稀土精矿中稀土的测定,一般采用氟化分离或碱分离,草酸盐重量法。钍的测定是在氟化分离后,用六次甲基四胺将稀土与钍分离,然后用偶氮胂Ⅲ比色法测定钍。操作手续十分冗长。后来改用磷酸三丁脂—二甲苯萃取,偶氮胂Ⅲ比色测定钍及EDTA络合滴定稀土,虽此法对前法有所改进,但仍嫌操作繁锁。我们试验了稀土和钍的联合测定的方法,本法将 Rare earth concentrate rare earth determination, the general use of fluoride separation or alkali separation, oxalate gravimetric method. Thorium is determined after the fluorination separation, with hexamethylenetetramine rare earth and thorium separation, and then arsenazo III colorimetric determination of thorium. Operating procedures are very lengthy. Later switched to tributyl phosphate - xylene extraction, arsenazo Ⅲ colorimetric determination of thorium and EDTA complex titration of rare earth, although this method has improved the former method, but is still too complicated to operate. We tested the method of the combined determination of rare earth and thorium, this law will