Process for the recovery of iodine

Abstract

The invention aims at providing a process for the recovery of iodine which can be easily and economically carried out without premixing an iodine compound with an alkali metal compound and a solvent prior to the introduction into a combustion furnace. The aim is attained by a process for the recovery of iodine which is characterized by feeding separately an iodine-containing solution containing iodine and / or an iodine compound and a basic alkali metal compound solution and / or a basic alkaline earth metal compound solution into a roasting furnace to conduct oxidative decomposition of combustibles through heat treatment and fix iodine as stable salts and making the iodine and / or iodine salts contained in the effluent from the heat treatment step absorbed in water or an aqueous solution

Description

technical field [0001] The present invention relates to the method for reclaiming iodine, regardless of whether the method is respectively recovered into an iodine-containing solution containing iodine and / or an iodine compound (also referred to as an iodine-containing solution containing iodine solution) to recover iodine easily and economically by direct heat treatment with a roasting furnace. Background technique [0002] Iodine is used as X-ray contrast agents, medicines, fungicides and antifungal agents as raw materials for daily life; as catalytic stabilizers for industrial use, raw materials for photographs; as feed additives and herbicides for agricultural use, etc. resource. In addition, in recent years, it has become an extremely important resource indispensable to major industries in our country, such as being used in the production stage of liquid crystal films. But, among the countries that mine iodine in the world, my country (concentrated in Kanto, output ac...

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Problems solved by technology

In addition, there is also the following problem: In order to mix the iodine-containing substance containing iodine or an iodine compound, the alkali metal compound, and the solvent to the set pH value while finely adjusting each input amount, it is necessary to have a flow rate adjustment mechanism and a pH value adjustment mechanism. Complicated and advanced mixing and stirring device with structure etc.

In addition, in order to perform continuous processing, it is also necessary to have a plurality of such mixing devices, which requires further complexity and high-level

In addition, there is no solvent suitable for both waste liquid and waste oil containing iodine or iodine compounds, and it is extremely difficult to dissolve alkali metal compounds uniformly in both. The problem of reaction efficiency and thus lower recovery rate

In addition, if more iodine is sublimated, it will impose a burden on the absorption tower in the subsequent process.

Therefore, existing equipment cannot cope with it, and if it is left unattended, iodine will be released into the atmosphere, which may cause environmental pollution

In addition, in order to withstand a large load, it is necessary to install a large absorption tower, which is not economical.

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