We can offer tire special magnesium oxide.
this product feature:

mgo content: 92%
Fe: 0.005%
Calcium oxide: 1% max
water soluble matter: 1% max
HCl insoluble : 0.2% max
Bulk density:0.23g/ml
325 mesh pass: 99% min

Raw materials: lake brine, dolomite, magnesium hydroxide.
control temperature: 650 °C to 950 °C
quality: ISO9001-2008
Packing: 1kg,10kg,15kg,20kg per bag
Min Order: 20kg

learn more info, tell me.
best regards
Michael lee