The type of white fused alumina suitable as a sandblasting abrasive is mainly determined by the purity grade and particle size specification of the product, which can be selected according to different sandblasting requirements such as processing precision, workpiece material and cost budget. The specific suitable types and their application scenarios are as follows:
- By purity grade
- High-purity white fused alumina (Al₂O₃ content ≥ 99.5%): It is the preferred choice for high-demand sandblasting scenarios. This type of white fused alumina undergoes high-temperature smelting and acid pickling to remove impurities, with extremely low iron oxide and magnetic substance content. It is especially suitable for sandblasting processes that strictly prohibit iron powder residue, such as the surface treatment of stainless steel workpieces, electronic components and precision hardware. After sandblasting, the workpiece surface appears pure white without residual impurities, eliminating the need for subsequent cleaning procedures. In addition, its high purity ensures stable hardness and cutting performance, making it ideal for pre-treatment of stainless steel mirror polishing and surface finishing of high-end auto parts.
- Ordinary high-purity white fused alumina (Al₂O₃ content around 99%): It is a cost-effective option for general industrial sandblasting. It has slightly more impurities than the ultra-high-purity type but can fully meet the needs of conventional sandblasting operations, such as rust removal and deburring of ordinary alloy steel, surface roughening before coating of general mechanical parts, etc. It is widely used in ordinary industrial production due to its balanced performance and reasonable price, and is the most commonly used type of white fused alumina in the sandblasting field.
- By particle size specification
- Coarse-grained white fused alumina (12–80 mesh): It is suitable for rough sandblasting tasks that focus on efficiency, such as removing thick rust layers on large steel structures, old paint coatings on ship hulls, and burrs on large mechanical castings. The large particle size gives it strong impact and cutting force, which can quickly complete surface cleaning and shaping. However, the surface roughness after processing is relatively large, so it is not suitable for precision surface treatment.
- Medium-grained white fused alumina (90–240 mesh): It is a versatile type for medium-precision sandblasting. It is applicable to surface treatment scenarios such as deburring of hardware accessories, surface roughening before spraying of auto parts, and cleaning of tool and measuring tool surfaces. Its particle size distribution is uniform, which can balance processing efficiency and surface quality. After sandblasting, the workpiece surface has a moderate roughness, which can enhance the adhesion of subsequent coatings without damaging the base material.
- Fine-grained and micro-powder white fused alumina (above 280 mesh): It is designed for precision sandblasting and finishing. The ultra-fine particles have mild cutting force and are suitable for surface polishing of precision mechanical parts, atomization aesthetic processing of glass and acrylic crafts, and ultra-fine grinding of semiconductor materials. In particular, micro-powder white fused alumina performs excellently in wet sandblasting operations, as it can achieve a smooth and bright surface effect without causing scratches to the workpiece surface.
In addition, it should be noted that there is no need to choose special types such as ceramic-bonded or nano-grade white fused alumina for conventional sandblasting. The former is more suitable for manufacturing wear-resistant floors and large abrasive tools, while the latter is only used in high-tech ultra-precision processing fields and is not cost-effective for ordinary sandblasting applications.
