CN100469435C - A kind of preparation method of ferrocyanide/silicon dioxide hybrid material with high loading capacity - Google Patents

Abstract

The invention discloses a method for preparing a ferrocyanide/silicon dioxide hybrid material with a high loading capacity, relating to a method for preparing a radionuclide ion absorbing material. The method is to react salt solutions of metal ions such as Mn, Sn, Ti, Fe, Ni, Co, Cr, Zr, Cu, Pb, Zn and potassium ferrocyanide (sodium) to obtain ferrocyanide nanoparticles . The particle is fixed with silica sol in the water system or polymerized alkyl siloxane in the organic solvent, and then an appropriate amount of inorganic acid, organic amine or ammonia water is added to obtain a hybrid gel. The obtained gel is dried, ground and sieved to obtain a ferrocyanide/silicon dioxide hybrid material with a high loading capacity. The material has a high loading capacity of ferrocyanide and strong adsorption capacity for nuclide ions. In addition, the material strength can meet the requirements of packed beds, and the particle size is controllable, which avoids the excessive water resistance of the bed caused by the use of ferrocyanide alone. question.

Description

A kind of preparation method of ferrocyanide/silicon dioxide hybrid material with high loading capacity

technical field

The invention relates to a preparation method of a radionuclide ion absorption material, in particular to a preparation method of a ferrocyanide/silicon dioxide hybrid material with a high loading capacity, and belongs to the technical field of material preparation and radioactive waste water treatment.

Background technique

my country's energy policy has changed from "moderately developing nuclear power" to "actively developing nuclear power". By 2020, the domestic nuclear power installed capacity will increase from the current 8 million kW to about 40 million kW. After 2020, there will be even greater development. Whether the radioactive wastewater produced by the nuclear industry can be properly disposed of is one of the key links related to nuclear safety. It is a very meaningful work in the field of nuclear industry to research and develop efficient and highly selective radioactive wastewater treatment technology to maximize the miniaturization of waste. The commonly used methods for the treatment of radioactive wastewater are as follows:

1) Evaporation and concentration method: After the radioactive waste water is evaporated and concentrated, the distillation residue is solidified and disposed of, and the distillate is discharged after being treated with ion exchange resin. This method consumes a lot of energy, and due to the high salt content of radioactive waste water, the corrosion of the evaporation device is very serious.

2) Natural aluminosilicate treatment method, which is to use natural aluminosilicates such as kaolin, rectorite, and vermiculite to treat radioactive wastewater with certain ion exchange capabilities, in order to fix radionuclide ions inside these materials, Complete the treatment of waste water. However, these materials have limited ion exchange capacity and poor selectivity to nuclide ions, resulting in a large amount of radioactive waste, which requires further treatment and disposal.

3) Zeolite treatment method: natural zeolite or artificially synthesized zeolite has a suitable regular space structure and can absorb and treat radionuclides. Theoretically, the exchange capacity of zeolite for Cs can reach 2meq/g, but in practice, other ions such as potassium ions will strongly interfere with the removal of Cs, resulting in a very low adsorption capacity of zeolite, which can only treat 10 kg of wastewater per kg of zeolite. Since the adsorbent cannot be regenerated in the treatment of radioactive wastewater, a large amount of radioactive waste generated needs further treatment and disposal.

4) Ion-exchange resin treatment method; at present, the ion-exchange resins used by my country's nuclear facilities to treat low- and medium-level radioactive waste liquids are mostly strong-acid and strong-base types with styrene divinylbenzene as the matrix. Typically, the adsorption capacity utilization of the resin is less than 30%. The resin lacks sufficient selectivity to the radionuclides in the medium and low-level radioactive waste liquid, and the resin is used for one-time use without regeneration. Therefore, a large amount of radioactive waste resin is produced, and the post-processing cost is quite astonishing. In addition, the resin is an organic material with poor radiation resistance, and hydrogen gas may be generated by radiation decomposition, which has become a major hidden danger for long-term storage of radioactive waste resin.

5) Ammonium phosphomolybdate treatment method: Ammonium phosphomolybdate has a high selectivity to Cs ⁺ , however, ammonium phosphomolybdate is a fine crystal and cannot be operated in a packed bed, which severely limits its industrial application. Sun Zhaoxiang and others prepared hybrid materials of ammonium phosphomolybdate and tetravalent metal phosphate (such as Ti, Zr, Sb, etc.), and realized the granulation of ammonium phosphomolybdate (Ion Exchange and Adsorption, 12, 44-49, 1996 ; Nuclear Chemistry and Radiation Chemistry, 21,76-82,1999; Journal of Beijing Normal University: Natural Science Edition, 27,339-343,1991), but the introduction of more expensive tetravalent metals increases the cost. According to the technical report on radioactive waste treatment issued by the International Atomic Energy Agency in 2002, ammonium phosphomolybdate series materials have not yet been used in large-scale practical applications in radioactive wastewater treatment.

6) Ferrocyanide treatment method: Ferrocyanide immobilized by transition metals has good selective absorption capacity for radioactive Cs ⁺ and Sr ²⁺ ions. In the case of a Na ⁺ concentration of 5 mol/L, the selectivity coefficient (for Na ⁺ ) of this type of material to Cs ⁺ reaches 1,500,000 (Nuclear Science and Engineering, 137, 206-214, 2001). However, the internal mass transfer conditions of ferrocyanide particles are poor, and the adsorption capacity is often not fully utilized (Nuclear Chemistry and Radiation Chemistry, 23, 108-113, 2001). Loading ferrocyanide on porous material supports can improve the kinetic conditions of mass transfer. Mardan studied the use of solvent evaporation method and the use of porous silica as a carrier to immobilize K ₂ [CoFe(CN) ₆ ] (Separation and Purification Technology 16, 147-158, 1999), and the highest loading capacity was only 1.36g K ₂ [CoFe(CN) ₆ ]/g-SiO ₂ , and the solvent evaporation step needs to be repeated many times, the steps are cumbersome, and a large amount of organic solvent is consumed, so the possibility of practical application is not great (Talanta, 17-23, 955, 1970) . Wang Qiuping and others prepared various materials such as calcium potassium ferrocyanide, zinc potassium ferrocyanide, and manganese potassium ferrocyanide by co-precipitation under acidic conditions, all of which have good adsorption capacity for Cs ions, but neither Due to the poor stability of the particles, they are easily crushed and pulverized in actual operation, and cannot be used for the treatment of radioactive wastewater (Ion Exchange and Adsorption, 16(3), 225-233, 2000). Terada (Talanta 1970, 17, 955-963) and Konecny (Radioanal.Chem., 1973, 14, 255-266) both reported that potassium ferrocyanide was first fixed in silica gel, and then transition metal ions to convert it into ferrocyanide absorbent. However, since the conversion reaction is carried out in the pores of silica, its speed is extremely slow, a large excess of metal ions needs to be used, and the product composition of the conversion reaction is difficult to control. Part of the potassium ferrocyanide in the gel was leached and lost during the ion absorption process.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of low ferrocyanide loading, difficult granulation, low particle strength, and insufficient fixation of potassium ferrocyanide (sodium) in the prior art, thereby providing a method for preparing high-loading ferrocyanide. The ferrocyanide/silica hybrid material method ensures that the material has high adsorption capacity and selectivity at the same time.

The purpose of the present invention is achieved by the following technical scheme: a kind of preparation method of ferrocyanide/silicon dioxide hybrid material of high loading capacity, it is characterized in that the method is carried out as follows:

1) Preprecipitation: Dissolve potassium ferrocyanide or sodium ferrocyanide in deionized water, add Mn, Sn, Ti, Fe, Ni, Co, Cr, Zr, Cu, Pb, Soluble salt solution of Zn transition metal, the molar ratio of hexacyanoferrate to metal ion is 1:1~1:6, and the precipitate is centrifuged and washed several times to obtain ferrocyanide nanoparticles;

2) Gel fixation: fixation with silica sol in water system or polymeric alkyl siloxane in organic solvent:

2.1) Fixed with silica sol in water system

Add alkaline silica sol aqueous solution to the obtained ferrocyanide nanoparticles under vigorous stirring, the mass ratio of ferrocyanide nanoparticles to silicon dioxide in the silica sol is 0.2:1~7:1, and then put the ferrocyanide nanoparticles in a water bath Heat the system to 40-80°C, add an inorganic acid, any one or a mixture of several selected from hydrochloric acid, sulfuric acid, nitric acid or phosphoric acid; adjust the pH of the system to 2-7, and place the resulting gel in a constant temperature oven Dry to constant weight in medium to obtain ferrocyanide/silicon dioxide hybrid material;

2.2) Fixation with polymeric alkyl siloxane in organic solvent

Dissolve the alkoxysilane in an organic solvent, the alkoxysilane is selected from a mixture of 1 to 3 kinds of tetramethoxysilane, tetraethoxysilane and tetrapropoxysilane, and the organic solvent is selected from methanol, ethanol and 1 to 3 mixtures in acetone; add deionized water and concentrated hydrochloric acid under stirring to form a mixed solution, the amount of organic solvent added is 1 to 2 times the volume of alkoxysilane, and the amount of HCl and H2O added is alkoxysilane 0.01 to 0.1 times and 0.4 to 1.8 times the molar weight of oxysilane; heat the mixed solution to reflux to 60 to 90°C and keep it for 2 to 8 hours to obtain a solution of polyalkylsiloxane; prepare the polyalkylsiloxane in step 1) Ferrocyanide nanoparticles are washed with ethanol, and then dispersed in polyalkylsiloxane solution, and the mass ratio of ferrocyanide to silicon dioxide in the system is 0.2:1~7:1; after fully stirring and dispersing , add a mixture of 1 to 4 kinds of ammonia water, methylamine, ethylamine and ethylenediamine dropwise under stirring, and the addition amount is 1/20~1/10 of the volume of the original alkoxysilane to form a gel, and the obtained The gel was dried in a constant temperature oven to a constant weight to obtain a ferrocyanide/silica hybrid material.

The technical feature of the present invention is also that; the preferred molar ratio of hexacyanoferrate and metal ions in the step 1) is 1:1.5-1:3. The preferred mass ratio of ferrocyanide nanoparticles to silicon dioxide in the steps 2.1) and 2.2) is 0.5; 1-4:1. The preferred temperature to which the system is heated in a water bath in the step 2.1) is 70-80°C. The polymerization reaction in the step 2.2) is carried out at a temperature 5-10° C. higher than the boiling point of the solvent.

The silicon dioxide content in the alkaline silica sol aqueous solution in step 2.1) of the present invention is 10-35 wt%, wherein the silicon dioxide particles have a particle size of 10-40nm and a density of 1.1-1.3g/mL.

This method avoids the use of formed porous silica as a carrier, but uses a liquid precursor of silica (silica sol or polysiloxane) to mix with ferrocyanide to initiate a gel reaction, thereby obtaining a ferrocyanide. Hybrid materials with high ferricyanide loading. The method has the following advantages: (a) Large ferrocyanide load: the ferrocyanide load of the material obtained by the method can reach more than 80%. (b) The ferrocyanide in the material is dispersed in the hybrid material in the form of tiny particles, and the silica acts as a carrier of ferrocyanide, which can meet the strength requirements. (c) The prepared ferrocyanide/silica hybrid material has a porous structure, which can improve the adsorption kinetic conditions and increase the adsorption rate. (d) The material prepared by the present invention not only exerts the high-efficiency adsorption performance of nano-scale ferrocyanide, but also satisfies the particle size and strength required for packed bed operation.

The adsorption material prepared by this method can reduce the concentration of Cs ⁺ in water from 1000 μg/L to below 8 μg/L under the interference of 0.5 mol/L Na ⁺ and 0.5 mol/L H ⁺ , while the adsorbent The dosage is only 2g/L.

Detailed ways

The preparation method of a ferrocyanide/silicon dioxide hybrid material with a high loading capacity provided by the present invention, its specific process steps are as follows:

1) Preprecipitation: Dissolve potassium ferrocyanide or sodium ferrocyanide in deionized water, add Mn, Sn, Ti, Fe, Ni, Co, Cr, Zr, Cu, Pb, Soluble salt solution of Zn transition metal, the molar ratio of hexacyanoferrate to metal ion is 1:1~1;6, preferably 1:1.5~1:3; the precipitate is centrifuged and washed several times to obtain ferrous iron Cyanide nanoparticles;

2) Gel fixation: fixation with silica sol in water system or polymeric alkyl siloxane in organic solvent:

2.1) Fixed with silica sol in water system

Add alkaline silica sol aqueous solution to the obtained ferrocyanide nanoparticles under vigorous stirring, the silica content in the alkaline silica sol aqueous solution is 10-35wt%, wherein the silica particles have a particle size of 10-40nm and a density of 1.1 ~1.3g/mL. The mass ratio of ferrocyanide nanoparticles to silica in silica sol is 0.2:1-7:1, preferably 0.5:1-4:1; then heat the system to 40-80°C in a water bath , preferably at 70-80°C, adding an inorganic acid, selected from any one of hydrochloric acid, sulfuric acid, nitric acid or phosphoric acid or a mixture of several thereof; adjusting the pH of the system to 2-7, preferably 4-6; The glue was dried in a constant temperature oven to a constant weight to obtain a ferrocyanide/silica hybrid material;

2.2) Fixation with polymeric alkyl siloxane in organic solvent

Dissolve the alkoxysilane in an organic solvent, the alkoxysilane is selected from a mixture of 1 to 3 kinds of tetramethoxysilane, tetraethoxysilane and tetrapropoxysilane, and the organic solvent is selected from methanol, ethanol and 1 to 3 mixtures in acetone; add deionized water and concentrated hydrochloric acid under stirring to form a mixed solution, the amount of organic solvent added is 1 to 2 times the volume of alkoxysilane, and the amount of HCl and H ₂ O added are respectively 0.01 to 0.1 times and 0.4 to 1.8 times the molar weight of alkoxysilane; heat the mixed solution to reflux to 60 to 90°C, preferably 5 to 10°C higher than the boiling point of the solvent; keep it for 2 to 8 hours to obtain polyalkane A solution of polyalkylsiloxane; the ferrocyanide nanoparticles prepared in step 1) are washed with ethanol, and then dispersed in the polyalkylsiloxane solution, and the ferrocyanide nanoparticles and the silicon dioxide in the system The mass ratio is 0.2:1 to 7:1; after fully stirring and dispersing, add a mixture of 1 to 4 kinds of ammonia water, methylamine, ethylamine and ethylenediamine dropwise under stirring, and the amount added is the original alkoxysilane 1/20-1/10 of the volume to form a gel, and the obtained gel is dried in a constant temperature oven to a constant weight to obtain a ferrocyanide/silicon dioxide hybrid material.

Several specific examples are enumerated below to further understand the present invention.

Example 1:

Dissolve 9 g of potassium ferrocyanide in 50 mL of deionized water, slowly add 50 mL of Co(NO ₃ ) ₂ solution under vigorous stirring, the molar ratio of K ₄ [Fe(CN) ₆ ]) to Co ions=1:1.5, and then The system was stirred for 30min, aged for 24hr, filtered and washed. The obtained nanoscale K ₂ [CoFe(CN) ₆ ] particles were dispersed in 50 mL of deionized water, and 115 mL of alkaline silica sol with a silica content of 30% (wt) was added, and K ₂ [CoFe(CN) ₆ ] in the system The mass ratio to silicon dioxide is 0.2/1. Stir well and mix evenly, heat to 80°C in a water bath, then add 35% concentrated hydrochloric acid under vigorous stirring, adjust the pH to 5, let the system stand still, gel after 1min, and dry the gel at 100°C To constant weight, grind and pass through a 60-mesh sieve. The radionuclide ion absorbing material is obtained, and its active component is K ₂ [CoFe(CN) ₆ ].

Example 2:

Dissolve 15g of sodium ferrocyanide in 80mL of deionized water, slowly add 80mL of Zn(NO ₃ ) ₂ solution under vigorous stirring, the molar ratio of Na ₄ [Fe(CN) ₆ ] to Zn ions=1:2, and then add The system was stirred for 60 minutes, aged for 12 hours, filtered and washed. The obtained Na ₂ [CoFe(CN) ₆ ] particles were dispersed in 80 mL of deionized water, and then 50 mL of alkaline silica sol with a silica content of 25% (wt) was added. In the system, Na ₂ [ZnFe(CN) ₆ ] and The mass ratio of silicon dioxide is 0.9/1. After fully stirring and mixing evenly, heat to 40°C in a water bath, then add 65% concentrated nitric acid under vigorous stirring, adjust the pH to 4, let the obtained gel system stand still, and dry the gel at 120°C until constant Heavy, ground, and passed through a 60-mesh sieve to obtain a radionuclide ion absorbing material, the active component of which is Na ₂ [ZnFe(CN) ₆ ].

Example 3:

Dissolve 1Kg of potassium ferrocyanide in 5.6L of deionized water, slowly add 5L of Mn(NO ₃ ) ₂ solution under vigorous stirring, the molar ratio of K ₄ [Fe(CN) ₆ ] to Mn ions=1:1, and then The system was stirred for 20min, aged for 48hr, filtered and washed. Gained K ₂ [MnFe(CN) ₆ ] nanoparticles were dispersed in 4L deionized water, and then 315 mL of alkaline silica sol with a silicon dioxide content of 30% (wt) was added, and K ₂ [MnFe(CN) ₆ ] in the system The mass ratio to silicon dioxide is 7/1. After fully stirring and mixing evenly, heat to 80°C in a water bath, then add sulfuric acid (1:1) under vigorous stirring, adjust the pH to 5, let the obtained gel stand still, dry at 100°C to constant weight, and grind , through a 50-mesh sieve to obtain a radionuclide ion absorbing material, the active component of which is K ₂ [MnFe(CN) ₆ ].

Example 4:

Dissolve 15g of potassium ferrocyanide in 80mL of water, slowly add 100mL of Cu(NO ₃ ) ₂ solution under vigorous stirring, the molar ratio of K ₄ [Fe(CN) ₆ ] to Cu ions=1:6, stir for 45min, and stand After 12hr, filter and wash. Gained precipitation is dispersed in 50mL deionized water, then add 20mL silica content and be the alkaline silica sol of 30% (wt), the mass ratio of Cu ₂ [Fe(CN) ₆ ] and silica in the system is 1.6/ 1. Stir well and mix evenly, heat to 70°C in a water bath, then add sulfuric acid (1:1) under vigorous stirring, adjust the pH to 5, the system gels quickly, let the obtained gel stand still, and bake at 110°C Dry to constant weight, grind, and pass through a 50-mesh sieve to obtain a radionuclide ion absorbing material, the active component of which is Cu ₂ [Fe(CN) ₆ ].

Example 5:

Dissolve 50g of potassium ferrocyanide in 250mL of deionized water, slowly add 250mL of Ni(NO ₃ ) ₂ solution under vigorous stirring, the molar ratio of K ₄ [Fe(CN) ₆ ] to Ni ions=1:5, and stir for 30min , aged for 24hr, filtered and washed. Gained precipitation is dispersed in 200mL deionized water, then add 60mL silica content and be the alkaline silica sol of 25% (wt), in the system Ni ₂ [Fe(CN) ₆ ] and the mass ratio of silica are 2.16/ 1. After mixing evenly, heat it in a water bath to 80°C, add 60% concentrated nitric acid to adjust the pH to 6, and the system loses fluidity and gels within 30 seconds. The obtained gel was dried at 80°C to constant weight, ground, and passed through a 100-mesh sieve to obtain a radionuclide ion absorbing material, the active component of which was Ni ₂ [Fe(CN) ₆ ].

Embodiment 6:

Dissolve 100g of potassium ferrocyanide in 700mL of water, add 500mL of Cu(NO ₃ ) ₂ solution under vigorous stirring, the molar ratio of K ₄ [Fe(CN) ₆ ] to Cu ions=1:4, stir for 40min, and age 48hr, filter and wash. Gained precipitation is dispersed in 500mL deionized water, then add 35mL of silica content and be the alkaline silica sol of 30% (wt), the mass ratio of Cu ₂ [Fe(CN) ₆ ] and silica in the system is 6.3/ 1. After mixing evenly, heat it in a water bath to 80°C, add 60% concentrated nitric acid to adjust the pH to 4, and the system loses fluidity and gels within 10 minutes. The resulting gel was dried at 100°C until constant weight, ground, and passed through a 50-mesh sieve to obtain a radionuclide ion absorbing material, the active component of which was Cu ₂ [Fe(CN) ₆ ].

Embodiment 7:

Dissolve 40g of potassium ferrocyanide in 220mL of water, add 250mL of Sn(NO ₃ ) ₂ solution under vigorous stirring, the molar ratio of K ₄ [Fe(CN) ₆ ] to Sn ions=1:1.6, stir for 20min, and age 24hr, filter and wash. The resulting precipitate was dispersed in 200mL deionized water, and then 60mL of alkaline silica sol with a silicon dioxide content of 20% (wt) was added, and the mass ratio of K ₂ [SnFe(CN) ₆ ] to silicon dioxide in the system was 2.7/ 1. After mixing evenly, heat in a water bath to 80°C, then add phosphoric acid to adjust the pH to 5, and the system gels. The obtained gel was dried at 100°C to constant weight, ground, and passed through a 100-mesh sieve to obtain a radionuclide ion absorbing material, the active component of which was K ₂ [SnFe(CN) ₆ ].

Embodiment 8:

Dissolve 20g of potassium ferrocyanide in 100mL of water, add 120mL of Pb(NO ₃ ) ₂ solution under vigorous stirring, the molar ratio of K ₄ [Fe(CN) ₆ ] to Pb ions=1:2, stir for 45min, and age 36hr, filtered and washed three times with deionized water. Disperse in 100mL of polytetraethoxysilane in acetone solution (silicon dioxide content is 15g, its preparation method is as follows: take 52g of tetraethoxysilane dissolved in 100mL of acetone, heat to 60°C under reflux and stirring, keep for 4hr, The mass ratio of K ₂ [PbFe(CN) ₆ ] and silicon dioxide in the system was 1.57/1. Add 6.5mL of 30wt% ammonia water to the solution under stirring, and the system gels quickly. The resulting gel is dried at 120°C to constant weight, ground, and passed through a 100-mesh sieve to obtain a radionuclide ion-absorbing material. Divided into K ₂ [PbFe(CN) ₆ ].

Embodiment 9:

Dissolve 10g of potassium ferrocyanide in 100mL of water, add 120mL of CrCl ₃ solution K ₄ [Fe(CN) ₆ ] to Cr ion molar ratio = 1:1.5 under vigorous stirring, stir for 70min, age for 10hr, filter, remove Washed three times with deionized water. Disperse in 40mL of ethanol solution of polytetrapropoxysilane (the content of silicon dioxide is 6g, the preparation method is as follows: take 27g of tetrapropoxysilane and dissolve it in 50mL of ethanol, heat it to 90°C under reflux and stir, and keep it for 8hr , to obtain 53mL ethanol solution of polytetrapropoxysilane) The mass ratio of K[CrFe(CN) ₆ ] and silicon dioxide in the system was 1.2/1. Add 2mL of ethylenediamine to the solution under stirring, dry the resulting gel at 110°C to constant weight, grind, and pass through a 100-mesh sieve to obtain a radionuclide ion-absorbing material, whose active component is K[CrFe( CN) ₆ ].

Example 10:

Dissolve 18g of potassium ferrocyanide in 100mL of deionized water, slowly add 110mL of Co(NO ₃ ) ₂ solution under vigorous stirring, the molar ratio of K ₄ [Fe(CN) ₆ ]) to Co ions=1:1.5, and then The system was stirred for 30 minutes, aged for 24 hours, filtered and washed with deionized water three times. Disperse in 85mL of methanol solution of polytetramethoxysilane (the content of silicon dioxide is 15g, the preparation method is as follows: dissolve 38g of tetramethoxysilane in 47mL of methanol, heat to 70°C under reflux and stirring, and keep for 2hr , to obtain 85 mL of methanol solution of polytetramethoxysilane) in the system, the mass ratio of K ₂ [CoFe(CN) ₆ ] to silicon dioxide was 1/1. Add 2.4 mL of methylamine to the solution under stirring, dry the resulting gel at 90°C until constant weight, grind, and pass through a 100-mesh sieve to obtain a radionuclide ion-absorbing material, the active component of which is K ₂ [CoFe (CN) ₆ ].

Claims (6)

1, a kind of preparation method of ferrocyanide/silicon dioxide hybrid material of high loading capacity, it is characterized in that the method is carried out as follows: 1) Preprecipitation: Dissolve potassium ferrocyanide or sodium ferrocyanide in deionized water, add Mn, Ti, Fe, Ni, Co, Cr, Zr, Cu, Zn transition metals to it under vigorous stirring Soluble salt solution, the molar ratio of hexacyanoferrate to metal ions is 1:1-1:6, and the precipitate is centrifuged and washed several times to obtain ferrocyanide nanoparticles; 2) Gel fixation: fix with silica sol in water system or fix with polyalkoxysilane in organic solvent: 2.1) Fixed with silica sol in water system Add alkaline silica sol aqueous solution to the obtained ferrocyanide nanoparticles under vigorous stirring, the mass ratio of ferrocyanide nanoparticles to silicon dioxide in the silica sol is 0.2:1～7:1, and then dissolve the ferrocyanide nanoparticles in a water bath Heat the system to 40-80°C, add an inorganic acid, any one or a mixture of several selected from hydrochloric acid, sulfuric acid, nitric acid or phosphoric acid; adjust the pH of the system to 2-7, and place the resulting gel in a constant temperature oven Dry to constant weight in medium to obtain ferrocyanide/silicon dioxide hybrid material; 2.2) Fixed with polyalkoxysilane in organic solvent Dissolve the alkoxysilane in an organic solvent, the alkoxysilane is selected from a mixture of 1 to 3 kinds of tetramethoxysilane, tetraethoxysilane and tetrapropoxysilane, and the organic solvent is selected from methanol, ethanol and 1 to 3 mixtures in acetone; add deionized water and concentrated hydrochloric acid under stirring to form a mixed solution, the amount of organic solvent added is 1 to 2 times the volume of alkoxysilane, and the amount of HCl and H ₂ O added are respectively 0.01 to 0.1 times and 0.4 to 1.8 times the molar weight of alkoxysilane; heat the mixed solution to reflux to 60 to 90°C and keep it for 2 to 8 hours to obtain a solution of polyalkoxysilane; prepare in step 1) The ferrocyanide nanoparticles were washed with ethanol, and then dispersed in the polyalkoxysilane solution, and the mass ratio of ferrocyanide nanoparticles to silicon dioxide in the system was 0.2:1 to 7:1; fully stirred After dispersion, add a mixture of ammonia water, methylamine, ethylamine and ethylenediamine dropwise under stirring. The amount added is 1/20 to 1/10 of the volume of the original alkoxysilane to form a gel. The resulting gel was dried in a constant temperature oven to a constant weight to obtain a ferrocyanide/silicon dioxide hybrid material. 2. The method for preparing ferrocyanide/silicon dioxide hybrid material with high loading capacity according to claim 1, characterized in that the molar ratio of hexacyanoferrate to metal ions in said step 1) It is 1:1.5～1:3. 3. The method for preparing ferrocyanide/silicon dioxide hybrid material with high loading capacity as claimed in claim 1 or 2, characterized in that: the dihydrogen in the alkaline silica sol aqueous solution in the step 2.1) The silicon oxide content is 10-35 wt%, wherein the silicon dioxide particles have a particle diameter of 10-40nm and a density of 1.1-1.3g/mL. 4. The method for preparing ferrocyanide/silicon dioxide hybrid material with high loading capacity as claimed in claim 1 or 2, characterized in that: in the steps 2.1) and 2.2), ferrocyanide nanoparticles and The mass ratio of silicon dioxide is 0.5:1 to 4:1. 5. The method for preparing high-capacity ferrocyanide/silicon dioxide hybrid material according to claim 1, characterized in that: in the step 2.1), the system is heated to 70-80°C. 6. The method for preparing high-capacity ferrocyanide/silica hybrid material according to claim 1, characterized in that: said step 2.2) polymerizes at a temperature 5-10°C higher than the boiling point of the solvent next.