标准摘要
[中文适用范围]： 规定了氟化钠/三氟化铝摩尔比约为 3 至 1.7 的天然和合成材料的测试方法。 本方法适用于五氧化二磷含量不超过0.02%（m/m）的产品。 该程序包括通过碳酸钠和硼酸的混合物对测试部分进行碱熔。 将熔化的物质溶解在过量的硝酸中，使得pH值在0.7和0.9之间。 在明确规定的酸度、温度、时间和试剂浓度条件下形成（黄色）氧化钼硅酸盐。 在酒石酸存在下选择性还原并在约 815 nm 的波长下测量。 [外文原描述]： Specifies methods of test for natural and synthetic materials having a molar ratio sodium fluoride/aluminium trifluoride between 3 and 1,7 approximately. The method is applicable to products the phosphorus pentoxide content of which does not exceed 0,02 % (m/m). The procedure consists in alkaline fusion of a test portion by means of a mixture of sodium carbonate and boric acid. Dissolution of the fused mass in excess nitric acid so that the pH value is between 0,7 and 0,9. Formation of the (Yellow) oxidized molybdosilicate under clearly defined conditions of acidity, temperature, time and concentration of reagents. Selective reduction in the presence of tartaric acid and measurement at a wvelength of about 815 nm.
英文名称Cryolite, natural and artificial — Determination of silica content — Reduced molybdosilicate spectrophotometric method