Salt pan tedding technology of high-magnesium and low-potassium sulfate brine

Abstract

A salt pan tedding technology of high-magnesium and low-potassium sulfate brine comprises the following steps: 1, introducing the high-magnesium and low-potassium sulfate brine into a sodium chloride salt pan, naturally tedding the brine, and introducing the brine into an epsomite salt pan when epsomite in the brine reaches saturation and epsomite precipitates; 2, evaporating the brine, and introducing the brine into first stage carnallite salt pan when the percentage of precipitated epsomite is 40-80 wt%; 3, evaporating the brine, and introducing the brine into a second stage carnallite salt pan when the percentage of precipitated carnallite is 40-60 wt%; 4, continuously evaporating the brine, continuously precipitating the carnallite, and introducing the brine into an old brine salt pan after the brine reaches an old brine point; and 5, crushing first stage carnallite ores, and decomposing and dehalogenating the crushed first stage carnallite ores. The method allows high-quality potassium sulfate to be produced from the high-magnesium and low-potassium sulfate brine which is only used to produce potassium chloride originally, and improves the resource exploitation rate of like salt lakes and underground brine resources and the added values of the product.

Description

technical field [0001] The invention relates to a salt field tanning process of high-magnesium and low-potassium sulfate type brine, belonging to the technical field of salt chemical industry. Background technique [0002] China's sulfate-type potassium salt lakes are rich in soluble potassium salts, which are important raw materials for the production of potassium sulfate. The production of potassium sulfate by using sulfate-type brine is currently realized through the salt field phase separation technology at home and abroad, that is, the process of salt field tanning. The salt field phase separation technology uses solar radiation as the energy source. In a large area pool with a specific structure, brine is stored at an appropriate depth. During the process of absorbing solar energy, due to the thermochemical energy storage effect of the salt solution, the temperature rises, which is beneficial to The water evaporates, and the brine concentrates until a certain salt rea...

AI Technical Summary

Problems solved by technology

Therefore, in the salt field process of the entire evaporation route, if the salt field classification mode and subsequent processing technology adopted in the prior art are followed, the potassium-magnesium mixture required for the production of potassium sulfate cannot be obtained under the condition that potassium chloride is not precipitated. salt; and in the case of a small amount of potassium chloride precipitation, in order to ensure the content of potassium ions in the mixed salt, the output of the qualified grade potassium-magnesium mixed salt obtained is very low, which cannot be matched with the amount of carnallite in the latter stage

In the absence of potassium-magnesium mixed salt or the output cannot match the carnallite ore, according to the existing technical scheme, the high-magnesium and low-potassium sulfate type brine cannot directly produce potassium sulfate products or only produce a very small amount of potassium sulfate products. This in turn leads to excess carnallite resources, and brine resources cannot produce products with high added value

The current solution is generally to use this type of salt lake brine to directly produce potassium chloride with lower value

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