A kind of method that recovers elemental iodine from zinc iodide waste salt

A zinc iodide and iodine recovery technology, applied in the direction of iodine/hydrogen iodide, iodine, etc., can solve the problems of high product disposal and recovery costs, low purity of iodine element, and difficult separation of iodine element, so as to reduce corrosion and reaction Fast and thorough, shortened time results

Active Publication Date: 2022-05-10
PERIC SPECIAL GASES CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] Most of the current technology is to make iodine-containing salt into an aqueous solution and then extract iodine from it. The obtained crude iodine still needs to be further separated from solvent or water vapor, etc., and the preparation process is long; in addition, the aqueous solution containing iodine ions is highly corrosive, which makes the equipment easy to corrode. The 3rd, the iodine elemental substance that reclaims to obtain exists water, and the moisture in the iodine elemental substance is difficult to separate, causes the iodine elemental purity not high; The 4th, the oxidant (Cl 2 、KIO 3 、K 2 Cr 2 o 7 etc.) and solvent (CCl 4 etc.) Product disposal and recycling costs are high

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] (1) Pretreatment of zinc iodide waste salt: In the case of nitrogen gas, heat 100g of zinc iodide waste salt to 280°C, the moisture and organic matter in the zinc iodide waste salt will be taken out with the carrier gas to form Tail gas, when the moisture content in the tail gas is less than 10ppm, the pretreatment ends;

[0036] (2) In the case of feeding nitrogen, add the pretreated zinc iodide waste salt into the reactor and heat it to 450°C, and feed oxygen, wherein the mass space velocity of nitrogen relative to the zinc iodide waste salt is 1h -1 , the volume ratio of oxygen and nitrogen is 1:20, and when the ratio of the amount of oxygen-introduced substance to that of zinc iodide reaches 5:1, the reaction is terminated to obtain tail gas, which is sequentially heated at 220°C and 150°C Condensation at 80° C. and 30° C. for 5 minutes respectively to cool the elemental iodine respectively for 5 minutes to condense and precipitate impurities; to obtain 74.17 g of r...

Embodiment 2

[0038] (1) Pretreatment of zinc iodide waste salt: In the case of feeding nitrogen, heat 100g of zinc iodide waste salt to 300°C, the moisture and organic matter in the zinc iodide waste salt will be taken out with the carrier gas to form Tail gas, when the moisture content in the tail gas is less than 10ppm, the pretreatment ends;

[0039] (2) In the case of feeding nitrogen, add the pretreated zinc iodide waste salt into the reactor and heat it to 420°C, and then feed air, wherein the mass space velocity of nitrogen relative to the zinc iodide waste salt is 1.1 h -1 , the volume ratio of air and nitrogen is 1:10, and when the ratio of the amount of the substance introduced into the air to the substance of zinc iodide is 10:1, the reaction is terminated to obtain tail gas, and the tail gas is sequentially heated at temperatures of 350°C and 320°C Condensate for 10 minutes to condense and precipitate impurities; then cool at 80°C and 20°C for 2 minutes to cool iodine, and obt...

Embodiment 3

[0041] (1) Pretreatment of zinc iodide waste salt: In the case of feeding nitrogen and argon, heat 100g of zinc iodide waste salt to 200°C, wherein the volume ratio of nitrogen and argon is 1:1, iodide The moisture and organic matter in the zinc waste salt will be taken out with the carrier gas to form tail gas. When the moisture content in the tail gas is less than 10ppm, the pretreatment is over;

[0042] (2) In the case of feeding argon, the pretreated zinc iodide waste salt is added to the reactor and heated to 480° C., and ozone is fed, wherein the mass space velocity of argon relative to the zinc iodide waste salt is 0.1h -1 , the volume ratio of ozone and argon is 1:50, when the ratio of the amount of the substance that is introduced into the ozone to the amount of the zinc iodide is 2:1, the reaction is completed and the tail gas is obtained. , 250°C, 200°C and 150°C were condensed for 2 minutes to condense and precipitate impurities, and then respectively cooled at 1...

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Abstract

The invention relates to a method for recovering elemental iodine from zinc iodide waste salt, belonging to the fields of fine chemical industry and environmental protection. The method includes: pretreatment of zinc iodide waste salt: heating the zinc iodide waste salt to 200-300°C under the condition of feeding carrier gas, the moisture and organic matter in the zinc iodide waste salt will Take out to form tail gas, and end when the moisture content in the tail gas is less than 10ppm; then, in the case of feeding the carrier gas, heat the pretreated zinc iodide waste salt to 300-600 °C, feed the oxidant, and reduce the The iodine element and impurities are brought out with the carrier gas to form tail gas. The tail gas is cooled at a temperature of 390-150°C according to more than two temperature intervals to condense and precipitate impurities. The cooling time of each temperature interval is 2-15min, and then Cool at a temperature of 110-5°C to obtain simple iodine. The method has the advantages of short preparation process, low cost and high purity of iodine simple substance obtained.

Description

technical field [0001] The invention relates to a method for recovering elemental iodine from zinc iodide waste salt, belonging to the fields of fine chemical industry and environmental protection. Background technique [0002] Zinc iodide waste salt is a by-product of fine chemical production. Zinc iodide waste salt generally contains water and organic matter such as dichloromethane and isopropyl ether. At present, iodine is a scarce resource in the world, so the recovery and reuse of iodine has become an effective means of saving resources. [0003] Most of the current technologies are to make iodine-containing salt into an aqueous solution and then get iodine from it. The recovery methods include ion exchange, air blowing, extraction and other methods. [0004] Ion exchange method is the most commonly used enrichment method; this method requires acidification-oxidation-alkali washing-separation-refining and other steps; Yang Jianyuan et al. used 717 anion exchange resin ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B7/14
CPCC01B7/14
Inventor 郗少杰姚刚张浩郭君张龙吴昊俣张子雨徐海云
Owner PERIC SPECIAL GASES CO LTD
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