Process method for preparing magnesium dihydrogen phosphate from inositol hydrolysis residues

Abstract

The invention relates to the technical field of inositol production, in particular to a process method for preparing magnesium dihydrogen phosphate from inositol hydrolysis residues, which comprises the following steps: by taking the inositol hydrolysis residues as raw materials, adding phosphoric acid to adjust the pH value to be acidic, adding water, heating, stirring and dissolving, then adding activated carbon for decoloration treatment, filtering, and cooling and crystallizing the collected filtrate to obtain magnesium dihydrogen phosphate. And washing and drying the collected crystals to obtain the monopotassium phosphate product. According to the technological method, magnesium ions and phosphoric acid in the inositol hydrolysis residues can be recycled, the monopotassium phosphate product with high yield, high yield, high purity and good color is obtained, resource waste is effectively avoided, and new economic benefits are increased for enterprises.

Description

Technical Field

[0001] The present invention relates to the technical field of inositol production, and particularly relates to a process for preparing magnesium dihydrogen phosphate using inositol hydrolysis residue. Background Art

[0002] Using corn steep liquor as raw material, potassium phytate obtained after resin column adsorption, desorption and other treatments is hydrolyzed and filtered. The collected hydrolysis filtrate is further processed to obtain inositol; the collected filter residue (inositol hydrolysis residue) contains minerals such as calcium and magnesium, and also contains some hydrolysis by-products (such as phosphoric acid, organic acids). The minerals exist in the hydrolysis residue in the form of phosphates combined with phosphoric acid. At present, most of the hydrolysis residues are discarded and not comprehensively utilized enough, which not only causes waste of resources, but also may exert certain pressure on the environment.

[0003] Magnesium dihydrogen phosphate has important applications in the fields of fireproof materials, fertilizers, food additives, etc. Traditional methods for producing magnesium dihydrogen phosphate have problems such as high raw material costs, complex processes or certain impacts on the environment. For example, Patent CN1234567A mentions a production method using pure chemical reagents as raw materials. Although the product purity is high, the raw material cost is high, the production process is complex, and it has a certain impact on the environment. If the phosphates in the inositol hydrolysis residue can be recycled and used to produce magnesium dihydrogen phosphate products, it will surely increase new economic benefits and obtain a new source of magnesium dihydrogen phosphate products. Therefore, in view of the above problems, it is necessary to develop a process for preparing magnesium dihydrogen phosphate using inositol hydrolysis residue. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: aiming at the deficiencies of the prior art, to provide a process for preparing magnesium dihydrogen phosphate using inositol hydrolysis residue, and high-yield, high-recovery and high-purity magnesium dihydrogen phosphate products can be obtained by using this process.

[0005] To solve the above technical problem, the technical solution of the present invention is:

[0006] A process for preparing magnesium dihydrogen phosphate using inositol hydrolysis residue, the process comprising the following steps:

[0007] (1) Take the collected inositol hydrolysis residue, beat it into a pulp, add phosphoric acid, adjust the pH to acidic, then add purified water, heat and stir to dissolve, and reserve the obtained hydrolysis residue liquid material;

[0008] (2) Take the hydrolysis residue liquid material in step (1), add activated carbon and then adjust the pH, control the decolorization temperature and decolorization time, filter after the decolorization treatment is completed, and reserve the collected decolorized liquid;

[0009] (3) Take the decolorizing solution described in step (2), cool it for crystallization, filter it, and the collected crystals can be obtained as magnesium dihydrogen phosphate products after drying.

[0010] As an improved technical solution, the magnesium ion content in the inositol hydrolysis residue in step (1) is 20-25%.

[0011] As an improved technical solution, the concentration of phosphoric acid in step (1) is 75-85 wt%, and the pH is adjusted to 3-3.5.

[0012] As an improved technical solution, the inositol hydrolysis residue and purified water are added in a ratio of 1:1-3 of the feed liquid ratio in step (1).

[0013] As an improved technical solution, it is heated to 75-90 °C in step (1) and stirred at a stirring speed of 5000-10000 rpm for 30-60 min.

[0014] As an improved technical solution, the addition amount of the activated carbon in step (2) is 1-5‰ of the dry weight of the inositol hydrolysis residue, the specific surface area of the activated carbon is 1000-1500 m² / g, and the pore diameter of the activated carbon is 10-30 nm.

[0015] As an improved technical solution, the pH is adjusted to 2-2.5 in step (2), the decolorization temperature is controlled at 50-70 °C, and the decolorization time is 30-60 min.

[0016] As an improved technical solution, it is cooled to 20-30 °C in step (3).

[0017] After adopting the above technical solution, the beneficial effects of the present invention are:

[0018] The present invention uses inositol hydrolysis residue as raw material, adds phosphoric acid to adjust the pH to acidic, adds water and heats and stirs to dissolve, then adds activated carbon for decolorization treatment, the filtrate collected after filtration is cooled for crystallization, and the collected crystals are washed and dried to obtain potassium dihydrogen phosphate products. The above process method can recycle magnesium ions and phosphoric acid in the inositol hydrolysis residue, obtain potassium dihydrogen phosphate products with high yield, high recovery rate, high purity and good color, effectively avoid resource waste, and increase new economic benefits for enterprises. Specific Embodiments

[0019] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0020] Example 1

[0021] A process for preparing magnesium dihydrogen phosphate using inositol hydrolysis residue, comprising the following steps:

[0022] (1) Take 1000 g of collected inositol hydrolysis residue (magnesium ion content is 20%), after pulping, add 75 wt% phosphoric acid to adjust the pH to 3, add purified water according to the ratio of solid-liquid ratio of 1:1, heat to 75 °C, stir at a stirring speed of 5000 rpm for 30 min, and obtain 2063 g of hydrolysis residue slurry for standby;

[0023] (2) Take the hydrolysis residue slurry in step (1), add 0.75 g of activated carbon (specific surface area is 1000 - 1500 ㎡ / g, pore size is 10 - 30 nm) which is 1‰ of the dry weight of the inositol hydrolysis residue, adjust the pH to 2, control the decolorization temperature at 50 °C, after decolorization treatment for 30 min, filter, and collect 2.06 L of decolorized liquid for standby;

[0024] (3) Take 2.06 L of the decolorized liquid in step (2), cool down to 20 °C for crystallization and filtration, and the collected crystals can be obtained as magnesium dihydrogen phosphate product after drying.

[0025] Example 2

[0026] A process for preparing magnesium dihydrogen phosphate using inositol hydrolysis residue, comprising the following steps:

[0027] (1) Take 1000 g of collected inositol hydrolysis residue (magnesium ion content is 22%), after pulping, add 78 wt% phosphoric acid to adjust the pH to 3.2, add purified water according to the ratio of solid-liquid ratio of 1:1.5, heat to 78 °C, stir at a stirring speed of 6500 rpm for 38 min, and obtain 2590 g of hydrolysis residue slurry for standby;

[0028] (2) Take the hydrolysis residue slurry in step (1), add 1.6 g of activated carbon (specific surface area is 1000 - 1500 ㎡ / g, pore size is 10 - 30 nm) which is 2‰ of the dry weight of the inositol hydrolysis residue, adjust the pH to 2.2, control the decolorization temperature at 55 °C, after decolorization treatment for 40 min, filter, and collect 2.55 L of decolorized liquid for standby;

[0029] (3) Take 2.55 L of the decolorized liquid in step (2), cool down to 23 °C for crystallization and filtration, and the collected crystals can be obtained as magnesium dihydrogen phosphate product after drying.

[0030] Example 3

[0031] A process for preparing magnesium dihydrogen phosphate using inositol hydrolysis residue, comprising the following steps:

[0032] (1) Take 1000 g of the collected inositol hydrolysis residue (with a magnesium ion content of 25%), make it into a pulp, add phosphoric acid with a concentration of 80 wt% to adjust the pH to 3.5, add purified water according to the ratio of solid-liquid ratio of 1:2, heat to 85 °C, and stir at a stirring speed of 7500 rpm for 45 min. The obtained hydrolysis residue liquid of 3075 g is reserved for use;

[0033] (2) Take the hydrolysis residue liquid in step (1), add 2.4 g of activated carbon (specific surface area of 1000 - 1500 m² / g, pore diameter of 10 - 30 nm) which is 3‰ of the dry weight of the inositol hydrolysis residue, adjust the pH to 2.5, control the decolorization temperature at 60 °C, filter after decolorization treatment for 50 min, and collect 3.1 L of the decolorized liquid for use;

[0034] (3) Take 3.1 L of the decolorized liquid in step (2), cool it to 25 °C for crystallization and filtration. The collected crystals can be obtained as magnesium dihydrogen phosphate products after drying.

[0035] Example 4

[0036] A process for preparing magnesium dihydrogen phosphate using inositol hydrolysis residue, comprising the following steps:

[0037] (1) Take 1000 g of the collected inositol hydrolysis residue (with a magnesium ion content of 28%), make it into a pulp, add phosphoric acid with a concentration of 82 wt% to adjust the pH to 3.5, add purified water according to the ratio of solid-liquid ratio of 1:2.5, heat to 80 °C, and stir at a stirring speed of 8500 rpm for 55 min. The obtained hydrolysis residue liquid of 3580 g is reserved for use;

[0038] (2) Take the hydrolysis residue liquid in step (1), add 3.2 g of activated carbon (specific surface area of 1000 - 1500 m² / g, pore diameter of 10 - 30 nm) which is 4‰ of the dry weight of the inositol hydrolysis residue, adjust the pH to 2.5, control the decolorization temperature at 65 °C, filter after decolorization treatment for 55 min, and collect 3.55 L of the decolorized liquid for use;

[0039] (3) Take 3.55 L of the decolorized liquid in step (2), cool it to 28 °C for crystallization and filtration. The collected crystals can be obtained as magnesium dihydrogen phosphate products after drying.

[0040] Example 5

[0041] A process for preparing magnesium dihydrogen phosphate using inositol hydrolysis residue, comprising the following steps:

[0042] (1) Take 1000 g of the collected inositol hydrolysis residue (with a magnesium ion content of 30%), make it into a pulp, add phosphoric acid with a concentration of 85 wt% to adjust the pH to 3.5, add purified water according to the ratio of solid-liquid ratio of 1:3, heat to 90 °C, and stir at a stirring speed of 10000 rpm for 60 min. The obtained hydrolysis residue liquid of 4072 g is reserved for use;

[0043] (2) Take the hydrolyzed residue liquid in step (1), add 3.5 g of activated carbon (specific surface area of 1000 - 1500 ㎡ / g, pore size of 10 - 30 nm) which is 5‰ of the dry weight of the inositol hydrolyzed residue, adjust the pH to 2.5, control the decolorization temperature at 70 °C, filter after decolorization treatment for 30 - 60 min, and collect 4.05 L of the decolorized liquid for standby;

[0044] (3) Take 4.05 L of the decolorized liquid in step (2), cool it to 30 °C for crystallization and filtration, and the collected crystals can be obtained as magnesium dihydrogen phosphate products after drying.

[0045] To better prove that the process method of the present invention can obtain magnesium dihydrogen phosphate products with high yield, high recovery rate and high purity, the following comparative examples are given with reference to Example 3. The specific details of the yield, recovery rate, purity and color of magnesium dihydrogen phosphate in Examples 1 - 5 and the comparative examples are shown in Table 1.

[0046] Comparative Example 1

[0047] Different from Example 3, in step (1), 70 wt% phosphoric acid is added to adjust the pH, and the rest of the operations are the same.

[0048] Comparative Example 2

[0049] Different from Example 3, in step (1), 90 wt% phosphoric acid is added to adjust the pH, and the rest of the operations are the same.

[0050] Comparative Example 3

[0051] Different from Example 3, in step (1), the pH is adjusted to 2.5, and the rest of the operations are the same.

[0052] Comparative Example 4

[0053] Different from Example 3, in step (1), the pH is adjusted to 4, and the rest of the operations are the same.

[0054] Comparative Example 5

[0055] Different from Example 3, in step (1), it is heated to 95 °C, and the rest of the operations are the same.

[0056] Comparative Example 6

[0057] Different from Example 3, in step (2), the decolorization temperature is controlled at 45 °C, and the rest of the operations are different.

[0058] Comparative Example 7

[0059] Different from Example 3, in step (2), the decolorization temperature is controlled at 75 °C, and the rest of the operations are different.

[0060] Comparative Example 8

[0061] Different from Example 3, in step (2), the pH is controlled to be 1.5, and the rest of the operations are different.

[0062] Comparative Example 9

[0063] Different from Example 3, in step (2), the pH is controlled to be 3, and the rest of the operations are different.

[0064] Comparative Example 10

[0065] Different from Example 3, in step (2), the specific surface area of the activated carbon is 800 m² / g, and the rest of the operations are different.

[0066] Comparative Example 11

[0067] Different from Example 3, in step (2), the specific surface area of the activated carbon is 1700 m² / g, and the rest of the operations are different.

[0068] Comparative Example 12

[0069] Different from Example 3, in step (2), the pore diameter of the activated carbon is greater than 30 nm, and the rest of the operations are the same.

[0070] Comparative Example 13

[0071] Different from Example 3, in step (2), the pore diameter of the activated carbon is less than 10 nm, and the rest of the operations are the same.

[0072] Comparative Example 14

[0073] Different from Example 3, in step (3), the temperature is lowered to 18 °C, and the rest of the operations are different.

[0074] Comparative Example 15

[0075] Different from Example 3, in step (3), the temperature is lowered to 35 °C, and the rest of the operations are different.

[0076] Comparative Example 16

[0077] Different from Example 3, after taking inositol hydrolysis residue and pulping, purified water is added, and then phosphoric acid is added to adjust the pH to 3.5, and the rest of the operations are the same.

[0078] Table 1

[0079]

[0080]

[0081] It can be found from the data in Table 1 that the comprehensive comparison of the yield, recovery rate and purity of Example 3 is better than other examples and comparative examples.

[0082] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A process for preparing magnesium dihydrogen phosphate using inositol hydrolysis residue, characterized in that, The process method includes the following steps: (1) Take the collected inositol hydrolysis residue, beat it into a pulp, add phosphoric acid, adjust the pH to acidic, then add purified water, heat and stir to dissolve, and reserve the obtained hydrolysis residue liquid; (2) Take the hydrolysis residue liquid described in step (1), add activated carbon and then adjust the pH, control the decolorization temperature and time, filter after the decolorization treatment is completed, and reserve the collected decolorized liquid; (3) Take the decolorized liquid described in step (2), cool it for crystallization, filter, and the collected crystals can be obtained as magnesium dihydrogen phosphate products after drying.

2. A process for preparing magnesium dihydrogen phosphate using inositol hydrolysis residue according to claim 1, characterized in that, In step (1), the magnesium ion content in the inositol hydrolysis residue is 20-25%.

3. A process for preparing magnesium dihydrogen phosphate using inositol hydrolysis residue according to claim 1, characterized in that, In step (1), the concentration of phosphoric acid is 75-85 wt%, and the pH is adjusted to 3-3.

5.

4. A process for preparing magnesium dihydrogen phosphate using inositol hydrolysis residue according to claim 1, characterized in that, In step (1), the inositol hydrolysis residue and purified water are added according to the ratio of the liquid ratio of 1:1-3.

5. A process for preparing magnesium dihydrogen phosphate using inositol hydrolysis residue according to claim 1, characterized in that, In step (1), heat to 75-90 °C and stir at a stirring speed of 5000-10000 rpm for 30-60 min.

6. A process for preparing magnesium dihydrogen phosphate using inositol hydrolysis residue according to claim 1, characterized in that, In step (2), the addition amount of the activated carbon is 1-5‰ of the dry weight of the inositol hydrolysis residue, the specific surface area of the activated carbon is 1000-1500 m² / g, and the pore diameter of the activated carbon is 10-30 nm.

7. A process for preparing magnesium dihydrogen phosphate using inositol hydrolysis residue according to claim 1, characterized in that, In step (2), adjust the pH to 2-2.5, control the decolorization temperature at 50-70 °C, and the decolorization time at 30-60 min.

8. A process for preparing magnesium dihydrogen phosphate using inositol hydrolysis residue according to claim 1, characterized in that, In step (3), cool down to 20-30 °C.

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