Highland acid resistant brick (SiO₂ 65–75%, acid resistance ≥98% in 98% H₂SO₄ at 80°C/48h, water absorption ≤0.5%, CCS ≥30MPa) is engineered for pickling tank linings, concentrated acid storage vessels, chemical plant floor systems, and flue gas desulfurization tower walls.
Also referred to as acid proof brick, acid brick, or chemical resistant brick, this specialized refractory product blocks acid penetration through its dense sintered structure — outperforming standard fire bricks, high-alumina bricks, and fire clay bricks in corrosive environments. ISO 9001:2015 certified. Standard sizes stocked: 150×75×25mm, 230×113×40mm, 230×113×65mm.
thermal shock resistance ≥5 cycles at 180°C water quench, acid resistance ≥98% in H₂SO₃ and dilute H₂SO₄ service at operating temperatures of 50–180°C.
specified at acid resistance ≥99.8% and water absorption ≤0.2% — the threshold required to suppress acid wicking through the brick body to the tank shell in concentrated H₂SO₄ (98%+), HNO₃, and mixed acid service at temperatures up to 120°C.
water absorption ≤0.3% blocks acid penetration to tank shell, CCS ≥35MPa resists mechanical impact from strip steel and part loading, acid resistance ≥98% in 98% H₂SO₄ at 80°C/48h.
Acid-resistant brick is made of quartz, feldspar and clay as the main raw materials
thermal shock resistance ≥5 cycles at 180°C water quench, acid resistance ≥98% in H₂SO₃ and dilute H₂SO₄ service at operating temperatures of 50–180°C.
specified at acid resistance ≥99.8% and water absorption ≤0.2% — the threshold required to suppress acid wicking through the brick body to the tank shell in concentrated H₂SO₄ (98%+), HNO₃, and mixed acid service at temperatures up to 120°C.
water absorption ≤0.3% blocks acid penetration to tank shell, CCS ≥35MPa resists mechanical impact from strip steel and part loading, acid resistance ≥98% in 98% H₂SO₄ at 80°C/48h.
Acid-resistant brick is made of quartz, feldspar and clay as the main raw materials
Acid resistant brick is a silica-rich refractory brick manufactured from high-purity quartz sand and feldspar, pressed at 1500 tons and sintered at 1250–1350°C for 48 hours. The resulting dense structure (bulk density 2.3–2.5 g/cm³) creates a near-impermeable barrier against hydrochloric acid, sulfuric acid, nitric acid, and most mineral acids — making it the standard lining material for equipment handling corrosive liquids.
The key difference between acid resistant brick and ordinary refractory brick lies in chemical composition and firing protocol. Standard fire bricks prioritize high-temperature mechanical strength but offer minimal acid protection (fire clay bricks typically achieve ≤80% acid resistance). High-alumina bricks focus on refractoriness above 1500°C but only reach ~85% acid resistance. In contrast, acid proof bricks trade some maximum service temperature for superior acid resistance — maintaining structural integrity in environments where conventional bricks dissolve within months.
| Property | Acid Resistant Brick | Fire Clay Brick | High-Alumina Brick |
|---|---|---|---|
| SiO₂ content | 65–75% | 50–60% | 40–50% |
| Al₂O₃ content | 20–30% | 30–40% | 55–80% |
| Acid resistance (98% H₂SO₄, 80°C, 48h) | ≥98% | ≤80% | ~85% |
| Water absorption | ≤0.5% | 10–15% | 8–12% |
| Max service temperature | 1000°C continuous | 1300°C | 1500°C+ |
| CCS | ≥30MPa | 25–30MPa | 40–60MPa |
| Primary use | Acid lining | Furnace lining | High-temp zones |
For equipment handling acids at ambient to moderate temperatures (up to 1000°C), acid resistant bricks are the correct specification. For high-temperature kilns above 1200°C with acidic atmospheres, a combination lining using acid brick in lower-temperature acid zones and high-alumina brick in upper-temperature zones is recommended.
Highland supplies three grades of acid resistant bricks to match different operating conditions. Selecting the correct grade depends on acid concentration, temperature range, and mechanical stress.
SiO₂ 65–75%, acid resistance ≥98%, water absorption ≤0.5%. Designed for ambient-to-moderate temperature acid contact (up to 100°C continuous): pickling tanks, acid storage vessels, chemical flooring, and electroplating baths. This is the most widely specified grade and covers the majority of acid proof brick lining applications.
Reinforced formulation with added mullite for thermal shock resistance (≥5 cycles, 600°C water quench). Service range 120–600°C with maintained acid resistance. Used in FGD tower hot gas entry zones, acid vapor ducts, and chemical calcination kiln feed sections where both acid attack and thermal cycling occur simultaneously.
High-grade variant (acid resistance ≥99.8%, water absorption ≤0.2%) with custom curved, wedge, or irregular profiles radius-matched to specific equipment geometries. Chemical resistant brick is the industry term for this premium grade — it eliminates wedge-shaped joints in cylindrical tanks and reactor vessels, which are the primary failure point in standard rectangular-brick cylindrical linings. Thickness adjustable from 25mm to 100mm.
| Parameter | Standard Grade | High Grade |
|---|---|---|
| SiO₂ | 65–75% | 70–78% |
| Al₂O₃ | 20–30% | 18–25% |
| Acid resistance (98% H₂SO₄, 80°C, 48h) | ≥98% | ≥99.8% |
| Water absorption | ≤0.5% | ≤0.2% |
| Bulk density | 2.3–2.5 g/cm³ | 2.4–2.6 g/cm³ |
| Cold compressive strength | ≥30MPa | ≥35MPa |
| Refractoriness | 1650°C | 1700°C |
| Max service temperature | 1000°C continuous | 1000°C continuous |
| Thermal shock resistance | ≥3 cycles | ≥5 cycles |
| Standard sizes | 150×75×25 / 230×113×40 / 230×113×65mm | |
| Lead time | 30–40 days (standard) / 40–60 days (custom) | |
Acid resistance by acid type: ≥98% in H₂SO₄ (98%), ≥97% in HCl (37%), ≥96% in HNO₃ (65%), ≥92% in HF (40%). The reduced resistance to hydrofluoric acid is inherent to silica-based brick — for HF service, carbon-filled acid brick or special formulations are available on request.
Pickling tank linings (HCl/H₂SO₄), acid washing lines, acidic wastewater treatment ponds. Standard 230×113×65mm brick with sodium silicate mortar. Service life 3–5 years vs 6–8 months for ordinary brick.
Concentrated acid storage tanks, reactor vessel linings, acid transport pipe interiors. High-grade chemical resistant brick with ≤0.2% water absorption + anti-permeation membrane underlayer.
FGD tower and duct linings in coal-fired and waste incineration plants. Thermal cycling 50–180°C with dilute H₂SO₄/H₂SO₃ exposure. High-temperature grade with expansion joints at 1.5m intervals.
Glass etching acid storage, acid leaching tanks, wastewater treatment pools. Curved custom bricks for cylindrical tank walls. HF-resistant formulations available for glass etching lines.
Proper installation is as critical as brick quality for long-term lining performance. The most common lining failure mode is not brick degradation but acid attack at mortar joints. Key requirements:
Selecting the right acid resistant brick supplier determines not only product quality but also long-term lining performance and technical support quality. Key evaluation criteria:
Highland Refractory manufactures acid resistant bricks under ISO 9001:2015 with CE certification, third-party tested per batch, with 30–40 day standard lead time and 40–60 day custom lead time. Test reports accompany every shipment.
Submit your application details — acid type, concentration, temperature, and equipment type. We will recommend the correct grade, size, and mortar system within 2 business hours.
Contact Us: info@highlandrefractory.com
Acid-resistant brick is made of quartz, feldspar and clay as the main raw materials
thermal shock resistance ≥5 cycles at 180°C water quench, acid resistance ≥98% in H₂SO₃ and dilute H₂SO₄ service at operating temperatures of 50–180°C.
specified at acid resistance ≥99.8% and water absorption ≤0.2% — the threshold required to suppress acid wicking through the brick body to the tank shell in concentrated H₂SO₄ (98%+), HNO₃, and mixed acid service at temperatures up to 120°C.
water absorption ≤0.3% blocks acid penetration to tank shell, CCS ≥35MPa resists mechanical impact from strip steel and part loading, acid resistance ≥98% in 98% H₂SO₄ at 80°C/48h.
