Products steasint® Production Bottom ash is produced from the non-combustible, mineral coal components in modern coal-fired power plants, which are sintered and cooled down in a water quench. In the dry bottom boilers of these power plants, pulverized coal is burnt at temperatures around 1200°C (2200°F). At these temperatures, the carbon is combusted, but the melting point of the non-combustible, mineral components is not exceeded. The powdery ash particles are carried along with the flue gas stream, and the biggest portion is extracted as fly ash through electrostatic precipitators. Some of the particles, however, stick to each other on their way through the boiler, forming agglomerations by sintering. Due to their higher weight, these agglomerates can no longer be carried by the flue gas stream. They fall into a water quench below the boiler. The resulting porous material is the steasint bottom ash. By means of pre-storage, an average material humidity of 20 to 25 Wt.% can be achieved. In power plants with dry bottom boilers, up to 10 Wt.% of the ash produced is bottom ash. Properties Due to its porous structure, steasint has material characteristics similar to those of natural and artificial lightweight aggregates. Macroscopically, steasint is a humid, fine and lightweight sand with a gray to brown color and a compact, slaggy particle shape. steasint is produced with a particle size distribution of 95 Wt.% smaller than 10 mm and a large portion (about 50 Wt.%) of fine particles smaller than 1 mm. Most of the particles larger than 10 mm are only loosely sintered agglomerates with a low strength. steasint is normally used in the original production quality. However, on demand it can also be sieved to achieve certain particle sizes. Particle size distribution of steasint Particle size 0 - 8 mm sieved 0 - 4 mm Bulk density 0.6 - 0.8 g/cm³ Raw particle density 1.6 - 1.7 g/cm³ Loss on ignition <5.0 Wt.% Average material characteristics steasint is very environment-friendly. Due to its production process, steasint is a washed material. Therefore the amount of soluble components in steasint bottom ash is comparable to the values normally measured in excavated material. Applications In consideration of the applicable regulations, steasint bottom ash can be used just like a natural mineral material. Due to its material properties, steasint is suitable for a wide variety of qualified applications. Currently steasint is mostly used in its unbound form in the area of earthwork and road construction and as an additive for the production of bricks. Approved by the German Instutite for Building Technology (Deutsches Institut für Bautechnik, Berlin), steasint is also used as an additional or – mainly for mortars – exclusive lightweight aggregates. Besides these main application areas, steasint is also suitable for use as a substratum component for greenroof construction and for soil enhancement in agriculture. Mortar and concrete Lightweight aggregates Earthwork and road construction Earth material Gardening andagriculture Soil enhancement Greenroofs Substratumcomponent Brick production Additive forleanness/porosity Sand-lime bricksSpecial applications Additive isteasint® is a registered trademark of STEAG Entsorgungs-GmbH
Bottom ash is produced from the non-combustible, mineral coal components in modern coal-fired power plants, which are sintered and cooled down in a water quench. In the dry bottom boilers of these power plants, pulverized coal is burnt at temperatures around 1200°C (2200°F). At these temperatures, the carbon is combusted, but the melting point of the non-combustible, mineral components is not exceeded.
The powdery ash particles are carried along with the flue gas stream, and the biggest portion is extracted as fly ash through electrostatic precipitators. Some of the particles, however, stick to each other on their way through the boiler, forming agglomerations by sintering. Due to their higher weight, these agglomerates can no longer be carried by the flue gas stream. They fall into a water quench below the boiler. The resulting porous material is the steasint bottom ash. By means of pre-storage, an average material humidity of 20 to 25 Wt.% can be achieved. In power plants with dry bottom boilers, up to 10 Wt.% of the ash produced is bottom ash.
Properties
Due to its porous structure, steasint has material characteristics similar to those of natural and artificial lightweight aggregates. Macroscopically, steasint is a humid, fine and lightweight sand with a gray to brown color and a compact, slaggy particle shape. steasint is produced with a particle size distribution of 95 Wt.% smaller than 10 mm and a large portion (about 50 Wt.%) of fine particles smaller than 1 mm. Most of the particles larger than 10 mm are only loosely sintered agglomerates with a low strength. steasint is normally used in the original production quality. However, on demand it can also be sieved to achieve certain particle sizes.
Particle size distribution of steasint
steasint is very environment-friendly. Due to its production process, steasint is a washed material. Therefore the amount of soluble components in steasint bottom ash is comparable to the values normally measured in excavated material.
Applications
In consideration of the applicable regulations, steasint bottom ash can be used just like a natural mineral material. Due to its material properties, steasint is suitable for a wide variety of qualified applications.
Currently steasint is mostly used in its unbound form in the area of earthwork and road construction and as an additive for the production of bricks.
Approved by the German Instutite for Building Technology (Deutsches Institut für Bautechnik, Berlin), steasint is also used as an additional or – mainly for mortars – exclusive lightweight aggregates.
Besides these main application areas, steasint is also suitable for use as a substratum component for greenroof construction and for soil enhancement in agriculture.
isteasint® is a registered trademark of STEAG Entsorgungs-GmbH