A method for separating feldspar and photovoltaic glass quartz sand from lithium mica tailings

Abstract

The application provides a method for separating feldspar and photovoltaic glass quartz sand from lithium mica tailings, and belongs to the field of tailings separation. The method comprises the following steps: mixing lithium mica tailings with water to obtain lithium mica tailings slurry, screening and magnetic separation of the lithium mica tailings slurry to obtain magnetic separation concentrate, mixing the magnetic separation concentrate with water to obtain magnetic separation concentrate slurry, mixing the magnetic separation concentrate slurry with an alkaline collector and carrying out flotation to obtain first-stage flotation feldspar and rough separation quartz sand, mixing the rough separation quartz sand with water to obtain rough separation quartz sand slurry, mixing the rough separation quartz sand slurry with an acidic collector and carrying out flotation to obtain second-stage feldspar and quartz sand, mixing the quartz sand with water to obtain quartz sand slurry, mixing the quartz sand slurry with an acidic collector and carrying out flotation to obtain third-stage feldspar and photovoltaic glass quartz sand. The feldspar and quartz sand are effectively separated from the tailings sand by designing a production process and selecting a suitable collector, and the resource use range is greatly widened.

Description

Technical Field

[0001] This invention relates to the field of tailings separation, and in particular to a method for separating feldspar and photovoltaic glass quartz sand from lepidolite tailings. Background Technology

[0002] With the explosive growth of new energy electric vehicles, lithium batteries have been widely used due to their high energy storage capacity and light weight. Lithium, one of the core materials of lithium batteries, must be obtained from nature through mineral processing. Lithium extraction from lepidolite, brine from salt lakes, and spodumene are currently the three main lithium extraction routes globally.

[0003] Yichun, Jiangxi Province, is known as the "Lithium Capital of Asia," boasting the world's largest polymetallic associated lepidolite mine. Its proven reserves currently account for approximately 40% of China's lepidolite reserves. Due to the low grade of lepidolite ore, the lithium oxide content (lithium oxide content) in Jiangxi ranges from 0.4-0.6% to 0.2-0.3%. Generally, producing 1 ton of lithium carbonate (a cathode material for power batteries) requires 150-200 tons of raw ore. A production of 500,000 tons of lithium carbonate will generate approximately 75 million to 100 million tons of tailings. With the rapid growth in demand for lithium carbonate from the electric vehicle industry, the scale of lithium mining and extraction is continuously expanding, and the amount of lepidolite tailings is increasing at an even faster pace. If this massive amount of tailings cannot be disposed of in a timely manner, it will inevitably affect the expansion of mining production and put enormous pressure on the local environmental ecology.

[0004] To address global climate change, my country plans to increase the total installed capacity of wind and solar power to over 1.2 billion kilowatts by 2030.

[0005] After years of effort, my country's solar photovoltaic manufacturing industry has achieved a dominant position in the global supply chain. Photovoltaic glass, as a crucial component of the photovoltaic industry, plays two core roles: protecting solar cells and transmitting light. China is already the world's largest producer of photovoltaic glass, accounting for over 90% of global production capacity, with a compound annual growth rate of 10.3% from 2016 to 2021. As a primary raw material for photovoltaic glass production, the demand for quartz sand has grown in tandem. Industry standards generally require over 60% quartz sand per ton of photovoltaic glass output.

[0006] The main components of lepidolite tailings are feldspar and quartz sand. Due to their mixed composition, they can generally only be used as raw materials for ordinary kaolin clay. Other technologies cannot effectively separate them, limiting their application scope and local consumption capacity. They have no added value and put enormous pressure on the local mining industry and the ecological environment. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides a method for separating feldspar and photovoltaic glass quartz sand from lepidolite tailings. By designing the production process and selecting a suitable collector, this invention effectively separates feldspar and quartz sand from the tailings sand, greatly expanding the scope of resource applications.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] This invention provides a method for separating feldspar and photovoltaic glass quartz sand from lepidolite tailings, comprising the following steps:

[0010] 1) Mix lepidolite tailings with water to obtain lepidolite tailings slurry;

[0011] 2) The lithium mica tailings slurry obtained in step 1) is screened by a vibrating screen to separate tailings sand with a particle size of less than 0.55 mm, and then screened by a hydraulic classifier to separate tailings sand with a particle size of more than 0.075 mm. Finally, it is subjected to magnetic separation to obtain magnetically separated fine sand.

[0012] 3) Mix the magnetically separated fine sand obtained in step 2) with water to obtain magnetically separated fine sand slurry. Adjust the pH value of the magnetically separated fine sand slurry to 10-13, mix it with an alkaline collector, and float it to obtain a first-stage flotation feldspar and coarse quartz sand.

[0013] The alkaline collector comprises the following components in weight percentage: n-undecane 29.463%, 2-butylpyridine 6.649%, n-dodecylamine 7.22%, n-undecylonitrile 33.635%, 3-methyl,1′-biphenyl 0.836%, 2-hydroxyphenazine 3.885%, 1-isocyanododecane 13.519%, and N-octylacetamide 4.793%;

[0014] 4) Mix the coarse quartz sand obtained in step 3) with water to obtain coarse quartz sand slurry. Adjust the pH value of the coarse quartz sand slurry to 1.5-4, mix it with an acidic collector, and float it to obtain feldspar and quartz sand.

[0015] The acidic collector comprises the following components in weight percentage: dodecane-2-amine 62.256%, heptadecane 0.533%, stearamide 2.802%, (E)-5-((5-phenylfuran-2-yl)methylene)furan-2(5H)-one 15.294%, di(4-isocyanophenyl)methane 3.053%, and (E)-N-(4-(3-carbonyl) 4.169% of N-(1-isopropyl-1H-pyrazol-4-yl)-2-(4-nitro-1H-pyrazol-1-yl)acetamide, 6.509% of docosylamine, and 1.572% of 8-(prop-1-en-2-yl)-2H-furano[2,3-h]chromene-2-one;

[0016] 5) Mix the quartz sand obtained in step 4) with water to obtain quartz sand slurry. Adjust the pH value of the quartz sand slurry to 1.5-4, mix with an acidic collector, and float to obtain feldspar and photovoltaic glass quartz sand.

[0017] Preferably, in step 1), the mass ratio of lithium mica tailings to water is 30:70.

[0018] Preferably, the number of times the magnetic separation is performed in step 2) is 2, and the conditions for the magnetic separation include: the magnetic field strength of the vertical ring is 1.2T.

[0019] Preferably, in step 3), the mass ratio of magnetically separated fine sand to water is 25:75, and sodium hydroxide is used to adjust the pH value of the magnetically separated fine sand slurry.

[0020] Preferably, the amount of alkaline collector used in step 3) is 3.67 kg / t.

[0021] Preferably, in step 4), the mass ratio of coarse quartz sand to water is 25:75, and sulfuric acid is used to adjust the pH value of the coarse quartz sand slurry.

[0022] Preferably, the amount of acidic collector used in step 4) is 2.11 kg / t.

[0023] Preferably, in step 5), the mass ratio of quartz sand to water is 25:75, and sulfuric acid is used to adjust the pH value of the quartz sand slurry.

[0024] Preferably, the amount of acidic collector used in step 5) is 2.11 kg / t.

[0025] The beneficial effects of this invention are as follows:

[0026] This invention, through the design of a production process and the selection of suitable collectors, effectively separates feldspar and photovoltaic glass quartz sand from tailings, greatly expanding the scope of resource applications. The quartz sand, usable in photovoltaic glass production, will provide the photovoltaic glass industry with a large, stable, and reliable supply of raw materials, while high-quality feldspar can be used in the glass and ceramics industries. In this way, the problem of large-scale production of lepidolite tailings with nowhere to dispose of it is solved, significantly increasing its added value and maximizing the value of tailings while optimizing resource utilization.

[0027] When this invention is put into practical production, lithium mica tailings are effectively treated, which not only solves the concerns about lithium extraction from mining and supports the development of the new energy electric vehicle industry, but also provides raw materials for the solar photovoltaic industry, thus safeguarding the realization of green and low-carbon energy goals. It can be described as killing two birds with one stone. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the embodiments will be briefly described below.

[0029] Figure 1 A flowchart for separating feldspar and photovoltaic glass quartz sand from lepidolite tailings. Detailed Implementation

[0030] This invention provides a method for separating feldspar and photovoltaic glass quartz sand from lepidolite tailings, comprising the following steps:

[0031] 1) Mix lepidolite tailings with water to obtain lepidolite tailings slurry;

[0032] 2) The lithium mica tailings slurry obtained in step 1) is screened by a vibrating screen to separate tailings sand with a particle size of less than 0.55 mm, and then screened by a hydraulic classifier to separate tailings sand with a particle size of more than 0.075 mm. Finally, it is subjected to magnetic separation to obtain magnetically separated fine sand.

[0033] 3) Mix the magnetically separated fine sand obtained in step 2) with water to obtain magnetically separated fine sand slurry. Adjust the pH value of the magnetically separated fine sand slurry to 10-13, mix it with an alkaline collector, and float it to obtain a first-stage flotation feldspar and coarse quartz sand.

[0034] The alkaline collector comprises the following components in weight percentage: n-undecane 29.463%, 2-butylpyridine 6.649%, n-dodecylamine 7.22%, n-undecylonitrile 33.635%, 3-methyl,1′-biphenyl 0.836%, 2-hydroxyphenazine 3.885%, 1-isocyanododecane 13.519%, and N-octylacetamide 4.793%;

[0035] 4) The coarse quartz sand obtained in step 3) is mixed with water to obtain coarse quartz sand slurry. The pH value of the coarse quartz sand slurry is adjusted to 1.5-4, mixed with an acidic collector, and floated to obtain feldspar and quartz sand.

[0036] The acidic collector comprises the following components in weight percentage: dodecane-2-amine 62.256%, heptadecane 0.533%, stearamide 2.802%, (E)-5-((5-phenylfuran-2-yl)methylene)furan-2(5H)-one 15.294%, di(4-isocyanophenyl)methane 3.053%, and (E)-N-(4-(3-carbonyl) 4.169% of N-(1-isopropyl-1H-pyrazol-4-yl)-2-(4-nitro-1H-pyrazol-1-yl)acetamide, 6.509% of docosylamine, and 1.572% of 8-(prop-1-en-2-yl)-2H-furano[2,3-h]chromene-2-one;

[0037] 5) Mix the quartz sand obtained in step 4) with water to obtain quartz sand slurry. Adjust the pH value of the quartz sand slurry to 1.5-4, mix with an acidic collector, and float to obtain feldspar and photovoltaic glass quartz sand.

[0038] This invention mixes lepidolite tailings with water to obtain a lepidolite tailings slurry. The source of the lepidolite tailings is not specifically limited in this invention. In this invention, the preferred mass ratio of lepidolite tailings to water is 30:70.

[0039] In this invention, the obtained lithium mica tailings slurry is screened by a vibrating screen to separate tailings sand with a particle size of less than 0.55 mm, and then screened by a hydraulic classifier to separate tailings sand with a particle size of greater than 0.075 mm. Finally, it undergoes magnetic separation to obtain magnetically separated fine sand. In this invention, the magnetic separation is preferably performed twice, and the preferred conditions for magnetic separation include a vertical ring magnetic field strength of 1.2 T.

[0040] This invention involves mixing the obtained magnetically separated fine sand with water to obtain a magnetically separated fine sand slurry. The pH of the slurry is adjusted to 10-13, and then mixed with an alkaline collector and floated to obtain first-stage flotation of feldspar and rougher quartz sand. Preferably, the pH of the magnetically separated fine sand slurry is adjusted to 11.5. In this invention, the alkaline collector comprises the following components in weight percentages: n-undecane 29.463%, 2-butylpyridine 6.649%, n-dodecylamine 7.22%, n-undecylonitrile 33.635%, 3-methyl,1′-biphenyl 0.836%, 2-hydroxyphenazine 3.885%, 1-isocyanododecane 13.519%, and N-octylacetamide 4.793%. In this invention, the alkaline collector serves to obtain first-stage flotation of feldspar and rougher quartz sand.

[0041] In this invention, the preferred mass ratio of the magnetically separated fine sand to water is 25:75, and sodium hydroxide is preferably used to adjust the pH value of the magnetically separated fine sand slurry.

[0042] This invention mixes the obtained coarsely selected quartz sand with water to obtain a coarsely selected quartz sand slurry. The pH of the coarsely selected quartz sand slurry is adjusted to 1.5-4, and then mixed with an acidic collector and floated to obtain feldspar and quartz sand. Preferably, the pH of the coarsely selected quartz sand slurry is adjusted to 2.5. Adjusting the pH enhances the activity of the collector. In this invention, the mass ratio of the coarsely selected quartz sand to water is preferably 25:75. Sulfuric acid is preferably used to adjust the pH of the coarsely selected quartz sand slurry. In this invention, the acidic collector comprises the following components in the following mass percentages: dodecane-2-amine 62.256%, heptadecane 0.533%, stearamide 2.802%, (E)-5-((5-phenylfuran-2-yl)methylene)furan-2(5H)-one 15.294%, di(4-isocyanophenyl)methane 3.053%, (E)-N-(4-( The composition includes 4.169% 3-carbonyl-3-(pyridin-2-yl)prop-1-enyl)phenyl)acetamide, 3.812% N-(1-isopropyl-1H-pyrazol-4-yl)-2-(4-nitro-1H-pyrazol-1-yl)acetamide, 6.509% docetylatedamine, and 1.572% 8-(prop-1-en-2-yl)-2H-furano[2,3-h]chromene-2-one. In this invention, the preferred amount of the acidic collector is 2.11 kg / t. In this invention, the function of the acidic collector is to obtain feldspar and quartz sand.

[0043] This invention involves mixing the obtained quartz sand with water to obtain a quartz sand slurry. The pH of the quartz sand slurry is adjusted to 1.5–4, and then mixed with an acidic collector and floated to obtain feldspar and photovoltaic glass quartz sand. In this invention, the preferred mass ratio of quartz sand to water is 25:75, and sulfuric acid is preferably used to adjust the pH of the quartz sand slurry. This invention improves the purity of the feldspar through two acidic collection processes.

[0044] To further illustrate the present invention, the following detailed description is provided in conjunction with embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0045] Example 1

[0046] The selected material is lepidolite tailings from Jiangxi Yichun Jiuling Lithium Industry Co., Ltd. The Yichun lepidolite mine is located in the same geological metallogenic belt, and the lepidolite tailings from this lithium company are highly representative of different mining sites in the same region.

[0047] The lithium mica tailings of the lithium company are transported from the stockpile to the production site by a loader, added to the silo, and discharged by a belt scale and mixed with water in the slurry pool.

[0048] The slurry is pumped to a double-layer grading vibrating screen for coarse and fine screening. Coarse sand with a diameter of +0.55mm (+ indicates larger than the particle size, - indicates smaller than the particle size) is screened out of the production line. This portion of coarse sand accounts for 3.80% of the lithium mica tailings entering the production line and is recycled separately.

[0049] The slurry from the vibrating screen enters the hydraulic classifier under gravity flow, and the tailings sand of -0.55mm to +0.075mm is screened out. The fine sand of -0.075mm accounts for 19.74% of the mass of the lepidolite tailings and is removed from the production line for separate recycling.

[0050] Tailings sand that meets the flotation fineness requirements enters a 1.2T high-intensity magnetic separator. After two magnetic separation stages, the iron content is reduced to obtain magnetically separated fine sand. Measuring shows that the magnetically separated tailings account for 1.23% of the lepidolite tailings by mass, and this tailings are removed from the production line for separate recycling.

[0051] The magnetically separated fine sand enters the flotation cell. The pH of the slurry is adjusted to 11.5 with NaOH, and 3.67 kg / t of alkaline collector (based on the lepidolite tailings entering the production line) is added for flotation. Rougher quartz sand and first-stage flotation feldspar are separated. The first-stage flotation feldspar accounts for 26.33% of the mass of the lepidolite tailings and enters the finished product silo for further processing.

[0052] Table 1. Components (mass percentage) of alkaline collectors

[0053] Serial Number Substance Name content(%) 1 n-Undecane 29.463 2 2-Butylpyridine 6.649 3 dodecylamine 7.22 4 undecanoic acid 33.635 5 3-Methyl,1′-biphenyl 0.836 6 2-Hydroxyphenazine 3.885 7 1-Isocyanododecane 13.519 8 N-Ocylacetamide 4.793

[0054] The roughed quartz sand enters the next flotation cell. The slurry is adjusted to pH 2.5 with sulfuric acid, and 2.11 kg / t of acidic collector water (based on the lepidolite tailings entering the production line) is added for flotation. Quartz sand and feldspar from the second-stage flotation are separated. The feldspar from the second-stage flotation is measured to account for 12.00% of the mass of the lepidolite tailings and enters the finished product silo for further processing.

[0055] Table 2. Components (mass percentage) of acidic collectors

[0056]

[0057]

[0058] The quartz sand enters the next flotation cell. The slurry is adjusted to pH 2.5 with sulfuric acid, and 2.11 kg / t of acidic collector (based on the lepidolite tailings entering the production line) is added for flotation. Photovoltaic glass quartz sand and three-stage flotation feldspar are separated. The three-stage flotation feldspar accounts for 10.92% of the lepidolite tailings by mass and enters the finished product silo for further processing. The photovoltaic glass quartz sand (25.98% of the lepidolite tailings by mass) also enters the finished product silo for further processing.

[0059] The obtained first, second, and third sections, as well as the photovoltaic glass quartz sand, were sent to Foshan Ceramic Research Institute Testing Co., Ltd. for testing. The results are shown in Table 3.

[0060] Table 3 Detection Results

[0061]

[0062] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for separating feldspar and photovoltaic glass quartz sand from lepidolite tailings, characterized in that, The following steps are required: 1) Mix lepidolite tailings with water to obtain lepidolite tailings slurry; 2) The lithium mica tailings slurry obtained in step 1) is screened by a vibrating screen to separate tailings sand with a particle size of less than 0.55 mm, and then screened by a hydraulic classifier to separate tailings sand with a particle size of more than 0.075 mm. Finally, it is subjected to magnetic separation to obtain magnetically separated fine sand. 3) Mix the magnetically separated fine sand obtained in step 2) with water to obtain magnetically separated fine sand slurry. Adjust the pH value of the magnetically separated fine sand slurry to 11.5, mix it with an alkaline collector, and float it to obtain a first-stage flotation feldspar and coarsely selected quartz sand. The alkaline collector comprises the following components in weight percentage: n-undecane 29.463%, 2-butylpyridine 6.649%, n-dodecylamine 7.22%, n-undecylonitrile 33.635%, 3-methyl,1′-biphenyl 0.836%, 2-hydroxyphenazine 3.885%, 1-isocyanododecane 13.519%, and N-octylacetamide 4.793%; 4) Mix the coarse quartz sand obtained in step 3) with water to obtain coarse quartz sand slurry. Adjust the pH value of the coarse quartz sand slurry to 2.5, mix it with an acidic collector, and float it to obtain feldspar and quartz sand. The acidic collector comprises the following components in weight percentage: dodecane-2-amine 62.256%, heptadecane 0.533%, stearamide 2.802%, (E)-5-((5-phenylfuran-2-yl)methylene)furan-2(5H)-one 15.294%, di(4-isocyanophenyl)methane 3.053%, and (E)-N-(4-(3-carbonyl) -3-(pyridin-2-yl)prop-1-enyl)phenyl)acetamide 4.169%, N-(1-isopropyl-1H-pyrazol-4-yl)-2-(4-nitro-1H-pyrazol-1-yl)acetamide 3.812%, docosylamine 6.509% and 8-(prop-1-en-2-yl)-2H-furano[2,3-h]chromene-2-one 1.572%; 5) Mix the quartz sand obtained in step 4) with water to obtain quartz sand slurry, adjust the pH value of the quartz sand slurry to 2.5, mix with acidic collector, and float to obtain feldspar and photovoltaic glass quartz sand; In step 1), the mass ratio of lithium mica tailings to water is 30:

70. Step 2) involves magnetic separation twice, and the conditions for magnetic separation are: a vertical ring magnetic field strength of 1.2T. In step 3), the mass ratio of magnetically separated fine sand to water is 25:75, and sodium hydroxide is used to adjust the pH value of the magnetically separated fine sand slurry. The amount of alkaline collector used in step 3) is 3.67 kg / t; In step 4), the mass ratio of coarse quartz sand to water is 25:75, and sulfuric acid is used to adjust the pH value of the coarse quartz sand slurry. In step 4), the amount of acidic collector used is 2.11 kg / t. In step 5), the mass ratio of quartz sand to water is 25:75, and sulfuric acid is used to adjust the pH value of the quartz sand slurry. In step 5), the amount of acidic collector used is 2.11 kg / T.

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