How does acid-resistana brick maintain its internal structure and remain undamaged when subjected to continuous corrosion from strong acids of varying concentrations?
Publish Time: 2026-01-15
Acid-resistana brick, an inorganic non-metallic material specifically designed for highly corrosive environments, is widely used in critical components such as pickling tanks, acid storage ponds, flue gas desulfurization towers, and underground sewage systems in industries like chemical, metallurgical, electroplating, and pharmaceutical. Its core value lies in its ability to maintain structural integrity and stable performance even after prolonged exposure to high concentrations of sulfuric acid, hydrochloric acid, nitric acid, and even mixed acids. This exceptional corrosion resistance is not accidental but stems from a "multi-layered protective barrier" constructed by its dense microstructure, low porosity, chemically inert components, and high-temperature sintering process.
1. Low Porosity and Dense Structure: The First Line of Physical Defense
Acid-resistana brick is typically made from high-quality quartz, feldspar, clay, and acid-resistant aggregates, sintered at temperatures above 1300℃. During this process, the raw materials undergo glassy melting and recrystallization, forming a highly dense ceramic body. Its water absorption rate is generally below 0.5%, and its apparent porosity is controlled below 3%, far lower than that of ordinary building bricks. Such low porosity means that acid cannot easily penetrate the brick's interior through capillary action. Even when the surface comes into contact with a high concentration of strong acid, the corrosive medium is limited to a very shallow surface layer and cannot penetrate deep enough to cause structural damage, thus effectively preventing gradual corrosion "from the outside in."
2. Inert Chemical Composition: The Intrinsic Foundation for Acid Corrosion Resistance
The main chemical components of acid-resistana brick are silicon dioxide and aluminum oxide, with SiO₂ content often exceeding 70%. Silicon dioxide exhibits extremely strong chemical stability against most inorganic acids at room temperature. Al₂O₃ further enhances the material's heat resistance and resistance to alternating acid and alkali corrosion. This composition, dominated by acidic oxides, keeps it in a thermodynamically stable state in acidic environments, fundamentally avoiding degradation phenomena such as dissolution, expansion, or pulverization.
3. Glassy Phase Network: A "Self-Healing" Mechanism for Sealing Microcracks
During high-temperature sintering, some components melt to form a continuous glassy phase, filling the spaces between crystal grains. This amorphous network not only enhances the overall strength of the brick but also acts as a "sealant"—even if micron-level cracks develop due to thermal stress or mechanical impact during use, the dense glassy phase effectively blocks the path of acid penetration along grain boundaries. Furthermore, the glassy phase itself is rich in SiO₂, exhibiting excellent acid resistance, ensuring that even at the microscale, corrosive media have difficulty finding a breakthrough.
4. Adaptability to Different Acid Concentrations
It is worth noting that acid-resistana brick exhibits slight differences in its resistance to strong acids of varying concentrations. For example, it demonstrates excellent stability in low to medium concentrations of sulfuric acid; while still outperforming most materials in fuming sulfuric acid or high-temperature concentrated nitric acid environments, selection must be based on specific operating conditions. However, thanks to its overall chemical inertness and dense structure, acid-resistana brick maintains long-term stability even when subjected to concentration fluctuations or intermittent immersion. It does not undergo phase transitions or volume expansion due to changes in acid concentration, thus avoiding the risk of structural collapse.
The ability of acid-resistana brick to remain steadfast under continuous strong acid corrosion is a perfect combination of materials science and high-temperature ceramic technology. Its dense structure forms a physical barrier, its inert components provide chemical defense, and its glassy phase network achieves microscopic sealing. These three elements work synergistically to prevent corrosive media from entering, reacting with, or causing damage. In harsh industrial environments, acid-resistana brick is not only a protective material but also a crucial cornerstone for ensuring safe production and extending facility lifespan.
