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CN-121974306-A - Preparation method and device of high-purity selenium

CN121974306ACN 121974306 ACN121974306 ACN 121974306ACN-121974306-A

Abstract

The invention belongs to the technical field of preparation of high-purity metal materials, and particularly relates to a preparation method and device of high-purity selenium. The preparation method of the high-purity selenium comprises the steps of immersing a first crystal bar and a flow baffle plate into a melt of raw material selenium under a protective atmosphere, performing primary rotary crystallization, taking out the first crystal bar to obtain a primary crystallization product, immersing a second crystal bar and the flow baffle plate into the melt of the primary crystallization product under the protective atmosphere, performing secondary rotary crystallization, and obtaining the high-purity selenium with the concentration of more than 6N on the second crystal bar, wherein the crystallization rate of the primary rotary crystallization is 0.1-0.5 mm/h, the crystallization rate of the secondary rotary crystallization is 0.5-1.5 mm/h, and the thickness of a solid-liquid boundary layer is less than or equal to 50 mu m. According to the invention, a flow baffle plate is added in the rotary crystallization process to strengthen convection of the melt, reduce the thickness of a boundary layer of a solid-liquid interface, accelerate impurity diffusion, control crystallization rate and improve crystallization efficiency, and the product purity is improved through twice crystallization, so that the obtained product is high-purity selenium with the purity of more than 6N.

Inventors

  • JIANG WENLONG
  • Bu Penglin
  • ZHA GUOZHENG
  • YANG BIN
  • LIU DACHUN
  • XU BAOQIANG
  • TIAN YANG
  • WANG FEI
  • LI YIFU

Assignees

  • 昆明理工大学

Dates

Publication Date
20260505
Application Date
20260309

Claims (10)

  1. 1. The preparation method of the high-purity selenium is characterized by comprising the following steps of: Under the protective atmosphere, immersing the first crystal bar and the flow baffle plate into a melt of raw material selenium for primary rotary crystallization, and taking out the first crystal bar to obtain a primary crystallization product; immersing a second crystal bar and a flow baffle plate into the melt of the primary crystallization product under a protective atmosphere, and then performing secondary rotary crystallization to obtain high-purity selenium on the second crystal bar, wherein the high-purity selenium is more than 6N high-purity selenium; The crystallization rate of the primary rotary crystallization is 0.1-0.5 mm/h, the crystallization rate of the secondary rotary crystallization is 0.5-1.5 mm/h, and the thickness of a solid-liquid boundary layer in the primary rotary crystallization and the secondary rotary crystallization is less than or equal to 50 mu m.
  2. 2. The method of claim 1, wherein the raw selenium melt has a temperature of 270-290 ℃.
  3. 3. The production method according to claim 1 or 2, wherein the rotational speed of the primary rotary crystallization is 10 to 60rpm.
  4. 4. The method according to claim 1, wherein the temperature of the melt of the primary crystallization product is 240 to 260 ℃.
  5. 5. The method according to claim 1 or 4, wherein the rotation speed of the secondary rotary crystallization is 60 to 120rpm.
  6. 6. The method according to claim 1, wherein the first crystallization rod is subjected to gradient cooling during the primary rotary crystallization, wherein the gradient cooling is that cooling is firstly carried out at a rate of 50 ℃ per hour to 230 ℃, then cooling is carried out at a rate of 5 ℃ per hour to 225 ℃, and finally cooling is carried out at a rate of 1 ℃ per hour to 219 ℃, and the temperature is kept for 2 hours; And the second crystallization rod is subjected to gradient cooling in the secondary rotary crystallization process, wherein the gradient cooling is that the temperature is firstly reduced to 210 ℃ at the speed of 50 ℃ per hour, then reduced to 205 ℃ at the speed of 5 ℃ per hour, finally reduced to 199 ℃ at the speed of 1 ℃ per hour, and the temperature is kept for 2 hours.
  7. 7. The preparation method according to claim 1, wherein the raw material selenium is 4N selenium, and the content of impurity elements in the 4N selenium is mercury and copper are independently less than or equal to 3ppm, boron, bismuth, lead, nickel, arsenic, antimony and tin are independently less than or equal to 5ppm, magnesium and aluminum are independently less than or equal to 8ppm, silicon is less than or equal to 9ppm, tellurium and iron are independently less than or equal to 40ppm, and sulfur is less than or equal to 40ppm.
  8. 8. The preparation method of the high-strength steel sheet according to claim 1, wherein the gas of the protective atmosphere is inert gas, the inert gas comprises argon, the protective atmosphere is micro negative pressure, and the micro negative pressure is 6000-90000 Pa.
  9. 9. The preparation device of the high-purity selenium is characterized by comprising an intelligent gas flow control module, a furnace shell, a heating body arranged in the furnace shell, a crucible arranged in the heating body, a liftable baffle plate and a crystallization rod; the intelligent gas flow control module comprises a gas inlet pipe and a gas outlet pipe, the gas inlet pipe and the gas outlet pipe are connected with the crystal bar, and an intelligent gas flowmeter is arranged on the gas inlet pipe.
  10. 10. The apparatus of claim 9, wherein the baffle is triangular prism-shaped.

Description

Preparation method and device of high-purity selenium Technical Field The invention belongs to the technical field of preparation of high-purity metal materials, and particularly relates to a preparation method and device of high-purity selenium. Background In the electronic industry, selenium is 4N-6N high-purity selenium. The 6N-grade high-purity selenium (the total impurity amount is less than 1 ppm) is a core material of a high-end photoelectric industry, the narrow band gap characteristic is that more than 6N selenium is needed to meet the conversion efficiency of CdTe solar cells, the infrared transmittance is that the Fe content of impurities is small, the performance of ZnSe military optical elements is guaranteed, and the X-ray detector is that the 6N selenium maintains the dark current stability. High purity selenium has become critical to the preparation of tip materials due to its excellent physicochemical properties. At present, the physical methods for preparing high-purity selenium comprise a vacuum distillation method and a zone melting method, the vacuum distillation method has more researches, but single vacuum distillation cannot remove substances with vapor pressure similar to that of selenium, impurity modification is needed, impurities with vapor pressure similar to that of selenium are oxidized, separation is realized, and only 4N selenium can be prepared by using the method. The zone melting method separates impurities on a solid-liquid interface by forming a movable melting zone in a quartz tube, so that the purity of selenium is improved, but the method has long period and high energy consumption. The crystallization method can theoretically realize the preparation of high-purity selenium according to the equilibrium distribution coefficient in the solid-liquid interface. In the traditional crystallization method, a crystallization rod is placed into a melt, a crystallization temperature is set, impurities or crystals are taken out after the crystallization is balanced, and then a clean crystallization rod is selected and placed into the crystals for recrystallization. The related art discloses a preparation method of 6N selenium, which is characterized in that a crystallizer is immersed into a melt of 4N selenium for rotary crystallization, but the preparation of 6N selenium can be realized only by multiple times of rotary crystallization (10-30 times), and the preparation period is long. Disclosure of Invention In view of the above, the present invention aims to provide a method and a device for preparing high purity selenium. According to the preparation method provided by the invention, the 6N high-purity selenium can be obtained only by rotating and crystallizing twice, and the preparation efficiency of the 6N high-purity selenium is improved. The invention provides a preparation method of high-purity selenium, which comprises the following steps: Under the protective atmosphere, immersing the first crystal bar and the flow baffle plate into a melt of raw material selenium for primary rotary crystallization, and taking out the first crystal bar to obtain a primary crystallization product; immersing a second crystal bar and a flow baffle plate into the melt of the primary crystallization product under a protective atmosphere, and then performing secondary rotary crystallization to obtain high-purity selenium on the second crystal bar, wherein the high-purity selenium is more than 6N high-purity selenium; The crystallization rate of the primary rotary crystallization is 0.1-0.5 mm/h, the crystallization rate of the secondary rotary crystallization is 0.5-1.5 mm/h, and the thickness of a solid-liquid boundary layer in the primary rotary crystallization and the secondary rotary crystallization is less than or equal to 50 mu m. Preferably, the temperature of the melt of the raw material selenium is 270-290 ℃. Preferably, the rotation speed of the primary rotary crystallization is 10-60 rpm. Preferably, the temperature of the melt of the primary crystallization product is 240-260 ℃. Preferably, the rotation speed of the secondary rotary crystallization is 60-120 rpm. Preferably, the first crystallization rod is subjected to gradient cooling in the primary rotary crystallization process, wherein the gradient cooling is that the temperature is firstly reduced to 230 ℃ at the speed of 50 ℃ per hour, then reduced to 225 ℃ at the speed of 5 ℃ per hour, finally reduced to 219 ℃ at the speed of 1 ℃ per hour, and the temperature is kept for 2 hours; And the second crystallization rod is subjected to gradient cooling in the secondary rotary crystallization process, wherein the gradient cooling is that the temperature is firstly reduced to 210 ℃ at the speed of 50 ℃ per hour, then reduced to 205 ℃ at the speed of 5 ℃ per hour, finally reduced to 199 ℃ at the speed of 1 ℃ per hour, and the temperature is kept for 2 hours. Preferably, the raw material selenium is 4N selenium, and the impurity e