Application of a combined collector in reverse flotation separation of lithium chlorite

Abstract

This invention discloses the application of a combined collector in reverse flotation separation of lithium chlorite, belonging to the field of mineral flotation separation technology. The combined collector comprises dodecylamine, acetic acid, and sodium oleate. The mass ratio of dodecylamine, acetic acid, and sodium oleate in the combined collector is 1:0.1-0.2:9-11. This invention uses a combined collector composed of NaOL, DDA, and acetic acid as a collector for reverse flotation separation of lithium chlorite, which can effectively separate lithium chlorite from boehmite and kaolinite in clay-type lithium ores, thereby achieving pre-enrichment of clay-type lithium ores and reducing the amount of material processed in subsequent roasting for lithium extraction. The combined collector used in this invention has advantages such as wide availability of raw materials, low cost, simple preparation, convenient use, strong collecting ability, and good foaming performance.

Description

Technical Field

[0001] This invention relates to the field of mineral flotation separation technology, and in particular to the application of a combined collector in reverse flotation separation of lithium chlorite. Background Technology

[0002] Lithium, the lightest alkali metal, possesses excellent physical and chemical properties and is widely used in numerous industries, including batteries, pharmaceuticals, ceramics, glass, and lubricants. In recent years, global demand for lithium has experienced explosive growth. Currently, the main lithium resources used industrially for producing lithium carbonate are spodumene and lithium from salt lakes. However, in recent years, large quantities of clay-type lithium deposits have been discovered, boasting advantages such as advantageous geographical locations and large reserves. Therefore, the development and utilization of clay-type lithium deposits has gradually gained attention. Currently, lithium extraction from clay-type lithium deposits is mainly achieved through direct leaching, additive roasting-water leaching, and roasting-ion exchange leaching. However, due to the low lithium grade, these methods suffer from problems such as high consumption of roasting aids or leaching reagents, severe corrosion of equipment by strong acids, and significant environmental hazards from leaching residues. Therefore, enriching clay-type lithium deposits through flotation is of great significance for the development and utilization of lithium resources.

[0003] Lithium chlorite is the main lithium-bearing mineral in clay-type lithium deposits, with its gangue minerals primarily being gibbsite and kaolinite. Therefore, the key to enriching clay-type lithium deposits lies in achieving efficient separation of lithium chlorite from gibbsite and kaolinite. However, there are currently very few reports on the flotation separation of lithium chlorite from gibbsite and kaolinite, and no corresponding highly efficient collectors exist. Therefore, developing a highly efficient flotation collector for lithium chlorite to achieve efficient separation from gibbsite and kaolinite is of great significance for the development and utilization of clay-type lithium deposits. Summary of the Invention

[0004] The purpose of this invention is to provide an application of a combined collector in reverse flotation separation of lithium chlorite, so as to solve the problems existing in the prior art.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] One of the technical solutions of the present invention is the application of a combined collector in reverse flotation separation of lithium chlorite, wherein the components of the combined collector include dodecylamine (DDA), acetic acid and sodium oleate (NaOL).

[0007] Furthermore, the mass ratio of dodecylamine, acetic acid, and sodium oleate in the combined collector is 1:0.1-0.2:9-11.

[0008] Dodecylamine and sodium oleate are used as collecting components, and acetic acid is used as a solubilizing component.

[0009] Furthermore, the reverse flotation separation of lithium chlorite specifically refers to the reverse flotation separation of lithium chlorite from clay-type lithium ore.

[0010] Furthermore, the clay-type lithium ore is a chlorite-type clay-type lithium ore.

[0011] Furthermore, the mineral composition of the clay-type lithium ore includes lithium chlorite, kaolinite, and gibbsite.

[0012] The essence of technical solution one is to provide an application of a combined collector for the flotation separation of lithium chlorite from lithium chlorite, kaolinite and boehmite.

[0013] The second technical solution of the present invention: a method for separating lithium chlorite by reverse flotation using a combination collector, comprising the following steps: mixing dodecylamine, acetic acid and sodium oleate with water to obtain a combination collector solution; crushing and ball milling the mineral and mixing it with water to obtain a slurry; adjusting the pH of the slurry to 11-12, then adding the combination collector solution, acting for 2-3 minutes, and then performing flotation and foam removal; the mass ratio of dodecylamine, acetic acid, sodium oleate and water is 1:0.1-0.2:9-11:800-1200.

[0014] Furthermore, the mineral is a clay-type lithium ore; the mineral's components include lithium chlorite, kaolinite, and gibbsite.

[0015] Further, the step of mixing dodecylamine, acetic acid, and sodium oleate with water to obtain the combined collector solution comprises: mixing 1 part by mass of dodecylamine with 0.1-0.2 parts by mass of acetic acid, adding 400-600 parts by mass of water, stirring for 5-10 minutes, then adding 9-11 parts by mass of sodium oleate and 400-600 parts by mass of water, and continuing to stir for 5-10 minutes to obtain the combined collector solution.

[0016] Furthermore, the stirring speed is 1000-1200 r / min.

[0017] Furthermore, the crushing specifically involves crushing the mineral to a particle size of less than 2 mm to obtain the crushed mineral.

[0018] Furthermore, the ball milling specifically involves ball milling the crushed minerals until the proportion of components with a particle size of less than 0.038 mm by mass is 80-90%.

[0019] Furthermore, the slurry has a mass percentage concentration of 3-20%.

[0020] Furthermore, the specific operation of adjusting the pH of the slurry to 11-12 is as follows: add a NaOH solution with a mass percentage concentration of 0.5-3% to the slurry to adjust the pH of the slurry to 11-12, and the adjustment time is 2-3 minutes.

[0021] Furthermore, the amount of the combined collector added is 3-5% of the slurry volume.

[0022] Furthermore, the flotation skimming time is 3-5 minutes.

[0023] This invention addresses the technological gap in the flotation separation of clay-type lithium ore and the flotation separation of lithium chlorite from boehmite and kaolinite. It provides a combined collector for the reverse flotation separation of lithium chlorite, consisting of collecting components sodium oleate (NaOL) and dodecylamine (DDA), and a solubilizing component acetic acid. NaOL and DDA, through hydrophobic association between hydrophobic chains and hydrogen bonding between carboxyl and amino groups, can form an associative compound with different spatial structures and physical and chemical properties than NaOL and DDA alone, under specific ratios. Different ratios of NaOL and DDA and different pH values ​​result in different spatial structures, charge characteristics, and chemical activities in the associative compound. Within a specific ratio and pH range, the associative compound can simultaneously achieve spatial structure and chemical activity matching with the surfaces of boehmite and kaolinite, forming multiple adsorption processes including physical adsorption, chemical adsorption, and hydrogen bonding, thereby achieving mineral collection. However, to ensure the selective separation of the combined collector from lithium chlorite, it is necessary to form an association with the lithium chlorite surface that exhibits steric hindrance or a significant reaction energy barrier, based on the mineral surface structure characteristics of lithium chlorite. This is primarily achieved by controlling the composition ratio and pH range of the combined collector. Acetic acid is mainly used to promote more uniform dissolution and dispersion of the agent. Therefore, the composition, ratio, and pH range of the combined collector are crucial to its collectability and selectivity.

[0024] The present invention discloses the following technical effects:

[0025] This invention uses a combined collector composed of NaOL, DDA and acetic acid as a collector for reverse flotation separation of lithium chlorite, which can effectively separate lithium chlorite from boehmite and kaolinite, thereby achieving pre-enrichment of lithium chlorite and reducing the amount of subsequent roasting for lithium extraction.

[0026] The combined collector used in this invention has the advantages of wide availability of raw materials, low cost, simple preparation, convenient use, strong collecting ability, and good foaming performance. Detailed Implementation

[0027] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0028] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0029] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0030] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0031] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0032] In the following examples and comparative examples, "room temperature" specifically refers to 20-25°C.

[0033] In the following examples and comparative examples, the mineral recovery rate = mass of foam product / mass of total minerals × 100%;

[0034] The float difference is the difference in recovery rates of different mineral components.

[0035] Example 1

[0036] (1) Preparation of combined collector solution:

[0037] At room temperature, 1 part by mass of dodecylamine and 0.1 part by mass of acetic acid were mixed, and 600 parts by mass of water were added. The mixture was stirred at 1000 r / min for 10 min. Then, 11 parts by mass of sodium oleate and 600 parts by mass of water were added, and the mixture was stirred at 1000 r / min for another 5 min to obtain a combined collector solution.

[0038] (2) Flotation separation of minerals

[0039] 1) Use a jaw crusher to crush the minerals (pure mineral lithium chlorite, pure mineral boehmite or pure mineral kaolinite) to a particle size of less than 1 mm, and then use a ceramic ball mill to ball mill the crushed minerals until the components with a particle size of less than 0.038 mm by mass account for 90%.

[0040] 2) At room temperature, the ball-milled minerals (pure lithium chlorite, pure boehmite, or pure kaolinite) are mixed with water to prepare a 60 mL slurry with a mass percentage concentration of 5%. Then, a 0.5% NaOH solution is added to adjust the pH of the slurry to 11 for 2 minutes. Next, 2.5 mL of the above-mentioned combined collector solution is added to the slurry, and after acting for 3 minutes, flotation is performed with skimming for 3 minutes to obtain the product in the flotation cell and the froth product. After drying the froth product, the recovery rates of each mineral and the flotation differences between different minerals are calculated. The flotation differences (differences in recovery rates) between lithium chlorite (recovery rate 7%) and boehmite (recovery rate 81%), and kaolinite (recovery rate 83%) are 74% and 76%, respectively. This method can achieve efficient separation of lithium chlorite from boehmite and kaolinite.

[0041] Example 2

[0042] (1) Preparation of combined collector solution:

[0043] At room temperature, 1 part by mass of dodecylamine and 0.2 parts by mass of acetic acid were mixed, 400 parts by mass of water were added, and the mixture was stirred at 1200 r / min for 10 min. Then, 9 parts by mass of sodium oleate and 600 parts by mass of water were added, and the mixture was stirred at 1200 r / min for another 10 min to obtain a combined collector solution.

[0044] (2) Flotation separation of minerals

[0045] 1) Use a jaw crusher to crush the minerals (pure mineral lithium chlorite, pure mineral boehmite or pure mineral kaolinite) to a particle size of less than 1 mm, and then use a ceramic ball mill to ball mill the crushed minerals until the components with a particle size of less than 0.038 mm by mass account for 90%.

[0046] 2) At room temperature, the ball-milled minerals (pure lithium chlorite, pure boehmite, or pure kaolinite) are mixed with water to prepare a 60 mL slurry with a mass percentage concentration of 3%. Then, a 1% NaOH solution is added to adjust the pH of the slurry to 11 for 3 minutes. Next, 2 mL of the above-mentioned combined collector solution is added to the slurry, and after acting for 3 minutes, flotation is performed with skimming for 5 minutes to obtain the product in the flotation cell and the froth product. After drying the froth product, the recovery rates of each mineral and the flotation differences between different minerals are calculated. The flotation differences between lithium chlorite (recovery rate 12%) and boehmite (recovery rate 85%), and kaolinite (recovery rate 82%) are 73% and 70%, respectively. This achieves efficient separation of lithium chlorite from boehmite and kaolinite.

[0047] Comparative Example 1

[0048] (1) Preparation of dodecylamine collector solution:

[0049] At room temperature, 1 part by mass of dodecylamine was added to 1200 parts by mass of water and stirred at 1000 r / min for 10 min to obtain a dodecylamine collector solution.

[0050] (2) Flotation separation of minerals

[0051] Same as step (2) in Example 1, except that the combined collector solution was replaced with an equal volume of the dodecylamine collector solution prepared in step (1) of this comparative example. In this comparative example, the flotation difference between lithium chlorite (recovery rate 40%) and boehmite (recovery rate 36%) and kaolinite (recovery rate 70%) decreased to 4% and 30% respectively, making separation impossible.

[0052] Comparative Example 2

[0053] (1) Preparation of sodium oleate collector solution:

[0054] At room temperature, 11 parts by weight of sodium oleate were added to 1200 parts by weight of water and stirred at 1000 r / min for 10 min to obtain a sodium oleate collector solution.

[0055] 2) Flotation separation of minerals

[0056] Same as step (2) in Example 1, except that the combined collector solution was replaced with an equal volume of the sodium oleate collector solution prepared in step (1) of this comparative example. In this comparative example, the flotation difference between lithium chlorite (recovery rate 25%) and boehmite (recovery rate 90%) and kaolinite (recovery rate 70%) decreased to 65% and 45%, respectively, which could not achieve efficient separation, and the loss rate of lithium chlorite increased by about 18%.

[0057] Comparative Example 3

[0058] (1) Preparation of combined collector solution:

[0059] At room temperature, 3 parts by mass of dodecylamine and 0.1 parts by mass of acetic acid were mixed, 600 parts by mass of water were added, and the mixture was stirred at 1000 r / min for 10 min. Then, 9 parts by mass of sodium oleate and 600 parts by mass of water were added, and the mixture was stirred at 1000 r / min for another 5 min to obtain a combined collector solution.

[0060] (2) Flotation separation of minerals

[0061] Same as step (2) in Example 1, except that the combined collector solution was replaced with an equal volume of the combined collector solution prepared in step (1) of this comparative example. In this comparative example, the floatation difference between lithium chlorite (recovery rate 79%) and boehmite (recovery rate 40%) and kaolinite (recovery rate 72%) decreased to 39% and 7%, respectively, making separation impossible.

[0062] Comparative Example 4

[0063] Similar to Example 1, the only difference is that the flotation pH in step (2) is changed to 7 (i.e., the combined collector solution is added after adjusting the pH of the pulp to 7). In this comparative example, the flotation difference between lithium chlorite (recovery rate 39%) and boehmite (recovery rate 89%) and kaolinite (recovery rate 41%) is reduced to 50% and 2%, respectively. The separation efficiency between lithium chlorite and boehmite is low, and separation from kaolinite cannot be achieved. Furthermore, the loss rate of lithium chlorite increases by more than 30%.

[0064] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for separating lithium chlorite by reverse flotation using a combination of collectors, characterized in that, The process includes the following steps: mixing 1 part by weight of dodecylamine with 0.1-0.2 parts by weight of acetic acid, adding 400-600 parts by weight of water, stirring for 5-10 minutes, then adding 9-11 parts by weight of sodium oleate and 400-600 parts by weight of water, and continuing to stir for 5-10 minutes to obtain a combined collector solution; crushing and ball milling the mineral and mixing it with water to obtain a slurry; adjusting the pH of the slurry to 11-12, then adding the combined collector solution, acting for 2-3 minutes, and then performing flotation and foam scraping. The mineral is a clay-type lithium ore; the mineral's components include lithium chlorite, kaolinite, and gibbsite.

2. The method as described in claim 1, characterized in that, The crushing process specifically involves crushing the mineral to a particle size of less than 2 mm to obtain the crushed mineral.

3. The method as described in claim 2, characterized in that, The ball milling specifically involves ball milling the crushed minerals until the proportion of components with a particle size of less than 0.038 mm by mass is 80-90%.

4. The method as described in claim 1, characterized in that, The slurry has a mass percentage concentration of 3-20%.

5. The method as described in claim 1, characterized in that, The amount of the combined collector solution added is 3-5% of the slurry volume.