Hebei Messi Biology Co., Ltd. said that magnesium oxide can be used for chemical fiber and plastic industry flame retardant, silicon steel sheet production of high-temperature annealing agent, high-grade ceramic materials, electronic industrial materials, chemical materials, binders and additives; wireless electronic industry, high-frequency magnetic bar antenna magnetic device materials, insulating materials, fillers, and a variety of carriers; electrical insulating materials, the manufacture of crucibles, furnaces insulated, conduits, electrode rods, electronic thin plate, glass Cover plate and so on. At present, with the rapid development of electronic equipment, a variety of touch-screen products such as spring, followed by a new industry is about to rise, a new generation of cover glass research is in full swing research, magnesium oxide as the main cover glass products, has been widely valued and studied.
Magnesium oxide is odorless, tasteless, insoluble in water and ethanol, melting point 2852 ℃, boiling point 3600 ℃, magnesium oxide has a high degree of fire-resistant insulation properties. By 1000 ℃ above high temperature burning can be transformed into crystals, rise to 1500 ℃ above the death of burning magnesium oxide or sintered magnesium oxide. Magnesium oxide is alkaline oxide, with alkaline oxides, exposed to air, easy to absorb water and carbon dioxide and gradually become alkaline magnesium carbonate. It is soluble in acid and ammonium salt insoluble in water, its solution is alkaline, insoluble in ethanol.
The magnesium oxide used in cover glass needs to be similar to the form of spheres, and the specific surface area should be below 10m2/g. However, the specific surface area of magnesium oxide prepared by existing technology (soda ash method, caustic soda method) is relatively large, which raises a great deal of difficulty in the production of high-purity magnesium oxide for cover glass.
The present invention discloses a production process of magnesium oxide, including: formulating magnesium chloride solution, purifying magnesium chloride solution and adding it to the reactor, then adding a crystal control agent, ultrasonic; obtaining the mixture; the ethanol atomized material through the carrier gas into the mixture of the reactor; in the stirring conditions, to the mixture of the reactor of the mixture of the material of the ammonia continued to be passed until the precipitation is stable, to stop passing the ammonia, filtration, washing, obtaining magnesium hydroxide; in the stirring conditions, to the mixture of the reactor of the continuous passing of ammonia until precipitation stabilization, stopping passing ammonia, filtering, and washing, obtaining magnesium hydroxide. Wash, get magnesium hydroxide; the magnesium hydroxide will be added to the ball milling tank, and at the same time add the stainless steel grinding ball, to the ball milling tank through the liquid nitrogen, will be magnesium hydroxide and stainless steel grinding ball all submerged in liquid nitrogen, ball milling, collection of ball milled magnesium hydroxide for high temperature calcination, grinding and crushing, to get the magnesium oxide; by the magnesium oxide of the invention’s production process, it can be obtained the purity of 99% or more, the stacking density of more than 1 g/cm3, whiteness greater than 98, specific surface area less than 10 m2/g of magnesium oxide, which meets the requirements for the use of cover glass.
