Determination method of sodium oxide content in regenerated sand of sodium silicate sand

Abstract

The invention provides a determination method of sodium oxide content in regenerated sand of sodium silicate sand. The method comprises the steps that: water and a sulfuric acid standard solution are added to scrap-iron-removed regenerated sand; the mixture is continuously heated and stirred for 28-40min under a temperature maintained at 80-90 DEG C; the mixture is cooled to room temperature, and is filtered, such that filter residue and filtrate are obtained; the filter residue is washed by using water, until recovered washing liquid is neutral; the washing liquid is combined with the test solution obtained by filtering; a bromcresol green-methyl red indicating agent is added into the test solution, and the test solution is titrated by using a sodium hydroxide standard solution, until the test solution turns from red to green; the volume of the consumed sodium hydroxide standard solution is recorded; and the sodium oxide content in the regenerated sand is calculated. With the method provided by the invention, the sodium oxide content in the regenerated sand of the sodium silicate sand can be accurately determined, such that an accurate data about whether the regenerated sand can be reused can be provided.

Description

technical field [0001] The invention relates to a method for determining the content of sodium oxide, in particular to a method for determining the content of sodium oxide in regenerated sand of sodium silicate sand. Background technique [0002] The role of molding sand in the casting production process is extremely important, and casting waste products caused by poor quality of molding sand account for about 30-50% of the total casting waste products. Molding sand can be divided into clay sand, sodium silicate sand, cement sand, resin sand, etc. according to the different binders used. The most commonly used one is sodium silicate sand formed by using sodium silicate as a binder. When using sand molds for casting production, 6 to 15 tons of used old sand will be produced for every ton of castings produced. In order to avoid the waste of old sand, the old sand is generally recycled or regenerated and used again. Molding sand with sodium silicate as binder, because the ha...

AI Technical Summary

Problems solved by technology

However, practice has proved that the above method cannot completely dissolve the sodium oxide in the regenerated sand in water, and the liquid material dissolved with sodium oxide is dark brown, which seriously affects the judgment of the titration end point, making the detected sodium oxide content have a large error and reproduces poor sex

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