In the marking cleaning, the ordinary steel generally goes through the process of sand blasting before use, which can remove rust, oxide skin and other impurities. Before pickling and passivation, stainless steel will also undergo sand blasting treatment for surface cleaning to remove the possible oil stain on the surface and make the surface roughness meet certain requirements, or achieve certain process purposes or produce sanded surface to reduce reflection. Generally, RZG dust-free garnet sand blasting abrasive (natural emery) can be used. RZG dust-free garnet sand is selected from high-quality iron aluminum garnet rock ores. It has high hardness, high density, good toughness, sharp corners and sharp edges. It is a high-grade, pure natural non-metallic sandblasting abrasive. RZG dust-free garnet sand processed according to the highest quality standard has reasonable particle size distribution, less dust, extremely low soluble salt (chloride) content and conductivity, and does not contain free silicon, heavy metals and other harmful components, meets the requirements of iso 11126, iso 11127, PSPC and other specifications, and meets the most stringent industrial and military technical requirements. RZG dust-free garnet sand can go deep into holes and uneven parts for cleaning, and thoroughly remove oxide skin, rust, soluble salts and other contaminants. The sandblasted surface has no embedded objects, no adverse bumps and pits, and can easily obtain the highest sandblasting level of Sa3. The surface roughness can reach 30-80 μ m, achieving stronger coating adhesion and longer coating service life. In addition, the hardness of RZG dust-free garnet sand is 7.5-8.0, the density is 4.2g/cm3, the edges and corners are sharp, and the cutting effect is excellent. The sandblasting area is large per unit time, the sand consumption is small per unit area, and the sandblasting cost is low. Thanks to the excellent toughness and low brittleness of RZG garnet sandblasting abrasives, they have a low crushing rate during sandblasting. They can be recycled for 5-10 times depending on the application, further reducing the use cost of customers. Because the proportion of garnet is large, 4.0-4.2, and the settling speed is fast, there is less dust in the sand blasting process. After repeated washing in the production process, the dust content is extremely low, and the operating environment will be better than quartz sand. In fact, the pure, non chemical and non hazardous RZG garnet dust-free sand blasting abrasive has replaced the metal slag (copper ore sand), river sand, quartz sand, etc. originally used. As a dust-free sandblasting abrasive, dust-free garnet sandblasting abrasive not only has the characteristics of high quality and low price, but also can avoid silicosis caused by free silicon and some cancers caused by toxic heavy metals. Recycling can also reduce costs.