Flotation inhibitor and preparation method and application thereof

Abstract

The invention provides a flotation inhibitor and a preparation method and application thereof, and relates to the technical field of mineral separation. The flotation inhibitor comprises the following raw materials in parts by mass: 10-50 parts of sodium carbonate, 4-20 parts of sodium hexametaphosphate, 7-40 parts of larch tannin extract, 1-5 parts of modified starch, 2-10 parts of sodium hydroxide and 10-20 parts of water. The flotation inhibitor provided by the invention is applied to a flotation process of fine lepidolite, and the recovery rate can be increased.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, and in particular to a flotation inhibitor, its preparation method, and its application. Background Technology

[0002] Lepidolite, a key raw material for lithium extraction, is widely mined across various regions, with Yichun, known as China's "Lithium Capital," possessing exceptionally rich lepidolite resources. However, due to a lack of advanced beneficiation technology, lithium resources are severely wasted, with 20%-30% of these resources failing to be effectively recovered due to the removal of fine mud during the processing. Although numerous research institutes and reagent manufacturers have dedicated themselves to developing collectors with strong resistance to fine mud interference, the results have been minimal. Conventional modifier formulations (sodium hexametaphosphate + sodium carbonate) require excessive amounts of lepidolite from fine mud and have low recovery rates; based on current lepidolite market prices, the cost far exceeds the value of the separated lepidolite. Summary of the Invention

[0003] Based on the technical problems existing in the background art, the present invention proposes a flotation inhibitor, its preparation method and application.

[0004] The present invention proposes a flotation inhibitor comprising the following raw materials in parts by weight: 10-50 parts sodium carbonate, 4-20 parts sodium hexametaphosphate, 7-40 parts larch tannin, 1-5 parts modified starch, 2-10 parts sodium hydroxide, and 10-20 parts water.

[0005] The flotation inhibitor of this invention uses simple and low-cost raw materials, and the synergistic effect between the various raw materials helps to improve the recovery rate of fine-grained lepidolite.

[0006] Preferably, the modified starch is selected from one or more of acetate starch, hydroxypropyl starch, carboxymethyl starch, phosphate starch, and hydroxypropyl distarch phosphate.

[0007] Modified starch, due to its unique molecular structure, has the advantages of low dosage, good dispersibility, and good inhibition of metal ions such as Fe, which can solve the problem of poor sorting caused by oleic acid substances in the collector.

[0008] Preferably, the mass ratio of larch tannin to modified starch is (1.5-8):1.

[0009] This invention introduces a flotation inhibitor obtained by combining larch tannin and modified starch. The synergistic effect between the two helps to obtain an inhibitor with high dispersibility, strong inhibition ability, good selectivity and wide range.

[0010] This invention also proposes a method for preparing a flotation inhibitor, comprising the following steps: first, water and larch tannin are stirred evenly at speed R1; then, sodium hydroxide is added and stirred evenly at speed R2; then, sodium carbonate, sodium hexametaphosphate, and modified starch are added sequentially and stirred evenly at speed R3 to obtain the desired flotation inhibitor.

[0011] The flotation inhibitor preparation method provided by this invention is simple and of great significance to actual production in enterprises.

[0012] Preferably, R1 is 50-100 rpm, R2 is 150-200 rpm, and R3 is 100-150 rpm.

[0013] Controlling the rotation speed within a certain range helps the drug dissolve fully.

[0014] Preferably, the flotation inhibitor solution is an aqueous solution of flotation inhibitor, and the preparation of the flotation inhibitor solution includes mixing the flotation inhibitor with water evenly; the mass fraction of the flotation inhibitor solution is 3wt%-10wt%.

[0015] Application of the above-mentioned flotation inhibitor or the flotation inhibitor prepared by the above-mentioned method in the flotation of fine-grained lepidolite.

[0016] Preferably, 90%-100% of the fine-grained lepidolite has a particle size of less than 38 μm.

[0017] The flotation inhibitor provided by this invention can be used for the flotation of fine-grained lepidolite with a particle size of less than 38μm accounting for 90%-100%, solving the problem of fine mud being removed and unable to be effectively recovered in the existing process.

[0018] Preferably, the method for flotation of fine-grained lepidolite includes the following steps:

[0019] S1. Primary roughing: Fine-grained lepidolite and water are mixed to form a slurry. Flotation inhibitor solution and collector are added to the slurry, stirred evenly, and aerated and skimmed to obtain rough concentrate and rough tailings.

[0020] S2, Primary scavenging: Add collector to coarse tailings, stir evenly, aerate and scrape bubbles to obtain scavenged concentrate and scavenged tailings;

[0021] S3, Two-stage cleaning: Add flotation inhibitor solution to the rough concentrate and scavenging concentrate and feed them into the first cleaning flotation operation to obtain the first cleaning froth and the first cleaning middlings; feed the first cleaning froth into the second cleaning flotation operation to obtain lepidolite concentrate and the second cleaning middlings.

[0022] This invention addresses the issue of improving the flotation efficiency of lepidolite when the particle size is fine and without altering existing processes. By using the flotation inhibitor provided by this invention, the flotation efficiency of lepidolite can be significantly improved, thereby increasing the utilization efficiency of lithium resources. This is of great significance to the actual production of enterprises.

[0023] Preferably, in S1, the solid content of the slurry is 30%-50%.

[0024] A solids content in the slurry within a certain range helps ensure the effectiveness of subsequent mineral flotation and the economic value of the enterprise.

[0025] Preferably, in S1, the amount of flotation inhibitor used is 300-500 g / t.

[0026] During the roughing process, the dosage of flotation depressants, within a certain range, helps to disperse the pulp and suppress gangue minerals.

[0027] Preferably, in S1, the amount of collector used is 400-600 g / t.

[0028] During the roughing process, the amount of collector used within a certain range can help in the separation and collection of valuable minerals.

[0029] Preferably, in S1 and S2, the collector is Jiangxi Xinlicheng Materials Technology Co., Ltd.'s 306 collector.

[0030] Preferably, in S2, the amount of collector used is 200-300 g / t.

[0031] During the scavenging process, the amount of collector used within a certain range helps to recover the remaining useful minerals after the S1 operation and reduces the floatation of gangue minerals.

[0032] Preferably, in step S3, the amount of flotation inhibitor used is 50-200 g / t.

[0033] During the selection process, the dosage of flotation inhibitors within a certain range helps to disperse and suppress gangue minerals that are inevitably included in the S1 flotation process, thereby increasing the unit content of useful minerals.

[0034] Preferably, in S1 and S3, the mass fraction of the flotation inhibitor solution is 3wt%-10wt%.

[0035] Having a certain mass fraction of flotation inhibitor solution helps to better and more accurately control the impact of reagent dosage on flotation performance.

[0036] The beneficial effects of this invention are as follows:

[0037] This invention addresses the issue of lepidolite inhibitors synthesized using different component reagents to significantly improve the separation efficiency of lepidolite under conditions of fine particle size. Compared with traditional lepidolite inhibitors, these inhibitors exhibit better dispersibility, stronger inhibition ability, better selectivity, and a wider range of applications. Without altering existing processes, this invention enables the recovery of lepidolite from fine mud during desliming and flotation, thereby improving the utilization efficiency of lithium resources. This is of great significance to the actual production of enterprises.

[0038] The larch tannin in this invention's flotation inhibitor, after hydrolysis and alkalization, generates a large amount of sodium tannate. Sodium tannate has multiple hydroxyl groups, giving it strong hydrophilicity. This not only inhibits gangue minerals such as quartz and feldspar but also shields against the adverse effects of Ca and Mg ions in water, and exhibits good dispersibility. By introducing larch tannin in synergy with modified starch, the recovery rate of fine-grained lepidolite is improved. Detailed Implementation

[0039] The technical solution of the present invention will be described in detail through specific embodiments.

[0040] In the following embodiments, the specific information regarding the raw materials used is as follows:

[0041] The modified starch is acetate starch from Dezhou Gaofeng Starch Co., Ltd.

[0042] Collector: Manufacturer: Jiangxi Xinlicheng Materials Technology Co., Ltd., Grade: 306.

[0043] Unless otherwise specified, all materials and reagents used in the following examples and comparative examples are commercially available.

[0044] Example 1

[0045] A method for preparing a flotation inhibitor includes the following steps: first, 10 parts of water and 15 parts of larch tannin are stirred evenly at 100 rpm; then, 5 parts of sodium hydroxide are added and stirred evenly at 200 rpm; then, 10 parts of sodium carbonate, 5 parts of sodium hexametaphosphate, and 2 parts of modified starch are added sequentially and stirred evenly at 150 rpm to obtain the inhibitor.

[0046] The above flotation inhibitor was mixed evenly with water to obtain a flotation inhibitor solution with a mass fraction of 5 wt%.

[0047] application:

[0048] The fine-grained lepidolite was fine mud from a lepidolite beneficiation plant in Yifeng, Jiangxi Province, with a Li2O grade of 0.35% and a -400 mesh content of 95%.

[0049] The method for flotation of fine-grained lithium mica includes the following steps:

[0050] S1. First roughing: Add 425g of fine-grained lepidolite to the flotation machine, add water to prepare a slurry with a concentration of 40%, add 3mL of 5wt% flotation inhibitor solution (flotation inhibitor content is 350g / t), stir for 3min, then add 500g / t collector, stir thoroughly and start aeration and skimming to obtain rough concentrate and rough tailings. The rough tailings in the tank continue to be scavenged.

[0051] S2, Primary scavenging: Add 250g / t collector to the coarse tailings, stir thoroughly, and then start aeration and frothing to obtain scavenged concentrate. The ore in the tank will be the scavenged tailings.

[0052] S3, Two Selections

[0053] Selecting 1: The rough concentrate obtained from S1 and the scavenging concentrate obtained from S2 are fed into the selecting 1 flotation operation. Specifically, 1 mL of 5 wt% flotation inhibitor solution (flotation inhibitor content is 116 g / t) is added, and after stirring for 2 min, aeration and frothing are started to obtain the selecting 1 froth product and the selecting 1 middlings product.

[0054] Selected flotation 2: The froth product from Selected Flotation 1 is fed into Selected Flotation 2. After thorough stirring, aeration and frothing are started to obtain lepidolite concentrate and middlings product from Selected Flotation 2.

[0055] The obtained lepidolite concentrate had a Li2O content of 1.82%, and the S2 tailings product had a Li2O grade of 0.15%, with a recovery rate of 62.27%.

[0056] Example 2

[0057] A 5 wt% flotation inhibitor solution was prepared according to Example 1.

[0058] Application: The fine-grained lepidolite was fine mud from a lepidolite beneficiation plant in Yifeng, Jiangxi Province, with a Li2O grade of 0.31% and a -400 mesh content of 93%. Following the flotation method of fine-grained lepidolite in Example 1, the lepidolite concentrate had a Li2O content of 1.82%, and the S2 tailings product had a Li2O grade of 0.15%, with a recovery rate of 62.27%.

[0059] Example 3

[0060] A 5 wt% flotation inhibitor solution was prepared according to Example 1.

[0061] Application: The fine-grained lepidolite was fine mud from a lepidolite beneficiation plant in Yifeng, Jiangxi Province, with a Li2O grade of 0.42% and a -400 mesh content of 97%. Following the flotation method of fine-grained lepidolite in Example 1, the lepidolite concentrate was obtained with a Li2O content of 2.04%, and the S2 tailings product had a Li2O grade of 0.18%, with a recovery rate of 62.67%.

[0062] In summary, the flotation inhibitor provided by this invention, when applied to the flotation process of fine-grained lepidolite, helps to improve the recovery rate.

[0063] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A flotation inhibitor, characterized in that, The raw materials include the following parts by weight: 10-50 parts sodium carbonate, 4-20 parts sodium hexametaphosphate, 7-40 parts larch tannin, 1-5 parts modified starch, 2-10 parts sodium hydroxide, and 10-20 parts water.

2. The flotation depressant according to claim 1, characterized in that, The modified starch is selected from one or more of acetate starch, hydroxypropyl starch, carboxymethyl starch, phosphate starch, and hydroxypropyl distarch phosphate; the mass ratio of larch tannin to modified starch is (1.5-8):

1.

3. A method for preparing the flotation inhibitor according to any one of claims 1-2, characterized in that, The process includes the following steps: First, mix water and larch tannin at speed R1 until homogeneous. Then, add sodium hydroxide and mix at speed R2 until homogeneous. Next, add sodium carbonate, sodium hexametaphosphate, and modified starch in sequence and mix at speed R3 until homogeneous.

4. The preparation method according to claim 3, characterized in that, R1 is 50-100 rpm, R2 is 150-200 rpm, and R3 is 100-150 rpm.

5. The application of a flotation inhibitor according to any one of claims 1-2 or a flotation inhibitor prepared by the preparation method according to any one of claims 3-4 in the flotation of fine-grained lepidolite, characterized in that, The fine-grained lepidolite comprises 90%-100% particles with a size less than 38μm.

6. The application according to claim 5, characterized in that, The method for flotation of fine-grained lithium mica includes the following steps: S1. Primary roughing: Fine-grained lepidolite and water are mixed to form a slurry. Flotation inhibitor solution and collector are added to the slurry, stirred evenly, and aerated and skimmed to obtain rough concentrate and rough tailings. S2, Primary scavenging: Add collector to coarse tailings, stir evenly, aerate and scrape bubbles to obtain scavenged concentrate and scavenged tailings; S3, Two-stage cleaning: Add flotation inhibitor solution to the rough concentrate and scavenging concentrate and feed them into the first cleaning flotation operation to obtain the first cleaning froth and the first cleaning middlings; feed the first cleaning froth into the second cleaning flotation operation to obtain lepidolite concentrate and the second cleaning middlings.

7. The application according to claim 6, characterized in that, In S1 and S3, the flotation inhibitor solution is an aqueous solution of flotation inhibitor; the mass fraction of the flotation inhibitor solution is 3wt%-10wt%.

8. The application according to claim 6, characterized in that, In S1, the solid content of the slurry is 30%-50%, the dosage of flotation depressant is 300-500 g / t, and the dosage of collector is 400-600 g / t.

9. The application according to claim 6, characterized in that, In S2, the amount of collector used is 200-300 g / t.

10. The application according to claim 6, characterized in that, In S3, the amount of flotation inhibitor used is 50-200 g / t.