Recommendations for anti-corrosion coatings on solvent-based metal storage tanks
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This post was last edited by Wang Wei2 on 2023-8-16 at 11:18. Recommendations for anti-corrosion coatings on solvent-based metal storage tanks: 1. Purpose of anti-corrosion protection for metal solvent tanks. As we all know, when metal tanks are used to store solvents such as toluene, xylene, and propylene, there are two purposes to anti-corrosion protection of their metal surfaces. The first is to avoid corrosion of the metal by the storage medium ； The second is that rust contaminates the medium when metal corrodes. Benzene solvent does not corrode metals, but moisture is present at the bottom of the storage tank; this leads to electrochemical corrosion of the metal at that bottom, and the resulting corrosion products contaminate the product, causing it to be unsuitable for use. Therefore, corrosion protection for solvent tanks involves preventing corrosion of the metal surface; more importantly, it is about avoiding contamination of the product by the rust products formed on the metal. 2. Characteristics of benzene-based solvents: Metal storage tanks are used to store benzene-based substances, including benzene, toluene, xylene, etc. Benzene (C₆H₆) is an organic compound and the simplest aromatic hydrocarbon. At room temperature, it is a colorless, sweet-smelling, oily transparent liquid; its density is less than that of water. It has a strong distinctive odor, is flammable, and toxic. Benzene is insoluble in water but soluble in organic solvents; it can also be used as an organic solvent itself. It is a solvent for fats, resins, iodine, etc. Benzene is an excellent organic solvent; it has a strong ability to dissolve organic molecules as well as some non-polar inorganic molecules. It is miscible with most organic solvents, except for polyols such as glycerol and ethylene glycol. Inorganic substances are insoluble in benzene, with iodine and sulfur being slightly soluble. Benzene is non-corrosive to metals. 3. Selection of anti-corrosion materials: General organic solvents have the ability to dissolve organic polymer resins; therefore, it is not appropriate to use organic polymer resins such as epoxy resins, furan resins, or phenolic resins as topcoats in solvent tanks to serve as an isolation layer for anti-corrosion purposes. Only inorganic materials can be used as anti-corrosion coatings, such as inorganic zinc-rich coatings.
The following recommendations are given for the anti-corrosion coatings of solvent-based metal storage tanks: 1. Choose inorganic material coatings: Since organic solvents can dissolve most organic polymer resins, it is not suitable to use such resins as coating materials. Inorganic materials, such as inorganic zinc-rich coatings, should be selected. 2. Consider the corrosion properties of the medium: Select an appropriate anti-corrosion coating based on the corrosion characteristics of the solvent to be stored. For example, benzene-based solvents are not corrosive to metals, but moisture may be present at the bottom of metal storage tanks, leading to electrochemical corrosion; therefore, it is necessary to prevent corrosion on the metal surface. 3. Be careful to prevent contamination by rust products: The rust products of metals can contaminate the products, resulting in them being unsuitable for use. Therefore, when selecting an anti-corrosion coating, the issue of contamination of the product by the rust products of the metal must be taken into account. In summary, for anti-corrosion coatings on solvent-based metal storage tanks, it is recommended to use inorganic material coatings, with the choice being determined by the corrosive properties of the solvents and the need to prevent contamination by rust products. .