A process for preparing magnesium ammonium phosphate monohydrate from potassium phytate hydrolysis residue.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-26
- Publication Date
- 2026-08-14
AI Technical Summary
现阶段行业内对植酸钾水解渣的处理方式仍以简单填埋、堆存为主，不仅造成大量磷、镁有价资源的严重浪费，废渣堆积还易造成土壤、水体污染，引发二次环境问题
[0020]本发明以植酸钾水解渣为原料，加入磷酸和盐酸，经过加热搅拌反应后，过滤除去不溶物，得到的磷酸二氢镁料液经过加热，加入氨水调节pH，反应结束后过滤，收集的固相经过水洗、干燥，得到一水磷酸铵镁产品；收集的液相经过加热，加入氨水调节pH，反应结束后过滤，收集的滤液经过浓缩、结晶、干燥，得到氯化铵产品，收集的结晶母液作为工业原料使用。上述工艺方法可定向得到高纯度，高收率和高产量的一水磷酸铵镁产品，同时还可以得到氯化铵产品。该工艺方法，避免了资源浪费，降低了环境污染，实现了资源化综合利用，为企业增加了经济效益。
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Abstract
Description
Technical Field
[0001] This invention relates to the field of industrial solid waste recycling technology, and in particular to a process for preparing magnesium ammonium phosphate monohydrate using potassium phytate hydrolysis residue as raw material. Background Technology
[0002] Magnesium ammonium phosphate (commonly known as struvite) is a slow-release fertilizer containing nitrogen, phosphorus, and magnesium. Common forms include hexahydrate (MgNH4PO4·6H2O), monohydrate (MgNH4PO4·H2O), and anhydrous form (MgNH4PO4). Among these, monohydrate magnesium ammonium phosphate exhibits greater stability and more uniform nutrient release, making it more suitable for agricultural fertilization applications and thus possessing higher market value.
[0003] Currently, traditional magnesium ammonium phosphate (MgMP) preparation processes mostly use high-purity chemical reagents as raw materials. This not only results in high raw material procurement costs and poor production economics, but also relies entirely on pure chemical raw materials for synthesis, failing to achieve the recycling and reuse of industrial waste resources, leading to low resource utilization and an environmentally unfriendly production model. Meanwhile, the industrial production of potassium phytate generates a large amount of hydrolysis residue, which is rich in valuable elements such as magnesium, phosphorus, and potassium, possessing extremely high potential for resource utilization. At present, the industry's treatment of potassium phytate hydrolysis residue mainly relies on simple landfilling and stockpiling, causing a serious waste of valuable phosphorus and magnesium resources. Furthermore, the accumulation of waste residue easily leads to soil and water pollution, causing secondary environmental problems. Existing technologies rarely offer high-value preparation processes that couple the utilization of phosphorus and magnesium components in potassium phytate hydrolysis residue, failing to effectively combine this industrial waste residue with the synthesis of magnesium ammonium phosphate monohydrate, and thus failing to achieve the resource recovery of all components of the waste residue. Therefore, to address the above problems, it is necessary to develop a process for preparing magnesium ammonium phosphate monohydrate using potassium phytate hydrolysis residue as a raw material. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to provide a process for preparing magnesium ammonium phosphate monohydrate using potassium phytate hydrolysis residue as raw material, which can achieve high yield, high efficiency and high purity magnesium ammonium phosphate monohydrate product.
[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:
[0006] A process for preparing magnesium ammonium phosphate monohydrate from potassium phytate hydrolysis residue includes the following steps:
[0007] (1) Take the collected potassium phytate hydrolysis residue, add phosphoric acid and hydrochloric acid and stir, control the reaction temperature and reaction time, filter after the reaction is completed, and use the resulting liquid for later use.
[0008] (2) Take the liquid material described in step (1) and heat it. Add ammonia water and stir to adjust the pH. Control the reaction time. After the reaction is completed, filter it and collect the solid phase and liquid phase separately for later use.
[0009] (3) Take the solid phase described in step (2), wash it with water and dry it to obtain magnesium ammonium phosphate monohydrate product;
[0010] (4) Take the liquid phase described in step (2) and heat it. Add ammonia water and stir to adjust the pH. Control the reaction time. After the reaction is completed, filter it. The collected filtrate is concentrated, cooled and crystallized, and dried to obtain ammonium chloride product.
[0011] As an improved technical solution, the magnesium content in the potassium phytate hydrolysis residue in step (1) is 18-22%; the phytate hydrolysis residue, phosphoric acid and hydrochloric acid are mixed in a mass ratio of 1:0.8-1.2:0.5-0.8.
[0012] As an improved technical solution, in step (1), the reaction temperature is controlled at 60-80℃ and the reaction time is 2-4h.
[0013] As an improved technical solution, the solid phase in step (2) is heated to 50-60℃.
[0014] As an improved technical solution, the mass concentration of ammonia water in step (2) is 25-28%, the pH is adjusted to 9-10, and the reaction time is controlled to be 1-2h.
[0015] As an improved technical solution, the solid phase in step (3) is washed with water 2-3 times; the drying temperature is 60-80℃ and the drying time is 18-24h.
[0016] As an improved technical solution, the liquid phase in step (4) is heated to 40-50℃.
[0017] As an improved technical solution, the mass concentration of ammonia water in step (4) is 18-22%, the pH is adjusted to 7-8, and the reaction time is controlled to be 0.5-1h.
[0018] As an improved technical solution, the mother liquor collected by cooling and crystallization in step (4) is used as an industrial raw material.
[0019] After adopting the above technical solution, the beneficial effects of the present invention are:
[0020] This invention uses potassium phytate hydrolysis residue as raw material, adds phosphoric acid and hydrochloric acid, and after heating and stirring, removes insoluble matter by filtration. The resulting magnesium dihydrogen phosphate solution is then heated, and ammonia is added to adjust the pH. After the reaction, the solution is filtered, and the collected solid phase is washed with water and dried to obtain magnesium ammonium phosphate monohydrate. The collected liquid phase is heated, and ammonia is added to adjust the pH. After the reaction, the solution is filtered, and the collected filtrate is concentrated, crystallized, and dried to obtain ammonium chloride. The collected crystallization mother liquor is used as an industrial raw material. This process can directionally obtain high-purity, high-yield, and high-quantity magnesium ammonium phosphate monohydrate, while also producing ammonium chloride. This process avoids resource waste, reduces environmental pollution, achieves comprehensive resource utilization, and increases economic benefits for enterprises. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0022] Example 1
[0023] A process for preparing magnesium ammonium phosphate monohydrate from potassium phytate hydrolysis residue includes the following steps:
[0024] (1) Take 10 kg of potassium phytate hydrolysis residue (magnesium content is 18%), add 85 wt% phosphoric acid and 32 wt% hydrochloric acid in a mass ratio of 1:0.8:0.5 and stir. Control the reaction temperature at 60℃. After reacting for 2 hours, filter and obtain 23 kg of liquid for later use.
[0025] (2) Take 23 kg of liquid from step (1), heat it to 50°C, add 4.14 kg of ammonia water with a mass concentration of 25%, stir, adjust the pH to 9, react for 2 h, filter, and collect 9.96 kg of solid phase and 16.2 L of liquid phase for later use;
[0026] (3) Take 9.96 kg of solid phase from step (2), wash it twice with water, and dry it at 60°C for 24 h to obtain 6696 g of magnesium ammonium phosphate monohydrate product;
[0027] (4) Take 16.2L of liquid phase from step (2), heat it to 40℃, add 4.4L of ammonia water with a mass concentration of 18%, stir, adjust the pH to 7, react for 0.5h, filter, collect 20.6L of filtrate, concentrate it under -0.09Mpa and 85℃ to obtain 5.2L of concentrate with a solid content of 45%, cool it down to 30℃ to crystallize, and then dry it in a vacuum drying oven under a vacuum degree of -0.09Mpa and 60℃ for 8h to obtain 2000.9g of ammonium chloride product; the collected crystallization mother liquor is used as industrial raw material.
[0028] Example 2
[0029] A process for preparing magnesium ammonium phosphate monohydrate from potassium phytate hydrolysis residue includes the following steps:
[0030] (1) Take 10 kg of collected potassium phytate hydrolysis residue (magnesium content is 20%), add 85 wt% phosphoric acid and 32 wt% hydrochloric acid in a mass ratio of 1:1.0:0.65, stir, control the reaction temperature at 70℃, filter after reaction for 3 h, and use the 26.5 kg of liquid material for later use.
[0031] (2) Take 26.5 kg of the liquid from step (1), heat it to 55°C, add 4.6 kg of ammonia water with a mass concentration of 26.5%, stir, adjust the pH to 9.5, react for 1.5 h, filter, and collect 10.1 kg of solid phase and 19.9 L of liquid phase for later use.
[0032] (3) Take 10.1 kg of solid phase from step (2), wash it with water 3 times, and dry it at 70°C for 21 h to obtain 7.6 kg of magnesium ammonium phosphate monohydrate product;
[0033] (4) Take 19.9L of liquid phase from step (2), heat it to 45℃, add 5.7L of ammonia water with a mass concentration of 20%, stir, adjust the pH to 7.5, react for 0.8h, filter, collect 25.6L of filtrate, concentrate it under -0.09Mpa and 85℃ to obtain 6.3L of concentrated solution with a solid content of 45%, cool it down to 30℃ to crystallize, and then dry it in a vacuum drying oven under a vacuum degree of -0.09Mpa and 65℃ for 6h to obtain 2634g of ammonium chloride product; the collected crystallization mother liquor is used as industrial raw material.
[0034] Example 3
[0035] A process for preparing magnesium ammonium phosphate monohydrate from potassium phytate hydrolysis residue includes the following steps:
[0036] (1) Take 10 kg of potassium phytate hydrolysis residue (magnesium content is 22%), add 85 wt% phosphoric acid and 32 wt% hydrochloric acid in a mass ratio of 1:1.2:0.8 and stir. Control the reaction temperature at 80℃. After reacting for 4 hours, filter and obtain 30.0 kg of liquid for later use.
[0037] (2) Take 30.0 kg of the liquid from step (1), heat it to 60°C, add 5.06 kg of ammonia water with a mass concentration of 28%, stir, adjust the pH to 10, react for 2 hours, filter, and collect 11.2 kg of solid phase and 22.7 L of liquid phase for later use.
[0038] (3) Take 11.2 kg of the solid phase from step (2), wash it twice with water, and dry it at 80°C for 18 h to obtain 8624 g of magnesium ammonium phosphate monohydrate product;
[0039] (4) Take 22.7L of liquid phase from step (2), heat it to 50℃, add 5.72L of ammonia water with a mass concentration of 22%, stir, adjust the pH to 8, react for 1h, filter, collect 28.42L of filtrate, concentrate it under -0.09Mpa and 85℃ to obtain 6.8L of concentrated solution with a solid content of 45%, cool it down to 30℃ to crystallize, and then dry it in a vacuum drying oven under a vacuum degree of -0.09Mpa and 70℃ for 4h to obtain 2530.8g of ammonium chloride product; the collected crystallization mother liquor is used as industrial raw material.
[0040] To better demonstrate that the process of the present invention can produce high-purity, high-yield, and high-output magnesium ammonium phosphate monohydrate, 14 comparative examples are provided with reference to Example 3, as detailed below.
[0041] Comparative Example 1
[0042] Unlike Example 3, the reaction temperature was controlled at 55°C in step (1), while the rest of the operation was the same.
[0043] Comparative Example 2
[0044] Unlike Example 3, the reaction temperature was controlled at 85°C in step (1), while the rest of the operation was the same.
[0045] Comparative Example 3
[0046] Unlike Example 3, the reaction temperature was controlled at 45°C in step (2), while the rest of the operation was the same.
[0047] Comparative Example 4
[0048] Unlike Example 3, the reaction temperature was controlled at 65°C in step (2), while the rest of the operation was the same.
[0049] Comparative Example 5
[0050] Unlike Example 3, in step (2), the reaction pH was controlled at 8.5, while the rest of the operation was the same.
[0051] Comparative Example 6
[0052] Unlike Example 3, in step (2), the reaction pH was controlled at 10.5, while the rest of the operation was the same.
[0053] Comparative Example 7
[0054] Unlike Example 3, the drying temperature in step (3) is 50°C, while the rest of the operation is the same.
[0055] Comparative Example 8
[0056] Unlike Example 3, the drying temperature in step (3) is 90°C, while the rest of the operation is the same.
[0057] Comparative Example 9
[0058] Unlike Example 3, the drying time in step (3) is 15 hours, while the rest of the operation is the same.
[0059] Comparative Example 10
[0060] Unlike Example 3, the drying time in step (3) is 27 hours, while the rest of the operation is the same.
[0061] Comparative Example 11
[0062] Unlike Example 3, in step (4), the temperature is heated to 35°C, while the rest of the operation is the same.
[0063] Comparative Example 12
[0064] Unlike Example 3, in step (4), the temperature is raised to 55°C, while the rest of the operation is the same.
[0065] Comparative Example 13
[0066] Unlike Example 3, in step (4), the reaction pH is controlled at 6.5, while the rest of the operation is the same.
[0067] Comparative Example 14
[0068] Unlike Example 3, in step (4), the reaction pH is controlled at 8.5, while the rest of the operation is the same.
[0069]
[0070] The data in Table 1 shows that the yield, purity, and overall quality of magnesium ammonium phosphate monohydrate prepared using the process of Example 3 of this invention are superior to those of other examples and comparative examples.
[0071] It should be noted that the X-ray diffraction characteristic peaks of the magnesium ammonium phosphate monohydrate prepared by this invention match those of the magnesium ammonium phosphate monohydrate standard card JCPDS No. 01-076-0885. The product exhibits characteristic diffraction peaks specific to magnesium ammonium phosphate monohydrate at 2θ = 11.7°, 20.8°, 29.3°, 31.5°, and 35.6°, with small peak position deviations and complete peak shapes. The characteristic peaks of magnesium ammonium phosphate heptahydrate (JCPDS No. 01-077-2303) and the diffraction peaks of raw material impurities do not appear in the spectrum, proving that the magnesium ammonium phosphate monohydrate prepared in Examples 1-3 of this invention is magnesium ammonium phosphate monohydrate.
[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A process for preparing magnesium ammonium phosphate monohydrate from potassium phytate hydrolysis residue, characterized in that, Includes the following steps: (1) Take the collected potassium phytate hydrolysis residue, add phosphoric acid and hydrochloric acid and stir, control the reaction temperature and reaction time, filter after the reaction is completed, and use the resulting liquid for later use. (2) Take the liquid material described in step (1) and heat it. Add ammonia water and stir to adjust the pH. Control the reaction time. After the reaction is completed, filter it and collect the solid phase and liquid phase separately for later use. (3) Take the solid phase described in step (2), wash it with water and dry it to obtain magnesium ammonium phosphate monohydrate product; (4) Take the liquid phase described in step (2) and heat it. Add ammonia water and stir to adjust the pH. Control the reaction time. After the reaction is completed, filter it. The collected filtrate is concentrated, cooled and crystallized, and dried to obtain ammonium chloride product.
2. The process for preparing magnesium ammonium phosphate monohydrate using potassium phytate hydrolysis residue as raw material according to claim 1, characterized in that, In step (1), the magnesium content in the potassium phytate hydrolysis residue is 18-22%; the phytate hydrolysis residue, phosphoric acid and hydrochloric acid are mixed in a mass ratio of 1:0.8-1.2:0.5-0.
8.
3. The process for preparing magnesium ammonium phosphate monohydrate from potassium phytate hydrolysis residue according to claim 1, characterized in that, In step (1), the reaction temperature is controlled at 60-80℃ and the reaction time is 2-4h.
4. The process for preparing magnesium ammonium phosphate monohydrate from potassium phytate hydrolysis residue according to claim 1, characterized in that, The solid phase described in step (2) is heated to 50-60°C.
5. The process for preparing magnesium ammonium phosphate monohydrate from potassium phytate hydrolysis residue according to claim 1, characterized in that, The mass concentration of ammonia water in step (2) is 25-28%, and the pH is adjusted to 9-10; the reaction time is controlled to be 1-2 hours.
6. The process for preparing magnesium ammonium phosphate monohydrate from potassium phytate hydrolysis residue according to claim 1, characterized in that, The solid phase described in step (3) is washed with water 2-3 times; the drying temperature is 60-80℃ and the drying time is 18-24h.
7. The process for preparing magnesium ammonium phosphate monohydrate from potassium phytate hydrolysis residue according to claim 1, characterized in that, The liquid phase in step (4) is heated to 40-50°C.
8. The process for preparing magnesium ammonium phosphate monohydrate from potassium phytate hydrolysis residue according to claim 1, characterized in that, The mass concentration of ammonia water in step (4) is 18-22%, and the pH is adjusted to 7-8; the reaction time is controlled to be 0.5-1h.
9. The process for preparing magnesium ammonium phosphate monohydrate from potassium phytate hydrolysis residue according to claim 1, characterized in that, The mother liquor collected during cooling and crystallization in step (4) is used as an industrial raw material.