Ball milling-ultrasonic green leaching method for salt lake sedimentary clay lithium ore

Abstract

The invention relates to the technical field of lithium resource development, in particular to a ball milling-ultrasonic green leaching method for salt lake sedimentary clay lithium ore. The invention discloses a ball milling-ultrasonic green leaching method for salt lake sedimentary clay lithium ore. The method comprises the following steps: S1, primarily crushing the ore and then drying; s2, the dried minerals are subjected to plasma ball milling activation treatment; and S3, the minerals subjected to plasma ball milling activation are soaked in water, ultrasonic leaching is conducted, filtering is conducted after leaching is completed, and supernate, namely a leaching solution, is obtained. According to the ball milling-ultrasonic green leaching method for the salt lake sedimentary clay lithium ore, high-temperature roasting is not needed, the production temperature of the whole process of the technology does not exceed 100 DEG C, energy consumption is low, no acid or alkali is involved, and efficient selective leaching of lithium is achieved through water leaching.

Description

Technical Field

[0001] The invention relates to the technical field of lithium resource development, and in particular to a ball milling-ultrasonic green leaching method for salt lake sedimentary clay lithium ore. Background Art

[0002] At present, global lithium resource development is mainly aimed at salt lake brine and hard rock deposits. In terms of salt lake lithium resource development, due to the generally low grade of salt lake lithium resources and complex systems, complex processes need to be designed separately, resulting in the development of salt lake lithium resources having shortcomings such as long production cycle, high technical threshold, and high environmental pressure. For solid lithium resources, the current lithium leaching process is the roasting method and acid leaching process developed for spodumene and lithium mica. Taking the roasting process of spodumene as an example, the process first requires high-temperature roasting of spodumene to convert the chemically inert α-spodumene into the more active β-spodumene. In order to achieve a higher leaching rate through ion exchange, producers often add NaSO 4 The process is to roast with single or multiple auxiliary agents, and then treat the roasted product with water leaching to obtain a lithium-containing leachate. In order to obtain high-purity products such as lithium carbonate, the leachate needs to be purified, impurities removed, and lithium concentrated. Although this process is highly applicable to lithium ore, high-temperature roasting consumes a lot of energy and produces a lot of waste gas during the production process, which places higher demands on environmental protection. In addition, companies producing lithium carbonate are faced with the problem of storage and disposal of lithium extraction waste residues. Summary of the invention

[0003] The purpose of the present invention is to propose a ball milling-ultrasonic green leaching method for salt lake sedimentary clay lithium ore in view of the above-mentioned shortcomings of the prior art.

[0004] A ball milling-ultrasonic green leaching method for salt lake sedimentary clay lithium ore of the present invention comprises the following steps:

[0005] S1. Preliminary crushing and drying of salt lake sedimentary clay lithium ore;

[0006] S2, performing plasma ball milling activation treatment on the dried salt lake sedimentary clay lithium ore;

[0007] S3, immersing the plasma ball-milled activated mineral into water, performing ultrasonic leaching, filtering after the leaching, and obtaining a supernatant, which is the leaching solution.

[0008] Furthermore, in step S1, the salt lake sedimentary clay lithium ore is initially crushed to a particle size of less than 25 mm, and dried at 60-100° C. for more than 18 hours.

[0009] Furthermore, in step S2, the mass ratio of ball ore is 5-50:1.

[0010] Furthermore, in step S2, the ball-ore mixture occupies no more than 50% of the volume of the ball mill tank, and the rotation speed is 400-1500 r / min.

[0011] Furthermore, the discharge power is not less than 800w, and the time is 10-120min.

[0012] Furthermore, the ultrasonic frequency is not less than 20 khz.

[0013] Furthermore, the solid-liquid ratio is 1:5-20.

[0014] Furthermore, the leaching temperature is 20-100°C, and the leaching time is 30-240 minutes.

[0015] The present invention is directed to a new type of clay lithium ore, namely, salt lake sedimentary clay lithium ore. This type of salt lake sedimentary clay lithium ore is formed by the disintegration and deposition of salt lake and surrounding rocks during weathering to form clay minerals, and then through evaporation and concentration, the salts crystallized from the salt lake react with clay minerals to form new clay minerals. The characteristic minerals are mainly clay lithium ore such as montmorillonite and illite, and most of the lithium exists in the form of interlayer adsorbed lithium in montmorillonite and plagioclase minerals. Clay lithium ore such as montmorillonite has a typical layered structure, and the layers are combined by weak ionic bonds or intermolecular forces. This structure is relatively easy to change when subjected to external forces. During the plasma ball milling process, high-intensity mechanical impact force acts on the surface of clay particles. As the ball milling time increases, the impact force will gradually penetrate into the interlayer, and cooperate with the high-energy ion action of plasma to further promote structural dislocation, slippage and even peeling, resulting in the destruction of the orderliness of the layered structure, so that the interlayer adsorbed lithium and part of the structural lithium are exposed, which is conducive to mild process extraction. Salt lake sedimentary clay lithium ores are usually rich in sodium salts. In the solution, the adsorption force of clay on hydrated sodium ions is greater than that on hydrated lithium ions. Lithium extraction can be achieved by utilizing the principle of ion exchange. Ultrasonic technology is further introduced to utilize the cavitation effect of ultrasonic technology to peel off the clay layer and the high energy effect to promote ion movement to achieve efficient extraction in a short time.

[0016] The ball milling-ultrasonic green leaching method for salt lake sedimentary clay lithium ore of the present invention does not require high-temperature roasting. The production temperature of the whole process of the technology does not exceed 100°C, the energy consumption is small, no acid or alkali is involved, and the efficient selective leaching of lithium is achieved by water leaching. The technology is energy-saving and environmentally friendly, with a simple production process, low cost, and simple leaching solution components, and has a strong application prospect.

[0017] Plasma ball milling-ultrasonic technology can be used to efficiently extract salt lake sedimentary clay lithium ore. The leaching stage can be completed within 30 minutes, and the extraction rate can reach more than 70%, greatly improving production efficiency. The whole process does not involve high temperature, additives, strong acids and alkalis, is environmentally friendly and pollution-free, and has low cost.

[0018] Since the present invention does not involve strong acid, strong alkali, and auxiliary agent roasting, high-priced elements such as iron and aluminum in the clay lithium ore will not be leached, so the ion composition in the leachate is relatively simple, which is convenient for subsequent impurity removal and purification work. In addition, after the clay lithium ore is extracted, only the physical properties such as morphology and particle size are changed, which is pollution-free and in line with the concept of environmentally friendly production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The maps-min test results of a clay sample from a certain place in Xinjiang implemented by the technical solution of this embodiment;

[0020] Figure 2 This is the XRD test result of salt lake sedimentary clay lithium ore;

[0021] Figure 3 This is the XRD comparison diagram of salt lake sedimentary clay lithium ore under different plasma ball milling times;

[0022] Figure 4 This is the FTIR comparison diagram of salt lake sedimentary clay lithium ore under different plasma ball milling times;

[0023] Figure 5 This is a comparison of the effects of water immersion of salt lake sedimentary clay lithium ore at different temperatures;

[0024] Figure 6 The lithium leaching rate of salt lake sedimentary clay after plasma ball milling treatment for different lengths of time and immersion in water at 40°C for 2 hours;

[0025] Figure 7 It is a comparison chart of lithium leaching rate of salt lake sedimentary clay lithium ore after water leaching at 40°C and ball milling for 90 minutes, and the comparison chart of lithium leaching rate of salt lake sedimentary clay lithium ore after water leaching at 40°C and ball milling for 90 minutes under ultrasonic leaching at 40°C;

[0026] Figure 8 It is the leaching rate of each ion of the clay lithium resource in Kushui Lake and the ion concentration in the leachate. DETAILED DESCRIPTION

[0027] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0028] Example 1

[0029] This example conducts technical verification on the clay lithium mine in the Kushui Lake area of ​​West Kunlun, Xinjiang.

[0030] First, take 100g of the original ore sample and dry it in an oven at 80℃ for 24h. After drying, mix the ore thoroughly. Take 10g of the sample and place 200g of mixed steel balls of different particle sizes in a stainless steel ball mill. Use a plasma ball mill for ball milling. The parameters are adjusted to a speed of 1500r / min, a discharge power of 1350w, and a time of 90min.

[0031] After the ball milling is completed, 2 g of the treated sample is placed in a glass beaker, and 20 ml of water is added to seal the beaker for later use. The ultrasonic machine parameters are set as follows: frequency: 40 kHz, temperature: 40°C, time: 30 min. After the leaching is completed, it is filtered to obtain the supernatant, which is the leaching solution. After testing, the lithium extraction rate of this process reaches 80%.

[0032] Example 2

[0033] The ball milling time was changed, and the other steps were the same as in Example 1.

[0034] Example 3

[0035] The water immersion temperature was changed, and the other steps were the same as those in Example 1.

[0036] Comparative Example 1

[0037] The minerals are subjected to water leaching only.

[0038] Comparative Example 2

[0039] The mineral after ball milling for 90 min was soaked in water at 40° C., and the other steps were the same as in Example 1.

[0040] See attached Figure 1 Table 1 and Table 1 are the maps-min test results of a clay sample from a certain place in Xinjiang implemented according to the technical solution of this embodiment, which clearly show us that the main phases of the salt lake sedimentary clay lithium ore are montmorillonite, quartz, plagioclase, etc.

[0041] Table 1

[0042]

[0043] Figure 2 This is the XRD test result of salt lake sedimentary clay lithium ore. Figure 2 The main phase composition information of the mineral can be obtained. Combined with the results in Table 1, it can be seen that the main phases of the clay mineral are composed of quartz and rock salt. The characteristic clay minerals are montmorillonite, plagioclase and illite. Lithium mainly exists in the interlayers or structures of common clay characteristic minerals such as montmorillonite, plagioclase and illite.

[0044] Figure 3 The XRD comparison diagram of salt lake sedimentary clay lithium ore under different plasma ball milling times. Figure 3It can be seen that during the ball milling process, the peak intensity of quartz and rock salt did not change significantly, and the main phases of the final product after ball milling were also quartz and rock salt. Compared with the original phase, the increase in ball milling intensity caused the loss of the crystalline phase of montmorillonite, resulting in an increase in the degree of amorphization. The structures of other clay minerals are relatively stable compared to montmorillonite, but the structure is also affected to a certain extent. Some peaks of illite have weakened, and the disappearance of the 54° peak proves that long-term ball milling has caused plagioclase to become amorphous, proving that its structure has been destroyed.

[0045] Figure 4 This is a FTIR comparison chart of salt lake sedimentary clay lithium ore under different plasma ball milling times, which can further verify that the extension of ball milling time destroys the structure of plagioclase and montmorillonite, exposes the interlayer adsorbed water, and the structural water is also exposed to a certain extent, proving the destruction of the structure.

[0046] Figure 5 This is a comparison chart of the effects of water leaching of salt lake sedimentary clay lithium ore at different temperatures. It can be seen from the figure that at 50°C, the lithium leaching rate is relatively higher.

[0047] Figure 6 is the lithium leaching rate of salt lake sedimentary clay after plasma ball milling for different lengths of time and immersion in water at 40℃ for 2h. Figure 5 It can be seen that the lithium leaching rate increases with the appropriate extension of the ball milling time. After 90 minutes of ball milling, the lithium leaching rate is basically stable.

[0048] Figure 7 This is a comparison chart of lithium leaching rates of salt lake sedimentary clay lithium ore after water leaching at 40°C, water leaching at 40°C, and ultrasonic leaching at 40°C for 90 minutes of salt lake sedimentary clay lithium ore after ball milling. It can be seen that the ball milling-ultrasonic process can not only significantly improve the lithium leaching rate, but also greatly speed up the leaching efficiency, shorten the production time and reduce energy consumption.

[0049] Figure 8 According to the leaching rate of each ion of the bitter lake clay lithium resource and the ion concentration in the leachate carried out according to the technical solution of this embodiment, it can be seen that the leaching rate of high-valent ions is low, and the ratio of impurity ions to lithium ions in the leachate is much lower than that of the traditional process, which can not only simplify the subsequent production process, but also reduce the lithium loss in the impurity removal process.

[0050] For matters not mentioned above, the prior art applies.

[0051] Although some specific embodiments of the present invention have been described in detail through examples, those skilled in the art should understand that the above examples are for illustration only and are not intended to limit the scope of the present invention. Those skilled in the art to which the present invention belongs may make various modifications or supplements to the specific embodiments described or replace them in a similar manner, but they will not deviate from the direction of the present invention or exceed the scope defined by the attached claims. Those skilled in the art should understand that any modifications, equivalent substitutions, improvements, etc. made to the above embodiments based on the technical essence of the present invention should be included in the protection scope of the present invention.

Claims

1. A ball milling-ultrasonic green leaching method for salt lake sedimentary clay lithium ore, characterized in that: The steps include: S1. Preliminary crushing and drying of salt lake sedimentary clay lithium ore; S2, performing plasma ball milling activation treatment on the dried salt lake sedimentary clay lithium ore; S3, immersing the plasma ball-milled activated mineral into water, performing ultrasonic leaching, filtering after the leaching, and obtaining a supernatant, which is the leaching solution.

2. The ball milling-ultrasonic green leaching method for salt lake sedimentary clay lithium ore according to claim 1, characterized in that: In step S1, the salt lake sedimentary clay lithium ore is initially crushed to a particle size of less than 25 mm and dried at 60-100° C. for more than 18 hours.

3. The ball milling-ultrasonic green leaching method for salt lake sedimentary clay lithium ore according to claim 1, characterized in that: In step S2, the mass ratio of ball to ore is 5-50:

1.

4. The ball milling-ultrasonic green leaching method for salt lake sedimentary clay lithium ore according to claim 1, characterized in that: In step S2, the ball-ore mixture occupies no more than 50% of the volume of the ball mill tank, and the rotation speed is 400-1500r / min.

5. The ball milling-ultrasonic green leaching method for salt lake sedimentary clay lithium ore according to claim 1, characterized in that: Discharge power: not less than 800w, time 10-120min.

6. The ball milling-ultrasonic green leaching method for salt lake sedimentary clay lithium ore according to claim 1, characterized in that: The ultrasonic frequency is not less than 20khz.

7. The ball milling-ultrasonic green leaching method for salt lake sedimentary clay lithium ore according to claim 1, characterized in that: The solid-liquid ratio is 1:5-20.

8. The ball milling-ultrasonic green leaching method for salt lake sedimentary clay lithium ore according to claim 1, characterized in that: The leaching temperature is 20-100°C and the leaching time is 30-240min.

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