铸铁中铬的快速测定方法

Rapid Speed Testing Method About Chromium in Chromium Cast Iron

采用 (NH4 ) 2 S2 O8氧化 ,(NH4 ) 2 Fe(SO4 ) 2 还原测定铬。原理是 :在试样溶解过程中 ,把铬变成 3价铬 ,然后通过(NH4 ) 2 S2 O8把 3价铬氧化成 6价 ,再以 (NH4 ) 2 Fe(SO4 ) 2 还原剂 ,将其还原为 3价 ,根据所消耗的还原剂 (NH4 ) 2 Fe(SO4 ) 2 的量 。

Chromium is tested with oxidized (NH 4) 2S 2O 8 and reduced (NH 4) 2Fe(SO 4) 2 . Theory:Chromium is changed into Cr 3+ during solution, then it can be oxidized to C 6+ with (NH 4) 2S 2O 8, and reduced into Cr 3+ with (NH 4) 2Fe(SO 4) 2. According to the quantity of (NH 4) 2Fe(SO 4) 2, the number of chromium is determined.