What is the rust? Rust is when iron-containing substances enter the interior of the stone or the iron compounds in the stone react with chemical substances in the environment to form yellow or yellowish brown marks on the surface of the stone. Chemically explained: it is made of iron reacting with oxygen in moist air. This chemical reaction requires three components, namely Fe (iron), O2 (oxygen), H2O (water).
The reasons for the formation of stone rust yellow:
First, primary rust spots. The chemical composition of stone contains a certain amount of iron oxide elements, such as golden thread beige, silver thread beige, Shaanna beige, white hemp and so on. These iron-containing substances are easily oxidized to form rust when they come into contact with air in a humid environment. With the flow and diffusion of water in the micropores of the stone, irregular chloasma will appear on the surface of the stone.
The second is secondary rust spots. In the process of mining, processing, transportation, paving, and use of the stone, rust is directly immersed, or iron remains on the surface of the stone, which oxidizes and diffuses over time, resulting in rust and yellow spots. In areas with severe acid rain, acid rain will continuously dissolve iron-containing substances around the stone (such as dry pendants, scaffolding, etc.), and transfer the rust to the stone surface.
The third is dissolving rust spots. In the process of use and maintenance, the stone is polluted by strong acid (such as hydrochloric acid, sulfuric acid, nitric acid, etc.) or cleaned with strong acid. The strong acid will dissolve the iron around the stone and form an iron-containing solution. These solutions will penetrate and remain inside the stone, and with the action of alkaline substances and the reduction of acidity, these iron elements will turn into rust.
To determine the type of rust spots:
The first type of rust spot is the rust spot on the stone itself, which is difficult to deal with thoroughly. Because to deal with rust spots, it is necessary to react these iron, and the iron contained in the stone is difficult to completely remove.
The second and third rust spots are relatively easy to deal with. The specific treatment process of rust spots is: cutting and blocking - lifting protection - prescribing the right medicine - medicine night removal - anti-oxidation treatment - protection treatment.
1. Cutting block. Block the incentives for the rust spots that continue to be produced on the stone, such as iron and water, so that the rust spots will not continue to expand.
2. Release the protection. If the stone has been protected, the original protective function of the stone should be removed first, otherwise the rust-spot treatment agent cannot penetrate into the stone and play a corresponding role. Solvent-based (oil-based) protective agent can be removed with degreasing ointment and DEC21; water-based (water-based) protective agent can be removed with DEC21.
3. Prescribe the right medicine. Use professional marble (marble) rust remover to remove rust, such as marble rust remover, granite rust remover, MAR, NO RUG, etc.
