Method for producing iodine product through electronic control ionic membrane extraction coupling electrolysis process

Abstract

The invention discloses a method for producing an iodine product through an electronic control ionic membrane extraction coupling electrolysis process. The method comprises the steps of putting a polypyrrole functional membrane material with adsorption selectivity into a raw material liquid containing iodide ions, applying a corresponding oxidation potential to the membrane material, and adsorbingthe iodide ions in a water phase into the membrane material, so that the iodide ions are enriched; after the enrichment reaches saturation, applying an opposite potential, and desorbing the iodide ions adsorbed in the membrane into a corresponding salt solution under an electric field auxiliary action, so that the membrane material is regenerated; and carrying out specific oxidation reaction on acounter electrode, and generating the corresponding iodine product. According to the method provided by the invention, electrode potential oxidoreduction is adopted as the main driving force, so thatthe secondary pollution caused by a chemical regenerating agent is eliminated; by adopting electrode potential oxidoreduction as the driving force, the adsorption and desorption efficiency of the ions is greatly improved, and the iodide ions in the low-concentration raw material liquid containing iodine can be extracted; and the functional membrane material can be recycled.

Description

Technical field [0001] The invention relates to a method for producing iodine products by an electronically controlled ion membrane extraction coupled electrolysis method, and specifically relates to an electronically controlled ion membrane extraction coupled electrolysis method for extracting iodine ions in salt field brine, oil and gas field brine and other raw material liquids, and extracting The method of converting iodide ions into corresponding iodine products. It belongs to the field of iodine production. Background technique [0002] my country mainly relies on extracting iodine from marine algae plants. In addition, it also recovers iodine from wet-process phosphoric acid produced by decomposing phosphate rock with sulfuric acid. The annual output is about 600 tons, accounting for only 2.14% of the total global iodine output. With the development of the economy, China's demand for iodine resources has also increased. However, due to technological limitations, the outpu...

AI Technical Summary

Problems solved by technology

With the development of the economy, China's demand for iodine resources has also increased. However, limited by technology, iodine production is very low and the cost is high, so it needs to be imported in large quantities from abroad every year.

[0003] my country is a large ocean country. At present, the output of sea salt reaches 18 million tons per year, and the annual by-product brine is 15 million m 3 Each chemical ion in brine has been concentrated hundreds of times compared with seawater, and it is an effective raw material for extracting iodine products. However, due to economic and technological limitations, its utilization rate is less than 20%, and most of it is re-discharged into the ocean or salt pans for circulation, which not only causes A serious waste of resources and damage to the ecological balance of the ocean

After the activated carbon adsorption method absorbs iodine, analysis and other operations are required, the steps are cumbersome and the cost is high [Inorganic chemicals industry, 2010, 42 (10): 54-55.]

The precipitation method mainly uses iodide ions and copper ions or silver ions to form insoluble precipitates, and then separates them by filtration. The process of this method is relatively complicated, the input of chemicals is large, the scale of engineering equipment is large, and the cost is high [J Hazard Mater, 2013, 246(4), 199-205; Langmuir, 2000, 16, 4519-4527.]

The air blowing method is one of the main methods for producing iodine in industry at present. It is a key step to oxidize iodide ions to generate elemental iodine with chlorine gas, but a slight excess of chlorine gas can easily make iodine generate iodate, that is, peroxidation

The ion exchange method is suitable for extracting iodine from low-concentration raw material liquid. Ion exchange resin has selective adsorption and is easy to increase the concentration of iodine, but its anti-interference ability is poor, and it is easily interfered by other impurity ions in the raw material liquid, resulting in poisoning. Repeated use will reduce the effect [Chemistry, 1995, (1): 28-30.]

The electrolysis method mainly uses the potential jump to control the oxidation degree of iodine, and uses the electrode reaction to oxidize iodide ions into iodine element, which is enriched on the electrode surface, but its output is limited

Images