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CN-122016993-A - Method for detecting boron and phosphorus impurities in polycrystalline silicon recovered hydrogen for photovoltaic

CN122016993ACN 122016993 ACN122016993 ACN 122016993ACN-122016993-A

Abstract

The invention discloses a method for detecting boron and phosphorus impurities in polycrystalline silicon recovered hydrogen for photovoltaic, which belongs to the technical field of polycrystalline silicon recovered hydrogen detection and comprises the steps of taking two absorption bottles as sample absorption bottles, taking the remaining two absorption bottles as blank absorption bottles, finally adding silver nitrate solution into each absorption bottle, installing the two sample absorption bottles on a sampler after being connected in series, then introducing recovered hydrogen, enabling the recovered hydrogen to pass through the silver nitrate solution, enabling the silver nitrate solution to absorb the boron and phosphorus impurities in the recovered hydrogen, enabling the two sample absorption bottles not to be connected with the sampler, weighing the two sample absorption bottles together with an internal solution, detecting by adopting an inductive coupling plasma mass spectrometer, obtaining the boron and phosphorus impurity element content in sample absorption liquid, obtaining the boron and phosphorus impurity element content in the blank solution in the same detection mode, and calculating to obtain the boron and phosphorus impurity element content in the recovered hydrogen. The invention can accurately detect the content of boron and phosphorus elements in the recovered hydrogen.

Inventors

  • WANG CHUNMING
  • ZHANG JUAN
  • ZHANG YUQUAN
  • MENG KUN

Assignees

  • 江苏中能硅业科技发展有限公司

Dates

Publication Date
20260512
Application Date
20260403

Claims (8)

  1. 1. A detection method for boron and phosphorus impurities in recovered hydrogen of polycrystalline silicon for photovoltaic is characterized by comprising the following steps: Step a, cleaning four double-hole absorption bottles with covers by using ultrapure water, drying by using nitrogen, wherein two absorption bottles are used as sample absorption bottles, the remaining two absorption bottles are used as blank absorption bottles, and finally adding silver nitrate solution into each absorption bottle; B, installing two sample absorption bottles on a sampler after being connected in series, then introducing recovered hydrogen, and enabling the recovered hydrogen to pass through a silver nitrate solution to enable the silver nitrate solution to absorb boron and phosphorus impurities in the recovered hydrogen, wherein the two sample absorption bottles are subjected to sealing treatment and are not connected with the sampler; C, after the absorption is finished, weighing the two sample absorption bottles together with the internal solution, mixing the solutions in the two sample absorption bottles together, and detecting by adopting an inductively coupled plasma mass spectrometer to obtain the contents of boron and phosphorus impurity elements in the sample absorption liquid; Step d, mixing the solutions in the two blank absorption bottles together, and detecting by adopting an inductively coupled plasma mass spectrometer to obtain the contents of boron and phosphorus impurity elements in the blank solution; And e, calculating according to the weight of the sample absorption bottle, the weight of the sample absorption bottle and the internal solution, the contents of the boron and phosphorus impurity elements in the sample absorption liquid and the contents of the boron and phosphorus impurity elements in the blank solution to obtain the contents of the boron and phosphorus impurity elements in the recovered hydrogen.
  2. 2. The method for detecting boron and phosphorus impurities in the recovered hydrogen gas of the polycrystalline silicon for the photovoltaic use according to claim 1, wherein in the step a, the concentration of the silver nitrate solution is 0.04-0.06 g/L.
  3. 3. The method for detecting boron and phosphorus impurities in the recovered hydrogen gas of the polysilicon for the photovoltaic device according to claim 1, wherein in the step a, the absorbing bottle is made of PFA.
  4. 4. The method for detecting boron and phosphorus impurities in the recovered hydrogen of the polysilicon for the photovoltaic use according to claim 1, wherein in the step a, the volumes of silver nitrate solutions in the absorption bottles are the same and are 40-60 mL.
  5. 5. The method for detecting boron and phosphorus impurities in the polycrystalline silicon recovered hydrogen for the photovoltaic use according to claim 1, wherein in the step b, the gas inlet flow rate of the recovered hydrogen into the sample absorption bottle is 0.4-0.6L/min, and the gas inlet time is 100-140 min.
  6. 6. The method for detecting boron and phosphorus impurities in the recovered hydrogen of the polysilicon for the photovoltaic device according to claim 1, wherein the content of boron and phosphorus impurity elements in the sample absorption liquid in the step c and the content of boron and phosphorus impurity elements in the hollow white solution in the step d are repeatedly measured at least twice until the relative deviation between the two parallel measurement is not more than 15%, and the average value is obtained.
  7. 7. The method for detecting boron and phosphorus impurities in the recovered hydrogen gas of the polysilicon for the photovoltaic device according to claim 1, wherein in the step e, the calculation formula of the content of the boron and phosphorus impurity elements in the recovered hydrogen gas is as follows: ; wherein M represents the content of boron or phosphorus impurity elements in the recovered hydrogen, Represents the content of boron or phosphorus impurity elements in the absorption liquid, Represents the content of boron or phosphorus impurity elements in the blank solution of the blank sample bottle, Indicating the weight of the sample absorbing bottle along with the internal solution, The weight of the sample absorbing bottle is indicated, Represents the recycled hydrogen gas inlet volume under the standard state, Representing the density of hydrogen.
  8. 8. The method for detecting boron and phosphorus impurities in the recovered hydrogen gas of the polysilicon for the photovoltaic device according to claim 7, wherein the recovered hydrogen gas in a standard state is introduced into the volume The calculation formula of (2) is as follows: ; Wherein, the The atmospheric pressure value at the time of absorption is indicated, The temperature of the sample is indicated as a standard temperature, Represents the flow rate of the intake air, The time of intake air is indicated as being, The standard pressure is indicated as such, The temperature value at the time of absorption is shown.

Description

Method for detecting boron and phosphorus impurities in polycrystalline silicon recovered hydrogen for photovoltaic Technical Field The invention relates to a method for detecting boron and phosphorus impurities in polycrystalline silicon recovered hydrogen for photovoltaic, and belongs to the technical field of polycrystalline silicon recovered hydrogen detection. Background The polysilicon reduction tail gas for the photovoltaic is mainly hydrogen, contains a small amount of chlorosilane, nitrogen, hydrogen chloride, metal, nonmetal elements and other impurities, and can be reused for reduction after impurity removal and drying so as to reduce the production cost. The quality of the recovered hydrogen is an important factor influencing the quality of the polysilicon, wherein the boron, phosphorus and other element impurities mainly exist in the form of chlorides, diborane and phosphine, and the accurate detection of the content of the boron, phosphorus and other element impurities has a vital guiding significance for the recovery and utilization of the recovered hydrogen. The prior art lacks a method capable of accurately detecting the contents of boron and phosphorus elements in the recovered hydrogen. Disclosure of Invention The invention aims to overcome the defects of the prior art, and provides a method for detecting boron and phosphorus impurities in the recovered hydrogen of the polycrystalline silicon for photovoltaic, which can accurately detect the content of boron and phosphorus elements in the recovered hydrogen. In order to solve the technical problems, the invention adopts the following technical scheme: a detection method for boron and phosphorus impurities in polycrystalline silicon recovered hydrogen for photovoltaic comprises the following steps: Step a, cleaning four double-hole absorption bottles with covers by using ultrapure water, drying by using nitrogen, wherein two absorption bottles are used as sample absorption bottles, the remaining two absorption bottles are used as blank absorption bottles, and finally adding silver nitrate solution into each absorption bottle; B, installing two sample absorption bottles on a sampler after being connected in series, then introducing recovered hydrogen, and enabling the recovered hydrogen to pass through a silver nitrate solution to enable the silver nitrate solution to absorb boron and phosphorus impurities in the recovered hydrogen, wherein the two sample absorption bottles are subjected to sealing treatment and are not connected with the sampler; C, after the absorption is finished, weighing the two sample absorption bottles together with the internal solution, mixing the solutions in the two sample absorption bottles together, and detecting by adopting an inductively coupled plasma mass spectrometer to obtain the contents of boron and phosphorus impurity elements in the sample absorption liquid; Step d, mixing the solutions in the two blank absorption bottles together, and detecting by adopting an inductively coupled plasma mass spectrometer to obtain the contents of boron and phosphorus impurity elements in the blank solution; And e, calculating according to the weight of the sample absorption bottle, the weight of the sample absorption bottle and the internal solution, the contents of the boron and phosphorus impurity elements in the sample absorption liquid and the contents of the boron and phosphorus impurity elements in the blank solution to obtain the contents of the boron and phosphorus impurity elements in the recovered hydrogen. In the step a, the concentration of the silver nitrate solution is 0.04-0.06 g/L. In the step a, the material of the absorption bottle is PFA. In the step a, the volume of the silver nitrate solution in each absorption bottle is 40-60 mL. In the step b, the air inlet flow rate of the recovered hydrogen gas to the sample absorption bottle is 0.4-0.6L/min, and the air inlet time is 100-140 min. And c, repeatedly measuring the contents of the boron and phosphorus impurity elements in the sample absorption liquid in the step d and the contents of the boron and phosphorus impurity elements in the hollow white solution at least twice until the relative deviation between the two parallel measurement is not more than 15%, and taking an average value. In the step e, the calculation formula of the content of boron and phosphorus impurity elements in the recovered hydrogen is as follows: ; wherein M represents the content of boron or phosphorus impurity elements in the recovered hydrogen, Represents the content of boron or phosphorus impurity elements in the absorption liquid,Represents the content of boron or phosphorus impurity elements in the blank solution of the blank sample bottle,Indicating the weight of the sample absorbing bottle along with the internal solution,The weight of the sample absorbing bottle is indicated,Represents the recycled hydrogen gas inlet volume under the standard state,Representing the