Method for detecting wet content of chlorosilane and chlorosilane polymer in filter residue of hydrogenation system

Abstract

The application discloses a detection method for the wet content of chlorosilane and chlorosilane polymer in hydrogenation system filter residue, and belongs to the technical field of detection of hydrogenation system filter residue. The method comprises the following steps: after a sample bottle is cleaned, nitrogen is used to blow off moisture, and the mass of the sample bottle is weighed; a filter residue sample is weighed and placed in the sample bottle; one hole of the sample bottle is connected with a nitrogen inlet pipe, and the other hole is connected with one end of an exhaust pipe; the other end of the exhaust pipe is inserted into an alkaline recovery solution, and the sample bottle is placed on a heating plate for continuous heating and drying; after the heating plate continuously heats and dries for a period of time, the mass of the sample bottle containing the sample is weighed after the sample bottle is cooled to room temperature; the above heating and drying step is repeated until the mass of the sample bottle containing the sample is constant; and the wet content of the filter residue is calculated according to the mass of the sample bottle, the mass of the filter residue sample and the mass of the sample bottle containing the sample in the last time. The application can avoid the environmental corrosion problem and the ignition problem of the filter residue mixture that may occur in the wet content detection process, and can realize accurate detection of the wet content.

Description

Technical Field

[0001] This invention relates to a method for detecting the wet content of chlorosilanes and chlorosilane polymers in filter residue of a hydrogenation system, belonging to the field of detection technology for filter residue of hydrogenation systems. Background Technology

[0002] The hydrogenation system reacts silicon tetrachloride, hydrogen, and silicon powder in a fluidized bed to produce trichlorosilane, a core unit in the polysilicon production process that converts silicon tetrachloride, a byproduct, into the raw material trichlorosilane. Currently, the slag from the hydrogenation system, obtained through solid-liquid separation, consists of filter residue (particle size 0-100 μm). This residue mainly contains silicon powder, small amounts of chlorosilanes and chlorosilane polymers. The chlorosilane and chlorosilane polymer content in the filter residue, referred to as the wet content, is a crucial parameter for the next process step. Chlorosilanes and chlorosilane polymers are volatile, corrosive, and have an irritating odor. While GB / T 6284-2006 is used to determine the chlorosilane and chlorosilane polymer content in the filter residue, this standard cannot meet the requirement of achieving constant weight at 105±2℃, thus hindering accurate detection. Furthermore, it fails to address the environmental corrosion caused by the volatilization of chlorosilanes and chlorosilane polymers and the potential for ignition during sample drying. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a method for detecting the wet content of chlorosilanes and chlorosilane polymers in the filter residue of a hydrogenation system. This method can avoid environmental corrosion problems and ignition problems of the filter residue mixture that may occur during the wet content detection process, while achieving accurate detection of wet content.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0005] A method for detecting the wet content of chlorosilanes and chlorosilane polymers in filter residue of a hydrogenation system includes the following steps:

[0006] Step a: After cleaning the two-hole sample vial with cap, dry it with nitrogen gas and weigh the sample vial.

[0007] Step b: Weigh a certain mass of filter residue sample into a sample bottle;

[0008] Step c: Connect one hole of the sample bottle to the nitrogen inlet tube, where the nitrogen purity reaches 99.999% and the nitrogen flow rate is set to 45~55mL / min. Connect the other hole to one end of the tail gas tube, and insert the other end of the tail gas tube into the alkaline recovery solution. Place the sample bottle on a heating plate that has been preheated to 140~150℃ for continuous heating and drying.

[0009] Step d: After the heating plate continues to heat and dry for a period of time, the sample bottle containing the sample is cooled to room temperature and then weighed.

[0010] Step e, repeat steps c and d until the sample vial containing the sample reaches a constant weight;

[0011] Step f: Calculate the wet content of the filter residue based on the mass of the sample bottle, the mass of the filter residue sample, and the mass of the last sample bottle containing the sample.

[0012] In step c, the alkaline recovery solution is a sodium hydroxide solution.

[0013] The mass concentration of the sodium hydroxide solution is 25%~35%.

[0014] In step e, the constant weight judgment criterion is that the mass difference between two consecutive weighing values ​​is not greater than 0.01g.

[0015] In step d, the heating plate continues to heat and dry for 3.5 to 4.5 hours.

[0016] In step e, the heating plate continues to heat and dry for 25 to 35 minutes.

[0017] In step a, the sample vial is made of PFA.

[0018] In step f, the formula for calculating the wet content of the filter residue is:

[0019] ;

[0020] Where X represents the wet content of the filter residue, m0 represents the mass of the sample bottle, m1 represents the mass of the last sample bottle containing the sample, and m represents the mass of the filter residue sample.

[0021] The beneficial effects of this invention are as follows: This invention provides a method for detecting the moisture content of chlorosilanes and chlorosilane polymers in the filter residue of a hydrogenation system. The sample bottle is placed on a heating plate preheated to 140-150°C for continuous heating and drying. By precisely controlling the heating temperature, all chlorosilanes and chlorosilane polymers in the filter residue are volatilized, reaching a constant weight state, thus achieving accurate detection of moisture content. Another hole in the sample bottle is connected to one end of a tail gas pipe, the other end of which is inserted into an alkaline recovery solution. By using the alkaline solution to absorb the tail gas during the volatilization process, a closed-loop recovery of chlorosilanes and chlorosilane polymers is achieved, preventing tail gas leakage and corrosion of the surrounding environment. One hole in the sample bottle is connected to a nitrogen inlet pipe, wherein the nitrogen purity reaches 99.999%. The introduction of nitrogen provides protection against ignition of the filter residue mixture during the drying process. The nitrogen flow rate is set to 45-55 mL / min. By controlling the nitrogen flow rate, it is ensured that the dried silicon powder is not carried out by the nitrogen. Attached Figure Description

[0022] Figure 1This is a schematic diagram of the device for detecting the wet content of chlorosilanes and chlorosilane polymers in the filter residue of the hydrogenation system of the present invention.

[0023] The attached diagram is labeled as follows: 1-Nitrogen main valve; 2-Nitrogen shut-off valve; 3-Float flowmeter; 4-Sample bottle; 5-Heating plate; 6-Spare analysis end; 7-Alkali recovery solution. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present invention more clearly, and should not be used to limit the scope of protection of the present invention.

[0025] Example 1

[0026] This invention discloses a method for detecting the wet content of chlorosilanes and chlorosilane polymers in the filter residue of a hydrogenation system, comprising the following steps:

[0027] Step 1: Clean the two-hole sample vial with cap and dry it with nitrogen gas. The sample vial is made of PFA and weighs 127.55g.

[0028] Step 2: Weigh 10.06g of the filter residue sample into a sample bottle.

[0029] Step 3: Connect one port of the sample vial to a nitrogen inlet tube, with the nitrogen purity reaching 99.999% and the nitrogen flow rate set to 50 mL / min. Connect the other port to one end of a tail gas pipe, and insert the other end of the tail gas pipe into the alkaline recovery solution. Place the sample vial on a heating plate preheated to 145°C for continuous heating and drying. In this embodiment, the alkaline recovery solution is a sodium hydroxide solution with a mass concentration of 30%, prepared by dissolving 30 g of sodium hydroxide (AR) in 70 g of water.

[0030] like Figure 1 As shown, a nitrogen main valve 1 is installed on the nitrogen pipeline. The nitrogen pipeline is divided into a current analysis end and a standby analysis end 6. Both the current analysis end and the standby analysis end 6 are equipped with nitrogen shut-off valves 2 and float flow meters 3. The gas outlet pipe of the current analysis end is connected to the sample bottle 4. The sample bottle 4 is placed on the heating plate 5. Another gas outlet pipe on the sample bottle 4 is connected to the alkaline recovery solution 7.

[0031] Step 4: After the heating plate continues to heat and dry for 4.0 hours, the sample bottle containing the sample is cooled to room temperature and then weighed. The weight of the sample bottle is 137.42g.

[0032] Step 5: Repeat steps 3 and 4 until the sample vial containing the sample reaches a constant weight. The heating plate should be used for 30 minutes to maintain the drying time. The criterion for constant weight is that the difference between two consecutive weighings should not exceed 0.01g. In this example, after one repetition, the weight was 137.42g, meeting the constant weight standard.

[0033] Step 6: Calculate the wet content of the filter residue based on the mass of the sample bottle, the mass of the filter residue sample, and the mass of the last sample bottle containing the sample.

[0034] The formula for calculating the wet content of filter residue is:

[0035] ;

[0036] Where X represents the wet content of the filter residue, m0 represents the mass of the sample bottle, m1 represents the mass of the last sample bottle containing the sample, and m represents the mass of the filter residue sample. In this embodiment, the final calculated wet content of the filter residue is 1.89%.

[0037] Example 2

[0038] This invention discloses a method for detecting the wet content of chlorosilanes and chlorosilane polymers in the filter residue of a hydrogenation system, comprising the following steps:

[0039] Step 1: Clean the two-hole sample vial with cap and dry it with nitrogen gas. The sample vial is made of PFA and weighs 120.82g.

[0040] Step 2: Weigh 9.92g of the filter residue sample into a sample bottle.

[0041] Step 3: Connect one port of the sample vial to a nitrogen inlet tube, with the nitrogen purity reaching 99.999% and the nitrogen flow rate set to 45 mL / min. Connect the other port to one end of a tail gas pipe, and insert the other end of the tail gas pipe into the alkaline recovery solution. Place the sample vial on a heating plate preheated to 150°C for continuous heating and drying. In this embodiment, the alkaline recovery solution is a sodium hydroxide solution with a mass concentration of 25%, prepared by dissolving 25 g of sodium hydroxide (AR) in 75 g of water.

[0042] like Figure 1 As shown, a nitrogen main valve 1 is installed on the nitrogen pipeline. The nitrogen pipeline is divided into a current analysis end and a standby analysis end 6. Both the current analysis end and the standby analysis end 6 are equipped with nitrogen shut-off valves 2 and float flow meters 3. The gas outlet pipe of the current analysis end is connected to the sample bottle 4. The sample bottle 4 is placed on the heating plate 5. Another gas outlet pipe on the sample bottle 4 is connected to the alkaline recovery solution 7.

[0043] Step 4: After the heating plate continues to heat and dry for 4.5 hours, the sample bottle containing the sample is cooled to room temperature and then weighed. The weight of the sample bottle is 130.29g.

[0044] Step 5: Repeat steps 3 and 4 until the sample vial containing the sample reaches a constant weight. The heating plate should be used for 25 minutes to maintain the drying time. The criterion for constant weight is that the difference between two consecutive weighings should not exceed 0.01g. In this example, after one repetition, the weight was 130.29g, meeting the constant weight standard.

[0045] Step 6: Calculate the wet content of the filter residue based on the mass of the sample bottle, the mass of the filter residue sample, and the mass of the last sample bottle containing the sample.

[0046] The formula for calculating the wet content of filter residue is:

[0047] ;

[0048] Where X represents the wet content of the filter residue, m0 represents the mass of the sample bottle, m1 represents the mass of the last sample bottle containing the sample, and m represents the mass of the filter residue sample. In this embodiment, the final calculated wet content of the filter residue is 4.54%.

[0049] Example 3

[0050] This invention discloses a method for detecting the wet content of chlorosilanes and chlorosilane polymers in the filter residue of a hydrogenation system, comprising the following steps:

[0051] Step 1: Clean the two-hole sample vial with cap and dry it with nitrogen gas. The sample vial is made of PFA and weighs 131.04g.

[0052] Step 2: Weigh 10.18g of the filter residue sample into a sample bottle.

[0053] Step 3: Connect one port of the sample vial to a nitrogen inlet tube, with the nitrogen purity reaching 99.999% and the nitrogen flow rate set to 55 mL / min. Connect the other port to one end of a tail gas tube, and insert the other end of the tail gas tube into the alkaline recovery solution. Place the sample vial on a heating plate preheated to 140°C for continuous heating and drying. In this embodiment, the alkaline recovery solution is a sodium hydroxide solution with a mass concentration of 35%, prepared by dissolving 35 g of sodium hydroxide (AR) in 65 g of water.

[0054] like Figure 1As shown, a nitrogen main valve 1 is installed on the nitrogen pipeline. The nitrogen pipeline is divided into a current analysis end and a standby analysis end 6. Both the current analysis end and the standby analysis end 6 are equipped with nitrogen shut-off valves 2 and float flow meters 3. The gas outlet pipe of the current analysis end is connected to the sample bottle 4. The sample bottle 4 is placed on the heating plate 5. Another gas outlet pipe on the sample bottle 4 is connected to the alkaline recovery solution 7.

[0055] Step 4: After the heating plate continues to heat and dry for 3.5 hours, the sample bottle containing the sample is cooled to room temperature and then weighed. The weight of the sample bottle is 140.91g.

[0056] Step 5: Repeat steps 3 and 4 until the sample vial containing the sample reaches a constant weight. The heating plate should be used for 35 minutes to maintain the drying time. The criterion for constant weight is that the difference between two consecutive weighings should not exceed 0.01g. In this example, after one repetition, the weight was 140.91g, meeting the constant weight standard.

[0057] Step 6: Calculate the wet content of the filter residue based on the mass of the sample bottle, the mass of the filter residue sample, and the mass of the last sample bottle containing the sample.

[0058] The formula for calculating the wet content of filter residue is:

[0059] ;

[0060] Where X represents the moisture content of the filter residue, m0 represents the mass of the sample bottle, m1 represents the mass of the last sample bottle containing the sample, and m represents the mass of the filter residue sample. In this embodiment, the final calculated moisture content of the filter residue is 3.05%.

[0061] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for detecting the wet content of chlorosilanes and chlorosilane polymers in filter residue of a hydrogenation system, characterized in that: Includes the following steps: Step a: After cleaning the two-hole sample vial with cap, dry it with nitrogen gas and weigh the sample vial. Step b: Weigh a certain mass of filter residue sample into a sample bottle; Step c: Connect one hole of the sample bottle to the nitrogen inlet tube, where the nitrogen purity reaches 99.999% and the nitrogen flow rate is set to 45~55mL / min. Connect the other hole to one end of the tail gas tube, and insert the other end of the tail gas tube into the alkaline recovery solution. Place the sample bottle on a heating plate that has been preheated to 140~150℃ for continuous heating and drying. Step d: After the heating plate continues to heat and dry for a period of time, the sample bottle containing the sample is cooled to room temperature and then weighed. Step e, repeat steps c and d until the sample vial containing the sample reaches a constant weight; Step f: Calculate the wet content of the filter residue based on the mass of the sample bottle, the mass of the filter residue sample, and the mass of the last sample bottle containing the sample.

2. The method for detecting the wet content of chlorosilanes and chlorosilane polymers in the filter residue of the hydrogenation system according to claim 1, characterized in that: In step c, the alkaline recovery solution is a sodium hydroxide solution.

3. The method for detecting the wet content of chlorosilanes and chlorosilane polymers in the filter residue of the hydrogenation system according to claim 2, characterized in that: The mass concentration of the sodium hydroxide solution is 25%~35%.

4. The method for detecting the wet content of chlorosilanes and chlorosilane polymers in the filter residue of the hydrogenation system according to claim 1, characterized in that: In step e, the constant weight judgment criterion is that the mass difference between two consecutive weighing values ​​is not greater than 0.01g.

5. The method for detecting the wet content of chlorosilanes and chlorosilane polymers in the filter residue of the hydrogenation system according to claim 1, characterized in that: In step d, the heating plate continues to heat and dry for 3.5 to 4.5 hours.

6. The method for detecting the wet content of chlorosilanes and chlorosilane polymers in the filter residue of the hydrogenation system according to claim 1, characterized in that: In step e, the heating plate continues to heat and dry for 25 to 35 minutes.

7. The method for detecting the wet content of chlorosilanes and chlorosilane polymers in the filter residue of the hydrogenation system according to claim 1, characterized in that: In step a, the sample vial is made of PFA.

8. The method for detecting the wet content of chlorosilanes and chlorosilane polymers in the filter residue of the hydrogenation system according to claim 1, characterized in that: In step f, the formula for calculating the wet content of the filter residue is: ； Where X represents the wet content of the filter residue, m0 represents the mass of the sample bottle, m1 represents the mass of the last sample bottle containing the sample, and m represents the mass of the filter residue sample.

Images