1. The formation of yellow spots is due to the high iron content in the raw materials of Shandong gray hemp stone. Carbon dioxide and water in the air invade the surface of the stone, react with the iron in the stone to produce iron oxide, which is then discharged through the capillary pores of the stone and formed.
2. Originally, stone had defects such as black spots and color pigments, which would be treated during processing, but would reappear during use.
Technical factors:
1) During the sawing process, iron filings remain on the surface of the stone, which have not been cleaned thoroughly. During use, rust is generated after being oxidized by water.
2) The quality of anchored steel bars is poor and prone to oxidation reactions, resulting in rust spots.
3) Shandong gray hemp stone products are packaged with grass ropes and colored cardboard boxes. During storage or long-distance transportation, exposure to water and moisture can cause discoloration of the stone under high temperature conditions.
4) When using wet installation of stone, during the curing process of cement mortar, pigments and impurities in the mortar penetrate into the surface of the stone through the gaps and cracks of the stone, forming color spots, color lines, etc., which can easily occur in some light or white stones.
Usage factors:
During the process of using stone, there may be some pollution and stains caused by human factors, such as ink stains, food stains, paint stains, chemical stains, etc. Of course, there may also be other factors.
There are two methods for removing rust spots and stains from Shandong gray hemp stone: physical removal and chemical removal.
Physical removal method: Use grinding and polishing to remove the macula. But this method is more suitable for flat stone that has not yet been installed. It is not easy to handle installed stone or irregular stone, and the cost of labor and materials is also too high. The key is that the effect is not good. After all, after installation, only a small handheld grinder can be used for polishing, and the effect is not ideal.
Chemical cleaning method: Neutralizing the original reaction through the rules of related chemical reactions to remove stains. For example, iron is oxidized by water to produce rust. We know that the mixture of ferrous hydroxide and ferric hydroxide is the main component of rust. Therefore, as long as the correct chemical reagents and targeted methods are used, cleaning can be carried out conveniently and quickly. There are two commonly used chemical cleaning agents, hydrochloric acid rust remover and oxalic acid rust remover. The advantages of these two cleaning agents are convenience, simplicity, and low cost. But after processing, it should be thoroughly cleaned with cleaning agents in a timely manner. If not rinsed with water in a timely manner or not thoroughly rinsed, the treated area will turn yellow again or produce new pollution. Some highly oxidizing cleaning agents can cause the stone to continue oxidizing, losing its original color, becoming lighter or whiter.