鱼雷罐用铝碳化硅碳砖中碳化硅的氟硅酸钾滴定法研究

探讨了测定鱼雷罐用铝碳化硅碳砖中碳化硅的氟硅酸钾滴定方法。用KOH和KNO₃混合熔剂在镍坩埚中熔融鱼雷罐用铝碳化硅碳砖，选取熔融温度为700 ℃，熔融时间为15 min的熔融条件，在此条件下进行浸取易于操作，减少了对镍坩埚的损害。采用自制的抽滤装置，即将普通抽滤瓶进行改装，将玻璃砂芯漏斗部分用塑料代替，只需用直径约为40 mm、相当于四分之一张普通滤纸的滤纸进行过滤，过滤时抽滤速度快，滤纸不会穿漏，且吸附的残余酸量很少，易于洗涤和中和。方法用于自制标准样品的测定，回收率在98%～101%之间，相对标准偏差小于5%，能够满足日常分析检测需要。

Study on the potassium fluosilicate titration of silicon carbide in aluminum silicon carbide carbon brick for torpedo ladle

The determination method of silicon carbide in aluminum silicon carbide carbon brick for torpedo ladle by potassium fluosilicate titration was discussed. The sample of aluminum silicon carbide carbon brick for torpedo ladle was melted in nickel crucible using KOH-KNO₃ mixed flux. The melting temperature was 700 ℃ and the melting time was 15 min. The leaching under this condition was easily operated. Meanwhile, the damage to nickel crucible could be reduced. The self-made filtration equipment (the common suction flask was modified. That is, the glass sand core funnel was replaced by plastic. Only a filter paper with diameter of about 40 mm, which was 1/4 of one common filter paper, was required) was used for filtration. The suction filtration speed was rapid to avoid the leakage of filter paper. Moreover, the amount of residual acid was little, which was easy to be washed and neutralized. The proposed method was applied to the determination of self-made standard sample. The recovery rate was 98 %-101 %, and the relative standard deviation was less than 5 %, which could meet the requirements of routine analysis.