Device for measuring arsenic content in industrial anhydrous hydrogen fluoride

Abstract

The utility model discloses a device for measuring arsenic content in industrial anhydrous hydrogen fluoride, and relates to the technical field of fluorine chemical analytical chemistry. The device comprises a bottom frame, an electric heating plate, a reaction assembly, a gas washing assembly and a bottle washing assembly, the electric heating plate, the reaction assembly, the gas washing assembly and the bottle washing assembly are located at the top of the bottom frame, and the reaction assembly is located between the gas washing assembly and the bottle washing assembly; the reaction assembly comprises a reaction cup, the top of the reaction cup is sleeved with a cup cover in a threaded mode, an air outlet pipe is installed on the cup cover, three fixing frames are fixedly connected into the cup cover, annular pipes are fixedly connected into the fixing frames, a plurality of nozzles are installed outside the annular pipes, and an air inlet pipe is fixedly connected into the cup cover. According to the device, trivalent arsenic is oxidized into pentavalent arsenic through the reaction assembly, then the electric heating plate is started for heating, HF and perchloric acid can be volatilized, azeotropic reaction of the trivalent arsenic element and hydrofluoric acid is avoided, acid gas can be absorbed through the gas washing assembly, and pollution and harm to workers are prevented.

Description

Technical Field

[0001] The utility model belongs to the technical field of analytical chemistry in fluorine chemical industry, and particularly relates to a measuring device for the arsenic content in industrial anhydrous hydrogen fluoride. Background Technique

[0002] Anhydrous hydrogen fluoride is produced from fluorite and sulfuric acid, and anhydrous hydrogen fluoride is generated by reaction. The AS in anhydrous hydrogen fluoride mainly comes from the raw material fluorite. Industrial anhydrous hydrogen fluoride is an important raw material for etching and cleaning agents, and is widely used in very large scale integrated circuit chips, solar cells, light emitting diodes, etc. The level of AS content directly affects the determination of the quality of industrial anhydrous hydrogen fluoride, and too high arsenic concentration will limit the application effect of hydrogen fluoride. Therefore, it is crucial to accurately measure and control the content in the process.

[0003] Since industrial anhydrous hydrogen fluoride and its diluted samples have strong corrosiveness, and the trivalent arsenic element contained in anhydrous hydrogen fluoride will undergo an azeotropic reaction with hydrofluoric acid, which will cause corrosion to the instrument;

[0004] For the existing analysis methods of arsenic content in industrial anhydrous hydrogen fluoride, the standard method GB 7746-2011 is usually implemented, and the silver diethyldithiocarbamate spectrophotometry is used for determination. This method has a long analysis process, high requirements for detection conditions, and poor reproducibility of the method; there are reports on the determination method of arsenic content in hydrofluoric acid using atomic fluorescence. Although this method can detect the arsenic content in hydrofluoric acid, due to the long sample pretreatment process, multiple dilutions and water baths are required, the result calculation is relatively cumbersome, and for the lower content of AS, due to multiple dilutions, the result cannot be accurately determined; and the water bath cannot completely remove HF, and there is still corrosion during instrument detection;

[0005] Another existing method for determining arsenic in industrial anhydrous hydrogen fluoride is to use ICP-oes for determination, but this instrument is expensive, and the detection cost is high for the determination of single-element AS.

[0006] Therefore, we provide a measuring device for the arsenic content in industrial anhydrous hydrogen fluoride to solve the above problems. Content of the Utility Model

[0007] The purpose of the utility model is to provide a measuring device for the arsenic content in industrial anhydrous hydrogen fluoride. By adding 2 ml of perchloric acid to the sample to oxidize trivalent arsenic to pentavalent arsenic, and then heating with an electric hot plate to volatilize HF and perchloric acid, the problem of the azeotropic reaction between trivalent arsenic element and hydrofluoric acid in the existing measurement process of arsenic content in industrial anhydrous hydrogen fluoride is solved.

[0008] To solve the above technical problems, the utility model is realized through the following technical solutions:

[0009] The utility model relates to a measuring device for arsenic content in industrial anhydrous hydrogen fluoride, which comprises a chassis, an electric heating plate, a reaction assembly, a gas washing assembly and a washing bottle assembly; the electric heating plate, the reaction assembly, the gas washing assembly and the washing bottle assembly are all located at the top of the chassis, and the reaction assembly is located between the gas washing assembly and the washing bottle assembly;

[0010] The reaction assembly includes a reaction cup which is placed on the top of the electric heating plate. A cup cover is threadedly sleeved on the top of the reaction cup. An air outlet pipe is installed on the cup cover. Three fixing frames are fixedly connected inside the cup cover. A ring pipe is fixedly connected inside the fixing frames. A plurality of nozzles are installed outside the ring pipe. An air inlet pipe is fixedly connected inside the cup cover and is communicated with the ring pipe. A dust-proof cover is installed on the top of the air inlet pipe.

[0011] The utility model is further provided that the gas washing assembly includes a gas washing bottle which is placed on the top of the chassis. A guide air pipe is fixedly connected inside the gas washing bottle. An air extraction pump is installed on the top of the chassis, and the air outlet pipe is installed at the input end of the air extraction pump. A connecting pipe is communicated between the air extraction pump and the guide air pipe.

[0012] The utility model is further provided that the washing bottle assembly includes a water holding bottle which is placed on the top of the chassis. A pressing pump is installed inside the water holding bottle. A water connecting pipe is arranged outside the air inlet pipe. A water inlet pipe is connected between the water connecting pipe and the output port of the pressing pump.

[0013] The utility model is further provided that the chassis includes a base plate. A vertical frame is fixedly connected to the top of the base plate, and the air extraction pump is fixedly connected to the top of the vertical frame. Four feet are fixedly connected to the bottom of the base plate, and anti-slip pads are fixedly connected to the bottoms of the four feet.

[0014] The utility model is further provided that a first limiting frame and a second limiting frame are fixedly connected to the top of the base plate, and the gas washing bottle and the water holding bottle are respectively located inside the first limiting frame and the second limiting frame.

[0015] The utility model is further provided that a threaded sleeve is fixedly connected to the bottom of the dust-proof cover, and the threaded sleeve is threadedly sleeved outside the air inlet pipe. A sealing gasket is fixedly connected to the top of the inner cavity of the dust-proof cover, and a first sealing ring is fixedly connected to the bottom of the inner cavity of the dust-proof cover.

[0016] The utility model is further provided that a feeding pipe is fixedly connected to the top of the cup cover and is communicated with the reaction cup. A sealing cover is threadedly sleeved on the top of the feeding pipe.

[0017] The utility model is further provided that the reaction cup is a tetrafluoro glass bottle, and a scale is arranged outside the reaction cup. The connecting pipe and the water inlet pipe are both flexible pipes.

[0018] The utility model is further provided that pure water is contained in the water holding bottle, and an alkaline solution is contained inside the gas washing bottle.

[0019] The utility model has the following beneficial effects:

[0020] 1. By adding 2 ml of perchloric acid into the sample, the trivalent arsenic can be oxidized to pentavalent arsenic in the utility model. Then, by starting the hot plate for heating, HF and perchloric acid can be volatilized, avoiding the azeotropic reaction between trivalent arsenic element and hydrofluoric acid.

[0021] 2. By pressing the pressing pump, pure water is pumped into the inside of the annular pipe through the water inlet pipe. Then, the pure water rushes towards the inner wall of the reaction cup through multiple nozzles, which can wash the inner wall of the reaction cup, reduce the drug residue on the inner wall, and reduce the detection error.

[0022] 3. By starting the air extraction pump, the acidic gas in the reaction cup is pumped into the alkaline solution in the washing bottle below the liquid level, so that the acidic gas can be absorbed, preventing HF and perchloric acid from polluting the atmosphere and avoiding harm to the health of the staff.

[0023] Of course, it is not necessary for any product implementing the utility model to achieve all the above advantages simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for describing the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 It is a schematic structural diagram of a measuring device for the arsenic content in industrial anhydrous hydrogen fluoride.

[0026] Figure 2 It is a schematic cross-sectional structure diagram of the washing bottle.

[0027] Figure 3 It is a schematic cross-sectional structure diagram of the reaction cup.

[0028] Figure 4 For Figure 3 the enlarged structural diagram at position A in

[0029] In the drawings, the list of components represented by each reference numeral is as follows:

[0030] 100 - chassis, 101 - substrate, 102 - pedestal, 103 - first limit frame, 104 - second limit frame, 105 - vertical frame, 200 - electric heating plate, 300 - reaction assembly, 301 - reaction cup, 302 - cup cover, 303 - exhaust pipe, 305 - fixing frame, 306 - annular pipe, 307 - nozzle, 308 - inlet pipe, 309 - dust cover, 309a - threaded sleeve, 309b - fixing ring, 309c - sealing gasket, 309d - first sealing ring, 310 - feeding pipe, 311 - sealing cover, 400 - gas washing assembly, 401 - gas washing bottle, 402 - guide pipe, 403 - exhaust pipe, 404 - air extraction pump, 405 - connecting pipe, 406 - bottle cap, 500 - washing bottle assembly, 501 - water holding bottle, 502 - pressing pump, 503 - water connecting pipe, 504 - water inlet pipe. Detailed implementation mode

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention. Embodiment 1

[0032] Please refer to Figure 1 and Figures 3 - 4 , the present invention is a measuring device for the arsenic content in industrial anhydrous hydrogen fluoride, including a chassis 100, an electric heating plate 200, a reaction assembly 300, a gas washing assembly 400 and a washing bottle assembly 500; the electric heating plate 200, the reaction assembly 300, the gas washing assembly 400 and the washing bottle assembly 500 are all located on the top of the chassis 100, and the reaction assembly 300 is located between the gas washing assembly 400 and the washing bottle assembly 500;

[0033] The reaction assembly 300 includes a reaction cup 301, the reaction cup 301 is placed on the top of the electric heating plate 200, a cup cover 302 is threadedly sleeved on the top of the reaction cup 301, an exhaust pipe 303 is installed on the cup cover 302, three fixing frames 305 are fixedly connected inside the cup cover 302, an annular pipe 306 is fixedly connected inside the fixing frame 305, a plurality of nozzles 307 are installed outside the annular pipe 306, an inlet pipe 308 is fixedly connected inside the cup cover 302, and the inlet pipe 308 is communicated with the annular pipe 306, a dust cover 309 is installed on the top of the inlet pipe 308. By heating the reaction cup 301 with the electric heating plate 200, HF and perchloric acid in the sample can be volatilized and removed, so that the co - boiling reaction between trivalent arsenic and hydrofluoric acid can be avoided;

[0034] The bottle washing assembly 500 includes a water storage bottle 501 placed on the top of the base frame 100. A pressing pump 502 is installed inside the water storage bottle 501. A water connection pipe 503 is arranged outside the air inlet pipe 308. A water inlet pipe 504 is connected between the water connection pipe 503 and the output port of the pressing pump 502. By adding pure water into the reaction cup 301, the inner wall of the reaction cup 301 can be cleaned to reduce the detection error. At the same time, it is also convenient to add water to dilute the sample after evaporation to dryness.

[0035] Specifically, the base frame 100 includes a base plate 101. A vertical frame 105 is fixedly connected to the top of the base plate 101, and the air extraction pump 404 is fixedly connected to the top of the vertical frame 105. Four feet 102 are fixedly connected to the bottom of the base plate 101, and anti-slip pads are fixedly connected to the bottoms of the four feet 102.

[0036] A first limiting frame 103 and a second limiting frame 104 are fixedly connected to the top of the base plate 101, and the gas washing bottle 401 and the water storage bottle 501 are respectively located inside the first limiting frame 103 and the second limiting frame 104. By providing the first limiting frame 103 and the second limiting frame 104, the gas washing bottle 401 and the water storage bottle 501 can be placed more stably.

[0037] Furthermore, a threaded sleeve 309a is fixedly connected to the bottom of the dust-proof cover 309, and the threaded sleeve 309a is threadedly sleeved outside the air inlet pipe 308. A sealing gasket 309c is fixedly connected to the top of the inner cavity of the dust-proof cover 309, and a first sealing ring 309d is fixedly connected to the bottom of the inner cavity of the dust-proof cover 309. By rotating the dust-proof cover 309, the dust-proof cover 309 moves downward along the air inlet pipe 308, and the air inlet pipe 308 can be blocked to prevent water from overflowing when adding water.

[0038] A feeding pipe 310 is fixedly connected to the top of the cup cover 302, and the feeding pipe 310 is communicated with the reaction cup 301. A sealing cover 311 is threadedly sleeved on the top of the feeding pipe 310. By providing the feeding pipe 310, it is convenient to add reagents into the reaction cup 301.

[0039] The water storage bottle 501 contains pure water, and the gas washing bottle 401 contains an alkaline solution.

[0040] The operation process of this embodiment is as follows: When it is necessary to process the sample, first add the sample into the reaction cup 301, and then add 2 ml of perchloric acid, so that trivalent arsenic can be oxidized to pentavalent arsenic. Then start the hot plate 200 and heat the reaction cup 301 at 105 °C for 30 minutes. Then raise the temperature of the hot plate 200 to 200 °C until thick smoke appears and stop heating, so that HF and perchloric acid can volatilize. Then press the pressing pump 502 to pump pure water into the inside of the annular pipe 306 through the water inlet pipe 504. Then the pure water rushes towards the inner wall of the reaction cup 301 through multiple nozzles 307, and the inner wall of the reaction cup 301 can be rinsed. Example 2

[0041] Please refer to Figures 1 - 2 , on the basis of the specific embodiment 1, the gas washing assembly 400 includes a gas washing bottle 401. The gas washing bottle 401 is placed on the top of the chassis 100. A gas guide pipe 402 is fixedly connected inside the gas washing bottle 401. A suction pump 404 is installed on the top of the chassis 100, and the air outlet pipe 303 is installed at the input end of the suction pump 404. A connecting pipe 405 is connected between the suction pump 404 and the gas guide pipe 402. Through the gas washing bottle 401, the acidic gas can be absorbed by the alkaline solution in the gas washing bottle 401, which can prevent HF and perchloric acid from volatilizing into the air and prevent pollution to the atmosphere and harm to the health of the staff.

[0042] Specifically, the reaction cup 301 is a tetrafluoro glass bottle, and a scale is arranged outside the reaction cup 301. Both the connecting pipe 405 and the water inlet pipe 504 are flexible hoses.

[0043] The operation process of this embodiment is as follows: By starting the suction pump 404, the air in the reaction cup 301 can be pumped out, and then it is introduced below the liquid level of the alkaline solution in the gas washing bottle 401 through the air outlet pipe 303, the connecting pipe 405 and the gas guide pipe 402 in sequence. The acidic gas can be absorbed by the alkaline solution. Then the treated air is discharged into the atmosphere through the air outlet pipe 403. At the same time, by rotating the dust-proof cover 309 upward to open the air inlet pipe 308, the outside air can be inhaled into the inside of the reaction cup 301 to keep the air pressure in the reaction cup 301 balanced. Example 3

[0044] Please refer to Figures 1 - 4 , on the basis of the specific embodiment 1 and the specific embodiment 2, specifically, a determination method for a measuring device of arsenic content in industrial anhydrous hydrogen fluoride specifically includes the following steps;

[0045] S1: Reagent preparation

[0046] Prepare thiourea-ascorbic acid solution (50 g / L):

[0047] First, weigh 50 g of thiourea and dissolve it in pure water. Then dilute it with water to 1000 ml. Subsequently, mix well and weigh 5 g of ascorbic acid, add it to a glass beaker containing 100 ml of thiourea solution (50 g / L) and dissolve and mix well. Prepare it freshly before use;

[0048] Prepare potassium borohydride solution (18 g / l):

[0049] First, weigh 5 g of sodium hydroxide and dissolve it in pure water. Then dilute it with water to 1000 ml and mix well. Then weigh 1.8 g of potassium borohydride and add it to a glass beaker containing 100 ml of sodium hydroxide solution (5 g / l), dissolve and mix well. Prepare it freshly before use;

[0050] Prepare arsenic standard solution (1 ppm): Pipette 1.00 ml of arsenic standard stock solution (0.100 mg / ml) into a 100 ml volumetric flask, add 5 ml of hydrochloric acid, dilute to the mark with water, and shake well (store in the refrigerator at 4 °C for three months);

[0051] S2: Weigh about 1 - 2 g of the sample (accurate to 0.0001 g) (when the arsenic content in the sample is too low, the sample amount can be increased), add it to the reaction cup 301, and then add 2 ml of perchloric acid;

[0052] S3: Start the air pump 404 to pump out the air in the reaction cup 301, and at the same time, outside air enters the reaction cup 301 through the air inlet pipe 308;

[0053] S4: Start the hot plate 200, heat the reaction cup 301 at 105 °C for 30 minutes, then raise the temperature of the hot plate 200 to 200 °C until thick smoke appears and stop heating. Let the reaction cup 301 cool slightly;

[0054] S5: Press the pressing pump 502 to pump pure water into the inside of the loop pipe 306 through the water inlet pipe 504, and then the pure water rushes towards the inner wall of the reaction cup 301 through multiple nozzles 307;

[0055] S6: Start the hot plate 200 again to heat the reaction cup 301 until the content in the reaction cup 301 is nearly dry, then turn off the hot plate 200 and cool the reaction cup 301;

[0056] S7: Open the sealing cover 311, then add 5 ml of hydrochloric acid (1 + 1) to the inside of the reaction cup 301 through the feeding pipe 310, and then start the hot plate 200 to slightly heat the reaction cup 301 to dissolve the salts;

[0057] S8: Transfer the above solution to a 50 ml volumetric flask, use the pressing pump 502 to rinse the reaction cup 301 several times and combine the washing solutions in the volumetric flask;

[0058] S9: Pipette 20 ml of the above solution into a 50-ml volumetric flask, then add 5 ml of (1+1) hydrochloric acid and 10 ml of thiourea-ascorbic acid solution, dilute to the mark with water, shake well, let stand for 30 min, and await measurement;

[0059] S10: Preparation of standard series

[0060] Pipette 0.125 ml, 0.25 ml, 0.50 ml, 0.75 ml, and 1.00 ml of arsenic standard solution (1 ppm) respectively into 50-ml volumetric flasks. Add 5 ml of hydrochloric acid (1+1) and 10 ml of thiourea-ascorbic acid solution, dilute to the mark with water, shake well, let stand for 30 min, and await measurement. The corresponding arsenic concentrations of these standard solutions are 2.5 ng / ml, 5.0 ng / ml, 10 ng / ml, 15 ng / ml, and 20 ng / ml;

[0061] S11: On an atomic fluorescence spectrometer, using hydrochloric acid (1+19) as the carrier, potassium borohydride solution as the reducing agent, and an arsenic hollow cathode lamp as the excitation source, sequentially measure the fluorescence intensities of the standard blank solution, standard solution, sample blank solution, and sample solution. With the arsenic standard solution concentration as the abscissa and the fluorescence intensity after deducting the standard solution blank as the ordinate, plot a calibration curve. Subtract the fluorescence intensity of the sample blank solution from the fluorescence intensity of the sample solution, and find the corresponding arsenic concentration from the calibration curve.

[0062] In the description of this specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0063] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not elaborate on all the details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the present invention, so that those skilled in the relevant art can understand and utilize the present invention well. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A measuring device for the arsenic content in industrial anhydrous hydrogen fluoride, comprising a chassis (100), a hot plate (200), a reaction assembly (300), a gas washing assembly (400) and a washing bottle assembly (500); characterized in that: The electric hot plate (200), reaction assembly (300), gas washing assembly (400) and washing bottle assembly (500) are all located at the top of the chassis (100), and the reaction assembly (300) is located between the gas washing assembly (400) and the washing bottle assembly (500). The reaction assembly (300) includes a reaction cup (301), the reaction cup (301) is placed on the top of the electric hot plate (200), a cup cover (302) is threadedly sleeved on the top of the reaction cup (301), an air outlet pipe (303) is installed on the cup cover (302), three fixing frames (305) are fixedly connected inside the cup cover (302), a ring pipe (306) is fixedly connected inside the fixing frame (305), a plurality of nozzles (307) are installed on the outside of the ring pipe (306), an air inlet pipe (308) is fixedly connected inside the cup cover (302), and the air inlet pipe (308) is communicated with the ring pipe (306), and a dust-proof cover (309) is installed on the top of the air inlet pipe (308).

2. The measuring device for arsenic content in industrial anhydrous hydrogen fluoride according to claim 1, characterized in that, The gas washing assembly (400) includes a gas washing bottle (401), the gas washing bottle (401) is placed on the top of the chassis (100), a guide air pipe (402) is fixedly connected inside the gas washing bottle (401), an air extraction pump (404) is installed on the top of the chassis (100), and the air outlet pipe (303) is installed at the input end of the air extraction pump (404), and a connecting pipe (405) is communicated between the air extraction pump (404) and the guide air pipe (402).

3. The measuring device for the arsenic content in industrial anhydrous hydrogen fluoride according to claim 2, characterized in that, The washing bottle assembly (500) includes a water storage bottle (501), the water storage bottle (501) is placed on the top of the chassis (100), a pressing pump (502) is installed inside the water storage bottle (501), a water connection pipe (503) is arranged outside the air inlet pipe (308), and a water inlet pipe (504) is connected between the water connection pipe (503) and the output port of the pressing pump (502).

4. The measuring device for the arsenic content in industrial anhydrous hydrogen fluoride according to claim 2, characterized in that, The chassis (100) includes a base plate (101), a vertical frame (105) is fixedly connected to the top of the base plate (101), and the air extraction pump (404) is fixedly connected to the top of the vertical frame (105), and four feet (102) are fixedly connected to the bottom of the base plate (101), and anti-slip pads are fixedly connected to the bottoms of the four feet (102).

5. The measuring device for the arsenic content in industrial anhydrous hydrogen fluoride according to claim 4, characterized in that, A first limit frame (103) and a second limit frame (104) are fixedly connected to the top of the base plate (101), and the gas washing bottle (401) and the water storage bottle (501) are respectively located inside the first limit frame (103) and the second limit frame (104).

6. The measuring device for the arsenic content in industrial anhydrous hydrogen fluoride according to claim 1, characterized in that A threaded sleeve (309a) is fixedly connected to the bottom of the dust-proof cover (309), and the threaded sleeve (309a) is threadedly sleeved on the outside of the air inlet pipe (308), a sealing gasket (309c) is fixedly connected to the top of the inner cavity of the dust-proof cover (309), and a first sealing ring (309d) is fixedly connected to the bottom of the inner cavity of the dust-proof cover (309).

7. The measuring device for the arsenic content in industrial anhydrous hydrogen fluoride according to claim 1, characterized in that, The top of the cup cover (302) is fixedly connected with a feeding pipe (310), and the feeding pipe (310) is communicated with the reaction cup (301). A sealing cover (311) is threadedly sleeved on the top of the feeding pipe (310).

8. The measuring device for the arsenic content in industrial anhydrous hydrogen fluoride according to claim 2, wherein The reaction cup (301) is a tetrafluoroethylene glass bottle, and scales are arranged on the outside of the reaction cup (301). Both the connecting pipe (405) and the water inlet pipe (504) are flexible hoses.

9. The measuring device for arsenic content in industrial anhydrous hydrogen fluoride according to claim 3, characterized in that, The water storage bottle (501) contains pure water, and the inside of the gas washing bottle (401) contains an alkaline solution.

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