Method for directly preparing ceramic-grade lithium concentrate by using dense medium

Abstract

The invention relates to the technical field of ore lithium extraction, in particular to a method for directly preparing ceramic-grade lithium concentrate by using a dense medium. The method has the beneficial effects that a high-added-value product, namely the ceramic-grade lithium concentrate, with the grade higher than 7% 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] The present invention relates to the technical field of lithium extraction from ores, and in particular to a method for directly preparing ceramic-grade lithium concentrate by utilizing a heavy medium. Background Art

[0002] Lithium, a rare element crucial for promoting modernization and the development of science and technology, is a new energy source and strategic resource with the greatest potential for development. It is widely used in a wide range of fields, including high-energy lithium batteries, the rubber industry, aerospace, ceramics, lasers, medicine, welding, explosives, cement, smelting, and new energy. It is known as the "energy metal of the 21st century." Many countries, driven by economic development and national security considerations, have designated lithium and its high-purity lithium salts as strategic reserves and are conducting extensive research into their application.

[0003] The existing lithium extraction methods mainly include the ore lithium extraction method using lithium ore as raw material and the salt lake lithium extraction method using lithium-containing salt lake as raw material.

[0004] Among them, the ore extraction process is currently the main method. The mined ore needs to be beneficiated into high-grade concentrate before it can enter the smelting step.

[0005] The beneficiation process for lithium ore is divided into heavy medium beneficiation and flotation. Heavy medium beneficiation utilizes the density differences of different components in the ore to separate them. Its advantages are low beneficiation costs and zero pollution.

[0006] The principle of heavy medium separation is to physically separate components by utilizing density differences. The density of the heavy medium should be between the density of the heavy and light components. For components with similar densities, heavy medium separation is often unable to directly produce a concentrate.

[0007] The traditional view is that the density of lithium-beryllium composite ore is usually 2.7g / cm 3 The density of lithium concentrate is about 3.0-3.2g / cm 3 , the density of beryllium concentrate is 2.8~3.0g / cm 3 The density of impurities such as feldspar and quartz is 2.6 to 2.8 g / cm 3 Since the three components to be separated have similar densities and overlap with each other, it is impossible to directly separate and obtain concentrate using the heavy medium method.

[0008] In the existing technology, the density of 2.5 to 3.2 g / cm is usually used. 3 The heavy medium used to pre-separate the raw ore can only concentrate the lithium ore to a grade of less than 4% (calculated as Li2O, m / m%). Subsequent flotation and other operations are required to obtain qualified lithium concentrate.

[0009] Compared to flotation, heavy medium separation offers the advantages of low cost and zero pollution. Therefore, using heavy medium separation to separate lithium-beryllium complex ores, directly obtaining lithium concentrate (grade above 5%, calculated as Li₂O, m / m%), and reducing flotation yields is an urgent challenge for those skilled in the art.

[0010] Spodumene is divided into three categories according to its use, chemical composition and smelting process requirements: chemical spodumene, ceramic spodumene and low-iron spodumene.

[0011] Ceramic Industry: Adding spodumene to ceramic bodies can improve the strength, density, acid resistance, and thermal shock resistance of ceramic products, while reducing water absorption and linear shrinkage. Adding an appropriate amount of spodumene to glazes and frits can reduce the product's thermal expansion coefficient, improve high-temperature fluidity, reduce viscosity, and enhance the glaze's whiteness, gloss, hardness, and corrosion resistance, improving product quality while also making the finished product aesthetically pleasing, durable, and with a low scrap rate.

[0012] Among them, ceramic-grade spodumene is the most expensive and has the highest grade requirements. How to directly select and prepare ceramic-grade spodumene concentrate from lithium-beryllium composite ore at a lower cost has always been an urgent desire of those skilled in the art. Summary of the Invention

[0013] The technical problem to be solved by the present invention is to provide a method for directly preparing ceramic-grade lithium concentrate using heavy media, which solves the problems existing in the prior art.

[0014] The purpose of the present invention is to solve the problem of directly obtaining lithium concentrate using a heavy medium method;

[0015] The present invention discloses a method for directly preparing ceramic-grade lithium concentrate by using a heavy medium, comprising the following steps:

[0016] S1, broken;

[0017] S2, screening;

[0018] S3, mineral processing;

[0019] The S3 step adopts a heavy medium beneficiation process, using a pressureless heavy medium cyclone for beneficiation, and the density of the heavy medium used is 2.26-2.45 g / cm 3 , the specific steps are as follows:

[0020] S31, introducing the product of step S2 into a first heavy medium cyclone to obtain heavy medium lithium tailings and first heavy medium lithium middlings;

[0021] S32. Introducing the first heavy medium lithium middlings obtained in step S32 into a second heavy medium cyclone to obtain heavy medium lithium middlings and heavy medium lithium concentrate; the heavy medium lithium concentrate is a ceramic grade lithium concentrate.

[0022] Preferably, the particle size of the lithium ore obtained by screening in step S2 is -6.0mm+0.5mm.

[0023] Furthermore, the frequency of the heavy medium cyclone in step S3 is 22 to 30 Hz.

[0024] Preferably, the diameter of the sand settling nozzle of the heavy medium cyclone in step S3 is 45 mm.

[0025] The beneficial effects of the present invention are:

[0026] 1. Directly obtain high-value-added products with a grade higher than 7% - ceramic-grade lithium concentrate through heavy medium beneficiation;

[0027] 2. Realized the separation of lithium and beryllium;

[0028] 3. Reduced flotation volume and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Flowchart. DETAILED DESCRIPTION

[0030] The specific implementation methods of the present invention will be further described below in conjunction with examples. The following examples are only used to more clearly illustrate the technical embodiments of the present invention and are not intended to limit the scope of protection of the present invention.

[0031] Sources of raw materials for lithium-beryllium composite ore:

[0032] The lithium ore is selected from the Dahongliutan lithium-beryllium polymetallic mine in Hotan County, Xinjiang Uygur Autonomous Region. Its composition is as follows:

[0033] Table 1 Ore raw material composition

[0034] Components (calculated as metal oxides) Content (m / m%) <![CDATA[Li2O]]> 1.40 BeO 0.038

[0035] Example 1

[0036] A method for directly preparing ceramic-grade lithium concentrate using heavy medium comprises the following steps:

[0037] S1, broken;

[0038] S2, screening;

[0039] The particle size of the lithium ore obtained by screening is -6.0mm+0.5mm;

[0040] S3, mineral processing;

[0041] The S3 step adopts a heavy medium beneficiation process and adopts a non-pressure heavy medium cyclone for beneficiation. The frequency of the heavy medium cyclone is 30 Hz, and the diameter of the sand settling nozzle of the heavy medium cyclone is 45 mm.

[0042] The density of the heavy medium used is 2.45g / cm 3 ;

[0043] The specific steps are as follows:

[0044] S31, introducing the product of step S2 into a pressureless three-product heavy medium cyclone to obtain heavy medium lithium tailings, heavy medium lithium middlings and heavy medium lithium concentrate;

[0045] The heavy medium lithium concentrate is directly used for smelting; the heavy medium lithium middlings enter the subsequent flotation step for further purification and separation of lithium and beryllium.

[0046] See attached for the flow chart Figure 1

[0047] Examples 2 to 9

[0048] The difference between Examples 2 to 9 and Example 1 is only in the operating parameters. Specific example parameters are shown in Table 2 below:

[0049] Table 2 Example operating parameters

[0050]

[0051] The products after beneficiation in the above embodiment were analyzed, and the results shown in Tables 3 and 4 below were obtained:

[0052] Table 3 Experimental results of example 1

[0053]

[0054]

[0055] Table 4 Experimental results of example 2

[0056]

[0057] From the above test data, we can know that:

[0058] The method of the present invention achieves the purpose of obtaining ceramic-grade lithium concentrate (with a grade greater than 7%) by directly beneficiating with heavy media.

[0059] In order to further illustrate the beneficial effects of the present invention, the following comparative examples are provided:

[0060] Comparative Examples 1 to 4

[0061] Comparative Examples 1 to 4 are compared with the embodiment, mainly in that the operating parameters are adjusted. The specific operations are shown in Table 5 below:

[0062] Table 5 Comparative Example Operating Parameters

[0063]

[0064] The products after beneficiation in the comparative example were analyzed, and the results shown in Tables 6 and 7 below were obtained:

[0065] Table 6 Comparative Example Experimental Results Table-1

[0066]

[0067] Table 7 Comparative Example Experimental Results Table-2

[0068]

[0069]

[0070] From the above comparative examples, it can be seen that:

[0071] 1. As can be seen from Comparative Example 4, ceramic-grade lithium concentrate cannot be obtained if the density of the heavy medium is too low;

[0072] 2. Comparative Examples 1 to 3 show that there is a correlation between the selection of heavy medium density and the feeding frequency, and the effect of this correlation is unexpected.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements 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 directly preparing ceramic-grade lithium concentrate using heavy media, characterized in that: The steps include: S1, broken; S2, screening; S3, mineral processing; The S3 step adopts a heavy medium beneficiation process, using a non-pressure heavy medium cyclone for beneficiation, and the density of the heavy medium used is 2.26-2.45 g / cm 3 , the specific steps are as follows: S31. Introducing the product of step S2 into a pressureless three-product heavy medium cyclone to obtain heavy medium lithium tailings, heavy medium lithium middlings and heavy medium lithium concentrate; the heavy medium lithium concentrate is ceramic grade lithium concentrate.

2. The method for directly preparing ceramic-grade lithium concentrate using heavy medium according to claim 1, characterized in that: The particle size of the lithium ore obtained by screening in step S2 is -6.0mm+0.5mm.

3. The method for directly preparing ceramic-grade lithium concentrate using heavy medium according to claim 1, characterized in that: The frequency of the heavy medium cyclone in step S3 is 22 to 40 Hz.

4. The method for directly preparing ceramic-grade lithium concentrate using heavy medium according to claim 1, characterized in that: The diameter of the sand settling nozzle of the heavy medium cyclone in step S3 is 45 mm.

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