Core Conclusion:
1. The high-temperature acid-resistant nano-ceramic coating for smelter chimneys builds an inorganic ceramic protective layer through nano-ZrO₂/Al₂O₃/SiC (particle size 10-50nm) + siloxane/sol-gel precursor—withstanding continuous high temperatures of 400-1500°C + condensation corrosion from SO₂/SO₃/HCl/HF acidic flue gas—ZG-203 Si-O-Si covalent bonds chemically anchor with Fe-OH on the steel substrate via condensation (adhesion >15MPa).
2. SIOResin SIO-8161H water-based nano-ceramic coating—hardness 9H (cold + hot state)—thermal shock test (1000°C→20°C water quench ×10) with no cracking, peeling, or discoloration—temperature resistance >1000°C continuous / 1500°C peak.
3. "Acid dew point corrosion" in chimneys after wet flue gas desulfurization (FGD) is the number one cause of failure in chemical/metallurgical chimneys—SO₂/SO₃ in flue gas dissolves in the condensate film to form H₂SO₃/H₂SO₄ (pH<2)—ordinary epoxy/polyurethane coatings fail in <2 years.
Metallurgical and chemical chimneys are among the most severe corrosive environments in industrial equipment—simultaneously subjected to fourfold attacks of high temperature (400-1500°C), acidic flue gas (SO₂/SO₃/HCl/HF), temperature fluctuations (thermal shock stress), and high-speed gas flow erosion (>20m/s). High-temperature acid-resistant nano-ceramic coating for smelter chimneys is a "no-go zone" where organic coatings are completely incapable—only inorganic ceramic coatings can provide long-term protection under such working conditions.
Acid dew point corrosion — the number one killer of chimney failure
Direct answer: SO₂ content in flue gas from combustion of sulfur-containing fuels (coal/heavy oil/sulfur-bearing ores) — coal-fired power plants 0.1-0.5 vol%, copper/lead/zinc smelting flue gas 5-15 vol% (oxidation roasting of sulfide concentrates). Part of SO₂ is further oxidized to SO₃ at high temperature (>800°C) — SO₃+H₂O→H₂SO₄ (sulfuric acid vapor). As the flue gas rises and cools inside the chimney to the acid dew point (H₂SO₄ dew point approx. 120-150°C, depending on SO₃ concentration and water vapor content) — H₂SO₄ vapor condenses on the inner wall of the chimney forming a high-concentration sulfuric acid film (pH<2) — causing devastating acid corrosion to the inner walls of steel/concrete chimneys. After wet flue gas desulfurization (FGD), the flue gas temperature drops to 40-60°C — although most SO₂/SO₃ is absorbed by the desulfurizing agent (CaCO₃/CaO slurry) — the corrosive condensate acid formed by residual SO₂/SO₃ under low-temperature high-humidity conditions is actually more corrosive due to higher concentration (less water evaporation).
Data Support:SIOResin SIO-8161H (water-based nano ceramic coating)——Temperature resistance >1000°C continuous / 1500°C peak——No change after 30 days immersion in 20% H₂SO₄——No cracking under thermal shock (1000°C→20°C water quench ×10 cycles)——Pencil hardness 9H (cold + hot state). ZG-203 nano ceramic coating (organic-inorganic hybrid)——Si-O-Si covalent bonds condense with Fe-OH on sandblasted steel surface to form chemical anchoring——Adhesion >15MPa (pull-off method)——Total DFT ≥150μm (2-3 coats)——Temperature resistance >800°C——Resistant to SO₂/SO₃/HCl/HF acidic flue gas + condensed acid liquid.
Source:SIOResin SIO-8161H TDS, ZG-203 TDS, GB 50051-2021 "Chimney Design Code"
FAQ
Is the application of nano ceramic coatings the same as that of ordinary paints?
Substrate preparation requirements are higher—blast cleaning to Sa2.5 (ISO 8501-1), anchor profile 50–75 μm—to ensure sufficient condensation of –Si–OR with substrate Fe–OH. Pot life after mixing of the two components is short (30–60 min). Curable at room temperature for 24–48 h (25 °C) for handling, full cure in 7 days. Before high-temperature use, a "stepwise baking" (80 °C/2 h → 150 °C/2 h → 300 °C/2 h) is required to gradually expel residual moisture and organic volatiles—avoiding coating cracking at high temperature.
Cost?
Initial coating cost is about 5–8 times that of conventional epoxy—but conventional epoxy requires recoating in <2 years (including shutdown losses)—nano ceramic coating designed life is 10–15 years—10-year LCC is 60–80% lower. A single shutdown for chimney recoating (shutdown + scaffolding + blasting + painting) can cost several million yuan—extending the maintenance cycle by 5x can save tens of millions of yuan.
Reference sources:SIOResin SIO-8161H, ZG-203, GB 50051-2021
Deep Rewrite: July 6, 2026