A biomass phosphogypsum recycled material, its solid waste collaborative recycling process and application

Abstract

This application relates to the technical field of phosphogypsum solid waste treatment, and specifically discloses a biomass phosphogypsum recycled material, its solid waste collaborative recycling process and application. A biomass phosphogypsum recycled material is mainly made of the following raw materials in parts by weight: 80-120 parts of phosphogypsum, 35-50 parts of biomass solid waste, 5-7 parts of construction waste soil, 2-5 parts of sludge, 1-3 parts of quicklime, 2-3.5 parts of accelerator, and 5.5-8 parts of adsorbent; the accelerator is composed of zinc chloride and ammonium chloride in a molar ratio of (2-3):(0.5-1); the adsorbent is composed of a base material, chitosan quaternary ammonium salt, and hydroxyoxide in a mass ratio of (10-18):(7-15):(3-8). The biomass phosphogypsum recycled material of this application can be used in industries such as soil improvement treatment, agricultural production, and construction. It has the advantages of difficult release of heavy metal components, safety and environmental protection.

Description

Technical Field

[0001] This application relates to the technical field of phosphogypsum solid waste treatment. More specifically, it relates to a biomass phosphogypsum recycled material, its solid waste collaborative recycling process, and applications. Background Art

[0002] Phosphogypsum is an industrial by-product discharged during the production of wet-process phosphoric acid. Although there are many ways to utilize phosphogypsum, the resource utilization rate is very low. Currently, it is mainly treated by stacking, which not only occupies a large area but also produces harmful components such as free acid, organic matter, and heavy metals during long-term stacking, endangering the soil and groundwater.

[0003] Agricultural solid waste is a large amount of waste generated in agricultural production, which can be mainly divided into crop appendages (such as straw), agricultural processing waste (such as fruit pulp, distillers' grains, etc.), and breeding waste (such as animal manure). Most of these agricultural solid wastes are not rationally treated and are randomly discharged, resulting in environmental deterioration.

[0004] How to comprehensively utilize phosphogypsum and agricultural solid waste has always been a technical problem that technicians want to solve. For example, the Chinese patent application document with the publication number CN108929695A discloses an organic matter-containing phosphogypsum soil conditioner and its preparation method. The organic matter is mixed with phosphogypsum, and then components such as water retention, root growth promotion, sterilization, and promoters are added to make a granular soil conditioner, which can comprehensively utilize the two.

[0005] Another example is the Chinese patent application document with the publication number CN105272715A, which discloses a phosphogypsum soil conditioner composed of the following raw materials in parts by weight: 720 - 760 of phosphogypsum, 50 - 60 of amino acid chelate, 100 - 120 of plant ash, 50 - 60 of amino acid, 45 - 50 of ferrous sulfate, 3 - 5 of boric acid, and 0.6 - 1 of functional biological bacteria. Using the existing wasted phosphogypsum resources, it effectively solves the problem of soil salinization and can effectively balance, improve, and condition the soil components.

[0006] For the above-mentioned comprehensive utilization processes of phosphogypsum and agricultural solid waste, although some harmless components in phosphogypsum are utilized, harmful substances such as heavy metals and fluoride ions in phosphogypsum will gradually be released over time, causing greater harm, reducing the comprehensive utilization rate and application range. Summary of the Invention

[0007] In order to reduce the release amount of heavy metal components in phosphogypsum and improve the comprehensive utilization rate of phosphogypsum and agricultural solid waste, this application provides a biomass phosphogypsum recycled material, its solid waste collaborative recycling process, and applications.

[0008] In a first aspect, the present application provides a biomass phosphogypsum recycled material, adopting the following technical solution:

[0009] A biomass phosphogypsum recycled material is mainly made of the following raw materials in parts by weight: 80 - 120 parts of phosphogypsum, 35 - 50 parts of biomass solid waste, 5 - 7 parts of construction waste soil, 2 - 5 parts of sludge, 1 - 3 parts of quicklime, 2 - 3.5 parts of promoter, and 5.5 - 8 parts of adsorbent; the promoter is composed of zinc chloride and ammonium chloride in a molar ratio of (2 - 3):(0.5 - 1); the adsorbent is composed of a base material, chitosan quaternary ammonium salt, and hydroxyoxide in a mass ratio of (10 - 18):(7 - 15):(3 - 8).

[0010] By adopting the above technical solution, the phosphogypsum and biomass solid waste are pretreated and then sent into a high-temperature kiln for anoxic calcination and regeneration treatment. In a high-temperature and anoxic environment, a part of the biomass solid waste will burn to produce plant ash, and the alkaline plant ash will react with the acidic harmful substances in the phosphogypsum to neutralize the reaction and reduce the harmfulness of the phosphogypsum.

[0011] Another part of the biomass solid waste will form biochar under the activation of the promoter, and the unneutralized acidic substances in the phosphogypsum and the water vapor generated under high-temperature action will also have complex physical and chemical effects on the formed biochar, further promoting the formation of a finer mesoporous structure on the surface of the biochar and increasing the specific surface area of the biochar.

[0012] At the same time, harmful substances such as heavy metals in the phosphogypsum will gradually be released in a high-temperature environment, and complexation adsorption will occur between the chitosan quaternary ammonium salt and hydroxyoxide in the adsorbent to form adsorbents. The sizes of these adsorbents are very small, and they will adsorb on the surface of the biochar formed by the biomass solid waste and gradually migrate into the interior of the biochar particles, which can inhibit the reverse migration of heavy metal components, thereby reducing the release rate of heavy metal components.

[0013] Moreover, as the calcination time continues to pass, the base material in the adsorbent will block and wrap the surface of the biochar particles and gradually solidify to form a coating under high-temperature conditions. A part of the surface of these coating structures will undergo partial melting and crystallization during the calcination process, further hindering the reverse release of harmful heavy metal components inside, and finally obtaining a safe phosphogypsum and biomass recycled material that is not easy to release heavy metals, greatly reducing the heavy metal release rate during the use of the recycled phosphogypsum and biomass solid waste, and enabling full resource utilization.

[0014] Preferably, the hydroxyoxide is at least one of iron oxyhydroxide, nickel oxyhydroxide, aluminum oxyhydroxide, and manganese oxyhydroxide.

[0015] By adopting the above technical solutions, the types of hydroxyoxides are optimized and adjusted, the adsorption effect and adsorption efficiency of hydroxyoxides on heavy metal ions are balanced, the adsorption competition with biochar is reduced, so that the heavy metal components first undergo molecular binding with chitosan quaternary ammonium salt and hydroxyoxides, and then undergo adsorption binding with biochar, enhancing the shielding effect on heavy metal elements.

[0016] Preferably, the hydroxyoxide is composed of iron hydroxyoxide and aluminum hydroxyoxide in a molar ratio of (20 - 26):(6 - 9.5).

[0017] By adopting the above technical solutions, the composition ratio of hydroxyoxides is further tested, the ineffective adsorption rate of heavy metal components is reduced, and the inhibitory effect on the back-migration of heavy metal components is improved.

[0018] Preferably, the base material is at least one of clay, bentonite, and fly ash.

[0019] By adopting the above technical solutions, the type composition of the base material is optimized and adjusted, the plugging and coating effects on the mesoporous structure of the adsorbent surface are enhanced, and crystalline substances are formed within the pore structure of biochar, further reducing the release amount of heavy metal elements during the use of recycled materials.

[0020] Preferably, the mass ratio of the adsorbent to the promoter is (2.34 - 2.75):1.

[0021] By adopting the above technical solutions, the ratio of the adsorbent to the promoter is optimized and adjusted, the proportion of the adsorbent and the coating body is balanced, so that the adsorption and coating processes proceed orderly and smoothly, reducing the occurrence probability of ineffective adsorption phenomena such as semi-adsorbents or semi-coated bodies.

[0022] Preferably, the raw materials further include 1.5 - 2.2 parts by weight of molybdenum disulfide.

[0023] By adopting the above technical solutions, after adding molybdenum disulfide, the activation structure of biochar can be further improved, and the solidification ability of biochar to the adsorbent can be enhanced.

[0024] In a second aspect, the present application provides a solid waste co-regeneration process for biomass phosphogypsum recycled materials, adopting the following technical solutions:

[0025] A solid waste co-regeneration process for biomass phosphogypsum recycled materials includes the following steps:

[0026] S1: Sort the biomass solid waste to remove sundries such as metals and plastics for later use;

[0027] S2: Crush and screen the phosphogypsum for later use;

[0028] S3: Weigh the biomass solid waste, phosphogypsum, construction waste soil, sludge, quicklime, promoter, and adsorbent in accordance with the formula amount, mix them evenly, add them into a high-temperature kiln, and conduct anoxic high-temperature calcination, regeneration, and cooling.

[0029] By adopting the above technical solution, the biomass solid waste and phosphogypsum are put into a high-temperature kiln for calcination, giving full play to their respective roles. While weakening the toxicity of phosphogypsum, the heavy metal components are adsorbed and sealed, which can effectively inhibit the reverse release of heavy metal components and obtain a safer and more environmentally friendly solid waste regenerated material.

[0030] Preferably, the high-temperature calcination includes primary calcination and secondary calcination. The primary calcination temperature is 280 - 320 °C, and the calcination time is 2 - 3.5 h; the secondary calcination temperature is 350 - 460 °C, and the calcination time is 25 - 35 min.

[0031] By adopting the above technical solution, treating the solid waste at a relatively low calcination temperature first can promote the formation of biochar. Then, treating it at a higher calcination temperature can cause the heavy metal components in phosphogypsum to be fully released, while also promoting the activation of biochar. Moreover, it provides suitable temperature conditions for the complexation of the adsorbent and heavy metal components, the adsorption of the adsorbent by biochar, and the formation of the coating body.

[0032] Preferably, the step S3 also includes the step of adding molybdenum disulfide.

[0033] In the third aspect, the present application provides an application of the biomass phosphogypsum regenerated material, which can be used for soil improvement, agricultural production, sewage treatment, and construction.

[0034] In summary, the present application has the following beneficial effects:

[0035] 1. Since the present application uses biomass solid waste and phosphogypsum for collaborative regeneration treatment in a high-temperature kiln, the heavy metal components are complexed and chelated by the adsorbent, and the biochar produced from the biomass solid waste is used to seal the formed adsorbent body. Under the combined action of the adsorbent, promoter, and biochar, the reverse release rate of heavy metal components during the use of the regenerated material is greatly reduced, which is more environmentally friendly.

[0036] 2. In the present application, the types and ratios of hydroxyoxides and base materials are optimized and adjusted, and other process regulations are optimized at the same time to further inhibit the release of heavy metal components in the regenerated material.

[0037] 3. The biomass phosphogypsum regenerated material prepared by the solid waste collaborative regeneration process of the present application has a very low heavy metal release amount and is very suitable for popularization and use in fields such as soil regulation, sewage treatment, and agricultural production. Specific embodiments

[0038] The following further elaborates on this application in conjunction with embodiments.

[0039] The raw materials in the embodiments and comparative examples of this application are all ordinary commercially available, unless otherwise specified.

[0040] Embodiment

[0041] Embodiment 1

[0042] The biomass phosphogypsum recycled material of this embodiment is made from the following raw materials by weight: 120 kg of phosphogypsum, 35 kg of biomass solid waste, 5 kg of construction waste soil, 5 kg of sludge, 1 kg of quicklime, 2 kg of promoter, and 5.5 kg of adsorbent.

[0043] Among them, the biomass solid waste is agricultural straw. The sludge is urban and rural sludge. The promoter is composed of zinc chloride and ammonium chloride in a molar ratio of 2:1.

[0044] The adsorbent is composed of a base material, chitosan quaternary ammonium salt, and hydroxyoxide in a mass ratio of 10:7:8. The hydroxyoxide is iron hydroxyoxide. The base material is composed of bentonite and fly ash in a mass ratio of 1:3.

[0045] The solid waste co-recycling process of the biomass phosphogypsum recycled material of this embodiment includes the following steps:

[0046] S1: Sort the biomass solid waste to remove most of the metal, plastic, soil and stone and other impurities, then remove small particle metal impurities through magnetic separation, and then dry, pulverize and store in the warehouse for later use;

[0047] S2: Put the phosphogypsum into a dryer for drying treatment, then crush and screen it, and send it into a pulverizer for pulverization. The pulverized phosphogypsum is stored in the warehouse for later use;

[0048] S3: Take the biomass solid waste, phosphogypsum, construction waste soil, sludge, quicklime, promoter, and adsorbent in the amount of the formula in step S1, mix them evenly, add them to a high-temperature kiln, and carry out anoxic high-temperature calcination and regeneration at a temperature of 300 °C for 3 hours. Then cool, discharge, and pulverize to obtain the biomass phosphogypsum recycled material.

[0049] The application of the biomass phosphogypsum recycled material of this embodiment can be used in soil improvers, agricultural cultivation soil, pond bottom soil, urban and rural sewage treatment, and construction.

[0050] Embodiment 2

[0051] The biomass phosphogypsum recycled material of this embodiment is made from the following raw materials by weight: 80 kg of phosphogypsum, 50 kg of biomass solid waste, 7 kg of construction waste soil, 2 kg of sludge, 3 kg of quicklime, 3.5 kg of promoter, and 8 kg of adsorbent.

[0052] Among them, the biomass solid waste is soybean residue. The sludge is urban and rural sludge. The promoter is composed of zinc chloride and ammonium chloride in a molar ratio of 3:0.5.

[0053] The adsorbent is composed of a base material, chitosan quaternary ammonium salt, and hydroxy oxide in a mass ratio of 10:7:8. The hydroxy oxide is iron hydroxy oxide. The base material is fly ash.

[0054] The solid waste co-regeneration process of the biomass phosphogypsum regenerated material in this embodiment includes the following steps:

[0055] S1: Sort the biomass solid waste to remove most of the sundries such as metals, plastics, soil and stones, then remove small particle metal sundries through magnetic separation, and then air dry, dry, crush and store in the warehouse for later use;

[0056] S2: Put the phosphogypsum into a dryer for drying treatment, then send it to a crusher and sieve, and then send it into a powder mill for grinding. The ground phosphogypsum is stored in the warehouse for later use;

[0057] S3: Take the biomass solid waste, phosphogypsum, construction waste soil, sludge, quicklime, promoter, and adsorbent in the amounts according to the formula, mix them evenly, add them to a high-temperature kiln, and carry out anoxic high-temperature calcination and regeneration at a temperature of 350 °C for 2.5 h. Then cool, discharge, and grind to obtain the biomass phosphogypsum regenerated material.

[0058] The application of the biomass phosphogypsum regenerated material in this embodiment can be used in soil conditioners, agricultural cultivation soil, pond bottom soil, urban and rural sewage treatment, and construction.

[0059] Example 3

[0060] The biomass phosphogypsum regenerated material in this embodiment is made from the following raw materials by weight: 115 kg of phosphogypsum, 46 kg of biomass solid waste, 5.5 kg of construction waste soil, 3 kg of sludge, 2.5 kg of quicklime, 3.2 kg of promoter, and 7.5 kg of adsorbent.

[0061] Among them, the biomass solid waste is distiller's grains. The sludge is urban and rural sludge. The promoter is composed of zinc chloride and ammonium chloride in a molar ratio of 2.5:0.6.

[0062] The adsorbent is composed of a base material, chitosan quaternary ammonium salt, and hydroxy oxide in a mass ratio of 10:7:8. The hydroxy oxide is iron hydroxy oxide. The base material is composed of clay and fly ash in a mass ratio of 6:1.5.

[0063] The solid waste co-regeneration process of the biomass phosphogypsum regenerated material in this embodiment includes the following steps:

[0064] S1: Sort and remove most of the impurities such as metals, plastics, soil and stones from the biomass solid waste. Then remove small particle metal impurities through magnetic separation. Next, air dry, dry and crush it, and store it in the warehouse for later use;

[0065] S2: Put the phosphogypsum into a dryer for drying treatment. Then, after crushing and screening, send it into a pulverizer for grinding. The ground phosphogypsum is stored in the warehouse for later use;

[0066] S3: Weigh the biomass solid waste, phosphogypsum, construction waste soil, sludge, quicklime, accelerator and adsorbent in accordance with the recipe amounts, mix them evenly, add them to a high-temperature kiln, and conduct anoxic high-temperature calcination and regeneration at a temperature of 350 °C for 2.5 hours. Then, cool, discharge and grind them to obtain the biomass phosphogypsum recycled material.

[0067] The application of the biomass phosphogypsum recycled material in this example can be used in soil conditioners, agricultural cultivation soil, pond bottom soil, urban and rural sewage treatment, and construction.

[0068] Example 4

[0069] The difference between the biomass phosphogypsum recycled material in this example and that in Example 3 lies in that the adsorbent in the raw materials is composed of a base material, chitosan quaternary ammonium salt and hydroxyoxide in a mass ratio of 18:15:3, and the rest is the same as that in Example 3.

[0070] The solid waste co-regeneration process of the biomass phosphogypsum recycled material in this example is the same as that in Example 3.

[0071] The application of the biomass phosphogypsum recycled material in this example is the same as that in Example 3.

[0072] Example 5

[0073] The difference between the biomass phosphogypsum recycled material in this example and that in Example 3 lies in that the adsorbent in the raw materials is composed of a base material, chitosan quaternary ammonium salt and hydroxyoxide in a mass ratio of 15:12:5.5, and the rest is the same as that in Example 3.

[0074] The solid waste co-regeneration process of the biomass phosphogypsum recycled material in this example is the same as that in Example 3.

[0075] The application of the biomass phosphogypsum recycled material in this example is the same as that in Example 3.

[0076] Example 6

[0077] The difference between the biomass phosphogypsum recycled material in this example and that in Example 5 lies in that the hydroxyoxide in the raw materials is composed of nickel hydroxyoxide and manganese hydroxyoxide in a mass ratio of 5:3, and the rest is the same as that in Example 5.

[0078] The solid waste co-regeneration process of the biomass phosphogypsum recycled material in this embodiment is the same as that in Example 5.

[0079] The application of the biomass phosphogypsum recycled material in this embodiment is the same as that in Example 5.

[0080] Example 7

[0081] The difference between the biomass phosphogypsum recycled material in this embodiment and that in Example 5 is that: the hydroxyoxides in the raw materials are composed of iron hydroxyoxide and aluminum hydroxyoxide in a mass ratio of 26:6, and the rest are the same as those in Example 5.

[0082] The solid waste co-regeneration process of the biomass phosphogypsum recycled material in this embodiment is the same as that in Example 5.

[0083] The application of the biomass phosphogypsum recycled material in this embodiment is the same as that in Example 5.

[0084] Example 8

[0085] The difference between the biomass phosphogypsum recycled material in this embodiment and that in Example 5 is that: the hydroxyoxides in the raw materials are composed of iron hydroxyoxide and aluminum hydroxyoxide in a mass ratio of 20:9.5, and the rest are the same as those in Example 5.

[0086] The solid waste co-regeneration process of the biomass phosphogypsum recycled material in this embodiment is the same as that in Example 5.

[0087] The application of the biomass phosphogypsum recycled material in this embodiment is the same as that in Example 5.

[0088] Example 9

[0089] The difference between the biomass phosphogypsum recycled material in this embodiment and that in Example 5 is that: the hydroxyoxides in the raw materials are composed of iron hydroxyoxide and aluminum hydroxyoxide in a mass ratio of 23.5:8, and the rest are the same as those in Example 5.

[0090] The solid waste co-regeneration process of the biomass phosphogypsum recycled material in this embodiment is the same as that in Example 5.

[0091] The application of the biomass phosphogypsum recycled material in this embodiment is the same as that in Example 5.

[0092] Example 10

[0093] The difference between the biomass phosphogypsum recycled material in this embodiment and that in Example 9 is that: the raw materials further include 1.5 kg of molybdenum disulfide, and the rest are the same as those in Example 9.

[0094] The solid waste co-regeneration process of the biomass phosphogypsum recycled material in this embodiment is the same as that in Example 9.

[0095] The application of the biomass phosphogypsum recycled material in this embodiment is the same as that in Example 9.

[0096] Example 11

[0097] The biomass phosphogypsum recycled material of this example is different from that of Example 9 in that: the raw materials further include 2.2 kg of molybdenum disulfide, and the rest are the same as those in Example 9.

[0098] The solid waste co-recycling process of the biomass phosphogypsum recycled material of this example is the same as that of Example 9.

[0099] The application of the biomass phosphogypsum recycled material of this example is the same as that of Example 9.

[0100] Example 12

[0101] The solid waste co-recycling process of the biomass phosphogypsum recycled material of this example is different from that of Example 11 in that: in step S3, the high-temperature calcination includes primary calcination and secondary calcination. The primary calcination temperature is 280 °C and the calcination time is 3.5 h; the secondary calcination temperature is 460 °C and the calcination time is 25 min, and the rest are the same as those in Example 11.

[0102] The application of the biomass phosphogypsum recycled material of this example is the same as that of Example 11.

[0103] Example 13

[0104] The solid waste co-recycling process of the biomass phosphogypsum recycled material of this example is different from that of Example 11 in that: in step S3, the high-temperature calcination includes primary calcination and secondary calcination. The primary calcination temperature is 320 °C and the calcination time is 2 h; the secondary calcination temperature is 350 °C and the calcination time is 35 min, and the rest are the same as those in Example 11.

[0105] The application of the biomass phosphogypsum recycled material of this example is the same as that of Example 11.

[0106] Comparative Example

[0107] Comparative Example 1

[0108] The biomass phosphogypsum recycled material of this comparative example is made of raw materials with the following weights: 122 kg of phosphogypsum, 35 kg of biomass solid waste, 5 kg of construction waste soil, 5 kg of sludge, 1 kg of quicklime, and 5.5 kg of adsorbent.

[0109] Among them, the biomass solid waste is agricultural straw. The sludge is urban and rural sludge. The adsorbent is composed of a base material, chitosan quaternary ammonium salt, and hydroxy oxide in a mass ratio of 10:7:8. The hydroxy oxide is iron hydroxy oxide. The base material is composed of bentonite and fly ash in a mass ratio of 1:3.

[0110] The solid waste co-regeneration process of the biomass phosphogypsum recycled material in this comparative example is only different from that in Example 1 in that no promoter is added.

[0111] The application of the biomass phosphogypsum recycled material in this comparative example is the same as that in Example 1.

[0112] Comparative Example 2

[0113] The biomass phosphogypsum recycled material in this comparative example is made from the following raw materials by weight: 12 kg of phosphogypsum, 35 kg of biomass solid waste, 5 kg of construction waste soil, 5 kg of sludge, 1 kg of quicklime, 2 kg of promoter, and 5.5 kg of adsorbent.

[0114] Among them, the biomass solid waste is agricultural straw. The sludge is urban and rural sludge. The promoter is zinc chloride. The adsorbent is composed of a base material, chitosan quaternary ammonium salt, and hydroxy oxide in a mass ratio of 10:7:8. The hydroxy oxide is iron hydroxy oxide. The base material is composed of bentonite and fly ash in a mass ratio of 1:3.

[0115] The solid waste co-regeneration process of the biomass phosphogypsum recycled material in this comparative example is the same as that in Example 1.

[0116] The application of the biomass phosphogypsum recycled material in this comparative example is the same as that in Example 1.

[0117] Comparative Example 3

[0118] The biomass phosphogypsum recycled material in this comparative example is made from the following raw materials by weight: 125.5 kg of phosphogypsum, 35 kg of biomass solid waste, 5 kg of construction waste soil, 5 kg of sludge, 1 kg of quicklime, and 2 kg of promoter.

[0119] Among them, the biomass solid waste is agricultural straw. The sludge is urban and rural sludge. The promoter is composed of zinc chloride and ammonium chloride in a molar ratio of 2:1.

[0120] The solid waste co-regeneration process of the biomass phosphogypsum recycled material in this comparative example is only different from that in Example 1 in that no adsorbent is added.

[0121] The application of the biomass phosphogypsum recycled material in this comparative example is the same as that in Example 1.

[0122] Comparative Example 4

[0123] The biomass phosphogypsum recycled material in this comparative example is made from the following raw materials by weight: 120 kg of phosphogypsum, 35 kg of biomass solid waste, 5 kg of construction waste soil, 5 kg of sludge, 1 kg of quicklime, 2 kg of promoter, and 5.5 kg of adsorbent.

[0124] Among them, the biomass solid waste is agricultural straw. The sludge is urban and rural sludge. The promoter is composed of zinc chloride and ammonium chloride in a molar ratio of 2:1.

[0125] The adsorbent is composed of bentonite and fly ash in a mass ratio of 1:3.

[0126] The solid waste co-regeneration process of the biomass phosphogypsum recycled material in this comparative example is the same as that in Example 1.

[0127] The application of the biomass phosphogypsum recycled material in this comparative example is the same as that in Example 1.

[0128] Comparative Example 5

[0129] The biomass phosphogypsum recycled material in this comparative example is made from the following raw materials by weight: 120 kg of phosphogypsum, 35 kg of biomass solid waste, 5 kg of construction waste soil, 5 kg of sludge, 1 kg of quicklime, 2 kg of accelerator, and 5.5 kg of adsorbent.

[0130] Among them, the biomass solid waste is agricultural straw. The sludge is urban and rural sludge. The accelerator is composed of zinc chloride and ammonium chloride in a molar ratio of 2:1.

[0131] The adsorbent is composed of a base material and hydroxyoxide in a mass ratio of 10:8. The hydroxyoxide is iron oxyhydroxide. The base material is composed of bentonite and fly ash in a mass ratio of 1:3.

[0132] The solid waste co-regeneration process of the biomass phosphogypsum recycled material in this comparative example is the same as that in Example 1.

[0133] The application of the biomass phosphogypsum recycled material in this comparative example is the same as that in Example 1.

[0134] Comparative Example 6

[0135] The biomass phosphogypsum recycled material in this comparative example is made from the following raw materials by weight: 120 kg of phosphogypsum, 35 kg of biomass solid waste, 5 kg of construction waste soil, 5 kg of sludge, 1 kg of quicklime, 2 kg of accelerator, and 5.5 kg of adsorbent.

[0136] Among them, the biomass solid waste is agricultural straw. The sludge is urban and rural sludge. The accelerator is composed of zinc chloride and ammonium chloride in a molar ratio of 2:1.

[0137] The adsorbent is composed of a base material and chitosan quaternary ammonium salt in a mass ratio of 10:7. The base material is composed of bentonite and fly ash in a mass ratio of 1:3.

[0138] The solid waste co-regeneration process of the biomass phosphogypsum recycled material in this comparative example is the same as that in Example 1.

[0139] The application of the biomass phosphogypsum recycled material in this comparative example is the same as that in Example 1.

[0140] Comparative Example 7

[0141] The biomass phosphogypsum recycled material of this comparative example is made from raw materials with the following weights: 120 kg of phosphogypsum, 35 kg of biomass solid waste, 5 kg of construction waste soil, 5 kg of sludge, 1 kg of quicklime, 2 kg of promoter, and 5.5 kg of adsorbent.

[0142] Among them, the biomass solid waste is agricultural straw. The sludge is urban and rural sludge. The promoter is composed of zinc chloride and ammonium chloride at a molar ratio of 2:1.

[0143] The adsorbent is composed of chitosan quaternary ammonium salt and hydroxyoxide at a mass ratio of 7:8. The hydroxyoxide is iron hydroxyoxide.

[0144] The solid waste co-regeneration process of the biomass phosphogypsum recycled material in this comparative example is the same as that in Example 1.

[0145] The application of the biomass phosphogypsum recycled material in this comparative example is the same as that in Example 1.

[0146] Comparative Example 8

[0147] The biomass phosphogypsum recycled material of this comparative example is made from raw materials with the following weights: 120 kg of phosphogypsum, 35 kg of biomass solid waste, 5 kg of construction waste soil, 5 kg of sludge, 1 kg of quicklime, 2 kg of promoter, and 5.5 kg of adsorbent.

[0148] Among them, the biomass solid waste is agricultural straw. The sludge is urban and rural sludge. The promoter is composed of zinc chloride and ammonium chloride at a molar ratio of 2:1.

[0149] The adsorbent is composed of base material and titanium dioxide at a mass ratio of 10:8. The hydroxyoxide is iron hydroxyoxide. The base material is composed of bentonite and fly ash at a mass ratio of 1:3.

[0150] The solid waste co-regeneration process of the biomass phosphogypsum recycled material in this comparative example is the same as that in Example 1.

[0151] The application of the biomass phosphogypsum recycled material in this comparative example is the same as that in Example 1.

[0152] Performance detection test

[0153] Detection method

[0154] Take the biomass phosphogypsum recycled materials of Examples 1 - 13 and Comparative Examples 1 - 8 and divide them into two equal parts. One part is placed at room temperature, and the other part is put into a constant temperature steam curing box with the temperature set at 80 °C. After steam curing for 72 h, take them out, and then conduct leaching tests in accordance with HJ / T299 - 2007. Evaluate the heavy metal release amount according to the change degree of the heavy metal concentration (mg / L) in the leachate. The test results are shown in Table 1.

[0155] Table 1 Performance test data of the biomass phosphogypsum recycled materials in Examples 1-13 and Comparative Examples 1-8

[0156]

[0157] Analysis of Examples 1-3 and Comparative Examples 1-3 and in combination with Table 1 shows that when the biomass solid waste and phosphogypsum are co-calcined and recycled in a high-temperature kiln, the biochar generated from the biomass solid waste can serve as a carrier, enabling the adsorbent to complex and chelate with heavy metal components to form an adsorbent body that can adsorb into the biochar. At the same time, the base material components seal the mesoporous structure on the surface of the biochar, greatly reducing the release amount of heavy metals during the use of the recycled material. It can be seen that the Pb content after 72-hour steam curing treatment in Example 3 only increases from 0.326 mg / L to 0.653 mg / L, while in Comparative Example 3, it increases from the original 1.269 mg / L to 2.561 mg / L. Thus, it can be seen that the release amount of heavy metal components during the use of the recycled material is greatly reduced.

[0158] Analysis of Examples 4-9 and Comparative Examples 4-8 and in combination with Table 1 shows that by further optimizing and adjusting the composition ratio of the adsorbent, enhancing the complexing and chelating ability with heavy metal components, and reducing the desorption of heavy metal ions, the Pb content after 72-hour steam curing treatment in Example 9 is only 0.249 mg / L. In Comparative Example 4, only bentonite and fly ash are used as the adsorbent, and the Pb content after 72-hour steam curing treatment is as high as 3.565 mg / L. Analysis of Comparative Example 5 and Comparative Example 6 shows that when the base material remains unchanged, it can be seen that the adsorption effect of chitosan quaternary ammonium salt is better. In Comparative Example 7, no base material is added, and only hydroxyoxides and chitosan quaternary ammonium salt are selected. Perhaps due to the lack of coating and sealing on the surface of the biomass, heavy metal components are easily released back. In Comparative Example 8, when the base material and titanium dioxide are used as the adsorbent, the Pb content after 72-hour steam curing treatment is as high as 1.521 mg / L, and its adsorption and release inhibition effect is much smaller than that of Example 9. It can be seen that the adsorbent, promoter, and biomass solid waste in this application can obtain a recycled material with safety, environmental protection, and a low release rate of heavy metal components after co-regeneration with phosphogypsum.

[0159] Analysis of Example 10, Example 11, Examples 12-13 and in combination with Table 1 shows that by adding molybdenum disulfide and optimizing the calcination process, the mesoporous structure of the biochar can be further improved, and the stability of the coating body can be enhanced. It can be seen that the Pb content after 72-hour steam curing treatment in Example 12 only increases from 0.201 mg / L to 0.218 mg / L, and the release amount of heavy metals is further reduced.

[0160] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A biomass phosphogypsum recycled material, characterized in that, It is mainly made of the following raw materials in parts by weight: 80 - 120 parts of phosphogypsum, 35 - 50 parts of biomass solid waste, 5 - 7 parts of construction waste soil, 2 - 5 parts of sludge, 1 - 3 parts of quicklime, 2 - 3.5 parts of accelerator, and 5.5 - 8 parts of adsorbent; the accelerator is composed of zinc chloride and ammonium chloride in a molar ratio of (2 - 3):(0.5 - 1); the adsorbent is composed of a base material, chitosan quaternary ammonium salt, and hydroxyoxide in a mass ratio of (10 - 18):(7 - 15):(3 - 8). The solid waste co - regeneration process of the biomass phosphogypsum recycled material includes the following steps: S1: Sort the biomass solid waste to remove metals and plastics for later use; S2: Crush and screen the phosphogypsum for later use; S3: Take the biomass solid waste, phosphogypsum, construction waste soil, sludge, quicklime, accelerator, and adsorbent in the formula amounts, mix them evenly, add them into a high - temperature kiln, and carry out anoxic high - temperature calcination, regeneration, and cooling; The high - temperature calcination includes primary calcination and secondary calcination. The primary calcination temperature is 280 - 320 °C, and the calcination time is 2 - 3.5 h; the secondary calcination temperature is 350 - 460 °C, and the calcination time is 25 - 35 min.

2. The biomass phosphogypsum recycled material according to claim 1, wherein The hydroxyoxide is at least one of iron hydroxyoxide, nickel hydroxyoxide, aluminum hydroxyoxide, and manganese hydroxyoxide.

3. A biomass phosphogypsum recycled material according to claim 2, wherein The hydroxyoxide is composed of iron hydroxyoxide and aluminum hydroxyoxide in a molar ratio of (20 - 26):(6 - 9.5).

4. A biomass phosphogypsum recycled material according to claim 1, wherein The base material is at least one of clay, bentonite, and fly ash.

5. A biomass phosphogypsum recycled material according to claim 1, wherein, The mass ratio of the adsorbent to the accelerator is (2.34 - 2.75):

1.

6. The biomass phosphogypsum recycled material according to claim 1, wherein The raw materials also include 1.5 - 2.2 parts by weight of molybdenum disulfide.

7. A biomass phosphogypsum recycled material according to claim 1, characterized in that, The step of adding molybdenum disulfide is also included in step S3.

8. An application of the biomass phosphogypsum recycled material as described in claim 1, characterized in that, It is used for soil improvement, agricultural production, sewage treatment, and construction.

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