... could be used as filling agent for synthetic detergent; used for the manufacturing of chemical products such as ... sodium sulfide, ultramarine, sodium silicate, etc; used for the production of sulfate pulp in the paper industry; ... -ferrous metals, enamels ,soap, etc. 2.Data for reference Item GB/T6009-2003 I group First qualityNormal qualityMedium ... 8~12 99% sodium sulphate anhydrous for industrial use