Carbon Brick Specification (Non-Impregnated)
| Property | Unit | Value |
|---|---|---|
| Thickness | mm | 10 to 100, tolerance ± 1 mm |
| Density | g/cc | 1.5 |
| Compressive strength | kg/cm² | 350 to 400 |
| Flexural strength | kg/cm² | 100 to 150 |
| Tensile strength | kg/cm² | 60 |
| Porosity | % | 18 to 24 |
| Water absorption | % | 12 to 18 |
| Carbon content | % | 99 |
| Ash content | % | 1 |
| Thermal conductivity | W/mK | 4 to 6 |
| Abradability index | Morgan scale | 120 |
| Temperature resistance | °C | 750 |
| Loss of weight in chemical duty | % | less than 1 |
Where Carbon Bricks Are Used
- Phosphoric acid plants, where fluoride impurities attack clay bricks
- Hydrofluoric acid and fluoride salt handling
- Sulphuric acid plants, refineries and petrochemical units
- Strong hot alkali service, where clay bricks and silicate mortars are not suitable
- Mixed acid and alkali duty where the chemistry changes during the process
Impregnated and Non-Impregnated Carbon Bricks
A carbon brick is naturally porous, with porosity of 18 to 24% in the non-impregnated grade. For service where liquid must not pass into the brick, impregnated carbon bricks are used, in which the pores are filled to reduce permeability. In both cases the lining is built over an impervious membrane, so that anything passing through the brickwork cannot reach the concrete or steel.
Carbon Bricks or Acid Proof Bricks?
| Service | Recommended brick |
|---|---|
| Sulphuric, hydrochloric, nitric and most mineral acids | Acid proof bricks to IS 4860 |
| Hydrofluoric acid, fluoride salts, fluosilicic acid | Carbon bricks |
| Strong hot alkalis | Carbon bricks |
| High temperature acid service up to 900 C | Acid proof bricks in potassium silicate mortar |
| Mixed acid and alkali duty | Either, depending on the chemistry. Send details. |
Strongly oxidising conditions should always be checked with us before carbon is specified. Send the chemical, its concentration and the operating temperature, and we will confirm whether carbon brick is needed or whether acid proof bricks with a resin mortar will do.
Mortar for Carbon Bricks
Carbon bricks are bedded and jointed in carbon filled furane resin mortar, which keeps the joints free of the silica fillers that fluorides attack. We manufacture both the bricks and the mortar. Details of the full mortar range are on our acid proof mortar and cement page.
Supply and Export
We supply carbon bricks in standard sizes and in thicknesses from 10 mm to 100 mm, across India and for export, and we carry out carbon brick lining with our own applicators. Call +91 9825006626 or email info@acidproof.com.