阅读说明：本技术 一种高纯磷的制备工艺及装置 (Preparation process and device of high-purity phosphorus ) 是由 卢鹏荐 曾小龙 张�林 官建国 章嵩 于 2021-08-24 设计创作，主要内容包括：本发明公开了一种高纯磷的制备工艺及装置,所述工艺为,在惰性气体保护下,工业黄磷熔融态经酸洗、过滤后蒸馏,馏分在光照条件下经纳米TiO-(2)分离膜分离后冷却获得高纯度黄磷。本发明通过酸洗、吸附过滤、蒸馏及光催化钠滤多个提纯工序先后去除金属、非金属及有机物等杂质,可获得电子级的黄磷,极大地推动了电子级红磷的工业化。(The invention discloses a preparation process and a device of high-purity phosphorus, wherein the process comprises the steps of pickling and filtering industrial yellow phosphorus molten state under the protection of inert gas, distilling, and subjecting distillate to nano TiO under the condition of illumination 2 And cooling after separation by a separation membrane to obtain the high-purity yellow phosphorus. The invention removes impurities such as metal, nonmetal and organic matters through a plurality of purification processes of acid washing, adsorption filtration, distillation and photocatalytic sodium filtration, can obtain electronic-grade yellow phosphorus, and greatly promotes the industrialization of electronic-grade red phosphorus.)

1. The preparation process of high-purity phosphorus is characterized by comprising the following steps of: under the protection of inert gas, melting industrial yellow phosphorus, and passing through nano TiO under the condition of illumination₂And cooling after separation by a separation membrane to obtain the high-purity yellow phosphorus.

2. The process according to claim 1, wherein the light irradiation is UV with an intensity of 300 and 1200 lx.

3. The process according to claim 1, wherein the nano TiO is used as a binder₂The aperture of the separation membrane is 3-50 nm.

4. The preparation process according to claim 1, wherein the industrial yellow phosphorus is subjected to acid washing, filtration and distillation, and then is subjected to membrane separation; the distillation was carried out at 280 ℃ and 320 ℃ and the 260 ℃ and 280 ℃ fractions were collected.

5. The process according to claim 4, wherein the distillation is provided with packing comprising quartz rings and metallic fillers.

6. The preparation process of claim 1, wherein the acid washing process adopts 0.5-2mol/L nitric acid solution, and the addition amount of nitric acid is 10-30 wt% of yellow phosphorus.

7. The production device of the preparation process according to claim 1, which comprises a pickling tank (1), a filter (3), a quartz rectifying column (4), a photocatalytic reactor (7) and a cooling tank (8) which are communicated in sequence; the pickling tank (1) is provided with a heat-preservation jacket; the quartz rectifying column (3) is provided with a quartz ring and a metal filler, and the photocatalytic reactor (7) passes through nano TiO under an ultraviolet light source₂The membrane catalyzes the reaction.

8. The production plant according to claim 7, characterized in that a water washing tank (2) is also provided between the pickling tank (1) and the filter (3).

9. The production plant according to claim 7, characterized in that the photocatalytic reactor (7) is horizontal and comprises ultraviolet sources (701) arranged at both ends of the section, nano TiO concentrically distributed along the axial centerline₂A film (703), a feed inlet (702) located at the upper side and a discharge outlet (705) located at the lower side; the ultraviolet light source (701) is fixed on the left side and the right side of the photocatalytic reactor (7) through quartz flanges (704), and the nano TiO is₂The membrane (703) is arranged between two quartz flanges; when in work, the materials pass through the nano TiO from top to bottom₂The membrane (703) undergoes catalytic oxidation and is filtered.

10. The production device according to claim 9, wherein the photocatalytic reactor (7) is internally provided with a plurality of quartz tubes concentrically distributed along the axial center line, the surfaces of the quartz tubes are provided with pores, and the nano TiO is₂A thin film (703) is attached to the outer surface of the quartz tube.

Technical Field

The invention relates to the technical field of yellow phosphorus preparation processes, in particular to a preparation process and a preparation device of high-purity phosphorus.

Background

High-purity phosphorus chemical products have wide application, and InP, GaP and the like prepared from electronic-grade red phosphorus (6N) are important raw materials in the compound semiconductor industry and are dopants of planar epitaxial transistors and integrated circuits. The yellow phosphorus can be converted into red phosphorus by heating to 200-360 ℃ for several days under vacuum condition, and the yellow phosphorus is generally directly converted into the red phosphorus industrially.

As content in high-purity phosphorus needs to reach below 0.2ppm, even 0.05ppm, and currently, a plurality of methods for purifying industrial yellow phosphorus are reported: 1. chromatography: preparing a special chromatographic column by using a solid adsorbent or a carrier coated with metal, and separating gas yellow phosphorus and inert gas through the column to obtain semiconductor industrial-grade yellow phosphorus; 2. reduction of phosphine: the method is characterized in that phosphine is sent into a vacuum system to be cooled to remove impurities in gas, pure phosphine enters a pyrolysis furnace heated to 900 ℃ to be decomposed, the undecomposed phosphine is condensed in a gas condensation pipe cooled by liquid nitrogen, hydrogen is sent into an intermediate container along with the accumulation of the hydrogen, and elemental phosphorus is collected in a quartz bottle. The above two methods have very strict requirements on production conditions and have danger of explosion due to slight negligence.

Besides arsenic, industrial yellow phosphorus contains mechanical impurities, organic and inorganic impurities, such as: ca. Metal elements such as Fe, Al, Mg, Sr, Mn, Pb, Zn, Sn and the like; semimetal elements such As Se, Si, As, Bi, etc.; s and other non-metals; organic impurities such as phenol, anthracene, tar and polyatomic polycyclic aromatic hydrocarbon.

Since the industrial yellow phosphorus contains the impurities and seriously affects the application of converting the industrial yellow phosphorus into electronic-grade red phosphorus, the removal method of the yellow phosphorus impurities becomes a hot point of research. However, due to the complexity of yellow phosphorus impurities, the reported chemical method and physical method for removing arsenic from yellow phosphorus have problems of low phosphorus recovery rate, limited purification effect and the like.

Due to the complexity of the impurity components of the industrial yellow phosphorus, multiple purification methods are necessarily required to be designed for cooperation, and not only are new impurities prevented from being brought in the process of purifying the yellow phosphorus considered, but also the impurity removal process is considered to be associated in sequence to improve the removal efficiency.

Disclosure of Invention

The present invention is directed to a process for producing high-purity phosphorus, and a second object of the present invention is to provide an apparatus for producing high-purity phosphorus, which solves at least one of the problems of the prior art.

In view of the above, the technical scheme of the invention is as follows:

a preparation process of high-purity phosphorus comprises the following steps:

under the protection of inert gas, melting industrial yellow phosphorus, and passing through nano TiO under the condition of illumination₂And cooling after separation by a separation membrane to obtain the high-purity yellow phosphorus.

According to the embodiment of the invention, the illumination is UV, and the intensity is 300-.

According to the embodiment of the invention, the pore diameter of the nano TiO2 separation membrane is 3-50 nm.

According to the embodiment of the invention, the industrial yellow phosphorus is subjected to acid washing, filtration and distillation and then is subjected to membrane separation; the distillation was carried out at 280 ℃ and 320 ℃ and the 260 ℃ and 280 ℃ fractions were collected. Preferably, the distillation is provided with packing comprising quartz rings and metal fillers.

According to the embodiment of the invention, the acid washing process adopts 0.5-2mol/L nitric acid solution, and the addition amount of the nitric acid is 10-30 wt% of the yellow phosphorus.

The generating device of the preparation process comprises a pickling tank, a filter, a quartz rectifying column, a photocatalytic reactor and a cooling tank which are communicated in sequence; the pickling tank is provided with a heat-preservation jacket; the quartz rectifying column is provided with a quartz ring and a metal filler, and the photocatalytic reactor passes through nano TiO under an ultraviolet light source₂The membrane catalyzes the reaction.

According to the embodiment of the invention, a water washing tank is also arranged between the pickling tank and the filter.

According to the embodiment of the invention, the photocatalytic reactor is horizontal and comprises ultraviolet light sources arranged at two ends of the cross section and nano TiO which is concentrically distributed along the axial center line₂The film is positioned at the feed inlet on the upper side and the discharge outlet on the lower side; the ultraviolet light source is fixed on the left side and the right side of the photocatalytic reactor through quartz flanges, and the nano TiO is₂The film is arranged between the two quartz flanges; when in work, the materials pass through the nano TiO from top to bottom₂The film is subjected to catalytic oxidation reactionAnd filtered.

According to the embodiment of the invention, a plurality of quartz tubes concentrically distributed along the axial center line are arranged in the photocatalytic reactor, the surfaces of the quartz tubes are provided with pores, and the nano TiO is₂The film is attached to the outer surface of the quartz tube.

Compared with the prior art, the invention has the following effects:

1. the preparation process can effectively remove metal, heavy metal, mechanical impurities, inorganic and organic recombinant impurities and the like in the industrial yellow phosphorus, can obtain electronic-grade (6N) yellow phosphorus, and promotes the application of preparing high-purity yellow phosphorus from the industrial yellow phosphorus.

2. The invention adopts nano TiO₂The film can realize photocatalytic oxidation degradation of the organic heavy components under the anaerobic condition, and overcomes the difficulty that the organic heavy components are difficult to remove.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic view of the whole apparatus for preparing high-purity yellow phosphorus according to the present invention.

FIG. 2 is a schematic view of the structure of a photocatalytic reactor according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantageous effects of the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and the detailed description. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

The invention provides a preparation process and a device of high-purity phosphorus, which are used for effectively removing a plurality of impurities in industrial yellow phosphorus (99.9 wt%) to obtain electronic-grade yellow phosphorus, and are used for meeting the index requirement of converting the industrial yellow phosphorus into electronic-grade red phosphorus (6N) required by the semiconductor industry.

The preparation process of the high-purity phosphorus comprises the following steps:

s1, under the protection of inert gases (helium, nitrogen and the like), liquefying industrial yellow phosphorus in hot pure water at 50-80 ℃, stirring until the industrial yellow phosphorus is uniformly dispersed, adding 0.5-2mol/L nitric acid solution, stirring and pickling, wherein the amount of the nitric acid accounts for 10-30% of the mass of the yellow phosphorus;

s2, washing the pickling solution with hot pure water at the temperature of 45-80 ℃, and pumping the mixture of water and yellow phosphorus into a filter coated with diatomite for filtering under the condition of heat preservation;

s3, feeding the filtrate into a quartz rectifying column for distillation, wherein the quartz rectifying column is internally provided with a quartz ring and a metal filler, controlling the temperature at 320 ℃ and collecting fractions within the range of 280 ℃ and 260 ℃;

s4, subjecting the fraction to ultraviolet light with intensity of 300-₂Separating with a separation membrane, and cooling the separated material with pure water to separate out high-purity yellow phosphorus.

In the present invention, in step S2, the filter is preferably coated with a hydroxyl iron-coated diatomaceous earth on the surface of the filter element.

Preferably, the metal filler is one or more of metals such as iron, nickel, copper, manganese, chromium, cobalt and the like, and the quartz ring is high-purity quartz and can be of a pall ring, a ladder ring, a theta ring and the like.

Nano TiO in the invention₂The separation membrane adopts the preparation of mesoporous TiO2 membrane and the study of the adsorption property thereof in the Chinese published literature [ J]Wangshan et al functional material 2014 (stage 6): 70-74.

The preparation process is carried out under the condition that yellow phosphorus is in a liquid state, and the yellow phosphorus is easy to oxidize and therefore needs to be protected by inert gas. The choice of dilute nitric acid, pure water, may require a purity that matches that of high purity or electronic grade yellow phosphorus, as is common in the art.

The principle of the invention is as follows:

in step S1, the yellow phosphorus is in liquid state under the condition of hot pure water (50-80 ℃), the dilute nitric acid with low concentration has almost no oxidation at the temperature, and partial metals or heavy metals (such as Ca, Fe, Al, Mg, Sr, Mn, Na, K and the like) can be changed into ionic state and dissolved in water under the stirring action;

step S2, acid liquor can be effectively washed away after washing, and a filter coated with diatomite is adopted for filtering, so that mechanical impurities are filtered out, metal ions generated by acid washing are adsorbed, and in addition, As can be effectively adsorbed by the diatomite coated with the hydroxyl iron;

in step S3, a quartz glass rectifying column is used to effectively remove impurities such as inorganic salts and heavy components (e.g., tar). The mixed filler of the metal filler and the quartz ring is adopted, so that on one hand, nonmetal sulfur and the like can be adsorbed in the distillation process, and on the other hand, the effective overhigh distillation efficiency of the evaporation heat exchange area is increased; fractions in a lower temperature area are collected, heavy component impurities in the obtained yellow phosphorus fractions are further reduced in a backflow mode, and the purity is improved;

in the step S4, the obtained fraction is subjected to catalytic oxidation impurity removal and filtration by using a photocatalytic reactor, and nano TiO arranged in the reactor₂The film shows more active performance under certain ultraviolet illumination intensity. TiO2₂When irradiated with incident light having an energy greater than or equal to its energy gap (Eg), electrons in the valence band absorb photons and are excited, transitioning from the valence band to the conduction band, leaving holes in the valence band, thereby forming so-called electron-hole pairs, i.e., photogenerated carriers. Electrons generated by light excitation can directly reduce organic matters or react with an electron acceptor; the holes generated by light excitation can oxidize the organic matters, so that the organic matters undergo oxidation-reduction reaction and are degraded into CO₂And H₂O, even under the condition of no oxygen, in addition, because the nonmetal of arsenic (As) is weaker than yellow phosphorus and is easier to be oxidized, arsenic which is difficult to remove can be oxidized by controlling proper illumination intensity, arsenous acid is generated under the action of water, and the arsenic is easily removed after being dissolved in the water; in addition, the nano TiO₂The aperture of the film is 3-50nm, the nano structure of the film can permeate yellow phosphorus to block macromolecules, and trace impurities which are not completely removed can be effectively filtered.

The invention firstly adopts dilute nitric acid to carry outAcidification, because trace impurities are inevitably brought into dilute nitric acid, an acidification step is designed as the first step of the whole purification process, and the acidified metal is dissolved in water in an ionic state, so that the influence on the subsequent processes (such as reduction of the replacement influence on metal fillers of a quartz rectifying column and destructive influence on nano titanium dioxide) can be reduced; the acidification is followed by filtration, so that mechanical impurities can be effectively removed and metal ions can be adsorbed, and the removal of the mechanical impurities can effectively reduce the nano TiO₂And (4) blocking the mesoporous material of the film. The whole purification process removes heavy metals, mechanical impurities, non-metals, organic matters and macromolecular components in sequence, and the steps are synergistic, so that the feasibility and the reliability of the purification process are ensured.

As shown in fig. 1, the present invention provides a production apparatus for the above ultra-high purity phosphorus production process, comprising: 1. a pickling tank; 2. a water washing tank; 3. a filter; 4. a quartz rectifying column; 5. a quartz condenser; 6. a fraction collection tank; 7. a photocatalytic reactor; 8. a cooling tank; 11. a hot water feed pipe; 12. a dilute acid feeding pipe; 61. a return pipe; 71. a circulation pipe; 701. an ultraviolet light source; 702. a feed inlet; 703. nano TiO2₂A film; 704. a quartz flange; 705. and (4) a discharge port.

Wherein: the lower part of the pickling tank 1 is communicated with a water washing tank 2, the lower part of the water washing tank 2 is communicated with the input end of a filter 3, the output end of the filter 3 is communicated with the feeding side of a quartz rectifying column 4, the top of the quartz rectifying column 4 is communicated with a quartz condenser 5, the quartz condenser 5 is communicated with a fraction collecting tank 6, the bottom of the fraction collecting tank 6 is communicated with a photocatalytic reactor 7, and the bottom of the photocatalytic reactor 7 is communicated with the upper part of a cooling tank 8. The upper part of the pickling tank 1 is respectively provided with a hot water feeding pipe 11 and a dilute acid feeding pipe 12 which are respectively used for feeding hot water and dilute nitric acid, and the pickling tank 1 is also provided with a stirring paddle. The inside of the washing tank 2 is provided with a partition plate from bottom to top, the washing tank is divided into a left chamber and a right chamber, the upper parts of the left chamber and the right chamber are communicated with each other and can overflow, the feeding pipeline, the discharging pipeline and the pure water pipeline are respectively communicated with the right chamber, and the acidic water discharging pipeline is communicated with the left chamber. The filter 3 is a ceramic filter, and the surface of the filter element is coated with diatomite. The quartz rectifying column 4 is internally provided with quartz and metal fillers. The quartz condenser 4 is a common condenser structure and is provided with a tube side and a shell side for heat exchange. The tube pass is respectively communicated with the quartz rectifying column 4 and the fraction collecting tank 6, and the bottom of the fraction collecting tank 6 is provided with a return pipe 61 communicated with the upper part of the quartz condenser 4.

As shown in FIG. 2, the photocatalytic reactor 7 is horizontal, the ultraviolet lamp source 701 is disposed at two ends of the cross section, a plurality of quartz tubes concentrically distributed along the center line are disposed in the photocatalytic reactor 7, the surfaces of the quartz tubes are provided with pores, and the nano TiO is₂The film 703 is attached to the outer surface of the quartz tube, and the quartz tube is connected to the ultraviolet lamp source 701 through the quartz flange 704, so that ultraviolet light can penetrate through the quartz tube conveniently. The upper and lower sides of the photocatalytic reactor 7 are respectively provided with a feed inlet 702 and a discharge outlet 705. The feed inlet 702 is communicated with the fraction collecting tank 6, the discharge outlet 705 is communicated with the cooling tank 8, and the discharge outlet 705 is also communicated with the feed inlet 702 through a circulating pipe 71 to circulate the materials. The pipeline communicated with the discharge port 705 extends to the position below the liquid level in the cooling tank 8, so that air is isolated when the yellow phosphorus is cooled and separated out.

In the invention, in order to ensure the temperature for purifying the yellow phosphorus, the production device is also provided with necessary pipeline auxiliary heat, the elements are also provided with heat exchange interlayers, such as the pickling tank 1 and the fraction collecting tank 6 are provided with heat preservation jackets, and the cooling tank 8 is provided with a cooling interlayer. In addition, according to the process requirements, a conveying pump, a valve, an automatic control instrument and meter and the like for conveying materials are also arranged, and an exhaust valve for exhausting gas is also arranged.

In the present invention, in order to ensure the purity of yellow phosphorus, the material of each component is selected from relatively inert materials such as high-purity quartz.

When the production device works, before industrial yellow phosphorus is fed, all elements and pipelines of the whole device need to be washed, the impurity content in the washing water of the tail end cooling tank 8 is detected to be below 100ppb, then all emptying valves are closed, and inert gas is introduced into the device to exhaust air. As shown in figure 1, firstly adding hot pure water into a pickling tank 1, then adding industrial yellow phosphorus (stored in water), keeping the temperature at 50-80 ℃, pneumatically stirring after the yellow phosphorus is gradually liquefied, adding dilute nitric acid in proportion for acidification, and controlling the acidification time at 10-30 min; the acidizing fluid is discharged from the bottom and enters the right side of the baffle plate of the water washing tank 2, and hot pure water is added to the right side at the moment to perform acid washingAnd (3) washing the materials, overflowing the upper acid liquor to the left side and discharging, opening a material output valve at the bottom after the pH value of the discharged liquor to be detected is neutral, enabling the mixed material of yellow phosphorus and pure water to enter a filter 3 for filtering, closing the output valve if necessary, returning the filtrate to the filter for circulating filtration, and discharging until the S content in the detected yellow phosphorus is reduced to below 200 ppb. The filtrate enters a quartz rectifying column 4, the temperature is raised to 320 ℃ for 280 plus, yellow phosphorus is vaporized and then contacts a quartz ring and a metal filler for further adsorption, and then rises to the top of the tower, is condensed to below the boiling point by a quartz condenser 5, liquid yellow phosphorus enters a fraction collecting tank 6, when the temperature does not reach the 280 ℃ temperature range of 260 plus, a valve of a return pipe 61 is opened, the yellow phosphorus fully returns to enter the quartz rectifying column 4, and when the temperature reaches a control valve to control the return flow, the fraction collecting tank 6 collects the condensed fraction. When the temperature reaches the range of 260 ℃ and 280 ℃, the yellow phosphorus in the fraction collection tank 6 enters the photocatalytic reactor 7, and the yellow phosphorus enters the reactor along the feed inlet 702 and the nano TiO₂The film 703 is contacted, and strong light emitted by the ultraviolet light source 701 acts on the nano TiO through the quartz flange 704₂The surface of the film 703 is catalytically oxidized to degrade organic substances (such as long-chain aromatic hydrocarbons, heavy components such as tar) in the absence of oxygen, and yellow phosphorus penetrates through the multilayer nano TiO from top to bottom₂And finally discharging the liquid yellow phosphorus to a cooling tank 8 from a discharge port 705 at the bottom of the reactor, opening a circulating pipe 71 to return the materials to a feed port 701 when necessary, further improving the purity of the discharged materials by controlling the circulating amount, and separating the liquid yellow phosphorus from pure water after cooling to obtain the high-purity yellow phosphorus.

The following is an experimental example of the present invention, industrial yellow phosphorus was purchased from phosphorus group of Yunnan Jiang, Inc. in an amount of 99.9 wt%.

Example 1

Under the protection of nitrogen, 10.0kg of industrial yellow phosphorus is melted in hot pure water at 50-80 ℃, stirred until the industrial yellow phosphorus is uniformly dispersed, added with 1-3L of nitric acid solution with the concentration of 0.5-2mol/L, stirred and pickled, and the pickled liquid is washed by the hot pure water until the pH value is 7.

Example 2

The acidified water washing solution obtained in example 1 was filtered through a filter coated with celite under a constant temperature condition.

Example 3

The filtrate obtained in the example 2 is put into a quartz rectifying column for distillation, the temperature is raised to 280-320 ℃, and the fraction in the range of 260-280 ℃ is collected.

Example 4

The fraction obtained in example 3 was subjected to nano-TiO in UV light at an intensity of 300-₂Separating with a separating membrane to obtain nanometer TiO₂The aperture of the separation membrane is 3-50nm, and the separated material is cooled by pure water to separate out 9.67kg of yellow phosphorus.

Comparative example 1

The filtrate obtained in the example 2 is put into a quartz rectifying column for distillation, the temperature is raised to 280-320 ℃, and fractions at 220-260 ℃ are collected.

Comparative example 2

The filtrate obtained in the example 2 is put into a quartz rectifying column for distillation, the temperature is raised to 280-320 ℃, and the fraction above 280 ℃ is collected.

Comparative example 3

The filtrate obtained in example 2 was put into a quartz rectifying column for distillation, the temperature was raised to 325 ℃ or higher, and fractions at 260 ℃ and 280 ℃ were collected.

Comparative example 4

The fraction obtained in example 3 was subjected to nano-TiO in UV light at an intensity of 300-₂Separating with a separating membrane to obtain nanometer TiO₂The aperture of the separation membrane is 60nm, and the separated material is cooled by pure water to precipitate 9.69g of yellow phosphorus.

Comparative example 5

Example 3 the fraction obtained was subjected to nano-TiO in UV light at an intensity of 1300lx₂Separating with a separating membrane to obtain nanometer TiO₂The aperture of the separation membrane is 3-50nm, and the separated material is cooled by pure water to separate out 9.31g of yellow phosphorus.

Comparative example 6

The fraction obtained in comparative example 2 was treated in the same manner as in example 4 to obtain 8.35kg of yellow phosphorus.

Examples of the experiments

The industrial yellow phosphorus is detected before the purification treatment, and the method comprises the methods of Atomic Absorption Spectrometry (AAS), inductively coupled plasma-mass spectrometry and the like (ICP-MS). The main impurity content obtained by detection is as follows: 310ppm of mechanical impurities, 63ppm of As, 185ppm of S, 260ppm of Fe, 170ppm of Mn, 300ppm of organic components.

This experimental example examined the purity of yellow phosphorus and the content of target impurities in examples 1 to 4 and comparative examples 1 to 5, respectively, as shown in table 1.

Table 1: purity and impurity content of yellow phosphorus

As can be seen from the above data, example 1 significantly reduced the contents of Mn and Fe metals by acid washing and water washing; example 2 mechanical impurities were effectively reduced by filtration and adsorption of diatomaceous earth, and the content of As impurities was effectively reduced by the hydroxyl-coated diatomaceous earth. The organic components are reduced by rectification in example 3, since the high-boiling components are retained at the bottom of the column by rectification; in addition, the S content is remarkably reduced because the quartz ring and the metal packing filled in the rectification column can effectively adsorb the S content. Comparative example 1 a lower temperature fraction was selected than in example 2, containing a significant amount of low boiling organic impurities affecting purity. Comparative example 2 the selection of a higher temperature fraction than in example 2 had little effect on impurities but resulted in the loss of part of the yellow phosphorus (comparative example 6). The control group of comparative example 3 was selected to have a higher rectification temperature, since the temperature rise would cause a large amount of high boiling components to be distilled off, affecting purity. Comparative example 4 selection of larger pore size TiO₂The nano-film causes partial permeation of organic components because when the pore size is large, the surface tension of the liquid film on the pore size is smaller than the pressure, thereby permeating the surface pores. Comparative example 5 following higher intensity UV illumination, the intense light increased the TiO content₂The oxidation ability of the film causes part of the yellow phosphorus to be oxidized, resulting in a decrease in yield.

The invention is not limited solely to that described in the specification and embodiments, and additional advantages and modifications will readily occur to those skilled in the art, so that the invention is not limited to the specific details, representative apparatus, and illustrative examples shown and described herein, without departing from the spirit and scope of the general concept as defined by the appended claims and their equivalents.