Method for measuring calcium oxide and magnesium oxide content of tundish covering agent

Abstract

The invention discloses a method for measuring the calcium oxide and magnesium oxide content of a tundish covering agent. The method has the advantages of being higher in speed, accuracy and efficiency. The method comprises the following steps: dissolving a test sample with hydrochloric acid and hydrofluoric acid, adding nitric acid, adding perchloric acid for smoking, adding hydrochloric acid after cooling, and performing heating to dissolve salts; adjusting the pH value to 7 with ammonia water, heating the test solution till the test solution boils, taking down and slightly cooling the test solution, filtering the test solution in a volumetric flask, washing precipitates for 7 to 8 times with a hot ammonium chloride solution, diluting the solution to a scale for volume fixation after cooling, equally dividing the solution into two parts for putting into two beakers; for one of the two breakers, adding small amounts of triethanolamine, water and hydroxylammonium chloride, adding a potassium hydroxide solution to adjust the pH value to 12, adding a proper amount of calcein, and performing titration with an EDTA standard solution until fluorescence green disappears to obtain the amount of calcium; for the other one of the two breakers, adding small amounts of triethanolamine, water and hydroxylammonium chloride, adding an ammonia-ammonium chloride buffer solution to adjust the pH value to 10, taking eriochrome black T as an indicator, and performing titration with the EDTA standard solution until the solution is pure blue to obtain the total amount of calcium and magnesium.

Description

technical field

[0001] The invention relates to the technical field of analysis of novel refractory and thermal insulation materials, in particular to a method for determining the contents of calcium oxide and magnesium oxide in a tundish covering agent. Background technique

[0002] With the continuous development of continuous casting technology, continuous casting has higher and higher requirements on the condition and quality of molten steel. The purity of molten steel is an important indicator to measure the quality of molten steel. There are many factors that affect the purity of molten steel. In addition to being limited by smelting and refining conditions, the pouring conditions of continuous casting are also an important link. Protective pouring, and the protective pouring of molten steel surface in the tundish is the key to prevent secondary pollution of molten steel. In order to prevent secondary oxidation of molten steel and produce high-purity steel, it is not e...

Examples

Embodiment Construction

[0026] The above-mentioned and other technical features and advantages of the present invention will be described in more detail below in conjunction with the embodiments.

[0027] 1. Method summary:

[0028] Use hydrochloric acid (65%), nitric acid (67%)-hydrofluoric acid (40%) to dissolve the sample in a polyethylene plastic beaker, add perchloric acid to smoke, (perchloric acid smoke must be exhausted, otherwise, it will affect For the determination of calcium and magnesium, there is black residue in the sample in the beaker. After the residue treatment, the calcium in the residue is zero. Therefore, it can be said that after a series of acid treatments in the early stage, the calcium and magnesium in the sample have been completely dissolved, so the later stage Calcium can be directly measured, and magnesium does not need to be treated with residue.) Remove it, after cooling, carefully add 5mL hydrochloric acid (65%) along the wall of the cup, and heat to dissolve the salt...

technical field

[0001] The invention relates to the technical field of analysis of novel refractory and thermal insulation materials, in particular to a method for determining the contents of calcium oxide and magnesium oxide in a tundish covering agent. Background technique

[0002] With the continuous development of continuous casting technology, continuous casting has higher and higher requirements on the condition and quality of molten steel. The purity of molten steel is an important indicator to measure the quality of molten steel. There are many factors that affect the purity of molten steel. In addition to being limited by smelting and refining conditions, the pouring conditions of continuous casting are also an important link. Protective pouring, and the protective pouring of molten steel surface in the tundish is the key to prevent secondary pollution of molten steel. In order to prevent secondary oxidation of molten steel and produce high-purity steel, it is not e...

Examples

Embodiment Construction

[0026] The above-mentioned and other technical features and advantages of the present invention will be described in more detail below in conjunction with the embodiments.

[0027] 1. Method summary:

[0028] Use hydrochloric acid (65%), nitric acid (67%)-hydrofluoric acid (40%) to dissolve the sample in a polyethylene plastic beaker, add perchloric acid to smoke, (perchloric acid smoke must be exhausted, otherwise, it will affect For the determination of calcium and magnesium, there is black residue in the sample in the beaker. After the residue treatment, the calcium in the residue is zero. Therefore, it can be said that after a series of acid treatments in the early stage, the calcium and magnesium in the sample have been completely dissolved, so the later stage Calcium can be directly measured, and magnesium does not need to be treated with residue.) Remove it, after cooling, carefully add 5mL hydrochloric acid (65%) along the wall of the cup, and heat to dissolve the salt...

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