Comprehensive utilization system and method for slag discharged by cold hydrogenation

Abstract

The invention discloses a comprehensive utilization system and method for slag discharged through cold hydrogenation, and belongs to the technical field of polycrystalline silicon production. The slag discharged through cold hydrogenation is in a settling tank, supernatant liquid enters a distillation tower to be distilled after being filtered through a filter, and part of distilled fraction enters a first rectifying tower to be rectified for the first time; and the tower kettle produced liquid of the first rectifying tower enters a second rectifying tower, the second rectifying tower performs secondary rectification, and the tower top produced liquid of the second rectifying tower is discharged through a product outlet pipe to obtain high-purity hexachlorodisilane.

Description

Technical Field

[0001] The invention belongs to the technical field of polysilicon production, and in particular relates to a comprehensive utilization system and method for slag discharged from cold hydrogenation. Background Art

[0002] At present, the production of polysilicon mainly adopts trichlorosilane reduction method and silane fluidized bed method. Both methods use industrial silicon powder, H2, hydrogen chloride and silicon tetrachloride as raw materials to produce trichlorosilane. Silicon powder reacts chemically under the action of catalyst in hydrogenation furnace to produce trichlorosilane. In this process, in addition to the generation of monosilicon chlorosilane, a small amount of disilicon or polysilicon atom chlorosilane byproducts are also generated. These byproducts are mainly removed by hydrolysis or cracked into trichlorosilane raw materials, and their value is not fully utilized.

[0003] The slag discharged from the washing tower in the production process of trichlorosilane (cold hydrogenation) is mainly composed of metal (magnesium, aluminum, iron, calcium, etc.) chlorides, trace amounts of microsilica powder, hexachlorodisilane, hexachlorodisiloxane, silicon tetrachloride, a small amount of trichlorosilane, a very small amount of methylchlorosilanes, dimethylchlorosilanes, ethylchlorosilanes, polymethylsilane, silicone oil, etc., and a very small amount of dissolved gases such as HCl, H2, N2, etc. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a comprehensive utilization system and method for slag discharged from cold hydrogenation. The slag discharged from cold hydrogenation is in a settling tank, and the supernatant liquid is filtered through a filter and then enters a distillation tower for distillation. Part of the distilled fraction enters a first distillation tower (feeding the lower part of the first distillation tower) for the first distillation, and the produced liquid from the bottom of the first distillation tower enters a second distillation tower (feeding the upper part of the second distillation tower) for the second distillation. The produced liquid from the top of the second distillation tower is discharged through a product outlet pipe to obtain high-purity hexachlorodisilane.

[0005] The objective of the present invention is achieved through the following technical solutions: A comprehensive utilization system for slag discharged by cold hydrogenation comprises a settling tank, wherein a feed pipe and a supernatant outlet pipe are arranged on the settling tank, wherein the supernatant outlet pipe is connected to a distillation tower through a filter, wherein a distillation outlet pipe is arranged on the distillation tower, wherein a first condenser is arranged on the distillation outlet pipe, wherein the distillation outlet pipe is connected to a first fractionation pipe and a second fractionation pipe, wherein a first fractionation tank and a first external discharge pump are arranged on the first fractionation pipe, wherein the second fractionation pipe is connected to a first rectification tower, wherein a first reflux assembly and a first liquid outlet pipe are arranged on the first rectification tower, wherein the first reflux assembly is connected to a chlorosilane discharge pipe, wherein the first liquid outlet pipe is connected to a second rectification tower, wherein a second reflux assembly and a second liquid outlet pipe are arranged on the second rectification tower, wherein the second reflux assembly is connected to a product outlet pipe.

[0006] Preferably, the distillation tower is provided with a first temperature control unit; and the first fractionation tank is provided with a first pressure control unit.

[0007] Preferably, the first pressure control unit includes a first pressure sensor, a first tail gas control valve, a fraction outlet pipe, a fraction pipe and a heat exchanger, the first pressure sensor is arranged on the distillation tower, the first fractionation tank is connected to the heat exchanger through the fraction outlet pipe, the heat exchanger is connected to the first fractionation tank through the fraction pipe, the heat exchanger is provided with a first tail gas outlet pipe, and the first tail gas control valve is arranged on the first tail gas outlet pipe.

[0008] Preferably, the first temperature control unit comprises a first temperature sensor, a first distillation control valve and a second distillation control valve, and the first distillation control valve and the second distillation control valve are respectively arranged on the first distillation pipe and the second distillation pipe.

[0009] Preferably, the first reflux assembly includes a first distillation outlet pipe, a first reflux tank, a first reflux pump and a first reflux pipe, the first distillation outlet pipe is provided with a second condenser, the first distillation tower is connected to the first reflux tank through the first distillation outlet pipe, the first reflux tank is connected to the first distillation tower through the first reflux pump and the first reflux pipe, and the first reflux pipe is connected to the chlorosilane discharge pipe.

[0010] Preferably, a second pressure control unit is provided on the first reflux tank, and the second pressure control unit includes a second pressure sensor, a second tail gas pipe and a second tail gas control valve, the second tail gas pipe is connected to the first reflux tank, the second pressure sensor is arranged on the first reflux tank, and the second tail gas control valve is arranged on the second tail gas pipe.

[0011] Preferably, the second reflux assembly includes a second distillation outlet pipe, a second reflux tank, a second reflux pump and a second reflux pipe, the second distillation outlet pipe is provided with a third condenser, the second distillation tower is connected to the second reflux tank via the second distillation outlet pipe, the second reflux tank is connected to the second distillation tower via the second reflux pump and the second reflux pipe, and the second reflux pipe is connected to the product outlet pipe.

[0012] Preferably, a third pressure control unit is provided on the second reflux tank, and the third pressure control unit includes a third pressure sensor, a third tail gas pipe and a third tail gas control valve. The third tail gas pipe is connected to the second reflux tank, the third pressure sensor is arranged on the second reflux tank, and the third tail gas control valve is arranged on the third tail gas pipe.

[0013] Preferably, a first slag discharge pipe is provided at the lower end of the sedimentation tank, and a second slag discharge pipe is provided at the lower end of the distillation tower, the first slag discharge pipe and the second slag discharge pipe are connected to the waste liquid tank, a third slag discharge pipe is provided at the lower end of the waste liquid tank, the third slag discharge pipe is connected to the hydrolysis tank, a water inlet pipe and a fourth slag discharge pipe are provided on the hydrolysis tank, and the fourth slag discharge pipe is connected to the wastewater treatment unit through a wastewater pump.

[0014] Preferably, the sedimentation tank, waste liquid tank and hydrolysis tank are respectively provided with a fourth pressure control unit, a fifth pressure control unit and a second temperature control unit; the fourth pressure control unit includes a fourth pressure sensor, a fourth tail gas outlet pipe and a fourth vent valve, the fourth pressure sensor and the fourth tail gas outlet pipe are both arranged on the sedimentation tank, and the fourth vent valve is arranged on the fourth tail gas outlet pipe; the fifth pressure control unit includes a fifth pressure sensor, a fifth tail gas outlet pipe and a fifth vent valve, the fifth pressure sensor and the fifth tail gas outlet pipe are both arranged on the waste liquid tank, and the fifth vent valve is arranged on the fifth tail gas outlet pipe; the second temperature control unit includes a second temperature sensor, a water inlet pipe and a water make-up valve, the second temperature sensor and the water inlet pipe are arranged on the hydrolysis tank, and the water make-up valve is arranged on the water inlet pipe.

[0015] Preferably, the first liquid outlet pipe and the second liquid outlet pipe are respectively provided with a first bottom pump and a second bottom pump.

[0016] A comprehensive utilization method for slag discharged from cold hydrogenation, comprising the following steps: Step 1, cold hydrogenation production process: the slag discharged from the washing tower enters the settling tank through the feed pipe, the slag is deposited in the settling tank, and the supernatant liquid passes through the supernatant outlet pipe and is filtered by the filter before entering the distillation tower; Step 2, the supernatant is distilled in a distillation tower, the first temperature control unit and the first pressure control unit on the distillation tower are started, the temperature of the first condenser is controlled to be less than or equal to 50°C, the first fractionation control valve is opened when the temperature on the distillation tower is less than 80°C, and the distillate flows into the first fractionation tank through the first fractionation pipe; when the temperature on the distillation tower is greater than or equal to 80°C and less than 160°C, the first fractionation control valve is closed, the second fractionation control valve is opened, and the distillate enters the first rectification tower through the second fractionation pipe; when the temperature on the distillation tower is greater than 160°C, the first fractionation control valve and the second fractionation control valve are both closed, and the distillation tower kettle material is discharged through the second slag discharge pipe; Step 3, the distillate is subjected to a primary distillation in the first distillation tower, the overhead distillate of the first distillation tower is partially refluxed to the first distillation tower through the first reflux assembly, and part of it flows into the chlorosilane raw material tank through the chlorosilane discharge pipe, and the effluent from the kettle of the first distillation tower flows into the second distillation tower through the first liquid outlet pipe; Step 4: The effluent from the bottom of the first distillation tower is subjected to secondary distillation in the second distillation tower. The top distillate of the second distillation tower is partially refluxed to the second distillation tower through the second reflux component, and partially flows out through the product outlet pipe; the effluent from the bottom of the second distillation tower flows into the settling tank through the second liquid outlet pipe.

[0017] Preferably, the first pressure control unit, the second pressure control unit and the third pressure control unit are started; when the pressure of the first distillation tank exceeds 50kpa, the first tail gas control valve is opened to discharge the tail gas from the first tail gas outlet pipe; when the pressure of the first reflux tank exceeds 150kpa, the second tail gas control valve is opened to discharge the tail gas from the second tail gas pipe; when the pressure of the second reflux tank exceeds 150kpa, the third tail gas control valve is opened to discharge the tail gas from the third tail gas pipe.

[0018] Preferably, in the step 2, the tower pressure in the distillation tower is controlled at 0-50 kPa; and the tower temperature in the distillation tower is controlled at ≤180°C.

[0019] Preferably, in step three, the tower pressure of the first distillation tower is controlled at 10-150 kPa, the tower temperature is controlled at 59-200° C., the theoretical plate is 145-200, and the reflux ratio of the first reflux assembly is 0.9-5.

[0020] Preferably, in step 4, the tower pressure of the second distillation tower is controlled at 10-150 kPa, the tower temperature is controlled at 145-200° C., the theoretical plate is 102-200, and the reflux ratio of the second reflux assembly is 4-15.

[0021] Preferably, the method further includes starting a fourth pressure control unit, a fifth pressure control unit and a second temperature control unit; discharging the bottom material of the distillation tower and the lower layer sediment in the sedimentation tank into a waste liquid tank, the waste liquid tank collects the material while stirring, and after the waste liquid tank collects the material, the material is discharged to the hydrolysis tank through the third slag discharge pipe, industrial water is added to the hydrolysis tank through the water inlet pipe, and after hydrolysis in the hydrolysis tank, it is transported to the wastewater treatment unit through the fourth slag discharge pipe and the wastewater pump; the pressure in the sedimentation tank is controlled at 10-200kpa, and the temperature of the material in the feed pipe is controlled at 30-60°C; the pressure in the waste liquid tank is controlled at 10-200kpa; the pressure in the hydrolysis tank is controlled at 10-200kpa, and the temperature in the hydrolysis tank is controlled at 20-80°C.

[0022] The beneficial effects of this technical solution are as follows: 1. The present invention provides a comprehensive utilization system for slag discharged from cold hydrogenation. The slag discharged from cold hydrogenation is in a settling tank. The supernatant is filtered through a filter and then enters a distillation tower for distillation. Part of the distilled fraction enters a first distillation tower (feeding the lower part of the first distillation tower) for the first distillation. The produced liquid from the bottom of the first distillation tower enters a second distillation tower (feeding the upper part of the second distillation tower) for the second distillation. The produced liquid from the top of the second distillation tower is discharged through a product outlet pipe to obtain high-purity hexachlorodisilane.

[0023] 2. The present invention provides a comprehensive utilization method for slag discharged from cold hydrogenation. The slag discharged from cold hydrogenation is settled in a settling tank (solid metal chlorides, fine silicon powder and other solid particles are precipitated at the bottom of the settling tank during settling and discharged regularly), and the supernatant is filtered through a filter and then enters a distillation tower. When the temperature of the distillation tower is less than 80°C, the distillation tower is switched to the first fractionation tank, and when the temperature is ≥80°C, the distillation tower is switched to the second fractionation tank. The material in the second fractionation tank is sent to the first distillation tower (feeding the lower part of the first distillation tower) for the first distillation (the first distillation removes the components with a boiling point lower than hexachlorodisilane from the top of the tower), and the produced liquid from the bottom of the first distillation tower enters the second distillation tower (feeding the upper part of the second distillation tower) for the second distillation (the second distillation removes the materials with a boiling point higher than hexachlorodisilane from the bottom of the tower), and the produced liquid from the top of the second distillation tower is discharged through the product outlet pipe to obtain high-purity hexachlorodisilane.

[0024] 3. The present invention provides a comprehensive utilization method for the slag discharged from cold hydrogenation. The distillation tower bottom material and the lower sediment in the settling tank are discharged into the waste liquid tank. The waste liquid tank is a hydrolysis buffer tank. Solid metal chlorides and silicon powder are brought into the waste liquid tank from the bottom of the settling tank by gravity and pressure difference under the flow of the liquid phase. A large amount of water is used in the hydrolysis tank to react with the materials in the settling tank. The silicon-containing materials are hydrolyzed into silicon oxide and hydrogen chloride, etc., and are sent to the environmental protection process together with silicon powder, metal chlorides, etc. for wastewater treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the present invention; In the figure: 1, sedimentation tank; 2, feed pipe; 3, supernatant outlet pipe; 4, filter; 5, distillation tower; 6, distillation outlet pipe; 7, first condenser; 8, first fractionation pipe; 9, second fractionation pipe; 10, first fractionation tank; 11, first external pump; 12, first rectification tower; 13, first reflux assembly; 131, first rectification outlet pipe; 132, first reflux tank; 133, first reflux pump; 134, first reflux pipe; 135, second condenser; 14, first liquid outlet pipe; 15, chlorosilane outlet pipe; 16, second rectification tower; 17, second reflux assembly; 171, second rectification outlet pipe; 172, second reflux tank; 173, second reflux pump; 174, second reflux pipe; 175, third condenser; 18, second liquid outlet pipe; 19, product outlet pipe; 20, first temperature control unit; 201, first temperature sensor; 202, first fractionation control valve; 203, second fractionation control valve; 21, first pressure control unit; 211, first pressure sensor; 212, first tail gas control valve ; 213, fraction outlet pipe; 214, fraction pipe; 215, heat exchanger; 216, first tail gas outlet pipe; 22, second pressure control unit; 221, second pressure sensor; 222, second tail gas pipe; 223, second tail gas control valve; 23, third pressure control unit; 231, third pressure sensor; 232, third tail gas pipe; 233, third tail gas control valve; 24, first slag discharge pipe; 25, second slag discharge pipe; 26, waste liquid tank; 27, third slag discharge pipe; 28, hydrolysis tank; 2 9. Water inlet pipe; 30. Fourth slag discharge pipe; 31. Wastewater pump; 32. Wastewater treatment unit; 33. First tower bottom pump; 34. Second tower bottom pump; 35. Fourth pressure control unit; 351. Fourth pressure sensor; 352. Fourth tail gas outlet pipe; 353. Fourth vent valve; 36. Fifth pressure control unit; 361. Fifth pressure sensor; 362. Fifth tail gas outlet pipe; 363. Fifth vent valve; 37. Second temperature control unit; 371. Second temperature sensor; 372. Water supply valve. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0027] like Figure 1As shown, a comprehensive utilization system for slag discharged by cold hydrogenation includes a settling tank 1, a feed pipe 2 and a supernatant outlet pipe 3 are arranged on the settling tank 1, the supernatant outlet pipe 3 is connected to a distillation tower 5 through a filter 4, a distillation outlet pipe 6 is arranged on the distillation tower 5, a first condenser 7 is arranged on the distillation outlet pipe 6, the distillation outlet pipe 6 is connected to a first fractionation pipe 8 and a second fractionation pipe 9, the first fractionation pipe 8 is provided with a first fractionation tank 10 and a first external discharge pump 11, the second fractionation pipe 9 is connected to a first rectification tower 12, the first rectification tower 12 is provided with a first reflux component 13 and a first liquid outlet pipe 14, the first reflux component 13 is connected to a chlorosilane outlet pipe 15, the first liquid outlet pipe 14 is connected to a second rectification tower 16, the second rectification tower 16 is provided with a second reflux component 17 and a second liquid outlet pipe 18, and the second reflux component 17 is connected to a product outlet pipe 19. The filter 4 is used in one and reserved in one, and the filter screen adopts a 40-mesh filter screen.

[0028] The distillation tower 5 is provided with a first temperature control unit 20 ; the first fractionation tank 10 is provided with a first pressure control unit 21 .

[0029] The first pressure control unit 21 includes a first pressure sensor 211, a first tail gas control valve 212, a fraction outlet pipe 213, a fraction pipe 214 and a heat exchanger 215. The first pressure sensor 211 is arranged on the distillation tower 5. The first fractionation tank 10 is connected to the heat exchanger 215 through the fraction outlet pipe 213. The heat exchanger 215 is connected to the first fractionation tank 10 through the fraction pipe 214. The heat exchanger 215 is provided with a first tail gas outlet pipe 216. The first tail gas control valve 212 is arranged on the first tail gas outlet pipe 216. The first pressure sensor 211 detects the pressure in the distillation tower 5 and transmits the pressure signal to the DCS. The DCS controls the opening or closing of the first tail gas control valve 212.

[0030] The first temperature control unit 20 includes a first temperature sensor 201, a first fractionation control valve 202, and a second fractionation control valve 203. The first fractionation control valve 202 and the second fractionation control valve 203 are respectively arranged on the first fractionation pipe 8 and the second fractionation pipe 9. The first temperature sensor 201 detects the temperature in the distillation tower 5 and transmits the temperature signal to the DCS, which controls the opening or closing of the first fractionation control valve 202 and the second fractionation control valve 203.

[0031] Among them, the first reflux component 13 includes a first distillation outlet pipe 131, a first reflux tank 132, a first reflux pump 133 and a first reflux pipe 134, the first distillation outlet pipe 131 is provided with a second condenser 135, the first distillation tower 12 is connected to the first reflux tank 132 through the first distillation outlet pipe 131, the first reflux tank 132 is connected to the first distillation tower 12 through the first reflux pump 133 and the first reflux pipe 134, and the first reflux pipe 134 is connected to the chlorosilane discharge pipe 15.

[0032] The first reflux tank 132 is provided with a second pressure control unit 22, which includes a second pressure sensor 221, a second tail gas pipe 222, and a second tail gas control valve 223. The second tail gas pipe 222 is connected to the first reflux tank 132, the second pressure sensor 221 is provided on the first reflux tank 132, and the second tail gas control valve 223 is provided on the second tail gas pipe 222. The second pressure sensor 221 detects the pressure in the first reflux tank 132, and transmits the pressure signal to the DCS, which controls the opening or closing of the second tail gas control valve 223.

[0033] Among them, the second reflux component 17 includes a second distillation outlet pipe 171, a second reflux tank 172, a second reflux pump 173 and a second reflux pipe 174, the second distillation outlet pipe 171 is provided with a third condenser 175, the second distillation tower 16 is connected to the second reflux tank 172 through the second distillation outlet pipe 171, the second reflux tank 172 is connected to the second distillation tower 16 through the second reflux pump 173 and the second reflux pipe 174, and the second reflux pipe 174 is connected to the product outlet pipe 19.

[0034] The second reflux tank 172 is provided with a third pressure control unit 23, which includes a third pressure sensor 231, a third tail gas pipe 232 and a third tail gas control valve 233. The third tail gas pipe 232 is connected to the second reflux tank 172, the third pressure sensor 231 is provided on the second reflux tank 172, and the third tail gas control valve 233 is provided on the third tail gas pipe 232. The third pressure sensor 231 detects the pressure in the second reflux tank 172, transmits the pressure signal to the DCS, and the DCS controls the opening or closing of the third tail gas control valve 233.

[0035] Among them, a first slag discharge pipe 24 is provided at the lower end of the sedimentation tank 1, and a second slag discharge pipe 25 is provided at the lower end of the distillation tower 5. The first slag discharge pipe 24 and the second slag discharge pipe 25 are connected to the waste liquid tank 26. A third slag discharge pipe 27 is provided at the lower end of the waste liquid tank 26, and the third slag discharge pipe 27 is connected to the hydrolysis tank 28. A water inlet pipe 29 and a fourth slag discharge pipe 30 are provided on the hydrolysis tank 28, and the fourth slag discharge pipe 30 is connected to the wastewater treatment unit 32 through a wastewater pump 31.

[0036] The fourth pressure control unit 35, the fifth pressure control unit 36 ​​and the second temperature control unit 37 are respectively provided on the sedimentation tank 1, the waste liquid tank 26 and the hydrolysis tank 28; the fourth pressure control unit 35 includes a fourth pressure sensor 351, a fourth tail gas outlet pipe 352 and a fourth vent valve 353, the fourth pressure sensor 351 and the fourth tail gas outlet pipe 352 are both provided on the sedimentation tank 1, and the fourth vent valve 353 is provided on the fourth tail gas outlet pipe 352; the fifth pressure control unit 35 includes a fourth pressure sensor 351, a fourth tail gas outlet pipe 352 and a fourth vent valve 353, the fourth pressure sensor 351 and the fourth tail gas outlet pipe 352 are both provided on the sedimentation tank 1, and the fourth vent valve 353 is provided on the fourth tail gas outlet pipe 352; 6 comprises a fifth pressure sensor 361, a fifth tail gas outlet pipe 362 and a fifth vent valve 363, the fifth pressure sensor 361 and the fifth tail gas outlet pipe 362 are both arranged on the waste liquid tank 26, and the fifth vent valve 363 is arranged on the fifth tail gas outlet pipe 362; the second temperature control unit 37 comprises a second temperature sensor 371, a water inlet pipe 29 and a water replenishment valve 373, the second temperature sensor 371 and the water inlet pipe 29 are arranged on the hydrolysis tank 28, and the water replenishment valve 373 is arranged on the water inlet pipe 29. The fourth pressure sensor 351, the fifth pressure sensor 361 and the second temperature sensor 371 detect the pressure of the sedimentation tank 1, the pressure of the waste liquid tank 26 and the temperature of the hydrolysis tank 28 respectively, and transmit the pressure signal of the sedimentation tank 1, the pressure signal of the waste liquid tank 26 and the temperature signal of the hydrolysis tank 28 to the DCS, and the DCS controls the opening or closing of the fourth vent valve 353, the fifth vent valve 363 and the water replenishment valve 373.

[0037] The first liquid outlet pipe 14 and the second liquid outlet pipe 18 are respectively provided with a first bottom pump 33 and a second bottom pump 34 .

[0038] A comprehensive utilization method for slag discharged from cold hydrogenation, comprising the following steps: Step 1, cold hydrogenation production process: the slag discharged from the washing tower enters the settling tank 1 through the feed pipe 2, the slag is deposited in the settling tank 1, and the supernatant liquid passes through the supernatant outlet pipe 3 and is filtered by the filter 4 and then enters the distillation tower 5; Step 2, the supernatant is distilled in the distillation tower 5, the first temperature control unit 20 and the first pressure control unit 21 on the distillation tower 5 are started, the temperature of the first condenser 7 is controlled to be less than or equal to 50°C, when the temperature on the distillation tower 5 is less than 80°C, the first fractionation control valve 202 is opened, and the distillate flows into the first fractionation tank 10 through the first fractionation pipe 8; when the temperature on the distillation tower 5 is greater than or equal to 80°C and less than 160°C, the first fractionation control valve 202 is closed, the second fractionation control valve 203 is opened, and the distillate flows into the first distillation tower 12 through the second fractionation pipe 9; when the temperature on the distillation tower 5 is greater than 160°C, the first fractionation control valve 202 and the second fractionation control are both closed, and the kettle material of the distillation tower 5 is discharged through the second slag discharge pipe 25; Step 3, the distillate is subjected to a primary distillation in the first distillation tower 12, the top distillate of the first distillation tower 12 is partially refluxed to the first distillation tower 12 through the first reflux assembly 13, and partially flows into the chlorosilane raw material tank through the chlorosilane discharge pipe 15, and the effluent from the bottom of the first distillation tower 12 flows into the second distillation tower 16 through the first liquid outlet pipe 14; Step 4: The effluent from the bottom of the first distillation tower 12 is subjected to secondary distillation in the second distillation tower 16. The top distillate of the second distillation tower 16 is partially refluxed to the second distillation tower 16 through the second reflux assembly 17, and partially flows out through the product outlet pipe 19; the effluent from the bottom of the second distillation tower 16 flows into the settling tank 1 through the second liquid outlet pipe 18.

[0039] Among them, it also includes the start-up of the first pressure control unit 21, the second pressure control unit 22 and the third pressure control unit 23; when the pressure of the first distillation tank 10 exceeds 50kpa, the first tail gas control valve 212 is opened to discharge the tail gas from the first tail gas outlet pipe 216; when the pressure of the first reflux tank 132 exceeds 150kpa, the second tail gas control valve 223 is opened to discharge the tail gas from the second tail gas pipe 222; when the pressure of the second reflux tank 172 exceeds 150kpa, the third tail gas control valve 233 is opened to discharge the tail gas from the third tail gas pipe 232.

[0040] Wherein, in the step 2, the tower pressure in the distillation tower 5 is controlled at 0-50 kPa; and the tower temperature in the distillation tower 5 is controlled at ≤180°C.

[0041] Wherein, in the step three, the tower pressure of the first distillation tower 12 is controlled at 10-150 kPa, the tower temperature is controlled at 59-200° C., the theoretical plate is 145-200, and the reflux ratio of the first reflux component 13 is 0.9-5.

[0042] Wherein, in the step 4, the tower pressure of the second distillation tower 16 is controlled at 10-150 kPa, the tower temperature is controlled at 145-200° C., the theoretical plate is 102-200, and the reflux ratio of the second reflux component 17 is 4-15.

[0043] The method further includes starting the fourth pressure control unit 35, the fifth pressure control unit 36 ​​and the second temperature control unit 37; the kettle material of the distillation tower 5 and the lower sediment in the sedimentation tank 1 are discharged into the waste liquid tank 26, the waste liquid tank 26 collects the material while stirring, and after collecting the material, the waste liquid tank 26 discharges the material to the hydrolysis tank 28 through the third slag discharge pipe 27, and industrial water is added to the hydrolysis tank 28 through the water inlet pipe 29, and after hydrolysis in the hydrolysis tank 28, it is transported to the wastewater treatment unit 32 through the fourth slag discharge pipe 30 and the wastewater pump 31; the pressure in the sedimentation tank 1 is controlled at 10-200kpa, and the temperature of the material in the feed pipe 2 is controlled at 30-60℃; the pressure in the waste liquid tank 26 is controlled at 10-200kpa; the pressure in the hydrolysis tank 28 is controlled at 10-200kpa, and the temperature in the hydrolysis tank 28 is controlled at 20-80℃.

[0044] Example 1 In this embodiment, the temperature of the material in the feed pipe 2 is controlled at 30-40°C; the pressure in the settling tank 1 is controlled at 10-20kpa; the tower pressure in the distillation tower 5 is controlled at 0-10kpa; the temperature of the first condenser 7 is controlled at less than or equal to 50°C; when the tower temperature in the distillation tower 5 is less than 80°C, the distillate flows into the first fractionation tank 10 through the first fractionation pipe 8, and the contents of each component in the first fractionation tank 10 are chlorosilane>95%, methyl and ethyl chlorosilanes<2%, and hexachlorodisilane<2%; when the tower temperature in the distillation tower 5 is ≥80°C, the distillate enters the first distillation tower 12 through the second fractionation pipe 9 for the first distillation; the tower of the first distillation tower 12 The pressure is controlled at 10-20 kPa, the tower temperature is controlled at 59-165°C, the theoretical plate is 200, and the reflux ratio of the first reflux component 13 is 0.9; the effluent from the bottom of the first distillation tower 12 flows into the second distillation tower 16 through the first liquid outlet pipe 14 for the second distillation; the tower pressure of the second distillation tower 16 is controlled at 10-20 kPa, the tower temperature is controlled at 145-168°C, the theoretical plate is 200, and the reflux ratio of the second reflux component 17 is 4; the top distillate of the second distillation tower 16 is partially refluxed to the second distillation tower 16 through the second reflux component 17, and partially flows out through the product outlet pipe 19, and the purity of hexachlorodisilane in the product is greater than 99.9% (better than the purity requirement of GB / T42720-2023 "Electronic Special Gas Hexachlorodisilane"), and contains trace ppm-level hexachlorodisiloxane and ppt-level silicone oil impurities.

[0045] The kettle material of the distillation tower 5 is discharged into the waste liquid tank 26, and the waste liquid tank 26 collects the material while stirring. After collecting the material, the waste liquid tank 26 discharges the material to the hydrolysis tank 28 through the third slag discharge pipe 27. Industrial water is added to the hydrolysis tank 28 through the water inlet pipe 29. After hydrolysis in the hydrolysis tank 28, it is transported to the wastewater treatment unit 32 through the fourth slag discharge pipe 30 and the wastewater pump 31; the pressure in the waste liquid tank 26 is controlled at 10-20kpa; the pressure in the hydrolysis tank 28 is controlled at 10-20kpa; the temperature in the hydrolysis tank 28 is controlled at 30-40℃.

[0046] Example 2 In this embodiment, the temperature of the material in the feed pipe 2 is controlled at 30-40°C; the pressure in the settling tank 1 is controlled at 10-20kpa; the tower pressure in the distillation tower 5 is controlled at 10-15kpa; the temperature of the first condenser 7 is controlled at less than or equal to 50°C; when the tower temperature in the distillation tower 5 is less than 80°C, the distillate flows into the first fractionation tank 10 through the first fractionation pipe 8, and the contents of each component in the first fractionation tank 10 are respectively chlorosilane>95%, methyl and ethyl chlorosilanes<2%, and hexachlorodisilane<2%; when the tower temperature in the distillation tower 5 is ≥80°C, the distillate enters the first distillation tower 12 through the second fractionation pipe 9 for the first distillation; the first fractionation The tower pressure of the distillation tower 12 is controlled at 10-20 kpa, the tower temperature is controlled at 59-165° C., the theoretical plate is 200, and the reflux ratio of the first reflux component 13 is 1.5; the effluent from the bottom of the first distillation tower 12 flows into the second distillation tower 16 through the first liquid outlet pipe 14 for a second distillation; the tower pressure of the second distillation tower 16 is controlled at 10-20 kpa, the tower temperature is controlled at 145-168° C., the theoretical plate is 200, and the reflux ratio of the second reflux component 17 is 5; the top distillate of the second distillation tower 16 is partially refluxed to the second distillation tower 16 through the second reflux component 17, and partially flows out through the product outlet pipe 19, and the purity of hexachlorodisilane in the product is greater than 99.9% (better than the purity requirement of GB / T 42720-2023 "Electronic Special Gas Hexachlorodisilane"), and contains trace ppm-level hexachlorodisiloxane and ppt-level silicone oil impurities.

[0047] The kettle material of the distillation tower 5 is discharged into the waste liquid tank 26, and the waste liquid tank 26 collects the material while stirring. After collecting the material, the waste liquid tank 26 discharges the material to the hydrolysis tank 28 through the third slag discharge pipe 27. Industrial water is added to the hydrolysis tank 28 through the water inlet pipe 29. After being hydrolyzed in the hydrolysis tank 28, it is transported to the wastewater treatment unit 32 through the fourth slag discharge pipe 30 and the wastewater pump 31; the pressure in the waste liquid tank 26 is controlled at 100-110kpa; the pressure in the hydrolysis tank 28 is controlled at 100-110kpa; the temperature in the hydrolysis tank 28 is controlled at 40-50℃.

[0048] Example 3 In this embodiment, the temperature of the material in the feed pipe 2 is controlled at 30-40°C; the pressure in the settling tank 1 is controlled at 60-80kpa; the tower pressure in the distillation tower 5 is controlled at 15-20kpa; the temperature of the first condenser 7 is controlled at less than or equal to 50°C; when the tower temperature in the distillation tower 5 is less than 80°C, the distillate flows into the first fractionation tank 10 through the first fractionation pipe 8; when the tower temperature in the distillation tower 5 is ≥80°C, the distillate enters the first distillation tower 12 through the second fractionation pipe 9 for the first distillation; the tower pressure of the first distillation tower 12 is controlled at 10-20kpa, and the tower temperature is controlled at 59-165℃, 200 theoretical plates, and a reflux ratio of 2 for the first reflux component 13; the effluent from the bottom of the first distillation tower 12 flows into the second distillation tower 16 through the first liquid outlet pipe 14 for a second distillation; the tower pressure of the second distillation tower 16 is controlled at 10-20kPa, the tower temperature is controlled at 145-168℃, 200 theoretical plates, and the reflux ratio of 7 for the second reflux component 17; the top distillate of the second distillation tower 16 is partially refluxed to the second distillation tower 16 through the second reflux component 17, and partially flows out through the product outlet pipe 19, and the purity of hexachlorodisilane in the product is ≥99.9% (better than the purity requirement of GB / T 42720-2023 "Electronic Special Gas Hexachlorodisilane"), and contains trace ppm-level hexachlorodisiloxane and ppt-level silicone oil impurities.

[0049] The contents of the distillation tower 5 are discharged into the waste liquid tank 26, which collects the contents while stirring. After collecting the contents, the waste liquid tank 26 discharges the contents into the hydrolysis tank 28 through the third slag discharge pipe 27. Industrial water is added into the hydrolysis tank 28 through the water inlet pipe 29, and after being hydrolyzed in the hydrolysis tank 28, it is transported to the waste water treatment unit 32 through the fourth slag discharge pipe 30 and the waste water pump 31. The pressure in the waste liquid tank 26 is controlled at 180-200 kPa. The pressure in the hydrolysis tank 28 is controlled at 180-200 kPa. The temperature in the hydrolysis tank 28 is controlled at 70-80°C.

[0050] Example 4 The difference between this embodiment and embodiment 3 is that the temperature of the material in the feed pipe 2 is controlled at 40-50°C; the pressure in the settling tank 1 is controlled at 20-30kPa; the tower pressure in the distillation tower 5 is controlled at 20-30kPa; the temperature of the first condenser 7 is controlled at less than or equal to 50°C; when the tower temperature in the distillation tower 5 is less than 80°C, the distillate flows into the first fractionation tank 10 through the first fractionation pipe 8; when the tower temperature in the distillation tower 5 is ≥80°C, the distillate enters the first distillation tower 12 through the second fractionation pipe 9 for the first distillation; the tower pressure of the first distillation tower 12 is controlled at 110-120kPa, The tower temperature is controlled at 80-192°C, the theoretical plate is 180, and the reflux ratio of the first reflux component 13 is 3; the effluent from the bottom of the first distillation tower 12 flows into the second distillation tower 16 through the first liquid outlet pipe 14 for the second distillation; the tower pressure of the second distillation tower 16 is controlled at 110-120kpa, the tower temperature is controlled at 172-192°C, the theoretical plate is 150, and the reflux ratio of the second reflux component 17 is 9; the top distillate of the second distillation tower 16 is partially refluxed to the second distillation tower 16 through the second reflux component 17, and partially flows out through the product outlet pipe 19, and the purity of hexachlorodisilane in the product is greater than 99.9% (better than the purity requirement of GB / T 42720-2023 "Electronic Special Gas Hexachlorodisilane"), and contains trace ppm-level hexachlorodisiloxane and ppt-level silicone oil impurities.

[0051] Example 5 The difference between this embodiment and embodiment 3 is that the temperature of the material in the feed pipe 2 is controlled at 50-60°C; the pressure in the settling tank 1 is controlled at 30-40kPa; the tower pressure in the distillation tower 5 is controlled at 30-40kPa; the temperature of the first condenser 7 is controlled at less than or equal to 50°C; when the tower temperature in the distillation tower 5 is less than 80°C, the distillate flows into the first fractionation tank 10 through the first fractionation pipe 8; when the tower temperature in the distillation tower 5 is ≥80°C, the distillate enters the first distillation tower 12 through the second fractionation pipe 9 for the first distillation; the tower pressure of the first distillation tower 12 is controlled at 140-150kPa, and the tower The temperature is controlled at 85-200°C, the theoretical plate is 145, and the reflux ratio of the first reflux component 13 is 4; the effluent from the bottom of the first distillation tower 12 flows into the second distillation tower 16 through the first liquid outlet pipe 14 for the second distillation; the tower pressure of the second distillation tower 16 is controlled at 130-150kpa, the tower temperature is controlled at 175-200°C, the theoretical plate is 102, and the reflux ratio of the second reflux component 17 is 12; the top distillate of the second distillation tower 16 is partially refluxed to the second distillation tower 16 through the second reflux component 17, and partially flows out through the product outlet pipe 19, and the purity of hexachlorodisilane in the product is greater than 99.9% (better than the purity requirement of GB / T 42720-2023 "Electronic Special Gas Hexachlorodisilane"), and contains trace amounts of ppm-level hexachlorodisiloxane and ppt-level silicone oil and other impurities.

[0052] Example 6 In this embodiment, the temperature of the material in the feed pipe 2 is controlled at 50-60°C; the pressure in the settling tank 1 is controlled at 80-100kpa; the tower pressure in the distillation tower 5 is controlled at 40-50kpa; when the tower temperature in the distillation tower 5 is less than 80°C, the distillate flows into the first fractionation tank 10 through the first fractionation pipe 8; when the tower temperature in the distillation tower 5 is ≥80°C, the distillate enters the first distillation tower 12 through the second fractionation pipe 9 for the first distillation; the tower pressure of the first distillation tower 12 is controlled at 140-150kpa, and the tower temperature is controlled at 85-200°C, theoretically Plate 145, the reflux ratio of the first reflux component 13 is 5; the effluent from the bottom of the first distillation tower 12 flows into the second distillation tower 16 through the first liquid outlet pipe 14 for the second distillation; the tower pressure of the second distillation tower 16 is controlled at 130-150kpa, the tower temperature is controlled at 175-200℃, theoretical plate 102, the reflux ratio of the second reflux component 17 is 15; the top distillate of the second distillation tower 16 is partially refluxed to the second distillation tower 16 through the second reflux component 17, and partially flows out through the product outlet pipe 19, the purity of hexachlorodisilane in the product is>99.9% (better than the purity requirement of GB / T 42720-2023 "Electronic Special Gas Hexachlorodisilane"), and contains trace ppm-level hexachlorodisiloxane and ppt-level silicone oil and other impurities.

[0053] The tower temperature in the distillation tower 5 is controlled to be greater than 160°C; the kettle material of the distillation tower 5 is discharged through the second slag discharge pipe 25; the kettle material of the distillation tower 5 and the lower layer of sediment in the sedimentation tank 1 are discharged into the waste liquid tank 26, the waste liquid tank 26 collects the material while stirring, and after the waste liquid tank 26 collects the material, the material is discharged to the hydrolysis tank 28 through the third slag discharge pipe 27, and industrial water is added to the hydrolysis tank 28 through the water inlet pipe 29, and after being hydrolyzed in the hydrolysis tank 28, it is transported to the wastewater treatment unit 32 through the fourth slag discharge pipe 30 and the wastewater pump 31; the pressure in the waste liquid tank 26 is controlled at 180-200kpa; the pressure in the hydrolysis tank 28 is controlled at 180-200kpa; the temperature in the hydrolysis tank 28 is controlled at 70-80°C.

[0054] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A comprehensive utilization system for slag discharged from cold hydrogenation, characterized in that: The invention comprises a settling tank (1), wherein a feed pipe (2) and a supernatant outlet pipe (3) are arranged on the settling tank (1), wherein the supernatant outlet pipe (3) is connected to a distillation tower (5) via a filter (4), wherein a distillation outlet pipe (6) is arranged on the distillation tower (5), wherein a first condenser (7) is arranged on the distillation outlet pipe (6), wherein the distillation outlet pipe (6) is connected to a first fractionation pipe (8) and a second fractionation pipe (9), wherein a first fractionation tank (10) and a first external discharge pump (11) are arranged on the first fractionation pipe (8), wherein the first fractionation pipe (8) is provided with a first fractionation tank (10) and a first external discharge pump (11), wherein the first fractionation pipe (8) is provided with a first fractionation tank (10) and a first external discharge pump (11), wherein the first fractionation pipe (8) is provided with a first fractionation tank (10) and a first fractionation tank (10) and a first fractionation tank (11) are connected to the first fractionation pipe (8), wherein the first fractionation pipe (8) is provided with a first fractionation tank (10) and a first fractionation tank (1 ...) and the first fractionation tank (10) and the first fractionation tank (1 The second fractionating pipe (9) is connected to the first distillation tower (12); the first distillation tower (12) is provided with a first reflux component (13) and a first liquid outlet pipe (14); the first reflux component (13) is connected to the chlorosilane outlet pipe (15); the first liquid outlet pipe (14) is connected to the second distillation tower (16); the second distillation tower (16) is provided with a second reflux component (17) connected to the second liquid outlet pipe (18); the second reflux component (17) is connected to the product outlet pipe (19).

2. A comprehensive utilization system for slag discharged from cold hydrogenation according to claim 1, characterized in that: The distillation tower (5) is provided with a first temperature control unit (20); and the first fractionation tank (10) is provided with a first pressure control unit (21).

3. A comprehensive utilization system for slag discharged from cold hydrogenation according to claim 2, characterized in that: The first pressure control unit (21) comprises a first pressure sensor (211), a first tail gas control valve (212), a fraction outlet pipe (213), a fraction pipe (214) and a heat exchanger (215); the first pressure sensor (211) is arranged on the distillation tower (5); the first fractionation tank (10) is connected to the heat exchanger (215) via the fraction outlet pipe (213); the heat exchanger (215) is connected to the first fractionation tank (10) via the fraction pipe (214); the heat exchanger (215) is provided with a first tail gas outlet pipe (216); and the first tail gas control valve (212) is arranged on the first tail gas outlet pipe (216).

4. A comprehensive utilization system for slag discharged from cold hydrogenation according to claim 3, characterized in that: The first temperature control unit (20) comprises a first temperature sensor (201), a first fractionation control valve (202) and a second fractionation control valve (203); the first fractionation control valve (202) and the second fractionation control valve (203) are respectively arranged on a first fractionation tube (8) and a second fractionation tube (9).

5. The comprehensive utilization system for slag discharged from cold hydrogenation according to claim 1, characterized in that: The first reflux component (13) comprises a first rectification outlet pipe (131), a first reflux tank (132), a first reflux pump (133) and a first reflux pipe (134); the first rectification outlet pipe (131) is provided with a second condenser (135); the first rectification tower (12) is connected to the first reflux tank (132) via the first rectification outlet pipe (131); the first reflux tank (132) is connected to the first rectification tower (12) via the first reflux pump (133) and the first reflux pipe (134); and the first reflux pipe (134) is connected to a chlorosilane discharge pipe (15).

6. A comprehensive utilization system for slag discharged from cold hydrogenation according to claim 5, characterized in that: The first reflux tank (132) is provided with a second pressure control unit (22), the second pressure control unit (22) comprising a second pressure sensor (221), a second tail gas pipe (222) and a second tail gas control valve (223), the second tail gas pipe (222) being connected to the first reflux tank (132), the second pressure sensor (221) being provided on the first reflux tank (132), and the second tail gas control valve (223) being provided on the second tail gas pipe (222).

7. The comprehensive utilization system for slag discharged from cold hydrogenation according to claim 1, characterized in that: The second reflux component (17) comprises a second rectification outlet pipe (171), a second reflux tank (172), a second reflux pump (173) and a second reflux pipe (174); a third condenser (175) is arranged on the second rectification outlet pipe (171); the second rectification tower (16) is connected to the second reflux tank (172) via the second rectification outlet pipe (171); the second reflux tank (172) is connected to the second rectification tower (16) via the second reflux pump (173) and the second reflux pipe (174); and the second reflux pipe (174) is connected to the product outlet pipe (19).

8. A comprehensive utilization system for slag discharged from cold hydrogenation according to claim 7, characterized in that: The second reflux tank (172) is provided with a third pressure control unit (23), the third pressure control unit (23) comprising a third pressure sensor (231), a third tail gas pipe (232) and a third tail gas control valve (233), the third tail gas pipe (232) being connected to the second reflux tank (172), the third pressure sensor (231) being provided on the second reflux tank (172), and the third tail gas control valve (233) being provided on the third tail gas pipe (232).

9. The comprehensive utilization system for slag discharged from cold hydrogenation according to claim 1, characterized in that: A first slag discharge pipe (24) is provided at the lower end of the settling tank (1), and a second slag discharge pipe (25) is provided at the lower end of the distillation tower (5). The first slag discharge pipe (24) and the second slag discharge pipe (25) are connected to a waste liquid tank (26). A third slag discharge pipe (27) is provided at the lower end of the waste liquid tank (26). The third slag discharge pipe (27) is connected to a hydrolysis tank (28). A water inlet pipe (29) and a fourth slag discharge pipe (30) are provided on the hydrolysis tank (28). The fourth slag discharge pipe (30) is connected to a waste water treatment unit (32) via a waste water pump (31).

10. A comprehensive utilization system for slag discharged from cold hydrogenation according to claim 9, characterized in that: The settling tank (1), the waste liquid tank (26) and the hydrolysis tank (28) are respectively provided with a fourth pressure control unit (35), a fifth pressure control unit (36) and a second temperature control unit (37); the fourth pressure control unit (35) comprises a fourth pressure sensor (351), a fourth tail gas outlet pipe (352) and a fourth vent valve (353); the fourth pressure sensor (351) and the fourth tail gas outlet pipe (352) are both provided on the settling tank (1); the fourth vent valve (353) is provided on the fourth tail gas outlet pipe (352); the fifth pressure control unit (351) comprises a fourth pressure sensor (351), a fourth tail gas outlet pipe (352) and a fourth vent valve (353); the fourth pressure sensor (351) and the fourth tail gas outlet pipe (352) are both provided on the settling tank (1); the fourth vent valve (353) is provided on the fourth tail gas outlet pipe (352); 6) comprising a fifth pressure sensor (361), a fifth tail gas outlet pipe (362) and a fifth vent valve (363), wherein the fifth pressure sensor (361) and the fifth tail gas outlet pipe (362) are both arranged on the waste liquid tank (26), and the fifth vent valve (363) is arranged on the fifth tail gas outlet pipe (362); the second temperature control unit (37) comprises a second temperature sensor (371) and a water replenishment valve (372), the second temperature sensor (371) and the water inlet pipe (29) are arranged on the hydrolysis tank (28), and the water replenishment valve (372) is arranged on the water inlet pipe (29).

11. The comprehensive utilization system for slag discharged from cold hydrogenation according to claim 1, characterized in that: The first liquid outlet pipe (14) and the second liquid outlet pipe (18) are respectively provided with a first tower bottom pump (33) and a second tower bottom pump (34).

12. A comprehensive utilization method for slag discharged from cold hydrogenation, characterized in that: The following steps are involved: Step 1: The slag discharged from the washing tower in the cold hydrogenation production process enters the settling tank (1) through the feed pipe (2), the slag is deposited in the settling tank (1), and the supernatant liquid passes through the supernatant outlet pipe (3), is filtered through the filter (4), and then enters the distillation tower (5); Step 2: The supernatant liquid is distilled in a distillation tower (5), the first temperature control unit (20) and the first pressure control unit (21) on the distillation tower (5) are started, the temperature of the first condenser (7) is controlled to be less than or equal to 50°C, and the first fractionation control valve (202) is opened before the temperature on the distillation tower (5) is less than 80°C, and the distillate enters the first fractionation tank (10) through the first fractionation pipe (8); when the temperature on the distillation tower (5) is greater than or equal to 80°C and less than 160°C, the first fractionation control valve (202) is closed, the second fractionation control valve (203) is opened, and the distillate enters the first rectification tower (12) through the second fractionation pipe (9); when the temperature on the distillation tower (5) is greater than 160°C, both the first fractionation control valve (202) and the second fractionation control valve are closed, and the kettle material of the distillation tower (5) is discharged through the second slag discharge pipe (25); Step 3: the distillate is subjected to a primary distillation in the first distillation tower (12); the distillate from the top of the first distillation tower (12) is partially refluxed to the first distillation tower (12) through the first reflux assembly (13), and partially flows into the chlorosilane raw material tank through the chlorosilane discharge pipe (15); the effluent from the bottom of the first distillation tower (12) flows into the second distillation tower (16) through the first liquid outlet pipe (14); Step 4: The bottom effluent of the first distillation tower (12) is subjected to secondary distillation in the second distillation tower (16); the top distillate of the second distillation tower (16) is partially refluxed to the second distillation tower (16) through the second reflux assembly (17), and partially flows out through the product outlet pipe (19); the bottom effluent of the second distillation tower (16) flows into the settling tank (1) through the second liquid outlet pipe (18).

13. A comprehensive utilization method for slag discharged from cold hydrogenation according to claim 12, characterized in that: It also includes a first pressure control unit (21), a second pressure control unit (22) and a third pressure control unit (23); when the pressure of the first fractionation tank (10) exceeds 50 kPa, the first tail gas control valve (212) is opened to discharge the tail gas from the first tail gas outlet pipe (216); when the pressure of the first reflux tank (132) exceeds 150 kPa, the second tail gas control valve (223) is opened to discharge the tail gas from the second tail gas pipe (222); when the pressure of the second reflux tank (172) exceeds 150 kPa, the third tail gas control valve (233) is opened to discharge the tail gas from the third tail gas pipe (232).

14. The comprehensive utilization method of slag discharged from cold hydrogenation according to claim 12, characterized in that: In the step 2, the tower pressure in the distillation tower (5) is controlled at 0-50 kPa; and the tower temperature in the distillation tower (5) is controlled at ≤180°C.

15. The comprehensive utilization method of slag discharged from cold hydrogenation according to claim 12, characterized in that: In the step 3, the tower pressure of the first distillation tower (12) is controlled at 10-150 kPa, the tower temperature is controlled at 59-200°C, the theoretical plate is 145-200, and the reflux ratio of the first reflux component (13) is 0.9-5.

16. The method for comprehensive utilization of slag discharged from cold hydrogenation according to claim 12, characterized in that: In the step 4, the tower pressure of the second distillation tower (16) is controlled at 10-150 kPa, the tower temperature is controlled at 145-200°C, the theoretical plate is 102-200, and the reflux ratio of the second reflux component (17) is 4-15.

17. The method for comprehensive utilization of slag discharged from cold hydrogenation according to claim 12, characterized in that: The method further includes starting a fourth pressure control unit (35), a fifth pressure control unit (36) and a second temperature control unit (37); discharging the kettle material of the distillation tower (5) and the lower layer sediment in the sedimentation tank (1) into a waste liquid tank (26); the waste liquid tank (26) collecting the material while stirring; after collecting the material, the waste liquid tank (26) discharges the material into a hydrolysis tank (28) through a third slag discharge pipe (27); industrial water is added into the hydrolysis tank (28) through a water inlet pipe (29); after being hydrolyzed in the hydrolysis tank (28), it is transported to a waste water treatment unit (32) through a fourth slag discharge pipe (30) and a waste water pump (31).

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