Method for efficiently extracting lithium from ore through cooperation of dressing and smelting
Through the collaborative process of heavy liquid ore dressing and fluidized roasting, the problems of complex flotation, high cost and high baking energy consumption in the existing lithium extraction process are solved, and an efficient and low-cost lithium extraction process is achieved.
Patent Information
- Application Number
- CN202311692145.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-11
- Publication Date
- 2025-06-13
AI Technical Summary
In the existing lithium extraction process, the flotation steps are complex, the cost is high, and the iron element is introduced, which leads to increased alkali consumption and reduced product quality during the subsequent lithium extraction process. At the same time, the temperature is difficult to control, the energy consumption is high, and the product needs to be ground.
The coordinated process of heavy liquid ore dressing and fluidized roasting is adopted to directly select spodumene concentrate through heavy liquid ore dressing, and the lithium concentrate is roasted into β-spentum by fluidized roasting. The roasted product is directly used to leaching and prepare lithium products without grinding.
It realizes an efficient lithium lithium extraction process without flotation and grinding, reducing production costs and energy consumption, and improving product quality and process simplicity.
Smart Images
Figure CN120138374A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of lithium extraction from ores, and specifically to an efficient ore dressing and metallurgy collaborative method for lithium extraction from ores. Background Art
[0003] Existing lithium extraction mainly includes two methods: lithium extraction from ores and lithium extraction from salt lakes.
[0004] Among them, the lithium extraction process by the ore method requires two steps of ore dressing and smelting to process the ore raw materials.
[0005] (1) Ore dressing step: In the prior art, spodumene heavy liquid ore dressing generally can only separate concentrates with a particle size of more than 0.55 mm, while flotation generally can only separate concentrates with a particle size of less than 0.15 mm. For fine-grained spodumene with a particle size of 0.15 - 0.55 mm, it needs to be finely ground and then separated by flotation.
[0006] At the same time, the flotation process requires the use of flotation reagents, has a long flotation process, complex technology and high cost of obtaining lithium concentrates. In addition, the flotation process will inevitably introduce iron elements. During subsequent lithium extraction, the introduction of iron elements will cause additional consumption of more alkali, increase the reaction cost and reduce the product quality; moreover, since the amount of iron elements introduced in each batch of concentrates is uncontrollable, the iron content of each batch of concentrates is different, and the addition amount of alkali needs to be continuously adjusted accordingly, increasing the production difficulty and being not conducive to continuous industrial production.
[0007] Therefore, how to avoid the flotation step is an urgent need for those skilled in the art.
[0008] (2) Smelting step: It is necessary to transform the naturally occurring α-spodumene into β-spodumene by high-temperature roasting.
[0009] Traditional roasting methods are all static roasting, with difficult control of roasting temperature, high energy consumption, and the ore will be sintered into blocks, which needs to be ground before being used in the subsequent leaching process.
[0010] Therefore, a roasting method that does not require subsequent grinding is an urgent need for those skilled in the art.
[0011] In summary, developing a low-energy-consumption and low-cost roasting transformation of lithium through collaborative ore dressing technology is an urgent problem that needs to be solved by those skilled in the art. Summary of the Invention
[0012] The technical problem to be solved by the present invention is to provide an efficient ore dressing and metallurgy collaborative method for lithium extraction from ores, which solves the problems existing in the prior art.
[0013] One of the purposes of the present invention is to solve the problem that the lithium concentrate needs to be ground after roasting;
[0014] The second object of the present invention is to solve the problem that fine-grained lithium ore with a particle size of 0.15 - 0.55 mm needs to be ground in advance and then flotation, and it will uncontrollably introduce iron elements.
[0015] The present invention discloses an efficient ore dressing and metallurgy collaborative lithium extraction method from ore, including the following steps:
[0016] S1. Select spodumene concentrate from the screened spodumene raw ore with a particle size of 0.15 - 0.55 mm by using heavy liquid separation.
[0017] S2. Roast the spodumene concentrate selected in step S1 by using fluidized bed roasting.
[0018] S3. Use the roasted product in step S2 directly for leaching to prepare lithium products without grinding.
[0019] Further, by mass fraction, in the spodumene raw ore in step S1, the converted Li 2 O content is 0.8% - 1.5%.
[0020] Further, the density of the heavy liquid in step S1 is 2.8 - 3.0 g / cm 3 .
[0021] Further, the fluidized bed roasting in step S2 includes the following steps:
[0022] S21. Preheat the lithium concentrate to 800 - 900 °C.
[0023] S22. Add the product processed in step S21 to the upper part of the sieve plate of the roasting equipment. The filling diameter-height ratio of the lithium concentrate is 1:0.1 - 1:10. Control the temperature at 1050 - 1150 °C. Inlet air at the bottom of the sieve plate. Adjust the gas flow rate to 0.01 - 5 m / s so that the boiling height of the concentrate is 1 - 10 times the static height, and the holding time of the concentrate is 1 - 10 min.
[0024] Preferably, the sieve plate aperture in step S22 is 0.1 - 1 mm.
[0025] Preferably, step S3 includes the following steps:
[0026] S31. React β-lithium concentrate with soda ash under heating and pressurization conditions. After cooling, directly introduce carbon dioxide to obtain a mixed slurry of lithium bicarbonate solution and leaching residue in one step.
[0027] S32. Obtain lithium bicarbonate solution after solid-liquid separation and impurity removal of the mixed slurry.
[0028] S33. Thermally decompose the lithium bicarbonate solution by negative pressure ultrasonic to obtain lithium carbonate.
[0029] S34. Directly obtain battery-grade lithium carbonate after solid-liquid separation and drying.
[0030] Preferably, the temperature in step S1 is 205 - 235 °C, and more preferably, the temperature is 225 °C.
[0031] Preferably, the pressure in step S1 is 2.4 - 3.4 MPa, and more preferably, the pressure is 3.0 MPa.
[0032] Further, the pressure of introducing carbon dioxide in step S31 is not greater than 0.6 MPa
[0033] Further, step S32 further includes an impurity removal step, and the impurity removal step adopts at least one of resin impurity removal and reagent impurity removal.
[0034] Preferably, the ultrasonic frequency in step S33 is 24 kHz.
[0035] Preferably, the negative pressure in step S33 is -0.08 Mpa.
[0036] Preferably, the pyrolysis temperature in step S33 is 79 °C.
[0037] It should be particularly noted that all static calcinations will agglomerate or form rings in the equipment. During the fluidized bed calcination process, the particle size of the raw material will directly affect the result. If the particle size is too small or too light, the primary recovery rate will be reduced, and the load of the dust collection device and the cost of secondary calcination will be increased additionally; if the particle size is too large or too heavy, the boiling effect is poor and agglomeration and ring formation will occur. Through experiments, it is found that the optimal effect is exactly in the particle size range of 0.15 - 0.55 mm.
[0038] The beneficial effects of the present invention are as follows:
[0039] 1. Make full use of the selection of the particle size of the raw material to ensure a relatively high concentrate grade and increase the output;
[0040] 2. Do not require grinding, no flotation process, no pollution of flotation reagents, and no introduction of uncontrollable iron elements;
[0041] 3. Make full use of the superiority of the appropriate particle size of the ore powder after heavy liquid separation, directly adopt fluidized bed calcination for transformation, and there is no agglomeration or ring formation after calcination, and no grinding is required;
[0042] 4. The process is short and the cost is low (no grinding and flotation are required in the beneficiation step, and no agglomeration and grinding are required in the smelting step). Description of the Drawings
[0043] Figure 1 It is the effect diagram of static calcination experiments (Figure (a) is Comparative Example 1, Figure (b) is Comparative Example 2, Figure (c) is Comparative Example 3, Figure (d) is Comparative Example 4, Figure (e) is Comparative Example 5);
[0044] Figure 2 It is the effect diagram of dynamic roasting experiment (Figure (a) is Comparative Example 7, Figure (b) is Example 1, Figure (c) is Example 2, Figure (d) is Example 3, and Figure (e) is Comparative Example 6);
[0045] Figure 3 It is the effect diagram of dynamic roasting (Figure (a) is Example 2, and Figure (b) is Comparative Example 7) Specific implementation manners
[0046] The following further describes the specific implementation manners of the present invention in conjunction with embodiments. The following embodiments are only used to more clearly illustrate the technical embodiments of the present invention and cannot be used to limit the protection scope of the present invention.
[0047] Example 1
[0048] An efficient ore lithium extraction method with coordinated ore dressing and metallurgy includes the following steps:
[0049] S1. Select spodumene concentrate from spodumene raw ore with a particle size of 0.27 - 0.55 mm obtained by screening by means of heavy liquid separation; the density of the heavy liquid is 2.8 - 3.0 g / cm 3 , in the spodumene raw ore, the converted Li 2 O content is 0.8% - 1.5%; after heavy liquid separation, the converted Li 2 O content in the spodumene concentrate is 4.5% - 6.0%;
[0050] S2. Roast the spodumene concentrate selected in step S1 by means of fluidized bed roasting; the fluidized bed roasting includes the following steps:
[0051] S21. Preheat the spodumene concentrate to 800 - 900 °C;
[0052] S22. Add the material processed in step S21 to the upper part of the sieve plate of the roasting equipment. The aperture of the sieve plate is 0.1 - 1 mm, and the ratio of the packing diameter to the height of the spodumene concentrate is 1:0.1 - 1:10. Control the temperature at 1050 - 1150 °C, introduce gas at the bottom of the sieve plate, and adjust the gas flow rate to 0.01 - 5 m / s so that the boiling height of the concentrate is 1 - 10 times the static height, and the heating time of the concentrate is 1 - 10 min.
[0053] S3. Directly use the roasted product in step S2 for leaching to prepare lithium products without grinding.
[0054] Examples 2 - 3
[0055] The difference between Examples 2 - 3 and Example 1 is only that the particle size of the spodumene raw ore selected in step S1 is different. Among them, Example 2 selects a particle size of 0.18 - 0.27 mm, and Example 3 selects a particle size of 0.15 - 0.18 mm.
[0056] To further illustrate the beneficial effects of the present invention, the following Comparative Examples 1 to 7 are specifically set up:
[0057] Comparative Examples 1 - 5
[0058] In Comparative Examples 1 - 5, the particle size and the roasting method are different from those in Example 1. The specific differences are as follows:
[0059] Table 2 Comparison Table of Operating Parameters between Comparative Examples and Examples
[0060]
[0061] It can be seen from the above comparison (Table 2) that fluidized roasting does not cause caking and does not require grinding.
[0062] Next, we set up comparative examples to analyze the influence of particle size selection on the effect:
[0063] Comparative Examples 6 - 7
[0064] In Comparative Examples 6 - 7, only the particle size is different from that in Example 1. The specific differences are as follows:
[0065] Table 3 Comparison Table of Operating Parameters between Comparative Examples and Examples
[0066] Group Roasting method Temperature (°C) Particle size (mm) Primary recovery rate (%) Phenomenon Example 1 Fluidized roasting 1100 0.27～0.55 93.76 Loose, no grinding required Example 2 Fluidized roasting 1100 0.18～0.27 92.13 Loose, no grinding required Example 3 Fluidized roasting 1100 0.15～0.18 85.53 Loose, no grinding required Comparative Example 6 Fluidized roasting 1100 Less than 0.15 65.67 Loose, no grinding required
[0067] It can be known from the comparison in Table 3 that too small a particle size will cause a large amount of raw materials to be blown out with the air during the fluidized roasting process, resulting in too low a primary recovery rate and the need for secondary recovery, which increases the production cost.
[0068] Table 4 Dynamic Heights of Different Particle Sizes
[0069] Group Particle size (mm) Gas flow rate (L / min) Dynamic height difference (cm) Example 1 0.27～0.55 35 0.9 Example 2 0.18～0.27 35 7.0 Example 3 0.15～0.18 35 10.3 Comparative Example 6 Less than 0.15 35 22.9 Comparative Example 7 0.55～1.18 35 0
[0070] Table 5 Comparison Table of Leaching Rates between Comparative Examples and Examples
[0071]
[0072] It can be known from the comparison in Table 4 that too large a particle size will cause an increase in the air flow rate required during the fluidized roasting process, and even make it impossible to blow. This leads to a reduction in reaction efficiency and an increase in production cost.
[0073] Based on the above comprehensive analysis (Table 5), the best effect of fluidized roasting is achieved when the particle size is in the range of 0.15 - 0.55 mm. In addition, during the ore dressing process, ores with a particle size below 0.15 mm need to be processed by flotation, and two adverse factors will be brought about during the flotation process:
[0074] 1. Further grinding is required, which will result in too small a particle size, and subsequent roasting will cause caking and require grinding.
[0075] 2. Flotation reagents need to be added, which will cause pollution and increase production costs at the same time.
[0076] 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 foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and 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. An efficient ore lithium extraction method combining ore dressing and metallurgy, characterized in that, it comprises the following steps: S1. Select spodumene concentrate from the screened spodumene raw ore with a particle size of 0.15 - 0.55 mm by heavy liquid ore dressing; S2. Roast the spodumene concentrate selected in step S1 by fluidized bed roasting; S3. Use the roasted product in step S2 directly for leaching to prepare lithium products without grinding.
2. The efficient ore lithium extraction method combining ore dressing and metallurgy according to claim 1, characterized in that, In terms of mass fraction, in the spodumene raw ore described in step S1, the converted Li 2 O content is 0.8% to 1.5%.
3. The efficient ore lithium extraction method combining ore dressing and metallurgy according to claim 1, characterized in that, The density of the heavy liquid described in step S1 is 2.8 - 3.0 g / cm 3 .
4. The efficient ore lithium extraction method combining ore dressing and metallurgy according to claim 1, characterized in that, The fluidized bed roasting in step S2 comprises the following steps: S21. Preheat the lithium concentrate to 800 - 900 °C; S22. Add the ore powder treated in step S21 to the upper part of the sieve plate of the roasting equipment. The filling diameter - height ratio of the lithium concentrate is 1:0.1 - 1:
10. Control the temperature at 1050 - 1150 °C, introduce gas at the bottom of the sieve plate, adjust the gas flow rate to 0.01 - 5 m / s so that the boiling height of the concentrate is 1 - 10 times the static height, and keep the temperature for 1 - 10 min.
5. The efficient ore lithium extraction method combining ore dressing and metallurgy according to claim 4, characterized in that, the aperture of the sieve plate in step S22 is 0.1 - 1 mm.