Slurry-process ammonium phosphate neutralization reaction system

Abstract

The invention discloses a slurry-process ammonium phosphate neutralization reaction system, which comprises a neutralization tank, a sealing intercepting device, a first-effect flashing chamber and asecond-effect flashing chamber. The sealing intercepting device comprises a filtering outer cylinder, the upper end of which is provided with a sealing flange and the bottom surface of which is provided with a slag discharge port. The slag discharge port is connected to a slag discharge valve. The filtering outer cylinder sleeves a filtering inner cylinder, the bottom of which is communicated withthe slag discharge port and the top of which is contacted with the sealing flange. Liquid permeable holes are distributed on the sidewall of the filtering inner cylinder. The upper part of the filtering outer cylinder is provided with a feed pipe, which extends into the upper part of the filtering inner cylinder. The lower end of the filtering outer cylinder is provided with a discharge pipe. A pusher plate is also disposed in the filtering inner cylinder. The upper side of the pusher plate is connected with a push rod, which extends from the center hole of the sealing flange to the outside of the filtering inner cylinder. A sealing device is arranged at the center hole of the sealing flange. The push rod passes through a packing gland at the top of the sealing device to be connected to apiston rod of a cylinder positioned above the filtering outer cylinder. By the system, the influence on the operating environment is reduced, and work efficiency is improved.

Description

technical field [0001] The invention relates to a slurry method ammonium phosphate neutralization reaction system, which belongs to the technical field of fertilizer production technology. Background technique [0002] Slurry ammonium phosphate concentrates the slurry after the neutralization reaction of wet-process phosphoric acid and ammonia. It is a new process specially developed for medium and low-grade phosphate rock. The process is to use P 2 o 5 About 18% to 30% of dilute phosphoric acid reacts with ammonia, and the required monoammonium phosphate slurry is obtained by controlling the degree of neutralization. After pressure spray drying, the monoammonium phosphate product is obtained. Since the requirements for phosphoric acid are not too strict, dilute phosphoric acid produced by wet method, press filter residue of fine phosphate, concentrated phosphoric acid sludge from diammonium phosphate production can be used, and it is also allowed to add ore pulp to adjus...

AI Technical Summary

Problems solved by technology

[0006] 1) Trough type neutralization process: the reaction tank is open, pollutes the environment, the heat source is not used, the process is long, and there are dynamic equipment such as stirring and delivery pumps that consume high energy

[0007] 2) Tubular neutralization process: the requirement for phosphoric acid is high, and the acid with a lot of impurities will cause fouling to block the nozzle, making the production and cleaning work heavy

[0008] 3) Outer circulation ammoniation process: the reaction time is short, and impurities can easily cause fouling of subsequent equipment; there are circulating pumps and other moving equipment; solid debris is difficult to intercept, and solid debris will be brought into the next process to cause blockage of heater tubes

[0009] 4) Neutralization and concentration integration process: neutralization reaction heat increases the amount of cooling water, which is not energy-saving; it is difficult to intercept solid impurities; when impurity salts precipitate, there is not enough time to completely eliminate supersaturation in the flash chamber before entering the heating pipe, which will intensify The heater tubes are blocked, shortening the cleaning cycle of the concentration system

[0010] 5) Forced circulation neutralization process: it occupies a large area and has a circulating pump for moving equipment; it is difficult to intercept solid debris

[0013] The traditional tank-type neutralization reactor uses an open filter screen to intercept solid impurities, and it is easy to clean up the slag. However, since the neutralization reaction is a strong exothermic reaction, the hot slurry has a large amount of steam, which will cause The pollution of the surrounding environment and the visual pollution of the steam, so the process has been changed to a closed filter device with pressure, and the slag discharge is carried out by manual pressure relief after regular parking, which not only causes production interruption, but also has high labor intensity and very troublesome operation

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