Beneficiation method of calcium carbonate type clay lithium ore

Abstract

This application provides a beneficiation method for calcium carbonate-type clay lithium ore, relating to the field of mineral processing. The beneficiation method includes: mixing calcium carbonate-type clay lithium ore with sodium hydroxide, stirring, and screening to obtain coarse and fine particle products; the coarse particle product is used as the first tailings; the fine particle product undergoes desliming treatment to obtain overflow and underflow products, the overflow product being the first lithium-bearing concentrate, and the underflow product undergoing reverse flotation decalcification treatment to obtain a calcium-bearing product and a lithium-bearing rough concentrate; the calcium-bearing product is used as the second tailings; the lithium-bearing rough concentrate undergoes reverse enrichment to obtain a second lithium-bearing concentrate and a third tailings; the first and second lithium-bearing concentrates are combined to form a lithium-bearing concentrate product. The beneficiation method for calcium carbonate-type clay lithium ore provided in this application employs a novel beneficiation method of selective liberation of the raw clay lithium ore – screening – hydrocyclone desliming – reverse flotation decalcification – centrifuge reverse enrichment of flotation tailings, which can obtain beneficiation indicators with a Li₂O grade greater than 0.80% and a recovery rate greater than 70%.

Description

Technical Field

[0001] This application relates to the field of mineral processing, and more particularly to a method for processing calcium carbonate-type clay lithium ore. Background Technology

[0002] Lithium is widely used in new energy batteries, nuclear industry, aerospace and other fields. Currently, the lithium resources mined and utilized in my country mainly include brine deposits and pegmatite deposits. However, due to the large-scale mining of pegmatite lithium deposits, resources are becoming increasingly scarce; lithium extraction technology from salt lakes is difficult and costly, and conventional lithium mines (pegmatite and brine types) cannot meet the demand for lithium.

[0003] In recent years, a new type of lithium deposit has been gradually discovered and recognized. Unlike brine lithium deposits and pegmatite-type lithium deposits, lithium is also contained in clay minerals, and the reserves are abundant. Calcium carbonate-type clay lithium deposits are mainly composed of quartz, calcite, lithium chlorite, kaolinite, and illite. Lithium is primarily found in lithium chlorite, with a Li₂O content of approximately 0.57%. Factors affecting lithium recovery include the generally fine particle size of lithium chlorite and its close relationship with quartz and calcite. Furthermore, some kaolinite and illite are often interbedded with lithium chlorite, making separation difficult and resulting in generally poor beneficiation and enrichment effects. Lithium extraction from clay lithium minerals often employs direct smelting processes, which suffer from problems such as large slag volume, high energy consumption, high consumption of complex sulfates / sulfuric acid, and high pollution. Therefore, there is an urgent need to develop a new beneficiation method to maximize lithium enrichment in lithium resources and reduce the processing scale of downstream smelting enterprises.

[0004] Preliminary explorations have been conducted on this type of clay-lithium ore, primarily employing hydrometallurgical methods for direct lithium extraction. This involves leaching, purification, lithium precipitation, and refining to obtain battery-grade lithium carbonate. Producing one ton of lithium salt often yields hundreds of tons of leaching residue, presenting problems such as large smelting slag volume, extremely high energy consumption, high consumption of complex sulfates / sulfuric acid, and high pollution. For example, patent CN202010684178.8 discloses a method for extracting lithium from lithium-containing clay. This method involves ball milling the lithium clay, then mixing it with calcium carbonate, sodium sulfate, and potassium sulfate in a certain proportion, roasting it, pulverizing it, and leaching it to obtain a lithium-containing solution. However, this method produces a large amount of leaching residue with a lithium oxide content reaching 0.2%, making it only suitable for clay ores with a high lithium oxide grade.

[0005] Traditional single-stage beneficiation processes suffer from problems such as high grinding power consumption, significant mud formation, high reagent consumption, and poor separation. For example, patent CN 115999758 A discloses a beneficiation method for lithium clay ore, which reduces power consumption in the crushing stage through a multi-crushing, multi-grinding process. However, this method still inevitably consumes energy through regrinding of middlings. Patent CN115418498 A discloses a treatment method for carbonate lithium clay, which uses a process flow of scrubbing-screening secondary separation-separation of different particle components through stepwise desulfurization and decarbonization-calcite removal-lithium flotation. However, the flotation process is long, requires a variety of reagents, and consumes a large amount of reagents, which seriously restricts the industrial development and application of carbonate clay lithium ore. Summary of the Invention

[0006] The purpose of this application is to provide a beneficiation method for calcium carbonate-type clay lithium ore to solve the above-mentioned problems.

[0007] To achieve the above objectives, this application adopts the following technical solution:

[0008] A beneficiation method for calcium carbonate-type clay lithium ore, comprising:

[0009] Calcium carbonate clay lithium ore and sodium hydroxide are mixed, stirred and then sieved to obtain coarse and fine particle products; the coarse particle product is used as the first tailings.

[0010] Fine particles are deslimed to obtain overflow product and underflow product. The overflow product is the first lithium-containing concentrate. The underflow product is decalcified by reverse flotation to obtain calcium-containing product and lithium-containing rough concentrate. The calcium-containing product is used as the second tailings.

[0011] The lithium-containing crude concentrate is subjected to reverse enrichment to obtain a second lithium-containing concentrate and a third tailings;

[0012] The first lithium-containing concentrate and the second lithium-containing concentrate are combined into a lithium-containing concentrate product.

[0013] Preferably, the mass ratio of sodium hydroxide to calcium carbonate clay lithium ore is 1:(1000-2000).

[0014] Preferably, the ratio of the feed amount of the calcium carbonate type clay lithium ore to the stirring volume is 600g:(1000-2000)ml, the stirring rate is 1000-2000r / min, and the stirring time is 10-100min.

[0015] Preferably, the coarse particle product is a particle with a particle size greater than 0.074 mm.

[0016] Preferably, the desliming process is carried out using a hydrocyclone with an aperture of 0.5-1.5 mm.

[0017] Preferably, a pH adjuster is added during the reverse flotation decalcification process, the pH adjuster comprising sodium hydroxide and / or sodium carbonate.

[0018] Preferably, the mass ratio of sodium hydroxide to sodium carbonate is (0-2000):(0-1000).

[0019] Preferably, collector BK428 is added during the reverse flotation decalcification treatment;

[0020] The collector BK428 comprises, by weight, 45-51 parts of oxidized paraffin soap, 5-9 parts of oleic acid and 5-10 parts of C12.

[0021] Preferably, the reverse enrichment is carried out using a Nelson centrifuge, with a single feed rate of 30-50g.

[0022] Preferably, the upward water flow of the Nelson centrifuge is set to 30-50 kPa and the rotation speed is 40-120 G.

[0023] Compared with the prior art, the beneficial effects of this application include:

[0024] The beneficiation method for calcium carbonate-type clay lithium ore provided in this application involves mixing and stirring calcium carbonate-type clay lithium ore with sodium hydroxide, and using a combination of sodium hydroxide dissolution and flotation stirring to achieve selective liberation of clay lithium minerals such as lithium chlorite from quartz and feldspar. This method replaces the traditional ball milling process, avoids mud formation in the raw clay lithium ore, and reduces overall energy consumption. Fine particles undergo desliming treatment, effectively increasing the Li2O enrichment ratio, which is beneficial for improving the efficiency of high-pressure leaching in smelting. This solves the problems of large slag volume, extremely high energy consumption, and high consumption of complex sulfates / sulfuric acid in direct smelting of clay lithium. The underflow product is decalcified by reverse flotation to reduce the calcium impurity content in the product, with a calcium removal rate of over 70%, achieving further enrichment of lithium. The lithium rough concentrate slurry undergoes reverse enrichment, utilizing the different centrifugal accelerations obtained by minerals due to their different densities to achieve enrichment through ultragravity separation.

[0025] The beneficiation method for calcium carbonate clay lithium ore provided in this application adopts a new beneficiation method of selective liberation of raw clay lithium ore - screening - hydrocyclone desliming - reverse flotation decalcification of sand and sand - centrifuge re-enrichment of flotation tailings, which can obtain beneficiation indicators with Li2O grade greater than 0.80% and recovery rate greater than 70%. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.

[0027] Figure 1 A schematic diagram of the process flow for the beneficiation method of calcium carbonate-type clay lithium ore provided in the embodiments. Detailed Implementation

[0028] As used in this article:

[0029] "Prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0030] The conjunction "composed of..." excludes any unspecified elements, steps, or components. If used in a claim, this phrase makes the claim closed, excluding materials other than those described, except for associated conventional impurities. When the phrase "composed of..." appears in a clause of the body of a claim rather than immediately following it, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0031] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1–5” is disclosed, the described range should be interpreted as including ranges “1–4”, “1–3”, “1–2”, “1–2 and 4–5”, “1–3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0032] In these embodiments, unless otherwise specified, the portions and percentages are all by weight.

[0033] "Parts by mass" refers to the basic unit of measurement that expresses the mass ratio of multiple components. One part can represent any unit mass, such as 1g or 2.689g. If we say that component A has "a" parts by mass and component B has "b" parts by mass, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it can mean that the mass of component A is aK and the mass of component B is bK (K is any number representing a multiplier). It is important to understand that, unlike the number of parts by mass, the sum of the mass parts of all components is not limited to 100 parts.

[0034] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0035] A beneficiation method for calcium carbonate-type clay lithium ore, comprising:

[0036] Calcium carbonate clay lithium ore and sodium hydroxide are mixed, stirred and then sieved to obtain coarse and fine particle products; the coarse particle product is used as the first tailings.

[0037] Fine particles are deslimed to obtain overflow product and underflow product. The overflow product is the first lithium-containing concentrate. The underflow product is decalcified by reverse flotation to obtain calcium-containing product and lithium-containing rough concentrate. The calcium-containing product is used as the second tailings.

[0038] The lithium-containing crude concentrate is subjected to reverse enrichment to obtain a second lithium-containing concentrate and a third tailings;

[0039] The first lithium-containing concentrate and the second lithium-containing concentrate are combined into a lithium-containing concentrate product.

[0040] Sodium hydroxide acts on the surface of the raw clay lithium ore, selectively dissolving the interface between the clay lithium chlorite and quartz and feldspar, and achieving selective dissociation under the mechanical stirring action of the flotation machine.

[0041] In an optional embodiment, the mass ratio of sodium hydroxide to calcium carbonate-type clay lithium ore is 1:(1000-2000).

[0042] Optionally, the mass ratio of sodium hydroxide to calcium carbonate-type clay lithium ore can be any value between 1:1000, 1:1100, 1:1200, 1:1300, 1:1400, 1:1500, 1:1600, 1:1700, 1:1800, 1:1900, 1:2000 or 1:(1000-2000).

[0043] In an optional embodiment, the ratio of the feed amount of the calcium carbonate type clay lithium ore to the volume of the stirring is 600g:(1000-2000)ml, the stirring rate is 1000-2000r / min, and the stirring time is 10-100min.

[0044] Optionally, the ratio of the feed rate of the calcium carbonate-type clay lithium ore to the stirring volume can be any value between 600g:1000ml, 600g:1100ml, 600g:1200ml, 600g:1300ml, 600g:1400ml, 600g:1500ml, 600g:1600ml, 600g:1700ml, 600g:1800ml, 600g:1900ml, 600g:2000ml, or 600g:(1000-2000)ml, and the stirring speed can be 1000r / m. The speed can be 1100 r / min, 1200 r / min, 1300 r / min, 1400 r / min, 1500 r / min, 1600 r / min, 1700 r / min, 1800 r / min, 1900 r / min, 2000 r / min or any value between 1000 and 2000 r / min, and the time can be any value between 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min or any value between 10 and 100 min.

[0045] In one optional embodiment, the coarse particle product is a particle with a size greater than 0.074 mm.

[0046] In an optional embodiment, the desliming process is carried out using a hydrocyclone with an orifice diameter of 0.5-1.5 mm.

[0047] Hydrocyclones were used to deslim particles as small as -0.074 mm. Experiments verified that, under hydrocyclone inlet diameter conditions of φ0.5 mm-1.5 mm, the overflow product grade was above 0.8%, and the recovery rate was above 53%. This effectively improved the Li₂O enrichment ratio, which is beneficial for improving the efficiency of high-pressure leaching in smelting, and solved the problems of large slag volume, extremely high energy, and high consumption of complex sulfates / sulfuric acid in direct clay lithium smelting.

[0048] In an optional embodiment, a pH adjuster, comprising sodium hydroxide and / or sodium carbonate, is added during the reverse flotation decalcification process.

[0049] In one optional embodiment, the mass ratio of sodium hydroxide to sodium carbonate is (0-2000):(0-1000).

[0050] Optionally, during the use of the pH adjuster, the mass ratio of sodium hydroxide to sodium carbonate can be any value between 0:1000, 100:1000, 1000:1000, 2000:1000, 2000:0, 2000:500, or (0-2000):(0-1000).

[0051] In an optional embodiment, collector BK428 is added during the reverse flotation decalcification process;

[0052] The collector BK428 comprises, by weight, 45-51 parts of oxidized paraffin soap, 5-9 parts of oleic acid and 5-10 parts of C12.

[0053] The C12 referred to in this application is dodecyl alcohol.

[0054] Optionally, in collector BK428, the amount of oxidized paraffin soap can be any value between 45, 46, 47, 48, 49, 50, 51, or 45-51 parts; the amount of oleic acid can be any value between 5, 6, 7, 8, 9, or 5-9 parts; and the amount of C12 can be any value between 5, 6, 7, 8, 9, 10, or 5-10 parts.

[0055] In one alternative implementation, the de-enrichment is carried out using a Nelson centrifuge with a single feed rate of 30-50g.

[0056] Optionally, the amount of ore fed at one time can be any value between 30g, 35g, 40g, 45g, 50g or 30-50g.

[0057] In the inverted conical inner sleeve of the Nelson centrifuge, the lithium crude concentrate slurry flows from the feed pipe to the bottom of the inner sleeve under the influence of gravity and mechanical force. Due to the high-speed rotation of the inner sleeve, the slurry experiences a large centrifugal force and flies out radially along the inner wall of the conical inner sleeve. Because the mineral particles are in the centrifugal force field generated by the high-speed rotation of the inverted conical body of the inner sleeve, the minerals, due to their different densities, receive different centrifugal accelerations, thus achieving supergravity separation and enrichment.

[0058] In one optional implementation, the Nelson centrifuge's upward water flow is set to 30-50 kPa and its rotational speed to 40-120 G.

[0059] Optionally, the rising water flow setting of the Nelson centrifuge can be any value between 30 kPa, 35 kPa, 40 kPa or 30-50 kPa, and the rotation speed can be any value between 40 G, 50 G, 60 G, 70 G, 80 G, 90 G, 100 G, 110 G, 120 G or 40-120 G.

[0060] The implementation schemes of this application will be described in detail below with reference to specific embodiments. However, those skilled in the art will understand that the following embodiments are only for illustrating this application and should not be regarded as limiting the scope of this application. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0061] First, the raw ore used in the embodiments of this application is described, as shown in Table 1 below:

[0062] Table 1 Composition of raw ore

[0063]

[0064] Example 1

[0065] like Figure 1 As shown in the figure, this embodiment provides a beneficiation method for calcium carbonate type clay lithium ore, which specifically includes the following steps:

[0066] Step 1) Feed 600g of clay-lithium ore and place it in a flotation machine for stirring. Selective dissolution with sodium hydroxide is used to improve the liberation of clay minerals from feldspar and quartz. The mass ratio of sodium hydroxide to clay-lithium ore is 1:1000. The stirring volume is 2000mL, the stirring rate is 1902r / min, and the stirring time is 30min. Larger clay-lithium ore particles are liberated through a combination of selective dissolution and mechanical stirring. The stirred product is then wet-screened using a 0.074mm aperture screen. The particles that cannot pass through the screen are treated as tailings 1.

[0067] Step 2) The fine particulate product is fed into a hydrocyclone for desliming. The hydrocyclone has a diameter of φ1.5mm, and overflow product and underflow product are obtained respectively.

[0068] Step 3) The underflow product is fed into a flotation machine for reverse flotation decalcification. The pH adjuster is Na2CO3 to NaOH at a mass ratio of 500:250. The calcite reverse flotation collector is BK428 containing 45 parts of 731 (oxidized paraffin soap), 5 parts of Hol (oleic acid), and 10 parts of C12. The reverse flotation decalcification process yields a calcium-containing product and a lithium-containing rough concentrate, with the calcium-containing product being treated as tailings 2.

[0069] Step 4) The lithium-containing crude concentrate is reverse enriched by a Nelson centrifuge with a single feed rate of 30g, an upward water flow setting of 50kPa, and a rotation speed of 120G.

[0070] Step 5) The overflow product is combined with lithium concentrate 2 to form the final lithium concentrate product.

[0071] Through experimental verification, a new beneficiation method using selective liberation of clay lithium ore, screening, hydrocyclone desliming, reverse flotation decalcification, and centrifugal re-enrichment of flotation tailings can achieve beneficiation results with a Li2O grade of 0.82% and a recovery rate of 73.15%.

[0072] Example 2

[0073] This embodiment provides a beneficiation method for calcium carbonate type clay lithium ore, specifically including the following steps:

[0074] Step 1) Feed 600g of clay-lithium ore and place it in a flotation machine for stirring. Selective dissolution with sodium hydroxide is used to improve the liberation of clay minerals from feldspar and quartz. The mass ratio of sodium hydroxide to clay-lithium ore is 1:1500. The stirring volume is 2000mL, the stirring rate is 1902r / min, and the stirring time is 30min. Larger clay-lithium ore particles are liberated through a combination of selective dissolution and mechanical stirring. The stirred product is then wet-screened using a 0.074mm aperture screen. The particles that cannot pass through the screen are treated as tailings 1.

[0075] Step 2) The fine particulate product is fed into a hydrocyclone for desliming. The hydrocyclone has a diameter of φ1.0mm, and overflow product and underflow product are obtained respectively.

[0076] Step 3) Underflow product 2 is fed into a flotation machine for reverse flotation decalcification. The pH adjuster is Na2CO3 to NaOH at a mass ratio of 500:500. The calcite reverse flotation collector is BK428 containing 45 parts of 731 (oxidized paraffin soap), 8 parts of Hol (oleic acid), and 5 parts of C12. The reverse flotation decalcification process yields a calcium-containing product and a lithium-containing rough concentrate, with the calcium-containing product being treated as tailings 2.

[0077] Step 4) The lithium-containing crude concentrate is reverse enriched by a Nelson centrifuge with a single feed rate of 30g, an upward water flow rate of 40kPa, and a rotation speed of 120G.

[0078] Step 5) The overflow product is combined with lithium concentrate 2 to form the final lithium concentrate product.

[0079] Through experimental verification, a new beneficiation method using selective liberation of clay lithium ore, screening, hydrocyclone desliming, reverse flotation decalcification, and centrifugal re-enrichment of flotation tailings can achieve beneficiation results with a Li2O grade of 0.80% and a recovery rate of 71.07%.

[0080] Example 3

[0081] This embodiment provides a beneficiation method for calcium carbonate type clay lithium ore, specifically including the following steps:

[0082] Step 1) Feed 600g of clay-lithium ore and place it in a flotation machine for stirring. Selective dissolution with sodium hydroxide is used to improve the liberation of clay minerals from feldspar and quartz. The mass ratio of sodium hydroxide to clay-lithium ore is 1:1800. The stirring volume is 2000mL, the stirring rate is 1902r / min, and the stirring time is 60min. Larger clay-lithium ore particles are liberated through a combination of selective dissolution and mechanical stirring. The stirred product is then wet-screened using a 0.074mm aperture screen. The particles that cannot pass through the screen are treated as tailings 1.

[0083] Step 2) The fine particulate product is fed into a hydrocyclone for desliming. The hydrocyclone has a diameter of φ1.0mm, and overflow product and underflow product are obtained respectively.

[0084] Step 3) Underflow product 2 is fed into a flotation machine for reverse flotation decalcification. The pH adjuster is Na2CO3 to NaOH at a mass ratio of 500:500. The calcite reverse flotation collector is BK428 containing 50 parts of 731 (oxidized paraffin soap), 10 parts of Hol (oleic acid), and 5 parts of C12. The reverse flotation decalcification process yields a calcium-containing product and a lithium-containing rough concentrate, with the calcium-containing product being treated as tailings 2.

[0085] Step 4) The lithium-containing crude concentrate is reverse enriched by a Nelson centrifuge with a single feed rate of 30g, an upward water flow setting of 50kPa, and a rotation speed of 120G.

[0086] Step 5) The overflow product is combined with lithium concentrate 2 to form the final lithium concentrate product.

[0087] Through experimental verification, a new beneficiation method using selective liberation of clay lithium ore, screening, hydrocyclone desliming, reverse flotation decalcification, and centrifugal re-enrichment of flotation tailings can achieve a Li2O grade of 0.81% and a recovery rate of 70.55%.

[0088] Example 4

[0089] This embodiment provides a beneficiation method for calcium carbonate type clay lithium ore, specifically including the following steps:

[0090] Step 1) Feed 600g of clay-lithium ore and place it in a flotation machine for stirring. Selective dissolution with sodium hydroxide is used to improve the liberation of clay minerals from feldspar and quartz. The mass ratio of sodium hydroxide to clay-lithium ore is 1:1800. The stirring volume is 2000mL, the stirring rate is 1799r / min, and the stirring time is 60min. Larger clay-lithium ore particles are liberated through a combination of selective dissolution and mechanical stirring. The stirred product is then wet-screened using a 0.074mm aperture screen. The particles that cannot pass through the screen are treated as tailings 1.

[0091] Step 2) The fine particulate product is fed into a hydrocyclone for desliming. The hydrocyclone has a diameter of φ1.5mm, and overflow product and underflow product are obtained respectively.

[0092] Step 3) Underflow product 2 is fed into a flotation machine for reverse flotation decalcification. The pH adjuster is Na2CO3 to NaOH at a mass ratio of 500:250. The calcite reverse flotation collector is BK428 containing 45 parts of 731 (oxidized paraffin soap), 8 parts of Hol (oleic acid), and 5 parts of C12. The reverse flotation decalcification process yields a calcium-containing product and a lithium-containing rough concentrate, with the calcium-containing product being treated as tailings 2.

[0093] Step 4) The lithium-containing crude concentrate is reverse enriched by a Nelson centrifuge with a single feed rate of 30g, an upward water flow rate of 30kPa, and a rotation speed of 120G.

[0094] Step 5) The overflow product is combined with lithium concentrate 2 to form the final lithium concentrate product.

[0095] Through experimental verification, a new beneficiation method using selective liberation of clay lithium ore, screening, hydrocyclone desliming, reverse flotation decalcification, and centrifugal re-enrichment of flotation tailings can achieve a Li2O grade of 0.80% and a recovery rate of 70.83%.

[0096] Comparative Example 1

[0097] The difference between Comparative Example 1 and Example 1 is that the amount of sodium hydroxide used in step 1) is 0.

[0098] Test results: The Li2O grade in Comparative Example 1 decreased by 0.05%, and the recovery rate decreased by 1.38%, which are the mineral processing indicators.

[0099] Comparative Example 2

[0100] The difference between Comparative Example 2 and Example 1 is that in step 3), the calcite reverse flotation collector is BK428 containing 45 parts of 731 (oxidized paraffin soap).

[0101] Test results: In Comparative Example 2, the Li2O grade increased by 0.02%, and the recovery rate decreased by 1.46%, which are the mineral processing indicators.

[0102] Comparative Example 3

[0103] The difference between Comparative Example 3 and Example 1 is that in step 4), the lithium-containing crude concentrate is reverse-enriched by a Nelson centrifuge at a speed of 0G.

[0104] Test results: The Li2O grade in Comparative Example 3 decreased by 0.08%, and the recovery rate increased by 1.21%, which are the mineral processing indicators.

[0105] Comparative Example 4

[0106] The difference between Comparative Example 4 and Example 1 is that in step 3), reverse flotation decalcification is performed, and the pH adjuster is Na2CO3 to NaOH in a mass ratio of 2500:2500.

[0107] Test results: The Li2O grade in Comparative Example 4 decreased by 0.06%, and the recovery rate decreased by 1.83%, which are the mineral processing indicators.

[0108] The beneficiation method for calcium carbonate-type clay lithium ore provided in this application utilizes a combined process of selective dissolution with sodium hydroxide and flotation stirring to achieve selective liberation of the raw clay lithium ore. This avoids traditional grinding processes, reduces energy consumption, and prevents over-grinding of the raw clay lithium ore. The method employs single reverse flotation decalcification combined with Nelson reverse enrichment technology to improve the enrichment ratio of the clay lithium ore, shortening the traditional flotation process while using fewer reagents and in lower quantities.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0110] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the foregoing claims, any of the claimed embodiments can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

Claims

1. A beneficiation method for calcium carbonate-type clay lithium ore, characterized in that, include: Calcium carbonate clay lithium ore and sodium hydroxide are mixed, stirred and then sieved to obtain coarse and fine particle products; the coarse particle product is used as the first tailings. Fine particles are deslimed to obtain overflow product and underflow product. The overflow product is the first lithium-containing concentrate. The underflow product is subjected to reverse flotation decalcification to obtain calcium-containing product and lithium-containing rough concentrate. The calcium-containing product is used as the second tailings. The lithium-containing crude concentrate is subjected to reverse enrichment to obtain a second lithium-containing concentrate and a third tailings; The first lithium-containing concentrate and the second lithium-containing concentrate are combined into a lithium-containing concentrate product; The mass ratio of sodium hydroxide to calcium carbonate-type clay lithium ore is 1:(1000-2000). The ratio of the feed rate of the calcium carbonate type clay lithium ore to the stirring volume is 600g:(1000-2000)ml, the stirring rate is 1000-2000r / min, and the stirring time is 10-100min. Collector BK428 is added during the reverse flotation decalcification process; The collector BK428 comprises, by weight, 45-51 parts of oxidized paraffin soap, 5-9 parts of oleic acid, and 5-10 parts of C12; wherein the C12 is dodecyl alcohol. The reverse enrichment is carried out using a Nelson centrifuge, with a single feed rate of 30-50g. The upward water flow of the Nelson centrifuge is set to 30-50kPa, and the rotation speed is 40-120G.

2. The beneficiation method for calcium carbonate-type clay lithium ore according to claim 1, characterized in that, The coarse particle product is a particle with a size greater than 0.074 mm.

3. The beneficiation method for calcium carbonate-type clay lithium ore according to claim 1, characterized in that, The desliming process is carried out using a hydrocyclone with an orifice diameter of 0.5-1.5 mm.

4. The beneficiation method for calcium carbonate-type clay lithium ore according to claim 1, characterized in that, A pH adjuster is added during the reverse flotation decalcification process, and the pH adjuster includes sodium hydroxide and / or sodium carbonate.

5. The beneficiation method for calcium carbonate-type clay lithium ore according to claim 4, characterized in that, The mass ratio of sodium hydroxide to sodium carbonate is (0-2000):(0-1000).

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