Method for processing ore containing lithium

Abstract

The present invention relates to a method for processing an ore containing lithium, the method comprising the steps of: calcining an ore containing lithium to obtain a calcined ore; bringing a heat medium into contact with the calcined ore to allow the heat medium to acquire thermal energy through heat exchange; separating, from the calcined ore, the heat medium having the acquired thermal energy; and utilizing the separated heat medium in a process requiring thermal energy.

Description

Method for processing lithium-containing ore

[0001] The present invention relates to a method for treating lithium-containing ore.

[0002] This application claims priority to Korean Patent Application No. 10-2024-0190719, filed on December 19, 2024, the entire contents of which are incorporated herein by reference.

[0003] Lithium is a material for secondary batteries, and its importance as a power source for hybrid and electric vehicles has recently emerged. The market size is expected to grow more than 50 to 100 times compared to the current level in the future.

[0004] Generally, lithium can be extracted from lithium-containing ores, and within the lithium-containing ores, lithium exists as a mineral form called LiAlSi2O6 (spodumene). Spodumene is a naturally occurring α-spodumene mineral composed of lithium aluminum silicate LiAl(SiO3)2. To recover lithium from spodumene, an acid leaching process is generally performed.

[0005] However, naturally occurring α-spodumene is not easily acid-leached due to the high stability of its crystal structure. To acid-leach the valuable metals from spodumene, α-spodumene is heated above 850°C to convert it into β-spodumene, after which the acid leaching process is carried out. β-spodumene (LiAlSi2O6) is produced by the sulfuric acid roasting process to remove the Li from the ore. + H dissociated from sulfuric acid at the ion site + Ion-exchanged with ions, and ion-exchanged Li + SO4 ions dissociated 2- It can combine with ions, and a precipitation reaction proceeds to precipitate as lithium sulfate (Li2SO4).

[0006] When the precipitated lithium sulfate (Li2SO4) is leached with water and then subjected to solid-liquid separation, lithium sulfate and a residue in the form of a solid compound remain.

[0007] There is a problem in that the moisture content of the residue in the form of solid compounds remaining after lithium extraction from lithium ore exceeds 30%, which hinders the usability of the residue. In order to utilize the residue in other processes, the moisture content must be controlled. However, moisture is present in the cracks within the residue, making it difficult to remove moisture using conventional hot air drying methods.

[0008] Accordingly, there is a need to develop a method for removing moisture from the residue to improve its usability.

[0009] One objective of the present invention is to secure thermal energy through heat exchange between a heat medium and calcined ore, and to utilize the heat medium with secured thermal energy in other processes that require thermal energy.

[0010] Another objective of the present invention is to recycle the heat medium by reintroducing it into a step of heat exchange with calcined ore after it has been utilized in another process requiring thermal energy.

[0011] A method for treating lithium-containing ore according to one embodiment of the present invention comprises: a step of calcining the lithium-containing ore to obtain calcined ore; a step of contacting a heat medium with the calcined ore to secure thermal energy of the heat medium through heat exchange; a step of separating the heat medium from the calcined ore from the heat medium in which thermal energy has been secured; and a step of utilizing the separated heat medium in a process requiring thermal energy.

[0012] The method may further include the step of obtaining roasted ore by roasting the calcined ore separated from the heat medium; and the step of obtaining residue by leaching and purifying the roasted ore.

[0013] The step of utilizing the separated heat medium in another process requiring thermal energy may include the step of bringing the separated heat medium into contact with the residue to evaporate the moisture contained in the residue.

[0014] The step of evaporating the moisture contained in the residue may involve bringing the separated heat medium into direct contact with the residue to evaporate the moisture through heat conduction.

[0015] The mixing ratio of the residue and the separated heat medium may be 1:1.5 to 1:3.

[0016] The method may further include a step of bringing the separated heat medium into direct contact with the residue to evaporate moisture through heat conduction; and a step of separating the separated heat medium from the residue from which moisture has evaporated.

[0017] The moisture content in the residue from which the above moisture has evaporated may be 5 to 25%.

[0018] The evaporation rate of the above moisture may be 1 to 3 ton / h.

[0019] In the step of contacting a heat medium with the above-mentioned calcined ore; the temperature of the above-mentioned calcined ore may be 800 to 1100℃, and the temperature of the heat medium may be 25 to 100℃.

[0020] In the step of separating the heat medium that has secured the thermal energy and the calcined ore; the temperature of the heat medium that has secured the thermal energy may be 400 to 600℃.

[0021] The heat medium after being utilized in the step of utilizing the separated heat medium in a process requiring thermal energy may be reintroduced to the step of contacting the heat medium with the calcined ore.

[0022] In the step of contacting the heat medium with the above-mentioned calcined ore, the input speed of the heat medium may be 40 to 70 ton / h.

[0023] In the step of contacting a heat medium with the above-mentioned calcined ore; the particle size of the heat medium may be 5 to 15 mm.

[0024] A method for treating lithium-containing ore, wherein the type of heat medium comprises at least one of iron beads, copper-iron beads, ceramic beads, carbon steel beads, stainless beads, chrome steel cushions, tungsten beads, and brass beads.

[0025] The sensible heat of the above calcined light may be 9,000 to 12,000 MJ / h.

[0026] The supply rate of the above calcined ore may be 15 to 30 tons / h.

[0027] The above lithium-containing ore may include one or more selected from the group consisting of spodumene, petalite, lepidolite, hectorite, eucryptite, jadarite, zinnwaldite, and amblygonite.

[0028] In one embodiment of the present invention, a heat medium that secures thermal energy using the calcined ore after calcining lithium ore can remove moisture by utilizing it in other processes that require thermal energy.

[0029] In another embodiment of the present invention, the heat transfer medium can be recycled after transferring thermal energy within the process, so it can be utilized in processes requiring thermal energy at a low cost.

[0030] FIG. 1 schematically illustrates a method for treating lithium-containing ore according to one embodiment and a comparative example of the present invention.

[0031] In this specification, terms such as first, second, and third are used to describe various parts, components, regions, layers, and / or sections, but are not limited thereto. These terms are used solely to distinguish one part, component, region, layer, or section from another part, component, region, layer, or section. Accordingly, the first part, component, region, layer, or section described below may be referred to as the second part, component, region, layer, or section without departing from the scope of the invention.

[0032] The technical terms used herein are for the reference of specific embodiments only and are not intended to limit the invention. The singular forms used herein include plural forms unless phrases clearly indicate otherwise. As used in the specification, the meaning of "comprising" specifies certain characteristics, areas, integers, steps, actions, elements, and / or components, and does not exclude the presence or addition of other characteristics, areas, integers, steps, actions, elements, and / or components.

[0033] When it is stated that one part is "above" or "on" another part, it may be directly above or on the other part, or other parts may be involved in between. In contrast, when it is stated that one part is "directly above" another part, no other parts are interposed in between.

[0034] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as generally understood by those skilled in the art to which this invention pertains. Terms defined in commonly used dictionaries are further interpreted to have meanings consistent with relevant technical literature and the present disclosure, and are not interpreted in an ideal or highly formal sense unless otherwise defined.

[0035] Also, unless otherwise specified, % means weight %, and 1 ppm is 0.0001 weight %.

[0036] In this specification, the term “combination(s) of these” described in the Markush-type expression means one or more mixtures or combinations selected from the group consisting of the components described in the Markush-type expression, and means including any one or more selected from the group consisting of said components.

[0037] Hereinafter, embodiments of the present invention are described in detail so that those skilled in the art can easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0038] Method for processing lithium-containing ore

[0039] Figure 1 schematically illustrates a method for processing lithium-containing ore.

[0040] Referring to FIG. 1, a method for treating lithium-containing ore according to one embodiment of the present invention may include the steps of calcining the lithium-containing ore, mixing the calcined ore with a heat medium for heat exchange, separating the ore and the heat medium, directly contacting the heat medium with the residue discharged from the roasting step and the leaching and purification step to transfer heat to the residue and dry it, and then separating the heat medium for recycling.

[0041] A method for treating lithium-containing ore according to the present invention includes the step of preparing lithium-containing ore.

[0042] In one embodiment of the present invention, the lithium-containing ore may comprise one or more selected from the group consisting of spodumene, petalite, lepidolite, hectorite, eucryptite, jadarite, zinnwaldite, and amblygonite.

[0043] The method for processing lithium-containing ore according to the present invention may further include the step of calcining the lithium-containing ore to obtain calcined ore and the step of contacting a heat medium with the calcined ore to secure thermal energy of the heat medium through heat exchange.

[0044] Specifically, in the step of contacting the heat medium with the calcined ore, the input speed of the separated heat medium may be 40 to 70 ton / h, and specifically 45 to 65 ton / h. If the input speed of the heat medium satisfies the above range, the contact between the residue and the heat medium is optimized, enabling efficient heat transfer and thus providing the advantage of improved energy efficiency. On the other hand, if the input speed of the heat medium is too slow, a problem of reduced productivity may occur due to an increase in the overall process time. In addition, if the input speed of the heat medium is too fast, the contact time with the residue is reduced, and sufficient heat exchange may not occur.

[0045] In addition, in the step of contacting the heat medium with the calcined ore, the particle size of the heat medium may be 5 to 15 mm, specifically 8 to 12 mm. If the particle size of the heat medium satisfies the above range, heat exchange with the residue can be efficiently carried out through direct contact between the heat medium and the residue. On the other hand, if the particle size of the heat medium is too small, the surface area of ​​the heat medium increases excessively, which may cause the heat medium to aggregate. In addition, if the particle size of the heat medium is too large, the heat transfer surface area of ​​the heat medium decreases, which may cause a problem of reduced heat transfer efficiency into the residue.

[0046] The above types of heat transfer media may include, but are not limited to, at least one of iron beads, copper-iron beads, ceramic beads, carbon steel beads, stainless beads, chrome steel beads, tungsten beads, and brass beads, and any material capable of absorbing heat from calcined ore and transferring it to a place where thermal energy is required may be used.

[0047] In addition, in the step of contacting a heat medium with the calcined ore, the temperature of the calcined ore may be 800 to 1100°C, and the temperature of the heat medium may be 25 to 100°C. Specifically, the temperature of the calcined tube may be 850 to 1050°C, and the temperature of the heat medium may be 50 to 80°C. If the temperatures of the calcined ore and the heat medium satisfy the above ranges, efficient heat transfer from the high-temperature calcined ore to the heat medium at a relatively low temperature is possible, thereby improving process efficiency. On the other hand, if the temperature of the calcined ore is too low or the temperature of the heat medium is too high, heat exchange between the calcined ore and the heat medium proceeds inefficiently, which may result in energy waste. Furthermore, if the temperature of the calcined ore is too high or the temperature of the heat medium is too low, excessive heat is transferred to the heat medium, causing excessive evaporation of moisture from the residue and a deterioration in the quality of the residue.

[0048] The sensible heat of the above-mentioned calcined ore may be 9,000 to 12,000 MJ / h, and specifically 10,000 to 11,000 MJ / h. If the above-mentioned sensible heat satisfies the above range, heat exchange with the heat medium can be properly carried out. On the other hand, if the above-mentioned sensible heat is too low, heat exchange between the calcined ore and the heat medium is insufficient, which may cause a problem where moisture does not evaporate sufficiently during residue drying. In addition, if the above-mentioned sensible heat is too high, excessive heat is transferred to the heat medium, causing excessive evaporation of moisture in the residue and resulting in a deterioration of quality.

[0049] In addition, the supply speed of the calcined ore may be 15 to 30 ton / h, specifically 20 to 25 ton / h. If the supply speed of the calcined ore satisfies the above range, the process can be operated stably, thereby preventing equipment overload. On the other hand, if the supply speed of the calcined ore is too slow, the production volume of residue may decrease, and overall production efficiency may be reduced. Furthermore, if the supply speed of the calcined ore is too fast, the equipment may be overloaded, leading to a problem of quality degradation.

[0050] The method for treating lithium-containing ore according to the present invention may include a step of separating a heat medium, from which thermal energy has been secured, from the calcined ore.

[0051] In the step of separating the heat medium that has secured the thermal energy and the calcined ore; the temperature of the heat medium that has secured the thermal energy may be 400 to 600°C, and specifically 450 to 550°C. When the temperature of the heat medium satisfies the above range, the heat medium can adequately remove moisture from the residue through direct contact with the residue. On the other hand, if the temperature of the heat medium is too low, too little heat is supplied to the residue, making it difficult to remove moisture from the residue. In addition, if the temperature of the heat medium is too high, the moisture content in the residue decreases rapidly, which may cause a problem of reduced quality of the residue.

[0052] Subsequently, the method may further include the step of obtaining roasted ore by roasting the calcined ore separated from the heat medium; and the step of obtaining residue by leaching and purifying the roasted ore.

[0053] The method for treating lithium-containing ore according to the present invention may include the step of utilizing a separated heat transfer medium in a process requiring thermal energy.

[0054] The step of utilizing the separated heat medium in another process requiring thermal energy may include the step of bringing the separated heat medium into contact with the residue to evaporate the moisture contained in the residue.

[0055] Specifically, the step of evaporating the moisture contained in the residue can evaporate the moisture through heat conduction by bringing the separated heat medium into direct contact with the residue.

[0056] The mixing ratio of the residue and the separated heat medium may be 1:1.5 to 1:3, specifically 1:2 to 1:2.5. When the above mixing ratio is satisfied, the heat medium is properly mixed with the residue, allowing for efficient heat transfer. On the other hand, if the above mixing ratio is lower than 1:1.5, a problem may arise where the amount of heat medium is insufficient, leading to reduced heat transfer efficiency. Additionally, if the above mixing ratio is higher than 1:3, an excessive amount of heat medium may increase the load on process equipment and cause energy waste, resulting in reduced economic efficiency.

[0057] Specifically, the moisture content in the residue from which the moisture has evaporated may be 5 to 25% or 10 to 20%. If the moisture content in the residue satisfies the above range, dust generation is reduced, making it easier to process and transport the residue. On the other hand, if the moisture content in the residue is too low, the residue may become excessively dry, leading to severe dust generation and making it prone to damage during handling. Additionally, if the moisture content in the residue is too high, the residue may clump together due to excessive moisture, and an additional drying step may be required, leading to increased process costs.

[0058] In one embodiment, the evaporation rate of the moisture may be 1 to 3 ton / h, specifically 1.5 to 2.5 ton / h. If the evaporation rate of the moisture satisfies the above range, it evaporates at an appropriate rate, allowing for efficient management of energy consumption and potentially reducing process operating costs. On the other hand, if the evaporation rate of the moisture is too slow, excessive moisture may remain in the residue, potentially causing problems during subsequent processing. Additionally, if the evaporation rate of the moisture is too fast, the residue may become excessively dry, leading to dust generation or physical damage and resulting in a decrease in quality.

[0059] Additionally, the method may further include a step of bringing the separated heat medium into direct contact with the residue to evaporate moisture through heat conduction; and a step of separating the separated heat medium from the residue from which moisture has evaporated.

[0060] In addition, the heat medium after being utilized in the step of utilizing the separated heat medium in a process requiring thermal energy can be reintroduced to the step of contacting the heat medium with the calcined ore.

[0061] The embodiments of the present invention will be described in more detail below through examples. However, the following examples are merely preferred embodiments of the present invention, and the present invention is not limited by the following examples.

[0062] Example 1

[0063] (Ore and steel ball mixing stage)

[0064] It is a rotary R / K type, and a steel ball at 100°C and an ore (calcined ore) at 1,000°C are fed together, and as the heat of the ore (calcined ore) is absorbed by the heat medium (steel ball), the ore (calcined ore) is cooled and the heat medium (steel ball) is heated. In addition, the ore (calcined ore) can be crushed by the heat medium (steel ball), and a separate crushing process thereafter is unnecessary.

[0065] (Calcined ore and steel ball separation stage)

[0066] The particle size of the crushed ore (calcined ore) was 1 mm or less and the size of the heat medium (steel ball) was 10 mm or more, and the heat medium (steel ball) and the ore (calcined ore) after heat exchange were easily separated using a sieve. The separated ore (calcined ore) was immediately fed into the roasting process, and the separated heat medium (steel ball) after heat exchange was fed into a dryer to dry the residue.

[0067] (Drying stage)

[0068] 60 tons of heat transfer medium (steel balls) heat-exchanged at 500℃ and 35 tons of residue containing 30% moisture were mixed, and the moisture in the residue was dried using the heat from the steel balls through direct contact. The amount of moisture contained in the residue is 10.5 tons (35 tons x 0.3), and if 2.5 tons of this is removed, the moisture content of the residue is reduced to 23%, and if an additional 2.5 tons are removed, the moisture can be reduced to 17%.

[0069] (Dried residue and steel ball separation step)

[0070] The temperature of the residue with reduced moisture content and the heat medium (steel ball) is 100℃, and the heat medium (steel ball) and residue are separated by magnetic separation or by sieving, and the separated heat medium (steel ball) can be reintroduced into the ore and steel ball mixing stage.

[0071] Cp(kJ / ton)△T(Tin-Tout)M(ton / h)△H(kJ / h) Ore 830500(1000→500℃)2510,375,000 Heat Medium (Steel Ball) 420400(100→500℃)6010,080,000 Water 4200100(25→100℃)2.51,050,000 Vapor heat 5,650,000

[0072] Referring to Table 1, it can be confirmed that the sensible heat of the ore is 10,375 MJ / h, and 10,080 MJ / h can be recovered when using a heat medium of 60 ton / h. Additionally, when the moisture content of the ore residue is reduced from 30% to 20%, 2.5 ton / h of water vaporization is required, and 5,650 MJ / h of heat energy is needed. Since the recovered heat energy is approximately twice the required heat energy, it can be confirmed that about 5 ton / h of moisture can be removed. Although preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and it is possible to implement various modifications within the scope of the claims, the detailed description of the invention, and the attached drawings, and it is obvious that such modifications also fall within the scope of the present invention. Therefore, the actual scope of rights of the present invention shall be defined by the attached claims and their equivalents.

Claims

1. A step of obtaining calcined ore by calcining a lithium-containing ore; A step of contacting a heat medium with the above-mentioned calcined ore to secure thermal energy of the heat medium through heat exchange; A step of separating the heat medium from the calcined ore, from which the above thermal energy has been secured; and A method for treating lithium-containing ore comprising the step of utilizing the separated heat medium in a process requiring thermal energy.

2. In Paragraph 1, A step of obtaining roasted ore by roasting the calcined ore separated from the heat medium; and A method for treating lithium-containing ore, further comprising the step of leaching and purifying the above-mentioned roasted ore to obtain a residue.

3. In Paragraph 2, The step of utilizing the above-mentioned separated heat medium in other processes requiring thermal energy; A method for treating lithium-containing ore, comprising the step of contacting the separated heat medium with the residue to evaporate the moisture contained in the residue.

4. In Paragraph 3, The step of evaporating moisture contained in the above residue; A method for treating lithium-containing ore, wherein the above-described separated heat medium is brought into direct contact with the above-described residue to evaporate moisture through heat conduction.

5. In Paragraph 3, A method for treating lithium-containing ore, wherein the mixing ratio of the residue and the separated heat medium is 1:1.5 to 1:

3.

6. In Paragraph 4, A step of bringing the separated heat medium into direct contact with the residue to evaporate moisture through heat conduction; after A method for treating lithium-containing ore, further comprising the step of separating the separated heat medium and the residue from which moisture has evaporated.

7. In Paragraph 6, A method for treating lithium-containing ore, wherein the moisture content in the residue from which the above moisture has evaporated is 5 to 25%.

8. In Paragraph 6, A method for treating lithium-containing ore, wherein the evaporation rate of the above moisture is 1 to 3 ton / h.

9. In Paragraph 1, In the step of contacting a heat medium with the above-mentioned calcined light; The temperature of the above calcined ore is 800 to 1100℃, and A method for treating lithium-containing ore, wherein the temperature of the heat medium is 25 to 100℃.

10. In Paragraph 1, In the step of separating the heat medium that has secured the above thermal energy and the above calcined ore; A method for treating lithium-containing ore, wherein the temperature of the heat medium that secures the above thermal energy is 400 to 600℃.

11. In Paragraph 1, A method for treating lithium-containing ore, wherein the heat medium after use in the step of utilizing the separated heat medium in a process requiring thermal energy is reintroduced into the step of contacting the heat medium with the calcined ore.

12. In Paragraph 1, In the step of contacting a heat medium with the above-mentioned calcined light; The input speed of the above heat medium is 40 to 70 ton / h, and A method for treating lithium-containing ore, wherein the particle size of the heat medium is 5 to 15 mm.

13. In Paragraph 1, A method for treating lithium-containing ore, wherein the type of heat medium comprises at least one of iron beads, copper-iron beads, ceramic beads, carbon steel beads, stainless beads, chrome steel beads, tungsten beads, and brass beads.

14. In Paragraph 1, The sensible heat of the above calcined ore is 9,000 to 12,000 MJ / h, and A method for processing lithium-containing ore, wherein the supply rate of the above-mentioned calcined ore is 15 to 30 ton / h.

15. In Paragraph 1, A method for treating a lithium-containing ore, wherein the lithium-containing ore comprises one or more selected from the group consisting of spodumene, petalite, lepidolite, hectorite, eucryptite, jadarite, zinnwaldite, and amblygonite.

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