A gangue depressant for spodumene flotation and methods of use thereof

Abstract

The present application belongs to the technical field of flotation reagent, and particularly relates to a gangue inhibiting reagent for spodumene flotation and a use method thereof. The inhibiting reagent is composed of oxalic acid, ethylenediamine and aluminum ammonium sulfate, and the use method is to configure a certain amount of oxalic acid, ethylenediamine and aluminum ammonium sulfate into a solution with a proper concentration, add the solution into the stirred spodumene slurry according to a certain adding order and interval time after the addition of sodium carbonate, add a collector after a certain stirring time, and then carry out flotation after a certain stirring time. The present application can realize efficient and selective inhibition of gangue minerals in spodumene flotation, and the inhibition method formed by the synergistic reaction of oxalic acid, ethylenediamine and aluminum ammonium sulfate has the advantages of easy availability of raw materials, convenient operation and good selective inhibition effect, and has important and positive significance for improving spodumene flotation and improving the efficiency of mineral processing.

Description

Technical Field

[0001] This invention belongs to the field of flotation reagent technology, specifically relating to a gangue inhibitor for spodumene flotation and its application method. Background Technology

[0002] The new energy industry plays a vital role in energy conservation, emission reduction, and addressing climate change. Lithium is a key strategic metal in the new energy industry. Developing efficient lithium resource utilization is crucial for ensuring lithium resource supply and the sustainable development of the new energy industry.

[0003] Spodumene is one of the three major sources of lithium resources: lithium from salt lakes, spodumene, and lepidolite. Spodumene resources are often characterized by poor endowment, low lithium grade, complex composition, fine crystal size, and high difficulty in beneficiation, which poses a significant challenge to the efficient beneficiation and enrichment of spodumene.

[0004] Spodumene flotation is an important method for enriching lithium in mineral processing. Currently, sodium carbonate is generally used as a modifier in the industrial spodumene flotation process. While it adjusts and disperses the slime, it also has a certain inhibitory effect on feldspar and quartz gangue minerals. However, when sodium carbonate is used alone, its selective inhibition effect on feldspar and quartz gangue minerals is not good. In production practice, the dosage of sodium carbonate needs to be precisely controlled. Too little sodium carbonate has little inhibitory effect, while too much easily inhibits spodumene flotation. Therefore, there is an urgent need for a method that can strongly selectively inhibit gangue minerals to achieve efficient spodumene flotation.

[0005] In recent years, the work done by mineral processing professionals on spodumene flotation suppression has mainly focused on conventional mineral processing depressants, such as inorganic depressants, small-molecule organic depressants, and organic polymer depressants. These are either used alone or in simple combinations, often failing to achieve both strong suppression and good selectivity, resulting in limited effectiveness. This is not only due to the poor suppression performance of the raw materials themselves, but also largely due to a lack of innovative methods for simple combinations, making it difficult to effectively balance both suppression of gangue minerals and selectivity.

[0006] Based on the above background analysis, this invention proposes a gangue suppression method for spodumene flotation, which aims to enhance the synergistic suppression effect by combining and inhibiting chemical reactions, thereby achieving a stronger selective suppression capability for use in the field of spodumene ore flotation. Summary of the Invention

[0007] This invention aims to provide a method for suppressing gangue formation in spodumene flotation, proposing a method that uses the synergistic reaction of oxalic acid, ethylenediamine, and ammonium aluminum sulfate to efficiently and selectively suppress gangue mineral formation in spodumene flotation.

[0008] The objective of this invention is achieved through the following technical solution: a gangue inhibitor for spodumene flotation, comprising oxalic acid, ethylenediamine, and ammonium aluminum sulfate. These three raw materials can be of analytical grade, chemical grade, or industrial grade, etc. The types of raw materials claimed in this invention include, but are not limited to, these three raw materials as raw material sources.

[0009] Furthermore, it also includes water, wherein the oxalic acid, ethylenediamine and aluminum ammonium sulfate are respectively prepared into solutions with a mass fraction of 2-20% by adding water.

[0010] Furthermore, the ratio of oxalic acid, ethylenediamine, and ammonium aluminum sulfate is 2-10:1-6:4-16.

[0011] The present invention also provides a method for using the above-mentioned gangue inhibitor in spodumene flotation, characterized by comprising the following steps: after the addition of the modifier in the spodumene flotation process, oxalic acid, ethylenediamine and aluminum ammonium sulfate are added at intervals, with aluminum ammonium sulfate being added last, and the interval is 3-10 minutes.

[0012] Furthermore, the dosage of oxalic acid is 100-500 grams per ton of raw ore, the dosage of ethylenediamine is 50-300 grams per ton of raw ore, and the dosage of ammonium aluminum sulfate is 200-800 grams per ton of raw ore.

[0013] Furthermore, the modifier is sodium carbonate, used at a dosage of 500-2000 grams per ton of raw ore, and the sodium carbonate is diluted with water to a concentration of 2-20% by mass before use.

[0014] Furthermore, the order in which the reagents are added in the spodumene flotation process is as follows: modifier, the aforementioned gangue inhibitor, and collector.

[0015] Furthermore, the reagent needs to be added after a grinding process to achieve sufficient individual liberation of spodumene and gangue minerals; sufficient individual liberation of minerals means that the proportion of separated non-intergrowth mineral particles is more than 80% of the total minerals. Preferably, the modifier is added in the grinding mill or in the slurry in the stirred tank after grinding.

[0016] Furthermore, when adding the reagent, the stirring speed should be controlled at 300-1500 rpm so that the reagent is added to the slurry under turbulent stirring conditions.

[0017] Furthermore, the collector is an anionic surfactant such as fatty acid or sodium fatty acid as a collector for spodumene, and its dosage is 1000-3000 grams per ton of raw ore.

[0018] The main innovative features of this invention are as follows:

[0019] I. Oxalic acid has a strong inhibitory effect on silicate gangue minerals (such as feldspar). Ethylenediamine is a small-molecule cationic amine compound. Oxalic acid reacts with ethylenediamine to produce ethylenediaminetetraacetic acid, as shown in the following reaction formula:

[0020] 4C2H2O4 + C2H8N2 → C 10 H 16 N2O8

[0021] In the slurry solution, the ethylenediaminetetraacetic acid generated by the reaction co-adsorbs with oxalic acid and ethylenediamine on the mineral surface, and the synergistic effect enhances the inhibition ability.

[0022] Second, the generated ethylenediaminetetraacetic acid has a strong metal ion chelating ability, forming chelates with cations in ammonium aluminum sulfate and metal cations on mineral surfaces, thereby enhancing the inhibition ability.

[0023] Third, the ethylenediaminetetraacetic acid (EDTA) produced by the reaction of oxalic acid adsorbed on the surface of gangue minerals with ethylenediamine has a carboxyl group (-COOH) that prevents the re-adsorption of carboxyl groups in the collector on the surface of gangue minerals, thereby enhancing the selective inhibition ability of the inhibitor on gangue minerals.

[0024] Fourth, compared with adding ethylenediaminetetraacetic acid (EDTA) separately to the pulp as a depressant, the method of generating EDTA through reaction in this invention not only utilizes the depressant effect of EDTA, but also allows the amino groups (-NH2) in the residual ethylenediamine molecules in the pulp to synergistically form anionic and cation co-adsorption with the fatty acid anionic collector, thereby enhancing the collector's ability to collect the target mineral and facilitating flotation.

[0025] The beneficial effects of this invention are as follows: The gangue suppression method for spodumene flotation of this invention utilizes the synergistic effect of ethylenediaminetetraacetic acid (EDTA) generated through a chemical reaction, which co-adsorbs with the raw materials oxalic acid, ethylenediamine, ammonium aluminum sulfate, and collectors. This enhances the selective suppression ability of gangue in spodumene flotation and improves the collecting performance of the collectors. Using this method to float spodumene ore can significantly improve concentrate grade and recovery rate, and can be widely applied in the field of spodumene ore flotation both domestically and internationally. Detailed Implementation

[0026] The technical solution of the present invention will be described in further detail below, but the scope of protection of the present invention is not limited to the following description.

[0027] Example 1

[0028] (1) Prepare the raw materials for the inhibitor. Oxalic acid, ethylenediamine, and ammonium aluminum sulfate are prepared into 10% solutions by mass. The dosage of oxalic acid is 300 g / ton of raw ore, the dosage of ethylenediamine is 200 g / ton of raw ore, and the dosage of ammonium aluminum sulfate is 500 g / ton of raw ore.

[0029] (2) Add the reaction mixture in sequence. The three raw materials mentioned in step 1 are added after sodium carbonate has been added. The order of addition of the three raw materials is as follows: oxalic acid, ethylenediamine, and ammonium aluminum sulfate. There should be a 10-minute interval between the addition of two adjacent raw materials.

[0030] (3) Flotation with collector added. Following the spodumene flotation process, flotation is carried out under conditions where the minerals are fully liberated through grinding. All reagents are added to the slurry under turbulent stirring, in the order of sodium carbonate, depressant, and collector. The degree of mineral liberation is 85%, the stirring speed is 1200 rpm, sodium carbonate is added to the mill at a dosage of 1000 g / ton of raw ore, and the collector dosage is 1500 g / ton of raw ore.

[0031] Table 1 shows the comparative results of the gangue suppression method for spodumene flotation according to the present invention. The test ore was a pegmatite-type spodumene mine in southern Xinjiang. The ore was subjected to a crushing-grinding-flotation process. The flotation process consisted of a closed-circuit test process with one roughing stage, one scavenging stage, and two cleaning stages. The indicators obtained by the suppression method according to the embodiments of the present invention and the conventional water glass suppression method were compared while keeping all other process flows the same (Table 1).

[0032] Table 1. Results of comparative experiments on inhibition methods.

[0033]

[0034]

[0035] As shown in Table 1, the method of the present invention can significantly improve the grade and recovery rate of Li2O concentrate, and the implementation effect is good.

[0036] Example 2

[0037] (1) Prepare the raw materials for the inhibitor. Oxalic acid, ethylenediamine, and ammonium aluminum sulfate are each prepared into a 10% mass fraction solution for use. The dosage of oxalic acid is 400 g / ton of raw ore, the dosage of ethylenediamine is 250 g / ton of raw ore, and the dosage of ammonium aluminum sulfate is 400 g / ton of raw ore.

[0038] (2) Add the reaction mixture in sequence. The three raw materials mentioned in step 1 are added after sodium carbonate has been added. The order of addition of the three raw materials is as follows: oxalic acid, ethylenediamine, and ammonium aluminum sulfate. There should be a 10-minute interval between the addition of two adjacent raw materials.

[0039] (3) Flotation with collector added. Following the spodumene flotation process, flotation is carried out under conditions where the minerals are fully liberated through grinding. All reagents are added to the slurry under turbulent stirring, in the order of sodium carbonate, depressant, and collector. The degree of mineral liberation is 88%, the stirring speed is 1200 rpm, sodium carbonate is added to the mill at a dosage of 1300 g / ton of raw ore, and the collector dosage is 1400 g / ton of raw ore.

[0040] Table 2 shows the comparative results of the gangue suppression method for spodumene flotation according to the present invention. The test ore was a pegmatite-type spodumene ore from the Keeryin area in western Sichuan. The ore was subjected to a crushing-grinding-flotation process, with flotation being a single roughing operation. The indicators obtained by comparing the suppression method according to the embodiments of the present invention with those obtained by the conventional water glass suppression method while keeping all other process flows the same (Table 2).

[0041] Table 2. Results of comparative experiments on inhibition methods.

[0042]

[0043] As shown in Table 2, the method of the present invention can significantly improve the grade and recovery rate of Li2O in crude concentrate, and the implementation effect is good.

[0044] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A method for using a gangue inhibitor in spodumene flotation, characterized in that, The gangue inhibitor includes oxalic acid, ethylenediamine, and aluminum ammonium sulfate; the method of using the gangue inhibitor includes the following steps: in the spodumene flotation process, after the step of adding the modifier, oxalic acid, ethylenediamine, and aluminum ammonium sulfate are added at intervals, with aluminum ammonium sulfate being added last, and the interval is 3-10 minutes.

2. The method of using the gangue inhibitor in spodumene flotation according to claim 1, characterized in that, The gangue inhibitor also includes water, and the oxalic acid, ethylenediamine and aluminum ammonium sulfate are respectively prepared into a 2-20% mass fraction solution by adding water.

3. The method of using a gangue inhibitor for spodumene flotation according to claim 1 or 2, characterized in that, The mass ratio of oxalic acid, ethylenediamine, and ammonium aluminum sulfate is 2~10:1~6:4~16.

4. The method of using the gangue inhibitor in spodumene flotation according to claim 1, characterized in that, The dosage of oxalic acid is 100-500 grams per ton of raw ore, the dosage of ethylenediamine is 50-300 grams per ton of raw ore, and the dosage of ammonium aluminum sulfate is 200-800 grams per ton of raw ore.

5. The method of using the gangue inhibitor in spodumene flotation according to claim 1, characterized in that, The modifier is sodium carbonate, used at a dosage of 500-2000 grams per ton of raw ore. The sodium carbonate is diluted with water to a concentration of 2-20% by mass before use.

6. The method of using the gangue inhibitor in spodumene flotation according to claim 1, characterized in that, The order in which reagents are added in the spodumene flotation process is as follows: modifier, gangue inhibitor, and collector.

7. The method of using the gangue inhibitor in spodumene flotation according to claim 6, characterized in that, Before adding the reagent, a grinding process is required to achieve complete individual dissociation of spodumene minerals and gangue minerals.

8. The method of using the gangue inhibitor in spodumene flotation according to claim 1, characterized in that, When adding the reagent, the stirring speed should be controlled at 300-1500 rpm so that the reagent is added to the slurry in a turbulent stirring state.

9. The method of using the gangue inhibitor in spodumene flotation according to claim 6, characterized in that, The collector is a fatty acid or sodium fatty acid.

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