Multiple processing and impurity removing process for shell powder

Abstract

The invention relates to the technical field of fine processing of shells, in particular to a multi-shell powder processing and impurity removing process which comprises the following steps: firstly, cleaning oyster shells twice with clear water, cutting the oyster shells into particles, soaking the particles with alkaline water, screening, and performing ozone oxidation to obtain refined shell particles A; then carrying out pelletizing, alkali soaking and ozone oxidation again to obtain refined shell particles B; and finally, carrying out wet grinding twice, calcining at high temperature and carrying out ultraviolet sterilization to obtain the shell powder. Secondary pelletizing, alkali soaking and ozone oxidation can enable the shells to be subjected to a finer physical and chemical separation process, so that impurities in the shell powder are more effectively removed; the ozone oxidation utilizes the strong oxidizing property of ozone to decompose dichlorodiphenyl trichloroethane, so that organochlorine pesticide residues such as dichlorodiphenyl trichloroethane in the shells are removed; the uniformity of the shell powder can be improved through two times of wet grinding, active ingredients in the shell powder can be better released, and the using effect is improved. The prepared shell powder is high in purity and has a wide application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of shell fine processing, and in particular to a multiple shell powder processing and impurity removal process. Background Art

[0002] Shells are also called mollusk mantles. Most of them are calcium carbonate, which accounts for 95% of the overall structure of shells. They also contain some biomass - chitin, which mainly includes insoluble polysaccharide chitin, insoluble protein and soluble protein. There are many inorganic salts composed of trace elements in shells, such as K, Na, Mg, Fe, Zn, Cu, Al, Se, P and other elements. Shells can generally be divided into three layers. The outermost layer is the dark brown cuticle (shell skin), which is thin and transparent. It has the function of preventing carbonic acid erosion and is composed of chitin secreted by the edge of the mantle; the middle layer is the prismatic layer (shell layer), which is thicker and composed of prismatic calcite secreted by the edge of the mantle. The outer and middle layers can expand the area of ​​the shell but do not increase the thickness; the inner layer is the pearl layer (bottom layer), which is composed of leaf-shaped aragonite (aragonite) secreted by the entire surface of the mantle. It has a beautiful luster and can be thickened as the body grows.

[0003] Shell powder is a powder made by crushing the shells of oysters, clams, clams, snails, etc. after the flesh is removed. It is a mineral supplement and can be used as a high-end material for food, cosmetics and interior decoration. It is used in livestock and poultry feed, food calcium source additives, jewelry processing, desiccant, etc.

[0004] In the prior art, shell powder is often processed and impurities are removed. For example, patent technology document CN115251379A discloses a shell powder processing method, which is completed by the following steps: taking shell raw materials, soaking them in 50-60℃ hot water for at least 30 minutes, then washing and impurities removal, and then spraying with clean water and drying with hot air to obtain clean materials; putting the materials into a baking machine, and the materials are successively subjected to 200℃, 300℃, 500℃, and 750-800℃ temperature sections, and the whole process is air-rotating baking, and then the materials are discharged and cooled; the materials are crushed and ground by a pulverizer, and powder with a particle size of more than 120 mesh is screened out to make shell powder products. This invention has low production cost and no pollution to the environment, but some impurities in the shell powder cannot be completely removed, and the product purity is not high.

[0005] Therefore, according to the above-mentioned related technologies, it is urgent to develop a high-purity multiple shell powder processing and impurity removal process. Summary of the invention

[0006] In view of this, the purpose of the present invention is to propose a multiple shell powder processing and impurity removal process to solve the problem of low purity in the shell powder processing and impurity removal process in the prior art.

[0007] Based on the above purpose, the present invention provides a multiple shell powder processing and impurity removal process.

[0008] A multiple shell powder processing and impurity removal process comprises the following steps:

[0009] Step S1. Take the oyster shell raw material, put it into a pool, soak it in 50-60℃ hot water for 0.5-2h, rinse it with clean water, then put it into a pelletizer, cut it into particles, and then sieve it with a filter to obtain crude shell particles A;

[0010] Step S2. The crude shell particles A are placed in a container containing sodium carbonate, and placed in a magnetic stirrer for heating and stirring, sieved and washed with clean water, and then placed in a closed container for ozone oxidation to obtain refined shell particles A;

[0011] Step S3. After the refined shell particles A are diced and sieved again, they are mixed with sodium carbonate and heated and stirred in a magnetic stirrer, and then washed and oxidized with ozone to obtain refined shell particles B;

[0012] Step S4. Using water as a grinding aid, the refined shell particles B and water are mixed in a ratio of 1 g: 4-5 mL to prepare a grinding mother liquor, which is added to a ball mill, and then placed in a wet grinder for primary grinding. After screening, the fine powder is subjected to secondary grinding, and larger particles and insufficiently ground materials are ground again, and finally dried to obtain a crude shell powder;

[0013] Step S5. placing the crude shell powder into a calcining furnace and calcining at high temperature to obtain refined shell powder;

[0014] Step S6. Put the refined shell powder into an ultraviolet disinfection cabinet to obtain shell powder.

[0015] Preferably, the pelletizer in step S1 is a roller cutter pelletizer, the cutter shaft speed is 800-1000 r / min, and the pelletizing time is 5-10 min.

[0016] Preferably, the filter screen in step S1 is 6-8 mesh, and the particle size of the crude shell particles A is 3-4 cm.

[0017] Preferably, the rotation speed of the magnetic stirrer in step S2 is 180-220 r / min, the temperature during the heating and stirring is 55-65° C., the heating time is 30-40 min, and a 6-8 mesh filter is used for the screening.

[0018] Preferably, the ozone oxidation time in step S2 is 40-60 min, and the concentration of the ozone aqueous solution is 1.3-1.8 mg / L, which can remove organochlorine pesticide residues such as DDT in shell particles and kill bacteria and viruses on the shell surface.

[0019] Preferably, the pelletizer in step S3 is a roller-type pelletizer, the blade shaft speed is 1200-1500r / min, the pelletizing time is 8-13min, the screening after pelletizing uses a 18-30 mesh filter, the speed of the magnetic stirrer is 180-220r / min, the temperature during heating and stirring is 55-65°C, and the heating time is 20-30min.

[0020] Preferably, in step S3, the ozone oxidation time is 20-30 min, the concentration of the ozone aqueous solution is 1.3-1.8 mg / L, and the particle size of the refined shell particles B is 0.5-1 cm.

[0021] Preferably, in step S4, the diameter of the grinding balls for the primary grinding is 2-3 mm, the grinding speed is 500-600 r / min, and the grinding time is 20-40 min. The screening uses a 230-270 mesh filter. The diameter of the grinding balls for the secondary grinding is 0.2-0.5 mm, the grinding speed is 500-600 r / min, and the grinding time is 5-15 min. The particle size of the crude shell powder is 25-40 μm, the drying temperature is 98-103 ° C, and the drying time is 20-30 min.

[0022] Preferably, the high temperature calcination in step S5 is carried out at a temperature of 900-1000° C. for 3-4 hours, and the organic residues are converted into water vapor and carbon dioxide, thereby being removed from the shell powder.

[0023] Preferably, the operating temperature of the ultraviolet disinfection cabinet in step S6 is 70-80°C, and the irradiation time is 5-8 minutes, which kills the bacteria in the shell powder.

[0024] Beneficial effects of the present invention:

[0025] The invention provides a multiple shell powder processing and impurity removal process. The invention firstly washes oyster shells with clean water twice, cuts them into particles and soaks them with alkaline water, sieves them and oxidizes them with ozone to obtain refined shell particles A; then, the particles are cut again, soaked in alkaline and oxidized with ozone to obtain refined shell particles B; then, the wet grinding method is used for primary grinding and re-grinding, and finally, the shell powder is obtained by high-temperature calcination and ultraviolet sterilization.

[0026] The secondary granulation, alkaline bubbling and ozone oxidation in the present invention will make the shells undergo a more detailed physical and chemical separation process, more effectively remove impurities in the shell powder and help obtain more uniform particles for subsequent processing; wherein, ozone oxidation utilizes the strong oxidizing property of ozone to decompose DDT through direct oxidation and indirect oxidation, thereby removing the DDT and other difficult-to-degrade organochlorine pesticide residues in the shells; primary grinding and regrinding are used during wet grinding to improve the uniformity of the shell powder, better release the active ingredients in the shell powder, and improve the use effect. The shell powder prepared by the present invention has high purity and has a wide application prospect compared with the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 The present invention is a process flow chart of the shell powder processing and impurity removal process. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0030] The sources and properties of some of the raw materials used in the present invention are as follows:

[0031] Sodium carbonate was purchased from Henan Kaijie Water Treatment Co., Ltd.

[0032] Embodiment 1: A multiple shell powder processing and impurity removal process:

[0033] S1. Take the oyster shell raw material, put it into a pool, soak it in 50℃ hot water for 2h, rinse it with clean water, and then put it into a roller cutter with a speed of 800r / min, cut it into particles for 10min, and then sieve it with a 6-mesh filter to obtain a crude shell particle A with a particle size of 4cm;

[0034] S2. The crude shell particles A were placed in a container containing sodium carbonate, and heated and stirred in a magnetic stirrer at a speed of 180 r / min for 30 min at a temperature of 65°C, and then sieved with a 6-mesh filter and washed with clean water, and then placed in a closed container for ozone oxidation for 40 min. The concentration of the ozone aqueous solution was 1.8 mg / L to obtain refined shell particles A;

[0035] S3. The refined shell particles A were again placed in a roller cutter at a speed of 1200 r / min, cut into particles for 13 min, and then sieved with a 18-mesh filter. After mixing with sodium carbonate, they were heated and stirred in a magnetic stirrer at a speed of 180 r / min for 20 min at a temperature of 65°C. After washing with clean water, they were placed in a closed container for ozone oxidation for 20 min. The concentration of the ozone aqueous solution was 1.8 mg / L to obtain refined shell particles B with a particle size of 1 cm;

[0036] S4. Using water as a grinding aid, the refined shell particles B and water were mixed in a ratio of 1g:4mL to prepare a grinding mother liquor, which was added to a ball mill, and then placed in a wet grinder for primary grinding. The grinding ball diameter was 3mm, the grinding speed was 500r / min, and the grinding time was 20min. After screening with a 230-mesh filter, the fine powder was subjected to secondary grinding. The grinding ball diameter of the secondary grinding was 0.5mm, the grinding speed was 500r / min, and the grinding time was 5min. Larger particles and insufficiently ground materials were ground again, and finally dried at 98°C for 30min to obtain a crude shell powder;

[0037] Step S5. placing the crude shell powder into a calcining furnace and calcining at 900° C. for 4 h to obtain refined shell powder;

[0038] Step S6. Place the refined shell powder in a 70°C ultraviolet disinfection cabinet for disinfection for 8 minutes to obtain shell powder.

[0039] Embodiment 2: A multiple shell powder processing and impurity removal process:

[0040] S1. Take the oyster shell raw material, put it into a pool, soak it in 50°C hot water for 1.5 hours, rinse it with clean water, and then put it into a roller cutter with a speed of 850r / min, cut it into particles for 9 minutes, and then sieve it with a 6-mesh filter to obtain a crude shell particle A with a particle size of 4cm;

[0041] S2. The crude shell particles A were placed in a container containing sodium carbonate, and heated and stirred in a magnetic stirrer at a speed of 190 r / min for 30 min at a temperature of 65°C, then sieved with a 6-mesh filter and washed with clean water, and then placed in a closed container for ozone oxidation for 45 min. The concentration of the ozone aqueous solution was 1.7 mg / L to obtain refined shell particles A;

[0042] S3. The refined shell particles A were again placed in a roller cutter at a speed of 1300 r / min, cut into particles for 12 min, and then sieved with a 20-mesh filter. After mixing with sodium carbonate, they were heated and stirred in a magnetic stirrer at a speed of 190 r / min for 20 min at a temperature of 65°C. After washing with clean water, they were placed in a closed container for ozone oxidation for 20 min. The concentration of the ozone aqueous solution was 1.7 mg / L, and refined shell particles B with a particle size of 0.9 cm were obtained;

[0043] S4. Using water as a grinding aid, the refined shell particles B and water were mixed in a ratio of 1g:4mL to prepare a grinding mother liquor, which was added to a ball mill, and then placed in a wet grinder for primary grinding. The grinding ball diameter was 3mm, the grinding speed was 500r / min, and the grinding time was 25min. After screening with a 240-mesh filter, the fine powder was subjected to secondary grinding. The grinding ball diameter of the secondary grinding was 0.4mm, the grinding speed was 500r / min, and the grinding time was 10min. Larger particles and insufficiently ground materials were ground again, and finally dried at 99°C for 25min to obtain a crude shell powder.

[0044] Step S5. placing the crude shell powder into a calcining furnace and calcining at 900° C. for 4 h to obtain refined shell powder;

[0045] Step S6. Place the refined shell powder in a 70°C ultraviolet disinfection cabinet for disinfection for 7 minutes to obtain shell powder.

[0046] Embodiment 3: A multiple shell powder processing and impurity removal process:

[0047] S1. Take the oyster shell raw material, put it into a pool, soak it in 55°C hot water for 1.5 hours, rinse it with clean water, and then put it into a roller cutter at a speed of 900r / min, cut it into particles for 8 minutes, and then sieve it with a 7-mesh filter to obtain a crude shell particle A with a particle size of 4cm;

[0048] S2. The crude shell particles A were placed in a container containing sodium carbonate and heated and stirred in a magnetic stirrer at a speed of 200 r / min for 35 min at a temperature of 60°C, then sieved with a 7-mesh filter and washed with clean water, and then placed in a closed container for ozone oxidation for 50 min. The concentration of the ozone aqueous solution was 1.6 mg / L to obtain refined shell particles A;

[0049] S3. The refined shell particles A were again placed in a roller cutter at a speed of 1300 r / min, cut into particles for 11 min, and then sieved with a 24-mesh filter. After mixing with sodium carbonate, they were heated and stirred in a magnetic stirrer at a speed of 200 r / min for 25 min at a temperature of 60°C. After washing with clean water, they were placed in a closed container for ozone oxidation for 25 min. The concentration of the ozone aqueous solution was 1.6 mg / L, and refined shell particles B with a particle size of 0.8 cm were obtained.

[0050] S4. Using water as a grinding aid, the refined shell particles B and water were mixed in a ratio of 1g:4mL to prepare a grinding mother liquor, which was added to a ball mill, and then placed in a wet grinder for primary grinding. The grinding ball diameter was 3mm, the grinding speed was 550r / min, and the grinding time was 30min. After screening with a 250-mesh filter, the fine powder was subjected to secondary grinding. The grinding ball diameter of the secondary grinding was 0.3mm, the grinding speed was 550r / min, and the grinding time was 10min. Larger particles and insufficiently ground materials were ground again, and finally dried at 100°C for 25min to obtain a crude shell powder.

[0051] Step S5. placing the crude shell powder into a calcining furnace and calcining at 950° C. for 3.5 h to obtain refined shell powder;

[0052] Step S6. Place the refined shell powder in a 75°C ultraviolet disinfection cabinet for disinfection for 7 minutes to obtain shell powder.

[0053] Embodiment 4: A multiple shell powder processing and impurity removal process:

[0054] S1. Take the oyster shell raw material, put it into a pool, soak it in 55°C hot water for 1 hour, rinse it with clean water, and then put it into a roller cutter with a speed of 950r / min, cut it into particles for 7 minutes, and then sieve it with a 7-mesh filter to obtain a crude shell particle A with a particle size of 3cm;

[0055] S2. The crude shell particles A were placed in a container containing sodium carbonate, and heated and stirred in a magnetic stirrer at a speed of 210 r / min for 35 min at a temperature of 60°C, and then sieved with a 7-mesh filter and washed with clean water, and then placed in a closed container for ozone oxidation for 55 min. The concentration of the ozone aqueous solution was 1.5 mg / L to obtain refined shell particles A;

[0056] S3. The refined shell particles A were again placed in a roller cutter at a speed of 1400 r / min, cut into particles for 10 min, and then sieved with a 28-mesh filter. After mixing with sodium carbonate, they were heated and stirred in a magnetic stirrer at a speed of 210 r / min for 25 min at a temperature of 60°C. After washing with clean water, they were placed in a closed container for ozone oxidation for 25 min. The concentration of the ozone aqueous solution was 1.5 mg / L to obtain refined shell particles B with a particle size of 0.7 cm;

[0057] S4. Take water as a grinding aid, prepare the grinding mother liquid of refined shell particles B and water in the amount ratio of 1g:5mL, add it to the ball mill, put it into the wet grinder for primary grinding, the grinding ball diameter is 2mm, the grinding speed is 550r / min, and the grinding time is 35min. After screening with a 250-mesh filter, the fine powder is secondary ground, the grinding ball diameter of the secondary grinding is 0.3mm, the grinding speed is 550r / min, and the grinding time is 15min. Larger particles and insufficiently ground materials are ground again, and finally dried at 102°C for 20min to obtain crude shell powder;

[0058] Step S5. placing the crude shell powder into a calcining furnace and calcining at 950° C. for 3.5 h to obtain refined shell powder;

[0059] Step S6. Place the refined shell powder in a 75°C ultraviolet disinfection cabinet for disinfection for 6 minutes to obtain shell powder.

[0060] Embodiment 5: A multiple shell powder processing and impurity removal process:

[0061] S1. Take the oyster shell raw material, put it into a pool, soak it in 60℃ hot water for 0.5h, rinse it with clean water, and then put it into a roller cutter with a speed of 1000r / min, cut it into particles for 5min, and then sieve it with an 8-mesh filter to obtain a crude shell particle A with a particle size of 3cm;

[0062] S2. The crude shell particles A were placed in a container containing sodium carbonate, and heated and stirred in a magnetic stirrer at a speed of 220 r / min for 40 min at a temperature of 55°C, and then sieved with an 8-mesh filter and washed with clean water, and then placed in a closed container for ozone oxidation for 60 min. The concentration of the ozone aqueous solution was 1.3 mg / L to obtain refined shell particles A;

[0063] S3. The refined shell particles A were again placed in a roller cutter at a speed of 1500 r / min, cut into particles for 8 min, and then sieved with a 30-mesh filter. After mixing with sodium carbonate, they were heated and stirred in a magnetic stirrer at a speed of 220 r / min for 30 min at a temperature of 55°C. After washing with clean water, they were placed in a closed container for ozone oxidation for 30 min. The concentration of the ozone aqueous solution was 1.3 mg / L to obtain refined shell particles B with a particle size of 0.5 cm;

[0064] S4. Using water as a grinding aid, the refined shell particles B and water were mixed in a grinding mother liquor in a ratio of 1g:5mL and added to a ball mill, and then placed in a wet grinder for primary grinding. The grinding ball diameter was 2mm, the grinding speed was 600r / min, and the grinding time was 40min. After screening with a 270-mesh filter, the fine powder was subjected to secondary grinding. The grinding ball diameter of the secondary grinding was 0.2mm, the grinding speed was 600r / min, and the grinding time was 15min. The larger particles and the insufficiently ground materials were ground again, and finally dried at 103°C for 20min to obtain a crude shell powder;

[0065] Step S5. placing the crude shell powder into a calcining furnace and calcining at 1000° C. for 3 h to obtain refined shell powder;

[0066] Step S6. Put the refined shell powder into an 80°C ultraviolet disinfection cabinet for disinfection for 5 minutes to obtain shell powder.

[0067] Comparative Example 1:

[0068] Compared with Example 1, this comparative example does not perform ozone oxidation during the processing and impurity removal of multiple shell powder. The remaining steps and parameters are the same and will not be repeated in this comparative example. Shell powder is finally obtained.

[0069] Comparative Example 2:

[0070] S1. Take the oyster shell raw material, put it into a pool, soak it in 50℃ hot water for 2h, rinse it with clean water, and then put it into a roller cutter with a speed of 1200r / min, cut it into particles for 13min, and then sieve it with a 18-mesh filter to obtain crude shell particles with a particle size of 1cm;

[0071] S2. The crude shell particles A were placed in a container containing sodium carbonate and heated and stirred in a magnetic stirrer at a speed of 180 r / min for 30 min at a temperature of 65°C, then sieved with a 6-mesh filter and washed with clean water, and then placed in a closed container for ozone oxidation for 40 min. The concentration of the ozone aqueous solution was 1.8 mg / L to obtain refined shell particles;

[0072] S3. Take water as a grinding aid, prepare the grinding mother liquid of refined shell particles B and water in a dosage ratio of 1g:4mL, add it to a ball mill, put it into a wet grinder for primary grinding, the grinding ball diameter is 3mm, the grinding speed is 500r / min, and the grinding time is 20min. After screening with a 230-mesh filter, the fine powder is subjected to secondary grinding. The grinding ball diameter of the secondary grinding is 0.5mm, the grinding speed is 500r / min, and the grinding time is 5min. Larger particles and insufficiently ground materials are ground again, and finally dried at 98°C for 30min to obtain crude shell powder;

[0073] Step S4. placing the crude shell powder into a calcining furnace and calcining at 900° C. for 4 h to obtain refined shell powder;

[0074] Step S5. Put the refined shell powder into a 70°C ultraviolet disinfection cabinet for disinfection for 8 minutes to obtain shell powder.

[0075] Comparative Example 3:

[0076] Compared with Example 1, this comparative example only adjusts "the concentration of the ozone aqueous solution is 1.8 mg / L" to "the concentration of the ozone aqueous solution is 0.8 mg / L", and the remaining steps and parameters are the same and will not be repeated in this comparative example, and finally shell powder is obtained.

[0077] Comparative Example 4:

[0078] Compared with Example 1, this comparative example only adjusts "the concentration of the ozone aqueous solution is 1.8 mg / L" to "the concentration of the ozone aqueous solution is 4 mg / L", and the remaining steps and parameters are the same and will not be repeated in this comparative example, and finally shell powder is obtained.

[0079] Comparative Example 5:

[0080] Compared with Example 1, this comparative example does not perform secondary ball milling during the processing and impurity removal of multiple shell powders. The remaining steps and parameters are the same and will not be repeated in this comparative example. Shell powder is finally obtained.

[0081] Performance Test:

[0082] purity:

[0083] Accurately weigh 2.8g EDTA and prepare a 0.02mol / L EDTD standard solution. Then accurately weigh 5g of the shell powder prepared in Example 1-Example 5 and Comparative Example 1-Comparative Example 5 respectively and place them in an aqueous solution. Add 20mL of 6mol / L hydrochloric acid solution and heat at 70-80°C to prepare the test solutions of Example 1-Example 5 and Comparative Example 1-Comparative Example 5. Accurately pipette 25.00mL of the test solution into a 250mL conical flask, use pH test paper to roughly measure the pH of the solution to be acidic (pH test paper is red), add 5.00mL triethanolamine solution, then add 5mL1mol / LNaOH solution, adjust pH=12-13, and then add 10mg calcium-carboxylic acid indicator. Titrate with EDTA standard solution until the color of the test solution changes from light red to light blue, which is the titration end point. Record the volume V of EDTA consumed, calculate the mass fraction of calcium in the shell powder, which is the purity of the shell powder;

[0084] Purity calculation formula:

[0085] Purity (%) = (c EDTA V EDTA M CaO / m贝壳粉 )×100%

[0086] Yield:

[0087] Weigh the masses of the oyster shell raw materials used in Examples 1 to 5 and Comparative Examples 1 to 5 and the masses of the shell powders prepared in Examples 1 to 5 and Comparative Examples 1 to 5 respectively;

[0088] Yield calculation formula:

[0089] Yield = (mass of shell powder / mass of oyster shell) × 100%

[0090] Antibacterial properties:

[0091] Pour 15mL PDA culture medium melted and cooled to about 50°C into a sterilized culture dish. After solidification, use a pipette to transfer 100μl of single spore suspension, and use a sterilized coating rod to evenly apply it on the solidified PDA culture medium plate to make a bacterial plate. Then use a hole puncher to punch the ordinary qualitative filter paper into a round paper with a diameter of 6mm and place it in a dry and clean culture dish, sterilize it with high pressure steam, sterilize it at 121°C for 20min, and then dry it in an oven. Weigh 1g of the shell powder prepared in Examples 1-5 and Comparative Examples 1-5 respectively and pour it in the center of each plate. Pour one portion of oyster shell powder on one plate, try to make the stacked oyster shell powder into a circle with a diameter of 20mm, and mark it on the bottom of the dish, and then place it in a 28°C biochemical incubator for culture. Observe the results after 72h and measure the diameter of the inhibition zone.

[0092] Table 1 Summary of experimental data in Examples 1 to 5 and Comparative Examples 1 to 5

[0093]

[0094]

[0095] Data Analysis:

[0096] As can be seen from Table 1, the shell powder prepared in Examples 1 to 5 of the present invention has higher purity and stronger antibacterial properties. This may be because the present invention uses secondary granulation, alkaline bubbling, and ozone oxidation to make the shell undergo a more detailed physical and chemical separation process, more effectively remove impurities in the shell powder and help obtain more uniform particles for subsequent processing, thereby improving the purity of the shell powder; and ozone oxidation utilizes the strong oxidizing property of ozone to decompose DDT through direct oxidation and indirect oxidation, thereby removing DDT and other difficult-to-degrade organochlorine pesticide residues in the shell, further contributing to the improvement of product purity; primary grinding and re-grinding during wet grinding can improve the uniformity of the shell powder, better release the active ingredients in the shell powder, and improve the antibacterial effect.

[0097] In Comparative Example 1, since ozone oxidation was not performed during the processing and impurity removal of multiple shell powders, it can be seen from Table 1 that the purity of the shell powder prepared by this method is relatively low. This may be because ozone oxidation can effectively remove organochlorine pesticide residues such as DDT in shell powder. The lack of this treatment step may result in a large amount of organic impurities remaining in the shell powder, thereby affecting the purity of the product. Therefore, the purity of Comparative Example 1 is worse than that of Example 1; in Comparative Example 2, since secondary granulation, alkaline immersion, and ozone oxidation were not performed, it can be seen from Table 1 that the purity of the shell powder prepared by this method is relatively low. This may be because these treatment steps can adjust the particle size distribution and surface properties of the shell powder and can better remove impurities in the product. Therefore, the purity of Comparative Example 1 is worse than that of Example 1; in Comparative Example 3, since "the concentration of the ozone aqueous solution is 1.8 mg / L" is adjusted to "the concentration of the ozone aqueous solution is 0.8 mg / L", it can be seen from Table 1 that the purity of the shell powder prepared by this method is relatively low. This may be because insufficient ozone concentration will lead to low oxidation efficiency, and the expected treatment effect cannot be achieved, which may not be sufficient to effectively degrade DDT. Therefore, Comparative Example 1 The purity is worse than that of Example 1; in Comparative Example 4, since the "concentration of the ozone aqueous solution is 1.8 mg / L" is adjusted to "the concentration of the ozone aqueous solution is 4 mg / L", it can be seen from Table 1 that the shell powder prepared by this method has low purity and poor antibacterial effect. This may be due to the fact that the ozone concentration is too high, which may lead to excessive oxidation, which will not only destroy the structure of the shell powder itself and affect the performance of the shell powder, but also may produce toxic ozonation by-products and increase impurities. Therefore, the purity and antibacterial effect of Comparative Example 1 are worse than those of Example 1; in Comparative Example 5, since the secondary ball milling was not performed during the processing and impurity removal of multiple shell powders, it can be seen from Table 1 that the shell powder prepared by this method has low purity and poor antibacterial effect. This may be due to the fact that unnecessary impurities may be mixed in the powder. The secondary ball milling can remove these impurities and improve the uniformity of the powder, improve the microstructure of the powder, such as reducing agglomerated particles and increasing the reactivity of the powder, and the defects that may be generated in the initial ball milling, such as cracks, holes, etc., can be repaired or reduced by the secondary ball milling to improve the product quality. Therefore, the purity and antibacterial effect of Comparative Example 1 are worse than those of Example 1.

[0098] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0099] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A multiple shell powder processing and impurity removal process, characterized in that: The following steps are involved: Step S1. Take the oyster shell raw material, put it into a pool, soak it in 50-60℃ hot water for 0.5-2h, rinse it with clean water, then put it into a pelletizer, cut it into particles, and then sieve it with a filter to obtain crude shell particles A; Step S2. The crude shell particles A are placed in a container containing sodium carbonate, and placed in a magnetic stirrer for heating and stirring, sieved and washed with clean water, and then placed in a closed container for ozone oxidation to obtain refined shell particles A; Step S3. After the refined shell particles A are diced and sieved again, they are mixed with sodium carbonate and heated and stirred in a magnetic stirrer, and then washed and oxidized with ozone to obtain refined shell particles B; Step S4. Using water as a grinding aid, the refined shell particles B and water are mixed in a ratio of 1 g: 4-5 mL to prepare a grinding mother liquor, which is added to a ball mill, and then placed in a wet grinder for primary grinding. After screening, the fine powder is subjected to secondary grinding, and larger particles and insufficiently ground materials are ground again, and finally dried to obtain a crude shell powder; Step S5. placing the crude shell powder into a calcining furnace and calcining at high temperature to obtain refined shell powder; Step S6. Put the refined shell powder into an ultraviolet disinfection cabinet to obtain shell powder.

2. The multiple shell powder processing and impurity removal process according to claim 1, characterized in that: The pelletizer in step S1 is a roller cutter pelletizer, the blade shaft speed is 800-1000 r / min, and the pelletizing time is 5-10 min.

3. The multiple shell powder processing and impurity removal process according to claim 1, characterized in that: The filter screen in step S1 is 6-8 mesh, and the particle size of the crude shell particles A is 3-4 cm.

4. The multiple shell powder processing and impurity removal process according to claim 1, characterized in that: The speed of the magnetic stirrer in step S2 is 180-220 r / min, the temperature during the heating and stirring is 55-65° C., the heating time is 30-40 min, and a 6-8 mesh filter is used for the screening.

5. The multiple shell powder processing and impurity removal process according to claim 1 is characterized in that: The ozone oxidation time in step S2 is 40-60 minutes, and the concentration of the ozone aqueous solution is 1.3-1.8 mg / L.

6. The multiple shell powder processing and impurity removal process according to claim 1 is characterized in that: The pelletizer in step S3 is a roller-type pelletizer, the blade shaft speed is 1200-1500r / min, the pelletizing time is 8-13min, the screening after pelletizing uses a 18-30 mesh filter, the speed of the magnetic stirrer is 180-220r / min, the temperature during heating and stirring is 55-65°C, and the heating time is 20-30min.

7. The multiple shell powder processing and impurity removal process according to claim 1 is characterized in that: In step S3, the ozone oxidation time is 20-30 min, the concentration of the ozone aqueous solution is 1.3-1.8 mg / L, and the particle size of the refined shell particles B is 0.5-1 cm.

8. The multiple shell powder processing and impurity removal process according to claim 1 is characterized in that: In step S4, the diameter of the grinding balls for the primary grinding is 2-3 mm, the grinding speed is 500-600 r / min, and the grinding time is 20-40 min. The screening uses a 230-270 mesh filter. The diameter of the grinding balls for the secondary grinding is 0.2-0.5 mm, the grinding speed is 500-600 r / min, and the grinding time is 5-15 min. The particle size of the crude shell powder is 25-40 μm, the drying temperature is 98-103 ° C, and the drying time is 20-30 min.

9. The multiple shell powder processing and impurity removal process according to claim 1, characterized in that: The high temperature calcination in step S5 is carried out at a temperature of 900-1000° C. and for a time of 3-4 hours.

10. The multiple shell powder processing and impurity removal process according to claim 1, characterized in that: The operating temperature of the ultraviolet disinfection cabinet in step S6 is 70-80° C., and the irradiation time is 5-8 minutes.

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