Causes of Granite Rusting and Prevention Methods

Granite is widely used in architectural decoration for its beauty and durability, but certain types are prone to rusting. The causes of rusting are mainly natural attributes and human factors.

Causes

Natural Attributes

• Iron Content: The iron content in granite reacts with oxygen and water when exposed, forming iron oxide, which is rust.

• Mineral Content: The amount and type of other minerals in granite can also affect its tendency to rust, with granite containing more biotite tending to rust more than that containing more feldspar.

Human Factors

1. Friction during Cutting: Friction between the saw blade and the stone can cause iron shavings to adhere to the slab, leading to oxidation if not cleaned promptly.

2. Iron Ions in Water: Iron ions in groundwater, runoff water, or processing water can cause rust spots.

3. Chemical Cleaning Residue: Residual iron ions left on the surface after cleaning with chemicals like oxalic or hydrochloric acid can oxidize and form rust spots if not thoroughly rinsed off.

Prevention Methods

Avoid Prolonged Contact with Water and Damp Environments

• Prolonged exposure to water and damp environments can promote the oxidation of iron, leading to rusting.

Regular Cleaning and Maintenance

• Regularly clean the granite surface with neutral cleaners and a soft cloth, avoiding acidic or alkaline cleaners.

Choose Corrosion-Resistant Granite

• Opt for granite varieties with lower iron content that are less likely to rust, such as black or gray granite.

Implement Protective Measures

• Apply waterproof coatings or cover with waterproof materials to granite that may be exposed to water or dampness for extended periods.

Conclusion

While the natural attributes of granite cannot be changed, the risk of rusting can be significantly reduced by taking appropriate preventive measures. Proper maintenance and care are crucial for preserving the beauty and extending the lifespan of granite.