无色结晶或熔块状。有吸湿性。易溶于水，水溶液呈强酸性。商品常为近于70%的焦硫酸钾的30%硫酸氢钾的混合物。
熔点  325 °C  
密度  2.28 g/mL at 25 °C(lit.) 
溶解度  H2O: 0.1 M at 20 °C, clear, colorless 
水溶解性  MAY DECOMPOSE 

HG 3-921-76
99.99% metals basis:


外观Appearance                                     White powder or chunks
X-射线衍射X-Ray Diffraction               Conforms to Structure
纯度Purity                                               ≥99.99% Based on Trace Metals Impurities
ICP Major Analysis                                Confirms Potassium and Sulfur Components
纯度Purity (Titration by NaOH)           98.5-101.5 %
总痕量金属杂质total metallic impurities ≤100ppm by ICP Atomic emission

项目ltem                                               分析纯         化学纯
                                                              (AR)           (CP)
含量(K2S2O7)Assay,%                    ≥ 98.0           97.0
澄清度试验Clarity                                合格           合格
水不溶物lnsoluble matter in water,%   ≤ 0.01           0.015
氯化物(Cl)Chloridea,%                    ≤ 0.001          0.003
磷酸盐(PO4)Phosphate,%               ≤ 0.001          0.0015
钙及镁(以Ca计)Calcium and magnesium,% ≤ 0.005          0.01
铁(Fe)Iron,%                                       ≤ 0.001          0.003
砷(As)Arsenic,%                               ≤ 0.0003         0.0005
重金属(以Pb计)Heavy metals,%     ≤ 0.0005         0.002

危险品标志                     C 
危险类别码                     34 
安全说明                        26-36/37/39-45 
危险品运输编号            UN 3260 8/PG 2
WGK Germany             3
HazardClass                 8 
PackingGroup              II

主要用作温浊水的凝聚剂，起净化水质作用。造纸工业用作上浆剂，与松香乳液配合用于纸张施胶，提高纸的抗水强度。医药工业用作防腐剂、收敛剂、止血剂。加制成枯矾，可作为外用收敛止血药；配成一定浓度水溶液，可用于防止水稻皮炎；制成氢氧化铝，可配制成胃病药。与青饲料一起拌和，可用于牲畜疾病防治。也是中药材半夏、南星的腌制剂等。轻工工业用作黄色医用玻璃的着色剂。制革工业用作铝鞣剂。 
 
密封保存。