Crude sulfur refining system and method

Abstract

The invention discloses a crude sulfur refining system and method, and belongs to the technical field of hazardous waste recycling. The system comprises a crude sulfur pretreatment unit used for removing water-soluble inorganic salt, water and waste gas in crude sulfur to form pretreated dry sulfur solid; the first extraction unit is used for extracting a first extract containing coal tar from the dry sulfur solid and separating out a first raffinate; the first extraction agent recovery unit is used for separating a first recovery extraction agent and coal tar from the first extract; the second extraction unit is used for extracting a second extract from the first raffinate and separating a second raffinate; and the second extraction agent recovery unit is used for separating sulfur and a second recovery extraction agent from the second extract. The refined sulfur obtained by the refining system and method meets the national standard requirements, and can effectively reduce the harm of hazardous wastes to the environment and realize resource recycling to the greatest extent.

Description

Technical Field

[0001] The present application relates to the technical field of hazardous waste resource recovery, and more specifically, to a crude sulfur refining system and method. Background Art

[0002] Sulfur recovered by chemical companies is the main source of domestic sulfur, including coking plants and fertilizer plants. The process is a wet desulfurization process. When the wet method is used to desulfurize coke oven gas, the sulfur foam obtained by flotation regeneration of the desulfurization liquid contains not only sulfur, but also hydrocarbon components containing tar and naphthalene, desulfurizers, desulfurization by-salts and other trace impurities. At present, companies using wet catalytic oxidation generally send sulfur containing impurities to downstream companies for further comprehensive utilization, but these crude sulfur cannot be effectively treated. The new solid waste law defines sulfur containing impurities as hazardous waste. How to purify and recycle crude sulfur has become a problem facing this field. Summary of the invention

[0003] The main purpose of the present application is to provide a crude sulfur refining system and method to solve the problem that crude sulfur cannot be effectively purified and recycled in the prior art.

[0004] In order to achieve the above object, according to one aspect of the present application, a crude sulfur refining system is provided, comprising:

[0005] A crude sulfur pretreatment unit has a crude sulfur inlet, a water inlet and a pretreated solid outlet; the crude sulfur pretreatment unit is used to remove water-soluble inorganic salts, water and waste gas in the crude sulfur to form pretreated dry sulfur solids;

[0006] The first extraction unit has a pretreated solid inlet, a first extractant inlet, a first extraction phase outlet and a first raffinate phase outlet; the pretreated solid outlet is connected to the pretreated solid inlet; the first extraction unit is used to extract a first extract containing coal tar from the pretreated dry sulfur solid and separate a first raffinate containing sulfur;

[0007] A first extractant recovery unit has a first extraction phase inlet, a first recovery extractant outlet and a coal tar outlet; the first extraction phase outlet is connected to the first extraction phase inlet; the first extractant recovery unit is used to separate the first recovery extractant and coal tar from the first extract containing coal tar;

[0008] The second extraction unit has a first raffinate phase inlet, a second extractant inlet, a second extract phase outlet and a second raffinate phase outlet; the first raffinate phase outlet is connected to the first raffinate phase inlet; the second extraction unit is used to extract a second extract containing sulfur from the first raffinate containing sulfur and separate the second raffinate;

[0009] The second extractant recovery unit has a second extraction phase inlet, a second recovery extractant outlet and a sulfur outlet; the second extraction phase outlet is connected to the second extraction phase inlet; the second extractant recovery unit is used to separate sulfur and the second recovery extractant from the sulfur-containing second extract, and the sulfur is refined sulfur.

[0010] Further, the crude sulfur pretreatment unit includes a water washing unit, a first solid-liquid separation unit and a drying and dehydration unit;

[0011] The water washing unit has a crude sulfur inlet, a water inlet and a water-washed material outlet; the water washing unit is used to remove water-soluble inorganic salts in the crude sulfur to form a water-washed material;

[0012] The first solid-liquid separation unit has a washed material inlet, a wastewater outlet and a first sulfur-containing solid outlet; the washed material outlet is connected to the washed material inlet; the first solid-liquid separation unit is used to separate the wastewater and the first sulfur-containing solid in the washed material;

[0013] The drying and dehydration unit has a first sulfur-containing solid inlet, a pretreated solid outlet and a waste gas outlet; the first sulfur-containing solid outlet is connected to the first sulfur-containing solid inlet; the drying and dehydration unit is used to remove moisture and waste gas from the first sulfur-containing solid to form pretreated dry sulfur solid.

[0014] Further, the refining system also includes a distilled water storage unit, a wastewater treatment unit and a waste gas treatment unit;

[0015] The outlet of the distilled water storage unit is connected to the water inlet; the wastewater outlet is connected to the inlet of the wastewater treatment unit, the liquid outlet of the wastewater treatment unit is connected to the inlet of the distilled water storage unit, and the solid outlet of the wastewater treatment unit is used to send out the treated waste salt;

[0016] The exhaust gas outlet is connected to the inlet of the exhaust gas treatment unit, and the exhaust gas treatment unit is used to discharge the exhaust gas that meets the standards after treatment;

[0017] The wastewater treatment unit includes a multiple-effect evaporator and a mechanical vapor recompression unit.

[0018] Further, the refining system also includes a first extractant storage unit and a second extractant storage unit;

[0019] The first extractant storage unit has a first extractant supply inlet, a first extractant recovery inlet and a first extractant outlet; the first extractant outlet is connected to the first extractant inlet; the first extractant recovery outlet is connected to the first extractant recovery inlet;

[0020] The second extractant storage unit has a second extractant supply inlet, a second extractant recovery inlet, and a second extractant outlet; the second extractant outlet is connected to the second extractant inlet; and the second extractant recovery outlet is connected to the second extractant recovery inlet.

[0021] Furthermore, the refining system also includes a second solid-liquid separation unit, having a second raffinate phase inlet, a second separation liquid outlet and a second separation solid outlet; the second raffinate phase outlet is connected to the second raffinate phase inlet; the first extraction unit also has a second separation liquid inlet; the second separation liquid outlet is connected to the second separation liquid inlet.

[0022] Furthermore, the second solid-liquid separation unit includes a plate and frame filter press and / or a belt filter.

[0023] Further, the first extraction unit includes an extraction tower.

[0024] Further, the second extraction unit includes an extraction tower.

[0025] Furthermore, the first extractant recovery unit includes a distillation tower.

[0026] Furthermore, the second extractant recovery unit includes a temperature reduction crystallization device.

[0027] Furthermore, the first solid-liquid separation unit includes a plate and frame filter press and / or a belt filter.

[0028] Further, the drying and dehydration unit includes a vacuum dryer.

[0029] According to a second aspect of the present application, a crude sulfur refining method is provided, the method adopts the above-mentioned crude sulfur refining system; the refining method comprises the following steps:

[0030] Step 1: pre-treating crude sulfur to remove water-soluble inorganic salts, water and waste gas in the crude sulfur to obtain pre-treated dry sulfur solid;

[0031] Step 2: performing a first extraction on the pretreated dry sulfur solid using a first extractant to obtain a first extract containing coal tar and a first raffinate containing sulfur;

[0032] Step 3: performing a second extraction on the first raffinate containing sulfur using a second extractant to obtain a second extract and a second raffinate containing sulfur;

[0033] Step 4: separating the first extract containing coal tar to obtain coal tar and a first recovered extracting agent;

[0034] Step 5: Separating the second sulfur-containing extract to obtain a second recovered extractant and refined sulfur.

[0035] Furthermore, the first recovered extractant in step 4 is mixed with the first extractant in step 2 to extract the pretreated dry sulfur solid.

[0036] Furthermore, the second raffinate in step 3 is subjected to solid-liquid separation to obtain a second separated liquid and a second separated solid; the second separated liquid is mixed with the first extractant in step 2 to extract the pretreated dry sulfur solid.

[0037] Furthermore, the second recovered extractant in step 5 is mixed with the second extractant in step 3 to extract the first raffinate containing sulfur.

[0038] Furthermore, in step 2, the pretreated dry sulfur solid is first crushed and then extracted.

[0039] Further, the specific process of pre-treating crude sulfur includes:

[0040] Step 1-1: washing and crushing the crude sulfur to obtain washed material;

[0041] Step 1-2: performing a first solid-liquid separation on the washed material to separate wastewater and a first sulfur-containing solid; the wastewater is treated to obtain waste salt and recycled water; the treatment temperature of the wastewater is 80° C. to 150° C.; the recycled water is used to wash the crude sulfur;

[0042] Step 1-3: Dry and dehydrate the first sulfur-containing solid to remove waste gas and moisture and obtain pre-treated dry sulfur solid, and treat the waste gas to obtain qualified gas; the drying and dehydration temperature is 80°C to 150°C.

[0043] Furthermore, the first extractant is N-methyl-2-pyrrolidone and / or benzene.

[0044] Furthermore, the second extractant is at least one of xylene, ethylene dichloride and carbon disulfide.

[0045] Furthermore, the temperature of the first extraction is 100°C to 200°C.

[0046] Furthermore, the temperature of the second extraction is 100°C to 200°C.

[0047] Furthermore, in step 4, the temperature for separating the first extract containing coal tar is 100°C to 200°C.

[0048] Furthermore, in step 5, the temperature for separating the second sulfur-containing extract is -10°C to 40°C.

[0049] By applying the technical solution of the present application, a crude sulfur refining system and method are provided, wherein the crude sulfur is pretreated to remove impurities, salt, moisture and impurities, and then the coal tar in the pretreated crude sulfur is removed by using a first extractant, and finally the sulfur in the crude sulfur is extracted by using a second extractant to obtain refined sulfur. The refined sulfur product obtained by the refining system and refining method of the present application meets the qualified product standard of industrial sulfur (GB / T 2449-2006), and can effectively reduce the harm of hazardous waste to the environment and realize the recycling of resources to the greatest extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The drawings constituting part of the present application are used to provide a further understanding of the present application. The exemplary embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0051] Figure 1 A schematic diagram of a crude sulfur refining system according to Example 1 of the present application is shown.

[0052] Figure Number:

[0053] 10. Crude sulfur pretreatment unit; 11. Water washing unit; 12. First solid-liquid separation unit; 13. Drying and dehydration unit;

[0054] 20. First extraction unit; 30. First extractant recovery unit; 40. Second extraction unit; 50. Second extractant recovery unit; 60. First extractant storage unit; 70. Second extractant storage unit; 80. Distilled water storage unit; 81. Wastewater treatment unit; 82. Waste gas treatment unit; 90. Second solid-liquid separation unit. DETAILED DESCRIPTION

[0055] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0056] Since the existing technology cannot effectively purify, recycle and utilize crude sulfur, the present application provides a crude sulfur refining system, such as Figure 1 As shown, the system includes a crude sulfur pretreatment unit 10, a first extraction unit 20, a first extractant recovery unit 30, a second extraction unit 40 and a second extractant recovery unit 50;

[0057] The crude sulfur pretreatment unit 10 has a crude sulfur inlet, a water inlet and a pretreated solid outlet; the crude sulfur pretreatment unit 10 is used to remove water-soluble inorganic salts, water and exhaust gas in the crude sulfur to form pretreated dry sulfur solids;

[0058] The first extraction unit 20 has a pre-treated solid inlet, a first extractant inlet, a first extraction phase outlet and a first raffinate phase outlet; the pre-treated solid outlet is connected to the pre-treated solid inlet; the first extraction unit 20 is used to extract a first extract containing coal tar from the pre-treated dry sulfur solid and separate a first raffinate containing sulfur;

[0059] The first extractant recovery unit 30 has a first extraction phase inlet, a first recovery extractant outlet and a coal tar outlet; the first extraction phase outlet is connected to the first extraction phase inlet; the first extractant recovery unit 30 is used to separate the first recovery extractant and coal tar from the first extract containing coal tar;

[0060] The second extraction unit 40 has a first raffinate phase inlet, a second extractant inlet, a second extract phase outlet and a second raffinate phase outlet; the first raffinate phase outlet is connected to the first raffinate phase inlet; the second extraction unit 40 is used to extract the sulfur-containing second extract from the sulfur-containing first raffinate and separate the second raffinate;

[0061] The second extractant recovery unit 50 has a second extraction phase inlet, a second recovery extractant outlet and a sulfur outlet; the second extraction phase outlet is connected to the second extraction phase inlet; the second extractant recovery unit 50 is used to separate sulfur and the second recovery extractant from the sulfur-containing second extract, and the sulfur is refined sulfur.

[0062] The structure of the crude sulfur pretreatment unit 10 of the present application can be selected from the existing technology, and its structure is not limited, as long as the water-soluble inorganic salts, water and waste gas in the crude sulfur can be removed; the structure of the above-mentioned first extraction unit 20 can be selected from the existing technology, and its structure is not limited, as long as the coal tar-containing material can be extracted from the crude sulfur; the structure of the above-mentioned first extractant recovery unit 30 can be selected from the existing technology, and its specific structure type is not limited, as long as the coal tar and the first extractant can be separated from the coal tar-containing material; the specific structure of the above-mentioned second extraction unit 40 can be selected from the existing technology, without limitation, as long as the sulfur-containing material can be extracted from the first raffinate phase; the specific structure of the above-mentioned second extractant recovery unit 50 can be selected from the existing technology, without limitation, as long as the refined sulfur can be separated from the sulfur-containing material.

[0063] The refining system designed in the present application can achieve the purpose of pre-treating crude sulfur to remove impurities, salts, moisture and impurities, then using a first extractant to remove coal tar in the pre-treated crude sulfur, and finally using a second extractant to extract sulfur from the crude sulfur to obtain refined sulfur. The system is easy to operate, has an operating time of 7,200 hours, and an annual processing capacity of 50,000 tons.

[0064] In some embodiments, the first extraction unit 20 includes an extraction tower; the second extraction unit 40 includes an extraction tower; the first extractant recovery unit 30 includes a distillation tower, more preferably a packed tower or a plate tower; the second extractant recovery unit 50 includes a cooling crystallization device.

[0065] In some embodiments, the crude sulfur pretreatment unit 10 includes a water washing unit 11, a first solid-liquid separation unit 12 and a drying and dehydration unit 13; the water washing unit 11 has a crude sulfur inlet, a water inlet and a water-washed material outlet; the water washing unit 11 is used to remove water-soluble inorganic salts in the crude sulfur to form a water-washed material; the first solid-liquid separation unit 12 has a water-washed material inlet, a wastewater outlet and a first sulfur-containing solid outlet; the water-washed material outlet is connected to the water-washed material inlet; the first solid-liquid separation unit 12 is used to separate the wastewater and the first sulfur-containing solid in the water-washed material; the drying and dehydration unit 13 has a first sulfur-containing solid inlet, a pretreatment solid outlet and a waste gas outlet; the first sulfur-containing solid outlet is connected to the first sulfur-containing solid inlet; the drying and dehydration unit 13 is used to remove moisture and waste gas in the first sulfur-containing solid to form a pretreated dry sulfur solid; preferably, the first solid-liquid separation unit 12 includes a plate and frame filter press and / or a belt filter; the drying and dehydration unit 13 includes a vacuum dryer. The present application utilizes a water-washed crude sulfur unit to dissolve soluble inorganic salts in the crude sulfur into washing water; utilizes a first solid-liquid separation unit to remove waste water; utilizes a drying and dehydration unit to further degas and dehydrate the separated solid crude sulfur to obtain dry sulfur; and the use of the above-mentioned pretreatment system can better achieve the pretreatment effect of crude sulfur to ensure that refined sulfur with higher purity is obtained.

[0066] In some embodiments, the refining system further includes a distilled water storage unit 80, a wastewater treatment unit 81 and a waste gas treatment unit 82; the outlet of the distilled water storage unit 80 is connected to the water inlet; the wastewater outlet is connected to the inlet of the wastewater treatment unit 81, the liquid outlet of the wastewater treatment unit 81 is connected to the inlet of the distilled water storage unit 80, and the solid outlet of the wastewater treatment unit 81 is used to send out the treated waste salt; the waste gas outlet is connected to the inlet of the waste gas treatment unit 82, and the waste gas treatment unit 82 is used to discharge the treated waste gas that meets the standards; preferably, the wastewater treatment unit 81 includes an evaporation crystallization device, and more preferably a multiple-effect evaporation device and / or a mechanical vapor recompression device. The present application adopts the above-mentioned structural design to better realize the recycling of water resources.

[0067] In some embodiments, the refining system further includes a first extractant storage unit 60 and a second extractant storage unit 70; the first extractant storage unit 60 has a first extractant supply inlet, a first recovery extractant inlet and a first extractant outlet; the first extractant outlet is connected to the first extractant inlet; the first recovery extractant outlet is connected to the first recovery extractant inlet; the second extractant storage unit 70 has a second extractant supply inlet, a second recovery extractant inlet and a second extractant outlet; the second extractant outlet is connected to the second extractant inlet; the second recovery extractant outlet is connected to the second recovery extractant inlet. The present application adopts the above structural design to realize the recycling of the first extractant and the second extractant, which can save resources.

[0068] In some embodiments, the refining system further comprises a second solid-liquid separation unit 90, which has a second raffinate phase inlet, a second separation liquid outlet and a second separation solid outlet; the second raffinate phase outlet is connected to the second raffinate phase inlet; the first extraction unit 20 further comprises a second separation liquid inlet; the second separation liquid outlet is connected to the second separation liquid inlet; preferably, the second solid-liquid separation unit 90 comprises a plate-frame filter press and / or a belt filter. The present application adopts the above structural design to realize the recycling of the first extractant.

[0069] According to a second aspect of the present application, a crude sulfur refining method is provided, which adopts the above-mentioned sulfur refining system; the refining method comprises the following steps:

[0070] Step 1: pre-treating crude sulfur to remove water-soluble inorganic salts, water and waste gas in the crude sulfur to obtain pre-treated dry sulfur solid;

[0071] Step 2: performing a first extraction on the pretreated dry sulfur solid using a first extractant to obtain a first extract containing coal tar and a first raffinate containing sulfur;

[0072] Step 3: performing a second extraction on the first raffinate containing sulfur using a second extractant to obtain a second extract and a second raffinate containing sulfur;

[0073] Step 4: separating the first extract containing coal tar to obtain coal tar and a first recovered extracting agent;

[0074] Step 5: Separating the second sulfur-containing extract to obtain a second recovered extractant and refined sulfur.

[0075] The coal tar separated in this application is returned to the front-end section for incineration or purification to obtain a refined sulfur product for sale.

[0076] The refining method designed in the present application combined with its system can achieve the purpose of first pre-treating crude sulfur to remove impurities, salts, moisture and impurities, then using a first extractant to remove coal tar in the pre-treated crude sulfur, and finally using a second extractant to extract sulfur from the crude sulfur to obtain refined sulfur; the obtained refined sulfur product meets the qualified product standards for industrial sulfur (GB / T2449-2006); and can effectively reduce the harm of hazardous waste to the environment and can maximize the recycling of resources.

[0077] In some embodiments, the first recovered extractant in step 4 is mixed with the first extractant in step 2 to extract the pretreated dry sulfur solid. The present application adopts this process to realize the recycling of the first extractant.

[0078] In some embodiments, the second raffinate in step 3 is subjected to solid-liquid separation to obtain a second separated liquid and a second separated solid; the second separated liquid is mixed with the first extractant in step 2 to extract the pretreated dry sulfur solid. The present application adopts this process to realize the recycling of the first extractant.

[0079] In some embodiments, the second recovered extractant in step 5 is mixed with the second extractant in step 3 to extract the first raffinate containing sulfur. The present application adopts this process to realize the recycling of the second extractant.

[0080] In some embodiments, the present application contains crushing operations in both the water washing process and the first extraction process.

[0081] In some embodiments, the specific process of pre-treating crude sulfur includes:

[0082] Step 1-1: washing crude sulfur with water to obtain a washed material;

[0083] Step 1-2: performing a first solid-liquid separation on the washed material to separate wastewater and a first sulfur-containing solid; the wastewater is treated to obtain waste salt and recycled water; the treatment temperature of the wastewater is 80° C. to 150° C.; the recycled water is used to wash the crude sulfur;

[0084] Step 1-3: Dry and dehydrate the first sulfur-containing solid to remove waste gas and moisture and obtain pre-treated dry sulfur solid, and treat the waste gas to obtain qualified gas; the drying and dehydration temperature is 80°C to 150°C.

[0085] In some embodiments, the first extractant is N-methyl-2-pyrrolidone and / or benzene; the temperature of the first extraction is 100° C. to 200° C. At this temperature, the use of the extractant can better extract coal tar from the crude sulfur-containing material without affecting the crude sulfur.

[0086] In some embodiments, the second extractant is at least one of xylene, ethylene dichloride and carbon disulfide; the temperature of the second extraction is 100° C. to 200° C. At this temperature, the use of the extractant can better extract the sulfur-containing material.

[0087] In some embodiments, the temperature for separating the first extract containing coal tar in step 4 is 100° C. to 200° C. At this temperature, the coal tar and the first extractant can be better separated.

[0088] In some embodiments, the temperature for separating the second sulfur-containing extract in step 5 is -10° C. to 40° C. At this temperature, sulfur can be better extracted and the purity can be improved.

[0089] The refined sulfur product obtained by the refining system and refining method of the present application meets the qualified product standard of industrial sulfur (GB / T 2449-2006), and can effectively reduce the harm of hazardous waste to the environment and realize the recycling of resources to the greatest extent.

[0090] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0091] The crude sulfur treated in the examples of the present application is coking desulfurized crude sulfur with a sulfur purity of 80%. The impurities are coal tar, insoluble solids, water, and soluble inorganic salts. The extractants are all commercially available.

[0092] Example 1

[0093] A system for refining crude sulfur, such as Figure 1As shown, the system includes a water washing unit 11, a first solid-liquid separation unit 12, a drying and dehydration unit 13, a first extraction unit 20, a first extractant recovery unit 30, a second extraction unit 40, a second extractant recovery unit 50, a wastewater treatment unit 81, a waste gas treatment unit 82, a distilled water storage unit 80, a first extractant storage unit 60, a second extractant storage unit 70, and a second solid-liquid separation unit 90; the input end of the water washing unit 11 can be connected to the waste sulfur and distilled water storage unit 80, and the output end of the water washing unit 11 is connected to the input end of the first solid-liquid separation unit 12; the output end of the first solid-liquid separation unit 12 includes a liquid The output end of the wastewater treatment unit 81 includes a liquid output end and a solid output end, the liquid output end is connected to the input end of the wastewater treatment unit 81, and the solid output end is connected to the input end of the drying and dehydration unit 13; the output end of the wastewater treatment unit 81 includes a liquid output end and a solid output end, the liquid output end is connected to the distilled water storage unit 80, and the solid output end is connected to the outside; the input end of the distilled water storage unit 80 includes an external supplementary water input end and a recycled water input end, the supplementary water input end is connected to the outside, and the recycled water input end is connected to the liquid output end of the wastewater treatment unit 81; the output end of the drying and dehydration unit 13 includes a gas output end and a solid output end. The gas output end is connected to the waste gas treatment unit 82, and the solid output end is connected to the first extraction unit 20; the waste gas treatment unit 82 treats the waste gas generated by the drying and dehydration unit 13 and discharges it after it meets the standards; the input end of the first extraction unit 20 includes an input end for the material to be extracted, an input end for the first extraction liquid, and an input end for the recovered liquid; the output end of the first extraction unit 20 includes an output end for the first extraction phase and a first raffinate phase; the input end for the material to be extracted is connected to the solid output end of the drying and dehydration unit 13, the first extraction liquid input end is connected to the output end of the first extractant storage unit 60, and the recovered liquid input end is connected to the solid output end of the drying and dehydration unit 13; the first extraction liquid input end is connected to the output end of the first extraction agent storage unit 60; the recovered liquid input end is connected to the solid ... drying and dehydration unit 13; the recovered liquid input end is connected to the solid output end of the first extraction agent storage unit 60; the recovered liquid input end is connected to the solid output end of the first extraction agent storage unit 60; the recovered liquid input end is connected to the solid output end of the first extraction agent storage unit 60 The first extraction phase output end is connected to the second solid-liquid separation unit 90, the first extraction phase output end is connected to the first extraction agent recovery unit 30 input end, and the first raffinate phase output end is connected to the second extraction unit 40; the output end of the first extraction agent recovery unit 30 includes a recovery extraction agent output end and an impurity output end, the recovery extraction agent output end is connected to the first extraction agent storage unit 60, and the impurity output end is connected to the outside; the input end of the first extraction agent storage unit 60 includes an outside input end and a recovery extraction agent input end, the outside input end is connected to the outside, and the recovery extraction agent input end is connected to the first extraction agent recovery unit 30;The input end of the second extraction unit 40 includes an input end for a material to be extracted and an input end for a second extracting liquid. The output end of the second extraction unit 40 includes a second extraction phase output end and a second raffinate phase output end. The input end for the material to be extracted is connected to the first raffinate phase output end of the first extraction unit 20, the second extraction liquid input end is connected to the output end of the second extractant storage unit 70, the second extraction phase output end is connected to the input end of the second extractant recovery unit 50, and the second raffinate phase output end is connected to the second solid-liquid separation unit 90. The output end of the second extractant recovery unit 50 includes a recovery The extractant output end and the product output end, the recovery extractant output end is connected to the second extractant storage unit 70, and the product output end is connected to the outside; the input end of the second extractant storage unit 70 includes an outside input end and a recovery extractant input end, the outside input end is connected to the outside, and the recovery extractant input end is connected to the second extractant recovery unit 50; the output end of the second solid-liquid separation unit 90 includes a solid insoluble matter output end and a recovery liquid output end, the solid insoluble matter output end is connected to the outside, and the recovery liquid output end is connected to the first extraction unit 20.;

[0094] Example 2

[0095] A crude sulfur refining method adopts the refining system of Example 1; the refining method comprises: external crude sulfur and washing water of a distilled water storage unit are transported into a washing unit, the crude sulfur is first crushed and then washed, and the soluble inorganic salt therein is dissolved into the washing water; the obtained solid-liquid mixture is transported into a first solid-liquid separation unit, a belt filter is used to perform a solid-liquid separation operation, the obtained liquid is transported into a wastewater treatment unit, and the obtained solid is transported into a drying and dehydration unit; the wastewater treatment unit comprises an MVR evaporation and crystallization operation, the operating temperature is 100°C, the obtained circulating water is returned to the distilled water storage unit for reuse, and the obtained miscellaneous salts are transported out as solid waste for disposal; the drying and dehydration unit is a vacuum drying and dehydration unit, the operating temperature is 100°C, the solid material is dehydrated, the obtained waste gas enters the waste gas treatment unit for treatment and is discharged after meeting the standards, and the obtained dry solid is transported into a first extraction unit;

[0096] The dried solid, the first extractant, and the recovered liquid are introduced into the first extraction unit for extraction operation, the first extractant is N-methyl-2-pyrrolidone, the extraction device is an extraction tower, the operating temperature is 120°C, the obtained first extraction phase is introduced into the first extraction agent recovery unit, and the obtained first raffinate phase is introduced into the second extraction unit; the first extraction phase is distilled in the first extraction agent recovery unit, the operating equipment is a plate tower, the operating temperature is 120°C, the obtained recovered extraction agent is introduced into the first extraction agent storage unit, and the obtained coal tar is sold to purify fine chemicals, such as thiophene, pyridine, etc.;

[0097] The first raffinate phase and the second extractant are passed into the second extraction unit for extraction operation, the second extractant is xylene, the extraction device is an extraction tower, the operating temperature is 120°C, the obtained second extract phase is passed into the second extractant recovery unit, and the obtained second raffinate phase is passed into the second solid-liquid separation unit; the second solid-liquid separation unit uses a belt filter to separate the second raffinate phase into solid and liquid, the obtained insoluble matter is transported out as solid waste for disposal, and the obtained liquid is returned to the first extraction unit; the second extract phase is subjected to a cooling and crystallization operation in the second extractant recovery unit, the operating temperature is 0°C, and refined sulfur is obtained, which meets the qualified product standard of industrial sulfur (GB / T 2449-2006), and the obtained recovered extractant is passed into the second extractant storage unit. The system and method of the present application can obtain 39,000 tons of sulfur that meets the national standard per year, the system can operate for 7,200 hours, the operation is stable, and the required crude sulfur is hazardous waste recovered from waste-producing enterprises, the raw material cost is zero, and it has great economic benefits.

[0098] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those described herein, for example.

[0099] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A crude sulfur refining system, characterized in that: The refining system comprises: A crude sulfur pretreatment unit (10) has a crude sulfur inlet, a water inlet and a pretreated solid outlet; the crude sulfur pretreatment unit (10) is used to remove water-soluble inorganic salts, water and waste gas in the crude sulfur to form pretreated dry sulfur solids; A first extraction unit (20) has a pretreated solid inlet, a first extractant inlet, a first extraction phase outlet and a first raffinate phase outlet; the pretreated solid outlet is connected to the pretreated solid inlet; the first extraction unit (20) is used to extract a first extract containing coal tar from the pretreated dry sulfur solid, and separate a first raffinate containing sulfur; A first extractant recovery unit (30) has a first extraction phase inlet, a first recovery extractant outlet and a coal tar outlet; the first extraction phase outlet is connected to the first extraction phase inlet; the first extractant recovery unit (30) is used to separate the first recovery extractant and coal tar from the first extract containing coal tar; a second extraction unit (40) having a first raffinate phase inlet, a second extractant inlet, a second extract phase outlet and a second raffinate phase outlet; the first raffinate phase outlet is connected to the first raffinate phase inlet; the second extraction unit (40) is used to extract a second extract containing sulfur from the first raffinate containing sulfur, and separate the second raffinate; The second extractant recovery unit (50) has a second extraction phase inlet, a second recovery extractant outlet and a sulfur outlet; the second extraction phase outlet is connected to the second extraction phase inlet; the second extractant recovery unit (50) is used to separate sulfur and a second recovery extractant from the sulfur-containing second extract, wherein the sulfur is refined sulfur.

2. The crude sulfur refining system according to claim 1, characterized in that: The crude sulfur pretreatment unit (10) comprises a water washing unit (11), a first solid-liquid separation unit (12) and a drying and dehydration unit (13); The water washing unit (11) has the crude sulfur inlet, the water inlet and the water-washed material outlet; the water washing unit (11) is used to remove water-soluble inorganic salts in the crude sulfur to form the water-washed material; The first solid-liquid separation unit (12) has a washed material inlet, a wastewater outlet and a first sulfur-containing solid outlet; the washed material outlet is connected to the washed material inlet; the first solid-liquid separation unit (12) is used to separate the wastewater and the first sulfur-containing solid from the washed material; The drying and dehydration unit (13) has a first sulfur-containing solid inlet, the pretreated solid outlet and a waste gas outlet; the first sulfur-containing solid outlet is connected to the first sulfur-containing solid inlet; the drying and dehydration unit (13) is used to remove moisture and waste gas from the first sulfur-containing solid to form the pretreated dry sulfur solid.

3. The crude sulfur refining system according to claim 2, characterized in that: The refining system further comprises a distilled water storage unit (80), a wastewater treatment unit (81) and a waste gas treatment unit (82); The outlet of the distilled water storage unit (80) is connected to the water inlet; the wastewater outlet is connected to the inlet of the wastewater treatment unit (81); the liquid outlet of the wastewater treatment unit (81) is connected to the inlet of the distilled water storage unit (80); and the solid outlet of the wastewater treatment unit (81) is used to send out the treated waste salt; The exhaust gas outlet is communicated with the inlet of the exhaust gas treatment unit (82), and the exhaust gas treatment unit (82) is used to discharge the exhaust gas that meets the standards after treatment.

4. The crude sulfur refining system according to any one of claims 1 to 3, characterized in that: The refining system further comprises a first extractant storage unit (60) and a second extractant storage unit (70); The first extractant storage unit (60) has a first extractant supply inlet, a first extractant recovery inlet and a first extractant outlet; the first extractant outlet is connected to the first extractant inlet; the first extractant recovery outlet is connected to the first extractant recovery inlet; The second extractant storage unit (70) has a second extractant supply inlet, a second extractant recovery inlet and a second extractant outlet; the second extractant outlet is connected to the second extractant inlet; the second extractant recovery outlet is connected to the second extractant recovery inlet.

5. The crude sulfur refining system according to any one of claims 1 to 3, characterized in that: The refining system also includes a second solid-liquid separation unit (90), which has a second raffinate phase inlet, a second separation liquid outlet and a second separation solid outlet; the second raffinate phase outlet is connected to the second raffinate phase inlet; the first extraction unit (20) also has a second separation liquid inlet; the second separation liquid outlet is connected to the second separation liquid inlet.

6. The crude sulfur refining system according to any one of claims 1 to 3, characterized in that: The first extraction unit (20) is an extraction tower; and / or the second extraction unit (40) is an extraction tower; and / or, the first extractant recovery unit (30) is a distillation tower; And / or, the second extractant recovery unit (50) is a cooling crystallization device.

7. The crude sulfur refining system according to claim 2 or 3, characterized in that: The first solid-liquid separation unit (12) comprises a plate-and-frame filter press and / or a belt filter; and / or the drying and dehydration unit (13) comprises a vacuum dryer.

8. A method for refining crude sulfur, characterized in that: The crude sulfur refining method adopts the crude sulfur refining system according to any one of claims 1 to 7; the refining method comprises the following steps: Step 1: pre-treating crude sulfur to remove water-soluble inorganic salts, water and waste gas in the crude sulfur to obtain pre-treated dry sulfur solid; Step 2: performing a first extraction on the pretreated dry sulfur solid using a first extractant to obtain a first extract containing coal tar and a first raffinate containing sulfur; Step 3: performing a second extraction on the first raffinate containing sulfur using a second extractant to obtain a second extract and a second raffinate containing sulfur; Step 4: separating the first extract containing coal tar to obtain coal tar and a first recovered extracting agent; Step 5: Separating the second sulfur-containing extract to obtain a second recovered extractant and refined sulfur.

9. The crude sulfur refining method according to claim 8, characterized in that: The first recovered extractant in step 4 is mixed with the first extractant in step 2 to extract the pretreated dry sulfur solid; and / or, the second raffinate in step 3 is subjected to solid-liquid separation to obtain a second separated liquid and a second separated solid; the second separated liquid is mixed with the first extractant in step 2 to extract the pretreated dry sulfur solid; and / or, the second recovered extractant in step 5 is mixed with the second extractant in step 3 to extract the first raffinate containing sulfur; And / or, in step 2, the pretreated dry sulfur solid is first crushed and then extracted; And / or, the specific process of pre-treating the crude sulfur comprises: Step 1-1: washing and crushing the crude sulfur to obtain a washed material; Step 1-2: performing a first solid-liquid separation on the washed material to separate wastewater and a first sulfur-containing solid; the wastewater is treated to obtain waste salt and recycled water; the treatment temperature of the wastewater is 80° C. to 150° C.; the recycled water is used to wash the crude sulfur; Step 1-3: Dry and dehydrate the first sulfur-containing solid to remove waste gas and moisture and obtain the pretreated dry sulfur solid, and the waste gas is treated to obtain qualified gas; the drying and dehydration temperature is 80°C to 150°C.

10. The crude sulfur refining method according to claim 8 or 9, characterized in that: The first extractant is N-methyl-2-pyrrolidone and / or benzene; and / or, the second extractant is at least one of xylene, ethylene dichloride and carbon disulfide; And / or, the temperature of the first extraction is 100°C to 200°C; and / or, the temperature of the second extraction is 100° C. to 200° C.; and / or, the temperature for separating the first extract containing coal tar in step 4 is 100° C. to 200° C.; And / or, the temperature for separating the sulfur-containing second extract in step 5 is -10°C to 40°C.

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