Apparatus for recycling iodine from diluted phosphoric acid for phosphoric acid manufacture with wet-process

Abstract

The invention discloses a device for recovering iodine from dilute phosphoric acid in phosphoric acid production with a wet method, comprising a pipeline (1) for leading in the dilute phosphoric acid; the pipeline (1) is connected with an oxidation tank (3), the oxidation tank (3) is connected to a shower (4) above an extracting tower (2) by the pipeline, the lower part of the extracting tower (2) is connected with a blast blower (10), an air outlet (5) of the extracting tower (2) is connected with a packing absorbing column (6), an absorption liquid pipeline (7) of the packing absorbing column (6) is connected with a receiving tank (8) which is connected with an iodine separating tank (9). Proved by a series of industrial tests and researches conducted by the applicant in a phosphorus chemical factory, the device of the invention can realize mass industrial production for extracting iodine, and the device is obtained by optimization through a plurality of tests.

Description

technical field [0001] The invention relates to a device for recovering iodine from dilute phosphoric acid produced by wet-process phosphoric acid, especially a device for extracting iodine from dilute phosphoric acid with a concentration of 20-25% used in the process of producing phosphorus products using iodine-containing phosphate ore as raw material; It belongs to the field of environmental protection and chemical technology Background technique [0002] At present, most of the industrial iodine manufacturers in my country use high-grade iodide-containing brine, brine, or kelp soaking solution (iodine content: 200-300mg / l) as raw materials to produce industrial iodine. Most of the adopted processes are ion exchange resin methods. That is to say, the high-grade iodide-containing bittern, brine, or kelp soaking liquid is acidified with acid, and chlorine gas is introduced to make iodine free and precipitate, and then adsorbed by polystyrene ion exchange resin. There are tw...

AI Technical Summary

Problems solved by technology

There are two major problems in this method: the one is that the production operation cost is high, and the 2nd, the production process requires high iodine content to raw materials (brine containing iodide, brine, or kelp soaking liquid)

my country's Sichuan Zigong Salt Industry Company had an iodine production plant that used the blow-out method, but the production was stopped because the iodine content of the raw material solution was lower than 200mg / l and the production cost was high.

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