Introduction of ZS-1042 desulfurization and anti-corrosion special coating and its application in flue gas spray tower（Anti corrosion coating for spray tower desulfurization tower absorption tower）

1、 Overview of ZS-1042 desulfurization and anti-corrosion special coating products

（1） Core Technology and Working Principle

1. Dense film-forming anti permeabilityThe inorganic organic interpenetrating network has a dense and pore free film-forming structure, which can effectively block the penetration of acidic media such as SO ₂, SO 3, HCl, HF, and alkaline slurries, reduce the medium loss rate, and form a stable isolation and protective layer;

2. Inert packing shieldingCeramic inert fillers with high content in coatings have excellent chemical stability and can resist strong corrosive media such as 95% concentrated sulfuric acid and 10% sodium hydroxide. At the same time, the filler has high hardness, which can improve the wear resistance of coatings and resist the erosion and wear of smoke, dust, and spray slurry;

3. Stress buffering adaptationThe coating contains inorganic ceramic fibers, which can enhance the internal cross-linking and impact resistance, effectively adapt to the thermal expansion and contraction caused by temperature fluctuations during the operation of the flue gas spray tower, and avoid cracking and peeling of the coating due to structural stress;

4. High temperature stability protectionThe synergistic effect of special modified resin and ceramic filler endows the coating with excellent high temperature resistance, which can withstand working conditions of 60-150 ℃ for a long time and 250 ℃ for a short time, and can adapt to the temperature changing environment inside the flue gas spray tower.

（2） Key performance parameters

• Appearance: Thick liquid, with a full and smooth surface after brushing, black color, excellent self-cleaning properties;

• Density: 1.6g/cm ³, two-component system (main agent: curing agent=9:1), strong construction adaptability;

• Corrosion resistance: resistant to 95% sulfuric acid (above 60 ℃) for ≥ 300h without change, resistant to 10% sodium hydroxide (above 60 ℃) for ≥ 500h without change, resistant to neutral salt spray for ≥ 2000h without abnormality;

• Temperature resistance: Long term temperature resistance of 60-150 ℃, short-term (4-hour) temperature resistance of ≥ 250 ℃, short-term (3-minute) temperature resistance of ≥ 800 ℃;

• Mechanical properties: Coating hardness 5H, adhesion level 1, impact resistance ≥ 50cm, flexibility Φ 2mm, sand drop test wear resistance 3.0L/μ m;

• Construction performance: Solid content ≥ 60%, surface drying time ≤ 2h, actual drying time ≤ 24h, recommended dry film thickness of 300 μ m, theoretical coating rate of 1.2 ㎡/kg.

2、 Application of ZS-1042 desulfurization and anti-corrosion special coating in flue gas spray tower

（Anti corrosion coating for spray tower desulfurization tower absorption tower）

（1） Solution to the core pain points of smoke spray tower application

1. Resist strong acid-base corrosionThe dense film-forming structure and inert fillers of ZS-1042 coating can form an effective protective barrier against the corrosion of acidic media such as SO ₂ and SO Ⅲ in the tower, as well as spray slurry. It can withstand strong acidic and alkaline environments for a long time, avoiding coating swelling, peeling, and substrate corrosion, and solving the core problem of insufficient corrosion resistance of traditional materials;

2. Anti erosion and wear protectionThe dust particles in the flue gas and the slurry sprayed at high speed will continuously erode the inner wall of the tower. The high hardness ceramic filler in the coating can significantly improve the wear resistance of the coating. The sand drop test shows a wear resistance of 3.0L/μ m, which can effectively resist erosion wear and protect the integrity of the tower structure;

3. Adapt to temperature fluctuation conditionsThe coating has excellent high temperature resistance and impact toughness, which can adapt to long-term working conditions and short-term high temperature fluctuations of 60-150 ℃ in the flue gas spray tower. At the same time, it can buffer the thermal expansion and contraction stress caused by temperature changes, avoid coating cracking, and solve the problem of traditional materials being damaged due to temperature stress;

4. Extend the operation and maintenance cycle to reduce costsTraditional protective materials have short maintenance cycles and frequent repairs, significantly increasing operating costs. The protection period of ZS-1042 coating can reach 5-10 years (adjusted according to the film thickness), which can significantly extend the operation and maintenance cycle of the flue gas spray tower, reduce maintenance frequency and downtime losses. Calculated based on a single 1000 ㎡ spray tower, it can save more than 30% of annual operation and maintenance costs.

（2） Key points of construction for smoke spray tower

1. surface treatmentRemove dust, oil stains, rust, and brittle coatings from the inner wall surface of the spray tower. Metal substrates should be sandblasted to Sa2.5 level or manually polished to St3 level. Concrete substrates should be leveled and cured, and floating dust should be removed to ensure a surface roughness of 25-40 μ m and improve coating adhesion;

2. Construction methodAir spraying or airless spraying can be used, and brushing can be used in some corners (using the cross method); Strictly mix the coating according to the ratio of main agent: curing agent=9:1, and use it up within the applicable period of ≤ 2h in summer and ≤ 4h in winter after mixing; Recommend a dry film thickness of 300 μ m, which should be applied in 2-3 coats with an interval of at least 2 hours between each coat (after surface drying);

3. drying and curingThe construction environment should be dry and ventilated, with a temperature controlled between 0 ℃ and 40 ℃, to avoid construction in rainy or high humidity environments. The surface drying time should be ≤ 2h, and the actual drying time should be ≤ 24h. Subsequent processes can only be carried out after actual drying. During the curing period, collision and contact with the medium should be avoided;

4. maintenanceCoatings should be stored in a dry, cool, and well ventilated place at a temperature of 0 ℃ -40 ℃, with a shelf life of 24 months; Unused paint after opening should be sealed and stored; Regularly inspect the coating status after construction, and promptly repair any local damage or corrosion points found, which can further extend the protection period.

（3） Practical application case verification

• The coating has no swelling, cracking, or peeling phenomenon, and has excellent corrosion resistance to acidic media such as SO ₂ and HCl;

• The wear amount of the coating in the high erosion area inside the tower (below the spray nozzle) is ≤ 5 μ m, and the wear resistance meets the requirements of the working conditions;

• The operation and maintenance cycle of the spray tower has been extended from 1 year for traditional materials to over 5 years, saving over 200000 yuan in maintenance and downtime losses per tower per year;

• The coating has good stability under temperature fluctuations of 60-140 ℃, and no damage caused by thermal stress has occurred.

3. Summary