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CN-122012950-A - Method and equipment for purifying metallic antimony

CN122012950ACN 122012950 ACN122012950 ACN 122012950ACN-122012950-A

Abstract

The invention provides a method for purifying metallic antimony, and relates to the technical field of antimony purification. The method for purifying the metallic antimony comprises the following steps of placing raw material crude antimony in an evaporation area in a closed vacuum furnace body, vacuumizing the furnace body, melting and evaporating the crude antimony in the evaporation area by heating, and moving the mixed vapor upwards. The condensing tower is divided into three temperature areas from bottom to top along the vertical direction, namely a lower high-temperature reflux section, a middle intermediate-temperature transition section and an upper low-temperature trapping section. The high-purity antimony vapor is crystallized and separated out on a selective condensing plate of a lower high-temperature reflux section. Part of the antimony vapor containing the intermediate impurities is condensed in the intermediate temperature transition section and is refluxed to the evaporation zone to participate in the evaporation to condensation process again. Volatile impurity vapors are captured at an upper low temperature capture Duan Lengning. The invention can improve the separation efficiency, and can effectively remove impurities such as arsenic and the like at the same time so as to improve the purification effect. In addition, the invention also provides equipment for realizing the purification method of the metallic antimony.

Inventors

  • Zhou Tanyuan
  • LIU WENWEN

Assignees

  • 成都迈和半导体材料有限公司

Dates

Publication Date
20260512
Application Date
20260324

Claims (10)

  1. 1. A method for purifying metallic antimony, which is characterized by comprising the following steps: s101, placing raw material crude antimony in an evaporation area in a closed vacuum furnace body; S102, vacuumizing the furnace body to enable the pressure in the furnace to reach 0.1 Pa-1.0 Pa; S103, heating the evaporation area to 700-800 ℃ to melt and evaporate the crude antimony, so as to generate mixed vapor of antimony and impurity elements; s104, enabling the mixed vapor to move upwards, and sequentially passing through a multistage stepped condensing tower arranged in the vertical direction, wherein the condensing tower is divided into three temperature areas from bottom to top along the vertical direction: the temperature of the lower high-temperature reflux section is controlled to be 580-620 ℃; the middle temperature transition section is controlled at 450-550 ℃; The upper low-temperature trapping section is controlled at 120-400 ℃; s105, crystallizing and separating out high-purity antimony vapor on a selective condensing plate of the lower high-temperature reflux section to form a main product; S106, part of the antimony vapor containing the intermediate impurities is condensed in the intermediate temperature transition section of the middle part and flows back to the evaporation zone to participate in the evaporation to condensation process again; s107, capturing volatile impurity vapor at the upper low-temperature capturing Duan Lengning; s108, after distillation is finished, obtaining a high-purity antimony main product from a lower high-temperature reflux section, obtaining an intermediate product containing intermediate impurities from a middle intermediate-temperature transition section, and obtaining an impurity concentrate from an upper low-temperature trapping section.
  2. 2. The method for purifying metallic antimony according to claim 1, wherein the raw material crude antimony in the step S101 is industrial crude antimony with a purity of 99.99% or more, and is crushed to a particle size of 20-40 mm before use.
  3. 3. The method for purifying metallic antimony according to claim 1, wherein the heating rate of the heating evaporation zone in step S103 is 5 to 10 ℃ per minute, and the temperature is maintained at 300 ℃ and 500 ℃ for 20 to 40 minutes, respectively.
  4. 4. The method for purifying metallic antimony according to claim 1, wherein the temperature control accuracy of the three temperature zones in step S104 is ±10 ℃.
  5. 5. The method according to claim 1, wherein the reflux to the evaporation zone in step S106 is specifically that an inverse conical reflux structure is disposed on an inner wall of the condensing tower at the middle intermediate temperature transition section, and is used for condensing part of the antimony vapor containing the intermediate impurities and adhering the part of the antimony vapor to a surface of the inverse conical reflux structure, and a cone angle of the inverse conical reflux structure is 30 ° to 60 °.
  6. 6. The method for purifying metallic antimony according to claim 1, wherein the distillation time is 12 to 18 hours.
  7. 7. The method for purifying metallic antimony according to claim 1, wherein the purity of the high-purity antimony main product is not less than 99.999%, wherein the arsenic content is not more than 1ppm, the lead content is not more than 0.5ppm, and the bismuth content is not more than 0.5ppm.
  8. 8. An apparatus for carrying out the purification method of metallic antimony according to any one of claims 1 to 7, comprising: a vertical vacuum furnace body; the vacuum system is connected with the furnace body and is used for enabling the furnace to reach and maintain the required vacuum degree; The evaporation area is arranged at the bottom of the furnace body, and a crucible and a heating device for containing raw materials are arranged in the evaporation area; the multistage fractional condensation tower of setting in evaporation zone top, the condensation tower has set gradually from bottom to top along the vertical direction: the lower high-temperature reflux section is internally provided with a first temperature control unit and a first condensing plate; The middle temperature transition section is internally provided with a second temperature control unit and an inverted cone-shaped reflux structure; the upper low-temperature trapping section is internally provided with a third temperature control unit and a second condensing plate; The product collecting unit, the intermediate product collecting unit and the impurity collecting unit are respectively connected with the lower high-temperature reflux section, the middle intermediate-temperature transition section and the upper low-temperature capturing section; And the PID controller is respectively connected with the first temperature control unit, the second temperature control unit and the third temperature control unit.
  9. 9. The apparatus of claim 8, wherein the inverted cone-shaped reflux structure is a plurality of inverted cone-shaped baffles provided on an inner wall of the condensing tower, and an air flow channel and a reflux channel are formed between adjacent baffles.
  10. 10. The apparatus of claim 8, wherein the vacuum system comprises a vacuum pump in communication with the furnace body.

Description

Method and equipment for purifying metallic antimony Technical Field The invention relates to the technical field of antimony purification, in particular to a method and equipment for purifying metallic antimony. Background The metallic antimony is used as an important strategic rare metal and is widely applied to the fields of semiconductors, infrared detectors, battery alloys, flame retardants and the like. With the rapid development of high and new technology industries such as aerospace, remote sensing and remote control, infrared detection and the like, the demand for high-purity antimony (the purity is more than or equal to 99.999 percent, namely 5N grade) and even ultra-purity antimony (the purity is more than or equal to 99.9999 percent, namely 6N grade) is increasingly urgent. Very small amounts of impurity elements in high purity antimony, particularly arsenic (As), lead (Pb), bismuth (Bi), iron (Fe), etc., can significantly affect the photoelectric properties thereof and the quality of the compound semiconductor material. At present, the preparation method of the high-purity antimony mainly comprises the processes of electrolytic refining, zone smelting, vacuum distillation and combination thereof. The method for preparing the antimony compound from the antimony ore or the antimony white disclosed in the prior art has the problems that the purity of the product is limited and the requirement of more than 5N is difficult to reach. Some existing methods can effectively improve the purity of the product to reach more than 5N, but have the problems of long process flow, multiple equipment and low efficiency. For the purification of antimony, vacuum distillation purification can be adopted, and the principle of vacuum distillation purification of metals is that different elements have different saturated vapor pressures under vacuum conditions. The existing vacuum distillation technology generally adopts a single-stage evaporation-condensation mode, namely, antimony is evaporated at a certain temperature, and then condensed and collected on a condensation plate. However, because arsenic and antimony are the same group elements and have similar physical and chemical properties, single-stage distillation is difficult to deeply remove the arsenic to below 1ppm, and meanwhile, for intermediate impurities (such as sulfur, selenium and the like) with saturated vapor pressure between that of the antimony and the arsenic, single-stage distillation is often volatilized and condensed along with the antimony, so that the purity of a product is influenced. Therefore, a high-purity antimony purification method which has high separation efficiency and can simultaneously and effectively remove impurities such as arsenic is required in the market. Disclosure of Invention The invention aims to provide a method for purifying metallic antimony, which can improve the separation efficiency and simultaneously and effectively remove impurities such as arsenic and the like so as to improve the purification effect. It is another object of the present invention to provide an apparatus for carrying out the above purification method of metallic antimony. Embodiments of the present invention are implemented as follows: The embodiment of the application provides a method for purifying metallic antimony, which comprises the following steps: s101, placing raw material crude antimony in an evaporation area in a closed vacuum furnace body; S102, vacuumizing the furnace body to enable the pressure in the furnace to reach 0.1 Pa-1.0 Pa; S103, heating the evaporation area to 700-800 ℃ to melt and evaporate the crude antimony, so as to generate mixed vapor of antimony and impurity elements; s104, enabling the mixed vapor to move upwards, and sequentially passing through a multistage stepped condensing tower arranged in the vertical direction, wherein the condensing tower is divided into three temperature areas from bottom to top along the vertical direction: the temperature of the lower high-temperature reflux section is controlled to be 580-620 ℃; the middle temperature transition section is controlled at 450-550 ℃; The upper low-temperature trapping section is controlled at 120-400 ℃; s105, crystallizing and separating out high-purity antimony vapor on a selective condensing plate of the lower high-temperature reflux section to form a main product; S106, part of the antimony vapor containing the intermediate impurities is condensed in the intermediate temperature transition section of the middle part and flows back to the evaporation zone to participate in the evaporation to condensation process again; s107, capturing volatile impurity vapor at the upper low-temperature capturing Duan Lengning; s108, after distillation is finished, obtaining a high-purity antimony main product from a lower high-temperature reflux section, obtaining an intermediate product containing intermediate impurities from a middle intermediate-temperature transiti