Method and device for producing sodium nitrate

Abstract

The invention relates to a method and device for producing sodium nitrate. The device comprises a nitrogen oxide ammoxidation preparation system, a soda solution preparation and absorption system, a mother liquor conversion system and a pre-evaporation system. A pre-evaporator is provided with an outer circulating heater. Steam condensate produced by I efficiency of the evaporator is used for heating raw material fluid in the pre-evaporator by virtue of an outer heater, harmful substances such as chloride ion, nitrosyl chloride in the raw material fluid are removed, pre-evaporation pressure is 0.1-0.3MPa, and temperature is 105-125 DEG C. Raw material departing from the pre-evaporator is subjected to evaporation, crystallization, centrifugal separation and drying to prepare a sodium nitrate product. According to the invention, the pre-evaporator provided with the outer circulating heater is used for recycling waste heat of primary steam condensate produced by utilizing I efficiency of the evaporator, energy source is saved and the quality of the sodium nitrate product is improved, corrosion of harmful gas to equipment is eliminated, and service life of the equipment can be beneficially prolonged.

Description

technical field [0001] The invention belongs to the technical field of production of inorganic chemical products, and relates to a method and device for producing sodium nitrate, in particular to the pre-evaporation of raw material liquid and the removal of NaNO by steam condensed water evaporated by the first effect of the evaporator 3 A method and device for improving product quality and saving energy in Cl ions. Background technique [0002] At present, in the process of producing nitrate, evaporation is one of the essential processes. Its main task is to convert the raw material liquid generated by the conversion process, through evaporation and concentration, to make NaNO 3 A state of supersaturation is reached and a qualified solution is prepared for crystallization. In the evaporation process, a large amount of steam condensed water is produced while consuming steam, and the steam condensed water has considerable waste heat. In the prior art, the steam condensed wat...

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Problems solved by technology

[0006] Chloride ions in the raw material liquid not only affect the quality of the product, but the mixture of nitrosyl chloride, chlorine, hydrochloric acid and nitric acid deposits on the welding seam of the equipment to form aqua regia, which will cause serious corrosion to the stainless steel equipment. Once a leak occurs, it is difficult to Re-welding is good, which not only increases the difficulty of equipment maintenance in production, but also reduces the service life of equipment, which becomes a difficult problem for equipment maintenance in the production process of sodium nitrate

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