A kind of production method of potassium nitrate for optical glass

Abstract

The invention discloses a method for producing potassium nitrate for optical glass. The method comprises the steps of preparing raw materials, cooling and crystallizing to prepare potassium nitrate semi-finished product crystal, washing the potassium nitrate semi-finished product crystal, thermally dissolving to recrystallize, filtering, and dehydrating and drying a finished product, wherein a rigidity functional agent is added in the thermal dissolving and recrystallizing process, and includes silicic acid or potassium metaaluminate and silicic acid. According to the method, a special purification process technology is adopted based on an existing potassium nitrate production process, the potassium nitrate prepared by the method has high purity, the preparation process is simple, energy consumption is less, and the production cost is low.

Description

technical field [0001] The invention relates to a production method of potassium nitrate for optical glass. Background technique [0002] Nowadays, more and more glass products use chemical tempering to improve the strength of glass. The principle of chemical tempering to improve strength is to place the glass or glass products to be tempered in molten potassium nitrate molten salt for a certain period of time, and through the replacement reaction between potassium ions in the molten potassium nitrate salt and sodium ions in the glass, due to the diameter of the potassium ions It is larger than sodium ions, thereby forming compressive stress on the glass surface to achieve the purpose of improving the strength of the glass. Practice shows that the chemical tempering effect of glass has a high requirement on the purity of potassium nitrate, and the higher the purity of potassium nitrate, the higher the stress on the glass surface and the better the tempering effect. Due to ...

AI Technical Summary

Problems solved by technology

Due to the existing method for preparing potassium nitrate, its potassium nitrate includes many sources of impurities such as organic residues, and the degree of purification is limited. Even if methods such as including purifying agents are adopted, it is difficult to meet the requirements for the use of tempered glass, and too much purifying agent will make the solution turbid. , the small amount of addition will affect the effect of impurity removal. In addition, potassium chloride, one of the main raw materials, generally contains a very small amount of flotation agent, etc., which are mostly organic impurities, which makes high-purity glass potassium nitrate often not clear enough after melting, which affects the strengthening effect.

[0003] In this regard, the prior art adopts reheating and repurifying the finished potassium nitrate, and then cooling, which not only increases energy consumption, but also is extremely uneconomical, and the purification effect is not ideal due to the defects of its purification method.

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