Production method of heavy soda ash

Abstract

The invention discloses a production method of heavy soda ash. The production method comprises the following steps: adding light soda ash and a sodium carbonate saturated solution into a hydration crystallizer; introducing crystal mush into a thickener to adjust the solid-to-liquid ratio after the reaction, separating the crystal mush in the thickener in a centrifugal machine, and introducing thesupernatant of the thickener into a mother liquor barrel; separating, washing with washing water, removing salt and impurities on the surface of crystal mush, and feeding centrifugate into the motherliquor barrel; treating the centrifuged solid to obtain a heavy soda ash product; evaporating the 20-50% mother liquor until the common saturation point of sodium carbonate and sodium chloride is reached to separate out sodium carbonate monohydrate crystals, mixing the sodium carbonate monohydrate crystals and steam condensate, recycling the mixture into a hydration crystallizer, and feeding the residual sodium chloride and sodium carbonate co-saturated solution into a combined-soda system vacuum salt making device; enabling 50-80% mother liquor to enter a clarification device, adding sodium sulfide, removing iron impurities, and enabling clarified liquor to enter a hydration crystallizer to continue to prepare heavy soda ash. According to the method, sodium chloride and iron impurities inthe sodium bicarbonate mother liquor in the current sodium bicarbonate production process can be removed, discharge of the sodium bicarbonate mother liquor is reduced, and the quality of the sodium bicarbonate product is improved.

Description

technical field [0001] The present invention relates to a kind of production method of soda ash, more specifically, relate to a kind of production method of heavy soda ash. Background technique [0002] In the patent CN02148849.5 "A Production Method of Heavy Soda Ash", light soda ash and saturated sodium carbonate solution are used as the main raw materials, and the hydration reaction is carried out in a hydration crystallizer according to a certain ratio for 5-10 minutes. The slurry is sent to the thickener to thicken, and the thick crystal slurry enters the centrifuge for separation. During the separation process, washing water is used to remove the salt and impurities on the solid surface. The washed solid is sent to the heavy soda ash calciner, and is screened, Heavy soda ash is obtained after cooling. The heavy soda ash product prepared by this method has a uniform particle size and is not suitable for scabbing. However, with the long-term production operation, impurit...

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Problems solved by technology

[0002] In the patent CN02148849.5 "A Production Method of Heavy Soda Ash", light soda ash and saturated sodium carbonate solution are used as the main raw materials, and the hydration reaction is carried out in a hydration crystallizer according to a certain ratio for 5-10 minutes. The slurry is sent to the thickener to thicken, and the thick crystal slurry enters the centrifuge for separation. During the separation process, washing water is used to remove the salt and impurities on the solid surface. The washed solid is sent to the heavy soda ash calciner, and is screened, Heavy soda ash is obtained after cooling. The heavy soda ash product prepared by this method has a uniform particle size and is not suitable for scabbing. However, with the long-term production operation, impurities such as sodium chloride and iron in the heavy soda ash mother liquor will gradually increase with the recycling of the mother liquor. Accumulation, in order to obtain qualified products, the mother liquor needs to be discharged regularly

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