Preparation method and application of modified lithium magnesium ...

Detailed Description The present invention will be described in further detail with reference to specific examples. Example 1 The preparation method of the modified lithium magnesium silicate comprises the following steps of: (1) firstly, 0.1 part of beryllium chloride, 20 parts of magnesium chloride, 1 part of lithium chloride and 500 parts of pure water are added into a hydrothermal reaction kettle and fully stirred, then a sodium hydroxide solution with the mass fraction not more than 5% is added until the pH value of a reaction system is 8.0, and then the mixture is continuously and fully stirred for 10 min; (2) then adding 1 part of boric acid and 30 parts of silica sol, fully stirring for 10min, then sealing and heating to 110 ℃, and keeping the temperature to react for 60 min; (3) and stopping reaction discharging, filtering and fully washing the reaction solution, and roasting the collected filter cake at the high temperature of 300 ℃ for 10min to obtain the modified lithium magnesium silicate No. 1. Example 2 The modified lithium magnesium silicate is prepared from the following raw materials in parts by mass: (1) firstly, adding 0.25 part of beryllium sulfate, 0.25 part of beryllium nitrate, 25 parts of magnesium sulfate, 25 parts of magnesium nitrate, 2.5 parts of lithium sulfate, 2.5 parts of lithium nitrate and 500 parts of pure water into a hydrothermal reaction kettle, fully stirring, adding a sodium hydroxide solution with the mass fraction not more than 5% until the pH value of the reaction system is 12.0, and then, fully stirring for 30 min; (2) then adding 5 parts of boric acid and 60 parts of silica sol, fully stirring for 30min, then sealing and heating to 150 ℃, and keeping the temperature to react for 120 min; (3) and stopping reaction discharging, filtering and fully washing the reaction solution, and roasting the collected filter cake at 450 ℃ for 20min to obtain the modified lithium magnesium silicate No. 2. Example 3 The modified lithium magnesium silicate is prepared from the following raw materials in parts by mass: (1) firstly, 0.1 part of beryllium chloride, 0.1 part of beryllium sulfate, 0.1 part of beryllium nitrate, 10 parts of magnesium chloride, 10 parts of magnesium sulfate, 10 parts of magnesium nitrate, 1 part of lithium sulfate, 1 part of lithium nitrate, 1 part of lithium hydroxide and 500 parts of pure water are added into a hydrothermal reaction kettle and fully stirred, then a sodium hydroxide solution with the mass fraction not more than 5% is added until the pH value of the reaction system is 9.0, and then the mixture is continuously and fully stirred for 15 min; (2) then adding 2 parts of boric acid and 40 parts of silica sol, fully stirring for 15min, then sealing and heating to 120 ℃, and keeping the temperature to react for 80 min; (3) and stopping reaction discharging, filtering and fully washing the reaction solution, and roasting the collected filter cake at 350 ℃ for 15min to obtain the modified lithium magnesium silicate No. 3. Example 4 The modified lithium magnesium silicate is prepared from the following raw materials in parts by mass: (1) firstly, 0.15 part of beryllium chloride, 0.1 part of beryllium sulfate, 0.15 part of beryllium nitrate, 12 parts of magnesium chloride, 13 parts of magnesium sulfate, 11 parts of magnesium nitrate, 0.8 part of lithium chloride, 1.1 part of lithium sulfate, 0.7 part of lithium nitrate, 1.2 parts of lithium hydroxide and 500 parts of pure water are added into a hydrothermal reaction kettle and fully stirred, then sodium hydroxide solution with the mass fraction not more than 5% is added until the pH value of the reaction system is 11.0, and then the mixture is continuously and fully stirred for 25 min; (2) then adding 4 parts of boric acid and 50 parts of silica sol, fully stirring for 20min, then sealing and heating to 140 ℃, and keeping the temperature to react for 100 min; (3) and stopping reaction discharging, filtering and fully washing the reaction solution, and roasting the collected filter cake at the high temperature of 400 ℃ for 18min to obtain the modified lithium magnesium silicate No. 4. Comparative example 1 Beryllium chloride is not used (namely, the dosage of the beryllium chloride is changed to 0), the other reaction parameters and the process conditions are completely consistent with those of the example 1, and the prepared modified magnesium lithium silicate is marked as No. 5. Comparative example 2 The amounts of beryllium sulfate and beryllium nitrate were changed to 0.3 part, the remaining reaction parameters and process conditions were completely the same as in example 1, and the modified lithium magnesium silicate prepared was denoted as No. 6. Comparative example 3 The pH of the reaction system was adjusted to 7.0, the remaining reaction parameters and process conditions were completely the same as those in example 2, and the modified lithium magnesium silicate thus prepared was designated as No. 7. Comparative example 4 The pH of the reaction system was adjusted to 13.0, the remaining reaction parameters and process conditions were completely the same as those in example 2, and the modified lithium magnesium silicate thus prepared was designated as No. 8. Comparative example 5 Boric acid was not used but borax was used instead, and the remaining reaction parameters and process conditions were completely the same as those in example 3, and the modified lithium magnesium silicate thus prepared was denoted as No. 9. Comparative example 6 The amount of boric acid used was changed to 0.5 part, the remaining reaction parameters and process conditions were completely the same as those in example 3, and the modified lithium magnesium silicate thus prepared was designated as No. 10. Comparative example 7 The amount of boric acid was changed to 6 parts, the remaining reaction parameters and process conditions were completely the same as those in example 3, and the modified lithium magnesium silicate thus prepared was designated as No. 11. Comparative example 8 The high-temperature hydrothermal reaction temperature was changed to 105 ℃ and the remaining reaction parameters and process conditions were completely the same as those in example 4, and the modified lithium magnesium silicate thus prepared was denoted as No. 12. Comparative example 9 The high temperature hydrothermal reaction time was changed to 50min, and the remaining reaction parameters and process conditions were completely the same as in example 4, and the modified lithium magnesium silicate prepared was denoted as No. 13. Comparative example 10 The high temperature hydrothermal reaction time was changed to 130min, the remaining reaction parameters and process conditions were completely the same as in example 4, and the modified lithium magnesium silicate prepared was denoted as No. 14. Comparative example 11 The high-temperature hydrothermal reaction temperature was changed to 155 ℃ and the remaining reaction parameters and process conditions were completely the same as those in example 4, and the modified lithium magnesium silicate thus prepared was designated as No. 15. Comparative example 12 BO is generated in the reaction kettle3 3-/SiO2Regeneration of Li+/Be(OH)2-Mg(OH)2The coprecipitation was carried out, the remaining reaction parameters and process conditions were completely the same as those in example 4, and the modified lithium magnesium silicate thus prepared was designated as No. 16. Comparative example 13 Only 0.8 part of lithium chloride (i.e., 1.1 part of lithium sulfate, 0.7 part of lithium nitrate, 1.2 parts of lithium hydroxide were not added) was added, and the remaining reaction parameters and process conditions were completely the same as those in example 4, and the modified lithium magnesium silicate thus prepared was denoted by No. 17. Comparative example 14 1.5 parts of lithium chloride, 1 part of lithium sulfate, 1.5 parts of lithium nitrate and 1.5 parts of lithium hydroxide (namely, the total amount of the lithium salts is 5.5 parts) are added, the rest reaction parameters and process conditions are completely consistent with those of example 4, and the prepared modified lithium magnesium silicate is marked as No. 18. The modified magnesium lithium silicates No.1 to 18 prepared in the above examples, montmorillonite for import feed (model: VEEGUM-K2, manufactured by Vanderbilt, USA), and magnesium lithium silicate for import feed (model: XLL-A, manufactured by BYK, Germany) were evaluated in vitro by ELISA under the same conditions, and the results of comparative tests of negative charge numbers (measured by the number of charges of cell layers) and adsorption forces thereof to aflatoxin B1 (AFB 1), Zearalenone (ZEA), vomitoxin (DON), Ochratoxin (OTA), and fumonisin B1 (FUMB 1) are shown in Table 1. Table 1 comparative test data As can be seen from table 1 comparing the test data: (1) the reaction parameters and process conditions must be strictly limited within the technical requirements of the invention, otherwise, the prepared product almost completely has no layered structure, so the adsorption capacity to mycotoxin is poor and the product has no practicability. (2) The modified magnesium lithium silicate prepared by the invention has high negative charge number (the charge number of a unit cell layer is as high as 0.68 and above), strong electrochemical adsorption capacity, excellent adsorption capacity (up to 100%) for mycotoxins with larger polarity such as AFB1 and the like, ideal adsorption capacity for mycotoxins with lower polarity such as ZEA, DON and the like, and obviously better adsorption effect than similar products imported from abroad, so the modified magnesium lithium silicate has extremely bright application prospect in industries such as feed mildew resistance and detoxification and the like. The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.