What is the HS code of white corundum?

What is the HS code of white corundum?
The main component of white corundum is the structure
Among them, white corundum segment sand and fine powder are often used in refractory materials
White corundum particle size sand is used to make sandblasting and abrasive tools
Commonly used terms for grinding and polishing of white corundum micro powder
Product code: 28181090