... :white crystalProperties:White crystalline, virulent, melting point, boiling point °C 925 °C 1560, insoluble in water, soluble in acid and nitric acid ... ,/%≤0.01≤0.02N/%≤0.002≤0.005Sodium (Na) /%≤0.01≤0.02possii(K) /%≤0.005≤0.01Calcium (Ca) /%≤0.05≤0.1Iron (Fe)/%≤0.0001≤0.0002Strontium (Sr) /%≤0.02≤0.1Heavy metal/%≤0.005≤0 ...