Cyclic manufacturing device for coproduction of baking soda and ammonium chloride

Abstract

The invention provides a cyclic manufacturing device for coproduction of baking soda and ammonium chloride. The cyclic manufacturing device comprises a primary-precipitating baking soda device, a coldprecipitation device, a salt precipitation device, a mother liquor cycle device which sequentially communicate, and secondary-precipitating baking soda device, one end of the secondary-precipitatingbaking soda device communicates with the salt precipitation device, and the other end of the secondary-precipitating baking soda device communicates with the mother liquor cycle device. By adopting the cyclic manufacturing device, energy saving and time saving can be achieved during ammonium chloride recovering at the cold precipitation stage, meanwhile, the baking soda and the ammonium chloride can further be produced efficiently, full cycle of motor liquor generated in the manufacturing process in the production process is achieved, the process is easy, and the production cost is low.

Description

technical field [0001] The invention relates to the technical field of chemical production, in particular to a process device for producing sodium bicarbonate (NaHCO3) by double decomposition method, and in particular to a recycling production device for co-production of sodium chloride with sodium chloride. Background technique [0002] In the production process of preparing baking soda and co-producing ammonium chloride by double decomposition method, the separated baking soda mother liquor contains NaCl, NaHCO 3 , NH 4 Cl, wherein sodium bicarbonate is in a saturated state. In the prior art, the mother liquor is directly frozen and added to NaCl for salting out. Sodium bicarbonate is also precipitated together with ammonium chloride due to supersaturation, so that the quality of the ammonium chloride product cannot reach Requirements of national standards (regulation in the national standard of agricultural ammonium chloride of 92 editions: Na in agricultural ammonium ch...

AI Technical Summary

Problems solved by technology

[0002] In the production process of preparing baking soda and co-producing ammonium chloride by double decomposition method, the separated baking soda mother liquor contains NaCl, NaHCO 3 , NH 4 Cl, wherein sodium bicarbonate is in a saturated state. In the prior art, the mother liquor is directly frozen and added to NaCl for salting out. Sodium bicarbonate is also precipitated together with ammonium chloride due to supersaturation, so that the quality of the ammonium chloride product cannot reach Requirements of national standards (regulation in the national standard of agricultural ammonium chloride of 92 editions: Na in agricultural ammonium chloride + content ≤ 1.4%); and the nitrogen content in ammonium chloride products does not reach the national standard of 25%

[0003] However, if the mother liquor is discharged directly, the ammonia nitrogen will seriously pollute the river water source. In order not to discharge waste water, it is often used to recover ammonium chloride and salt by evaporation, but this method has many disadvantages. On the one hand, the mother liquor contains ammonium chloride The total amount of sodium chloride and sodium chloride does not exceed 200g / L, and every ton of ammonium chloride needs to evaporate 5-6 tons of water, and consumes 0.8 tons of coal. In addition, the evaporated salt is difficult to reach industrial-grade standards

These factors make it difficult to industrialize the application of soda by metathesis, poor economical practicability and high process cost

At present, there is no better process device to solve the above problems

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