论文部分内容阅读
草酸—硫酸亚铁铵钼蓝光度法,作为钢铁中硅(Si≤1％)的炉前快速分析方法,目前仍被普遍应用,但实践中发现该法分析结果很不稳定,抽样检验重现性差,当钢样中硅含量约>0.6％时,工作曲线明显下弯,且曲线位置不固定,因此,需要小心操作,甚至每班均需校正。 按原方法,当操作进行到待加钼酸铵溶液时,强调将试样溶液煮沸后立即加入10ml5％钼酸铵溶液,摇匀。再按顺序立即加入2％草酸及1％硫酸亚铁铵溶液各50ml。笔者认为该方法所存在问题就在于此。在操作条件下,由于钼酸铵溶液的温度随季节、昼夜温差等情况不同而发生较大变化,所以,当它与试液等体积混合后,就直接影响到硅钼黄的形成温度,即影响到硅钼黄的形成速度,使其尚未完全形成就被迫进行下一步反应,造成钼蓝吸收曲线不稳定,分析结果
Oxalic acid-ammonium ferrous ammonium molybdate blue photometric method, as a fast analysis method of silicon in steel (Si≤1%), is still widely used, but in practice it is found that the results of this method are unstable and the sampling test is repeated Poor, when the steel content of about> 0.6%, the working curve significantly lower, and the curve position is not fixed, therefore, need to be careful operation, or even need to be corrected in each class. According to the original method, when the operation is to be added ammonium molybdate solution, the sample solution is boiled immediately after adding 10ml5% ammonium molybdate solution, shake. Then immediately add 2% oxalic acid and 1% ammonium ferrous sulfate solution each 50ml. I think the problem lies in this method. Under operating conditions, the temperature of ammonium molybdate greatly varies with the season, temperature difference between day and night, so when it is mixed with the volume of the test solution, it directly affects the formation temperature of silicon molybdenum yellow, that is, Affect the rate of silicon molybdenum yellow formation, it has not been fully formed to be forced to the next reaction, resulting in molybdenum blue absorption curve is unstable, the results of the analysis