 1.05 - 1.6 | 1050 - 1600 | 1.05 - 1.6 |
| Lump slag | 2.1 - 2.8 | 2100 - 2800 | 2.1 - 2.8 |
| Slag concrete | 2.0 - 2.4 | 2000 - 2400 | 2.0 - 2.4 |
Types of slag and formation process
The construction industry actively uses industrial raw materials of metallurgical origin. Such material has already been exposed to high temperatures, has a formed mineral structure and can be used as an aggregate or component of building materials. Metallurgical production by-products are commonly divided into:
- ferrous metallurgy waste;
- non-ferrous metallurgy waste;
- steelmaking slags.
Blast-furnace slag as construction raw material
One of the most common industrial materials is blast-furnace slag from ferrous metallurgy. It forms during pig iron smelting in a blast furnace and contains components of gangue, fluxes and fuel ash. The quantity and properties of slag depend on raw material composition, sulfur content, lime amount and the technological process.
Blast-furnace slag is used to produce slag crushed stone, granulated slag, cement additives, slag concrete and other building materials. The average weight of lump material is often about 2500 kg/m³, but depending on condition and structure it may range from 2100 to 2800 kg/m³.
For practical calculations, it is convenient to use ready values for the weight of 1 m³ of blast-furnace slag according to its condition: crushed slag, lump slag or slag concrete. These approximate values are shown in the table above.
Frequently Asked Questions
Can the density of blast-furnace slag be used for precise calculations?
The density and weight values for blast-furnace slag in this article are reference values. They are suitable for preliminary estimates, but design, construction, production and other critical calculations should be checked against standards, material datasheets or measurement results.
Why can the actual weight of blast-furnace slag differ from the table?
The actual weight of blast-furnace slag depends on composition, moisture, temperature, porosity, fraction size, material grade and measurement conditions. Because of this, real values may differ from the average table data.
How do you calculate the mass of blast-furnace slag from density?
For an approximate calculation, use the formula: mass = density × volume. If the density of blast-furnace slag is given in kg/m³ and the volume is in m³, the result will be in kilograms.