1. Active agent: It is a common method to clean the dirt on the surface of Marble Sculpting such as terrazzo and marble. There are two types of surfactants: ionic and non-ionic. Their molecules contain two kinds of genes, polar and non-polar. The principle of cleaning is to use the properties of surfactants to reduce interfacial tension, wetting, adsorption, emulsification, solubilization, and dispersion to make dirt molecules fall off and disperse, thereby achieving cleaning. Effect.
2. Alkali cleaning: Use the saponification and emulsification functions of alkaline chemicals to loosen and disperse dirt. Commonly used alkaline solutions are aqueous solutions such as sodium hydroxide and sodium carbonate, which are mainly used to eliminate oil stains. There are two types of oil stains, saponifiable and non-saponifiable. Saponifiable oils are animal and vegetable oils, which can form soaps and dissolve in water when exposed to alkali, so they are easier to remove. With the help of emulsifiers, it can reduce the binding force between oil stains and attachments and fall off. Common emulsifiers include trisodium phosphate, sodium silicate, etc.
3. Acid cleaning: It is widely used in
stone carving cleaning, especially for granite. Hydrochloric acid, sulfuric acid, nitric acid, and hydrofluoric acid are mostly used in inorganic acids; citric acid, oxalic acid, and sulfamic acid are mostly used in organic acids. If sulfuric acid is used to remove rust, sulfuric acid reacts with iron oxide to form iron sulfate, which can be dissolved in water, so rust can be removed. However, the corrosion problem of inorganic acid cleaning is worthy of great attention, especially for carbonate
stone sculpture such as marble. The acid or acid radicals remaining in the micropores may damage the stone sculpture for a long time. Even if buffering agents are added, it is difficult to avoid corrosion problems. It is suitable for cleaning with organic acids or other organic substances that are less corrosive and easy to purify.
4. Complexing agent cleaning: Use complexing agent to complex or chelate various scale-forming metal ions to form soluble complexes for cleaning. Commonly used organic chelating agents include EDTA, DTPA and NTA. For example, EDTA (ethylenediaminetetraacetic acid) can generate polysodium salts, the common ones are disodium salts or trisodium salts, which have strong complexing ability to various scale-forming metal ions.
5. Electrochemical cleaning: With the help of the electric field force between the two polar plates, the ions or polar molecules in the dirt move according to a certain rule, or promote the electrochemical reaction, so that the pollutants desorb, move or undergo chemical changes to achieve the purpose of cleaning . For example, electric current can reduce the adsorption force of iron ions in granite micropores, increase the diffusion coefficient, and generate electric pulses. Remove rust on the granite surface and in a certain depth below the surface.
6. Solvent cleaning: It uses the solvent's ability to dissolve the dirt. If the composition of the pollutants is known, it is very effective to choose a specific solvent. For example, many organic solvents, such as toluene, xylene, butyl acetate, etc., have a strong ability to dissolve grease or oil stains. It is generally faster to remove oil stains with organic solvents than to remove oil stains with lye. The disadvantage is that organic solvents Volatilization may cause environmental impact.
7. Biochemical cleaning: mainly for biological pollutants. People have discovered the erosion and pollution of microorganisms on stone sculpture for a long time. The effective cleaning method is to use targeted biochemical cleaning agents for killing, dissolving, decomposing, and stripping.
