Among the many marbles, white marble is undoubtedly one of the most widely used stones. White marble is widely used in high-grade luxury building’s wall and coverings, but white marble is very fragile and difficult to manage, especially easy to turn yellow. Which are the reasons of white marble turning yellow?
a) the structure and composition of the stone itself
It has been found that on the surface and texture of white marble, there are iron minerals with particle sizes ranging from 2 microns to several hundred microns, some of which are distributed on the surface of the plate, and some are enriched in the grain. These iron minerals are susceptible to oxidation, and when the iron-containing minerals randomly dispersed in the marble are oxidized to form yellow or brown hydrated iron oxides, the surface defects are formed.
The second type of turning yellow of white marble panels comes from the organic matter inside the marble, which is present in the formation of marble. These water-soluble organic substances are often brownish yellow when reacted with alkaline water. If the marble floor or wall panel is not waterproofed on the back of the board during the wet installation, the alkaline water of the cement slurry penetrates the marble and reacts with the organic matter in the marble to produce a colored product. These colored products are watered. When it comes to the surface of the stone, it forms the second pollution of the stone surface. Even during the use of the stone after installation, due to climatic reasons, whenever there is water through the cement concrete and then seep out the surface of the stone, it will always bring out colored organic pollutants to the surface of the stone.
b) External pollution
1) Turning yellow caused by wear
As the polished surface of the marble wears, the dirt is carried into the pores of the marble surface with walking, and the dirt causes the surface of the white marble to appear yellow.
2) Turning yellow caused by incorrect care
The most common incorrect care is to wet the floor with a dirty mop. The dirt brought by the dirty mop accumulates in the marble, causing the marble surface to become yellow and contaminated.
3) Turning yellow caused by waxing
When a wax is used to polish a marble surface, the thick wax layer turns yellow due to its own aging.
4) Turning yellow caused by crystal surface treatment
The steel wool used in the crystal surface treatment has tiny fine powder remaining on the micropores of the polished marble surface, which led to white marble turn yellow, especially when the marble is treated in the wet state, and the yellow change is easy to occur.
5) Turning yellow caused by the installation process
Before the installation of the marble floor or wall surface, although the stone specification plate is subjected to the so-called six-sided waterproof treatment: the bottom surface is waterproof and the four sides and the front surface are treated with the permeable waterproofing agent. If such a six-sided waterproofing treatment is done very well, the quality of the selected waterproofing material is also guaranteed, and theoretically, water-related yellowing should not occur again. But the fact is that even the six-sided waterproofing of the stone board surface before installation is considered to be doing very well, and the yellowing of the board surface after installation still occurs from time to time.
The turning yellow phenomenon of the stone related to the installation is mainly caused by two aspects. First, due to the installation size, the on-site cutting destroys the original waterproof treatment of one side; another possible situation is that the construction environment is messy and during the construction process. The cement slurry falls on the surface of the board. In order to prevent the falling cement slurry from drying up on the surface of the board, wipe the fallen cement slurry with a wet towel. At this time, it is very possible to wipe the strong alkaline cement water into the surface of the board. Dark cracks, because even if the surface of the permeable waterproofing treatment has been made, it is impossible for the tiny water repellent molecules to form a protective film covering the crack at the crack to protect the crack shield. Therefore, the coverage of the waterproofing agent at the crack is very limited. When installing, use a gray knife to scrape off the side of the specification board with cement slurry, which will also destroy the waterproof treatment that has been done. If the cement water is accidentally brought into the crack of the board surface when wiping the board surface, the yellowing of the board surface is sooner or later than whether it will turn yellow.
c) Prevention of white marble turning yellow
The turning yellow caused by the internal composition and structure of the marble occurs through external conditions. This external condition is water and oxygen in the air. Therefore, as long as the water is effectively prevented from passing through the interior of the stone,the stone turned yellow is effectively suppressed. An effective means of preventing water from passing through the interior of the stone is to waterproof the back side of the board prior to installation of the stone. Regardless of the performance of the waterproofing agent, its waterproof performance will gradually decline due to environmental influences. This is why, after the first application of the waterproofing agent, it is repainted at regular intervals to repair the deterioration of its waterproof performance.
The turning yellow of white marble caused by external causes can be prevented by reasonable use and maintenance, such as placing fiber carpet at the entrance to remove the sand or other hard particles before entering the marble paving area, reducing the external hard particles. The wear of the stone board surface. The mop for cleaning the floor should be kept clean. The water used for mopping the floor must be clean. After the floor is finished, wipe off the water on the floor. Use dry wiping as much as possible. In case of conditions, it is best to use marble cleaning solution to maintain.
Floor waxing has proven to be a drawback to the marble deck maintenance method. Firstly, the gloss of the polished surface of the wax is not long. On the other hand, most of the wax has a blocking effect on the pores of the stone ventilation, so that the normal gas channel adjusted by the climate is blocked. Finally, when the accumulated wax layer is yellowed due to aging and needs to be removed, a wax removing agent must be used, and the use of the wax removing agent seriously affects the indoor air quality.
4)Crystal Face Treatment
The crystal face treatment is a commonly used polishing treatment on the marble floor. Choosing the right crystal face agent can obtain a layer of light film that is dense and does not affect the breathability of the stone surface. However, when performing the crystal face treatment, if it is polished with steel wool, the sprinkled steel wool fine powder must be cleaned with a vacuum cleaner. Any fine powder of steel wool remaining on the ground may become a source of yellowing of the board surface.
5) Stone Installation
The stone installation practitioners must have a certain professional foundation, understand the reasons for the yellowing of the stone, and have the necessary skills to install the stone, keep the construction environment clean and tidy, and avoid the yellowing of the stone caused by the installation. Scientifically care for stone to avoid the introduction of iron that will yellow the stone from the cleaning water or floor polishing process. Use a good quality osmotic water repellent to regularly protect the floor and reduce the time and opportunity for water to contact the stone.
Therefore, effective prevention of yellowing of white marble should be a comprehensive measure. The treatment of the back of the stone board is particularly important in the case where the concrete floor or the wall surface is not effectively waterproofed. Selecting a quality-assured waterproof adhesive to waterproof the back of the board is the most important step in all measures.