Method for efficiently extracting lithium and high-purity quartz from low-grade hydrothermal alteration type lithium ore

Abstract

This invention discloses a method for efficient lithium extraction and high-purity quartz extraction from low-grade hydrothermal alteration lithium ore, belonging to the field of lithium ore beneficiation, processing, and comprehensive utilization technology. The method includes: S1, ore crushing; S2, pre-treated material screening; S3, grinding of the over-screen product; S4, stirring, scrubbing, settling, and desliming; S5, weak magnetic separation; S6, strong magnetic separation; S7, reverse flotation separation; S8, hot-pressing acid leaching; S9, merging of slime; S10, low-temperature lithium extraction; S11, leaching residue detection; and S12, high-purity quartz sand detection. The raw ore is pre-screened to a coarse particle size of +40 mesh before entering the grinding mill, reducing grinding costs. The separated total mud, mica, and feldspar are then added to lithium extraction reagents. There is no need for pretreatment such as high-temperature roasting or adding salt roasting aids, nor is there a need for concentrated sulfuric acid. Lithium can be directly and efficiently extracted by low-temperature, low-pressure, low-concentration acid, and room-temperature water immersion and stirring. This method has low corrosiveness to equipment, is energy-saving and environmentally friendly, has strong adaptability to raw materials, is green and clean, and has a lithium leaching rate of up to 90%, significantly improving the comprehensive utilization level of lithium ore.

Description

Technical Field

[0001] This invention belongs to the field of lithium ore beneficiation, processing and comprehensive utilization. Specifically, it relates to a method for efficient lithium extraction and high-purity quartz extraction from low-grade hydrothermal alteration lithium ore. Background Technology

[0002] Lithium is the world's smallest known rare alkaline earth metal element in terms of atomic radius, lightest mass, and highest ionization potential. It is listed as a key metal by countries such as the United States, Japan, and Australia, and is widely used in glass ceramics, lubricating greases, non-ferrous metallurgy, clinical medicine, air treatment, high-energy batteries, nuclear fusion, and aerospace. It enjoys the reputation of being the "industrial MSG" and "the most promising metal in the 21st century".

[0003] Lithium in nature occurs in two forms: solid mineral resources and liquid deposits. Solid lithium mineral resources mainly include spodumene, lepidolite, and petalite, with hard rock solid ores accounting for about 29%, sedimentary lithium deposits about 7%, and liquid brine deposits about 64%. my country's dependence on imported lithium resources exceeds 80%. According to the current mainstream classification of global lithium resources, lithium deposits are mainly divided into three categories: hard rock, brine, and sedimentary. Hard rock lithium deposits are mainly divided into pegmatite and granite types, sedimentary lithium deposits are mainly volcanic sedimentary and carbonate weathering-sedimentary types, and brine deposits are mainly found in salt lakes and will not be discussed here. The following discusses the basic characteristics of each type of lithium deposit according to its type:

[0004] (1) Characteristics of pegmatite-type lithium deposits: The parent rock of the ore-forming deposit is pegmatite, and the lithium-bearing mineral is spodumene. The deposit is mainly formed by magmatic differentiation and evolution. Highly differentiated pegmatites are enriched incompatible elements such as lithium and beryllium, thus forming minerals. The parent rock has a high degree of differentiation and evolution. (2) Characteristics of granite-type lithium deposits: The parent rock of the ore-forming deposit is granite, and the lithium-bearing mineral is mainly lepidolite. The deposit is mainly formed by magmatic differentiation and evolution. Highly differentiated pegmatites are enriched in lithium, thus forming minerals. The parent rock has a high degree of differentiation and evolution. (3) Characteristics of volcanic sedimentary lithium deposits: The parent rock of the ore-forming deposit is mainly volcanic clastic rocks such as tuff. The lithium-bearing minerals are mainly clay minerals such as lithium montmorillonite and lithium saponite. The deposit is mainly formed by the interaction between volcanic materials and hot aqueous solutions or evaporated brine, which can form unconventional lithium-bearing minerals, thus forming lithium deposits. (4) Characteristics of carbonate rock weathering-sedimentary lithium deposits: The parent rocks of the minerals are mainly carbonate rocks such as limestone, and the minerals that contain lithium are mainly clay minerals such as lithium montmorillonite. The deposits are formed by the secondary enrichment of lithium-bearing minerals through weathering and sedimentation.

[0005] The low-grade hydrothermal alteration lithium deposits recently discovered in my country are significantly different from the lithium resources already reported worldwide. Firstly, the parent rock of the mineralization in the Jingde area of ​​Anhui Province is the Jingde pluton granodiorite, and the lithium-bearing minerals are mainly hydrothermal alteration minerals such as lithium chlorite. The deposit was formed mainly by the upwelling of deep lithium-rich hydrothermal fluids along fault channels, which mineralized and altered the feldspar and other minerals in the surrounding rock, producing lithium-rich minerals such as lithium chlorite, thus forming the corresponding lithium resources. The parent rock of the Jingde pluton is not highly evolved and belongs to low-evolution granodiorite.

[0006] Currently, there are two main types of raw materials for lithium extraction: one is from spodumene and lepidolite ores, and the other is from liquid resources such as salt lake brine and well brine. Lithium extraction processes from spodumene mainly include the sulfuric acid process, alkaline process, sulfate roasting process, and chlorination roasting process; lithium extraction methods from lepidolite mainly include the sulfuric acid process, limestone sintering process, sulfate roasting process, pressure cooking process, and chlorination roasting process. Both processes primarily involve first roasting and activating the minerals at high temperatures of 800–1200℃, and then leaching lithium with sulfuric acid to generate lithium salts. Lithium extraction methods from salt lake brine mainly include evaporation crystallization, precipitation, solvent extraction, ion exchange adsorption, calcination leaching, salting out, and the "Xu's method," among others.

[0007] Patent CN 115161496 A discloses a method for extracting lithium from lithium clay. The method involves calcining lithium clay powder at 500–800°C for 1–5 hours, grinding the calcined material, mixing it with a leaching agent and water, and then leaching it at 150–300°C and 1.4–2.5 MPa. This method grinds all the lithium clay into powder for high-temperature calcination. The resulting agglomerates need to be ground again before reacting with the leaching agent, resulting in high grinding costs and high energy consumption.

[0008] Patent CN 109022722A discloses "A method for leaching lepidolite with sulfuric acid". It involves mixing 90-98% concentrated sulfuric acid into finely ground lepidolite concentrate and aging it at 100-250℃ for 2-20 hours. The patent requires the use of 90-98% concentrated sulfuric acid at temperatures above 100℃. Heating concentrated sulfuric acid will generate acid gas that corrodes the equipment. It also consumes a large amount of alkali. The excess sulfuric acid is converted into sulfate after alkali treatment, resulting in high lithium extraction costs.

[0009] Patent CN 115198109 A discloses a method for extracting lithium from lithium-containing clay using a mixed acid. The method involves thoroughly mixing lithium-containing clay ore powder with a mixture of concentrated sulfuric acid and concentrated phosphoric acid at a solid-liquid ratio of 1:3 to 1:8, and leaching at 50 to 150°C for 2 to 6 hours. The lithium leaching rates are 52.12%, 55.96%, 60.58%, 77.83%, and 91.02%, respectively. In contrast, directly grinding the lithium ore into powder and mixing it with concentrated sulfuric acid and concentrated phosphoric acid not only results in strong acid corrosion of equipment and requires alkali treatment, increasing lithium extraction costs, but also generates a large amount of tailings.

[0010] CN 109593974 B discloses "A method for extracting lithium from lithium ore". The method involves mixing lithium ore with calcium oxide and pulverized coal, reacting the mixture at a high temperature of 1200-1500℃ for 0.5-3 hours, quenching the reaction product in water, and then rapidly cooling it to obtain water-quenched slag. The water-quenched slag is then finely ground and leached with sulfuric acid solution to obtain a lithium-containing solution. Lithium salts are then obtained from the solution through chemical precipitation. This patent requires the addition of additives and calcination at a high temperature above 1000℃. The water quenching followed by fine grinding results in high grinding costs and high calcination temperatures, leading to high lithium extraction costs.

[0011] The above-mentioned lithium extraction processes are relatively mature, all involving grinding lithium ore into powder, followed by pretreatment with concentrated acid mixed with the finely ground powder, high-temperature calcination, or high-temperature calcination with the addition of roasting aids. None of these processes recover non-metallic minerals such as quartz, mica, and feldspar from the lithium ore. The grinding costs are high, the amount of tailings generated is large, resulting in resource waste, high equipment investment, and high energy consumption. For low-grade hydrothermal alteration lithium ores, the high-temperature calcination method is too costly, potentially leading to low development and utilization value. Therefore, the above-mentioned lithium extraction methods using spodumene and lepidolite are not suitable for low-grade hydrothermal alteration lithium ores.

[0012] In view of this, the present invention is proposed. Summary of the Invention

[0013] The technical problem this invention aims to solve is to overcome the shortcomings of existing technologies and provide a method for efficient lithium extraction and high-purity quartz extraction from low-grade hydrothermal alteration lithium ore. The method involves pre-screening and feeding a portion of the ore with 40-mesh coarse particles into the grinding process. After pre-tailing, lithium-containing minerals are preferentially enriched. Simultaneously, a novel flotation reagent is used to efficiently separate feldspar and quartz from the lithium ore. The separated products are then added to dilute acid as a lithium extraction reagent, and a low-temperature roasting-water leaching method is employed. The overall lithium leaching rate reaches a maximum of 90.07%. This method is green, energy-saving, and environmentally friendly. The mica and feldspar leaching residues can be used as siliceous raw materials for cement batching, aerated concrete blocks, etc., reducing tailings emissions. The resulting quartz concentrate has an SiO2 content of 99.94% and an Fe content of 4.38 mg / kg, meeting the standards for low-end high-purity quartz products. Overall, this method improves the comprehensive utilization level of low-grade hydrothermal alteration lithium ore.

[0014] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by the present invention is as follows:

[0015] A method for efficiently extracting lithium and high-purity quartz from low-grade hydrothermal alteration lithium ore includes the following steps:

[0016] (1) Ore crushing: Low-grade hydrothermal alteration lithium ore is pre-treated by jaw crusher-roll crusher to obtain pre-treated material with a particle size of -1mm.

[0017] (2) Screening of pretreated material: The -1mm pretreated material obtained in step (1) is screened by a sieve;

[0018] (3) Grinding the oversize product: Grind the +40 mesh oversize product obtained in step (2) to screen out -200 mesh fine mud product;

[0019] (4) Stirring and scrubbing - settling and desliming: The grinding product obtained in step (3) is classified to obtain -40+200 mesh coarse sand, which is combined with the -40+200 mesh coarse sand obtained in step (2) to obtain qualified particle size, and then stirred and scrubbing - settling and desliming.

[0020] (5) Weak magnetic separation: The deslimed coarse sand product obtained in step (4) is subjected to wet weak magnetic separation to remove iron;

[0021] (6) Strong magnetic separation: The product obtained in step (5) after removing the magnetic iron is subjected to strong magnetic separation under a high gradient magnetic field of 1.2 to 1.8T to obtain mica concentrate and non-magnetic materials;

[0022] (7) Reverse flotation separation: The non-magnetic material obtained in step (6) is separated by reverse flotation using a novel collector under pH conditions of 2-3 to obtain quartz concentrate and feldspar concentrate;

[0023] (8) Hot pressing acid leaching: The flotation quartz concentrate obtained in step (7) is subjected to hot pressing acid leaching, washing and drying to obtain high-purity quartz concentrate.

[0024] (9) Combine the -200 mesh products obtained in steps (2), (3), and (4) above to obtain the total mud product;

[0025] (10) Low-temperature lithium extraction: The mica concentrate obtained in step (6), the feldspar concentrate obtained in step (7), and the total mud obtained in step (9) are respectively added to the lithium extraction reagent for low-temperature lithium extraction;

[0026] (11) Leaching residue detection: The mica leaching residue, feldspar leaching residue and total mud leaching residue obtained in step (10) were detected by ICP-AES to calculate the cumulative leaching rate of lithium to the raw ore. At the same time, the mica leaching residue and feldspar leaching residue were analyzed for SiO2, Al2O3, Fe2O3, K2O and Na2O to examine their uses in building materials and other aspects.

[0027] (12) High-purity quartz sand test: The high-purity quartz sand obtained in step (8) was subjected to 13 trace element ICP-MS tests to check whether it could meet the requirements of high-purity quartz index.

[0028] Furthermore, in step (1), the ore crushing equipment is a laboratory jaw crusher-roll crusher-double-layer vibrating screen, which meets the requirement of -1mm particle size for the pre-treated material sample after crushing.

[0029] Furthermore, in step (2), the -1mm pretreated material is used as the raw ore for screening using a sieve. The screening equipment is a standard sieve for laboratory use, with mesh sizes of 25, 40, 60, 80, 120, 140, and 200, which meets the particle size classification requirements.

[0030] Furthermore, in step (3), the coarse particles on the +40 mesh screen of the raw ore are ground by a three-roller four-cylinder rod mill for 3 to 15 minutes. After grinding, the -200 mesh fine mud product is screened out, and the remaining products are qualified particle size of -40 +200 mesh.

[0031] Further, in step (4), the stirring and scrubbing-sedimentation desliming process involves mixing and scrubbing the raw ore after screening to obtain 40+200 mesh coarse sand and after regrinding to obtain 40+200 mesh coarse sand in an XFD12 scrubbing machine. The scrubbing slurry concentration is 50%, the scrubbing time is 30 minutes, and the fine mud is removed by siphon sedimentation until the slurry is clear.

[0032] Furthermore, in step (5), the weak magnetic separation is a single-stage wet weak magnetic separation with a magnetic field strength of 1500-2000 Oe;

[0033] Furthermore, in step (6), the strong magnetic separation is a high gradient magnetic separation with a magnetic field strength of 1.2 to 1.8 T.

[0034] Further, in step (7), the reverse flotation separation is aerated flotation, the flotation machine is an XFD12 multi-cell flotation machine, and the process conditions are as follows: the pulp pH is adjusted to 2-3, the acid is one or a mixture of sulfuric acid, oxalic acid, nitric acid, and hydrochloric acid, the reverse flotation pulp concentration is 15-30%, the dosage of the novel separation collector is 400-600 g / t, the dosage of the frother is 50-100 g / t, the stirring rate is 800-1200 r / min, and the flotation time is 2-5 min. The novel collector is a mixture of compound amine, fatty acid, and silicate inhibitor, and the frother is a mixture of hydrocarbon oil and pine oil.

[0035] Further, in step (8), the hot-press acid leaching process is at least one of ultrasonic acid leaching, stirring acid leaching, and heating acid leaching. The acid used is a mixed acid, which is a combination of two or more of hydrofluoric acid, nitric acid, hydrochloric acid, sulfuric acid, and oxalic acid. The leaching time is 4 to 24 hours.

[0036] Further, in step (9), the mud is combined: the -200 mesh fine mud screened from the original ore, the -200 mesh fine mud produced after re-grinding the +40 mesh, and the fine mud produced by stirring and scrubbing the qualified particle size of -40+200 mesh are combined into total mud.

[0037] Further, in step (10), the low-temperature lithium extraction is as follows: the processing temperature is 100-200℃, the lithium extraction reagent AC is a diluted acid with a concentration of 30%-75%, the heat preservation time is 1-5h, the water immersion stirring time is 0.5-1h, the water immersion stirring temperature is 20-90℃, and the immersion residue is filtered and rinsed until neutral.

[0038] Furthermore, in step (11), the leaching residue detection involves weighing the leaching residue sample and performing various index detections using inductively coupled plasma atomic emission spectrometry (ICP-AES) and colorimetry, in accordance with the regional geochemical sample analysis method.

[0039] Furthermore, in step (12), the high-purity quartz sand is detected by inductively coupled plasma mass spectrometry (ICP-MS) in an ultra-clean laboratory to detect 13 trace elements.

[0040] This invention relates to hydrothermal alteration lithium ore with low Li2O content. Lithium ore morphology analysis results show that: residual state accounts for 99.23%, ion-adsorbed state accounts for 0.33%, strongly organically bound state accounts for 0.22%, iron-manganese oxide state accounts for 0.18%, and carbonate-bound state accounts for 0.04%. Through cation exchange capacity testing, only 0.65% of Li was exchanged into the solution, indicating that lithium mainly exists in lattice form within chlorite. Chlorite is prone to mud formation during crushing and grinding, and is classified as gangue mineral in mineral sorting. Therefore, conventional beneficiation methods such as gravity separation, flotation, and magnetic separation cannot be used to directly extract lithium. For this type of lithium ore hosted in chlorite, the conventional method is to directly grind the entire ore into powder and add concentrated sulfuric acid or a mixture of several concentrated acids to extract lithium, resulting in excessively high grinding costs. This invention, based on cost-saving and environmental protection principles, uses a pre-screening process with a coarse particle size of +40 mesh before entering the grinding system. Only about 50% of the ore enters the grinding system, significantly reducing grinding costs.

[0041] This invention obtains the mineral composition of lithium ore based on XRD. After the beneficiation process, lithium-enriched mud products, mica products, and feldspar products are respectively added with lithium extraction reagents. There is no need for pretreatment such as high-temperature roasting or adding salt roasting aids, nor is it necessary to use concentrated sulfuric acid, high temperature and high pressure. The invention uses low temperature and low pressure, and the lithium extraction reagent is concentrated sulfuric acid, concentrated hydrochloric acid, or a mixture of the two diluted in a certain proportion. Lithium can be directly and efficiently extracted by immersion and stirring in water at room temperature, saving lithium extraction costs. It has low corrosiveness to equipment, is energy-saving and environmentally friendly, has strong adaptability to raw materials, is green and clean, and has a lithium leaching rate of up to 90%.

[0042] Low-temperature lithium extraction involves acidifying and roasting hydrothermal altered lithium ore with a certain concentration of acid at a low temperature (100–200°C) to obtain acidified clinker, which is then leached with water under stirring. The principle is that acid treatment at a certain temperature loosens the structure of hydrothermal altered lithium-bearing chlorite, allowing H... + The ions are small in size and can easily enter the lithium chlorite structure to occupy Li. + Al 3+ Fe 3 + Mg 2+ Fe 2+ The position of the metal ions, thus Li + Al 3+ Fe 3+ Mg 2+ Fe 2+ After the metal ions dissolve, a lithium sulfate solution is finally formed.

[0043] The novel reagent used in this invention can efficiently separate and recover feldspar and quartz from low-grade lithium ore, yielding quartz concentrate with a yield of 10-15%, SiO2 content of 99.94%, and Fe content of 4.82 μg / g, which can be used as high-purity quartz concentrate. Currently, low-iron high-purity quartz sand is valued at 2,000-4,000 yuan / ton, significantly increasing the economic benefits of mines.

[0044] The mica and feldspar leaching residues obtained after lithium extraction in this invention have a yield of 45%–55%. After filtration and washing to neutrality, both can be used as siliceous raw materials for cement batching, aerated concrete block production, and other applications, reducing tailings emissions and significantly improving the comprehensive utilization level of lithium ore. This results in good social, economic, and environmental benefits. Furthermore, this invention has strong applicability and a wide range of applications, suitable for industrial production and possessing a broader market potential.

[0045] This invention pertains to the comprehensive utilization of low-grade ore resources. The coarse particles enter the grinding system, which can greatly reduce grinding costs. It prioritizes the enrichment of lithium-containing minerals to improve grade, and uses low-temperature dilute acid to efficiently convert lithium ions. It also comprehensively recovers quartz from lithium ore to meet the requirements of high-purity quartz, while separating mica and feldspar. The leaching residue after lithium extraction can be used for building materials, increasing economic benefits and reducing tailings stockpiling. This aligns with the concept of green mining and the trend of the times.

[0046] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art.

[0047] This invention involves pre-screening the raw ore into coarse particles (+40 mesh) before grinding, reducing grinding costs. The separated mud, mica, and feldspar are then added to lithium extraction reagents, eliminating the need for pretreatment such as high-temperature roasting or the addition of salt roasting aids. It also eliminates the need for concentrated sulfuric acid, using low-temperature, low-pressure, low-concentration acid, and room-temperature water leaching with stirring for direct and efficient lithium extraction. This invention exhibits low corrosivity to equipment, energy efficiency, environmental friendliness, strong adaptability to raw materials, and a green and clean process, achieving a lithium leaching rate of up to 90%.

[0048] The novel reagent used in this invention can efficiently separate and recover feldspar and quartz from hydrothermal alteration lithium ore, yielding quartz concentrate with a SiO2 content of 99.94% and Fe content of 4.38 μg / g, which can be used as high-purity quartz concentrate. The mica leaching residue and feldspar leaching residue can be used as siliceous raw materials for cement batching, aerated bricks, and other applications, reducing tailings emissions and significantly improving the comprehensive utilization level of lithium ore, thus having good social, economic, and environmental benefits.

[0049] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0050] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation of the invention. Obviously, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without creative effort. In the drawings:

[0051] Figure 1 This is a schematic diagram of the method flow of the present invention.

[0052] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0054] The raw ore used in the following examples and comparative examples is a low-grade hydrothermal alteration lithium deposit. This lithium deposit is a new type of lithium mineralization discovered in Anhui Province. The mineralization of the lithium ore is hydrothermal, and the lithium-bearing mineral is the hydrothermal alteration mineral chlorite, rather than the traditional lithium deposits of lepidolite and spodumene. Lepidolite and spodumene are the result of magmatic evolution. Chemical analysis results of the raw ore: SiO2 64.47%, Al2O3 19.60%, Fe2O3 3.55%, K2O 3.48%, CaO 1.62%, Na2O 0.85%, MgO 0.98%. XRD analysis results of the raw ore: Quartz 30.47%, orthoclase 23.07%, albite 9.04%, muscovite 17.66%, clinochlore 19.77%.

[0055] Example 1: Low-Temperature Lithium Extraction

[0056] like Figure 1 As shown in this embodiment, a method for efficient lithium extraction and high-purity quartz extraction from low-grade hydrothermal alteration lithium ore includes the following steps:

[0057] (1) Take 500 grams of raw ore that has been crushed and pre-treated to -1 mm and contains 0.22% Li2O. Use 40 mesh, 60 mesh, 80 mesh, 120 mesh, 140 mesh and 200 mesh sieves for sieving analysis to obtain three particle size products: +40 mesh, -40+200 mesh and -200 mesh.

[0058] (2) The +40 mesh particle size obtained in step (1) is subjected to a large cylinder rod mill for 4 minutes, the grinding concentration is 50%, the -200 mesh fine mud is removed by wet screening, the sieve is dried and checked, and then the sieve analysis is performed by a set of 40 mesh, 60 mesh, 80 mesh, 120 mesh, 140 mesh and 200 mesh sieves to obtain three particle size products: +40 mesh, -40+200 mesh and -200 mesh.

[0059] (3) Combine the qualified particle size of -40+200 mesh obtained in steps (1) and (2), pour it into the XFD12 scrubbing machine and stir and scrub for 30 minutes. The slurry concentration is 50%. Siphon sedimentation removes the sludge until the water is clear.

[0060] (4) The coarse sand obtained after desliming in step (3) is fed into a wet weak magnetic separator with a magnetic field strength of 1700 Oe to remove magnetic iron.

[0061] (5) The non-magnetic material obtained in step (4) is fed into a wet high-intensity magnetic separator with a magnetic field strength of 1.4T to obtain magnetic mica concentrate and non-magnetic material.

[0062] (6) Weigh a certain amount of the non-magnetic material obtained in step (5) and add it to the 0.5L flotation cell of the XFD12 flotation machine. The flotation pulp concentration is 20%, and the pulp pH is adjusted to 2-3 with sulfuric acid. Add 400g / t of the new reverse flotation feldspar reagent and 50g / t of the frother. The flotation frothing time is 2 minutes, and the stirring speed is 1500r / min. The frothing product after roughing and scavenging is feldspar concentrate, and the product in the cell is quartz concentrate. The new collector is a mixture of compound amine, fatty acid, and silicate inhibitor, and the frother is a mixture of hydrocarbon oil and pine oil.

[0063] (7) Combine the -200 mesh fine mud obtained in steps (1)(2)(3), weigh 3 grams of each of the mica concentrate in step (5) and the feldspar concentrate in step (6), add 45% dilute acid lithium extraction reagent, with a liquid-to-solid ratio of 1.5:1, stir evenly, and then put it in a 150℃ oven for 4 hours. After the end, add water with a liquid-to-solid ratio of 3:1 for immersion, with a water immersion stirring temperature of 28℃ and a stirring time of 1 hour. After immersion residue is filtered, rinse until neutral.

[0064] (8) The quartz concentrate obtained in step (6) is subjected to hot-press acid leaching. The hot-press acid leaching process is at least one of ultrasonic acid leaching, stirring acid leaching, and heating acid leaching. A mixed acid is added at a liquid-to-solid ratio of 1:2. The mixed acid is at least one of hydrochloric acid, nitric acid, and hydrofluoric acid or a mixture thereof. The mixture is hot-pressed and acid-leached at 70°C for 24 hours. It is then washed with ultrapure water until neutral and 13 trace elements are tested.

[0065] (9) After the stirring leaching in step (7), the mica leaching residue, feldspar leaching residue, and total mud leaching residue were subjected to liquid-solid separation to obtain leachate and leaching residue. The leaching residue was dried and the lithium content was analyzed by ICP-AES to calculate the lithium leaching rate. The results of low-temperature lithium extraction in Example 1 are shown in Table 1, and the analysis results of high-purity quartz concentrate are shown in Table 2.

[0066] Table 1 Results of low-temperature lithium extraction in Example 1

[0067]

[0068] Table 2. Analysis results of high-purity quartz concentrate

[0069] Content (μg / g) 99.94 4.38 0.36 0.19 0.05 0.12 0.70 element Ca Al Na Li K Ti Content (μg / g) 51.89 390.98 15.65 40.21 12.07 64.76

[0070] Example 2: Low-Temperature Lithium Extraction

[0071] like Figure 1 As shown, the method in this embodiment includes the following steps:

[0072] (1) Take 500 grams of raw ore that has been crushed and pre-treated to -1 mm and contains 0.20% Li2O. Use 40 mesh, 60 mesh, 80 mesh, 120 mesh, 140 mesh and 200 mesh sieves for sieve analysis to obtain three particle size products: +40 mesh, -40+200 mesh and -200 mesh.

[0073] (2) The +40 mesh particle size obtained in step (1) is subjected to a medium-cylinder rod mill for 15 minutes, with a grinding concentration of 50%. The -200 mesh fine mud is removed by wet screening, dried and screened. The sieve is then used to perform sieve analysis with 40 mesh, 60 mesh, 80 mesh, 120 mesh, 140 mesh and 200 mesh sieves to obtain three particle size products: +40 mesh, -40+200 mesh and -200 mesh.

[0074] (3) Combine the qualified particle size of -40+200 mesh obtained in steps (1) and (2), pour it into the XFD12 scrubbing machine and stir and scrub for 30 minutes. The slurry concentration is 50%. Siphon sedimentation removes the sludge until the water is clear.

[0075] (4) Weigh a certain amount of the coarse sand obtained in step (3) and add it to the 0.5L flotation cell of the XFD12 flotation machine. The flotation pulp concentration is 25%. Adjust the pulp pH to 2-3 with sulfuric acid. Add 300g / t of new reverse flotation mica reagent and 40g / t of frother. The frothing product after roughing and scavenging is mica concentrate. Then add 200g / t of direct flotation reagent. Direct flotation yields quartz concentrate, and the product in the cell is feldspar concentrate. The direct flotation reagent is a polymer of alkaline earth metal cations and alkyl sulfonates.

[0076] (5) Combine the -200 mesh fine mud obtained in steps (1)(2)(3), weigh 3 grams of each of the mica concentrate and feldspar concentrate from step (4), add 35% dilute acid lithium extraction reagent, liquid-solid ratio 2:1, stir evenly and then put into a 130℃ oven for 5 hours. After the end, add water with a liquid-solid ratio of 4:1 for immersion, water immersion stirring temperature 25℃, stirring time 0.5 hours, filter the immersion residue and rinse until neutral.

[0077] (6) The quartz concentrate obtained in step (4) is subjected to hot-press acid leaching. The hot-press acid leaching process is at least one of ultrasonic acid leaching, stirring acid leaching, and heating acid leaching. A mixed acid is added at a liquid-to-solid ratio of 2:1. The mixed acid is at least one of hydrochloric acid, nitric acid, and hydrofluoric acid or a mixture thereof. The mixture is hot-pressed and acid-leached at 70°C for 23 hours. The mixture is washed with ultrapure water until neutral and 13 trace elements are tested.

[0078] (7) After the stirring leaching in step (5), the mica leaching residue, feldspar leaching residue, and total mud leaching residue were subjected to liquid-solid separation to obtain leachate and leaching residue. The leaching residue was dried and the lithium content was analyzed by ICP-AES to calculate the lithium leaching rate. The results of low-temperature lithium extraction in Example 2 are shown in Table 3, and the analysis results of high-purity quartz concentrate are shown in Table 4.

[0079] Table 3 Results of low-temperature lithium extraction in Example 2

[0080]

[0081] Table 4. Analysis results of high-purity quartz concentrate

[0082]

[0083]

[0084] Analysis of the high-purity quartz concentrate showed that the Fe content was 29.94 mg / kg, the Al content was 315.5 mg / kg, the SiO2 content was increased to 99.95%, and the total impurities were 490.03 mg / kg ≤ 1000 mg / kg. The acid-leached concentrate obtained by the invention reached the level of a low-end high-purity quartz product.

[0085] Example 3: Low-Temperature Lithium Extraction

[0086] The difference between this embodiment and Embodiment 1 is as follows:

[0087] The product with a particle size greater than +40 mesh obtained from the raw ore containing 0.21% Li2O was regrinded in a large-cylinder rod mill for 5 minutes. 3 grams of the prepared total mud, feldspar, and mica were weighed out respectively, and 55% concentration of dilute acid lithium extraction reagent was added. After stirring evenly at a liquid-to-solid ratio of 1.3:1, the mixture was placed in a 140℃ incubator for 4 hours. After the incubation, water with a liquid-to-solid ratio of 3:1 was added for immersion. The water immersion stirring temperature was 30℃, and the mixture was stirred for 45 minutes. The results of low-temperature lithium extraction are shown in Table 5.

[0088] Table 5 Example 3 Low-Temperature Lithium Extraction

[0089]

[0090] Example 4: Low-Temperature Lithium Extraction

[0091] The difference between this embodiment and Embodiment 1 is as follows:

[0092] Hydrothermal alteration lithium ore with a Li2O content of 0.12% was directly ground to -200 mesh (90%). 3 grams of sample were weighed and added to a 75% concentration of dilute acid lithium extraction reagent. The mixture was stirred evenly at a liquid-to-solid ratio of 1.3:1 and placed in a 135℃ oven for 6 hours. After the oven was heated, water with a liquid-to-solid ratio of 4:1 was added for leaching. The water leaching stirring temperature was 50℃ and the stirring time was 1 hour. The low-temperature lithium extraction index was a Li2O leaching rate of 93.51%.

[0093] Example 5: Low-Temperature Lithium Extraction

[0094] The difference between this embodiment and Embodiment 1 is as follows:

[0095] Hydrothermal alteration lithium ore with a Li2O content of 0.17% was directly ground to -200 mesh (90%). 3 grams of sample were weighed and added to a 75% concentration of dilute acid lithium extraction reagent. The mixture was stirred evenly at a liquid-to-solid ratio of 1.3:1 and placed in a 135℃ oven for 6 hours. After the oven was heated, water with a liquid-to-solid ratio of 4:1 was added for leaching. The water leaching stirring temperature was 50℃ and the stirring time was 1 hour. The low-temperature lithium extraction index was a Li2O leaching rate of 94.57%.

[0096] Example 6: Low-Temperature Lithium Extraction

[0097] The difference between this embodiment and Embodiment 1 is as follows:

[0098] Hydrothermal alteration lithium ore with a Li2O content of 0.2% was directly ground to -200 mesh (90%). 3 grams of sample were weighed and added to a 75% concentration of dilute acid lithium extraction reagent. The mixture was stirred evenly at a liquid-to-solid ratio of 1.3:1 and placed in a 135℃ oven for 6 hours. After the oven was heated, water with a liquid-to-solid ratio of 4:1 was added for leaching. The water leaching stirring temperature was 50℃ and the stirring time was 1 hour. The low-temperature lithium extraction index was a Li2O leaching rate of 96.10%.

[0099] Example 7: Low-Temperature Lithium Extraction

[0100] The difference between this embodiment and Embodiment 1 is as follows:

[0101] Hydrothermal alteration lithium ore with a Li2O content of 0.25% was directly ground to -200 mesh (90%). 3 grams of sample were weighed and added to a 75% concentration of dilute acid lithium extraction reagent. The mixture was stirred evenly at a liquid-to-solid ratio of 1.3:1 and placed in a 135℃ oven for 6 hours. After the oven was heated, water with a liquid-to-solid ratio of 4:1 was added for leaching. The stirring temperature during leaching was 20℃ (room temperature) and the stirring time was 1 hour. The low-temperature lithium extraction index was a Li2O leaching rate of 94.59%.

[0102] Example 8: Low-Temperature Lithium Extraction

[0103] The difference between this embodiment and Embodiment 1 is as follows:

[0104] Hydrothermal alteration lithium ore with a Li₂O content of 0.31% was directly ground to -200 mesh (90%). 3 grams of the sample were weighed and added to a 75% concentration of dilute acid lithium extraction reagent. The mixture was stirred evenly at a liquid-to-solid ratio of 1.3:1 and placed in a 135℃ oven for 6 hours. After the oven was heated, water with a liquid-to-solid ratio of 4:1 was added for leaching. The water leaching temperature was increased to 50℃ and the stirring time was 1 hour. The low-temperature lithium extraction index was a Li₂O leaching rate of 96.35%. Under the same conditions, water leaching was carried out at room temperature with stirring at 20℃, and the Li₂O leaching rate was 95.14%.

[0105] Example 9: Low-Temperature Lithium Extraction

[0106] The difference between this embodiment and Embodiment 1 is as follows:

[0107] Hydrothermal alteration lithium ore with a Li2O content of 0.30% was directly ground to -200 mesh (90%). 3 grams of sample were weighed and added to a 35% concentration of dilute acid lithium extraction reagent. The mixture was stirred evenly at a liquid-to-solid ratio of 1.3:1 and placed in a 135℃ oven for 6 hours. After the oven was heated, water with a liquid-to-solid ratio of 4:1 was added for leaching. The water leaching stirring temperature was 24℃ and the stirring time was 1 hour. The Li2O leaching rate was 91.76%.

[0108] Example 10: Low-Temperature Lithium Extraction

[0109] The difference between this embodiment and Embodiment 1 is as follows:

[0110] Hydrothermal alteration lithium ore with a Li2O content of 0.30% was directly ground to -200 mesh (90%). 3 grams of sample were weighed and added to a 45% concentration of dilute acid lithium extraction reagent. The mixture was stirred evenly at a liquid-to-solid ratio of 1.3:1 and placed in an oven at 135℃ for 4 hours. After the process, water with a liquid-to-solid ratio of 3:1 was added for leaching. The water leaching stirring temperature was 24℃ and the stirring time was 1 hour. The Li2O leaching rate was 95.92%.

[0111] Comparative Example 1: High-Temperature Lithium Extraction

[0112] High-temperature lithium extraction conditions: The total mud, feldspar, and mica products were weighed to the same weight as those used in the low-temperature treatment. They were calcined in a muffle furnace at 700°C for 1 hour. A 45% concentration dilute acid, the same concentration and volume as in Example 1, was added. The mixture was stirred and leached in a magnetically stirred water bath at 90°C for 1 hour. The mixture was filtered and washed multiple times until neutral. The filter residue was dried, and the lithium content was measured using ICP-AES. The lithium extraction yield was calculated. The high-temperature lithium extraction yield is shown in Table 6.

[0113] Table 6 Results of high-temperature lithium extraction in Comparative Example 1

[0114]

[0115] Comparing Example 1 and Comparative Example 1, the low-temperature lithium extraction method yielded a cumulative leaching rate of 88.78% from the original ore, while the high-temperature method yielded 79.73%. The low-temperature method showed a 9.05% higher cumulative leaching rate than the high-temperature method. The green low-temperature lithium extraction technology of Example 1 demonstrates a significant advantage over the high-temperature lithium extraction method of Comparative Example 1, saving costs while maximizing the extraction of lithium as Li. + The form is transferred into the solution.

[0116] Comparative Example 2: High-Temperature Lithium Extraction

[0117] High-temperature lithium extraction conditions: The total mud, feldspar, and mica products were weighed to the same weight as those used in the low-temperature treatment. They were calcined in a muffle furnace at 700°C for 1 hour. A 35% concentration dilute acid, the same concentration and volume as in Example 2, was added. The mixture was stirred and leached in a magnetically stirred water bath at 90°C for 1 hour. The mixture was filtered and washed multiple times until neutral. The filter residue was dried, and the lithium content was measured using ICP-AES. The lithium extraction yield was calculated. The high-temperature lithium extraction yield is shown in Table 7.

[0118] Table 7 Comparative Example 2 High-Temperature Lithium Extraction Rate

[0119]

[0120] Example 2 and Comparative Example 2 illustrate that, by comparing low-temperature and high-temperature lithium extraction methods, the cumulative leaching rate of the raw ore is 90.07% for low-temperature lithium extraction and 67.17% for high-temperature lithium extraction, with the low-temperature method achieving a cumulative leaching rate 22.90% higher than the high-temperature method. The green low-temperature lithium extraction technology in Example 2 has significant advantages over the high-temperature lithium extraction technology in Comparative Example 2. This invention not only saves costs and achieves a high leaching rate, but also ensures that the low-temperature lithium extraction process is not affected by the beneficiation process or mineral particle size, resulting in a relatively stable lithium leaching rate.

[0121] Comparative Example 3: High-Temperature Lithium Extraction

[0122] High-temperature lithium extraction conditions: The total mud, feldspar, and mica products were weighed to the same weight as those used in the low-temperature treatment. They were calcined in a muffle furnace at 700°C for 1 hour. A 55% concentration dilute acid, the same concentration and volume as in Example 3, was added. The mixture was stirred and leached in a magnetically stirred water bath at 90°C for 1 hour. The mixture was filtered and washed multiple times until neutral. The filter residue was dried, and the lithium content was measured using ICP-AES. The lithium extraction yield was calculated. The high-temperature lithium extraction yield is shown in Table 8.

[0123] Table 8. High-Temperature Lithium Extraction Rate of Comparative Example 3

[0124]

[0125] Example 3 and Comparative Example 3 show that the cumulative leaching rate of lithium from the raw ore is 89.75% for low-temperature lithium extraction and 80.37% for high-temperature lithium extraction. The cumulative leaching rate of lithium from the raw ore is 9.38% higher for low-temperature lithium extraction than that for high-temperature lithium extraction, indicating that the method has a relatively stable lithium leaching rate.

[0126] Because the feldspar and mica leaching residues were repeatedly leached to neutral, the resulting product has a relatively coarse particle size of -40 to +200 mesh. Chemical analysis was conducted to investigate its applications in building materials. The analytical results are shown in Table 9.

[0127] Table 9. Analysis results of feldspar and mica leaching residues

[0128]

[0129] Both feldspar leaching residue and mica leaching residue can be used as siliceous raw materials for cement batching, aerated bricks, and other applications, generating good economic benefits. The yield of both parts is 50-55%, and the total mud yield is 30-40%, which can be used for brick and tile clay. The quartz concentrate yield is 10-15%. The ore products do not need to be discharged into the tailings pond. The invention truly achieves the comprehensive utilization of mineral resources and realizes tailings-free mine production.

[0130] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for efficiently extracting lithium and high-purity quartz from low-grade hydrothermal alteration lithium ore, characterized in that, Includes the following steps: (1) Ore crushing: Low-grade hydrothermal alteration lithium ore is crushed and pretreated to obtain pretreated material with a particle size of -1mm; (2) Screening of pretreated material: The -1mm pretreated material obtained in step (1) is screened by a sieve to obtain three particle size products: +40 mesh, -40 mesh to +200 mesh, and -200 mesh. (3) Grinding the oversize product: Grind the +40 mesh oversize product obtained in step (2), and after wet screening, dry the oversize product and dry screen it to screen out three particle size products: +40 mesh, -40 mesh ~ +200 mesh, and -200 mesh. (4) Stirring and scrubbing-sedimentation desliming: The grinding product obtained in step (3) is classified to obtain coarse sand of -40 mesh to +200 mesh, which is combined with the coarse sand of -40 mesh to +200 mesh obtained in step (2) to obtain qualified particle size. Stirring and scrubbing-sedimentation desliming is performed to obtain the deslimed coarse sand product and the removed -200 mesh fine mud. (5) Weak magnetic separation: The deslimed coarse sand product obtained in step (4) is subjected to wet weak magnetic separation to remove iron; (6) Strong magnetic separation: The product obtained in step (5) after removing the magnetic iron is subjected to strong magnetic separation under a high gradient magnetic field to obtain mica concentrate and non-magnetic materials; (7) Reverse flotation separation: The non-magnetic material obtained in step (6) is separated by reverse flotation with a collector under pH conditions of 2-3 to obtain feldspar concentrate and quartz concentrate; (8) Hot pressing acid leaching: The flotation quartz concentrate obtained in step (7) is subjected to hot pressing acid leaching, washing and drying to obtain high-purity quartz concentrate; (9) Merging mud: Merge the -200 mesh products obtained in steps (2), (3), and (4) above to obtain the total mud product; (10) Low-temperature lithium extraction: The mica concentrate obtained in step (6), the feldspar concentrate obtained in step (7), and the total mud obtained in step (9) are respectively added to the lithium extraction reagent for low-temperature lithium extraction; (11) Leaching residue detection: The lithium content of the mica leaching residue, feldspar leaching residue and total mud leaching residue obtained in step (10) was detected by ICP-AES. At the same time, the mica leaching residue and feldspar leaching residue were chemically analyzed. (12) High-purity quartz sand testing: The high-purity quartz sand obtained in step (8) was tested for 13 trace elements by ICP-MS in a cleanroom laboratory to examine the requirements of high-purity quartz index.

2. The method for efficient lithium extraction and high-purity quartz extraction from low-grade hydrothermal alteration lithium ore according to claim 1, characterized in that, In step (1), the crushing equipment is a laboratory jaw crusher-roll crusher-double-layer vibrating screen; in step (2), the screening equipment is a laboratory standard sieve with mesh sizes of 25, 40, 60, 80, 120, 140, and 200.

3. The method for efficient lithium extraction and high-purity quartz extraction from low-grade hydrothermal alteration lithium ore according to claim 1, characterized in that, In step (3), a three-roller four-cylinder rod mill is used for grinding. The grinding time is 3 to 15 minutes. After grinding, the -200 mesh fine mud product is screened out, and the remaining products are qualified particle sizes of -40 mesh to +200 mesh.

4. The method for efficient lithium extraction and high-purity quartz extraction from low-grade hydrothermal alteration lithium ore according to claim 1, characterized in that, In step (4), the stirring, scrubbing, settling and desliming process involves mixing and scrubbing the raw ore with coarse sand of -40 mesh to +200 mesh after screening and regrinding with coarse sand of -40 mesh to +200 mesh in an XFD12 scrubbing machine. The scrubbing slurry concentration is 50% and the scrubbing time is 30 minutes. Fine mud is extracted by siphon settling until the slurry is clear.

5. The method for efficient lithium extraction and high-purity quartz extraction from low-grade hydrothermal alteration lithium ore according to claim 1, characterized in that, In step (5), the weak magnetic separation is a single-stage wet weak magnetic separation with a magnetic field strength of 1500~2000 Oe; in step (6), the strong magnetic separation is a single-stage high-gradient magnetic separation with a magnetic field strength of 1.2~1.8T.

6. The method for efficient lithium extraction and high-purity quartz extraction from low-grade hydrothermal alteration lithium ore according to claim 1, characterized in that, In step (7), the reverse flotation separation is aerated flotation, the flotation machine is an XFD12 multi-cell flotation machine, and the process conditions are as follows: adjust the pH of the pulp to 2~3, the acid used to adjust the pH is one or a mixture of sulfuric acid, oxalic acid, nitric acid, and hydrochloric acid, the reverse flotation pulp concentration is 15~30%, the collector dosage is 400~600g / t, the frother dosage is 50~100g / t, the stirring rate is 800~1200r / min, and the flotation time is 2~5min; the collector is a mixture of compound amine, fatty acid, and silicate inhibitor, and the frother is a mixture of hydrocarbon oil and pine oil.

7. The method for efficient lithium extraction and high-purity quartz extraction from low-grade hydrothermal alteration lithium ore according to claim 1, characterized in that, In step (8), the hot-press acid leaching process is at least one of ultrasonic acid leaching, stirring acid leaching, and heating acid leaching. The acid used is a mixed acid, which is a combination of two or more of hydrofluoric acid, nitric acid, hydrochloric acid, sulfuric acid, and oxalic acid. The leaching time is 4 to 24 hours.

8. The method for efficient lithium extraction and high-purity quartz extraction from low-grade hydrothermal alteration lithium ore according to claim 1, characterized in that, In step (9), the mud is combined: the -200 mesh fine mud screened from the original ore, the -200 mesh fine mud produced after re-grinding the +40 mesh, and the fine mud produced by stirring and scrubbing the qualified particle size of -40 mesh to +200 mesh are combined into total mud.

9. The method for efficient lithium extraction and high-purity quartz extraction from low-grade hydrothermal alteration lithium ore according to claim 1, characterized in that, In step (10), the low-temperature lithium extraction is as follows: the processing temperature is 100~200℃, the lithium extraction reagent is a diluted acid with a concentration of 30%~75%, the heat preservation time is 1~5h, the water immersion stirring time is 0.5~1h, the water immersion stirring temperature is 20~90℃, and the immersion residue is filtered and rinsed until neutral.

10. The method for efficient lithium extraction and high-purity quartz extraction from low-grade hydrothermal alteration lithium ore according to claim 1, characterized in that, In step (11), lithium was measured in the leaching residues by ICP-AES and the lithium leaching rate was calculated. The SiO2, Al2O3, Fe2O3, K2O and Na2O indicators were detected in the mica leaching residues and feldspar leaching residues.

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