Method for determining content of niobium, silicon and phosphorus in ferromanganese niobium

Abstract

The invention provides a method for determining the content of niobium, silicon and phosphorus in ferromanganese niobium. The method comprises steps that mixed acid, nitric acid and hydrofluoric acidare sequentially added to a ferromanganese niobium sample, after the ferromanganese niobium sample is completely dissolved, the dissolved sample solution is placed in a volumetric flask to prepare thetest solution of to-be-tested elements, the mixed acid is prepared from aqua regia and the dilute sulfuric acid at a volume ratio of 4-7.5:1, a matrix mother solution and a standard solution of the to-be-tested elements are prepared; the content of the to-be-tested elements in the ferromanganese niobium is determined according to the test solution of the to-be-tested elements, the matrix mother solution and the standard solution of the to-be-tested elements; the to-be-tested elements are at least one of niobium, silicon and phosphorus.

Description

technical field [0001] The invention belongs to the field of alloy detection and analysis, and in particular relates to a method for determining the contents of niobium, silicon and phosphorus in ferro-niobium manganese. Background technique [0002] The content of niobium, silicon and phosphorus in niobium manganese ferroalloy is an important index to measure the quality of niobium manganese ferroalloy. In the process of determining the content of niobium, silicon and phosphorus in niobium manganese ferromanganese, due to the high chemical stability of niobium element, it can only react with hydrofluoric acid in inorganic acid, and it is often necessary to add hydrogen to determine the content of niobium element in the alloy. Hydrofluoric acid is used to decompose the sample, and hydrofluoric acid needs to be added under heating conditions, and the temperature can easily exceed 80°C. At this time, the silicon element in ferroniobium manganese can easily react with hydrofluo...

AI Technical Summary

Problems solved by technology

In the process of determining the content of niobium, silicon and phosphorus in niobium manganese ferromanganese, due to the high chemical stability of niobium element, it can only react with hydrofluoric acid in inorganic acid, and it is often necessary to add hydrogen to determine the content of niobium element in the alloy. Hydrofluoric acid is used to decompose the sample, and hydrofluoric acid needs to be added under heating conditions, and the temperature can easily exceed 80°C. At this time, the silicon element in ferroniobium manganese can easily react with hydrofluoric acid to form SiF 4 , SiF 4 As a volatile substance, it will cause the volatilization loss of silicon element, which makes it impossible to accurately measure the silicon content; at present, by adding hydrofluoric acid at room temperature, the complexation of hydrofluoric acid and niobium is guaranteed without volatilization loss of silicon, however For niobium manganese ferromanganese, the content of manganese (manganese carbide) is relatively high, and the sample needs to be heated and smoked by oxidizing acid before it can be completely decomposed. If it is heated and smoked, the silicon element will be volatilized and lost, and silicon cannot be accurately measured. Smoke from heating, incomplete decomposition of manganese carbide in the sample, unable to accurately determine the technical problem of manganese

[0003] After searching, some literatures have proposed to use HNO at room temperature or at a temperature of 60°C 3 and HF to dissolve ferroniobium samples, but this method cannot decompose the carbides in samples with high manganese content

Some literatures have proposed that the sample should be decomposed with nitric acid, hydrofluoric acid, sulfuric acid or perchloric acid to decompose the ferromanganese sample, but this method will cause the loss of silicon in the sample, and the silicon content cannot be accurately determined

Some literatures propose to use anhydrous sodium carbonate, sodium peroxide and other alkali fusion methods to decompose ferromanganese samples, but this method contains too much salt and cannot measure low-level phosphorus.

Therefore, for the determination of the content of niobium, silicon and phosphorus in ferroniobium manganese, two or even three times of dissolution and determination are required, which greatly wastes manpower and material resources, and is not suitable for rapid determination.

In addition, the determination of high niobium content is usually carried out by tannic acid hydrolysis gravimetric method. This method requires a series of complicated steps such as precipitation, filtration, and burning. It uses many chemical reagents and is not suitable for high-efficiency analysis and detection.

There is also a literature report on the method of using inductively coupled plasma emission spectrometry to measure high-content niobium. In the process of determination, due to the high content of niobium, the precision of instrumentation is poor, and it needs to be diluted for measurement. The content of phosphorus is low. After dilution, the spectral intensity of phosphorus element is very low, which will lead to inaccurate measurement of phosphorus content.

[0004] Therefore, there is an urgent need for a method in this area to solve the problem that the content of niobium, silicon and phosphorus in ferroniobium manganese can not be quickly and accurately measured at the same time

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