Determination method of phosphorus content in niobium-containing steel

Abstract

The invention provides a determination method for the content of phosphorus in niobium-containing steel. The method comprises the following steps: carrying out acidolysis on the niobium-containing steel; adding perchloric acid and heating until smoke is formed; adding hydrochloric acid and hydrogen bromide; heating again until the smoke is formed; adding a sodium chromate solution and a sodium sulfite solution in sequence, heating to boiling and then cooling; adding a sodium hydroxide solution and filtering to obtain a mother solution; taking the mother solution and adding perchloric acid until the mother solution is acidic; then adding a bismuth salt solution and an ammonium molybdate tetrahydrate mixed solution to generate a phosphorus-bismuth-molybdenum heteropolyacid complex; adding ascorbic acid to a mixed solution composed of the mother solution, the bismuth salt solution and the ammonium molybdate tetrahydrate mixed solution to reduce the phosphorus-bismuth-molybdenum heteropolyacid complex to bismuth-phosphorus-molybdenum blue to obtain a solution to be detected; and measuring the absorbance of the bismuth-phosphorus-molybdenum blue in the solution to be detected by a spectrophotometric method and calculating to obtain the content of phosphorus in the niobium-containing steel. The determination method has the beneficial effects that no toxic organic reagent is used in the detection process and extraction is not carried out; the operation is simple; and the content of phosphorus in the niobium-containing steel can be accurately determined.

Description

technical field [0001] The invention relates to the technical field of chemical analysis of niobium-containing steel, in particular to a method capable of measuring the phosphorus content in niobium-containing steel. Background technique [0002] The existing phosphorus-molybdenum blue photometric method or bismuth-phosphorus-molybdenum blue photometric method for determining the phosphorus content of niobium-containing steel all use toxic chloroform to extract and separate niobium, and then extract with butyl acetate or n-butanol. The method is cumbersome to operate and uses toxic and harmful organic reagents, which not only threatens the physical and mental health of operators, but also seriously pollutes the environment. [0003] Therefore, it is very necessary to invent a bismuth-phosphorus-molybdenum blue-blue photometric method that does not use organic reagent extraction, is easy to operate and can accurately determine the phosphorus content in niobium-containing stee...

AI Technical Summary

Problems solved by technology

The method is cumbersome to operate and uses toxic and harmful organic reagents, which not only threatens the physical and mental health of operators, but also seriously pollutes the environment

Images