The raw material of high-purity magnesite is ed natural super graed siderite,and is made through the processes of the floatation, purity,fine-grinding, briquetting and super high temperature calcining in oil shaft kilns.It is the excellent raw material for the brick making and the unshaped refractory material making. High Purity Magnesite MgO :96-97.5% Size :0-10mm or powder Packing: One ton bag;25/50 PP bag