Method for measuring metallic magnesium content of briquette nodulizing agent by using complexometry

Abstract

The invention discloses a method for measuring the metallic magnesium content of a briquette nodulizing agent by using complexometry. The method comprises the steps of dissolving metallic magnesium in a test sample in dilute acetic acid, removing other Insoluble matters through filtering and washing, and fixing the volume of the filtrate in a volumetric flask; and weighing a certain volume of filtrate, regulating the pH value to 6-7 with ammonia water, separating interference elements with a copper reagent, complexing calcium with EGTA (ethylene glycol tetraacetic acid) when the pH is 10, and performing complexometry on magnesium by using EDTA (ethylene diamine tetraacetic acid), wherein eriochrome black T is an indicator. The method can detect that the metallic magnesium content in a briquette nodulizing agent sample is 5-15%, which nearly covers the metallic magnesium distribution gradients of all nodulizing agents in the production process, and can be applied to quantitative detection of the metallic magnesium in the laboratory briquette nodulizing agent for a long term. The method has the advantages of simplicity, fastness, high accuracy and precision and the like.

Description

technical field [0001] The invention relates to a method for chemically analyzing metallurgical raw materials, in particular to a method for measuring the content of metal magnesium in a low-silicon briquetting nodulizer. Background technique [0002] The low-silicon briquette spheroidizer is composed of magnesium powder, iron powder and the designed silicon content, and then directly pressed under high pressure to form, which contains 5% ~ 15% Mg, ≤ 5% C, ≤ 20% Si, and can also be According to the need, add the components that are beneficial to the spheroidization of graphite, such as rare earth, recarburizer, etc. After the metal magnesium in the nodulizer enters the molten iron, it first acts as a desulfurizer and deoxidizer. When the sulfur in the molten iron drops to a certain value, the magnesium metal starts to spheroidize the graphite, making the graphite grow into a spherical shape. Therefore, fully understanding the content of metal magnesium in the low-silicon br...

AI Technical Summary

Problems solved by technology

Because the low-silicon briquette spheroidizer contains large particles and strong ductility magnesium powder and iron powder, its uniformity is poor, and the metal magnesium powder has high activity, so it is not suitable for direct crushing or grinding according to the alloy sample preparation method. The sample can eliminate the error caused by poor uniformity by taking a large number of samples

If a large number of samples are completely dissolved, a large amount of strong acid is required to dissolve completely, but a large amount of carbon in the sample is difficult to be destroyed, floating in the test solution, and needs to be filtered, and there are a lot of iron ions in the solution, which will affect the metal. The complexometric titration of magnesium results in long analysis time, complicated analysis steps, and the general level of repeatability is about 3%. In order to meet the requirements of fast and accurate sample analysis on site, it is necessary to invent a low-silicon briquette spheroidizer The method of metal magnesium content in

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