Slow-release mineralized porous composite particle as well as preparation method and application thereof

Abstract

The invention belongs to the field of mineralized materials for water purification, and discloses slow-release mineralized porous composite particles as well as a preparation method and application thereof. Comprising the following components in parts by weight: 10-40 parts of calcined dolomite, 5-20 parts of tourmaline, 30-70 parts of zeolite and 5-20 parts of a fluxing agent. The preparation method comprises the following steps: mixing calcined dolomite serving as a basic material with tourmaline and zeolite, tabletting, and calcining and forming by taking sodium carbonate as a fluxing agent to obtain porous composite particles with mesopores as main pores and macropores as auxiliary pores. The porous composite particle has a stable mineral element slow release rate, can meet the requirements of drinking water mineralization treatment and drinking water taste improvement, has an excellent ion regulation and control capability, can effectively prevent excessive dissolution of heavy metal elements, harmful elements and hardness ions, is high in safety, does not have a scaling risk, and is suitable for popularization and application. The device is suitable for household direct drinking water, water outlet of a water purifier and other scenes. The raw material source is wide, the preparation process is simple, convenient and controllable, and the application prospect is wide.

Description

A slow-release mineralized porous composite particle, its preparation method and application Technical Field

[0001] This invention relates to the field of mineralized materials for water purification, specifically to a slow-release mineralized porous composite particle, its preparation method, and its application. Background Technology

[0002] Water is essential for human life. In addition to maintaining normal hydration, it also provides the body with the minerals needed, accounting for about 10-20% of the body's required minerals. The minerals in drinking water have a high absorption and utilization rate, making them an important source of minerals when food intake is insufficient.

[0003] Currently, most water purifiers and commercially available drinking water on the market are low-mineral water, with purified water having extremely low mineral content. Long-term consumption of low-mineral water may cause various health problems. Meanwhile, most studies suggest that drinking water taste satisfaction is directly related to water quality indicators, including sodium, potassium, magnesium, calcium, chloride, sulfate, and bicarbonate ions. Calcium, sodium, magnesium, and potassium are the four key elements affecting the taste of drinking water. Appropriate limits for calcium and magnesium ions, as well as low concentrations of potassium and sodium ions, can provide a crisp and sweet taste, but the exact proportions of each ion are not yet fully understood.

[0004] Current research on remineralization focuses on the utilization of natural minerals in terms of materials, exploring the leaching performance and process of more natural minerals as mineralizing filter media. Regarding leached ions, more attention is being paid to macroelements such as magnesium, and trace elements such as strontium, zinc, and metasilicic acid. In terms of application scenarios, it is gradually moving towards household drinking water and water purifier output, exploring the leaching performance of minerals under neutral conditions and their durability in meeting daily household water needs. All of these are still in the initial stages of experimentation and preliminary application. However, due to the unstable leaching of mineral filter media and its chemical inertness relative to water, the leaching of mineral elements is relatively slow. Even after activation treatment, the initial leaching of mineral filter cartridges is huge, but the subsequent leaching is negligible, making it difficult to maintain a stable release rate. Excessive calcium and magnesium ion content can easily lead to scaling, reducing the lifespan of the device and impairing the normal output water and the taste of drinking water. For example, the Chinese invention patent with application number 201880048943.8, "A method for producing mineral water from tap water and a household appliance", uses micronized ore. Although this solves the problem of chemical inertness in ore leaching, the leaching rate is uncontrollable. The Chinese invention patent with application number 202011015809.3, "A filter element of mineral filter media and a water quality mineralization method of the filter element", optimizes the leaching rate of ore by adding a carbon dioxide micro-nano bubble generator. However, this method is costly and the leached elements are concentrated in calcium and magnesium ions, which poses a high risk of scaling. The Chinese invention patent with application number 202510352951.3, "Magnesium-containing mineralized filter media, mineralized filter element and its preparation method", only focuses on the leaching of magnesium elements in the mineralized filter element and cannot improve the problem of poor taste of drinking water.

[0005] Therefore, there is an urgent need for a mineralizing material that can slowly release mineral elements to mineralize drinking water while improving its taste, effectively preventing scaling, and extending the life of the equipment. Summary of the Invention

[0006] In view of the problems of unstable leaching, easy scaling, and impact on normal water output and drinking water taste of existing remineralization technology ore filter media, the primary objective of this invention is to provide a slow-release mineralized porous composite particle that improves the taste of drinking water.

[0007] Another object of the present invention is to provide a method for preparing a slow-release mineralized porous composite particle.

[0008] Another object of the present invention is to provide the application of the above-mentioned slow-release mineralized porous composite particles, which can provide drinking water with potassium, sodium, calcium and magnesium in appropriate ranges and proportions, while improving the taste of drinking water.

[0009] The objective of this invention is achieved through the following technical solution: a slow-release mineralized porous composite particle, comprising the following components: 10-40 parts of calcined dolomite, 5-20 parts of tourmaline, 30-70 parts of zeolite, and 5-20 parts of flux.

[0010] Preferably, the slow-release mineralized porous composite particles comprise the following components: 15-40 parts of calcined dolomite, 5-15 parts of tourmaline, 40-70 parts of zeolite, and 5-15 parts of flux.

[0011] Preferably, the calcined dolomite is prepared by calcining dolomite powder at 600-800℃ for 1-3 hours.

[0012] Preferably, the zeolite is at least one of sodium-type zeolite (4A zeolite), potassium-type zeolite (3A zeolite), or calcium-sodium mixed zeolite (5A zeolite); the flux is anhydrous sodium carbonate; the particle size of the zeolite is ≤100 mesh, and the particle size of the tourmaline is ≤100 mesh.

[0013] Preferably, the pore volume of the slow-release mineralized porous composite particles is 0.02~0.06 cm³. 3 / g, specific surface area is 5~15m² 2 / g; The slow-release mineralized particles are obtained by mixing dolomite calcination, tourmaline, zeolite and flux in proportion, sieving, pressing and sintering.

[0014] Preferably, the slow-release mineralized porous composite particles have a radius of 2-4 mm and a height of 2-4 mm.

[0015] A method for preparing slow-release mineralized porous composite particles includes the following steps: (1) lightly calcining dolomite powder to obtain dolomite calcined material; (2) after pretreatment, tourmaline and zeolite are ground and mixed evenly with dolomite calcined material and flux in proportion and then sieved to obtain a mixture; (3) pressing the mixture to obtain a preform, then drying and sintering the obtained preform, followed by natural cooling, rinsing and drying to obtain slow-release mineralized porous composite particles.

[0016] Preferably, the light calcination in step (1) is as follows: under an air atmosphere, the dolomite powder is heated to 600-800℃ at a rate of 1-10℃ / min and kept at that temperature for 1-3 hours, then cooled to 100-200℃ at a rate of 1-10℃ / min, and finally cooled naturally to room temperature.

[0017] Preferably, the pretreatment in step (2) is as follows: place tourmaline or zeolite in water and stir at 100-400 r / min for 6-12 hours, changing the water 2-3 times during the period, until the difference in conductivity of the upper clear liquid between intervals does not exceed 5 µs / cm, then filter, dry the resulting filter cake, grind and sieve it for later use.

[0018] Preferably, the pressing pressure in step (3) is 1~8kN and the holding time is 1~5min; the sintering in step (3) is as follows: under an air atmosphere, the dried preform is heated to 650~1000℃ at a rate of 1~10℃ / min, held for 1~3h, then cooled to 100~200℃ at a rate of 1~10℃ / min, and finally cooled naturally to room temperature; the sintering temperature in step (3) is higher than the calcination temperature in step (1).

[0019] The rinsing and drying in step (3) involves rinsing with a flow rate of 100-300 mL / min for 10-16 hours, followed by drying at 60-80°C.

[0020] The above-mentioned slow-release mineralized porous composite particles are used in the mineralization treatment of drinking water and / or the improvement of drinking water taste.

[0021] Preferably, the amount of porous composite particles fed is 10~100 mg / mL.

[0022] Preferably, the pH of the mineralized drinking water is 7 to 8.5, wherein the Ca:Na:Mg:K ratio is 6 to 20:6 to 20:2 to 8:1, and more preferably 10 to 18:8 to 12:3 to 7:1.

[0023] Preferably, in the mineralized drinking water, Ca 2+ 4.0~10.0 mg / L, Na + 3.0~7.0 mg / L, Mg 2+ 1.0~4.0 mg / L, K + : 0.2~0.8 mg / L.

[0024] The slow-release mineralized porous composite particles of this invention use lightly calcined dolomite as the basic material. Calcium magnesium carbonate (CaMg(CO3)2) is lightly calcined and decomposed into appropriate amounts of calcium carbonate, calcium oxide, and magnesium oxide. This is then thoroughly mixed with tourmaline, zeolite, and sodium carbonate, compressed into tablets, and calcined using sodium carbonate as a flux to obtain porous composite particles with mesopores as the dominant structure and macropores as an auxiliary structure, with a pore volume of approximately 0.049860 cm³. 3 / g. The porous structure and negatively charged framework of sodium-type zeolite can serve as a basis for regulating the calcium and magnesium elements dissolved from the ore filter media with its excellent ion exchange capacity; the spontaneous permanent electric field of tourmaline can promote the activation of water, improve the exchange of water inside the particles, and thus promote the exchange and dissolution of mineral elements.

[0025] Compared with the prior art, the present invention has the following advantages and beneficial effects: (1) The present invention uses ore as raw material, which has the advantages of wide availability and low price.

[0026] (2) The porous composite particles prepared by the present invention have a considerable and stable slow release rate of mineral elements, which meets the needs of drinking water mineralization treatment and drinking water taste improvement. The pH of the treated drinking water is stable at 7 ~ 8.5, of which Ca: Na: Mg: K is about 6~20:6~20:2~8:1, which is suitable for applications such as household direct drinking water and water purifier output.

[0027] (3) The porous composite particles prepared by the present invention have excellent ion regulation capabilities, which can effectively prevent the excessive dissolution of heavy metal elements, harmful elements and hardness ions, and have high safety and no risk of scaling.

[0028] (4) The present invention adopts a method of high-temperature activation of ore and high-temperature sintering, the reaction conditions are controllable, the process is simple, and it is convenient for large-scale production and application.

[0029] Figure 1 is a schematic diagram of the radar for taste indicators in water samples; Figure 2 shows the sensory ranking and preference ranking results; Figure 3 shows the XRD analysis of the composite porous particles before and after dissolution; Figure 4 shows the BET (left) and XPS analysis (right) of the composite porous particles in Example 2; Figure 5 shows the TDS changes (left) and dissolution results (right) of the composite porous particles in Example 2 after 50 cycles.

[0030] The specific experimental methods are described in further detail below with reference to the embodiments and accompanying drawings, but the implementation of the present invention is not limited thereto. Unless otherwise specified in the embodiments of the present invention, conventional conditions or conditions recommended by the manufacturer shall be followed. All raw materials and reagents used, unless otherwise specified, are commercially available conventional products.

[0031] Example 1 (1) Take an appropriate amount of dry dolomite powder and place it in a tube furnace. Heat it to 700°C at a rate of 5°C / min in an air atmosphere and hold it for 1 hour. Then, cool it down to 200°C at a rate of 5°C / min. After stopping the program, let it cool down to room temperature naturally to obtain lightly calcined dolomite, i.e., calcined dolomite.

[0032] (2) Take an appropriate amount of dried tourmaline and put it into an appropriate amount of deionized water. Stir at 100 r / min for 12 h, changing the water 3 times during the period. After the conductivity of the supernatant is measured to be no more than 5 µs / cm at 5 min intervals, filter it. Place the filter cake in an oven at 60 ℃ to dry completely. Grind it and pass it through a 100-mesh sieve for later use.

[0033] (3) Place the dried sodium zeolite into an appropriate amount of deionized water, stir at 100 r / min for 12 h, change the water 3 times during the period, and after a 5 min interval, measure the conductivity of the supernatant. If it does not exceed 5 µs / cm, filter it. Place the filter cake in an oven at 60℃ to dry completely, grind it, and pass it through a 100-mesh sieve for later use.

[0034] (4) Take 38 parts of lightly calcined dolomite, 8 parts of tourmaline, 42 parts of sodium zeolite, and 12 parts of anhydrous sodium carbonate. Grind and mix them thoroughly and pass them through a 100-mesh sieve. Add the resulting solid mixture into a circular 9-hole mold with a radius of 4 mm and maintain it under a pressure of 1-8 kN for 1-2 min. After pressing it into a green body, place it in an oven at 60°C for drying. Then place the resulting green body in a tube furnace and heat it to 800°C at a rate of 5°C / min in an air atmosphere. Hold it at that temperature for 1 h. Then cool it down to 200°C at a rate of 5°C / min. After stopping the program, allow it to cool naturally to room temperature.

[0035] (5) After cooling, put the particles into an appropriate amount of deionized water and rinse them at a flow rate of 200 mL / min for 12 hours. After rinsing, place them in an oven at 60℃ to dry completely, and you will get a porous composite particle material with a radius of 4 mm and a height of 2~3 mm.

[0036] (6) The porous composite particles prepared in this example can be directly used for the mineralization treatment of low-mineral drinking water or pure water. After treating pure water with a feed amount of 20 mg / mL for 15 min, the pH of the treated pure water stabilized between 7 and 8.5, where Ca: Na: Mg: K was approximately 18: 12: 7: 1.

[0037] Table 1. Water quality range of porous composite particles in Example 1

[0038] Example 2 (1) The preparation process of porous composite particle material is the same as in Example 1.

[0039] (2) Raw material preparation: Take 30 parts of lightly calcined dolomite, 10 parts of tourmaline, 50 parts of sodium zeolite, and 10 parts of anhydrous sodium carbonate.

[0040] (3) The porous composite particles prepared in this example can be directly used for the mineralization treatment of low-mineral drinking water or pure water. After treating pure water with a feed amount of 20 mg / mL for 15 min, the pH of the treated pure water stabilized between 7 and 8.5, where Ca: Na: Mg: K was approximately 12: 15: 4: 1.

[0041] Table 2. Water quality range of porous composite particles in Example 2

[0042] Example 3 (1) The preparation process of porous composite particle material is the same as in Example 1.

[0043] (2) Raw material preparation: Take 15 parts of lightly calcined dolomite, 15 parts of tourmaline, 65 parts of sodium zeolite, and 5 parts of anhydrous sodium carbonate.

[0044] (3) The porous composite particles prepared in this example can be directly used for the mineralization treatment of low-mineral drinking water or pure water. After treating pure water with a feed amount of 20 mg / mL for 15 min, the pH of the treated pure water stabilized between 7 and 8.5, where Ca: Na: Mg: K was approximately 10: 8: 3: 1.

[0045] Table 3. Water quality range of porous composite particles in Example 3

[0046] The preparation process of the porous composite particle material in Comparative Example 1 (1) is the same as that in Example 1.

[0047] (2) Raw material preparation: Take 30 parts of lightly calcined dolomite, 20 parts of tourmaline, 40 parts of sodium zeolite, and 10 parts of anhydrous sodium carbonate.

[0048] (3) The porous composite particles prepared in this comparative example can be directly used for the mineralization treatment of low-mineral drinking water or pure water. After treating pure water with a feed amount of 20 mg / mL for 15 min, the pH of the treated pure water stabilized between 8 and 9, where Ca:Na:Mg:K was approximately 20:16:7:1.

[0049] Table 4. Water quality range of porous composite particles in Comparative Example 1

[0050] Comparative Example 2 (1) The preparation process of porous composite particle material is the same as that of Example 1.

[0051] (2) Raw material preparation: Take 20 parts of lightly calcined dolomite, 10 parts of tourmaline, 50 parts of sodium zeolite, and 20 parts of anhydrous sodium carbonate.

[0052] (3) The porous composite particles prepared in this comparative example can be directly used for the mineralization treatment of low-mineral drinking water or pure water. After treating pure water with a feed amount of 20 mg / mL for 15 min, the pH of the treated pure water stabilized between 8.5 and 9.5, where Ca: Na: Mg: K was approximately 7:14:3:1.

[0053] Table 5. Water quality range of porous composite particles in Comparative Example 2

[0054] The preparation process of the porous composite particle material in Comparative Example 3 (1) is the same as that in Example 1.

[0055] (2) Raw material preparation: Take 30 parts of lightly calcined dolomite, 0 parts of tourmaline, 60 parts of sodium zeolite, and 10 parts of anhydrous sodium carbonate.

[0056] (3) The porous composite particles prepared in this comparative example can be directly used for the mineralization treatment of low-mineral drinking water or pure water. After treating pure water with a feed amount of 20 mg / mL for 15 min, the pH of the treated pure water stabilized between 8 and 9.5, where Ca:Na:Mg:K was approximately 11:10:4:1.

[0057] Table 6. Comparative Example 3: Effluent water quality range of porous composite particles.

[0058] The preparation process of the porous composite particle material in Comparative Example 4 (1) is the same as that in Example 1.

[0059] (2) Raw material preparation: Take 40 parts of lightly calcined dolomite, 10 parts of tourmaline, 50 parts of sodium zeolite, and 0 parts of anhydrous sodium carbonate.

[0060] (3) The porous composite particles prepared in this comparative example can be directly used for the mineralization treatment of low-mineral drinking water or pure water. After treating pure water with a feed amount of 20 mg / mL for 15 min, the pH of the treated pure water stabilized between 8.5 and 10, where Ca:Na:Mg:K was approximately 13:5:5:1.

[0061] Table 7 Comparative Example 4: Effluent water quality range of porous composite particles

[0062] The preparation process of the porous composite particle material in Comparative Example 5 (1) is the same as that in Example 1.

[0063] (2) Raw material preparation: Take 30 parts of dolomite, 10 parts of tourmaline, 50 parts of sodium zeolite, and 10 parts of anhydrous sodium carbonate.

[0064] (3) The porous composite particles prepared in this comparative example can be directly used for the mineralization treatment of low-mineral drinking water or pure water. After treating pure water with a feed amount of 20 mg / mL for 15 min, the pH of the treated pure water stabilized between 7.5 and 9, where Ca:Na:Mg:K was approximately 7:7:4:1.

[0065] Table 8. Comparative Example 5: Effluent water quality range of porous composite particles

[0066] The preparation process of the porous composite particle material in Comparative Example 6 (1) is the same as that in Example 1. However, the firing temperature was changed to 500℃.

[0067] (2) Raw material preparation: Take 30 parts of dolomite, 10 parts of tourmaline, 50 parts of sodium zeolite, and 10 parts of anhydrous sodium carbonate.

[0068] (3) The porous composite particles prepared in this comparative example cannot be fired and disintegrated after contact with moisture.

[0069] (I) Taste Evaluation The method and objective for preparing composite mineralized particles proposed in this invention are based on the following: In order to clarify the specific proportions of each element in water with better taste, four reagents, sodium chloride, potassium chloride, calcium chloride and magnesium chloride, were used to prepare water samples with medium and low mineralization levels (50~250 mg / L) according to the following proportions: potassium:sodium:calcium:magnesium = 16:7:4:4; calcium:sodium:magnesium:potassium = 36:16:9:4; calcium:sodium:magnesium:potassium = 27:27:9:4; calcium:sodium:magnesium:potassium = 24:24:16:4 (referred to as groups A, B, C and D respectively). Sensory experiments and electronic tongue evaluation were conducted.

[0070] As can be seen from the radar diagram, differences in ion ratio and content significantly affect the taste characteristics of drinking water (Figure 1). Sensory evaluation results show that when TDS is below 100 mg / L, all water samples taste better than pure water, with K... + or Ca 2+ When the proportion of Na is relatively high, the water samples are ranked similarly, but appropriately increasing Na... + or Mg 2+ The water sample with the higher proportion of sodium ions ranked better, and maintained a good taste even after TDS exceeded 100 mg / L (Figure 2). This may be related to the fact that the salty and astringent taste characteristics of sodium ions increase more slowly with increasing concentration compared to calcium and magnesium ions. Therefore, it can be seen that when the proportion of calcium and sodium leaching is higher than that of magnesium and potassium, the taste of drinking water can be guaranteed over a wider range of TDS variations while effectively reducing the risk of scaling. Therefore, in the design of mineral leaching elements in this material, it is best to have a higher proportion of calcium and sodium leaching than that of magnesium and potassium, close to calcium:sodium:magnesium:potassium = 27:27:9:4.

[0071] (II) Key Indicators of Taste of Water from Examples 1-3 and Comparative Examples 1-5 Table 9 Key Factors Affecting Taste

[0072] Unit: mg / L. As shown in Table 9, compared to pure water, the pH of the effluent from each embodiment ranged from 7.92 to 8.42, and the levels of calcium, sodium, magnesium, and potassium were significantly increased. The dissolved ions were mainly calcium and sodium, which is related to the presence of calcium silicate and sodium aluminum silicate phases in the material (Figure 3, left). This indicates that the composite mineralizing particles proposed in this invention can regulate the mineral content in pure water, increase the content of key cations that affect the taste of drinking water, and control them within a certain range. 2+ 4.59~9.06 mg / L, Na + 3.99~6.67 mg / L, Mg 2+ 1.26~3.72 mg / L, K + 0.30~0.68 mg / L. This basically meets the design objective of (I) where the ratio of calcium and sodium leaching is higher than that of magnesium and potassium, and is close to the optimal ratio of calcium:sodium:magnesium:potassium = 27:27:9:4. At the same time, the Ca, Na, Mg and K elements on the material surface are also close to this ratio (Figure 4 right), which corresponds to each other.

[0073] Furthermore, the effluent from Comparative Examples 1 and 2 can also adjust the mineral content of pure water, but the pH is closer to the limit of 8.5. Among them, Comparative Example 2 exceeds the standard limit and does not meet the drinking standard.

[0074] Furthermore, the effluent from Comparative Examples 3 and 4 also showed adjustable mineral content in pure water, but the pH exceeded the standard limit and did not meet drinking standards. In addition, the TDS of Comparative Examples 3 and 4 fluctuated significantly, which may be related to the lack of tourmaline as structural support in the particles or insufficient firing temperature due to a lack of sodium carbonate.

[0075] Furthermore, the effluent from Comparative Example 5 also showed adjustable mineral content in pure water, with a pH close to the 8.5 limit, meeting the standard. However, the TDS of Comparative Example 5 also fluctuated significantly, which may be related to the decomposition of uncalcined dolomite during the particle firing process, producing carbon dioxide.

[0076] Furthermore, comparative ratios 3, 4, and 5 showed a higher proportion of dissolved magnesium ions in the effluent, and the ratio of dissolved ions did not meet the requirements for a good taste. In addition, the high proportion of calcium and magnesium ions posed a high risk of scaling and did not meet the target requirements.

[0077] Furthermore, as shown in Figure 5, the porous composite particles of Example 2, after experiencing initial dissolution decay during 50 cycles, maintained a stable TDS level of 20-30 mg / L, while ion dissolution remained consistently stable. (Ca...) 2+5.56~8.79 mg / L, Na + 5.97~7.58 mg / L, Mg 2+ 0.99~2.4 mg / L, K + The concentrations ranged from 0.36 to 0.67 mg / L, and the XRD patterns showed no significant decrease before and after dissolution (Figure 3, right), indicating that the material exhibits excellent dissolution stability and ion regulation capabilities. This is related to the material's mesoporous structure (Figure 4, left).

[0078] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A slow-release mineralized porous composite particle, characterized in that, It includes the following components: 10-40 parts of calcined dolomite, 5-20 parts of tourmaline, 30-70 parts of zeolite, and 5-20 parts of flux.

2. The slow-release mineralized porous composite particles according to claim 1, characterized in that, The slow-release mineralized porous composite particles comprise the following components: 15-40 parts of calcined dolomite, 5-15 parts of tourmaline, 40-70 parts of zeolite, and 5-15 parts of flux.

3. The slow-release mineralized porous composite particles according to claim 1 or 2, characterized in that, The calcined dolomite was prepared by calcining dolomite powder at 600-800℃ for 1-3 hours.

4. The slow-release mineralized porous composite particles according to claim 1 or 2, characterized in that, The zeolite is at least one of sodium-type zeolite, potassium-type zeolite, or calcium-sodium mixed zeolite; the flux is anhydrous sodium carbonate.

5. The slow-release mineralized porous composite particles according to claim 1 or 2, characterized in that, The pore volume of the slow-release mineralized porous composite particles is 0.02~0.06 cm³. 3 / g, specific surface area is 5~15m² 2 / g; The slow-release mineralized particles are obtained by mixing dolomite calcination, tourmaline, zeolite and flux in a certain proportion, sieving, pressing and sintering.

6. A method for preparing the sustained-release mineralized porous composite particles according to any one of claims 1 to 5, characterized in that, Includes the following steps: (1) Lightly calcining dolomite powder to obtain dolomite calcined material; (2) After pretreatment, tourmaline and zeolite are ground and mixed evenly with dolomite calcined material and flux in proportion and then sieved to obtain a mixture; (3) Pressing the mixture to obtain a preform, then drying and sintering the obtained preform, then naturally cooling, rinsing and drying to obtain slow-release mineralized porous composite particles.

7. The method for preparing sustained-release mineralized porous composite particles according to claim 6, characterized in that, The light calcination in step (1) is as follows: Under an air atmosphere, the dolomite powder is heated to 600-800℃ at a rate of 1-10℃ / min and held for 1-3 hours, then cooled to 100-200℃ at a rate of 1-10℃ / min, and finally cooled naturally to room temperature.

8. The method for preparing sustained-release mineralized porous composite particles according to claim 6, characterized in that, The pretreatment in step (2) is as follows: place tourmaline or zeolite in water and stir at 100-400 r / min for 6-12 hours, changing the water 2-3 times during the period, until the difference in conductivity of the upper clear liquid is no more than 5 µs / cm, then filter by suction, dry the resulting filter cake, grind and sieve it for later use.

9. The method for preparing sustained-release mineralized porous composite particles according to claim 6, characterized in that, The pressing pressure in step (3) is 1~8kN and the holding time is 1~5min; the sintering in step (3) is as follows: under air atmosphere, the dried preform is heated to 650~1000℃ at a rate of 1~10℃ / min, held for 1~3h, then cooled to 100~200℃ at a rate of 1~10℃ / min, and finally cooled to room temperature naturally; the rinsing and drying in step (3) is as follows: rinsing with a flow rate of 100~300mL / min for 10~16h, and drying at 60~80℃ after rinsing.

10. The use of the slow-release mineralized porous composite particles according to any one of claims 1 to 5 in drinking water mineralization treatment and / or drinking water taste improvement.

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