What Does Garnet Abrasive Mean?
A garnet abrasive is an abrasive blasting material consisting of minerals from the garnet family, which includes almandite, andradite, grossularite, pyrope and spessartite. It is used as a non-toxic alternative to slags and silica sand. While expensive, garnet abrasives are cost-effective because garnet has a Mohs hardness value between 7 and 8, allowing recycled usage. It also has the benefit of low dusting, which keeps the blast area clean.
Both wet and dry blasting applications can use garnet abrasive. Blasting with garnet abrasive can be used for surface cleaning, coating removal and water-jet cutting, and because it is non-toxic, it is used for marine applications as well.
Corrosionpedia Explains Garnet Abrasive
Garnet, a classification referring to a crystalline configuration rather than chemical composition, provides some variation in the composition of garnet abrasives. Mixtures may be pink, red-brown or greyish-brown. Densities vary between 135-150 lbs/ft3.
The ability for the granular form of garnet to be used as an abrasive comes from its Mohs hardness range between 7 and 8. When launched at high speeds, the garnet granules will clean tough surfaces and resist fracturing, allowing for recycling of the garnet abrasive. Various granule sizes from coarse to fine are available and are used for different applications.
A critical advantage of garnet abrasive over silica sand or slag is for occupational health. Silica exposure can cause deadly and chronic damage in the form of silicosis. Slag, on the other hand, may contain trace amounts of toxic minerals. The end result of sand blasting with garnet abrasives is much cleaner as well, with low dust formation and a lack of embedment of garnet particles into the surface.
While garnet abrasives are more costly than alternative abrasives, its recyclability and clean blasting may reduce costs, making garnet abrasives possibly more cost-effective.
Garnet abrasives are particularly effective for:
- Aluminum and fiberglass structures
- Bridges, docks and shipyards
- Powder coating and denim blasting
- Industrial painting
- Hangar decks
- Confined spaces where low dusting is required