Hebei Messi Biology Co., Ltd. stated that in the rubber and plastics industry, magnesium hydroxide flame retardant has the advantages of good thermal stability, no volatilization, no precipitation, and no production of corrosive and toxic gases. It also has flame retardant, smoke elimination, It has multiple functions of being anti-drip and filling, and has gained widespread attention.
The production of magnesium hydroxide by the brucite method is environmentally friendly, and the obtained magnesium hydroxide has high fluidity. The main component of brucite is magnesium hydroxide, and its theoretical composition includes 69.12% magnesium oxide and 30.88% water. Brucite belongs to the trigonal crystal system and is commonly found in flaky aggregates and sometimes in fibrous aggregates; its cleavage surface is pearlescent, its hardness is 2.5, and its specific gravity is 2.3 to 2.6g/cm3.
At present, the main methods for processing brucite into high specific surface area magnesium hydroxide include rolling mill, jet mill, stir mill, ring roller mill and wet stir mill. However, the production mechanism of the above processes is usually high-speed shearing, collision or Due to the role of crushing, the magnesium hydroxide product has a wide particle size distribution, large breakpoints, and the flake structure is easily destroyed; in addition, the currently commercially available magnesium hydroxide powder produced from brucite has a specific surface area of 6 to 12 m2/g. The flame retardant and smoke suppression effect is still not good.
The invention provides a method for preparing magnesium hydroxide with a high specific surface area, which includes the following steps: mixing brucite raw ore particles and an aqueous solution of a dispersed grinding aid, and performing wet ball milling to obtain ball abrasives; the aqueous solution of the dispersed grinding aid The dispersing grinding aids in the method include sodium polyacrylate, sodium lauryl sulfate and sodium hexametaphosphate; the ball grinding materials are dried and winnowed in sequence to obtain the high specific surface area magnesium hydroxide; the high specific surface area The specific surface area of magnesium hydroxide is ≥20m2/g. The examples show that the high specific surface area magnesium hydroxide provided by the present invention has a specific surface area of 20.833~22.416m2/g, a high specific surface area; an oxygen index of 28.5~28.9%, and a maximum smoke density It is 86.24~88.98kg/m3, which has good flame retardant and smoke suppression effect.