System and method for producing optical glass grade potassium nitrate from sodium nitrate high-temperature mother liquor

Abstract

The invention relates to the technical field of potassium nitrate production systems and methods, and concretely relates to a system and a method for producing optical glass grade potassium nitrate from a sodium nitrate high-temperature mother liquor. The system comprises a batching tank, a plate-and-frame filter press, a vacuum crystallizer, a first filtering and washing device, a dissolving tank, a cooling crystallizer, a second filtering and washing device, a first two-stage material pushing centrifuge, a second two-stage material pushing centrifuge, a fluidized bed drying machine and a two-effect evaporator. Aqueous solutions generated in all production processes can be fully recycled, so the total yield of potassium ions is 95% or higher, the total yield of nitrate ions is 98% or above, no wastewater is discharged, and the water consumption is greatly reduced; and the principle that the solubility of potassium nitrate is greatly influenced by temperature and the solubility of other miscellaneous salts (sodium chloride, sodium sulfate and the like) is slightly influenced by temperature is used to crystallize and wash potassium nitrate twice respectively, so impurity ions in potassium nitrate crystals can be effectively removed, and the optical glass grade potassium nitrate with the purity of 99.9% or above is obtained.

Description

technical field [0001] The invention relates to the technical field of potassium nitrate production systems and methods, and relates to a system and method for producing glass-grade potassium nitrate by using high-temperature sodium nitrate mother liquor. Background technique [0002] Optical glass grade potassium nitrate is mainly used to strengthen touch screen (mobile phone, computer, cash machine, etc.) glass (thickness less than 0.7mm). Stress, so that the strength of the glass is increased, so that it is not easy to break and easy to process. At present, there are few enterprises that can produce optical glass-grade potassium nitrate. The main reason is that optical glass-grade potassium nitrate requires high purity, impurity content is required to reach ppm level, and impurities harmful to human body are even required to reach ppb level. , production environment, etc. have stricter requirements. [0003] At present, there are mainly two mainstream production process...

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Problems solved by technology

[0004] The present invention provides a system and method for producing glass-grade potassium nitrate by using sodium nitrate high-temperature mother liquor, which overcomes the above-mentioned deficiencies in the prior art, and can effectively solve the common problem of high energy consumption in the existing production process of glass-grade potassium nitrate , high water consumption, pollution, low raw material yield and product qualification rate, and inconvenient control

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