Beneficiation method of low-grade spodumene

Abstract

The application provides a beneficiation method of low-grade spodumene, which comprises the following steps: wet grinding of the to-be-beneficiated raw ore to obtain a first ore slurry, then adding water to the first ore slurry and stirring to obtain a to-be-beneficiated ore slurry with a preset concentration; adding a first preset reagent to the obtained to-be-beneficiated ore slurry to perform slime reverse flotation to obtain slime and desliming tailings; adding a second preset reagent to the desliming tailings to perform desliming tailings direct flotation to obtain lithium concentrate and tailings; the second preset reagent comprises an adjusting agent, a composite depressant and a composite collector; the composite depressant is obtained by compounding tannic acid, hydroxyl citric acid, lactic acid and sodium lignosulfonate; and the composite collector is obtained by compounding oleic acid, tall oil, naphthenic acid and white oil. The beneficiation method of low-grade spodumene is characterized in that the beneficiation process of desliming by reverse flotation and direct flotation of spodumene is used to separate a large amount of gangue minerals; then, under the joint action of the composite depressant and the composite collector, the low-grade spodumene is effectively recovered, and the resource utilization rate is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of spodumene beneficiation, and particularly relates to a beneficiation method of low-grade spodumene. BACKGROUND

[0002] Lithium has been widely used in metallurgy, aviation, aerospace and other fields, especially in lithium batteries and controllable thermonuclear fusion reactors. In nature, lithium minerals mainly exist in the form of spodumene, lepidolite and variscite. Spodumene, as a raw material for lithium chemicals, is widely used in lithium chemical industry, glass and ceramic industry, and is known as 'industrial monosodium glutamate'.

[0003] However, the spodumene ore generally contains mica, kaolin and other easy argillization minerals, resulting in high content of gangue minerals. In the grinding and crushing process, the argillization is easy to produce a large amount of difficult-to-wash slurry, which deteriorates the flotation environment and affects the floatability of spodumene. The existence of a large amount of slurry in the spodumene flotation system mainly affects the flotation in the following aspects: the viscosity of the slurry increases, the dispersion between mineral particles becomes poor; the slurry adsorbs a large amount of reagents, resulting in high reagent consumption; the slurry forms a cover on the surface of spodumene minerals, hindering the action of reagents.

[0004] In order to eliminate the influence of slurry, the existing beneficiation methods of spodumene ore are generally divided into two kinds. One is to reduce the generation of secondary slurry in the crushing process, and to remove part of the waste by gravity separation. The particle size of the waste removed by gravity separation is generally 0.5-6mm, and the Li2O grade is 0.2%-0.3%. This method will cause part of the spodumene which is not dissociated and has good selectivity to be directly removed, resulting in resource waste. The other is to use the process of strong stirring by alkali method, that is, to add a large amount of Na2CO3 and NaOH to the slurry and stir for a long time to disperse the slurry and reduce the influence of gangue slurry. This method has high reagent consumption and is suitable for ores with low content of slurry and easy-to-float gangue.

[0005] For low-grade spodumene ore, due to the low content of useful substances, the Li2O content is only 0.4%-0.6%. The beneficiation effect is poor by using the above two methods, and the Li2O recovery rate is low. Generally speaking, the beneficiation recovery rate of low-grade spodumene ore (Li2O grade of 0.3-0.6%) is less than 65%. It can be seen that the beneficiation of low-grade spodumene will cause waste of lithium resources. With the development of new energy and the in-depth development of lithium resources, strengthening the recovery and utilization of low-grade spodumene ore is one of the research hotspots in recent years.

[0006] Therefore, it is necessary to design an improved beneficiation method of low-grade spodumene to solve the above problems. SUMMARY

[0007] The application aims to provide a beneficiation method of low-grade spodumene, which separates a large amount of gangue minerals such as mica, feldspar and kaolin from the source, minimizes the influence of the gangue minerals on beneficiation, and then reduces the influence of the gangue minerals on spodumene under the action of a composite inhibitor, realizes effective collection of spodumene by a composite collector, and finally realizes effective recovery of low-grade spodumene under the joint action of the composite inhibitor and the composite collector, thereby improving resource utilization.

[0008] To achieve the above-mentioned application purposes, the application provides a beneficiation method of low-grade spodumene, which is characterized by comprising the following steps:

[0009] S1. Wet grinding of the raw ore to be selected to obtain a first ore slurry, and then adding water to the first ore slurry to obtain a preselected concentration of the ore slurry to be selected;

[0010] S2. Adding a first preselected reagent to the ore slurry to be selected in step S1 to perform slime reverse flotation to obtain slime and desliming tailings;

[0011] S3. Adding a second preselected reagent to the desliming tailings in step S2 to perform desliming tailings direct flotation to obtain lithium concentrate and tailings; the second preselected reagent comprises an adjusting agent, a composite inhibitor and a composite collector; the adjusting agent is sodium carbonate; the composite inhibitor is obtained by compounding tannic acid, hydroxyl citric acid, lactic acid and sodium lignosulfonate; and the composite collector is obtained by compounding oleic acid, tall oil, naphthenic acid and white oil.

[0012] As a further improvement of the application, in step S3, the mass percentage of oleic acid, tall oil, naphthenic acid and white oil in the composite collector is (20%-30%):(10%-20%):(30%-40%):(30%-40%).

[0013] As a further improvement of the application, in step S3, the mass percentage of tannic acid, hydroxyl citric acid, lactic acid and sodium lignosulfonate in the composite inhibitor is (20%-30%):(30%-40%):(20%-30%):(10%-20%).

[0014] As a further improvement of the application, in step S1, in the first ore slurry, the mass percentage of the ore powder with a particle size less than 0.074 mm in the raw ore to be selected is 70%-75%; and the mass concentration of the ore slurry to be selected is 30%-35%.

[0015] As a further improvement of the application, in step S3, the desliming tailings direct flotation process comprises once roughing, three times of cleaning and twice scavenging, and finally the lithium concentrate and the tailings are obtained.

[0016] As a further improvement of the present application, the second preset reagent comprises: 1000-3000 g / t of a regulator, 500-1500 g / t of a composite depressant and 400-1000 g / t of a composite collector as roughing reagents; 100-300 g / t of a regulator and 10-100 g / t of a composite collector as first-stage cleaning reagents, 50-150 g / t of a regulator and 10-50 g / t of a composite collector as second-stage cleaning reagents; 200-300 g / t of a composite collector as first-stage scavenging reagents, and 100-200 g / t of a composite collector as second-stage scavenging reagents.

[0017] As a further improvement of the present application, in step S2, the slime reverse flotation process comprises one roughing.

[0018] As a further improvement of the present application, the first preset reagent is 20-40 g / t of cocoyl amine as a roughing reagent.

[0019] As a further improvement of the present application, the stirring time for adding the regulator is 2-3 min; the stirring time for adding the composite depressant is 2-3 min; and the stirring time for adding the composite collector is 2-3 min.

[0020] As a further improvement of the present application, in step S3, the obtained lithium concentrate contains up to 4.68% of Li2O, and the recovery rate is as high as 66.49%.

[0021] The present application has the following beneficial effects:

[0022] (1) The beneficiation method for low-grade spodumene provided by the present application, according to the characteristics of high content of gangue minerals in low-grade spodumene, first performs a slime reverse flotation operation, separates a large amount of mica, feldspar and kaolin and other gangue minerals from the source, and maximally reduces the influence of gangue minerals on beneficiation. Then, the desliming tailings are subjected to positive flotation, through reasonable compounding, setting of a composite depressant and a composite collector, under the action of the composite depressant, the influence of gangue minerals on spodumene is reduced, and at the same time, the composite collector realizes effective collection of spodumene. Finally, under the joint action of the composite depressant and the composite collector, effective recovery of low-grade spodumene is realized, and the resource utilization rate is improved.

[0023] (2) The beneficiation method of low-grade spodumene provided by the application has less lithium loss in the way of reverse flotation desliming compared with the existing physical desliming process, and fundamentally improves the lithium recovery rate; compared with the traditional high-alkali strong stirring slurry cleaning process, the process is simple, the equipment requirement is low, and the pulp alkalinity is low; the traditional depressant has poor inhibitory effect on the mesoperidotite mineral of low-grade spodumene, and it is difficult to effectively inhibit impurities, and the composite depressant of the application strengthens the inhibition of impurities and improves the recovery rate; the traditional collector has weak collection effect on low-grade spodumene, and the composite collector of the application strengthens the collection of spodumene and further improves the recovery rate. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The process flow chart of the beneficiation method of low-grade spodumene of the application. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the application more clear, the application will be described in detail below with reference to the drawings and specific embodiments.

[0026] Here, it also needs to be explained that, in order to avoid the unnecessary details from obscuring the application, only the structures and / or processing steps closely related to the scheme of the application are shown in the drawings, and other details not closely related to the application are omitted.

[0027] In addition, it also needs to be explained that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment.

[0028] Please refer to Figure 1 The application provides a beneficiation method of low-grade spodumene, which comprises the following steps:

[0029] S1. Slurry preparation:

[0030] The raw ore to be selected is wet ground to obtain a first slurry, and then water is added to the first slurry for stirring to obtain a to-be-selected slurry with a mass concentration of 30% to 35%.

[0031] In the first slurry, the mineral powder with a particle size of less than 0.074 mm accounts for 70% to 75% of the mass of the raw ore to be selected, and the control of the mineral powder in the slurry to a certain fineness is more conducive to the separation and purification of each substance in the mineral powder and improves the recovery rate.

[0032] S2. Slime reverse flotation:

[0033] The first preset reagent is added to the prepared ore slurry in step S1 to perform slime reverse flotation, to obtain slime and desliming tailings, the slime is directly discarded, and the desliming tailings continue to be subjected to subsequent mineral processing. The first preset reagent is 20-40 g / t of cocamine as a roughing reagent. As a cationic collector, cocamine can better foam float silicate gangue slime such as mica, feldspar and kaolin.

[0034] The slime reverse flotation process includes one roughing, and the specific operation is as follows: the ore slurry is subjected to roughing to obtain slime and desliming tailings.

[0035] S3. Lithium concentrate positive flotation:

[0036] The second preset reagent is added to the desliming tailings obtained in step S2 to perform desliming tailings positive flotation, to obtain lithium concentrate and tailings. The second preset reagent includes adjusting agent, composite depressant and composite collector; specifically, the adjusting agent is sodium carbonate; the composite depressant is obtained by compounding tannic acid, hydroxyl citric acid, lactic acid and sodium lignosulfonate, and the mass percentage of tannic acid, hydroxyl citric acid, lactic acid and sodium lignosulfonate is (20%-30%):(30%-40%):(20%-30%):(10%-20%); the composite collector is obtained by compounding oleic acid, tall oil, naphthenic acid and white oil, and the mass percentage of oleic acid, tall oil, naphthenic acid and white oil is (20%-30%):(10%-20%):(30%-40%):(30%-40%).

[0037] The second preset reagent includes: 1000-3000 g / t of adjusting agent, 500-1500 g / t of composite depressant and 400-1000 g / t of composite collector as roughing reagents; 100-300 g / t of adjusting agent and 10-100 g / t of composite collector as first-time cleaning reagents, 50-150 g / t of adjusting agent and 10-50 g / t of composite collector as second-time cleaning reagents; 200-300 g / t of composite collector as first-time scavenging reagent, and 100-200 g / t of composite collector as second-time scavenging reagent.

[0038] In the roughing, cleaning and scavenging processes, the stirring time of the adjusting agent is 2-3 min; the stirring time of the composite depressant is 2-3 min; and the stirring time of the composite collector is 2-3 min.

[0039] The lithium concentrate positive flotation process includes one roughing, three cleanings and two scavengings, to finally obtain lithium concentrate and tailings; specifically including the following steps:

[0040] S31. The desliming tailings obtained in step S2 are subjected to lithium concentrate roughing to obtain lithium roughing concentrate and lithium roughing tailings;

[0041] S32. The lithium roughing concentrate obtained in step S31 is subjected to first cleaning to obtain a lithium cleaning first concentrate and a lithium cleaning first tailing; wherein the lithium cleaning first tailing returns to the lithium roughing step of step S31;

[0042] S33. The lithium cleaning first concentrate obtained in step S32 is subjected to second cleaning to obtain a lithium cleaning second concentrate and a lithium cleaning second tailing; wherein the lithium cleaning second tailing returns to the first cleaning step of step S32;

[0043] S34. The lithium cleaning second concentrate obtained in step S33 is subjected to third cleaning to obtain a lithium concentrate and a lithium cleaning third tailing; wherein the lithium cleaning third tailing returns to the second cleaning step of step S33;

[0044] S35. The lithium roughing tailing obtained in step S31 is subjected to first scavenging to obtain a lithium scavenging first concentrate and a lithium scavenging first tailing; wherein the lithium scavenging first concentrate returns to the lithium roughing step of step S31;

[0045] S36. The lithium scavenging first tailing obtained in step S35 is subjected to second scavenging to obtain a lithium scavenging second concentrate and a tailing; wherein the lithium scavenging second concentrate returns to the first scavenging step of step S35, and the tailing and the slime obtained in step S2 are discarded together.

[0046] In step S3, the lithium concentrate obtained contains as high as 4.68% Li2O, and the recovery rate is as high as 66.49%.

[0047] The present application is described below through specific examples:

[0048] Example 1

[0049] The content of spodumene in the selected raw ore used in this example is 6.9% (Li2O content is 0.45%) by mass percentage, the content of mica is 5.8%, the content of feldspar is 24.5%, the content of kaolin is 2.6%, and the content of quartz is 56.4%.

[0050] The present application provides a beneficiation method for low-grade spodumene, which comprises the following steps:

[0051] S1. Slurry preparation:

[0052] The selected raw ore is wet ground to obtain a first slurry, and then water is added to the first slurry and stirred to obtain a selected slurry with a mass concentration of 33%.

[0053] In the first slurry, the content of ore powder with a particle size of less than 0.074 mm is 73% of the mass of the selected raw ore.

[0054] S2. Slime reverse flotation:

[0055] The first preset reagent is added to the prepared ore slurry in step S1 to perform slime reverse flotation, to obtain slime and desliming tailings, the slime is directly discarded, and the desliming tailings continue to be subjected to subsequent mineral processing. The first preset reagent is 30 g / t of cocoyl amine as a roughing reagent.

[0056] The slime reverse flotation process includes one roughing, and the specific operation is as follows: the ore slurry is subjected to roughing to obtain slime and desliming tailings.

[0057] S3. Lithium concentrate positive flotation:

[0058] The second preset reagent is added to the desliming tailings obtained in step S2 to perform desliming tailings positive flotation, to obtain lithium concentrate and tailings. The second preset reagent includes an adjusting agent, a composite inhibitor and a composite collector; specifically, the adjusting agent is sodium carbonate; the composite inhibitor is obtained by compounding tannic acid, hydroxyl citric acid, lactic acid and sodium lignosulfonate, and the mass percentage of tannic acid, hydroxyl citric acid, lactic acid and sodium lignosulfonate is 25%:35%:25%:15%; the composite collector is obtained by compounding oleic acid, tall oil, naphthenic acid and white oil, and the mass percentage of oleic acid, tall oil, naphthenic acid and white oil in the composite collector is 25%:15%:30%:30%.

[0059] The lithium concentrate positive flotation process includes one roughing, three times of cleaning and two times of scavenging, to finally obtain lithium concentrate and tailings; and the specific operation includes the following steps:

[0060] S31. The desliming tailings obtained in step S2 are added with 2000 g / t of sodium carbonate and stirred for 3 min, then added with 1000 g / t of the composite inhibitor and stirred for 3 min, and finally added with 600 g / t of the composite collector and stirred for 3 min, to perform lithium concentrate roughing, to obtain lithium roughing concentrate and lithium roughing tailings;

[0061] S32. The lithium roughing concentrate obtained in step S31 is added with 200 g / t of sodium carbonate and stirred for 3 min, then added with 30 g / t of the composite collector and stirred for 3 min, to perform first cleaning, to obtain lithium cleaning first concentrate and lithium cleaning first tailings; wherein the lithium cleaning first tailings are returned to the lithium roughing step in step S31;

[0062] S33. The lithium cleaning first concentrate obtained in step S32 is added with 100 g / t of sodium carbonate and stirred for 3 min, then added with 15 g / t of the composite collector and stirred for 3 min, to perform second cleaning, to obtain lithium cleaning second concentrate and lithium cleaning second tailings; wherein the lithium cleaning second tailings are returned to the first cleaning step in step S32;

[0063] S34. The lithium concentrate obtained in step S33 is subjected to a third cleaning (without adding reagents) to obtain a lithium concentrate and a lithium cleaning third tailing; wherein the lithium cleaning third tailing returns to the second cleaning step of step S33;

[0064] S35. The lithium roughing tailing obtained in step S31 is added with 250 g / t of the composite collector and stirred for 3 min to perform a first scavenging to obtain a lithium scavenging first concentrate and a lithium scavenging first tailing; wherein the lithium scavenging first concentrate returns to the lithium roughing step of step S31.

[0065] S36. The lithium scavenging first tailing obtained in step S35 is added with 150 g / t of the composite collector and stirred for 3 min to perform a second scavenging to obtain a lithium scavenging second concentrate and a tailing; wherein the lithium scavenging second concentrate returns to the first scavenging step of step S35, and the tailing and the slime obtained in step S2 are discarded together.

[0066] The lithium concentrate obtained has a Li2O content of 4.68% and a recovery rate of 66.49%.

[0067] Examples 2-4 and Comparative Examples 1-5

[0068] A beneficiation method of low-grade spodumene, which is different from Example 1 in that in step S3, the proportions of the substances in the composite depressant are different, and the others are substantially the same as those in Example 1, which will not be repeated here.

[0069] Table 1 Lithium content and recovery rate of lithium concentrate obtained in Examples 1-4 and Comparative Examples 1-5

[0070] Example Proportion of each substance in the composite depressant Li2O (%) Recovery rate (%) Example 1 25％:35％:25％:15％ 4.68 66.49 Example 2 30％:40％:20％:10％ 4.71 66.42 Example 3 20％:30％:30％:20％ 4.74 66.34 Example 4 30％:30％:20％:20％ 4.84 66.30 Comparative Example 1 60％:0:25％:15％ 4.59 61.81 Comparative Example 2 25％:35％:0:40％ 4.51 61.90 Comparative Example 3 0:60％:25％:15％ 4.58 61.73 Comparative Example 4 25％:35％:40％:0 4.52 61.85 Comparative Example 5 10％:50％:15％:25％ 4.87 64.15

[0071] As can be seen from Table 1, with the change of the content of each substance in the composite depressant, the lithium content and recovery rate of the obtained lithium concentrate change, but the overall recovery rate is high.

[0072] However, when any component is missing in the composite depressant or the proportions of the substances in the composite depressant are not appropriate, the lithium content and recovery rate of the obtained lithium concentrate are significantly reduced. Therefore, only when the four substances of tannic acid, hydroxycitric acid, lactic acid and sodium lignosulfonate are compounded in appropriate proportions, can they play a good inhibitory effect.

[0073] Examples 5-6 and Comparative Examples 6-10

[0074] A beneficiation method of low-grade spodumene, which is different from Example 1 in that in step S3, the proportions of the substances in the composite depressant are different, and the others are substantially the same as those in Example 1, which will not be repeated here.

[0075] Li content and recovery rate of lithium concentrate obtained from examples 5-6 and comparative examples 6-10

[0076] Example Proportion of each substance in the composite depressant Li2O (%) Recovery rate (%) Example 1 25％:15％:30％:30％ 4.68 66.49 Example 5 20％:10％:30％:40％ 4.72 66.47 Example 6 30％:10％:30％:30％ 4.63 66.58 Comparative Example 6 25％:15％:60％:0 4.52 61.74 Comparative Example 7 25％:15％:0:60％ 4.58 61.39 Comparative Example 8 45％:0:30％:30％ 4.48 61.84 Comparative Example 9 0:45％:30％:30％ 4.46 61.93 Comparative Example 10 15％:8％:25％:52％ 4.61 61.97

[0077] As can be seen from Table 2, with the change of the content of each substance in the composite collector, the Li content and recovery rate of the obtained lithium concentrate change, but the overall recovery rate is still high.

[0078] However, when any component is missing in the composite collector or the proportion of each substance in the composite collector is not appropriate, the Li content and recovery rate of the obtained lithium concentrate are significantly reduced. This shows that only when the four substances of oleic acid, tar oil, naphthenic acid and white oil are compounded in appropriate proportions, can a good collecting effect be achieved.

[0079] Example 7

[0080] A beneficiation method of low-grade spodumene, compared with example 1, the difference is that in step S31, the addition amount of sodium carbonate is 3000g / t, and the others are substantially the same as example 1, which will not be repeated here. The Li2O content of the lithium concentrate obtained in example 7 is 4.83%, and the recovery rate is 66.08%.

[0081] Example 8

[0082] A beneficiation method of low-grade spodumene, compared with example 1, the difference is that in step S31, the addition amount of composite depressant is 1500g / t, and the others are substantially the same as example 1, which will not be repeated here. The Li2O content of the lithium concentrate obtained in example 8 is 4.98%, and the recovery rate is 65.72%. It can be seen that with the increase of the addition amount of the composite depressant, the Li2O content in the lithium concentrate increases.

[0083] Example 9

[0084] A beneficiation method of low-grade spodumene, compared with example 1, the difference is that in step S31, the addition amount of composite collector is 800g / t, and the others are substantially the same as example 1, which will not be repeated here. The Li2O content of the lithium concentrate obtained in example 9 is 4.31%, and the recovery rate is 67.42%.

[0085] Comparative example 11

[0086] A beneficiation method of low-grade spodumene, compared with example 1, the difference lies in that the collector is traditional collector oxidized paraffin soap + naphthenic acid soap, specifically, in step S31, the dosage of oxidized paraffin soap + naphthenic acid soap is 300+300g / t; in step S32, the dosage of oxidized paraffin soap + naphthenic acid soap is 15+15g / t; in step S33, the dosage of oxidized paraffin soap + naphthenic acid soap is 7.5+7.5g / t; in step S35, the dosage of oxidized paraffin soap + naphthenic acid soap is 150+150g / t; in step S36, the dosage of oxidized paraffin soap + naphthenic acid soap is 75+75g / t; other than example 1, which is not described here. The lithium concentrate obtained in Comparative Example 11 contains 4.27% Li2O, and the recovery rate is 61.61%. Therefore, when the composite collector of the application is not used, the lithium content and recovery rate of the lithium concentrate are lower than those of example 1, further illustrating the high collection effect of the composite collector of the application; at the same time, it illustrates the mutual cooperation between the composite collector and the composite depressor of the application.

[0087] Comparative Example 12

[0088] A beneficiation method of low-grade spodumene, compared with example 1, the difference lies in that in step S3, the depressant is traditional depressant sodium fluoride, other than example 1, which is not described here. The lithium concentrate obtained in Comparative Example 12 contains 4.16% Li2O, and the recovery rate is 61.42%. Therefore, it further illustrates the mutual cooperation between the composite collector and the composite depressor of the application.

[0089] Comparative Example 13

[0090] A beneficiation method of low-grade spodumene, compared with example 1, the difference lies in that, without the reverse flotation desliming step of step S2, directly carrying out spodumene flotation, other than example 1, which is not described here. The lithium concentrate obtained in Comparative Example 13 contains 4.13% Li2O, and the recovery rate is 61.85%, which shows that without pre-desliming, gangue minerals will seriously affect the flotation of lithium concentrate.

[0091] Comparative Example 14

[0092] A beneficiation method of low-grade spodumene, compared with example 1, the difference lies in that, in the process of step S3, no composite depressant is added, other than example 1, which is not described here. The lithium concentrate obtained in Comparative Example 14 contains 4.31% Li2O, and the recovery rate is 61.08%.

[0093] Comparative Example 15

[0094] A beneficiation method of low-grade spodumene, compared with example 1, a traditional high-alkali process is used, that is, sodium hydroxide is used for strong stirring and slurry, the composite depressant in example 1 is replaced with sodium hydroxide and stirred for 30 min, and the others are substantially the same as in example 1, which will not be repeated here. The lithium concentrate obtained in Comparative Example 15 contains 4.25% Li2O, and the recovery rate is 62.03%.

[0095] Comparative Example 16

[0096] A beneficiation method of low-grade spodumene, compared with example 1, the difference is that step S2 uses a traditional desliming process, specifically using a hydrocyclone to remove -20 μm size fraction fine mud, and the spodumene flotation process is substantially the same as in example 1, which will not be repeated here. The desliming product obtained in Comparative Example 16 contains 0.76% Li2O, and the recovery rate is 10.24%, and the final lithium concentrate contains 4.82% Li2O, and the recovery rate is 58.92%.

[0097] In summary, the beneficiation method of low-grade spodumene provided by the present application, through the process flow of reverse flotation desliming-positive flotation to recover spodumene, separates a large amount of mica, feldspar and kaolin and other gangue minerals from the source, minimizing the impact of gangue minerals on beneficiation; then, under the action of the composite depressant, the impact of gangue minerals on spodumene is reduced, and the composite collector realizes effective collection of spodumene, finally, under the joint action of the composite depressant and the composite collector, effective recovery of low-grade spodumene is realized, and the resource utilization rate is improved.

[0098] The above examples are only used to illustrate the technical solutions of the present application and not to limit it, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A method for beneficiating low-grade spodumene, characterized in that, Includes the following steps: S1. The raw ore to be selected is wet-milled to obtain a first slurry. Then, water is added to the first slurry and stirred to obtain a slurry of the selected ore with a preset concentration. S2. Add the first preset reagent to the slurry to be selected in step S1 to perform reverse flotation of ore slime, and obtain ore slime and desliming tailings; S3. Add a second preset reagent to the deslimed tailings from step S2 to perform positive flotation of the deslimed tailings to obtain lithium concentrate and tailings; the second preset reagent includes a modifier, a composite inhibitor, and a composite collector; the modifier is sodium carbonate; the composite inhibitor is a compound of tannic acid, hydroxycitric acid, lactic acid, and sodium lignosulfonate, wherein the mass percentages of tannic acid, hydroxycitric acid, lactic acid, and sodium lignosulfonate in the composite inhibitor are (20%-30%):(30%-40%):(20%-30%):(10%-20%); the composite collector is a compound of oleic acid, talc oil, naphthenic acid, and white oil, wherein the mass percentages of oleic acid, talc oil, naphthenic acid, and white oil in the composite collector are (20%-30%):(10%-20%):(30%-40%):(30%-40%).

2. The beneficiation method for low-grade spodumene according to claim 1, characterized in that, In step S1, in the first slurry, mineral powder with a particle size of less than 0.074 mm accounts for 70% to 75% of the mass of the raw ore to be selected; the mass concentration of the slurry to be selected is 30% to 35%.

3. The beneficiation method for low-grade spodumene according to claim 1, characterized in that, In step S3, the desliming tailings positive flotation process includes one roughing, three cleaning and two scavenging processes, ultimately obtaining the lithium concentrate and the tailings.

4. The beneficiation method for low-grade spodumene according to claim 3, characterized in that, The second preset reagent includes: 1000-3000 g / t of modifier, 500-1500 g / t of compound inhibitor and 400-1000 g / t of compound collector as roughing reagent; 100-300 g / t of modifier and 10-100 g / t of compound collector as first cleaning reagent; 50-150 g / t of modifier and 10-50 g / t of compound collector as second cleaning reagent; 200-300 g / t of compound collector as first scavenging reagent; and 100-200 g / t of compound collector as second scavenging reagent.

5. The beneficiation method for low-grade spodumene according to claim 1, characterized in that, In step S2, the reverse flotation process of the slime includes a primary roughing stage.

6. The beneficiation method for low-grade spodumene according to claim 5, characterized in that, The first preset reagent is 20-40 g / t of coconut oil amine as a roughing agent.

7. The beneficiation method for low-grade spodumene according to claim 4, characterized in that, The stirring time for adding the modifier is 2-3 minutes; the stirring time for adding the compound inhibitor is 2-3 minutes; the stirring time for adding the compound collector is 2-3 minutes.

8. The beneficiation method for low-grade spodumene according to claim 4, characterized in that, In step S3, the obtained lithium concentrate contains up to 4.68% Li2O, with a recovery rate as high as 66.49%.

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