Method and device for flotation of rubidium and cesium minerals from lithium slag

Abstract

The invention provides a method and device for flotation of rubidium and cesium minerals through lithium slag, and relates to the technical field of mineral processing, the method comprises the steps that the lithium slag is ground and mixed with water to prepare ore pulp, the ore pulp is placed in a flotation machine, and the mass ratio of the lithium slag to the water is 1: 3-1: 4; adding a multi-component solvent into the ore pulp to obtain an ore pulp mixed solution, stirring the ore pulp mixed solution for 5-10 minutes, and soaking the ore pulp mixed solution for 30-40 minutes after stirring so as to regulate and control the surface hydrophobicity of the rubidium-cesium minerals; stirring is conducted again, and a collecting agent and a foaming agent are sequentially added; and floating foam on the upper layer is scraped out through the scraping plate so as to recover rubidium and cesium minerals. Wherein the multi-component solvent comprises ionic liquid containing fluorine ions or sulfate ions, and the mass of the ionic liquid accounts for 5%-10% of the mass of the ore pulp; the mass of the fluorinated organic solvent is 10%-15% of the mass of the ore pulp; and the mass of the surfactant is 2-5% of the mass of the ore pulp. According to the scheme, the comprehensive utilization rate of lithium slag resources is increased, the negative influence of the flotation process on the environment is reduced, and remarkable economic benefits and social values are embodied.

Description

Technical Field

[0001] The invention relates to the technical field of mineral processing, and in particular to a method and a device for flotation of rubidium and cesium minerals using lithium slag. Background Art

[0002] With the growing global demand for new energy, the mining and utilization of lithium mineral resources has become increasingly important. As an important strategic resource, lithium is widely used in high-tech fields such as batteries, electronics, and aerospace. The mining and processing of lithium ore is not only crucial to the extraction of lithium resources, but also determines the quality and production cost of lithium products. During the mining and processing of lithium ore, a large amount of lithium slag is usually produced, and some valuable minerals such as rubidium and cesium minerals often remain in these lithium slags. Rubidium and cesium are rare metals and are widely used in electronics, communications, optoelectronics, aerospace, medicine and other fields. Especially in the manufacturing of high-end electronic products, medical imaging equipment, and nuclear technology, the demand for rubidium and cesium continues to grow. With the depletion of mineral resources and the advancement of recycling technology, the recovery of rubidium and cesium minerals in lithium slag can not only effectively utilize the remaining resources in the slag, but also reduce pollution to the environment, with significant economic and social benefits.

[0003] However, rubidium and cesium minerals in lithium slag usually exist in the form of tiny particles or composite minerals, and are often buried by other highly hydrophilic minerals. Traditional flotation solvents have limited improvement on the hydrophobicity of rubidium and cesium minerals, which can easily cause rubidium and cesium minerals to co-float with impurity minerals during the flotation process, resulting in poor separation effect. In addition, traditional solvents usually contain toxic chemical components such as chlorides and sulfides, which increases the difficulty of subsequent wastewater treatment. Summary of the invention

[0004] In order to overcome the defects of the prior art, the technical problem to be solved by the present invention is to propose a method and device for flotation of rubidium and cesium minerals from lithium slag, adopting the following technical scheme:

[0005] In one aspect, the present invention provides a method for flotation of rubidium and cesium minerals from lithium slag, comprising the following steps:

[0006] S10: grinding the lithium slag and mixing it with water to prepare a slurry, which is placed in a flotation machine, wherein the mass ratio of the lithium slag to water is 1:3 to 1:4;

[0007] S20: adding a multi-component solvent to the slurry to obtain a slurry mixture, stirring the slurry mixture for 5 to 10 minutes, and soaking the mixture for 30 to 40 minutes after stirring to adjust the surface hydrophobicity of the rubidium-cesium mineral;

[0008] S30: stirring again, and adding a collector and a frother in sequence;

[0009] S40: scraping off the upper foam by a scraper to recover the rubidium-cesium minerals;

[0010] The above-mentioned multi-component solvent includes:

[0011] An ionic liquid containing fluoride ions or sulfate ions, the mass of which is 5% to 10% of the mass of the slurry;

[0012] Fluorinated organic solvent, the mass of which is 10% to 15% of the mass of the slurry;

[0013] The surfactant is 2% to 5% of the mass of the slurry.

[0014] As a further improvement, in step S20, the temperature of the slurry mixture is controlled at 25°C to 30°C.

[0015] As a further improvement, in step S30, a pH regulator is added to adjust the pH value of the slurry mixture to 6-7.

[0016] As a further improvement, the above ionic liquid is 1-butyl-3-methylimidazolium hexafluorophosphate.

[0017] As a further improvement, the above-mentioned fluorinated organic solvent is fluorochloroolefin or tetrafluoroethylene.

[0018] As a further improvement, the above surfactant is aminomethyltrimethylsilane.

[0019] As a further improvement, the collector comprises 3 parts of olefin polymer and 1 part of fatty acid salt, and the added amount is 10-15 g / t; the foaming agent comprises a polyvinyl alcohol derivative, and the added amount is 10-20 g / t.

[0020] The present invention further provides a device for flotation of rubidium and cesium minerals from lithium slag, comprising:

[0021] An inner tank body, used for containing the above-mentioned ore pulp or ore pulp mixture;

[0022] The outer tank body is arranged outside the inner tank body and is used to contain the scraped rubidium-cesium minerals;

[0023] A feeding pipe, the feeding pipe is fixedly arranged in the middle of the inner tank body, the upper end of the feeding pipe is provided with a feeding port, and the lower end of the feeding pipe is provided with a discharge port;

[0024] The stirring assembly includes a motor and a rotating shaft. The rotating shaft is sleeved on the feeding pipe. The motor is connected to the rotating shaft through a transmission belt. The lower end of the rotating shaft is provided with an agitator for stirring the slurry. The middle part is provided with a plurality of scrapers for scraping the foam on the upper surface of the slurry mixture and making it fall into the outer tank.

[0025] As a further improvement, the bottom of the inner tank body is provided with a first drain outlet extending to the outside of the outer tank body; and the bottom of the outer tank body is provided with a second drain outlet.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] First, the present invention significantly improves the surface hydrophobicity of rubidium-cesium minerals in lithium slag by adding a multi-component solvent, including an ionic liquid containing fluoride ions or sulfate ions, a fluorinated organic solvent, and a surfactant, to the ore pulp, effectively solves the problem of co-floating rubidium-cesium minerals with hydrophilic impurity minerals, reduces the difficulty of mineral separation, and improves flotation efficiency and separation purity. At the same time, the ionic liquid and the fluorinated organic solvent in the multi-component solvent have high chemical stability, reduce the cost of wastewater treatment, and have the characteristics of green environmental protection.

[0028] Secondly, the present invention provides a better penetration environment for the multi-component solvent by controlling the temperature at 25°C to 30°C during the soaking stage, making it easier for fluoride ions, sulfate ions or fluorinated organic molecules to form a hydrophobic modified layer, avoiding volatilization due to high temperature or insufficient penetration due to low temperature. On the other hand, the pH value is controlled at 6 to 7 during the flotation stage, so that impurity minerals such as silicates and oxide minerals maintain strong hydrophilicity, thereby reducing co-floatation and improving the separation purity of rubidium and cesium minerals.

[0029] Thirdly, the flotation machine used in the present invention comprises an outer tank body, an inner tank body, a feed pipe and a stirring assembly. The inner tank body holds the ore pulp, and a multi-component solvent, a collector and a frother are sequentially injected through the feed pipe. The stirrer below the stirring assembly performs sufficient stirring. At the same time, the scraper on the stirring assembly can also scrape the foam above the ore pulp mixture to the outer tank body. The inner tank body and the outer tank body are respectively provided with a first drain port and a second drain port for collecting rubidium-cesium minerals and discharging waste liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 The present invention is a flow chart of the method for flotation of rubidium and cesium minerals from lithium slag;

[0032] Figure 2 This is a schematic diagram of the overall structure of the device for flotation of rubidium and cesium minerals from lithium slag according to the present invention;

[0033] Figure 3 It is a side cross-sectional view of the device for flotation of rubidium and cesium minerals from lithium slag according to the present invention;

[0034] Figure 4 It is a schematic diagram of the local structure of the bottom of the stirring component of the present invention.

[0035] Reference numerals:

[0036] 1-inner tank body; 2-outer tank body; 3-feeding pipe; 4-motor; 5-rotating shaft; 6-bracket;

[0037] 11-first drain outlet; 21-second drain outlet; 22-through hole; 31-feeding port; 32-discharging port; 33-flow guide port; 41-transmission belt; 51-agitator; 52-sleeve;

[0038] 331-feeding channel; 511-blade; 512-allowance hole; 521-scraper; DETAILED DESCRIPTION

[0039] In order to facilitate understanding by those skilled in the art, the structure of the present invention is further described in detail with reference to the embodiments in conjunction with the accompanying drawings:

[0040] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. The orientation or positional relationship indicated by the terms "portion", "side", "end", etc. is based on the orientation or positional relationship shown in the drawings and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

[0041] like Figure 2-Figure 4 The device for flotation of rubidium and cesium minerals from lithium slag shown in the figure comprises an inner tank body 1, an outer tank body 2, a feed pipe 3 and a stirring assembly. The inner tank body 1 is used to contain the above-mentioned ore pulp or ore pulp mixture, and is arranged inside the outer tank body 2. The feed pipe 3 is fixed inside the inner tank body 1, and a feed port 31 is arranged at the upper end thereof, and a discharge port 32 is arranged at the lower end thereof. The stirring assembly comprises a motor 4 and a rotating shaft 5. The rotating shaft 5 is sleeved on the above-mentioned feed pipe 3. The motor 4 is rotatably connected to the rotating shaft 5 through a transmission belt 41. The motor 4 is a rotary motor 4. When started, the rotating shaft 5 is rotated around the feed pipe 3. An agitator 51 is arranged at the lower end of the rotating shaft 5, and a plurality of scrapers 521 are arranged in the middle. The lower edge of the scraper 521 abuts against the upper edge of the inner tank body 1, and the purpose is to scrape the floating foam on the upper surface of the inner tank body 1, and the suspended floating foam is transferred into the outer tank body 2 by gravity.

[0042] In a specific embodiment, the inner tank body 1 and the outer tank body 2 are both circular tank bodies, the outer diameter of the inner tank body 1 is smaller than the outer diameter of the outer tank body 2, and after the inner tank body 1 is placed in the outer tank body 2, a receiving cavity is formed between the outer wall of the inner tank body 1 and the inner wall of the outer tank body 2, and the floating foam scraped off by the scraper 521 falls into the receiving cavity for separation and collection. The outer tank body 2 is provided with an upper cover, and the upper cover is provided with a through hole 22, and the rotating shaft is passed through the through hole 22.

[0043] Furthermore, as a preference, a bracket 6 is provided at the bottom of the inner tank body 1 , and the bracket 6 is provided with a plurality of suspended supporting feet, allowing the floating foam to flow from the bottom surface of the inner tank body 1 , so as to facilitate the subsequent collection of the floating foam.

[0044] In one embodiment, the feed pipe 3 and the rotating shaft 5 are both hollow cylindrical structures. The rotating shaft 5 is sleeved on the outside of the feed pipe 3. The lower end of the rotating shaft 5 is connected to the stirrer 51 by bolts. The stirrer 51 has multiple blades 511. When the motor 4 drives the rotating shaft 5 to rotate, the stirrer 51 is driven to rotate, and stirring is performed from the bottom of the inner tank body 1. It should be emphasized that an opening is provided in the middle of the stirrer 51, which serves as a clearance hole 512 for the feed pipe 3. The feed port 31 of the feed pipe 3 is located below the horizontal position of the clearance hole 512. When feeding, the solvent flows out from the inside of the stirrer 51 through the feed pipe 3, and is evenly dispersed into the ore slurry through the multiple blades 511 of the stirrer 51 to form an ore slurry mixture.

[0045] As a preference, Figure 3-Figure 4 As shown, a trumpet-shaped guide port 33 is provided at the upper end of the discharge port 31, and a partition is provided at the guide port 33 to form three discharge channels 331. In this embodiment, an injection device (not shown in the figure) is provided at the upper end of the guide port 33, and lithium slag, water and other materials or solvents are injected into the three discharge channels 331 respectively, so as to facilitate real-time adjustment of the ratio.

[0046] It should be pointed out that if Figure 4 As shown, this view is intended to show the position of the discharge port 31 and does not indicate the assembly relationship. In a specific embodiment, the trumpet-shaped guide port 33 at the upper end of the discharge port 31 is detachable, and the discharge pipe 3 is first fixed to the bottom of the inner tank body 1 by fasteners, or welded to the bottom of the inner tank body 1, and then the agitator 51 and the rotating shaft are sleeved on the outside of the discharge pipe 3 from the upper end of the discharge pipe 3.

[0047] like Figure 2-Figure 3 As shown, a sleeve 52 is provided on the rotating shaft in a height-adjustable manner, and four scrapers 521 are provided on the sleeve 52. The sleeve 52 and the hanging plate are fixed to the rotating shaft at a suitable height by a clamp or other fixed connection method. When the rotating shaft rotates, the scrapers 521 rotate with it. Preferably, the feed pipe 3 is provided at the center of the cylindrical inner tank body 1, and the length of the scrapers 521 matches the inner diameter of the inner tank body 1. When flotation is performed, the liquid level in the inner tank body 1 is close to the upper edge of the inner tank body 1. When the scrapers 521 rotate with the rotating shaft 5, the floating foam is scraped away from the rotating shaft 5 and falls into the outer tank body 2.

[0048] Further, such as Figure 3As shown, the bottom of the inner tank body 1 is provided with a first drain port 11 extending to the outside of the outer tank body 2; the bottom of the outer tank body 2 is provided with a second drain port 21. The first drain port 11 is used to discharge and recover the slurry mixture, and the second drain port 21 is used to collect froth, that is, to collect the floated rubidium-cesium minerals.

[0049] like Figure 1 As shown, the present application provides a method for flotation of rubidium and cesium minerals from lithium slag, comprising the following steps:

[0050] S10: Grinding the lithium slag and mixing it with water to prepare a slurry, which is placed in the inner tank 1, wherein the mass ratio of the lithium slag to water is 1:3 to 1:4;

[0051] S20: adding a multi-component solvent to the slurry to obtain a slurry mixture, stirring the slurry mixture for 5 to 10 minutes, and soaking the mixture for 30 to 40 minutes after stirring to adjust the surface hydrophobicity of the rubidium-cesium mineral;

[0052] S30: stirring again, and adding a collector and a frother in sequence;

[0053] S40: scraping off the upper froth through the scraper 521 to recover the rubidium-cesium minerals.

[0054] Wherein, the above-mentioned multi-component solvent comprises:

[0055] An ionic liquid containing fluoride ions or sulfate ions, the mass of which is 5% to 10% of the mass of the slurry;

[0056] Fluorinated organic solvent, the mass of which is 10% to 15% of the mass of the slurry;

[0057] The surfactant is 2% to 5% of the mass of the slurry.

[0058] As an industrial byproduct, lithium slag is usually in the form of blocks or coarse particles, and it is difficult to fully separate the minerals by direct flotation. In step S10, the lithium slag is first ground, usually by a ball mill, a rod mill or other types of grinding equipment. The main purpose of grinding is to refine the lithium slag particles to a particle size range suitable for flotation, increase the specific surface area of ​​the mineral particles, and increase the contact area with the flotation reagent. At the same time, the refined particles can be more easily mixed with water to form a stable slurry. The lithium slag and water are mixed in a mass ratio of 1:3 to 1:4 to ensure that the slurry has suitable fluidity, which is convenient for the uniform distribution of reagents and subsequent operations.

[0059] In step S20, the ionic liquid containing fluoride ions or sulfate ions has excellent interfacial activity and solubility. The fluoride ions or sulfate ions can interact with the surface of the rubidium-cesium mineral to form a thin film on the surface of the rubidium-cesium mineral, thereby enhancing the hydrophobicity of the rubidium-cesium mineral and improving its adhesion during the flotation process to avoid co-floating with impurity minerals with strong hydrophilicity.

[0060] Furthermore, the concentration of the ionic liquid is set at 5% to 10% of the mass of the ore pulp. This ratio can significantly improve the flotation performance of the rubidium-cesium mineral, and has high chemical stability, which can effectively inhibit the decomposition of the solvent and the problem of uneven solubility.

[0061] In step S20, the fluorinated organic solvent has strong hydrophobicity and chemical stability. The fluorinated solvent molecules are rich in fluorine atoms, which further enhances the surface hydrophobicity of the rubidium-cesium mineral and improves the binding ability of the rubidium-cesium mineral with bubbles, thereby improving the flotation efficiency.

[0062] Furthermore, the addition amount of the fluorinated organic solvent is set at 10% to 15% of the slurry mass. This concentration can effectively improve the hydrophobicity of the mineral surface while avoiding excessive use of fluorinated solvents and preventing excessive hydrophobicity of the flotation environment, resulting in insufficient mineral separation or excessive consumption of solvents.

[0063] In step S20, the role of the surfactant in the flotation process is to provide super-hydrophobic surface treatment for the rubidium-cesium mineral. Its molecular structure contains hydrophilic and hydrophobic groups, which can form a uniform super-hydrophobic film on the surface of the mineral to increase the flotation of the mineral.

[0064] Furthermore, the mass of the surfactant is set to 2% to 5% of the mass of the slurry, and this concentration can form a stable super-hydrophobic film on the surface of the rubidium-cesium mineral.

[0065] The above ratio achieves separation by enhancing the hydrophobicity of rubidium-cesium minerals. Other impurity minerals in lithium slag (such as quartz, feldspar, mica, etc.) usually have strong hydrophilicity and are not easily changed by multi-component solvents. Therefore, they will not be activated by the solvent system together with rubidium-cesium minerals or cause co-floating phenomenon.

[0066] In a specific embodiment, the ionic liquid is 1-butyl-3-methylimidazolium hexafluorophosphate; the fluorinated organic solvent is fluorochloroolefin or tetrafluoroethylene; and the surfactant is aminomethyltrimethylsilane.

[0067] In step S20, the slurry temperature is controlled between 25°C and 30°C. The appropriate temperature helps to improve the solubility of the solvent, promote the reaction between the solvent and the mineral, and ensure the adhesion between the mineral particles and the bubbles. Too low a temperature will affect the permeability of the solvent, and too high a temperature may cause excessive volatilization of the solvent or damage to the surface structure of the mineral.

[0068] In step S30, the collector includes 3 parts of olefin polymer and 1 part of fatty acid salt, and the addition amount is 10-15 g / t; the above-mentioned foaming agent includes polyvinyl alcohol derivative, and the addition amount is 10-20 g / t.

[0069] Specifically, olefin polymers are collectors commonly used in mineral flotation. Olefin polymers have strong molecular lipophilicity and can form a hydrophobic layer on the surface of the mineral, effectively increasing the hydrophobicity of the rubidium-cesium mineral, enabling it to effectively attach to bubbles and improve the flotation effect. The role of fatty acid salts is mainly to change the hydrophilicity of the mineral surface by interacting with metal ions or organic matter on the surface of the mineral, making it more hydrophobic and further promoting the flotation of the mineral. In the flotation of rubidium-cesium minerals, the addition of fatty acid salts can enhance the affinity between the mineral and the collector, thereby improving the flotation performance of the rubidium-cesium mineral.

[0070] On the other hand, polyvinyl alcohol derivatives can form stable foam during the flotation process, making the flotation foam less likely to break, ensuring that the mineral particles can adhere to the bubble surface for a long time, effectively improving the flotation efficiency of rubidium and cesium minerals. At the same time, it not only has good foaming performance, but is also environmentally friendly and non-toxic, meeting the requirements of green flotation technology and reducing negative impacts on the environment.

[0071] In step S30, a pH regulator is added to adjust the pH value of the slurry mixture to 6-7. In a specific embodiment, the pH regulator is sodium citrate. Under a pH value of 6-7, the activity of the collector and the frother is fully exerted, and the collector and the frother can be more effectively combined with the rubidium-cesium mineral, promote the flotation of the rubidium-cesium mineral, and improve the controllability and stability of the flotation process.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for flotation of rubidium and cesium minerals from lithium slag, characterized in that: The following steps are involved: S10: grinding the lithium slag and mixing it with water to prepare a slurry, wherein the mass ratio of the lithium slag to the water is 1:3 to 1:4; S20: adding a multi-component solvent to the slurry to obtain a slurry mixture, stirring the slurry mixture for 5 to 10 minutes, and soaking the mixture for 30 to 40 minutes after stirring to adjust the surface hydrophobicity of the rubidium-cesium mineral; S30: stirring again, and adding a collector and a frother in sequence; S40: scraping off the upper foam through a scraper and collecting it to recover rubidium and cesium minerals; The multi-component solvent comprises: An ionic liquid containing fluoride ions or sulfate ions, the mass of which is 5% to 10% of the mass of the slurry; Fluorinated organic solvent, the mass of which is 10% to 15% of the mass of the slurry; The surfactant accounts for 2% to 5% of the mass of the slurry.

2. The method for flotation of rubidium and cesium minerals from lithium slag as claimed in claim 1, characterized in that: In step S20, the temperature of the slurry mixture is controlled at 25°C to 30°C.

3. The method for flotation of rubidium and cesium minerals from lithium slag as claimed in claim 1, characterized in that: In step S30, a pH adjuster is added to adjust the pH value of the slurry mixture to 6-7.

4. The method for flotation of rubidium and cesium minerals from lithium slag as claimed in claim 1, characterized in that: The ionic liquid is 1-butyl-3-methylimidazolium hexafluorophosphate.

5. The method for flotation of rubidium and cesium minerals from lithium slag as claimed in claim 1, characterized in that: The fluorinated organic solvent is fluorochloroolefin or tetrafluoroethylene.

6. The method for flotation of rubidium and cesium minerals from lithium slag according to claim 1, characterized in that: The surfactant is aminomethyltrimethylsilane.

7. The method for flotation of rubidium and cesium minerals from lithium slag according to claim 1, characterized in that: The collector comprises 3 parts of olefin polymer and 1 part of fatty acid salt, and the addition amount is 10-15 g / t; the foaming agent comprises polyvinyl alcohol derivative, and the addition amount is 10-20 g / t.

8. A device for flotation of rubidium and cesium minerals from lithium slag, characterized in that: The method for flotation of rubidium and cesium minerals using lithium slag as described in any one of the above items comprises: An inner tank body (1) is used to contain the ore pulp or ore pulp mixture; An outer tank body (2) is arranged outside the inner tank body (1) and is used to contain the scraped rubidium-cesium minerals; A feeding pipe (3), the feeding pipe (3) is fixedly arranged in the middle of the inner tank body (1), the upper end of the feeding pipe (3) is provided with a feeding port (31), and the lower end of the feeding pipe (3) is provided with a discharging port (32); The stirring assembly comprises a motor (4) and a rotating shaft (5), wherein the rotating shaft (5) is sleeved on the feeding pipe (3), the motor (4) is connected to the rotating shaft (5) via a transmission belt (41), a stirrer (51) for stirring the slurry is arranged at the lower end of the rotating shaft (5), and a plurality of scrapers (521) are arranged in the middle part for scraping the foam on the upper surface of the slurry mixture and causing it to fall into the outer tank body (2).

9. The device for flotation of rubidium and cesium minerals from lithium slag as claimed in claim 8, characterized in that: The bottom of the inner tank body (1) is provided with a first drain port (11) extending to the outside of the outer tank body (2); the bottom of the outer tank body (2) is provided with a second drain port (21).

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