Disclosure of Invention
In view of the above, the present invention provides a method for preparing amidoxime-silica resin capable of adsorbing gallium.
In order to solve the technical problem, the invention discloses a preparation method of amidoxime-silica resin for adsorbing gallium, which comprises the following steps:
step 1, preparing acrylonitrile-silicon dioxide resin (PAN/SiO)2): synthesizing acrylonitrile-silicon dioxide resin (PAN/SiO) by using mesoporous silicon dioxide microspheres as a framework and acrylonitrile as a raw material through a solution polymerization method2);
Step 2, preparing amidoxime-silicon dioxide resin (PAO/SiO) for adsorbing gallium2): acrylonitrile-silicon dioxide globule is modified by grafting amidoxime functional group through amidoximation reaction to obtain amidoxime-silicon dioxide resin (PAO/SiO) for absorbing gallium2)。
Alternatively, the preparation of acrylonitrile-silica resin (PAN/SiO) in the step 12) The synthetic route is as follows:
the method comprises the following steps: selecting silicon dioxide particles as a framework; putting the silicon dioxide particles into a rotary evaporation flask, pumping the silicon dioxide particles to negative pressure by using a vacuum pump, connecting a nitrogen bottle, introducing nitrogen, and vacuumizing; then the mixture of monomer, diluent and initiator is sucked back into the flask; adjusting the rotation speed of the rotary evaporator to fully mix the mixture with the silicon dioxide particles; thereafter, heating in a silicon oil bath; the obtained silicon dioxide grafted acrylonitrile resin is respectively treated with acetone and acetoneWashing with water to remove physically attached polymer, drying under vacuum to obtain grafted particles PAN/SiO2。
Optionally, the particle size of the silica particles is 70-150 μm; the vacuumizing time is 25-35 minutes.
Alternatively, the monomer: diluent agent: the mass ratio of the initiator is 90-110: 320-380: 0.5-1.5.
Optionally, the monomer is a monomer with a mass ratio of 20: 80-10: 90 of divinylbenzene and acrylonitrile; the diluent is acetophenone and diethyl phthalate with the mass ratio of 3: 2; the initiator is azobisisobutyronitrile.
Alternatively, the heating in the silicon oil bath is specifically: slowly heating to 343K, maintaining for 0.5-1.5 h, then heating at 353K for 1.5-2.5 h, and finally heating to 363K for 6.5-7.5 h.
Alternatively, the synthetic route for preparing the amidoxime-silica resin adsorbing gallium in the step 2 is as follows:
the method comprises the following steps: mixing deionized water and ethanol; hydroxylamine hydrochloride was dissolved in the mixed solution under a nitrogen atmosphere, followed by sodium carbonate added under magnetic stirring at room temperature, and on the other hand, PAN/SiO was added2Adding the resin and the mixed solution into a three-neck flask, installing a condensation return device, heating the system to 343K, and heating in a water bath under a nitrogen atmosphere; filtering, washing and drying to finally obtain the synthetic PAO/SiO2And (3) resin.
Optionally, the volume ratio of the deionized water to the ethanol is 1: 1; the mass volume ratio (g/ml) of the hydroxylamine hydrochloride to the deionized water is 5:100-10:100, and the mass volume ratio (g/ml) of the sodium carbonate to the deionized water is 3:100-5: 100.
Optionally, said PAN/SiO2The mass volume ratio (g/ml) of the resin to the deionized water is 8:100-12: 100; the water bath time is 2.5h-3.5 h.
Compared with the prior art, the invention can obtain the following technical effects:
1) the resin adsorbent has a developed ordered mesoporous structure, a large specific surface area, good mechanical strength and chemical stability, is suitable for separating and recovering gallium in Bayer solution, does not need to add any chemical reagent in the reaction process, is pollution-free and does not generate any waste.
2) The resin has high gallium adsorption capacity, high adsorption speed and good selectivity, and has wide market prospect.
Of course, it is not necessary for any one product in which the invention is practiced to achieve all of the above-described technical effects simultaneously.
Detailed Description
The following embodiments are described in detail with reference to the accompanying drawings, so that how to implement the technical features of the present invention to solve the technical problems and achieve the technical effects can be fully understood and implemented.
The invention discloses a preparation method of amidoxime-silicon dioxide resin for adsorbing gallium, which comprises the following steps:
step 1, PAN/SiO2The preparation of the resin comprises the following synthetic route:
the method comprises the following steps: silica particles of 70 to 150 μm are selected as the backbone of the polymer resin. The silica particles were placed in a rotary evaporation flask and pumped to negative pressure using a vacuum pump, then a nitrogen cylinder was connected, nitrogen gas was introduced, and vacuum was applied for 25-35 minutes. Then mixing the monomer, diluent and initiatorThe contents were back-sucked into the flask, where monomer: diluent agent: the mass ratio of the initiator is 90-110: 320-380: 0.4-1.5; the mass ratio of the monomers is 20: 80-10: 90 of Divinylbenzene (DVB) and acrylonitrile; the diluent is acetophenone and diethyl phthalate with the mass ratio of 3: 2; the initiator is azobisisobutyronitrile; the rotation speed of the rotary evaporator was adjusted to sufficiently mix the mixture with the silica particles. After that, the mixture is slowly heated to 343K in a silicon oil bath for 0.5h to 1.5h, then heated at 353K for 1.5h to 2.5h, and finally heated to 363K for 6.5h to 7.5 h. Washing the obtained silica grafted acrylonitrile resin with acetone and water respectively to remove physically attached polymers, drying under vacuum, and finally obtaining grafted particles PAN/SiO2。
Step 2, PAO/SiO2The preparation of the resin comprises the following synthetic route:
the method comprises the following steps: taking deionized water and ethanol according to the volume ratio of 1:1, mixing; dissolving hydroxylamine hydrochloride in the mixed solution under nitrogen atmosphere, wherein the mass volume ratio (g/ml) of the hydroxylamine hydrochloride to the deionized water is 5:100-10:100, and then adding sodium carbonate under magnetic stirring at room temperature, wherein the mass volume ratio (g/ml) of the sodium carbonate to the deionized water is 3:100-5: 100; on the other hand, PAN/SiO2The resin and the mixed solution were charged into a three-necked flask in which PAN/SiO was placed2The mass volume ratio (g/ml) of the resin to the deionized water is 8:100-12: 100; a condensation return device is arranged, then the system is heated to 343K and is kept in a water bath for 2.5h-3.5h under nitrogen atmosphere; filtering, washing and drying to finally obtain the synthetic PAO/SiO2And (3) resin.
Example 1 PAO/SiO with a degree of crosslinking of 8% and an organic content of 20%2Preparation of
The silica particles were placed in a rotary evaporation flask and pumped to negative pressure using a vacuum pump, then a nitrogen cylinder was connected, nitrogen gas was introduced, and vacuum was applied for 30 minutes. Then 25g of the monomer (E.M.)DVB and acrylonitrile in a 15:85 ratio by mass), a mixture of 350g of diluent (acetophenone and diethyl phthalate in a 3:2 ratio by mass) and 1g of initiator (azobisisobutyronitrile) was sucked back into the flask. The rotation speed of the rotary evaporator was adjusted to sufficiently mix the mixture with the silica particles. Thereafter, it was slowly heated in a silicon oil bath to 343K for 1 hour, then 353K for 2 hours and finally 363K for 7 hours. Washing the obtained silica grafted acrylonitrile resin with acetone and water respectively to remove physically attached polymers, drying under vacuum, and finally obtaining grafted particles PAN/SiO2. Subsequently amidoxime-functionalized to PAO/SiO2And (3) resin.
The resin obtained had an organic content of 15% by thermogravimetric analysis and a surface area of 283m
2Per g, pore volume 0.73cm
3Per g, pore size of
Elemental analysis showed C, N and O as 10.98: 1.57: 3.75, the static adsorption capacity to gallium is 3.23 mg/g.
Example 2 PAO/SiO with a degree of crosslinking of 15% and an organic content of 25%2Preparation of
The silica particles were placed in a rotary evaporation flask and pumped to negative pressure using a vacuum pump, then a nitrogen cylinder was connected, nitrogen gas was introduced, and vacuum was applied for 30 minutes. Then a mixture of 33g of monomers (10: 90 mass ratio of DVB and acrylonitrile), 117g of diluent (3: 2 mass ratio of acetophenone and diethyl phthalate) and 0.4g of initiator (azobisisobutyronitrile) was sucked back into the flask. The rotation speed of the rotary evaporator was adjusted to sufficiently mix the mixture with the silica particles. Thereafter, it was slowly heated in a silicon oil bath to 343K for 1 hour, then 353K for 2 hours and finally 363K for 7 hours. Washing the obtained silica grafted acrylonitrile resin with acetone and water respectively to remove physically attached polymers, drying under vacuum, and finally obtaining grafted particles PAN/SiO2. Subsequently amidoxime-functionalized to PAO/SiO2And (3) resin.
Thermogravimetric analysis of the obtained resinThe amount was 20.43%, the surface area was 303m
2Per g, pore volume 0.69cm
3Per g, pore size of
Elemental analysis of C, N, O are 12.55: 1.64: 4.04 and the static adsorption capacity for gallium was 4.40 mg/g.
Example 3
Silica particles of 70 μm were selected as the backbone of the polymer resin. The silica particles were placed in a rotary evaporation flask and pumped to negative pressure using a vacuum pump, then a nitrogen cylinder was connected, nitrogen gas was introduced, and vacuum was applied for 25 minutes. Then a mixture of 90g of monomers (20: 80 mass ratio of DVB and acrylonitrile), 380g of diluent (3: 2 mass ratio of acetophenone and diethyl phthalate) and 0.4g of initiator (azobisisobutyronitrile) was sucked back into the flask, and the rotation speed of the rotary evaporator was adjusted to thoroughly mix the mixture with the silica particles. Thereafter, it was slowly heated in a silicon oil bath to 343K for 0.5h, then 353K for 2.5h and finally 363K for 6.5 h. Washing the obtained silica grafted acrylonitrile resin with acetone and water respectively to remove physically attached polymers, drying under vacuum, and finally obtaining grafted particles PAN/SiO2。
Taking deionized water and ethanol according to the volume ratio of 1:1, mixing; dissolving hydroxylamine hydrochloride in the mixed solution under a nitrogen atmosphere, wherein the mass volume ratio (g/ml) of the hydroxylamine hydrochloride to the deionized water is 5:100, and then adding sodium carbonate under magnetic stirring at room temperature, wherein the mass volume ratio (g/ml) of the sodium carbonate to the deionized water is 5: 100; on the other hand, PAN/SiO2The resin and the mixed solution were charged into a three-necked flask in which PAN/SiO was placed2The mass-to-volume ratio (g/ml) of the resin to the deionized water is 8: 100; a condensation return device is installed, then the system is heated to 343K and is kept in a water bath for 3.5h under nitrogen atmosphere; filtering, washing and drying to finally obtain the synthetic PAO/SiO2And (3) resin.
Example 4
Silica particles of 150 μm were selected as the backbone of the polymer resin. Will be provided withThe silica particles were placed in a rotary evaporation flask and pumped to negative pressure using a vacuum pump, then a nitrogen cylinder was connected, nitrogen gas was introduced, and vacuum was applied for 35 minutes. Then a mixture of 110g of monomers (15: 85 mass ratio of DVB and acrylonitrile), 320g of diluent (3: 2 mass ratio of acetophenone and diethyl phthalate) and 1.5g of initiator (azobisisobutyronitrile) was sucked back into the flask; the rotation speed of the rotary evaporator was adjusted to sufficiently mix the mixture with the silica particles. Thereafter, it was heated slowly in a silicon oil bath to 343K for 1.5h, then 353K for 1.5h and finally 363K for 7.5 h. Washing the obtained silica grafted acrylonitrile resin with acetone and water respectively to remove physically attached polymers, drying under vacuum, and finally obtaining grafted particles PAN/SiO2。
Taking deionized water and ethanol according to the volume ratio of 1:1, mixing; dissolving hydroxylamine hydrochloride in the mixed solution under a nitrogen atmosphere, wherein the mass volume ratio (g/ml) of the hydroxylamine hydrochloride to the deionized water is 10:100, and then adding sodium carbonate under magnetic stirring at room temperature, wherein the mass volume ratio (g/ml) of the sodium carbonate to the deionized water is 3: 100; on the other hand, PAN/SiO2The resin and the mixed solution were charged into a three-necked flask in which PAN/SiO was placed2The mass volume ratio (g/ml) of the resin to the deionized water is 12: 100; a condensation return device is installed, then the system is heated to 343K and is kept in a water bath for 2.5h under nitrogen atmosphere; filtering, washing and drying to finally obtain the synthetic PAO/SiO2And (3) resin.
PAO/SiO of the invention2Compared with commercial resin, firstly, the particle size of the silicon dioxide is 75-150 μm, and the silicon dioxide has larger specific surface area as a framework, and in addition, as a pore-foaming agent is added in the synthesis process, the specific surface area and the porosity of the resin are greatly increased; secondly, because the expansion rate of the commercial resin is large and the expansion rate of the silica as a framework is small, PAO/SiO is generated in the adsorption process2The structure of the resin is not easily destroyed; third, the selective synthesis of PAO/SiO allows for a faster diffusion rate due to reduced mass transfer distances2The resin is more efficient than commercial resins; fourthly, because ofThe gallium adsorption not only occurs on the surface of the resin, but also occurs in the resin, so that the reaction rate can be accelerated only by successfully synthesizing amidoxime groups in the resin, and the effective functional groups are not distributed on the surface of the resin as in the commercial resin.
While the foregoing description shows and describes several preferred embodiments of the invention, it is to be understood, as noted above, that the invention is not limited to the forms disclosed herein, but is not to be construed as excluding other embodiments and is capable of use in various other combinations, modifications, and environments and is capable of changes within the scope of the inventive concept as expressed herein, commensurate with the above teachings, or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.