A beneficiation method for enriching and recovering lithium from weathered clay-type lithium ore

Abstract

The application discloses a beneficiation method for enriching and recovering lithium from weathered clay type lithium ore. The beneficiation method comprises the following steps: S1, crushing the weathered clay type lithium ore to below 2 mm; S2, adding water to the crushed ore to form a slurry, and placing the slurry in a stirring container for full immersion and stirring; S3, performing first desliming on the slurry after the stirring in the step S2 to obtain fine mud 1 and sand 1; S4, performing secondary desliming on the sand 1 obtained in the step S3 by using ultrasonic treatment to obtain fine mud 2 and sand 2; S5, performing again desliming on the fine mud 1 obtained in the step S3 and the fine mud 2 obtained in the step S4 to obtain fine mud 3 and sand 3; and S6, performing reverse flotation on the sand 3 obtained in the step S5 to remove impurities and obtain lithium flotation concentrate, wherein the reverse flotation is performed for several times of cleaning by using 1 roughing and 1 scavenging to combine the froth. The method provided by the application can increase the Li2O grade of the weathered clay lithium concentrate to above 0.7%, and the recovery rate is above 70%.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, and in particular to a mineral processing method for enriching and recovering lithium from weathered clay-type lithium ore. Background Technology

[0002] Lithium is hailed as the "energy metal" of the 21st century and is currently widely used in the battery industry. With increasing global focus on carbon emissions, clean energy technologies are developing rapidly, leading to a surge in market demand for lithium and a corresponding rise in lithium prices. Lithium processing and extraction methods are also currently a hot research topic.

[0003] Currently, lithium is mainly extracted from salt lakes or hard-rock lithium ores. For ore extraction, the raw materials are primarily spodumene, lepidolite, and petalite. Spodumene concentrate contains 5%–7% Li₂O, lepidolite concentrate contains 1%–3% Li₂O, and petalite concentrate contains 3%–4% Li₂O. Higher Li₂O grades in lithium concentrate result in lower lithium salt production costs and less slag. Before 2020, lithium prices were low, and only spodumene could be used as a raw material for lithium extraction. With rising lithium prices, lithium extraction from lepidolite has become more widespread. For example, Yichun in Jiangxi Province has the world's largest lepidolite deposit, which is now fully developed.

[0004] Clay-type lithium resources, as a type of lithium ore, are abundant, but due to their special properties, they have not been well developed and utilized for a long time. Globally, clay-type resources are still in the research and development stage, but they have great potential in the long run and are of great significance in alleviating the lithium supply difficulties.

[0005] A certain area in Guizhou, my country, possesses abundant clay-type lithium deposits. Lithium is primarily found in lithium chlorite, along with significant amounts of illite, kaolinite, and other clay minerals. Other minerals include calcium carbonate, quartz, dolomite, and limonite. The ore distribution is extremely complex, with clay minerals forming a muddy cementation symbiosis, and gangue minerals filling the deposits in a honeycomb and network vein pattern. The surface weathered ore reserves are substantial, with the raw ore containing 0.5%–0.6% Li₂O and exhibiting extremely fine particle size, with approximately 90% containing particles smaller than 0.045 mm, making processing extremely difficult. Direct metallurgical extraction of lithium would result in enormous processing volumes, energy consumption, and slag production, hindering the development and utilization of this clay-type lithium deposit. Statistics show that for every 0.1% increase in Li₂O content, the waste slag produced per ton of lithium carbonate production decreases by approximately 18 tons. Therefore, employing beneficiation methods to improve the metallurgical grade of the input is crucial for the development of this clay-type lithium deposit. Summary of the Invention

[0006] The purpose of this invention is to provide a beneficiation method for enriching and recovering lithium from weathered clay-type lithium ore. The method proposed in this invention can increase the Li2O grade of weathered clay-type lithium concentrate to more than 0.7% and achieve a recovery rate of more than 70%.

[0007] This invention is achieved through the following technical solutions:

[0008] A beneficiation method for enriching and recovering lithium from weathered clay-type lithium ore, characterized by comprising the following steps:

[0009] S1. Crush the weathered clay-type lithium ore to below 2mm (-2mm);

[0010] S2. Add water to the ore crushed in step S1 to make a slurry with an ore mass concentration of 25% to 30%, and place it in a mixing container for thorough soaking and stirring;

[0011] S3. The slurry after stirring in step S2 is deslimed for the first time to obtain fine mud 1 and sediment 1. The particle size of fine mud 1 is controlled at 0.020~0.025mm.

[0012] S4. The sand 1 obtained in step S3 is treated with ultrasound to deslim it twice, and fine mud 2 and sand 2 are obtained. The particle size of fine mud 2 is controlled at 0.020~0.025mm.

[0013] S5. Combine the fine mud 1 obtained in step S3 with the fine mud 2 obtained in step S4 and deslim again to obtain fine mud 3 and sediment 3. The particle size of fine mud 3 is less than 0.010 mm.

[0014] S6. The sediment 3 obtained in step S5 is subjected to reverse flotation to remove impurities and obtain lithium flotation concentrate. The reverse flotation adopts one roughing and one scavenging froth combined for several cleaning processes. The amount of reverse flotation reagents is relative to the amount of weathered clay-type lithium ore in step S1. The reverse flotation modifier is sodium carbonate, with a total amount of 300-400 g / t. The depressant is water glass, with a total amount of 600-1200 g / t. The collector is fatty acid soap, with a total amount of 600-800 g / t.

[0015] Preferably, the weathered clay-type lithium ore described in step S1 is a surface weathered ore with a Li2O content of 0.5% to 0.6%.

[0016] Preferably, the stirring and soaking conditions in step S2 are: stirring speed of 600-1200 rpm and stirring and soaking time of 30-60 min.

[0017] Preferably, the ultrasonic treatment time in step S4 is 30 to 40 minutes.

[0018] Preferably, the reverse flotation in step S6 involves three stages of cleaning, including one roughing and one scavenging froth separation. The cleaned froth is the reverse flotation tailings, and the other products are lithium flotation concentrate. In this invention, the cleaning process is blank flotation.

[0019] Further preferred, the fine mud 3 and lithium flotation concentrate are used as lithium concentrate products.

[0020] Preferably, step S6, which involves coarse and scavenging, refers to adding sodium carbonate, water glass, and fatty acid soap sequentially to the sediment 3 for coarse selection, followed by adding fatty acid soap to the coarsely selected material for scavenging.

[0021] Preferably, the inhibitor mentioned in step S6 is water glass, and the dosage is 600-1000 g / t.

[0022] Preferably, the collector in step S6 is sodium fatty acid.

[0023] Compared with existing technologies, the outstanding advantages of this invention for weathered clay lithium deposits are:

[0024] 1. No grinding operation, saving beneficiation costs. This invention targets weathered clay-type lithium ore, characterized by the fact that various minerals are basically crushed during weathering, but due to the fine particle size, the minerals are in a muddy cemented symbiotic state, with honeycomb / vein filling. The stirring and soaking method proposed in this invention can effectively break the cementation of clay minerals; the ultrasonic treatment method proposed in this invention can effectively separate minerals in the honeycomb / vein filling state, thus achieving beneficiation without grinding.

[0025] 2. Multi-stage desliming enhances the recovery of fine-grained clay lithium. Lithium in clay lithium ore is mainly found in clay minerals. Weathered clay minerals disperse directly into fine mud in water, generally within the range of -0.010 mm. Minerals in this particle size are difficult to further purify through other beneficiation methods. Therefore, direct desliming is used to recover them, which is beneficial for lithium enrichment.

[0026] 3. Disposal of coarse-grained ore reduces subsequent processing volume. This invention directly discards the sand after secondary desliming. This coarse-grained ore is ultrasonically treated, and its surface is basically free of adhering clay minerals. It mainly consists of gangue with relatively high hardness and low Li2O content, and can be directly disposed of as waste.

[0027] 4. Intermediate particle size reverse flotation reduces flotation reagent consumption. This invention performs reverse flotation on the intermediate particle size (-0.025 + 0.010 mm), reducing the reagent consumption caused by fine minerals entering the flotation system. Furthermore, this particle size contains not only clay minerals but also a significant amount of gangue minerals that can be removed by flotation; therefore, the reverse flotation impurity removal effect is relatively good. Attached Figure Description

[0028] Figure 1 The above are process flow diagrams for embodiments 1-5 of the present invention. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions in the art or as recommended by the manufacturer; the raw materials and reagents used, unless otherwise specified, are considered to be commercially available through conventional markets. In Example 1 below, the mass ratio of sodium fatty acids used in the roughing and sweeping processes is 3:1.

[0030] Example 1

[0031] Reference Figure 1 A beneficiation method for enriching and recovering lithium from weathered clay-type lithium ore, specifically including the following steps:

[0032] S1. The weathered clay lithium ore is crushed to -2mm using a jaw crusher and a double roller mill.

[0033] S2. Add water to the crushed ore to make a slurry with an ore mass concentration of 25%, and place it in a mixing tank. Stir at 600 rpm and soak and stir for 30 minutes.

[0034] S3. The stirred slurry is deslimed for the first time, and the desliming particle size is 0.020mm to obtain fine mud 1 and sediment 1.

[0035] S4. The sediment 1 is treated with ultrasound for 30 minutes and deslimed twice. The deslimed particle size is 0.020 mm, and fine mud 2 and sediment 2 are obtained.

[0036] S5. Combine fine mud 1 and fine mud 2 and deslim again to obtain fine mud 3 and sediment 3. The desliming particle size is 0.010mm.

[0037] S6. The sediment 3 is subjected to reverse flotation for impurity removal, and three cleaning processes are carried out by combining one roughing and one scavenging froth. The cleaned froth is the reverse flotation tailings, and the other products are lithium flotation concentrate. The reverse flotation modifier is sodium carbonate, with a dosage of 400 g / t; the depressant is water glass, with a dosage of 1200 g / t; and the collector is sodium fatty acid, with a dosage of 800 g / t.

[0038] Fine mud 3 and lithium flotation concentrate are used as lithium concentrate products.

[0039] The formula for calculating the recovery rate is as follows:

[0040]

[0041] Wherein, ε represents the Li2O recovery rate of the concentrate; a, b, and c represent the Li2O grade of the raw ore, concentrate, and tailings, respectively.

[0042] Using the above process, a comprehensive lithium concentrate with a Li2O content of 0.71% and a recovery rate of 71.75% can be obtained from weathered lithium clay ore in a certain area of ​​Guizhou Province, where the raw ore contains 0.54% Li2O.

[0043] Example 2

[0044] Reference Figure 1 A beneficiation method for enriching and recovering lithium from weathered clay-type lithium ore, specifically including the following steps:

[0045] S1. The weathered clay lithium ore is crushed to -2mm using a jaw crusher and a double roller mill.

[0046] S2. Add water to the crushed ore to make a slurry with an ore mass concentration of 25%, and place it in a mixing tank. Stir at 1200 rpm and soak and stir for 60 minutes.

[0047] S3. The stirred slurry is deslimed for the first time, and the desliming particle size is 0.025mm to obtain fine mud 1 and sediment 1.

[0048] S4. The sediment 1 is treated with ultrasound for 30 minutes and deslimed twice. The deslimed particle size is 0.025mm, and fine mud 2 and sediment 2 are obtained.

[0049] S5. Combine fine mud 1 and fine mud 2 for desliming again, with a desliming particle size of 0.010 mm, to obtain fine mud 3 and sediment 3.

[0050] S6. The sediment 3 is subjected to reverse flotation for impurity removal, and three cleaning processes are carried out by combining one roughing and one scavenging froth. The cleaned froth is the reverse flotation tailings, and the other products are lithium flotation concentrate. The reverse flotation modifier is sodium carbonate, with a dosage of 400 g / t; the depressant is water glass, with a dosage of 1000 g / t; and the collector is sodium fatty acid, with a dosage of 600 g / t.

[0051] The fine mud 3 and lithium flotation concentrate are used as lithium concentrate products.

[0052] Using the above process, a comprehensive lithium concentrate with a Li2O content of 0.72% and a recovery rate of 72.35% can be obtained from weathered lithium clay ore in a certain area of ​​Guizhou Province, where the raw ore contains 0.53% Li2O.

[0053] Example 3

[0054] Reference Figure 1 A beneficiation method for enriching and recovering lithium from weathered clay-type lithium ore, specifically including the following steps:

[0055] S1. The weathered clay lithium ore is crushed to -2mm using a jaw crusher and a double roller mill.

[0056] S2. Add water to the crushed ore to make a slurry with an ore mass concentration of 30%, and place it in a mixing tank. Stir at 800 rpm and soak and stir for 30 minutes.

[0057] S3. The stirred slurry is deslimed for the first time, and the desliming particle size is 0.025mm to obtain fine mud 1 and sediment 1.

[0058] S4. The sediment 1 is treated with ultrasound for 40 minutes and deslimed twice. The deslimed particle size is 0.025 mm, and fine mud 2 and sediment 2 are obtained.

[0059] S5. Combine fine mud 1 and fine mud 2 for desliming again, with a desliming particle size of 0.010 mm, to obtain fine mud 3 and sediment 3.

[0060] S6. The sediment 3 is subjected to reverse flotation for impurity removal, and three cleaning processes are carried out by combining one roughing and one scavenging froth. The cleaned froth is the reverse flotation tailings, and the other products are lithium flotation concentrate. The reverse flotation modifier is sodium carbonate, with a dosage of 300 g / t; the depressant is water glass, with a dosage of 800 g / t; and the collector is sodium fatty acid, with a dosage of 600 g / t.

[0061] Fine mud 3 and lithium flotation concentrate are used as lithium concentrate products.

[0062] Using the above process, a comprehensive lithium concentrate with a Li2O content of 0.72% and a recovery rate of 76.25% can be obtained from weathered lithium clay ore in a certain area of ​​Guizhou Province, where the raw ore contains 0.55% Li2O.

[0063] Example 4

[0064] Reference Figure 1 A beneficiation method for enriching and recovering lithium from weathered clay-type lithium ore, specifically including the following steps:

[0065] S1. The weathered clay lithium ore is crushed to -2mm using a jaw crusher and a double roller mill.

[0066] S2. Add water to the crushed ore to make a slurry with an ore mass concentration of 30%, and place it in a mixing tank. Stir at 600 rpm and soak and stir for 40 minutes.

[0067] S3. The stirred slurry is deslimed for the first time, and the desliming particle size is 0.020mm to obtain fine mud 1 and sediment 1.

[0068] S4. The sediment 1 is treated with ultrasound for 40 minutes and deslimed twice. The deslimed particle size is 0.020 mm, and fine mud 2 and sediment 2 are obtained.

[0069] S5. Combine fine mud 1 and fine mud 2 for desliming again, with a desliming particle size of 0.010 mm, to obtain fine mud 3 and sediment 3.

[0070] S6. The sediment 3 is subjected to reverse flotation for impurity removal, and three cleaning processes are carried out by combining one roughing and one scavenging froth. The cleaned froth is the reverse flotation tailings, and the other products are lithium flotation concentrate. The reverse flotation modifier is sodium carbonate, with a dosage of 300 g / t; the depressant is water glass, with a dosage of 600 g / t; and the collector is sodium fatty acid, with a dosage of 600 g / t.

[0071] Fine mud 3 and lithium flotation concentrate are used as lithium concentrate products.

[0072] Using the above process, a comprehensive lithium concentrate with a Li2O content of 0.74% and a recovery rate of 79.39% can be obtained from weathered lithium clay ore in a certain area of ​​Guizhou Province, where the raw ore contains 0.55% Li2O.

[0073] Example 5

[0074] Reference Figure 1 A beneficiation method for enriching and recovering lithium from weathered clay-type lithium ore, specifically including the following steps:

[0075] S1. The weathered clay lithium ore is crushed to -2mm using a jaw crusher and a double roller mill.

[0076] S2. Add water to the crushed ore to make a slurry with an ore mass concentration of 25%, and place it in a mixing tank. Stir at 600 rpm and soak and stir for 40 minutes.

[0077] S3. The stirred slurry is deslimed for the first time, and the desliming particle size is 0.020mm to obtain fine mud 1 and sediment 1.

[0078] S4. The sediment 1 is treated with ultrasound for 40 minutes and deslimed twice. The deslimed particle size is 0.020 mm, and fine mud 2 and sediment 2 are obtained.

[0079] S5. Combine fine mud 1 and fine mud 2 for desliming again, with a desliming particle size of 0.010 mm, to obtain fine mud 3 and sediment 3.

[0080] S6. The sediment 3 is subjected to reverse flotation for impurity removal, and three cleaning processes are carried out by combining one roughing and one scavenging froth. The cleaned froth is the reverse flotation tailings, and the other products are lithium flotation concentrate. The reverse flotation modifier is sodium carbonate, with a dosage of 400 g / t; the depressant is water glass, with a dosage of 600 g / t; and the collector is sodium fatty acid, with a dosage of 800 g / t.

[0081] Fine mud 3 and lithium flotation concentrate are used as lithium concentrate products.

[0082] Using the above process, a comprehensive lithium concentrate with a Li2O content of 0.78% and a recovery rate of 70.28% can be obtained from weathered lithium clay ore in a certain area of ​​Guizhou Province, where the raw ore contains 0.56% Li2O.

[0083] Comparative Example 1

[0084] A method for enriching lithium, the specific process is as follows:

[0085] S1. Crush the weathered clay-type lithium ore to -2mm, wet ball mill for 5 minutes, until the content of -0.045mm is above 90%;

[0086] S2. After grinding, adjust the product slurry to an ore mass concentration of 30% and use reverse flotation to remove impurities with one rougher and one scavenger. In the rougher, add 2000g / t of sodium carbonate, 2000g / t of water glass, and 1000g / t of sodium fatty acid in sequence. In the scavenger, add 400g / t of sodium fatty acid. Combine the froth from the rougher and scavenger.

[0087] S3, merge the bubble blank selection 3 times, and merge the selected tailings.

[0088] The selected tailings and scavenged tailings are combined into a comprehensive lithium concentrate.

[0089] Using the above process, a comprehensive lithium concentrate with a Li2O content of 0.57% and a recovery rate of 84.58% can be obtained from weathered lithium clay ore in a certain area of ​​Guizhou, where the raw ore contains 0.55% Li2O. However, this method is not effective in improving the Li2O grade of lithium concentrate from weathered lithium clay ore, and the use of grinding processes and high-dosage beneficiation reagents increases beneficiation costs.

[0090] The above description of the embodiments is only for the purpose of helping to understand the technical solution and core idea of ​​the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A beneficiation method for enriching and recovering lithium from weathered clay-type lithium ore, characterized in that, Includes the following steps: S1. Crush the weathered clay-type lithium ore to less than 2mm; S2. Add water to the ore crushed in step S1 to make a slurry with an ore mass concentration of 25% to 30%, and place it in a mixing container. Soak and stir it thoroughly. The stirring and soaking conditions are: stirring speed of 600 to 1200 rpm and stirring and soaking time of 30 to 60 minutes. S3. The slurry after stirring in step S2 is deslimed for the first time to obtain fine mud 1 and sediment 1. The particle size of fine mud 1 is controlled at 0.020~0.025mm. S4. The sand 1 obtained in step S3 is treated with ultrasound to deslim it twice, and fine mud 2 and sand 2 are obtained. The particle size of fine mud 2 is controlled at 0.020~0.025mm. S5. Combine the fine mud 1 obtained in step S3 with the fine mud 2 obtained in step S4 and deslim again to obtain fine mud 3 and sediment 3. The particle size of fine mud 3 is less than 0.010 mm. S6. The sediment obtained in step S5 is subjected to reverse flotation to remove impurities, and lithium flotation concentrate is obtained. The reverse flotation adopts a three-stage cleaning process with one roughing and one scavenging froth combined. The cleaned froth is the reverse flotation tailings, and the other products are lithium flotation concentrate. The dosage of reverse flotation reagents is relative to the dosage of weathered clay-type lithium ore in step S1. The reverse flotation modifier is sodium carbonate, with a total dosage of 300-400 g / t. The depressant is water glass, with a total dosage of 600-1200 g / t. The collector is fatty acid soap, with a total dosage of 600-800 g / t. The roughing and scavenging process refers to adding sodium carbonate, water glass and fatty acid soap to sediment 3 in sequence for roughing. The material after roughing is then scavenged with fatty acid soap.

2. The mineral processing method according to claim 1, characterized in that, The weathered clay-type lithium ore mentioned in step S1 is a surface weathered ore with a Li2O content of 0.5% to 0.6%.

3. The mineral processing method according to claim 1 or 2, characterized in that, The ultrasonic treatment time in step S4 is 30 to 40 minutes.

4. The mineral processing method according to claim 1, characterized in that, The fine mud 3 and lithium flotation concentrate are used as lithium concentrate products.

5. The mineral processing method according to claim 1, characterized in that, The inhibitor mentioned in step S6 is water glass, with a dosage of 600-1000 g / t.

6. The mineral processing method according to claim 1, characterized in that, The collector mentioned in step S6 is sodium fatty acid.

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