The High Efficiency of White Corundum Micropowder in Stone Polishing

To be honest, when it comes to “stone polishing,” many people’s first thought might be large machinery, noisy factories, and grinding discs in the hands of experienced polishers. But if you truly understand the industry, you’ll discover that it’s often the nearly invisible micropowders that truly determine the final results. For example, the white corundum micropowder we’re discussing today is this “master of polishing” hidden behind the scenes. When I first started working in this field, I was also puzzled: Isn’t it just polishing stone? Any “powder” doesn’t matter. But after seeing more, I realized that choosing the right micropowder can make a world of difference in the results.

1. What is white corundum micropowder? Why is it suitable for polishing?

White corundum, to put it simply, is a man-made, high-purity aluminum oxide (Al₂O₃). It’s harder than natural corundum, with a Mohs hardness of 9.0, second only to diamond and silicon carbide. As the name suggests, “micropowder” refers to the material that has been crushed and sieved to a micron-level fine powder. You might ask: “Won’t this material scratch the stone?” This brings us to its advantages: high hardness yet excellent toughness: white corundum particles are resistant to breakage, maintaining uniform cutting force during polishing; chemical stability: they do not react with minerals in the stone, causing no discoloration or corrosion; and highly controllable particle size: they offer a comprehensive service from rough grinding to fine polishing, making them particularly suitable for multi-stage polishing processes. These characteristics make it particularly suitable for processing common decorative stones such as marble, granite, and artificial stone.



II. What exactly makes it so “efficient” in actual polishing?

Many people think polishing is simply about bringing a bright finish to the stone surface, but that’s not the case. A good polishing process must quickly remove scratches while gradually improving the gloss, while also avoiding over-polishing or damaging the grain.

1. Coarse, medium, and fine polishing, seamlessly completed

For example, when working with marble floors:

Rough polishing (80#-200#): Use a coarser white corundum powder (such as W40-W20) to quickly smooth the surface and remove deep scratches;

Medium polishing (400#-800#): Switch to a finer powder (such as W14-W7) for initial polishing;

Fine polishing (1500#-3000#): Even powders with W3.5 or less can be used to achieve a mirror-like finish.

You’ll find that powders of the same material, in varying particle sizes, can be used throughout the entire polishing process, eliminating the need for frequent material changes—saving time, effort, and errors.

2. Strong adhesion and fast polishing

Compared to traditional materials like diatomaceous earth and cerium oxide, white corundum powder, with its sharp-angled particles (rather than spherical), is more easily absorbed into the stone surface, resulting in higher cutting efficiency. We’ve conducted a comparison: polishing the same piece of granite with white corundum micropowder can achieve the same glossiness in 1/3 less time than polishing with ordinary materials.

3. Not picky about stone material, highly versatile

White corundum is practically universal, whether it’s highly acidic marble or granite with a high silica content. This is especially true for mixed artificial stone (such as quartz), which contains both resin and mineral materials. Many traditional abrasives can easily cause it to become matte or hazy, while white corundum consistently delivers sharpness.

4. Long lifespan and lower overall cost

While white corundum micropowder may be slightly more expensive per unit than some traditional materials, it is wear-resistant, resists dulling, and offers a high reusability rate. Often, a batch of material can cover 20%-30% more surface area, making it more cost-effective in the long run.

Ⅲ. Are there any real-world examples? Is it really that effective?

Let me give you a personal example: Last year, a hotel lobby was renovated. The beige marble floor was covered in scratches from years of use and had a gloss level of less than 30. The construction team initially used ordinary polishing powder, but after three coats, the results were still unsatisfactory. They then switched to a polishing paste based on white corundum micropowder. After just two coats, they achieved a gloss level of over 75 degrees. The final gloss level upon delivery was close to 85. The client immediately renewed the contract. The master craftsman said something truly heartfelt: “This thing is like getting a new weapon in a game—it kills monsters quickly and doesn’t cost you any health.”

IV. Future Development Trends? Will It Be Replaced?

Currently, white corundum powder maintains a solid position in stone polishing, but it is also evolving:

Finer and finer particle size: Nano-grade white corundum powder (e.g., W1.0 and below) has begun to be used for ultra-mirror polishing, particularly in high-end decoration and artistic stone processing;

Combined applications: For example, when mixed with cerium oxide and diamond powder, it achieves a balanced cutting force and gloss, suitable for special stone materials;

Enhanced environmental protection and safety: A new generation of water-based polishing slurries is gradually replacing older dry powders, reducing dust pollution and making them more suitable for automated machining;

Conclusion: Small Materials, Big Impact

Often, we focus on the obvious—like the brand of the polishing machine or the reputation of the construction team—but overlook the details that truly impact the results. White corundum powder is such a “low-key, yet crucial” material. If you are renovating your own house or working in the stone care industry, the next time you are involved in the polishing process, you might as well ask one more question: “What kind of micro powder are we using?” The final effect may be completely different because of this question.

This article references content from the following blog:

https://www.xinliabrasive.com/The-High-Efficiency-of-White-Corundum-Micropowder-in-Stone-Polishing.html