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在沸腾的溶液中,硫酸铵水解产生酸,能将碳酸铁矿物选择性溶解。它又能与二价铁生成复合物,加速碳酸铁的溶解,并防止二价铁被氧化,因而不需任何助溶剂和保护措施。由于硫酸铵水解所产生的氢离子浓度较低,鳞绿泥石等易溶硅酸铁的溶解率,均在2％以内。实验表明:样品粒度太粗,溶解速度较慢,在规定时间内浸取不完全,所用的分析样品,必须全部通过200目;取样重量以控制碳酸铁中铁小于30毫克为宜;硫酸钱量在10—40克/100毫升,对测定没有影响;加热煮沸十分重要,它既能增加硫酸铵的水解度和水解的速度,又能除去水解和溶解过程中产生的氨和二氧化碳,还能减少溶液的粘度,增加离子活度,加速碳酸铁矿物的溶解;在玻璃珠存在的情况下,溶液不停地均匀沸腾,可以防止爆沸
In boiling solutions, ammonium sulfate hydrolyzes to produce acids that selectively dissolve iron carbonate minerals. It can also form complexes with ferrous iron, accelerating the dissolution of iron carbonate and preventing ferrous iron from being oxidized, thus eliminating the need for any cosolvent and protection. Due to the lower concentration of hydrogen ions produced by the hydrolysis of ammonium sulfate, the dissolution rate of easily soluble silicic acid such as scales and chlorites is within 2%. Experiments show that: the sample size is too coarse, the dissolution rate is slow, the leaching is not complete within the specified time, the sample used must pass all 200 mesh; sample weight to control iron less than 30 mg of iron is appropriate; sulfuric acid in 10-40 g / 100ml, no effect on the determination; heating boil is very important, it can increase the degree of hydrolysis of ammonium sulfate and hydrolysis rate, but also to remove hydrolysis and dissolution of ammonia and carbon dioxide generated during the process, but also reduce the solution Viscosity, increase ion activity, accelerate the dissolution of iron carbonate minerals; in the presence of glass beads, the solution kept boiling evenly, you can prevent bumping