... SGS,Intertek,BV. ISO9001:2008 GB/T 19001-2008 Specification:Magnesium Sulphate Hepta. (white and crystal)Spec.:MgSO4 7H2O:99.5% ... , porcelain, printing, porcelain, fireproof materials and feed additives of magnesium salt, etc..How to Control the Quality,Service and Price ... A. We cooperate and invest large scale national factories of Magnesium sulphate. B. We have own warehouse and select good quality to ...