Among many marble colors, white marble is undoubtedly one of the most widely used marble stone. White marble is used in high-end and luxurious walls, floors, background walls, stairs, countertops, etc. Some people play white marble in tricks, such as Clothes, light bulbs, fruit bowls, megaphones, and even toilets.

The simplicity and elegance of white marble, noble temperament, softness and delicacy are really addictive, and the decorative effect is even better, which is simply fantastic. Its mild tones, white like snow, and pure beauty like snowflakes allow many designers to make full use.

But at the same time, it is also the most loved and feared material. However, white marble is hypocritical, fragile, and difficult to serve in terms of anti-pollution, which makes some users regret it, especially the fact that white marble is easy to turn yellow, which makes many people who love it to stay away .

In order to solve the quality problems , we have to analyze the internal and external factors, thoroughly understand the natural character of marble, and the key factor to cause the quality problem, and then we can solve the fundamental problem. So what causes white marble to turn yellow? How to keep the original appearance of white marble?

The oxidation of iron minerals contained in white marble is considered to be the main reason for the yellowing of marble. Since most marbles have a single and uniform color except for the texture part, when the iron-containing minerals randomly dispersed in the marble are oxidized to form yellow or brown hydrated iron oxides, defects on the slab surface are formed, and the aesthetic feeling is stains, especially for white marble.

The iron in white marble mainly exists as ferrous sulfide, iron carbonate and magnesium iron silicate. These iron minerals are dispersed in the marble matrix or enriched in the marble texture.

When these ferrous minerals on the stone surface are oxidized by oxygen in the air to form ferric iron and combine with water to form hydrated ferric hydroxide, what we often call rust is formed. If no protective measures are taken, this phenomenon of marble spit yellowing will appear 8-12 months after the marble is placed.

The yellowing phenomenon of white marble is the result of the combined effect of oxidation and hydration on the ferrous minerals on the surface of the stone. These two conditions are indispensable. Unlike soaking in ionized water, white marble soaked in alkaline solution is very prone to yellowing. Carrara white marble is the most serious.

The second type of yellowing pollution on white marble slabs comes from organic matter inside the marble, which is present during the formation of the marble, and its structure is similar to humus.

These water-soluble organics present in the marble react with alkaline water and often show a brownish yellow color. Due to the existence of this organic matter inside the marble, when the marble floor or wall panel without waterproof treatment on the back of the board is installed by wet sticking, the alkaline water of the grout seeps through the marble and reacts with the organic matter in the marble to produce a colored product , When these colored products are brought to the stone surface by water, the second pollution of the stone surface is formed.

For sure,there are some other reasons to cause the marble yellowing.For example improper care.

How to prevent white marble to turn in yellow?

1. Due to the internal composition of marble

Structurally induced yellowing occurs through external conditions. This external condition is water and oxygen in the air. Therefore, as long as water is effectively prevented from passing through the interior of the stone, the yellowing caused by the composition and structure of the stone will be effectively suppressed.

2. An effective way to prevent water from passing through the interior of the stone is to waterproof the back of the board before the stone is installed.

Early stone slab back waterproofing treatments were brushed with siloxane/silane penetrating waterproofing agents. Facts show that coating the back of the board with this waterproofing agent cannot effectively inhibit the occurrence of stone lesions including yellowing. Penetrating water repellents have certain limits.

No matter how good the waterproofing sealant is, its waterproof performance will gradually decline due to the influence of the environment. This is why after the first application of the waterproofing agent, it is necessary to repaint it at regular intervals to repair the deterioration of its waterproof performance. For this reason, penetrating water repellents are only suitable for surfaces that are ready to be repainted, such as the front of a floor or an outward-facing wall panel.

Effective prevention of white marble yellowing should be a comprehensive measure. In the case that the cement floor or wall is not effectively waterproofed, the treatment of the back of the stone slab is particularly important. Selecting a quality-assured waterproof adhesive to waterproof the back of the board is the most important step in all measures.

How to deal with the yellowing white marble?

Once you find the yellowing of the white marble slab, you must first find out the cause of the yellowing. Before turning the suspicion of the cause of yellowing to rust, make sure that the yellowing is not caused by aging wax or other external factors. After eliminating factors other than iron, start preparing for rust removal.

At present, there are various brands of iron and yellow removers in stone care shops. Although no product discloses the basic chemical composition, most of the iron and yellow removers on the market are acidic. Due to the poor acid resistance of marble, many acidic rust removers also have great erosion on the board surface while removing rust. Excessive erosion of the marble slab will cause permanent damage to the slab.

Therefore, when using a rust remover, remember to stick several layers of toilet paper on the surface of the stone when removing yellowing, and then pour the rust remover on the paper. Wait for about two hours, the yellow will gradually decrease, and the yellow can be removed after a few times. Professional stone care personnel generally use weakly acidic or even neutral cleaning agents to minimize damage to the stone.

For stubborn rust spots, the paste method is used, that is, mix the rust remover and diatomite with water to make a paste, then apply the paste on the rust spots, cover with plastic film and seal the periphery with self-adhesive tape. Remove the dried paste after 24 hours, and collect the dissolved iron with a special cleaning agent after the removal is completed.

This last step is very important, because in the process of removing rust, when the iron ions diffuse to the board surface, if the iron ions diffused on the board surface are not collected cleanly, the secondary yellowing will soon occur, and the area will be larger. wide. Of course, you can also remove yellowing at home by yourself (as shown in the picture below)

For more information about the problem solving or more about white marble,pls do not hesitate to contact us.

By email connie@excellentstone.com