Standard alum coagulants are made from high-aluminum clays, while low-iron and iron-free grades are made from aluminum trihydrate
, which can have a variety of impurities (Table 1).
The aluminum trihydrate
is then ground and classified using the same procedures as other minerals, and is available in particle sizes from less than 1 [micro]m to several micrometers.
is low in cost and found abundantly in nature.
Widely used are chlorinated paraffins, antimony oxide, boron-compounds such as zinc borate, aluminum trihydrate and phosphate plasticizers.
Aluminum trihydrate splits off water, acting as an "internal extinguisher.
In this regard, magnesium hydroxide is similar to aluminum trihydrate
, another more commonly used hydrated filler.
This fire retardant can be an inorganic filler, such as aluminum trihydrate
, vermiculite, silicate, phosphate, carbonate, or other halogen-free agent.
Huber Engineered Materials recently introduced a flame retardant for pultrusion, resin transfer molding, and bulk molding/sheet molding compounding called MoldX A3 aluminum trihydrate
New surface treatment technologies are opening up new applications for hydrated filler flame retardants such as magnesium hydroxide and aluminum trihydrate
, says Gregory Coughlin, market development manager at Lonza, Inc.
Tsuei developed a benzoxazine resin mixed with a bisphenol A diglycidyl ether and bisphenol S resin containing ferrocene and aluminum trihydrates