... Industrial Grade Purity: 46% Appearance: flakesApplication: mgo board production K: less than 0.01 Na: Less than ... ventilation pipes, anti-theft covers, fireproof doors and Windows, fire prevention board, partition board, the production of artificial marble and ... , high quality system of fire prevention board, magnesium magnesium packing, decoration board, light wallboard, abrasive, stoves, fireworks ...