Combined reagent for reducing foam stability of amine collector flotation lepidolite and preparation method of combined reagent

Abstract

The invention discloses a combined reagent for reducing foam stability of amine collector flotation lepidolite and a preparation method of the combined reagent, and belongs to the technical field of mineral processing. The combined reagent for reducing the flotation froth stability of the amine collector comprises the following raw materials: lauryl amine, a solubilizer and span. Compared with a conventional cationic flotation collecting agent, the combined reagent provided by the invention has the advantages that on the premise of ensuring a good flotation index of lauryl amine, the problem that lauryl amine foam is sticky can be remarkably improved, the foam stability is reduced, and the half-life period of standing defoaming of flotation foam is greatly shortened. In addition, the combined agent is stable in chemical composition and physicochemical property, high in collecting capacity, efficient and low in consumption, and has the advantages of being easy to prepare and low in price.

Description

Technical Field

[0001] The present invention relates to the technical field of mineral processing, and particularly to a combined reagent for reducing the foam stability of amine collectors in the flotation of lepidolite and a preparation method thereof. Background Art

[0002] Lithium, as a key mineral resource, plays a crucial role in the economic and social fields. In recent years, due to the rapid development of the new energy vehicle industry and the energy storage industry, the global demand for lithium resources has shown an explosive growth trend, resulting in an increasingly severe situation of supply falling short of demand in the lithium resource market. Against this background, how to efficiently and economically extract lithium elements from lithium ore resources has become a key scientific problem that urgently needs to be solved in the current resource development field.

[0003] Lepidolite, as the main target mineral for lithium extraction from lithium ore, not only contains rich lithium elements but also is associated with various rare metals, having high comprehensive utilization value. However, the composition of the original lepidolite ore is complex and diverse, and the grade of Li2O (lithium oxide) is relatively low, resulting in a dispersed occurrence state and fine dissemination size of lithium elements in the ore, which significantly increases the extraction difficulty and restricts the efficient extraction and utilization of lithium resources.

[0004] The flotation method is a commonly used method for lepidolite enrichment. In the flotation system, dodecylamine, as a typical cationic collector, has good collecting effect on lepidolite. However, dodecylamine also faces the problem of being demanding on flotation environmental conditions (such as pH value, pulp temperature, ionic strength, etc.) in the actual application process. A slight environmental fluctuation can lead to a significant decline in its collecting performance. At the same time, dodecylamine is prone to form a foam layer with a relatively high viscosity during the flotation process, which not only reduces the effective processing capacity of the flotation machine but also increases the difficulty and cost of subsequent defoaming treatment, seriously restricting the industrial application of the lepidolite flotation process and the improvement of production efficiency. Summary of the Invention

[0005] The purpose of the present invention is to provide a combined reagent for reducing the foam stability of amine collectors in the flotation of lepidolite and a preparation method thereof to solve the above problems in the background art. Compared with conventional cationic flotation collectors, the combined reagent provided by the present invention can significantly improve the problem of sticky foam of dodecylamine, reduce the foam stability, and greatly shorten the half-life of static defoaming of flotation foam on the premise of ensuring good flotation indexes of dodecylamine.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] One of the technical solutions of the present invention: provides a combined reagent for reducing the foam stability of amine collectors in flotation, including the following raw materials: dodecylamine, solubilizer, and span.

[0008] Preferably, the solubilizer is acetic acid or hydrochloric acid.

[0009] Preferably, the span is span 20, span 40, span 60 or span 80.

[0010] Preferably, the mass ratio of the dodecylamine, solubilizer and span is 1: 0.2-0.4: 0.3-3.

[0011] The second technical solution of the present invention: provides a preparation method of the above-mentioned combined agent for reducing the flotation foam stability of amine collectors, comprising the following steps:

[0012] Mix the raw materials to obtain the combined agent.

[0013] Preferably, the preparation method comprises the following steps: mix dodecylamine and a solubilizer to obtain a mixed solution; mix the mixed solution and span to obtain the combined agent.

[0014] The third technical solution of the present invention: provides an application of the above-mentioned combined agent for reducing the flotation foam stability of amine collectors in the flotation of lepidolite.

[0015] The fourth technical solution of the present invention: provides a lepidolite flotation method, using the above-mentioned combined agent for reducing the flotation foam stability of amine collectors to float minerals containing lepidolite.

[0016] Preferably, the mineral containing lepidolite is a lepidolite ore or a silicate gangue mineral of a lepidolite ore.

[0017] Preferably, the silicate gangue minerals of the lepidolite ore include muscovite, quartz or feldspar.

[0018] Preferably, the dosage ratio of the combined agent to the mineral containing lepidolite is 50-400 g / t.

[0019] Preferably, the flotation comprises the following steps:

[0020] Make the mineral containing lepidolite into pulp, then add the combined agent and carry out flotation.

[0021] Preferably, the solid content in the pulp is 5-20%.

[0022] Preferably, the mass concentration of dodecylamine in the combined agent in the pulp is 0.01-0.1%.

[0023] In the present invention, dodecylamine serves as a foaming agent and a collector, acetic acid or hydrochloric acid serves as a solubilizer, and Span serves as a foam regulator. After introducing Span into dodecylamine, the presence of Span can reduce the surface tension of dodecylamine, decrease the mutual repulsive force between the foam liquid films, enhance the movement ability of water molecules in the liquid film, accelerate the drainage rate of the liquid film, and thus reduce the foam stability of dodecylamine. In addition, after adding dodecylamine and Span simultaneously, it can also improve the hydrophobicity of mineral particles, intensify the coalescence between particles, reduce the coverage rate of particles on the foam liquid film, make the arrangement of mineral particles on the foam liquid film change from tight to loose, and accelerate the drainage of the liquid film. At the same time, since Span is a non-ionic surfactant with a charge of zero, it can neutralize the charged particles (acetate or chloride ions) in the solubilizer, inhibit the binding of the head group of dodecylamine to the charged particles, reduce the number of acetate ions or chloride ions that form a double electric layer with the gas-liquid interface, and weaken the electrostatic repulsive force between the two surfaces of the liquid film, thereby reducing the foam stability.

[0024] The beneficial technical effects of the present invention are as follows:

[0025] Compared with conventional cationic flotation collectors, the combined reagent for reducing the foam stability of amine collectors provided by the present invention can significantly improve the problem of sticky foam of dodecylamine, reduce the foam stability, and greatly shorten the half-life of static defoaming of flotation foam on the premise of ensuring good flotation indexes of dodecylamine.

[0026] In addition, the chemical composition and physical and chemical properties of the combined reagent of the present invention are stable, it has strong collecting ability, high efficiency and low consumption, and has the characteristics of simple preparation and low price.

[0027] The test results show that when flotation of lepidolite ore is carried out with the combined reagent provided by the present invention compared with only using dodecylamine collector, under the condition of comparable concentrate Li2O grade and recovery rate, the half-life of static defoaming of foam is shortened from 3200 - 3600 min to 60 - 100 min, significantly reducing the flotation foam stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 It is a schematic flow chart for flotation of minerals containing lepidolite in Application Examples 1 - 7 and Comparative Examples 1 - 3.

[0030] Figure 2It is a schematic flow chart for the flotation of minerals containing lepidolite in Application Example 8 and Comparative Example 4. Detailed implementation manners

[0031] Now, various exemplary implementation manners of the present invention will be described in detail. This detailed description should not be regarded as a limitation to the present invention, but rather as a more detailed description of certain aspects, characteristics, and implementation schemes of the present invention. It should be understood that the terms described in the present invention are only for describing specific implementation manners and are not used to limit the present invention.

[0032] In addition, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0033] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. It should be noted that the aspects not described in detail in the present invention are all conventional operating means in the art and are not the focus of the present invention.

[0034] Regarding the "comprising", "including", "having", "containing", etc. used in the present invention, they are all open-ended terms, that is, they mean including but not limited to.

[0035] The present invention provides a combined reagent for reducing the flotation foam stability of amine collectors, comprising the following raw materials: dodecylamine, solubilizer, and span.

[0036] Further, the solubilizer is acetic acid or hydrochloric acid.

[0037] Further, the span is span 20, span 40, span 60, or span 80.

[0038] Furthermore, the span is span 60 or span 80.

[0039] Further, the mass ratio of the dodecylamine, solubilizer, and span is 1:0.2 - 0.4:0.3 - 3.

[0040] The present invention also provides a preparation method of the above-mentioned combined reagent for reducing the flotation foam stability of amine collectors, comprising the following steps:

[0041] Mix the respective raw materials to obtain the combined reagent.

[0042] Further, the preparation method includes the following steps: performing a first mixing on dodecylamine and a solubilizer to obtain a mixed solution; and performing a second mixing on the mixed solution and Span to obtain the combined agent.

[0043] Furthermore, the first mixing is performed under the condition of room temperature.

[0044] Furthermore, the manner of the first mixing is stirring.

[0045] The present invention has no special limitation on the stirring rate of the first mixing, and any stirring rate well-known to those skilled in the art can be adopted; the present invention has no special limitation on the stirring time of the first mixing, and it is based on fully mixing the materials to obtain a completely mixed and homogeneous system of dodecylamine and the solubilizer.

[0046] Furthermore, the manner of the second mixing is stirring; the stirring time is 2 - 4 min, more preferably 3 - 4 min. The present invention has no special limitation on the stirring rate of the second mixing, and any stirring rate well-known to those skilled in the art can be adopted.

[0047] The present invention also provides an application of the above-mentioned combined agent for reducing the flotation foam stability of amine collectors in the flotation of lepidolite.

[0048] The present invention also provides a lepidolite flotation method, using the above-mentioned combined agent for reducing the flotation foam stability of amine collectors to float the lepidolite-containing minerals.

[0049] Further, the lepidolite-containing minerals are lepidolite ores or silicate gangue minerals of lepidolite ores.

[0050] Further, the silicate gangue minerals of lepidolite ores include muscovite, quartz or feldspar.

[0051] Further, the dosage ratio of the combined agent to the lepidolite-containing minerals is 50 - 400 g / t.

[0052] Further, the flotation includes the following steps:

[0053] Making the lepidolite-containing minerals into pulp, then adding a regulator and the combined agent, and performing flotation.

[0054] The present invention has no special limitation on the regulator, and any regulator well-known to those skilled in the art can be adopted. Specifically, for example, the regulator is hydrochloric acid or sodium hydroxide. In the present invention, the hydrochloric acid or sodium hydroxide provides the function of adjusting the pH value. The present invention has no special limitation on the dosage of the regulator, and any dosage well-known to those skilled in the art can be adopted.

[0055] Further, the particle size of the mineral particles in the pulp is 18 - 150 μm.

[0056] The present invention has no special limitation on the grading of the mineral particles in the pulp, and any grading can be adopted. Specifically, for example, the mass ratio of particles below 18 μm, particles of 18 - 38 μm, particles of 38 - 74 μm, and particles of 74 - 150 μm is 1:1:2:1.

[0057] Further, the solid content in the pulp is 5 - 20%, more preferably 5 - 15%, and further preferably 7 - 15%.

[0058] Further, the mass concentration of dodecylamine in the combined reagent in the pulp is 0.01 - 0.1%.

[0059] In the present invention, the foam half-life of the flotation foam is measured by the air flow method to characterize the stability of the flotation foam.

[0060] The specific calculation formula for the mineral recovery rate is: Mineral recovery rate = mass of the foam product / mass of the total minerals × 100%.

[0061] The floating difference is the difference in the recovery rates of different mineral components.

[0062] In the present invention, "room temperature" is calculated as 10 - 30°C unless otherwise specified.

[0063] Unless otherwise specified, the concentration of hydrochloric acid used in the following examples and comparative examples of the present invention is 36 wt%.

[0064] In the present invention, unless otherwise specified, all components used are commercially available products well-known to those skilled in the art.

[0065] Examples 1 - 4

[0066] Preparation of the combined reagent:

[0067] Prepare each raw material according to the material ratio in Table 1; mix dodecylamine and the solubilizer to obtain a mixed solution; mix the mixed solution and Span to obtain the combined reagent.

[0068] The mass fraction ratios of the raw materials in Examples 1 - 4 are shown in Table 1.

[0069] Table 1 Material ratio of Examples 1 - 4

[0070]

[0071] Application Example 1

[0072] Flotation separation of minerals:

[0073] 1) Use a jaw crusher to crush the minerals (pure mineral lepidolite, pure mineral quartz, or pure mineral albite) to a particle size of less than 1 mm, and then use a ceramic ball mill to grind the crushed minerals to obtain particles with a size of less than 18 μm, particles with a size of 18 - 38 μm, particles with a size of 38 - 74 μm, and particles with a size of 74 - 150 μm. Mix the particles with a size of less than 18 μm, particles with a size of 18 - 38 μm, particles with a size of 38 - 74 μm, and particles with a size of 74 - 150 μm according to a mass ratio of 1:1:2:1 to obtain a mixed ore.

[0074] 2) At room temperature, mix the mixed ore (pure mineral lepidolite, pure mineral quartz, or pure mineral albite) with water to prepare a 50 mL pulp with a mass percentage concentration of 10%. Then, add a HCl solution with a mass percentage concentration of 0.5% to the pulp to adjust the pH of the pulp to 2, and the pulp mixing time is 3 min. Then, add 2 mL of the combined reagent obtained in Example 1 to the pulp. After acting for 2 min, perform flotation and foam scraping for 3 min to obtain the product in the flotation cell (tailings) and the foam product (concentrate).

[0075] Test the recovery rate of the foam product obtained by flotation and the floating difference between different minerals. The test results show that the floating differences (recovery rate differences) between lepidolite (recovery rate of 97%) and quartz (recovery rate of 22%), albite (recovery rate of 10%) are 75% and 87% respectively;

[0076] Record the half-life of the static defoaming of the flotation foam. The results show that the flotation foam in this application example has good fluidity, and the half-life of the static defoaming of the flotation foam is 96 min.

[0077] Application Example 2

[0078] The difference from Application Example 1 is only that the combined reagent of Example 1 added in step 2) is replaced with an equal volume of the combined reagent of Example 2.

[0079] The test results show that the floating differences between lepidolite (recovery rate of 96%) and quartz (recovery rate of 23%), albite (recovery rate of 12%) are 73% and 84% respectively; the half-life of the static defoaming of the flotation foam is 91 min.

[0080] Application Example 3

[0081] The difference from Application Example 1 is only that the combined reagent of Example 1 added in step 2) is replaced with an equal volume of the combined reagent of Example 3.

[0082] The test results show that the floating differences between lepidolite (recovery rate of 97%) and quartz (recovery rate of 25%), albite (recovery rate of 10%) are 72% and 87% respectively; the half-life of the static defoaming of the flotation foam is 82 min.

[0083] Application Example 4

[0084] The difference from Application Example 1 is only that the combined agent of Example 1 added in step 2) is replaced with an equal volume of the combined agent of Example 4.

[0085] The test results show that the flotation differences between lepidolite (recovery rate of 98%) and quartz (recovery rate of 25%), and albite (recovery rate of 8%) are 73% and 90% respectively; the half-life of the flotation foam standing and defoaming is 79 min.

[0086] Examples 5 - 7

[0087] Preparation of the combined agent:

[0088] Prepare each raw material according to the material ratio in Table 2; mix dodecylamine and the solubilizer to obtain a mixed solution; mix the mixed solution and Span 80 to obtain the combined agent.

[0089] The mass fraction ratios of the raw materials in Examples 5 - 7 are shown in Table 2.

[0090] Table 2 Material ratio of Examples 5 - 7

[0091]

[0092] Application Example 5

[0093] The difference from Application Example 1 is only that the combined agent of Example 1 added in step 2) is replaced with an equal volume of the combined agent of Example 5.

[0094] The test results show that the flotation differences between lepidolite (recovery rate of 99%) and quartz (recovery rate of 27%), and albite (recovery rate of 15%) are 72% and 84% respectively; the half-life of the flotation foam standing and defoaming is 98 min.

[0095] Application Example 6

[0096] The difference from Application Example 1 is only that the combined agent of Example 1 added in step 2) is replaced with an equal volume of the combined agent of Example 6.

[0097] The test results show that the flotation differences between lepidolite (recovery rate of 98%) and quartz (recovery rate of 24%), and albite (recovery rate of 11%) are 74% and 87% respectively; the half-life of the flotation foam standing and defoaming is 84 min.

[0098] Application Example 7

[0099] The difference from Application Example 1 is only that the combined agent of Example 1 added in step 2) is replaced with an equal volume of the combined agent of Example 7.

[0100] The test results show that the floatation difference between lepidolite (recovery rate of 96%) and quartz (recovery rate of 20%) and albite (recovery rate of 10%) is 76% and 86% respectively; the half-life of the static defoaming of the flotation foam is 65 min.

[0101] Comparative Example 1

[0102] The difference from Application Example 1 is only that the combined reagent of Example 1 added in step 2) is replaced with an equal volume of dodecylamine.

[0103] The test results show that the floatation difference between lepidolite (recovery rate of 98%) and quartz (recovery rate of 10%) and albite (recovery rate of 7%) is 88% and 91% respectively; the half-life of the static defoaming of the flotation foam is 3400 min.

[0104] From the data comparison of the above Application Examples 1-7 and Comparative Example 1, it can be seen that when the combined reagent provided by the present invention has a comparable flotation recovery rate and mineral floatation difference to the traditional collector dodecylamine, the fluidity of the flotation foam is significantly improved, the problem of sticky flotation foam is improved, and the half-life of the static defoaming of the foam is shortened from 3400 min to 65-98 min, greatly improving the defoaming efficiency.

[0105] Comparative Example 2

[0106] The difference from Application Example 1 is only that the combined reagent of Example 1 added in step 2) is replaced with an equal volume of Sample A;

[0107] The preparation method of Sample A is as follows: prepare dodecylamine, glacial acetic acid and polydimethylsiloxane defoamer according to a mass ratio of 1:0.3:1; mix dodecylamine and glacial acetic acid to obtain a mixed solution; mix the mixed solution and the silicone defoamer to obtain Sample A.

[0108] The test results show that the floatation difference between lepidolite (recovery rate of 89%) and quartz (recovery rate of 28%) and albite (recovery rate of 15%) is 61% and 74% respectively; the half-life of the static defoaming of the flotation foam is 2880 min, and the problem of sticky dodecylamine flotation foam cannot be effectively improved.

[0109] Comparative Example 3

[0110] The difference from Application Example 1 is only that the combined reagent of Example 1 added in step 2) is replaced with an equal volume of Sample B;

[0111] The preparation method of Sample B is as follows: prepare dodecylamine, glacial acetic acid and kerosene according to a mass ratio of 1:0.3:1; mix dodecylamine and glacial acetic acid to obtain a mixed solution; mix the mixed solution and kerosene to obtain Sample B.

[0112] The test results show that the flotation differences between lepidolite (recovery rate of 94%) and quartz (recovery rate of 32%) and albite (recovery rate of 22%) are 62% and 72% respectively; the half-life of the static defoaming of the flotation foam is 1871 min, and the problem of sticky flotation foam of dodecylamine cannot be effectively improved.

[0113] Figure 1 It is a schematic flow chart for the flotation of minerals containing lepidolite in Application Examples 1-7 and Comparative Examples 1-3.

[0114] Application Example 8

[0115] Flotation object:

[0116] Low-grade lepidolite raw ore from a certain place in Fujian, the grade of lithium oxide in the raw ore is 0.372%, and the gangue minerals are mainly quartz, feldspar and muscovite.

[0117] Perform the beneficiation process as Figure 2 shown:

[0118] 1) Add 400 g of lepidolite raw ore to a ball mill for grinding to obtain lepidolite raw ore pulp; among them, the grinding concentration of grinding is 67%;

[0119] 2) Screen and deslime the lepidolite raw ore pulp obtained in step 1) to obtain flotation materials and slime; among them, the particle size of screening and desliming is 800 mesh, the screen hole size is 15 μm, and the desliming rate is 15%;

[0120] 3) Add water to adjust the flotation materials in step 2) to obtain a flotation pulp with a solid content of 20%, add it to a flotation machine for pulp adjustment for 2 min, then based on each ton of lepidolite ore (raw ore), add hydrochloric acid with a mass percentage concentration of 3% to the pulp to adjust the pulp pH = 2 and stir for 3 min, then add 200 g / t of the combined reagent obtained in Example 4 (based on lepidolite raw ore), start air flotation after stirring for 5 min, the scraping time of foam is 6 min, and lepidolite is scraped out with the foam to become flotation concentrate, and the unfloated product is flotation tailings.

[0121] It is measured that the grade of lithium oxide in the lepidolite flotation concentrate is 0.92%, and the recovery rate is 39.42%; the fluidity of the flotation foam is good, and the half-life of the static defoaming of the flotation foam is 76 min.

[0122] Comparative Example 4

[0123] The difference from Application Example 8 is only that the combined reagent of Example 4 added in step 3) is replaced by an equal mass of dodecylamine.

[0124] It is measured that the lithium oxide grade of the spodumene flotation concentrate is 0.89% and the recovery rate is 40.05%; the flotation foam is sticky, and the half-life of the static defoaming of the flotation foam is 3250 min.

[0125] Figure 2 It is a schematic flow chart of the flotation of minerals containing spodumene in Application Example 8 and Comparative Example 4.

[0126] Figure 2 It is the flotation flow chart of the spodumene raw ore, and its ore quantity is much larger than Figure 1 For the flotation scheme, if the pulp is not conditioned, it will lead to uneven dispersion of the ore particles in the pulp, making the reagent unable to fully contact the ore particles, so pulp conditioning treatment is required.

[0127] It can be seen from the comparison between Application Example 8 and Comparative Example 4 that when the combined reagent provided by the present invention has the same lithium oxide grade and recovery rate of the flotation concentrate as the traditional collector dodecylamine, the fluidity of the flotation foam is improved, the sticky situation of the flotation foam is improved, the half-life of the static defoaming of the foam is shortened from 3250 min to 76 min, the foam stability is reduced, and the defoaming efficiency is greatly improved.

[0128] The above-described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A combined reagent for reducing the flotation foam stability of amine collectors, characterized in that, It includes the following raw materials: dodecylamine, solubilizer and span.

2. The combined agent for reducing the flotation foam stability of amine collectors according to claim 1, characterized in that, The solubilizer is acetic acid or hydrochloric acid; and / or the span is span 20, span 40, span 60 or span 80.

3. The combined reagent for reducing the flotation foam stability of amine collectors according to claim 1, wherein, The mass ratio of the dodecylamine, solubilizer and span is 1:0.2 - 0.4:0.3 - 3.

4. A preparation method of a combined agent for reducing the flotation foam stability of an amine collector according to any one of claims 1-3, characterized in that, It includes the following steps: Mix the raw materials to obtain the combined reagent.

5. Application of the combined reagent for reducing the flotation foam stability of amine collector according to any one of claims 1 - 3 in the flotation of lepidolite.

6. A method for flotation of lepidolite, characterized in that, Use the combined reagent for reducing the flotation foam stability of amine collector according to any one of claims 1 - 3 to float the mineral containing lepidolite.

7. The flotation method of lepidolite according to claim 6, characterized in that The dosage ratio of the combined reagent to the mineral containing lepidolite is 50 - 400 g / t.

8. The spodumene flotation method according to claim 6, characterized in that, The flotation includes the following steps: Make the mineral containing lepidolite into pulp, then add the combined reagent for flotation.

9. The spodumene flotation method according to claim 6, wherein, The solid content in the pulp is 5 - 20%; and / or the mass concentration of dodecylamine in the combined reagent in the pulp is 0.01 - 0.1%.

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