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CN-122010172-A - Chlorination purification method for separating and recycling chromium, nickel and manganese impurities in zirconium material

CN122010172ACN 122010172 ACN122010172 ACN 122010172ACN-122010172-A

Abstract

S1, uniformly mixing zirconium material containing impurities with a carbonaceous reducing agent according to a proportion, placing the mixed material into a reaction device, introducing chlorine at a set temperature for chlorination reaction to generate a crude ZrCl 4 gaseous mixture; S2, conveying the crude ZrCl 4 gaseous mixture generated by the reaction into a gas phase conveying pipeline of a pre-condenser for pre-cooling to enable the main impurity chloride to be condensed and separated out preferentially, and S3, introducing the pre-cooled gas phase product into a main condenser for fractional condensation, so that efficient and stable removal of impurities and directional recovery of high-purity ZrCl 4 are realized. The method provided by the invention realizes separation by utilizing the obvious difference of volatilization temperatures of ZrCl 4 and Cr, ni, mn and other impurity chlorides, can be directly embedded into the existing sponge zirconium chlorination production line, realizes directional removal of impurity elements, and has a zirconium recovery rate of not less than 90%.

Inventors

  • SUN YANDONG
  • CHEN QI
  • CHEN YING
  • ZHENG WEIFANG
  • YUAN ZHONGWEI
  • LIU FANG
  • YAN TAIHONG
  • JIA YANHONG
  • TANG HONGBIN
  • CAO ZHI
  • LI TIANCHI

Assignees

  • 中国原子能科学研究院

Dates

Publication Date
20260512
Application Date
20260105

Claims (10)

  1. 1. A chloridizing purification method for separating and recycling chromium, nickel and manganese impurities in zirconium materials comprises the following steps: s1, uniformly mixing an impurity-containing zirconium material and a carbon-containing reducing agent in proportion, placing the mixed material into a reaction device, and introducing chlorine at a set temperature for chlorination reaction to generate a crude ZrCl 4 gaseous mixture; S2, conveying the crude ZrCl 4 gaseous mixture generated by the reaction into a gas phase conveying pipeline of a pre-condenser for pre-cooling, so that the main impurity chloride is preferentially condensed and separated out; S3, introducing the pre-cooled gas-phase product into a main condenser for fractional condensation, so that efficient and stable removal of impurities and directional recovery of high-purity ZrCl 4 are realized.
  2. 2. The chloridizing purification method for separating and recycling chromium, nickel and manganese impurities in zirconium materials according to claim 1, wherein the molar ratio of the carbonaceous reducing agent to the zirconium materials containing impurities in the step S1 is 1.5-2.2.
  3. 3. The method for chloridizing and purifying chromium, nickel and manganese impurities in the recovered zirconium material according to claim 1, wherein the chloridizing reaction temperature in step S1 is 800-1000 ℃.
  4. 4. The method for chloridizing and purifying chromium, nickel and manganese impurities in the recovered zirconium material according to claim 3, wherein the chloridizing reaction temperature in the step S1 is 850-950 ℃.
  5. 5. The method for chloridizing and purifying chromium, nickel and manganese impurities in a recovered zirconium material according to claim 4, wherein the chloridizing reaction time in step S1 is 1-8 hours.
  6. 6. The method for chloridizing and purifying chromium, nickel and manganese impurities in a recovered zirconium material according to any one of claims 1 to 5, wherein in step S2, the pre-cooling is achieved by providing a gradient cooling zone or a physical filtration device in the gas phase transmission pipeline.
  7. 7. The method for chloridizing and purifying chromium, nickel and manganese impurities in a recovered zirconium material according to claim 1, wherein the pre-cooling temperature in step S2 is set to 500-600 ℃.
  8. 8. The method for chloridizing and purifying chromium, nickel and manganese impurities in the separated and recovered zirconium material according to claim 7, wherein in step S3, specifically: The main condenser comprises a second-stage medium-temperature transition condenser and a third-stage condenser, the pre-cooled gas-phase product firstly enters the second-stage medium-temperature transition condenser, the wall surface temperature of the second-stage medium-temperature transition condenser is controlled to be 400-500 ℃, at the temperature, residual trace impurities with boiling points higher than 400-500 ℃ are condensed and separated out and further removed, and the target product ZrCl 4 and low-boiling-point impurities keep to pass through in a gaseous state and enter the third-stage condenser; Controlling the wall temperature of the three-stage condenser to be 300-400 ℃, and at the temperature, a large amount of gaseous ZrCl 4 is sublimated and crystallized into solid to be efficiently collected.
  9. 9. The method for chloridizing and purifying chromium, nickel and manganese impurities in a recovered zirconium material according to claim 8, wherein in step S3, the wall temperature of the three-stage condenser is controlled to be 320-350 ℃.
  10. 10. The method for chloridizing and purifying chromium, nickel and manganese impurities in the separated and recovered zirconium material according to claim 8 or 9, wherein in the step S3, alkali liquor absorption or recovery treatment is performed on the uncondensed tail gas so as to meet the environmental protection requirement.

Description

Chlorination purification method for separating and recycling chromium, nickel and manganese impurities in zirconium material Technical Field The invention belongs to the technical field of nuclear fuel circulation and materials, and particularly relates to a chlorination purification method for separating and recycling chromium, nickel and manganese impurities in zirconium materials. Background Zirconium is a critical material for nuclear reactor fuel cladding, and its purity directly affects reactor operating safety and economy. In the production process of nuclear grade zirconium sponge, about 20% of unqualified products including surface oxides and filtering matters are produced in the peeling and filtering links of zirconium ingots. The materials are enriched with chromium, nickel, manganese and other metal impurities from production tools (such as a magnesia reduction crucible and a peeling pick). At present, the unqualified products are treated at low price of about 8.5 ten thousand yuan/ton, which is far lower than the market price of 48 ten thousand yuan/ton of qualified sponge zirconium, and huge economic losses of enterprises are caused. The annual direct loss reaches 245 ten thousand yuan based on the current 200 tons/annual energy yield, and if the productivity is increased to 2000 tons/year, the annual loss reaches 2450 ten thousand yuan. The existing reject recovery technology is mostly focused on returning the reject to the starting point of zircon sand chlorination purification or directly chloridizing after simple crushing. However, the former has long process flow, high energy consumption and poor economy, while the latter has irregular material shape and uneven physical properties, which is easy to cause uneven chlorination reaction and low efficiency, and more critical is that the enriched Cr, ni, mn and other impurities are difficult to be effectively separated under the conventional chlorination condition. This is due to the significant difference in the volatilization characteristics of ZrCl 4 and impurity chlorides, in that ZrCl 4 has a boiling point of about 331 ℃ and can be collected by sublimation in the 300-400 ℃ range, crCl 3 has a boiling point of about 1300 ℃ and NiCl 2、MnCl2 has a boiling point higher than 1000 ℃ and is difficult to volatilize at the ZrCl 4 condensation temperature, and should remain in the residue. However, if the chlorination process is improperly controlled, such as too high temperature, turbulence of air flow or inaccurate carbon proportioning, impurities can be wrapped or secondarily reacted, so that ZrCl 4 products are polluted, and the whole batch quality is affected. Even if part of the materials are recovered, the recovery rate and the product purity are difficult to ensure stably, so that the recovery process is not feasible in economy and technology. Therefore, a chlorination purification process capable of realizing efficient separation of impurities is urgently needed, the difficult problem of impurity removal in recovery of unqualified products is solved, and technical support is provided for recycling of nuclear-grade zirconium materials. Disclosure of Invention Aiming at the defects existing in the prior art, the invention aims to provide a chloridizing purification method for separating and recycling chromium, nickel and manganese impurities in zirconium materials, and the method can be used for realizing efficient and stable removal of the impurities in the zirconium materials and directional recycling of high-purity ZrCl 4. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: a chloridizing purification method for separating and recycling chromium, nickel and manganese impurities in zirconium materials comprises the following steps: s1, uniformly mixing an impurity-containing zirconium material and a carbon-containing reducing agent in proportion, placing the mixed material into a reaction device, and introducing chlorine at a set temperature for chlorination reaction to generate a crude ZrCl 4 gaseous mixture; S2, conveying the crude ZrCl 4 gaseous mixture generated by the reaction into a gas phase conveying pipeline of a pre-condenser for pre-cooling, so that the main impurity chloride is preferentially condensed and separated out; S3, introducing the pre-cooled gas-phase product into a main condenser for fractional condensation, so that efficient and stable removal of impurities and directional recovery of high-purity ZrCl 4 are realized. In the chloridizing purification method for separating and recycling chromium, nickel and manganese impurities in the zirconium material, the molar ratio of the carbon-containing reducing agent to the zirconium material containing the impurities in the step S1 is 1.5-2.2. Further, according to the chloridizing purification method for separating and recycling chromium, nickel and manganese impurities in the zirconium material, the chloridizing reaction temp