Method for removing organic matters from industrial waste salt and synchronously realizing high-value conversion

Abstract

The invention discloses a method for removing organic matters in industrial waste salt and synchronously realizing high-value conversion, and belongs to the technical field of waste salt treatment and resource reutilization. The method is based on cracking, cooling crystallization and gas recovery, and comprises the following steps: reacting industrial waste salt with a phosphorus source, removing organic matters under a high-temperature condition, synchronously carrying out high-value conversion reaction, cooling after completion to obtain sodium hexametaphosphate, recovering gas in the process, and synthesizing valuable substances. On one hand, organic pollutants in the industrial waste salt are thoroughly decomposed through high-temperature cracking, and harmlessness of the industrial waste salt is achieved; on the other hand, inorganic components in the industrial waste salt react with a phosphorus source, generated sodium hexametaphosphate can be used as a washing assistant, a mineral flotation agent and the like, gas is recycled, valuable substances are synthesized, and resource utilization of the industrial waste salt and high-value conversion of low-value waste salt are achieved. The invention provides the method for efficiently removing the organic matters in the industrial waste salt and synchronously realizing high-value conversion, and the method has a better industrial application prospect and remarkable economic and social values.

Description

Technical Field

[0001] The invention relates to the technical field of waste salt treatment and resource recycling, and in particular to a method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion. Background Art

[0002] Industrial waste salt is a solid hazardous waste containing one or more inorganic salts such as sodium chloride and sodium sulfate, which generally carries a large amount of difficult-to-degrade organic matter. Industrial waste salt comes from a wide range of sources, mainly from coal chemical industry, pesticides, printing and dyeing, fine chemicals and many other industries. Its composition is complex and the total amount is large. At present, the annual output of waste salt exceeds 20 million tons. It is difficult to handle and the cost of disposal as hazardous waste is high. Enterprises adopt the method of temporary storage or mixed utilization, which poses serious environmental risks and causes waste of resources. Therefore, industrial waste salt needs to be disposed of harmlessly and utilized as a resource.

[0003] At present, the commonly used treatment methods for waste salt are salt washing, adsorption, oxidation, heat treatment, etc. After treatment by salt washing, adsorption, oxidation and other methods, there is the problem of incomplete removal of organic pollutants. Thermal treatment includes incineration disposal, pyrolysis, etc. Thermal treatment can efficiently remove organic matter and achieve the purpose of harmless waste salt. Compared with other treatment methods, the cost of thermal treatment is higher, and the reuse value of purified sodium sulfate, sodium chloride, etc. may be lower than the treatment cost. The inorganic components in the waste salt can be treated as a raw material and mixed with certain substances to achieve the removal of organic matter from the waste salt and the simultaneous conversion into higher-value substances, so as to achieve the purpose of resource utilization and high-value conversion of waste salt. Therefore, it is necessary to develop an efficient treatment process for removing organic matter from waste salt and simultaneously converting it into high-value, so as to achieve harmless treatment, resource utilization of industrial waste salt and high-value conversion of low-value waste salt. Summary of the invention

[0004] The object of the present invention is to provide a method for removing organic matter from industrial waste salt and realizing high-value conversion simultaneously, using chloromethyl polystyrene resin or modified polystyrene resin to adsorb and remove calcium ion impurities in sodium sulfate-containing industrial waste water, and preliminarily obtaining sodium sulfate waste salt; then the sodium sulfate waste salt is reacted with ammonium dihydrogen phosphate, the organic matter is removed under high temperature conditions, and high-value conversion occurs simultaneously, and cooling is performed after the reaction is completed to obtain sodium hexametaphosphate with high yield, and gas is recovered and valuable substances are synthesized in the process, the organic matter of industrial waste salt is removed and high-value conversion is realized, and the harmlessness and resource utilization of industrial waste salt are realized.

[0005] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: A method for removing organic matter from industrial waste salt and simultaneously realizing high-value conversion comprises the following steps: firstly stirring sodium sulfate-containing industrial waste water with an adsorption resin, filtering and rotary evaporating to obtain sodium sulfate waste salt; then reacting the sodium sulfate waste salt with a phosphorus source at high temperature, quenching and crystallizing to obtain sodium hexametaphosphate, and simultaneously recovering organic waste gas generated by the reaction and converting it into valuable substances; the phosphorus source comprises at least ammonium dihydrogen phosphate and / or phosphoric acid, the organic waste gas comprises at least one of sulfur trioxide gas and ammonia, and the valuable substances comprise ammonium sulfate or sulfuric acid; the adsorption resin comprises chloromethyl polystyrene resin or modified polystyrene resin; the modified polystyrene resin has a carbonyl group and a phenol group.

[0006] The invention uses chloromethyl polystyrene resin or modified polystyrene resin to adsorb and remove calcium ion impurities in sodium sulfate-containing industrial waste water, and preliminarily obtains sodium sulfate waste salt; then the sodium sulfate waste salt is reacted with ammonium dihydrogen phosphate, organic matter is removed under high temperature conditions, and a high-value conversion reaction occurs simultaneously, and after completion, cooling is performed to obtain sodium hexametaphosphate with high yield, and gas is recovered and valuable substances are synthesized during the process, and high-value conversion is achieved while organic matter in industrial waste salt is removed, thereby achieving harmlessness and resource utilization of industrial waste salt.

[0007] Preferably, the dosage ratio of the sodium sulfate-containing industrial wastewater to the adsorption resin is 1 mL: 0.005-0.01 g.

[0008] Preferably, the mass ratio of sodium sulfate waste salt to phosphorus source is 1:1-2.

[0009] Preferably, in the high temperature reaction, the heating rate is 6-16°C / min.

[0010] Preferably, in the high temperature reaction, the reaction temperature is 500-800°C.

[0011] Preferably, in the high temperature reaction, the reaction time is 0.4-2h.

[0012] Preferably, in the quench crystallization, the cooling rate is 4-100°C / min.

[0013] Preferably, in the preparation of the modified polystyrene resin, the chloromethyl polystyrene resin is first swelled in 1,2-dichloroethane, and then reacted with 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline and 2,3,5,6-tetrafluorophenol to obtain the modified polystyrene resin. The present invention reacts the chloromethyl polystyrene resin with 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline and 2,3,5,6-tetrafluorophenol, which helps to introduce phenolic hydroxyl groups and amino groups on the chloromethyl polystyrene resin. The prepared modified polystyrene resin has good surface functionality and excellent adsorption performance, and can effectively adsorb and remove calcium ion impurities in sodium sulfate-containing industrial wastewater, thereby reducing the calcium ion content in the obtained sodium sulfate waste salt, reducing the influence of calcium ion impurities on the reaction of sodium sulfate waste salt with a phosphorus source, and effectively improving the yield of sodium hexametaphosphate generated in the reaction of sodium sulfate waste salt with a phosphorus source, thereby achieving harmlessness and resource utilization of industrial waste salt.

[0014] More preferably, the usage ratio of chloromethyl polystyrene resin and 1,2-dichloroethane is 1 g: 10-20 mL.

[0015] More preferably, the mass ratio of the chloromethyl polystyrene resin to 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline is 1:0.02-0.1.

[0016] More preferably, the mass ratio of the chloromethyl polystyrene resin to 2,3,5,6-tetrafluorophenol is 1:1-2.

[0017] Preferably, the preparation of the modified polystyrene resin comprises: Weigh chloromethyl polystyrene resin, add 1,2-dichloroethane to swell for 6-12 hours, add 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline and anhydrous ferric chloride, stir for 1-3 hours, reflux at 70-90°C for 10-15 hours, add 2,3,5,6-tetrafluorophenol and tetrahydrofuran, stir for 5-20 minutes, react at 80-90°C under nitrogen for 36-60 hours, Soxhlet extraction for 12-24 hours, and vacuum freeze-dry to obtain modified polystyrene resin.

[0018] More preferably, the usage ratio of chloromethyl polystyrene resin and 1,2-dichloroethane is 1 g: 10-20 mL.

[0019] More preferably, the mass ratio of the chloromethyl polystyrene resin to 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline is 1:0.02-0.1.

[0020] More preferably, the mass ratio of chloromethyl polystyrene resin to anhydrous ferric chloride is 1:0.1-0.5.

[0021] More preferably, the mass ratio of the chloromethyl polystyrene resin to 2,3,5,6-tetrafluorophenol is 1:1-2.

[0022] More preferably, the volume ratio of 1,2-dichloroethane to tetrahydrofuran is 1:15.

[0023] Preferably, the preparation of the modified polystyrene resin comprises: Weigh chloromethyl polystyrene resin, add 1,2-dichloroethane to swell for 6-12 hours, add 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline and anhydrous ferric chloride and stir for 1-3 hours, reflux at 70-90°C for 10-15 hours, add 2,3,5,6-tetrafluorophenol and tetrahydrofuran and stir for 5-20 minutes, react at 80-90°C and nitrogen for 36-60 hours, then add 1,4-diisocyanate butane, react at 110-130°C and nitrogen for 12-18 hours, Soxhlet extraction for 12-24 hours, vacuum freeze drying, and obtain modified polystyrene resin. The present invention further uses 1,4-diisocyanate butane to prepare modified polystyrene resin, which can further improve the surface functionality of the modified polystyrene resin and improve its adsorption performance, thereby further improving the calcium ion removal rate and the yield of sodium hexametaphosphate.

[0024] More preferably, the usage ratio of chloromethyl polystyrene resin and 1,2-dichloroethane is 1 g: 10-20 mL.

[0025] More preferably, the mass ratio of the chloromethyl polystyrene resin to 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline is 1:0.02-0.1.

[0026] More preferably, the mass ratio of chloromethyl polystyrene resin to anhydrous ferric chloride is 1:0.1-0.5.

[0027] More preferably, the mass ratio of the chloromethyl polystyrene resin to 2,3,5,6-tetrafluorophenol is 1:1-2.

[0028] More preferably, the volume ratio of 1,2-dichloroethane to tetrahydrofuran is 1:15.

[0029] More preferably, the mass ratio of the chloromethyl polystyrene resin to 1,4-diisocyanate butane is 1:0.5-1.

[0030] Preferably, a method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion is specifically, Add adsorption resin to industrial wastewater containing sodium sulfate, stir for 12-24 hours, filter and retain the supernatant, and remove the solvent by rotary evaporation to obtain sodium sulfate waste salt; mix the sodium sulfate waste salt and the phosphorus source evenly, increase the temperature to 500-800°C at a rate of 6-16°C / min, maintain for 0.4-2h, and then cool at a rate of 4-100°C / min to quench and crystallize to generate a glassy substance, which is crushed to obtain sodium hexametaphosphate.

[0031] More preferably, the phosphorus source is ammonium dihydrogen sulfate or phosphoric acid. When the phosphorus source is ammonium dihydrogen phosphate, organic waste gas and water vapor are generated during the reaction of sodium sulfate and ammonium dihydrogen phosphate, and the organic waste gas includes sulfur trioxide gas and ammonia gas. The sulfur trioxide gas and ammonia gas are recovered, and the sulfur trioxide gas, amino group and water are reacted to generate ammonium sulfate. When the phosphorus source is phosphoric acid, sulfur trioxide gas and water vapor are generated during the reaction of sodium sulfate and phosphoric acid. The sulfur trioxide gas is recovered, and the sulfur trioxide gas and water are reacted to generate ammonium sulfate.

[0032] More preferably, the adsorption resin comprises aminomethyl polystyrene resin, or modified polystyrene resin.

[0033] More preferably, the dosage ratio of the sodium sulfate-containing industrial wastewater to the adsorption resin is 1 mL: 0.005-0.01 g.

[0034] More preferably, the mass ratio of the sodium sulfate waste salt to the phosphorus source is 1:1-2.

[0035] The present invention uses chloromethyl polystyrene resin or modified polystyrene resin to absorb and remove calcium ion impurities in sodium sulfate-containing industrial wastewater to obtain sodium sulfate waste salt; and then the sodium sulfate waste salt is subjected to high-temperature reaction with a phosphorus source, so it has the following beneficial effects: the present invention uses an adsorption resin to remove calcium ion impurities in sodium sulfate-containing industrial wastewater, and the adsorption resin has a high calcium ion removal rate of 88.0-99.7%, thereby reducing the influence of calcium ion impurities on the reaction of sodium sulfate waste salt with a phosphorus source; the sodium sulfate waste salt is reacted with a phosphorus source, and the yield of the generated sodium hexametaphosphate is high, and the yield of the sodium hexametaphosphate is 75.0-98.4%. The waste salt treated by the present invention has an organic matter content lower than 15 mg / kg or meets the organic matter requirements of resource utilization, realizes the harmlessness of industrial waste salt, and effectively solves the high cost of enterprise disposal and the hidden dangers caused by the temporary storage of waste salt. The present invention can simultaneously achieve high-value conversion of low-value waste salt while removing organic matter. In the process, gas is collected and effectively converted into valuable substances, so that proliferation benefits can be obtained while processing. The process is short, the equipment is simple, and the production cost is low. The sodium hexametaphosphate produced by the technology of the present invention can be used in situ in a factory or park, effectively realizing the resource utilization of industrial waste salt and generating good economic and environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is the conversion process of Example 1 of the present invention.

[0037] Figure 2 This is the result diagram of the loss on ignition rate.

[0038] Figure 3 This is the result diagram of organic matter removal rate. DETAILED DESCRIPTION

[0039] The present invention is further described in detail below in conjunction with specific embodiments, and the examples provided are only for illustrating the present invention, rather than for limiting the scope of the present invention. The examples provided below can be used as a guide for further improvements by those of ordinary skill in the art, and do not constitute a limitation of the present invention in any way.

[0040] The experimental methods in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples are commercially available unless otherwise specified.

[0041] Embodiment 1: A method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion, comprising: Add chloromethyl polystyrene resin to the sodium sulfate-containing industrial wastewater for adsorption and stirring for 12 hours, filter and retain the supernatant, and remove the solvent by rotary evaporation to obtain sodium sulfate waste salt; mix the sodium sulfate waste salt with the phosphorus source evenly, increase the temperature to 550℃ at a rate of 10℃ / min, maintain for 1 hour, and then cool down at a rate of 16℃ / min to quench and crystallize to form a glassy substance, and then crush to obtain sodium hexametaphosphate. When the phosphorus source is ammonium dihydrogen phosphate, organic waste gas and water vapor are generated during the reaction of sodium sulfate and ammonium dihydrogen phosphate. The organic waste gas includes sulfur trioxide gas and ammonia. The sulfur trioxide gas and ammonia are recovered, and the sulfur trioxide gas, amino group and water are reacted to generate ammonium sulfate. The dosage ratio of sodium sulfate-containing industrial wastewater and chloromethyl polystyrene resin is 1mL:0.01g; the mass ratio of sodium sulfate waste salt and phosphorus source is 1:1.55.

[0042] Embodiment 2: Compared with Example 1, the difference between this example is a method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion.

[0043] A method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion, except that ammonium dihydrogen phosphate in the phosphorus source is replaced by phosphoric acid, sulfur trioxide gas and water vapor are generated during the reaction of sodium sulfate and phosphoric acid, the sulfur trioxide gas is recovered, and the sulfur trioxide gas is reacted with water to generate ammonium sulfate, and other conditions are the same as those in Example 1.

[0044] Embodiment 3: Compared with Example 1, the present embodiment differs in that a method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion is provided.

[0045] A method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion, except that the chloromethyl polystyrene resin is replaced by the modified polystyrene resin prepared in this embodiment, other conditions are the same as Example 1.

[0046] Preparation of modified polystyrene resin, comprising: Weigh chloromethyl polystyrene resin, add 1,2-dichloroethane to swell for 8 hours, add 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline and anhydrous ferric chloride and stir for 2 hours, reflux at 80°C for 12 hours, add 2,3,5,6-tetrafluorophenol and tetrahydrofuran and stir for 10 minutes, react at 85°C and nitrogen for 48 hours, Soxhlet extraction for 12 hours, vacuum freeze-drying, and obtain modified polystyrene resin. The dosage ratio of chloromethyl polystyrene resin and 1,2-dichloroethane is 1g:10mL; the mass ratio of chloromethyl polystyrene resin and 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline is 1:0.1; the mass ratio of chloromethyl polystyrene resin and anhydrous ferric chloride is 1:0.25; the mass ratio of chloromethyl polystyrene resin and 2,3,5,6-tetrafluorophenol is 1:1.2; the volume ratio of 1,2-dichloroethane and tetrahydrofuran is 1:15.

[0047] Embodiment 4: Compared with Example 3, the present embodiment differs in that a method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion is provided.

[0048] A method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion, except that the dosage ratio of sodium sulfate-containing industrial wastewater and modified polystyrene resin is changed to 1 mL: 0.005 g, other conditions are the same as Example 2.

[0049] Embodiment 5: Compared with Example 1, the present embodiment differs in that a method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion is provided.

[0050] A method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion, except that the chloromethyl polystyrene resin is replaced by the modified polystyrene resin prepared in this embodiment, other conditions are the same as Example 1.

[0051] Preparation of modified polystyrene resin, comprising: Weigh chloromethyl polystyrene resin, add 1,2-dichloroethane to swell for 8 hours, add 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline and anhydrous ferric chloride, stir for 2 hours, reflux at 80°C for 12 hours, add 2,3,5,6-tetrafluorophenol and tetrahydrofuran, stir for 10 minutes, react at 85°C under nitrogen for 48 hours, then add 1,4-diisocyanate butane, react at 120°C under nitrogen for 14 hours, Soxhlet extraction for 12 hours, and vacuum freeze-dry to obtain modified polystyrene resin. The dosage ratio of chloromethyl polystyrene resin and 1,2-dichloroethane is 1g:10mL; the mass ratio of chloromethyl polystyrene resin and 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline is 1:0.1; the mass ratio of chloromethyl polystyrene resin and anhydrous ferric chloride is 1:0.25; the mass ratio of chloromethyl polystyrene resin and 2,3,5,6-tetrafluorophenol is 1:1.2; the volume ratio of 1,2-dichloroethane and tetrahydrofuran is 1:15; the mass ratio of chloromethyl polystyrene resin and 1,4-diisocyanate butane is 1:0.7.

[0052] Embodiment 6: Compared with Example 5, the present embodiment differs in that a method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion is provided.

[0053] A method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion, except that the dosage ratio of sodium sulfate-containing industrial wastewater and modified polystyrene resin is changed to 1 mL: 0.005 g, other conditions are the same as Example 4.

[0054] Comparative Example 1: The difference between this comparative example and Example 3 lies in the preparation of the modified polystyrene resin.

[0055] The preparation of the modified polystyrene resin was carried out under the same conditions as in Example 3 except that 2,3,5,6-tetrafluorophenol was not added.

[0056] Comparative Example 2: The difference between this comparative example and Example 3 lies in the preparation of the modified polystyrene resin.

[0057] The preparation of the modified polystyrene resin was carried out under the same conditions as in Example 3 except that 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline was not added.

[0058] Comparative Example 3: The difference between this comparative example and Example 5 lies in the preparation of the modified polystyrene resin.

[0059] The preparation of the modified polystyrene resin was carried out under the same conditions as in Example 5 except that 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline and 2,3,5,6-tetrafluorophenol were not added.

[0060] Experimental example: 1. Inactive phosphate content According to the method of Example 1-2, the sodium sulfate-containing industrial wastewater is converted into sodium hexametaphosphate. According to the industrial sodium hexametaphosphate industry standard HG / T 2519-2017, the inactive phosphate content in the sodium hexametaphosphate obtained by the conversion in Example 1-2 is analyzed.

[0061] Figure 1 The conversion process of Example 1 of the present invention is as follows: first, sodium sulfate-containing industrial wastewater is mixed with an adsorption resin to adsorb organic matter, and sodium sulfate waste salt is obtained after the solvent is removed by rotary evaporation; then, the sodium sulfate waste salt is mixed with a phosphorus source and put into a cracking furnace, and double decomposition reaction, dehydration, and polymerization reaction are carried out under high temperature conditions. After the reaction is completed, sodium hexametaphosphate is obtained by quenching, cooling, crystallization, grinding, and crushing. During the reaction, gas is recovered and valuable substances are synthesized. The inactive phosphate content in the sodium hexametaphosphate generated in Example 1 of the present invention is 4%, which is lower than the limit range of the industry standard HG / T 2519-2017; the inactive phosphate content in the sodium hexametaphosphate generated in Example 2 of the present invention is 6%, which is lower than the limit range of the industry standard HG / T 2519-2017. This shows that the inactive phosphate content in the sodium hexametaphosphate obtained by the methods of Examples 1 and 2 of the present invention is within the specified range of the industry standard HG / T2519-2017, and it can be used as a washing aid, a water softener for industrial water, a detergent, a corrosion inhibitor, a flotation agent, a dispersant, a rust remover, a cement hardener, etc. It can also be used as a scale inhibitor in electrodialysis, reverse osmosis, nanofiltration and other membrane treatment processes in the near-zero discharge process of industrial wastewater.

[0062] 2. Loss on ignition rate According to the method of Example 1-2, organic matter in sodium sulfate-containing industrial wastewater is removed to extract sodium sulfate waste salt; and then the sodium sulfate waste salt is reacted with a phosphorus source to generate a solid product. A control group is set up, in which, except that the sodium sulfate waste salt is replaced with pure sodium sulfate product, other conditions are the same as Example 1.

[0063] Before the reaction of sodium sulfate waste salt or pure sodium sulfate product with the phosphorus source, the total mass of sodium sulfate waste salt or pure sodium sulfate product and phosphorus source is measured, recorded as G1; after the reaction of sodium sulfate waste salt or pure sodium sulfate product with the phosphorus source, the total mass of the solid product generated by the reaction is measured, recorded as G2. Calculate the loss on ignition of the control group, Example 1 and Example 2. Loss on ignition (%) = (G1-G2) / G1×100%.

[0064] Figure 2 The results of the burning rate are shown in Figure 1, where S1 is the burning rate of the control group, S2 is the burning rate of Example 1, and S3 is the burning rate of Example 2. This shows that the process conditions of the present invention can make the sodium sulfate waste salt react completely with the phosphorus source.

[0065] 3. Organic matter removal rate The sodium sulfate waste salt of Example 1 was collected, and the total organic carbon content in the solid product generated by the reaction at different high temperature temperatures was determined using a total organic carbon analyzer, which was recorded as X1. A control group and an experimental group were set up. In the control group, the sodium sulfate waste salt was roasted under high temperature conditions for 1 hour, and then quenched and crystallized to obtain a solid product. In the experimental group, the sodium sulfate waste salt and ammonium dihydrogen phosphate were roasted under high temperature conditions for 1 hour, and then quenched and crystallized to obtain a solid product. The high temperature temperatures were 300°C, 400°C, 500°C and 600°C, respectively. A total organic carbon analyzer was used to determine the total organic carbon content in the solid product generated by the reaction at different high temperature temperatures, which was recorded as X2. Organic matter removal rate (%) = (X1-X2) / X1×100%.

[0066] Figure 3 The result diagram of organic matter removal rate is shown in Figure 1, where S1 is the organic matter removal rate of the control group and S2 is the organic matter removal rate of the experimental group. Under the condition of 300°C, the organic matter removal rate of the control group is 56%, and the organic matter removal rate of the experimental group is 88%. This shows that the present invention uses sodium sulfate waste salt and diammonium phosphate to react at high temperature, which can promote the decomposition of organic matter.

[0067] 4. Calcium ion removal rate Collect industrial wastewater containing sodium sulfate, and determine the calcium ion content in the industrial wastewater containing sodium sulfate by EDTA titration, which is recorded as X1. Use adsorption resin to treat industrial wastewater containing sodium sulfate according to the methods of Examples 1-6 and Comparative Examples 1-3, respectively, to obtain sodium sulfate waste salt, and determine the residual calcium ion content in the sodium sulfate waste salt by EDTA titration, which is recorded as X2. Calculate the calcium ion removal rate (%) = (X1-X2) / X2×100%, and the results of the determination of calcium ion removal efficiency are shown in Table 1.

[0068] Table 1 Calcium ion removal rate

[0069] It can be seen from Table 1 that the calcium ion removal rate of Example 3-4 of the present invention is higher than that of Example 1-2, because Example 3-4 uses 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline and 2,3,5,6-tetrafluorophenol to prepare modified polystyrene resin, and the modified polystyrene resin is used to treat sodium sulfate-containing industrial wastewater, while Example 1-2 uses chloromethyl polystyrene resin; the calcium ion removal rate of Example 3-4 of the present invention is higher than that of Comparative Example 1-2, because Comparative Example 1 only uses 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline to prepare modified polystyrene resin, and Comparative Example 2 only uses 2,3,5,6-tetrafluorophenol to prepare modified polystyrene resin; the calcium ion removal rate of Example 3 of the present invention is higher than that of Example 4, because the amount of modified polystyrene resin used is different. This shows that the synergistic use of 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline and 2,3,5,6-tetrafluorophenol to prepare modified polystyrene resin can improve the removal rate of modified polystyrene resin for calcium ions in sodium sulfate-containing industrial wastewater.

[0070] The calcium ion removal rate of Examples 5-6 of the present invention is higher than that of Example 3 because Examples 5-6 further use 1,4-diisocyanate butane to prepare the modified polystyrene resin; the calcium ion removal rate of Examples 5-6 is higher than that of Comparative Example 3 because Comparative Example 3 only uses 1,4-diisocyanate butane to prepare the modified polystyrene resin, but does not use 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline and 2,3,5,6-tetrafluorophenol; the calcium ion removal rate of Example 5 of the present invention is higher than that of Example 6 because the amount of modified polystyrene resin used is different. This shows that further using 1,4-diisocyanate butane to prepare the modified polystyrene resin can further improve the removal rate of calcium ions in sodium sulfate-containing industrial wastewater by the modified polystyrene resin.

[0071] 4. Yield of Sodium Hexametaphosphate According to the methods of Examples 1-6 and Comparative Examples 1-3, the sodium sulfate-containing industrial wastewater was converted into sodium hexametaphosphate. According to the industrial sodium hexametaphosphate industry standard HG / T 2519-2017, the sodium hexametaphosphate yields obtained in Examples 1-6 and Comparative Examples 1-3 were analyzed, and the sodium hexametaphosphate yield was calculated. Yield (%) = actual sodium hexametaphosphate yield / theoretical sodium hexametaphosphate yield × 100%, and the measurement results are shown in Table 2.

[0072] Table 2 Sodium hexametaphosphate yield (%)

[0073] As can be seen from Table 2, the yield of sodium hexametaphosphate in Example 3-4 of the present invention is higher than that in Example 1-2, because Example 3-4 uses 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline and 2,3,5,6-tetrafluorophenol to prepare modified polystyrene resin, and the modified polystyrene resin is used to adsorb and remove calcium ion impurities in sodium sulfate-containing industrial wastewater to preliminarily obtain sodium sulfate waste salt, and then the sodium sulfate waste salt is reacted with a phosphorus source to convert it into sodium hexametaphosphate, thereby improving the yield of sodium hexametaphosphate, while Example 1-2 uses chloromethyl polystyrene resin; the yield of sodium hexametaphosphate in Example 3-4 of the present invention is higher than that in Comparative Example 1-2, because Comparative Example 1 only uses 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline to prepare modified polystyrene resin, and Comparative Example 2 only uses 2,3,5,6-tetrafluorophenol to prepare modified polystyrene resin; the yield of sodium hexametaphosphate in Example 3 of the present invention is higher than that in Example 4, because the amount of modified polystyrene resin used is different. This shows that the synergistic use of 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline and 2,3,5,6-tetrafluorophenol to prepare modified polystyrene resin, and the use of modified polystyrene resin to remove calcium ion impurities in sodium sulfate-containing industrial wastewater, initially obtaining sodium sulfate waste salt, and then reacting the sodium sulfate waste salt with a phosphorus source to convert it into sodium hexametaphosphate can effectively increase the yield of sodium hexametaphosphate.

[0074] The yield of sodium hexametaphosphate in Example 5-6 of the present invention is higher than that in Example 3 because 1,4-diisocyanate butane is further used in Example 5-6 to prepare the modified polystyrene resin; the yield of sodium hexametaphosphate in Example 5-6 is higher than that in Comparative Example 3 because Comparative Example 3 only uses 1,4-diisocyanate butane to prepare the modified polystyrene resin, but does not use 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline and 2,3,5,6-tetrafluorophenol; the yield of sodium hexametaphosphate in Example 5 of the present invention is higher than that in Example 6 because the amount of modified polystyrene resin used is different. This shows that further using 1,4-diisocyanate butane to prepare the modified polystyrene resin, and using the modified polystyrene resin to remove calcium ion impurities in sodium sulfate-containing industrial wastewater, initially obtaining sodium sulfate waste salt, and then reacting the sodium sulfate waste salt with a phosphorus source to convert it into sodium hexametaphosphate can further improve the yield of sodium hexametaphosphate.

[0075] The conventional operations in the operating steps of the present invention are well known to those skilled in the art and will not be described in detail here.

[0076] The embodiments described above provide a detailed description of the technical solutions of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, supplements or similar substitutions made within the scope of the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion, comprising: first stirring sodium sulfate-containing industrial waste water with an adsorption resin, filtering, and rotary evaporating to obtain sodium sulfate waste salt; then reacting the sodium sulfate waste salt with a phosphorus source at high temperature, quenching and crystallizing to obtain sodium hexametaphosphate, and simultaneously recovering the organic waste gas generated by the reaction and converting it into valuable substances; the phosphorus source at least includes ammonium dihydrogen phosphate and / or phosphoric acid, the organic waste gas includes at least one of sulfur trioxide gas and ammonia, and the valuable substance includes ammonium sulfate or sulfuric acid; the adsorption resin includes chloromethyl polystyrene resin or modified polystyrene resin; the modified polystyrene resin has a carbonyl group and a phenol group.

2. According to the method for removing organic matter from industrial waste salt and realizing high-value conversion simultaneously as described in claim 1, it is characterized in that: The dosage ratio of the sodium sulfate-containing industrial wastewater to the adsorption resin is 1 mL: 0.005-0.01 g.

3. According to the method for removing organic matter from industrial waste salt and realizing high-value conversion simultaneously as described in claim 1, it is characterized in that: The mass ratio of the sodium sulfate waste salt to the phosphorus source is 1:1-2.

4. According to the method for removing organic matter from industrial waste salt and realizing high-value conversion simultaneously as described in claim 1, it is characterized in that: In the high temperature reaction, the heating rate is 6-16°C / min.

5. According to the method for removing organic matter from industrial waste salt and realizing high-value conversion simultaneously as described in claim 1, it is characterized in that: In the high temperature reaction, the reaction temperature is 500-800°C.

6. A method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion according to claim 1, characterized in that: In the high temperature reaction, the reaction time is 0.4-2h.

7. A method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion according to claim 1, characterized in that: In the quenching crystallization, the cooling rate is 4-100°C / min.

8. A method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion according to claim 1, characterized in that: In the preparation of the modified polystyrene resin, the chloromethyl polystyrene resin is first swelled in 1,2-dichloroethane, and then reacted with 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline and 2,3,5,6-tetrafluorophenol to obtain the modified polystyrene resin.

9. A method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion according to claim 7, characterized in that: The usage ratio of the chloromethyl polystyrene resin and 1,2-dichloroethane is 1g:10-20mL.

10. A method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion according to claim 7, characterized in that: The mass ratio of the chloromethyl polystyrene resin to 2-methyl-3-(1-pyrrolidinylcarbonyl)aniline is 1:0.02-0.

1.

11. A method for removing organic matter from industrial waste salt and simultaneously achieving high-value conversion according to claim 7, characterized in that: The mass ratio of the chloromethyl polystyrene resin to 2,3,5,6-tetrafluorophenol is 1:1-2.

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