Acyl quaternary ammonium salt desilicication trapping agent as well as preparation method and application thereof
By introducing alkyl long chain segments and quaternary ammonium salt groups on chitosan segments, acyl quaternary ammonium salt desilica collectors were prepared, which solved the poor flotation effect and biodegradation performance under acidic slurry conditions in the prior art. The problem of insufficient results has achieved efficient, low-cost and environmentally friendly phosphate flotation effect.
Patent Information
- Application Number
- CN202411381318.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2024-12-31
AI Technical Summary
The existing phosphate flotation desilicate collectors show high foam viscosity, poor fluidity, and poor biodegradation performance under acidic slurry conditions, which increases production costs and environmental risks. The market urgently needs a suitable acidic conditions. Low-cost, environmentally friendly acyl quaternary ammonium salt desilicate capture agent.
By introducing alkyl long chain segments and quaternary ammonium salt groups on the chitosan segments, acyl quaternary ammonium salt desilicate collectors are prepared, which have amphiphilic characteristics, high foam stability, and are easy to degrade. Modified chitosan The wettability on the ore is better, improving the flotation effect.
It realizes efficient flotation under acidic conditions, improves flotation effect and foam stability, reduces production costs, and is harmless to the environment, solving the problems of poor fluidity and insufficient biodegradation performance of traditional collectors.
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Abstract
Description
Technical Field
[0001] The invention relates to the field of phosphate rock desiliconization capture agents, and in particular to an acyl quaternary ammonium salt desiliconization capture agent and a preparation method thereof. Background Art
[0002] With the development of the chemical industry, the demand for chemical substances such as yellow phosphorus, phosphoric acid, phosphides and phosphates has increased year by year. Most of these substances come from phosphate rock. Phosphate rock resources are non-renewable resources and occupy an important position in the national economy. China's phosphate rock resources are mainly low-grade calcium-silicon phosphate. Most phosphate ores must be enriched through mineral processing to obtain phosphate concentrate before they can meet the needs of subsequent phosphorus chemical production. At present, desiliconized concentrate is often obtained by flotation with desiliconized collectors.
[0003] The main collectors for phosphate rock flotation desiliconization are amine cationic collectors, and the commonly used collectors are primary amines, tertiary amines, quaternary ammonium, and ether amines. However, amine cationic collectors have the disadvantages of high foam viscosity and poor fluidity, which limits their use in flotation desiliconization. In order to solve this problem, researchers have developed ether amine collectors, which are based on (-O-CH 2 -) polar groups are inserted into fatty amines, making the collector more soluble in water. However, compared with amine cationic collectors, the etheramine collectors have not greatly improved the phenomenon of foam viscosity, and their biodegradability is poor. Usually, these two collectors need to be floated under weakly alkaline pulp conditions in high-silicon magnesium reverse flotation, resulting in the need to adjust the pulp pH in the double reverse flotation process from acidic to alkaline, which increases the cost burden of return water and reagents in the concentrator. Therefore, the development of a reverse flotation agent that is suitable for acidic pulp conditions and has strong collecting performance is of great significance for the efficient utilization of medium and low-grade collophosphate resources.
[0004] Patent CN117380402A discloses a selective flocculant for reverse flotation of collophosphate ore, which is compounded by a composite inorganic polymer flocculant, an aluminum-based flocculant, a synthetic organic polymer flocculant, and a natural organic polymer flocculant. The selective flocculant can improve the problems of poor foam fluidity, sticky foam, and less mineralized foam under the application of cationic collectors. It can not only improve the indicators of phosphate concentrate and reduce the phosphorus grade of tailings, but also simplify the flotation control process and improve the sorting efficiency. However, the flocculant may pose potential risks to the environment, and the flocculant requires multiple steps of synthesis, which will increase the production cost of phosphate ore.
[0005] Patent CN114011580A discloses a method for removing impurities from low-grade fine phosphate ore, which specifically includes the following steps: (1) reverse flotation to remove magnesium; (2) reverse flotation to remove magnesium and silicon simultaneously; and (3) reverse flotation to remove silicon. Compared with the existing forward and reverse treatment processes, this method better avoids the problem of poor flotation effect of the forward and reverse flotation processes under low temperature conditions. The reverse flotation to remove magnesium and silicon can better obtain good flotation indicators under low temperature conditions, and the addition of a flotation adjuster optimizes the foam phenomenon during the reverse flotation to remove silicon and increase the fluidity of the foam. However, this flotation process is relatively complex and has a high cost.
[0006] Therefore, there is an urgent need in the market for an acyl quaternary ammonium salt desiliconization capture agent that is adaptable to acidic conditions, has good flotation effect, is low in cost, and is harmless to the environment. Summary of the invention
[0007] In view of the problems existing in the prior art, the purpose of the present invention is to obtain an acyl quaternary ammonium salt desiliconizing capture agent which is adaptable to acidic conditions, has good flotation effect, has amphiphilic properties, high foam stability, and is easily degradable.
[0008] In order to achieve the above object, the technical solution adopted by the present invention is as follows:
[0009] The first aspect of the present invention provides an acyl quaternary ammonium salt desiliconization capture agent, and the structural formula of the acyl quaternary ammonium salt desiliconization capture agent is as follows:
[0010]
[0011] Among them, R 1 is an alkyl group with a chain length of C6-C18, R 2 for * is a connection site, and n is an integer of 35-55.
[0012] The present application introduces alkyl long chain segments and quaternary ammonium salt groups into chitosan chain segments to prepare acyl quaternary ammonium salt desiliconizing collectors with good hydrophilicity, easy degradation and harmless to the environment. The alkyl long chain segments change the hydrophilic properties of chitosan into amphiphilic properties, so that it has the characteristics and floatability of a surfactant. However, compared with conventional surfactants, the modified chitosan has lower surface tension and better emulsification effect, and can play a better role in foaming and stabilizing foam. In addition, the modified chitosan has better wettability on ore, which can enhance the quaternary ammonium salt groups to be more easily adsorbed on silicate mineral particles through electrostatic action, thereby improving the flotation effect.
[0013] The second aspect of the present invention provides a method for preparing an acyl quaternary ammonium salt desiliconization capture agent, comprising the following steps:
[0014] A1. Add N,N-dimethyldodecylamine, epichlorohydrin and methanol into a reaction vessel, heat to 40-50°C for reaction for 1-3h, wash and dry to obtain compound A;
[0015] A2. Add N-fatty acylated-O-hydroxypropyl chitosan into deionized water, swell at room temperature for 1-2 hours, then heat to 50-60°C and stir for 0.5-1.5 hours, add catalyst and compound A obtained in step A1, react for 6-8 hours, wash and dry to obtain acyl quaternary ammonium salt desiliconization capture agent.
[0016] In some embodiments, the mass ratio of the N-fatty acylated-O-hydroxypropyl chitosan to compound A is 1:(0.2-0.4).
[0017] The present application introduces quaternary ammonium salt groups into N-fatty acylated-O-hydroxypropyl chitosan and selects N-fatty acylated-O-hydroxypropyl chitosan and compound A in a specific ratio, thereby ensuring that the chitosan chain segments contain more quaternary ammonium salt structures on the one hand, and on the other hand, the hydrophobic segments on compound A will not affect the hydrophilicity of chitosan, so that the acyl quaternary ammonium salt desiliconization capture agent has good hydrophilicity and good floatability, thereby improving the flotation effect.
[0018] In some embodiments, the preparation method of N-fatty acylated-O-hydroxypropyl chitosan comprises the following steps: adding fatty acid chloride, hydroxypropyl chitosan, 2,4,6-trimethylpyridine and tetrahydrofuran into deionized water, reacting at 45-55° C. for 1-2 hours, washing and drying to obtain N-fatty acylated-O-hydroxypropyl chitosan.
[0019] Preferably, the fatty acid chloride is one or more of octanoyl chloride, decanoyl chloride, lauroyl chloride, myristoyl chloride and palmitoyl chloride.
[0020] More preferably, the fatty acid chloride is lauroyl chloride.
[0021] Compared with chitosan, hydroxypropyl chitosan has better hydrophilicity, so that the new structure formed by its reaction with fatty acyl chloride still has good hydrophilicity on the basis of containing long-chain alkane segments, which is beneficial to the dispersion of acyl quaternary ammonium salt desiliconization capture agent in water, thereby facilitating the flotation effect of the extraction collector.
[0022] In some embodiments, the mass ratio of the fatty acid chloride to hydroxypropyl chitosan is 1:(3-5).
[0023] After the fatty acid chloride reacts with hydroxypropyl chitosan, an amide group can be introduced into the chitosan, which can increase the hydrogen bonds or dipole moment forces between the molecules of the acyl quaternary ammonium salt desiliconization capture agent, so that the molecules are arranged more closely, thereby increasing the stability of the foam layer, and making the acyl quaternary ammonium salt desiliconization capture agent have a better flotation effect. However, the amino content on the chitosan affects the degradability of the chitosan. The present application can introduce alkane segments into the chitosan by selecting a specific ratio of fatty acid chloride and the amino reaction on the hydroxypropyl chitosan, while not reducing the degradability of the chitosan. This may be because the amide bond has good hydrophilicity and degradability.
[0024] In some embodiments, the mass ratio of water, 2,4,6-trimethylpyridine and tetrahydrofuran is (2-3):(1-2):1.
[0025] The present application prepares the solvent by selecting a specific ratio of water, pyridine and tetrahydrofuran, so that hydroxypropyl chitosan can be well dissolved in the water phase, and fatty acid chloride can be well dissolved in the tetrahydrofuran phase. 2,4,6-trimethylpyridine reacts with the hydrochloric acid generated in the synthesis process to form pyridine hydrochloride to catalyze the reaction, thereby improving the yield of N-fatty acylated-O-hydroxypropyl chitosan.
[0026] The third aspect of the present invention provides an application of an acyl quaternary ammonium salt desiliconization capture agent, comprising the following steps: weighing a mineral sample and placing it in a flotation tank, adding water, slurrying at a rotation speed of 1600-1900 r / min for 1-5 min, adjusting the pH value to 4-5, continuing to stir for 1-3 min, then adding an acyl quaternary ammonium salt desiliconization capture agent solution and an inhibitor, stirring for another 3-5 min, opening an air inlet, controlling the ventilation volume to 1.5-2.5 L / min, scraping off foam and collecting materials at the bottom of the flotation tank, and obtaining a desiliconized concentrate after drying.
[0027] In some embodiments, the method for preparing the solution of the acyl quaternary ammonium salt desiliconizing capture agent comprises the following steps: adding the acyl quaternary ammonium salt desiliconizing capture agent into deionized water, swelling it at room temperature for 1-2 hours, then heating it to 50-60° C. and stirring it for 0.5-1.5 hours to obtain the solution.
[0028] In some embodiments, the mass ratio of water to mineral sample is 1:(0.15-0.25).
[0029] In some embodiments, the usage of the acyl quaternary ammonium salt desiliconization capture agent is 1-2 kg / t.
[0030] Compared with the prior art, the present invention has the following beneficial effects:
[0031] (1) The present invention introduces alkyl long chain segments and quaternary ammonium salt groups into chitosan chain segments to prepare acyl quaternary ammonium salt desiliconizing collectors, which have amphiphilic properties, are easily degraded and harmless to the environment, have good foaming and foam stabilizing effects, and the modified chitosan has better wettability on the ore, which can make the quaternary ammonium salt groups more easily adsorbed on silicate mineral particles through electrostatic action, thereby improving the flotation effect.
[0032] (2) The present invention introduces quaternary ammonium salt groups into N-fatty acylated-O-hydroxypropyl chitosan, which can ensure that the chitosan chain segments contain more quaternary ammonium salt structures on the one hand, and on the other hand, the introduced alkyl segments will not affect the hydrophilicity of chitosan, so that the acyl quaternary ammonium salt desiliconizing capture agent has good hydrophilicity and good floatability, thereby improving the flotation effect.
[0033] (3) The new structure formed by the reaction of the hydroxypropyl chitosan with good hydrophilicity and fatty acid chloride in the present invention still has good hydrophilicity on the basis of containing long-chain alkane segments, and the amide group can be introduced into the chitosan after the reaction of fatty acid chloride and hydroxypropyl chitosan, which can increase the hydrogen bond or dipole moment between the molecules of each acyl quaternary ammonium salt desiliconization capture agent, so that the molecules are arranged more closely, thereby increasing the stability of the foam layer and further improving the flotation effect of the acyl quaternary ammonium salt desiliconization capture agent. In addition, the amide bond has good hydrophilicity, which can improve the degradability of the acyl quaternary ammonium salt desiliconization capture agent. DETAILED DESCRIPTION
[0034] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following embodiments are examples of the present invention and are only used to illustrate the present invention, but not to limit the present invention. Other combinations and various modifications within the concept of the present invention may be performed without departing from the spirit or scope of the present invention.
[0035] In the following examples and comparative examples, the compounds and related reagents used can be purchased from the market. Among them, the deacetylation degree of hydroxypropyl chitosan is 85%, purchased from Wuhan Smack Biotechnology Co., Ltd.; the model of the defoamer is AFE-3168, purchased from Shenzhen Dayang New Materials Co., Ltd.; the model of the inhibitor is HQD82, purchased from Hunan Huaqi Resources and Environment Technology Development Co., Ltd.
[0036] Preparation Example 1
[0037] The preparation method of N-fatty acylated-O-hydroxypropyl chitosan-1 comprises the following steps: adding 1g of lauroyl chloride, 4g of hydroxypropyl chitosan, 3g of 2,4,6-trimethylpyridine and 2g of tetrahydrofuran into 5g of deionized water, reacting at 50°C for 1.5h, washing and drying to obtain N-fatty acylated-O-hydroxypropyl chitosan-1.
[0038] Preparation Example 2
[0039] The preparation method of N-fatty acylated-O-hydroxypropyl chitosan-2 is the same as that of Preparation Example 1, except that the added amount of hydroxypropyl chitosan is 2 g.
[0040] Preparation Example 3
[0041] The preparation method of N-fatty acylated-O-hydroxypropyl chitosan-3 is the same as that of Preparation Example 1, except that the added amount of 2,4,6-trimethylpyridine is 1.5 g.
[0042] Example 1
[0043] A method for preparing an acyl quaternary ammonium salt desiliconizing capture agent comprises the following steps:
[0044] A1, add 9.5g N,N-dimethyldodecylamine, 5g epichlorohydrin and 5ml anhydrous methanol into a reaction container, heat to 45°C for 2h, wash and dry to obtain compound A;
[0045] A2, add 10g N-fatty acylated-O-hydroxypropyl chitosan-1 to 20g deionized water, swell at room temperature for 1.5h, then heat to 55°C and stir for 1h, add 1g pyridine and 3g compound A obtained in step A1, react for 7h, wash and dry to obtain an acyl quaternary ammonium salt desiliconization capture agent, wherein the structural formula of the acyl quaternary ammonium salt desiliconization capture agent is as follows:
[0046]
[0047] Wherein, * is the connection site and n is 46.
[0048] Example 2
[0049] A method for preparing an acyl quaternary ammonium salt desiliconizing capture agent comprises the following steps:
[0050] A1. Add 9.5 g of N,N-dimethyldodecylamine, 5 g of epichlorohydrin and 5 ml of methanol into a reaction vessel, heat to 40° C. and react for 3 h, then wash and dry to obtain compound A;
[0051] A2, add 10g N-fatty acylated-O-hydroxypropyl chitosan-1 to 20g deionized water, swell at room temperature for 1h, then heat to 50°C and stir for 1.5h, add 1g pyridine and 2g compound A obtained in step A1, react for 6h, wash and dry to obtain an acyl quaternary ammonium salt desiliconization capture agent, wherein the structural formula of the acyl quaternary ammonium salt desiliconization capture agent is as follows:
[0052]
[0053] Wherein, * is the connection site and n is 37.
[0054] Example 3
[0055] A method for preparing an acyl quaternary ammonium salt desiliconizing capture agent comprises the following steps:
[0056] A1, add 9.5g N,N-dimethyldodecylamine, 5g epichlorohydrin and 5ml methanol into a reaction container, heat to 50°C for 1h, wash and dry to obtain compound A;
[0057] A2, add 10g N-fatty acylated-O-hydroxypropyl chitosan-1 to 20g deionized water, swell at room temperature for 2h, then heat to 60°C and stir for 0.5h, add 1g pyridine and 4g compound A obtained in step A1, react for 8h, wash and dry to obtain an acyl quaternary ammonium salt desiliconization capture agent, wherein the structural formula of the acyl quaternary ammonium salt desiliconization capture agent is as follows:
[0058]
[0059] Wherein, * is the connection site and n is 54.
[0060] Example 4
[0061] A method for preparing an acyl quaternary ammonium salt desiliconizing capture agent, the specific implementation method is the same as that of Example 1, except that the added amount of compound A is 1 g.
[0062] Example 5
[0063] A method for preparing an acyl quaternary ammonium salt desiliconizing capture agent, the specific implementation method is the same as that of Example 1, except that the added amount of compound A is 5g.
[0064] Example 6
[0065] A method for preparing an acyl quaternary ammonium salt desiliconizing capture agent, the specific implementation method is the same as that of Example 1, except that an equal amount of N-fatty acylated-O-hydroxypropyl chitosan-1 is replaced by N-fatty acylated-O-hydroxypropyl chitosan-2.
[0066] Example 7
[0067] A method for preparing an acyl quaternary ammonium salt desiliconizing capture agent, the specific implementation method is the same as that of Example 1, except that an equal amount of N-fatty acylated-O-hydroxypropyl chitosan-1 is replaced by N-fatty acylated-O-hydroxypropyl chitosan-3.
[0068] Comparative Example 1
[0069] A method for preparing an acyl quaternary ammonium salt desiliconizing capture agent comprises the following steps:
[0070] A1. Add 9.5 g of N,N-dimethyldodecylamine, 5 g of epichlorohydrin and 5 ml of methanol into a reaction vessel, heat to 45° C. and react for 2 h, then wash and dry to obtain compound A;
[0071] A2, add 10g N-fatty acylated-O-hydroxypropyl chitosan-1 to 20g deionized water, swell at room temperature for 1.5h, then heat to 55°C and stir for 1h, add 1g pyridine and 3g compound A obtained in step A1, react for 4h, wash and dry to obtain an acyl quaternary ammonium salt desiliconization capture agent, wherein the structural formula of the acyl quaternary ammonium salt desiliconization capture agent is as follows:
[0072]
[0073] Wherein, * is the connection site and n is 22.
[0074] Comparative Example 2
[0075] A method for preparing an acyl quaternary ammonium salt desiliconizing capture agent comprises the following steps:
[0076] A1. Add 9.5 g of N,N-dimethyldodecylamine, 5 g of epichlorohydrin and 5 ml of methanol into a reaction vessel, heat to 45° C. and react for 2 h, then wash and dry to obtain compound A;
[0077] A2, add 10g N-fatty acylated-O-hydroxypropyl chitosan-1 to 20g deionized water, swell at room temperature for 1.5h, then heat to 55°C and stir for 1h, add 1g pyridine and 3g compound A obtained in step A1, react for 9h, wash and dry to obtain an acyl quaternary ammonium salt desiliconization capture agent, wherein the structural formula of the acyl quaternary ammonium salt desiliconization capture agent is as follows:
[0078]
[0079] Wherein, * is the connection site and n is 65.
[0080] Performance Testing
[0081] (1) Sample preparation
[0082] The acyl quaternary ammonium salt desiliconizing capture agent obtained in the above-mentioned embodiments and comparative examples was used to carry out a flotation experiment on a low-grade calcareous silicate colloid phosphate ore provided by a phosphate mining company in Hubei. The elemental analysis of the low-grade calcareous silicate colloid phosphate ore is shown in Table 1:
[0083] Table 1
[0084] Components <![CDATA[P 2 THE 5 ]]> MgO <![CDATA[SiO 2 ]]> CaO <![CDATA[Fe 2 THE 3 ]]> <![CDATA[Al 2 THE 3 ]]> other Mass fraction % 25.84 2.15 16.37 43.65 1.97 4.39 5.63
[0085] The flotation experiment consists of the following steps:
[0086] B1. Add 1.5 g of acyl quaternary ammonium salt desiliconizing capture agent into 4 g of deionized water, swell at room temperature for 1.5 h, then heat to 55° C. and stir for 1 h to obtain an acyl quaternary ammonium salt desiliconizing capture agent solution.
[0087] B2. Weigh 100 g of low-grade calci-silicon colloid phosphate and place it in a flotation tank, add 500 g of distilled water, turn on the stirring switch, adjust the slurry at a speed of 1800 r / min for 3 min, add 85 wt % phosphoric acid to adjust the pH value to 5, continue stirring for 2 min, add 4 g of acyl quaternary ammonium salt desiliconization capture agent solution and 0.1 g of inhibitor HQD82 obtained in step B1, stir for another 4 min, open the air inlet, control the ventilation volume to 2 L / min, scrape off the foam and collect the material at the bottom of the flotation tank, obtain the desiliconized concentrate after drying, and collect the foam.
[0088] (2) Performance test: 0.1 g of defoamer AFE-3168 was added to 10 g of the collected foam for defoaming, filtration, and drying to obtain phosphate tailings. The phosphate concentrate and phosphate tailings after flotation were filtered, dried, weighed, and sampled. The contents of silicon and phosphorus were measured using an XRF instrument, and then the phosphorus pentoxide content and silicon dioxide content were calculated to calculate the concentrate P 2 O 5 Grade, P 2 O 5 The flotation effect is determined by the recovery rate and desiliconization rate.
[0089] The test results are shown in Table 1:
[0090] Table 1
[0091] Group <![CDATA[Concentrate P 2 O 5 Grade %]]> <![CDATA[P 2 O 5 Recovery rate %]]> Desiliconization rate % Example 1 32.7 82.2 76.5 Example 2 31.9 81.9 75.3 Example 3 32.3 82.4 75.5 Example 4 30.4 78.3 67.2 Example 5 30.7 78.8 65.3 Example 6 29.2 77.7 61.4 Example 7 28.9 76.9 63.7 Comparative Example 1 27.7 75.7 55.5 Comparative Example 2 27.3 74.5 52.3
[0092] It can be seen from the data in Table 1 that the acyl quaternary ammonium salt desiliconization capture agent in Examples 1-3 of the present invention has a good flotation effect. From the comparison between Examples 4 and 5 and Example 1, it can be seen that changing the ratio of compound A will affect the content of the quaternary ammonium salt structure of the acyl quaternary ammonium salt desiliconization capture agent and the hydrophilicity of N-fatty acylated-O-hydroxypropyl chitosan, thereby making the flotation effect of the acyl quaternary ammonium salt desiliconization capture agent worse; from the comparison between Example 6 and Example 1, it can be seen that changing the ratio of hydroxypropyl chitosan will make the amide groups on N-fatty acylated-O-hydroxypropyl chitosan insufficient to be arranged more closely between the layers through hydrogen bonding, making the foam layer stable. The flotation effect of the acyl quaternary ammonium salt desiliconization capture agent is reduced; from the comparison between Example 7 and Example 1, it can be seen that changing the ratio of 2,4,6-trimethylpyridine will reduce the grafting rate of the alkyl chain end of N-fatty acylated-O-hydroxypropyl chitosan, thereby reducing the floatability of the acyl quaternary ammonium salt desiliconization capture agent, and further deteriorating the flotation effect of the acyl quaternary ammonium salt desiliconization capture agent; from the comparison between Comparative Examples 1 and 2 and Example 1, it can be seen that changing the chain segment length of the acyl quaternary ammonium salt desiliconization capture agent will affect the hydrophilicity and floatability of the acyl quaternary ammonium salt desiliconization capture agent, and deteriorate the flotation effect of the acyl quaternary ammonium salt desiliconization capture agent.
[0093] The above implementation modes are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.
Claims
1. An acyl quaternary ammonium salt desiliconization capture agent, characterized in that: The structural formula of the acyl quaternary ammonium salt desiliconization capture agent is as follows: Wherein, R1 is an alkyl group with a chain length of C6-C18, and R2 is * is a connection site, and n is an integer of 35-55.
2. A method for preparing the acyl quaternary ammonium salt desiliconizing capture agent according to claim 1, characterized in that: The following steps are involved: A1. Add N,N-dimethyldodecylamine, epichlorohydrin and methanol into a reaction vessel, heat to 40-50°C for reaction for 1-3h, wash and dry to obtain compound A; A2. Add N-fatty acylated-O-hydroxypropyl chitosan into deionized water, swell at room temperature for 1-2 hours, then heat to 50-60°C and stir for 0.5-1.5 hours, add catalyst and compound A obtained in step A1, react for 6-8 hours, wash and dry to obtain acyl quaternary ammonium salt desiliconization capture agent.
3. The method for preparing the acyl quaternary ammonium salt desiliconizing capture agent according to claim 2, characterized in that: The mass ratio of the N-fatty acylated-O-hydroxypropyl chitosan to compound A is 1:(0.2-0.4).
4. The method for preparing the acyl quaternary ammonium salt desiliconizing capture agent according to claim 2, characterized in that: The preparation method of N-fatty acylated-O-hydroxypropyl chitosan comprises the following steps: adding fatty acid chloride, hydroxypropyl chitosan, pyridine and tetrahydrofuran into deionized water, reacting at 45-55° C. for 1-2 hours, washing and drying to obtain N-fatty acylated-O-hydroxypropyl chitosan.
5. The method for preparing the acyl quaternary ammonium salt desiliconizing capture agent according to claim 4, characterized in that: The mass ratio of the fatty acid chloride to hydroxypropyl chitosan is 1:(3-5).
6. The method for preparing the acyl quaternary ammonium salt desiliconizing capture agent according to claim 4, characterized in that: The mass ratio of the deionized water, pyridine and tetrahydrofuran is (2-3):(1-2):
1.
7. Use of the acyl quaternary ammonium salt desiliconization capture agent according to claim 1 or the acyl quaternary ammonium salt desiliconization capture agent obtained by any one of the preparation methods of claims 2 to 6, characterized in that: The method comprises the following steps: weighing a mineral sample and placing it in a flotation tank, adding water, slurrying at a rotation speed of 1600-1900 r / min for 1-5 minutes, adjusting the pH value to 4-5, adding an acyl quaternary ammonium salt desiliconization capture agent solution and an inhibitor after continuing stirring for 1-3 minutes, stirring for another 3-5 minutes, opening an air inlet, controlling the ventilation volume to 1.5-2.5 L / min, scraping off foam, collecting materials at the bottom of the flotation tank, and obtaining desiliconized concentrate after drying.
8. The use of the acyl quaternary ammonium salt desiliconization capture agent according to claim 7, characterized in that: The method for preparing the acyl quaternary ammonium salt desiliconizing capture agent solution comprises the following steps: adding the acyl quaternary ammonium salt desiliconizing capture agent into deionized water, swelling it at room temperature for 1-2 hours, then heating it to 50-60° C. and stirring it for 0.5-1.5 hours to obtain the solution.
9. The use of the acyl quaternary ammonium salt desiliconizing capture agent according to claim 7, characterized in that: The mass ratio of the water to the mineral sample is 1:(0.15-0.25).
10. The use of the acyl quaternary ammonium salt desiliconizing capture agent according to claim 7, characterized in that: The usage of the acyl quaternary ammonium salt desiliconizing capture agent is 1-2 kg / t.