Gas-phase rectifying method for steam containing ammonia in APT (ammonium paratungstate) production process and equipment

Abstract

The invention discloses a gas-phase rectifying method for steam containing ammonia in the APT (ammonium paratungstate) production process, which is characterized by comprising the following steps of: primary cooling of steam containing ammonia, direct entry of the steam containing ammonia into a condenser on the top of a rectifying tower, gas-phase steamed ammonia cycle of low-concentration ammonia at the bottom of the rectifying tower, and ammonia absorption cycle of an ammonia absorption tower. The invention further provides a set of equipment used for the gas-phase rectifying method. The problems of the difficulty of steam containing ammonia recovery and tail gas treatment in the existing APT production process are solved, and the problems that the concentration of the recovered ammonia is low and the water balance for ammonia reuse of the whole factory cannot be realized are solved by using the gas-phase rectifying method. The gas-phase rectifying method for the steam containing ammonia in the APT production process is invented to increase the concentration of the recovered ammonia and realize the water balance for ammonia reuse of the whole factory, so that all water containing ammonia of the whole factory can be reused, and the ammonia recovery ratio in the APT production process is greatly increased.

Description

technical field [0001] The invention relates to a gas-phase rectification technology for ammonia-containing steam, in particular to a gas-phase rectification method and equipment for ammonia-containing steam in the APT production process. Background technique [0002] In the process of producing ammonium paratungstate (APT) by wet smelting of tungsten, the sodium tungstate solution is transformed into ammonium tungstate solution through extraction, and the ammonium tungstate solution is evaporated and concentrated into ammonium paratungstate product. The production of 1 ton of ammonium paratungstate consumes 0.44 tons of liquid ammonia water, and more than 50% of the ammonia is discharged during the process of evaporation, concentration and crystallization, which is called ammonia-containing steam. The principle of the secondary evaporation crystallization of ammonium tungstate mother liquor is the same as the continuous evaporation crystallization of ammonium tungstate, tha...

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Problems solved by technology

[0010] The present invention aims at the problem of ammonia-containing steam treatment in the existing APT production process, low ammonia gas recovery rate, and low concentration of recycled ammonia water, and invents a g

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