Preparation method and application of a composite quaternary ammonium salt cationic collector

Abstract

The application relates to the technical field of ore dressing reagent preparation, in particular to a preparation method and application of a composite quaternary ammonium salt cationic collector; the method comprises the following steps: adding a halogenated alkyl to an alkyl tertiary amine containing an amide group to perform a quaternary ammonium reaction, so as to obtain an intermediate; adding a catalyst to the intermediate to perform a catalytic reaction, then adding a benzyloxyamine hydrochloride to perform an amidation reaction, and performing desalination treatment, so as to obtain the composite quaternary ammonium salt cationic collector; the molar ratio of the alkyl tertiary amine, the halogenated alkyl and the benzyloxyamine hydrochloride is 1-1.4:0.8-1.2:1-1.4; the preparation method only needs three reaction steps in the whole synthesis process, and the reaction condition is mild, so that the composite quaternary ammonium salt cationic collector can be synthesized more simply and at a low cost, and the collector has the characteristics of high flotation efficiency and environmental friendliness.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ore dressing reagent preparation, and particularly relates to a preparation method of a composite quaternary ammonium salt cationic collector and application thereof. BACKGROUND

[0002] At present, bauxite in China mainly includes kaolinite and illite type bauxite, and the commonly used cationic collector in the reverse flotation desilication of bauxite is mainly amine type cationic collector. The commonly used amine type cationic collector mainly includes dodecylamine, dodecyltrimethyl quaternary ammonium salt and dodecyl dimethyl benzyl quaternary ammonium salt, wherein the quaternary ammonium salt type collector is mainly studied, and the quaternary ammonium salt type compound is mainly alkyl quaternary ammonium salt. The dodecyltrimethyl ammonium chloride in the alkyl quaternary ammonium salt has better effect on the reverse flotation desilication of bauxite than dodecylamine. Research shows that the effect of dodecyltrimethyl ammonium chloride on aluminosilicate minerals is mainly electrostatic effect.

[0003] At present, the application of cationic collectors in the flotation of potassium salt ore and lepidolite ore or the reverse flotation desilication and impurity removal of iron ore and bauxite has respective characteristics, but still has certain deficiencies, mainly including poor biodegradability of the collector, easy pollution to the environment, sensitivity to slime, poor selectivity, and much lower flotation efficiency than positive flotation desilication. The existing cationic collectors are mainly dodecylamine or other long carbon chain aliphatic amines. Although many years of research has developed polyamine, polyether amine, tertiary amine, quaternary ammonium salt, alkyl guanidine and the like, which greatly promotes the development of cationic collectors, the development of the reverse flotation desilication process is still relatively slow. Moreover, the existing collectors have the disadvantages of inconvenient reagent preparation, large foam viscosity and poor selectivity in the flotation process.

[0004] At present, the research on cationic collectors mainly focuses on ether amine and quaternary ammonium salt, and these directions still have the disadvantages of synthesis difficulty and high cost, which seriously hinders the popularization and application of bauxite reverse flotation. Therefore, how to provide a simple and efficient synthesis method of cationic collector to perfect the reverse flotation desilication process is a technical problem to be solved at present. SUMMARY

[0005] The present application provides a preparation method of a composite quaternary ammonium salt cationic collector and application thereof, so as to solve the technical problems of synthesis difficulty and high cost of the cationic collector for reverse flotation desilication in the prior art.

[0006] In a first aspect, the present application provides a preparation method of a composite quaternary ammonium salt cationic collector, which comprises the following steps:

[0007] adding a halogenated alkyl to the alkyl tertiary amine containing an amide group to perform quaternary ammonium reaction to obtain an intermediate;

[0008] The intermediate is added with a catalyst for catalytic reaction, then added with benzylamine hydrochloride for amidation reaction, and desalted to obtain the complex quaternary ammonium salt cationic collector;

[0009] The molar ratio of the alkyl tertiary amine, the haloalkyl and the benzylamine hydrochloride is 1-1.4:0.8-1.2:1-1.4.

[0010] Optionally, the alkyl tertiary amine is an alkyl tertiary amine with a carbon chain length of 12-18.

[0011] Optionally, the alkyl tertiary amine includes lauryl amide propyl dimethyl tertiary amine and / or octadecanamide propyl dimethyl amine tertiary amine; and / or,

[0012] The haloalkyl includes sodium chloroacetate and / or sodium bromoacetate; and / or,

[0013] Optionally, the temperature of the quaternary ammonium reaction is 30-55°C, and the time of the quaternary ammonium reaction is 18-24h.

[0014] Optionally, the temperature of the amidation reaction is 3-10°C, and the time of the amidation reaction is 22-26h.

[0015] Optionally, the haloalkyl is added to the alkyl tertiary amine containing amide group for quaternary ammonium reaction to obtain the intermediate, including the steps of:

[0016] The haloalkyl is added dropwise to the alkyl tertiary amine containing amide group for quaternary ammonium reaction to obtain the intermediate precursor;

[0017] The pH of the intermediate precursor is adjusted, and then condensed and extracted, and then evaporated and dried with a drying agent and vacuum distillation purification to obtain the intermediate containing quaternary ammonium group and carboxylic acid group.

[0018] Optionally, the time of the first stirring is 10-20min; and / or,

[0019] The temperature of the second stirring is 35-45°C, and the time of the second stirring is 19-22h.

[0020] Optionally, the catalyst is added to the intermediate for catalytic reaction, then the benzylamine hydrochloride is added for amidation reaction, and desalted to obtain the complex quaternary ammonium salt cationic collector, including the steps of:

[0021] The intermediate is added to a solution of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysulfosuccinimide, and the pH is adjusted to a preset pH using a MES solution, then benzylamine hydrochloride is added to perform an amidation reaction, and desalination treatment is performed to obtain the complex quaternary ammonium salt cationic collector;

[0022] The preset pH is 5.0-5.5.

[0023] Optionally, the complex quaternary ammonium salt cationic collector has a structural formula as shown in Formula 1:

[0024]

[0025] Formula 1;

[0026] The R1 group includes a linear alkyl group; and X includes Cl or Br.

[0027] The linear alkyl group has a carbon chain length of 11-17.

[0028] In a second aspect, the application provides an application of the preparation method of the complex quaternary ammonium salt cationic collector, and the application includes using the complex quaternary ammonium salt cationic collector obtained by the preparation method in the first aspect in desilication of bauxite reverse flotation.

[0029] Compared with the prior art, the above technical solution provided in the embodiments of the application has the following advantages:

[0030] The preparation method of the complex quaternary ammonium salt cationic collector provided in the embodiments of the application generates an intermediate with a quaternary ammonium group and a carboxylic acid group by performing a quaternary ammonium reaction on an alkyl tertiary amine and a halogenated alkyl group, then performs a catalytic reaction on the intermediate using a catalyst, and then performs an amidation reaction by adding benzylamine hydrochloride, so that the carboxylic acid group reacts with the benzylamine hydrochloride to generate an amide group under the condition of the catalyst, and a benzyl group is obtained at the same time, and then a complex quaternary ammonium salt cationic collector containing a quaternary ammonium group, an amide group, a linear alkyl group and a benzyl group is obtained. The cationic collector has good hydrophobicity due to the linear alkyl group, and the quaternary ammonium group can be adsorbed on the surface of mineral particles by electrostatic interaction with the surface of siliceous mineral particles, so as to float the siliceous mineral particles. Moreover, the quaternary ammonium group can be used for flotation of silicate minerals under acidic mineral slurry, and the amide group is more easily degraded and has better hydrophilicity, so the cationic collector is more friendly to the environment and people in terminal application. Moreover, the benzyl group in the molecule has hydrophobicity, so the flotation separation of oxidized minerals and salt minerals can be strengthened, the foam performance is improved, and the desilication selectivity is improved, and the cationic collector has the characteristics of high flotation efficiency and environmental friendliness. Since the overall synthesis process only needs three reaction steps and the reaction conditions are mild, the cationic collector can be synthesized more simply and at low cost. Attached Figure Description

[0031] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0032] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A schematic diagram of the preparation method of the composite quaternary ammonium salt cationic collector provided in the embodiments of this application;

[0034] Figure 2 A detailed flowchart illustrating the preparation method of the composite quaternary ammonium salt cationic collector provided in the embodiments of this application;

[0035] Figure 3 A schematic diagram illustrating the principle of the preparation method of the composite quaternary ammonium salt cationic collector provided in the embodiments of this application;

[0036] Figure 4 A flowchart illustrating the desilication process of pure mineral flotation using a composite quaternary ammonium salt cationic collector provided in this application embodiment;

[0037] Figure 5 Flowchart of the composite quaternary ammonium salt cationic collector in bauxite flotation desilication open-circuit process provided in the embodiments of this application;

[0038] Figure 6 A closed-loop process diagram of the composite quaternary ammonium salt cationic collector used in bauxite flotation desilication, as provided in the embodiments of this application. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0041] The creative thinking employed in this application is as follows:

[0042] The current application direction of cationic collectors mainly includes:

[0043] (1) Patent CN102259062A discloses the preparation method of organic silicon quaternary ammonium salt compound, and its application in the flotation separation of potassium chloride and sodium chloride and the reverse flotation desilication and impurity removal of iron ore and bauxite.

[0044] (2) Patent CN101337204 discloses the application of double quaternary ammonium salt compound as a flotation collector in the reverse flotation desilication of bauxite and iron ore.

[0045] (3) Patent CN107442287A discloses the application of a gemini surfactant in the reverse flotation desilication and impurity removal of potassium salt ore, lepidolite ore or iron ore and bauxite.

[0046] (4) Patent CN1507954A discloses a collector for reverse flotation desilication and its preparation method. The collector belongs to a composite quaternary ammonium salt cationic surfactant, contains quaternary ammonium group and / or benzyl-containing quaternary ammonium salt compound, and is suitable for reverse flotation separation of silicate minerals from iron ore such as magnetite, hematite and ilmenite, and bauxite and other silicate-containing minerals.

[0047] (5) Patent CN106238215A discloses a quaternary ammonium salt cationic collector and its synthesis method. A double quaternary ammonium salt is synthesized by a two-step method, mainly used for reverse flotation desilication of collophanite.

[0048] (6) Patent CN112657681A discloses a cationic collector and its preparation method and application, which is used for desilication of iron ore, desilication of magnesite, desilication of phosphate rock, flotation of feldspar, adaptive flotation or silicate flotation.

[0049] (7) Patent CN112474061A discloses the preparation and application of a quaternary ammonium salt cationic collector containing ester group for reverse flotation of phosphate rock. The collector contains an ester group, which makes the collector have good degradation effect, contains a long carbon chain and a quaternary ammonium group, but the dosage is too large in phosphate rock flotation, the cost is high, in addition, the raw material N,N-dimethylethanolamine is a controlled product, which is flammable and toxic.

[0050] (8) Patent CN107716116A discloses a preparation method of an iron ore reverse flotation collector and its application.

[0051] (9) Patent CN110605183A discloses a phosphate ore reverse flotation desilication aluminum collector and its preparation method and application, the collector contains mixed amine, mixed alcohol and methyl cocoate. Patent CN110038728A discloses a method for reverse flotation of hematite using high-degradability amine collector, the collector used is lauryl amide propyl dimethyl amine oxide. CN109847944A discloses a preparation method of N-(2-hydroxy-1,1-dimethylethyl) alkyl amine, which is suitable for the field of iron ore reverse flotation.

[0052] (10) CN103769307B discloses a collector with good water solubility, containing a tertiary amine with two hydroxypropyl groups, which is used for iron ore flotation. This collector has good water solubility, but weak collecting ability and is not easy to form bubbles.

[0053] (11) CN107350084A discloses a kind of three quaternary ammonium salt compounds for mineral flotation, which has three mineralophilic groups and is used for the flotation of phosphate ore, iron ore and other minerals.

[0054] (12) CN113751207A discloses a collector and its preparation method and application. The prepared hydrophobic nanoparticle collector is used for desulfurization collection in the reverse flotation of fine particle high-sulfur bauxite, and belongs to a desulfurization collector.

[0055] (13) CN113769896A discloses a collector and its preparation method and application. The prepared collector mainly collects aluminum minerals in bauxite and belongs to a positive flotation desilication collector, which is different from the reverse flotation desilication collector of the present application.

[0056] The above-mentioned prior art has its own characteristics in the application of potassium salt mine, lithium mica ore flotation or iron ore, bauxite reverse flotation desilication, but still has some shortcomings, mainly manifested as poor biodegradability of the collector, easy to pollute the environment; sensitive to slime, poor selectivity; the flotation efficiency is much lower than that of positive flotation desilication. The existing cationic collectors are mainly dodecylamine or other long-chain aliphatic amines. Although many years of research has developed polyamine, polyether amine, tertiary amine, quaternary ammonium salt, alkyl guanidine, etc., which has greatly promoted the development of cationic collectors, but the development of reverse flotation desilication process is still relatively slow, and the existing collectors have the disadvantages of inconvenient reagent preparation, high foam viscosity and poor selectivity in the flotation process.

[0057] At present, the research on cationic collectors mainly focuses on ether amine and quaternary ammonium salt, but these directions still have the disadvantages of synthesis difficulty and high cost, which seriously hinders the popularization and application of bauxite reverse flotation. Therefore, how to provide a simple and efficient synthesis method of cationic collector to perfect the cationic reverse flotation desilication process is a technical problem to be solved at present.

[0058] like Figure 1 As shown in the embodiments of this application, a method for preparing a composite quaternary ammonium salt cationic collector is provided, the method comprising:

[0059] S1. Add a haloalkyl group to an alkyl tertiary amine containing an amide group to carry out a quaternization reaction to obtain an intermediate containing an amide group;

[0060] S2. A catalyst is added to the intermediate to carry out a catalytic reaction, followed by the addition of benzyloxyamine hydrochloride to carry out an amidation reaction, and then desalting treatment is performed to obtain a composite quaternary ammonium salt cationic collector containing two amide groups;

[0061] The molar ratio of the alkyl tertiary amine, the haloalkyl group, and the benzyloxyamine hydrochloride is 1–1.4:0.8–1.2:1–1.4.

[0062] In the embodiments of this application, controlling the specific molar ratio of alkyl tertiary amine, haloalkyl and benzyloxyamine hydrochloride can ensure the quaternization reaction is complete, thereby making the intermediate contain quaternary ammonium group and carboxylic acid group, and at the same time, it can also form amide group in the subsequent amidation reaction, thereby obtaining a composite quaternary ammonium salt cationic collector containing quaternary ammonium group, amide group, straight-chain alkane group and benzyl group.

[0063] The preparation method of this application is based on the following principle: Figure 3 As shown, R1 group represents a straight-chain alkane with a chain length of 11 to 17, and X is Cl or Br.

[0064] In some alternative embodiments, the alkyl tertiary amine is an alkyl tertiary amine with a carbon chain length of 12 to 18.

[0065] In the embodiments of this application, controlling the specific carbon chain length of the alkyl tertiary amine can result in the presence of long-chain alkane groups in the composite quaternary ammonium salt cationic collector. Since long-chain alkane groups are hydrophobic, the hydrophobicity of the composite quaternary ammonium salt cationic collector can be improved, facilitating the smooth progress of the collection process.

[0066] In some alternative embodiments, the alkyl tertiary amine comprises lauramidopropyl dimethyl tertiary amine and / or octadecamidopropyl dimethylamine tertiary amine; and / or,

[0067] The haloalkyl group includes sodium chloroacetate and / or sodium bromoacetate; and / or,

[0068] In the embodiments of this application, specific alkyl tertiary amines, haloalkyl groups, and benzyloxyamine hydrochlorides are controlled, thereby enabling the simple synthesis of composite quaternary ammonium salt cationic collectors containing quaternary ammonium groups, amide groups, straight-chain alkane groups, and benzyl groups.

[0069] In some alternative embodiments, the temperature of the quaternary ammoniation reaction is 30-55°C, and the time of the quaternary ammoniation reaction is 18-24 hours.

[0070] In the embodiments of the present application, the temperature and time of the specific quaternary ammoniation reaction are controlled to allow the alkyl tertiary amine and the haloalkyl to fully react, and to obtain the intermediate containing the quaternary ammonium group and the carboxylic acid group.

[0071] In some alternative embodiments, the temperature of the amidation reaction is 3-10°C, and the time of the amidation reaction is 22-26 hours.

[0072] In the embodiments of the present application, the temperature and time of the specific amidation reaction are controlled to allow the intermediate after the catalytic reaction to react with the benzyl alcohol amine hydrochloride and the intermediate to form the amide group, thereby obtaining the complex quaternary ammonium salt cationic collector containing the quaternary ammonium group, the amide group, the linear alkyl group and the benzyl group.

[0073] In some alternative embodiments, the quaternary ammoniation reaction is performed by adding the haloalkyl to the alkyl tertiary amine containing the amide group, and the intermediate is obtained, including the steps of:

[0074] S101. The solvent is added to the alkyl tertiary amine containing the amide group for first stirring, then the haloalkyl is added dropwise, and second stirring is performed to perform the quaternary ammoniation reaction, thereby obtaining the intermediate precursor;

[0075] S102. The pH of the intermediate precursor is adjusted, and condensation and extraction are performed, then the drying agent is used for evaporation drying and vacuum distillation purification, thereby obtaining the intermediate containing the quaternary ammonium group and the carboxylic acid group.

[0076] In the embodiments of the present application, the alkyl tertiary amine is first dispersed by stirring in the solvent, to form the alkyl tertiary amine solution, then the haloalkyl is added, and second stirring is performed, to allow the quaternary ammoniation reaction between the haloalkyl and the alkyl tertiary amine, thereby obtaining the intermediate containing the quaternary ammonium group and the carboxylic acid group, and the intermediate is further subjected to the subsequent pH adjustment, condensation and extraction, and evaporation drying and vacuum distillation purification, to further improve the purity of the intermediate.

[0077] The solvent can be anhydrous ethanol.

[0078] The drying agent can be sodium sulfate.

[0079] The extraction reagent can be acetone.

[0080] In some alternative embodiments, the time of the first stirring is 10-20 minutes; and / or,

[0081] The second stirring temperature is 35-45℃, and the second stirring time is 19-22h.

[0082] In the embodiments, the first stirring time, the second stirring temperature and the second stirring time are controlled, so that the alkyl tertiary amine is fully dispersed in the solvent through the first stirring, and the quaternary ammonium reaction between the halogenated alkyl and the alkyl tertiary amine is caused and completed through the second stirring, so that the intermediate is obtained.

[0083] In some optional embodiments, the intermediate is added with a catalyst to perform a catalytic reaction, then added with a benzyloxyamine hydrochloride to perform an amidation reaction, and then subjected to a desalting treatment to obtain the composite quaternary ammonium salt cationic collector.

[0084] S201. The intermediate is added into a solution of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysulfosuccinimide, and a MES solution is used to adjust the pH to a preset pH, then a benzyloxyamine hydrochloride is added to perform an amidation reaction, and then subjected to a desalting treatment to obtain the composite quaternary ammonium salt cationic collector.

[0085] The preset pH is 5.0-5.5.

[0086] In the embodiments, the EDC and the sulfo-NHS react with the intermediate to form a semi-stable NHS or sulfo-NHS ester, and then the MES solution is used to control the specific preset pH, so that the semi-stable NHS or sulfo-NHS ester can react with the subsequent benzyloxyamine hydrochloride to form an amide group while introducing a benzyl group, thereby obtaining the composite quaternary ammonium salt cationic collector containing quaternary ammonium groups, amide groups, linear alkyl groups and benzyl groups based on the intermediate containing quaternary ammonium groups and carboxylic acid groups.

[0087] In some optional embodiments, the structure of the composite quaternary ammonium salt cationic collector is shown in formula 1.

[0088]

[0089] Formula 1;

[0090] The R1 group includes a linear alkyl group, and X includes Cl or Br.

[0091] The carbon chain length of the linear alkyl group is 11-17.

[0092] In the embodiments, the specific structure of the composite quaternary ammonium salt cationic collector is controlled, so that the specific positions and distribution modes of the quaternary ammonium groups, the amide groups, the linear alkyl groups and the benzyl groups contained in the cation are clear, so that the collector has good water solubility, and also has the characteristics of high flotation efficiency and environmental friendliness.

[0093] At the same time, the hydrophobic benzyl group can be better matched with the introduced halide as anion, the frothing performance of the collector is improved, the foam is easy to dissipate after flotation, and the foam has good flowability.

[0094] Controlling the specific length of the linear alkyl group can make the R1 group be a long linear alkyl group, so as to improve the hydrophobicity of the collector and improve the flotation effect of the quaternary ammonium group on silicate minerals.

[0095] Based on a general inventive concept, the application provides an application of a preparation method of a composite quaternary ammonium salt cationic collector, which comprises using the composite quaternary ammonium salt cationic collector obtained by the preparation method in reverse flotation desilication of bauxite.

[0096] In the application, it is found in the application of reverse flotation desilication of bauxite that the suitable pH value for reverse flotation desilication is 5-6. The aluminum-silicon ratio of the selected bauxite is 3.55, and the grade of SiO2 is 14.29%. After flotation desilication, the aluminum-silicon ratio of the concentrate is 4.76, and the grade of SiO2 is reduced to 11.03. The grade of SiO2 in the tailings is 23.12%, and the recovery rate of SiO2 is more than 48.31%. The aluminum-silicon ratio of the selected bauxite is 5.69, and the grade of SiO2 is 10.92%. After flotation desilication, an aluminum concentrate with a yield of 77.41% is obtained, the aluminum-silicon ratio of the concentrate is 7.23, the grade of SiO2 is reduced to 8.97%, and the recovery rate of Al2O3 is 80.19%.

[0097] The application is based on the above preparation method, and the specific steps of the preparation method can refer to the above embodiments. Since the application adopts part or all of the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0098] The application will be further described below in combination with specific embodiments. It should be understood that these embodiments are only used to illustrate the application and not to limit the scope of the application. The experimental methods not specified in the following embodiments are generally determined according to national standards. If there is no corresponding national standard, the international standard, the conventional condition, or the condition suggested by the manufacturer is used.

[0099] Example 1

[0100] As shown in Figure 2 , a preparation method of a composite quaternary ammonium salt cationic collector comprises:

[0101] (1) The molar ratio of each raw material is controlled to be n (alkyl tertiary amine) : n (haloalkyl) : n (benzyloxy amine hydrochloride) = 1.2:1:1.2.

[0102] (2) The lauryl amide propyl dimethyl tertiary amine is added to the reactor, anhydrous ethanol is added and stirred for 10-20 min, then sodium chloroacetate is added dropwise, the dropwise addition is completed in 1 h, then the reaction is stirred at 40°C for 20 h, after the reaction is completed, 1 mol / L HCl is added to acidify to pH 5, vacuum condensation is performed and extraction is performed with acetone (2 x 20 mL), the organic layers are combined, washed with a brine aqueous solution (3 x 20 mL), dried with sodium sulfate and evaporated, and the residue is purified by vacuum distillation to obtain a first product.

[0103] (3) The first product is added to a solution of EDC and sulfo-NHS, MES is used as a buffer to adjust the pH value to 5.5, then a benzylamine hydrochloride solution is added dropwise, after the dropwise addition is completed, the reaction is performed at 4°C for 24 h, desalination is performed, and a cationic reverse flotation desilication collector is obtained, which is denoted as collector A.

[0104] Example 2

[0105] Example 2 and Example 1 are compared, and the difference between Example 2 and Example 1 is that:

[0106] A preparation method of a composite quaternary ammonium salt cationic collector, comprising:

[0107] (1) The molar ratio of the raw materials is controlled to be n (alkyl tertiary amine): n (haloalkyl): n (benzylamine hydrochloride) = 1:1.2:1.

[0108] (2) The lauryl amide propyl dimethyl tertiary amine is added to the reactor, anhydrous ethanol is added and stirred for 10-20 min, then sodium chloroacetate is added dropwise, the dropwise addition is completed in 1 h, then the reaction is stirred at 35°C for 19 h, after the reaction is completed, 1 mol / L HCl is added to acidify to pH 5, vacuum condensation is performed and extraction is performed with acetone (2 x 20 mL), the organic layers are combined, washed with a brine aqueous solution (3 x 20 mL), dried with sodium sulfate and evaporated, and the residue is purified by vacuum distillation to obtain a first product.

[0109] (3) The first product is added to a solution of EDC and sulfo-NHS, MES is used as a buffer to adjust the pH value to 5.5, then a benzylamine hydrochloride solution is added dropwise, after the dropwise addition is completed, the reaction is performed at 4°C for 24 h, desalination is performed, and a cationic reverse flotation desilication collector is obtained, which is denoted as collector A.

[0110] Example 3

[0111] Example 3 and Example 1 are compared, and the difference between Example 3 and Example 1 is that:

[0112] A preparation method of a composite quaternary ammonium salt cationic collector, comprising:

[0113] (1) The molar ratio of each raw material is controlled as n (alkyl tertiary amine) : n (halogenated alkyl) : n (benzyloxyamine hydrochloride) = 1.2:0.8:1.4.

[0114] (2) The lauryl amide propyl dimethyl tertiary amine is added into the reactor, anhydrous ethanol is added and stirred for 10 min to 20 min, then sodium chloroacetate is added dropwise for 1 h, and then stirred at 45°C for 19 h. After the reaction is completed, 1 mol / L HCl is added to acidify to pH 5, vacuum condensation and extraction with acetone (2 x 20 mL) is performed, the organic layer is washed with a brine solution (3 x 20 mL), dried with sodium sulfate and evaporated, and the residue is purified by vacuum distillation to obtain the first product.

[0115] (3) The first product is added into a solution of EDC and sulfo-NHS, and the pH value is adjusted to 5.5 with MES as a buffer, then a benzyloxyamine hydrochloride solution is added dropwise, and after the dropwise addition is completed, the reaction is carried out at 4°C for 25 h. After desalination, the cationic reverse flotation desilication collector is obtained, which is denoted as collector C.

[0116] Related experiments and effect data:

[0117] 1. The collectors A, B, C and conventional reverse flotation desilication collectors (such as dodecyl trimethyl ammonium chloride, lauryl amide) are used for the flotation of kaolinite pure minerals.

[0118] The flotation test is carried out on an XFG type hanging slot flotation machine, and the main shaft rotates at 1650 r / min. During the test, 3 g of minerals are placed in a 40 mL flotation tank, a certain amount (25 mL to 30 mL) of distilled water is added, and the slurry is stirred for 1 min; then the conditioning agent is added for 3 min, and then the collector is added, stirred for 3 min, and floated for 5 min. During the flotation process, the foam product is collected, and the foam product and the tank product are dried and weighed respectively to calculate the recovery rate. The test flow chart is shown in Figure 4 , and the test results are shown in Table 1.

[0119] Table 1 Comparison test results of collector flotation of kaolinite

[0120]

[0121] As can be seen from Table 1, among the prepared collectors, the collecting ability of collector A for kaolinite is the strongest, and it surpasses the existing conventional reverse flotation desilication collector.

[0122] 2. The collectors A, B, C and the existing conventional reverse flotation desilication collector are used for the flotation of illite pure minerals.

[0123] The test steps are the same as above, and the test results are shown in Table 2.

[0124] Table 2 Results of collector flotation of illite comparative test

[0125]

[0126] From Table 2, it can be seen that among the three prepared reagents, the collecting ability of collector A on illite is the strongest, and it surpasses the existing conventional reverse flotation desilication collector.

[0127] 3. Collectors A, B, C and the existing conventional reverse flotation desilication collector are used for the flotation of pure beryl minerals.

[0128] The test steps are the same as above, and the test results are shown in Table 3.

[0129] Table 3 Results of collector flotation of beryl comparative test

[0130]

[0131] From the test results of Table 3, it can be seen that the collecting ability of collector A on beryl is the strongest, and it surpasses the existing conventional reverse flotation desilication collector.

[0132] 4. Collectors A, B, C and the existing conventional reverse flotation desilication collector are used for the flotation desilication of bauxite, and the bauxite used is from Henan, and its composition analysis is shown in Table 4 and Table 5. Among them, 1227 refers to dodecyl dimethyl benzyl ammonium chloride, and 1221 refers to dodecyl trimethyl ammonium chloride.

[0133] The chemical composition analysis results of the test bauxite are shown in Table 4 and Table 5:

[0134] Table 4 Chemical composition analysis results of bauxite minerals (%)

[0135]

[0136] Table 5 Mineral phase composition analysis results of bauxite (%)

[0137]

[0138] Experimental procedure:

[0139] Step 1: Slurry preparation:

[0140] Put 250g of the mineral sample into the flotation tank of the 1.5L XFG type hanging slot type flotation machine, add tap water, and under the rotation speed of the flotation machine 2100r / min, slurry for 3min.

[0141] Step 2: Add modifier:

[0142] After the above step 1, add hydrochloric acid and depressor, adjust the pH to 5-6, and then slurry for 2min.

[0143] Step 3: adding collector:

[0144] In step 2 above, the collector is added, and flotation is carried out for 5 min, and the air valve is opened to scrape the foam.

[0145] Step 4: processing of the flotation product:

[0146] After the reverse flotation desilication process is completed, the sample mixed with the flotation foam product and middlings, i.e. the tailings and the product in the tank, i.e. the concentrate, are dried, weighed, detected and the product indexes are calculated, and the test procedure is as shown in Figure 5 , wherein the test procedure includes one roughing, one cleaning and one scavenging procedure, the mixed flotation foam and middlings are used as tailings, and the product at the tank bottom is used as concentrate, and the obtained results are as shown in Table 6.

[0147] Table 6: results of the collector flotation desilication test

[0148]

[0149] As can be seen from Table 6, among the three collectors A, B and C prepared, the collector A requires the least amount of collector, and the concentrate yield, the aluminum-silicon ratio and the aluminum recovery rate are the highest. Compared with the existing conventional collector, the collector A requires less amount, and the increase in the concentrate yield and the aluminum-silicon ratio shows that the collector A has the best desilication effect.

[0150] 5. The collector A and the existing conventional collector are used in the reverse flotation desilication of Chongqing ore.

[0151] The chemical composition analysis results of Chongqing ore are as shown in Tables 7 and 8, the test steps are the same as those of Experiment 4, and the test results are as shown in Table 9.

[0152] Table 7: chemical composition analysis results of bauxite ore (%)

[0153]

[0154] Table 8: analysis results of the phase composition of bauxite ore (%)

[0155]

[0156] Table 9: results of the reverse flotation desilication test under the optimal amount of each collector

[0157]

[0158] From Table 9, it can be seen that the optimal dosage of different collectors for reverse flotation desilication is different, the dosage of collector A is the least, and the yield of the concentrate obtained after flotation of collector A reaches 76.61%, the aluminum-silicon ratio is the highest, reaching 5.5, the aluminum recovery rate in the concentrate is higher, reaching 81.7%.

[0159] 6. An example of application of collector A in the flotation desilication open-circuit test of Shanxi bauxite.

[0160] The chemical composition analysis results of Shanxi bauxite are shown in Tables 10 and 11, the test steps are the same as those of Example 4, and the test results are shown in Table 12.

[0161] Table 10 Chemical composition analysis results of bauxite minerals (%)

[0162]

[0163] Table 11 Analysis results of bauxite mineral phase composition (%)

[0164]

[0165] The test steps are the same as those of Example 4, and the test results are shown in Table 12.

[0166] Table 12 Comparison test results of collectors for flotation of bauxite

[0167]

[0168] According to Table 12, by comprehensively comparing the concentrate yield and aluminum-silicon ratio, and the silicon recovery rate in the tailings, it can be seen that, compared with existing collectors, the collector provided in the application has better selectivity and strong collecting ability.

[0169] 7. An example of application of collector A in the flotation desilication closed-circuit test of bauxite:

[0170] The test steps are the same as those of Example 4, the test process is shown in Figure 6 , and the test results are shown in Table 13.

[0171] Table 13 Comparison test results of collectors for flotation of bauxite

[0172]

[0173] Table 13 shows that in the closed-circuit test, the collector provided in the application achieves better reverse flotation desilication effect.

[0174] The one or more technical solutions in the application embodiment have at least the following technical effects or advantages:

[0175] (1) The preparation method of the composite quaternary ammonium salt cationic collector provided in the embodiment of the application, the composite quaternary ammonium salt compound prepared by the method is more easily degraded and has more hydrophilicity due to the presence of amide groups in the molecule, and thus is more friendly to the environment and people in terminal application; and the molecule has a hydrophobic benzyl group and a quaternary ammonium group which is affinity to mineral surface groups, so that the flotation separation of oxidized ores and salt minerals can be strengthened, and the composite quaternary ammonium salt cationic collector has the characteristics of high flotation efficiency.

[0176] (2) The preparation method of the composite quaternary ammonium salt cationic collector provided in the embodiment of the application, the composite quaternary ammonium salt cationic collector prepared by the method has good water solubility and is green and safe.

[0177] (3) The application of the preparation method of the composite quaternary ammonium salt cationic collector provided in the embodiment of the application, the composite quaternary ammonium salt cationic collector obtained by the method has strong collecting ability for silicate minerals such as kaolinite and illite, is suitable for desilication by reverse flotation of bauxite, and has good selectivity and small dosage.

[0178] (4) The application of the preparation method of the composite quaternary ammonium salt cationic collector provided in the embodiment of the application, the composite quaternary ammonium salt cationic collector obtained by the method is suitable for flotation under acid pulp, is conducive to water recycling, and compared with conventional desilication collectors by reverse flotation, the composite quaternary ammonium salt cationic collector has small dosage, high concentrate aluminum-silicon ratio and high flotation efficiency.

[0179] (5) The application of the preparation method of the composite quaternary ammonium salt cationic collector provided in the embodiment of the application, the foam after flotation is easy to dissipate and has good flowability.

[0180] Various embodiments of the application can exist in the form of a range; it should be understood that the description in the form of a range is merely for the convenience and brevity, and should not be understood as a hard limitation on the scope of the application; therefore, it should be considered that the range described has specifically disclosed all possible sub-ranges and single values within the range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 5, from 3 to 5, etc., as well as single numbers within the range, such as 1, 2, 3, 4 and 5, regardless of the range. In addition, whenever a numerical range is indicated in this document, it refers to any cited number (fraction or integer) within the indicated range.

[0181] In the present application, the orientation words such as "upper" and "lower" are specifically the directions of the drawing surface in the drawings unless otherwise stated. In addition, in the description of the present application, the terms "comprise", "contain" and the like mean "comprise but not limited to". In the present text, the relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. In the present text, the "and / or" describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent: the case of A alone, the case of A and B existing at the same time, and the case of B alone. Wherein A, B can be singular or plural. In the present text, "one or more" means one or more, and "multiple" means two or more. "At least one", "at least one of the following" or the like means any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can mean a, b, c, a-b (i.e. a and b), a-c, b-c, or a-b-c, where a, b, and c can be single or multiple.

[0182] The above description is only a specific embodiment of the present application, which enables those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied herein.

Claims

1. A method for preparing a composite quaternary ammonium salt cationic collector, characterized in that, The method includes: A quaternization reaction is carried out by adding a haloalkyl group to an alkyl tertiary amine containing an amide group to obtain an intermediate; A catalyst was added to the intermediate to carry out a catalytic reaction, followed by the addition of benzyloxyamine hydrochloride to carry out an amidation reaction, and then desalting treatment was performed to obtain a composite quaternary ammonium salt cationic collector. The molar ratio of the alkyl tertiary amine, the haloalkyl group, and the benzyloxyamine hydrochloride is 1–1.4:0.8–1.2:1–1.

4. The alkyl tertiary amine is an alkyl tertiary amine with a carbon chain length of 12 to 18.

2. The preparation method according to claim 1, characterized in that, The alkyl tertiary amines include lauramide propyl dimethyl tertiary amine and / or octadecamidopropyl dimethylamine tertiary amine; and / or, The haloalkyl group includes sodium chloroacetate and / or sodium bromoacetate.

3. The preparation method according to claim 1, characterized in that, The quaternization reaction is carried out at a temperature of 30℃ to 55℃ for 18h to 24h.

4. The preparation method according to claim 1, characterized in that, The amidation reaction is carried out at a temperature of 3°C to 10°C for a duration of 22 h to 26 h.

5. The preparation method according to claim 1, characterized in that, The step of adding a haloalkyl group to an amide-containing alkyl tertiary amine to carry out a quaternization reaction to obtain an intermediate includes the following steps: A solvent was added to an alkyl tertiary amine containing an amide group and stirred for the first time. Then, a haloalkyl group was added dropwise and stirred for the second time to carry out a quaternization reaction to obtain an intermediate precursor. The pH of the intermediate precursor was adjusted, and the mixture was condensed and extracted. Then, it was evaporated and dried using a desiccant and purified by vacuum distillation to obtain an intermediate containing quaternary ammonium and carboxylic acid groups.

6. The preparation method according to claim 5, characterized in that, The first stirring time is 10 min to 20 min; and / or, The temperature of the second stirring is 35℃~45℃, and the stirring time is 19h~22h.

7. The preparation method according to claim 1, characterized in that, The process involves adding a catalyst to the intermediate for a catalytic reaction, followed by adding benzyloxyamine hydrochloride for an amidation reaction, and then performing desalting to obtain a composite quaternary ammonium salt cationic collector, comprising the following steps: The intermediate was added to a solution of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysulfosuccinimide, and the pH was adjusted to a preset level using MES solution. Then, benzyloxyamine hydrochloride was added to carry out an amidation reaction and desalting treatment to obtain a composite quaternary ammonium salt cationic collector. The preset pH is 5.0 to 5.

5.

8. The preparation method according to claim 1, characterized in that, The structural formula of the composite quaternary ammonium salt cationic collector is shown in Formula 1: Formula 1; Wherein, R1 group includes straight-chain alkane group; X includes Cl or Br; The carbon chain length of the straight-chain alkane group is 11 to 17.

9. The application of a method for preparing a composite quaternary ammonium salt cationic collector, characterized in that, The application includes using the composite quaternary ammonium salt cationic collector obtained by the preparation method according to any one of claims 1-8 in bauxite reverse flotation desilication.

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