Acid-Proof Lining Bricks
Dense, impermeable refractory bricks engineered to resist concentrated acids, alkalis, and corrosive media. Used for chemical plant flooring, acid storage tanks, pickling baths, and industrial linings. Acid resistance from ≥98% to ≥99.5% across three grades.
Available Grades & Specifications
Three grades matched to the severity of chemical exposure and required service life. All grades bonded with CNSL (cashew nut shell liquid) resin or furan resin for maximum chemical resistance.
Standard Acid-Proof Brick
General-purpose acid-proof brick for moderate chemical exposure environments. Suitable for flooring, wall cladding, and drainage channels in chemical plants, battery manufacturing facilities, and industrial wastewater treatment systems where sulfuric and hydrochloric acid concentrations are below 70%.
- Acid resistance ≥ 98%, water absorption ≤ 8%
- Bulk density ≥ 2.10 g/cm³, compressive strength ≥ 60 MPa
- Compatible with CNSL resin mortar for full chemical seal
- For chemical plant floors, tank surrounds, industrial drainage channels
Dense Acid-Proof Brick
Reduced porosity and higher density for demanding chemical service. The Dense Grade is specified for acid storage tanks, pickling baths, and electrochemical cell linings where direct immersion in concentrated acid or alkali solutions occurs. Its lower water absorption minimises capillary uptake and sub-surface corrosion.
- Acid resistance ≥ 99%, water absorption ≤ 5%
- Bulk density ≥ 2.25 g/cm³, compressive strength ≥ 80 MPa
- Low porosity reduces capillary acid penetration over time
- For acid storage tanks, pickling bath linings, galvanizing facilities
Heavy-Duty Acid-Proof Brick
The highest-specification acid-proof brick for the most aggressive chemical environments, including concentrated sulfuric acid (>95%), mixed acids, and combined acid-plus-thermal cycling conditions. Near-zero porosity, maximum density, and premium furan resin bonding provide the longest service life in extreme chemical contact.
- Acid resistance ≥ 99.5%, water absorption ≤ 3%
- Bulk density ≥ 2.40 g/cm³, compressive strength ≥ 100 MPa
- Near-zero apparent porosity — highest barrier to chemical penetration
- For concentrated H₂SO₄ tanks, mixed acid reactors, fertiliser plant digesters
Technical Specifications
| Grade | Acid Resistance | Water Absorption | Bulk Density | Compressive Strength | Bond System |
|---|---|---|---|---|---|
| Standard | ≥ 98% | ≤ 8% | ≥ 2.10 g/cm³ | ≥ 60 MPa | CNSL Resin |
| Dense | ≥ 99% | ≤ 5% | ≥ 2.25 g/cm³ | ≥ 80 MPa | CNSL / Furan |
| Heavy-Duty | ≥ 99.5% | ≤ 3% | ≥ 2.40 g/cm³ | ≥ 100 MPa | Furan Resin |
Acid resistance tested per GB/T 8488 in 20% H₂SO₄ at 80°C for 24h. Standard size: 230×114×65 mm. Matching CNSL resin mortar supplied separately.
Industry Applications
Acid-proof lining bricks are specified wherever aggressive chemical media contact a structural surface — from petrochemical plants to food processing facilities.
Frequently Asked Questions
Acid-proof lining bricks must be laid with a chemically resistant mortar — typically CNSL (cashew nut shell liquid) resin mortar for Standard and Dense grades, or furan resin mortar for Heavy-Duty applications. Standard Portland or aluminosilicate mortars are not acid-resistant and must not be used. Firebrics supplies matching CNSL resin mortar with every acid-proof brick order.
Yes — the silica-rich composition (SiO₂ >65%) offers good resistance to most mineral acids (H₂SO₄, HCl, HNO₃) as well as moderate-concentration alkalis. For environments with strong NaOH or KOH (above 20%), specify the Heavy-Duty grade and consult our technical team for appropriate mortar selection, as alkali resistance varies by concentration and temperature.
Acid-proof lining bricks are designed primarily for ambient to moderate temperature service (up to approximately 300°C). The CNSL/furan resin bond systems begin to degrade above 200–250°C, so for applications combining both chemical attack and high temperature (e.g. above 300°C), a different product combination — typically high alumina brick with acid-resistant castable — is required. Contact our team to review your specific conditions.
Related Products
Insulation Mortar
CNSL resin mortar for chemically resistant jointing of acid-proof bricks.
Conventional Castable
High-temperature castable for areas where acid-proof bricks meet thermal linings.
Custom Refractory Shapes
Acid-proof tiles, sump liners, and special profiles cut to your drawings.
Get a Quote for Acid-Proof Lining Bricks
Provide your chemical media, concentration, temperature, and required dimensions. Our team will recommend the right grade and matching mortar system within 24 hours.