Determination of RE Content in Phosphate Ores Bearing Rare Earth with Azo Reagents

Rare earth in phosphate rock is measured by spectrophotometric analysis,using arsenazo Ⅲ and chlorophosphonazo Ⅲ as chromogenic agent,respectively.It is shown through the experimental results that chlorophosphonazo Ⅲ reagent is superior to arsenazo Ⅲ,and it has ability to adapt to a wide range of acidity,strong anti-interference ability of impurities.L.Beer's law is obeyed in the range of 0μg/mL~ 50μg/mL of rare earth concentration and the recovery of standard addition shows that the method is accurate and reliable.