湿型砂鲕化率检测方法的研究

Study on Oolitization Rate Test Method of Used Sand

采用磷酸法和盐酸-氢氧化钾法对湿型砂鲕化率进行了测量试验,并对其中的关键步骤进行了改进。试验结果表明:将加热方式改为随炉加热,可以避免试样表面出现焦炭膜;将煮沸工艺改为煮沸+搅拌工艺,可以使鲕化层去除更完全;将盐酸-磷酸法中的盐酸取消,简化为磷酸法,可以减小金属元素损失,使测量值更准确;将盐酸-氢氧化钾法的反应时间从25 min延长至30 min,可以解决砂粒未洗净的问题;使用少量盐酸滴入到沉淀与砂粒混合的溶液中,沉淀可以被有效去除,解决两者难以分离的问题。

The oolitization rate of green molding sand was measured with phosphoric acid method and hydrochloric acid-potassium hydroxide method,and the their key steps was improved.The test results indicated that:the heating method being changed to the furnace heating,could avoid the coke film on the surface of the sample,changing the boiling process to the boiling+stirring process could make the oolitization layer removal more completely,simplifying the hydrochloric acid in the hydrochloric acid-phosphoric acid method to the phosphoric acid method could reduce the loss of metal elements and make the measurement value more accurate,extending the reaction time of the hydrochloric acid-potassium hydroxide method from 25 min to 30 min could solve the problem of sand grain being not washed.Adding a small amount of hydrochloric acid drops into the solution of the precipitate mixed with the sand particles,the precipitate could be effectively removed,solving the problem of difficult separation between the two.