Method for obtaining ceramic-grade lithium concentrate from lithium-beryllium composite ore through gravity-magnetic combined separation

Abstract

The invention relates to the technical field of ore lithium extraction, in particular to a method for obtaining ceramic-grade lithium concentrate through gravity-magnetic combined separation of lithium-beryllium composite ore. The method has the beneficial effects that error cognition of technicians in the field is broken through, and low-density dense media are used for separation; lithium concentrate is directly obtained in a dense medium mineral separation mode; lithium-beryllium separation is realized; the flotation amount is reduced, and the cost is low.

Description

Technical Field

[0001] This invention relates to the field of lithium extraction technology from ores, specifically a method for obtaining ceramic-grade lithium concentrate from lithium-beryllium composite ores through gravity and magnetic separation. Background Technology

[0002] Lithium, as a crucial rare element for promoting modernization and the development of related industries such as science and technology, is one of the most promising new energy sources. It is widely used in high-energy lithium batteries, the rubber industry, aerospace, ceramics, lasers, medicine, welding, explosives, cement, metallurgy, and new energy, earning it the title of "the energy metal of the 21st century." Many countries, considering both economic development needs and national security, have designated lithium and its high-purity lithium salts as reserve materials and are conducting extensive research on their application technologies.

[0003] Existing lithium extraction methods mainly include lithium extraction from lithium ore and lithium extraction from lithium-containing salt lakes.

[0004] Lithium extraction from ore is currently the primary method. The mined ore needs to be processed into high-grade concentrate before it can enter the smelting process.

[0005] The beneficiation process for lithium ore is divided into heavy media separation and flotation. Heavy media separation utilizes the density differences of different components in the ore to separate them. Its advantages include low beneficiation cost and no pollution.

[0006] The principle of heavy media mineral processing lies in the physical separation of components based on density differences. The density of the heavy media needs to be between that of the heavy and light components. For components with similar densities, heavy media mineral processing typically cannot directly yield a concentrate.

[0007] Traditional view holds that the density of lithium-beryllium composite ore is typically 2.7 g / cm³. 3 The density of lithium concentrate is approximately 3.0–3.2 g / cm³. 3 The density of beryllium concentrate is 2.8–3.0 g / cm³. 3 Impurities such as feldspar and quartz have a density of 2.6–2.8 g / cm³. 3 Because the three components that need to be separated have similar densities and overlap, it is impossible to directly separate them using heavy media methods to obtain a concentrate.

[0008] In existing technologies, a density of 2.5–3.2 g / cm³ is typically used. 3 Pre-separation of the raw ore using heavy media can only pre-enrich the lithium ore to a grade of less than 4.8% (m / m% as Li2O). Subsequent flotation and other operations are required to obtain qualified lithium concentrate.

[0009] Compared to flotation, heavy media separation offers advantages such as lower cost and no pollution. Therefore, how to utilize heavy media separation to separate lithium-beryllium composite ores and directly obtain lithium concentrate (grade above 6%, calculated as Li2O, m / m%) while reducing flotation volume is a problem urgently needing to be solved by those skilled in the art. Summary of the Invention

[0010] The technical problem to be solved by the present invention is to provide a method for obtaining ceramic-grade lithium concentrate by gravity and magnetic separation of lithium-beryllium composite ore, which solves the problems existing in the prior art.

[0011] One of the objectives of this invention is to achieve the acquisition of lithium concentrate using a heavy media method;

[0012] The second objective of this invention is to solve the problem of low recovery rate of lithium concentrate obtained using a simple heavy medium method.

[0013] This invention discloses a method for obtaining ceramic-grade lithium concentrate from lithium-beryllium composite ores through gravity and magnetic separation, comprising the following steps:

[0014] S1, Broken;

[0015] S2. Screening; The lithium ore obtained by screening has a particle size of -6.0mm to +0.5mm;

[0016] S3, mineral processing;

[0017] Step S3 employs a heavy media beneficiation process, using a pressureless heavy media hydrocyclone with a heavy media density of 2.33–2.46 g / cm³. 3 The specific steps are as follows:

[0018] S31. The product of step S2 is introduced into the first heavy medium hydrocyclone to obtain heavy medium lithium tailings and first heavy medium lithium middlings.

[0019] S32. The first heavy medium lithium ore obtained in step S31 is introduced into the second heavy medium hydrocyclone to obtain heavy medium lithium ore and heavy medium crude lithium concentrate.

[0020] S33. The magnetic field strength obtained in step S32 is introduced into a dry magnetic separator with a magnetic field strength of 8000-12000 Gs.

[0021] Magnetic separation concentrate can be processed through a roughing-refining-refining-refining process to obtain spodumene concentrate with a grade of over 6% and an Fe2O3 content of 0.3-0.6%.

[0022] The spodumene concentrate is used directly for smelting; the heavy medium lithium middlings enters the subsequent flotation step for further purification and separation of lithium and beryllium.

[0023] Furthermore, the frequency of the heavy medium cyclone in step S3 is 22–40 Hz.

[0024] Furthermore, in step S3, the diameter of the heavy medium cyclone separator's sand discharge nozzle is 50–65 mm.

[0025] The beneficial effects of this invention are as follows:

[0026] 1. Overcoming the misconceptions held by those skilled in the art, separation is achieved using low-density heavy media;

[0027] 2. Lithium concentrate can be obtained directly through heavy media separation.

[0028] 3. Lithium-beryllium separation was achieved;

[0029] 4. Reduced flotation volume, resulting in lower costs. Attached Figure Description

[0030] Figure 1 Flowchart. Detailed Implementation

[0031] The specific embodiments of the present invention will be further described below with reference to the examples. The following examples are only used to illustrate the technical embodiments of the present invention more clearly, and should not be used to limit the scope of protection of the present invention.

[0032] Sources of lithium-beryllium composite ore raw materials:

[0033] The lithium ore was selected from the Dahongliutan lithium-beryllium polymetallic mine in Hotan County, Xinjiang Uygur Autonomous Region. Its composition is as follows:

[0034] Table 1. Composition of Ore Raw Materials

[0035] Components (based on metal oxides) Content (m / m%) <![CDATA[Li2O]]> 1.39 BeO 0.040 <![CDATA[Ta2O5]]> 0.0031 <![CDATA[Nb2O5]]> 0.0062

[0036] Example 1

[0037] A method for obtaining ceramic-grade lithium concentrate from lithium-beryllium composite ore by gravity and magnetic separation includes the following steps:

[0038] S1, Broken;

[0039] S2, screening;

[0040] The lithium ore obtained by screening has a particle size of -6.0 mm to +0.5 mm;

[0041] S3, mineral processing;

[0042] The S3 step adopts a heavy medium beneficiation process, using a pressureless heavy medium hydrocyclone for beneficiation. The frequency of the heavy medium hydrocyclone is 40Hz, and the diameter of the sand discharge nozzle of the heavy medium hydrocyclone is 55mm.

[0043] The density of the heavy medium used is 2.46 g / cm³. 3 ;

[0044] The specific steps are as follows:

[0045] S31. The product of step S2 is introduced into the first heavy medium hydrocyclone to obtain heavy medium lithium tailings and first heavy medium lithium middlings.

[0046] S32. The first heavy medium lithium ore obtained in step S32 is introduced into the second heavy medium hydrocyclone to obtain heavy medium lithium ore and heavy medium lithium concentrate.

[0047] S33. Introduce the heavy medium lithium rough concentrate obtained in step S32 into a dry magnetic separator with a magnetic field strength of 8000-12000 Gs.

[0048] Magnetic separation concentrate can be processed through a roughing-refining-refining-refining process to obtain spodumene concentrate with a grade of over 6% and an Fe2O3 content of 0.3-0.6%.

[0049] The spodumene concentrate is used directly for smelting; the heavy medium lithium middlings enters the subsequent flotation step for further purification and separation of lithium and beryllium.

[0050] See attached flowchart Figure 1

[0051] Examples 2-9

[0052] The only difference between Examples 2-9 and Example 1 is the operating parameters. Specific parameters for each example are shown in Table 2 below:

[0053] Table 2. Operating Parameters for Examples

[0054]

[0055] The products after mineral processing in the above embodiments were analyzed, and the results are shown in Tables 3 and 4 below:

[0056] Table 3 Experimental Results of Examples - 1

[0057]

[0058] Table 4 Experimental Results of Examples - Table 2

[0059]

[0060]

[0061] The above test data shows that:

[0062] 1. The method described in this invention achieves the use of low density (density of 2.33–2.46 g / cm³). 3 The purpose is to obtain lithium concentrate by direct beneficiation of heavy media.

[0063] 2. The obtained lithium concentrate has a high recovery rate (41.2-72.0%).

[0064] 3. Lithium-beryllium separation has been achieved (most of the beryllium is found in heavy medium lithium tailings and heavy medium lithium middlings, while heavy medium lithium concentrate contains very little beryllium).

[0065] To further illustrate the beneficial effects of the present invention, the following comparative examples are provided:

[0066] Comparative Examples 1-7

[0067] Compared with the examples, Comparative Examples 1-7 mainly differ in that the hydrocyclone without pressure medium is replaced with a hydrocyclone with pressure medium. The specific operation is as follows:

[0068] S1, Broken;

[0069] S2, screening;

[0070] S3, mineral processing;

[0071] Step S3 employs a heavy media mineral processing technology, using a pressurized heavy media hydrocyclone for mineral processing. The specific steps are as follows:

[0072] The product of step S2 is introduced into a heavy medium cyclone separator to directly obtain lithium middlings and lithium tailings in the first heavy medium in one step.

[0073] The parameters for specific implementation embodiments are shown in Table 5 below:

[0074] Table 5 Comparative Operation Parameters Table

[0075]

[0076] The results of the analysis of products from ratios 6 and 7 are shown in the table below:

[0077] Table 6 Comparative Experiment Results Table-1

[0078]

[0079]

[0080] Table 7 Comparative Experiment Results - 2

[0081]

[0082] The test results of Comparative Examples 1 to 7 show that the pressurized heavy medium hydrocyclone cannot select qualified lithium concentrate by first discarding the tailings (the highest grade selected is 3.7%, which cannot meet the requirement of 6%).

[0083] Therefore, it can be seen that the beneficial effects of this invention can only be achieved by using a pressureless heavy medium cyclone separator in combination with a low-density heavy medium within a specific numerical range, employing a tail-throwing method. The synergistic effect of all three is indispensable.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for obtaining ceramic-grade lithium concentrate from lithium-beryllium composite ore through gravity and magnetic separation, characterized in that, Includes the following steps: S1, Broken; S2. Screening; The lithium ore obtained by screening has a particle size of -6.0mm to +0.5mm; S3, mineral processing; Step S3 employs a heavy media beneficiation process, using a pressureless heavy media hydrocyclone with a heavy media density of 2.33–2.46 g / cm³. 3 The specific steps are as follows: S31. The product of step S2 is introduced into the first heavy medium hydrocyclone to obtain heavy medium lithium tailings and first heavy medium lithium middlings. S32. The first heavy medium lithium ore obtained in step S31 is introduced into the second heavy medium hydrocyclone to obtain heavy medium lithium ore and heavy medium crude lithium concentrate. S33. The magnetic field strength obtained in step S32 is introduced into a dry magnetic separator with a magnetic field strength of 8000-12000 Gs. Magnetic separation concentrate can be processed through a roughing-refining-refining-refining process to obtain spodumene concentrate with a grade of over 6% and an Fe2O3 content of 0.3-0.6%. The spodumene concentrate is used directly for smelting; the heavy medium lithium middlings enters the subsequent flotation step for further purification and separation of lithium and beryllium.

2. The method for obtaining ceramic-grade lithium concentrate from lithium-beryllium composite ore by gravity and magnetic separation according to claim 1, characterized in that, The frequency of the heavy medium cyclone in step S3 is 22-40 Hz.

3. The method for obtaining ceramic-grade lithium concentrate by gravity and magnetic separation of lithium-beryllium composite ore according to claim 1, characterized in that, The diameter of the sand discharge nozzle of the heavy medium cyclone separator in step S3 is 50-65 mm.

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