Composite inhibitor for separating calcium-containing gangue minerals in non-ferrous metals and application of composite inhibitor

Abstract

The invention discloses a composite inhibitor for separation of calcium-containing gangue minerals in nonferrous metals and application thereof.The composite inhibitor comprises a component A and a component B. The component A is carboxymethyl cellulose, the component B is Cu < 2 + > ions or Fe < 3 + > ions, and the Cu < 2 + > ions or Fe < 3 + > ions are provided by soluble copper salt containing Cu < 2 + > or soluble iron salt containing Fe < 3 + >. Through the synergistic effect of the metal ions and the carboxymethyl cellulose, the technical problems that a traditional inhibitor is insufficient in calcium-containing gangue inhibition strength and poor in selectivity are solved. The composite inhibitor can strongly inhibit the flotation recovery rate of calcium-containing gangue minerals such as calcite and fluorite at an extremely low level of 2.5% or below, so that the selective efficiency of flotation separation of target minerals and calcium-containing gangue is remarkably improved, and the composite inhibitor is wide in applicable pH range and convenient to use.

Description

TECHNICAL FIELD

[0001] The present application relates to a composite depressant for separating calcium-containing gangue minerals in non-ferrous metals and application thereof, and belongs to the technical field of mineral processing reagents. BACKGROUND

[0002] In the process of tin stone flotation, the efficient separation of tin stone and calcium-containing gangue minerals such as calcite is a long-standing technical problem. The commonly used fatty acid collectors (such as sodium oleate) have poor selectivity for the two, resulting in unsatisfactory separation effect. In order to improve the selectivity, carboxymethyl cellulose (CMC) is often used as a depressant. However, single CMC will non-selectively adsorb on the surface of tin stone while inhibiting calcite, resulting in a significant decrease in tin stone recovery rate, and its inhibitory effect is easily disturbed by inevitable ions (such as Ca 2+ ) in the slurry, and its stability is insufficient. In addition to carboxymethyl cellulose, other types of depressants are often used in existing technologies to improve the selective inhibition of calcium-containing gangue, such as starch-based depressants (such as corn starch), lignin sulfonate, and polyacrylic acid depressants. However, the application effect of these depressants in the tin stone-calcium-containing gangue system is not ideal. Although starch-based depressants have a certain inhibitory effect, their inhibitory behavior lacks sufficient selectivity, often producing strong inhibition on tin stone, resulting in a serious decrease in tin stone recovery rate; at the same time, the viscosity of starch is large, which may worsen the properties of flotation froth and affect the separation efficiency. The inhibitory capacity of lignin sulfonate is generally weak, making it difficult to achieve high-intensity inhibition of calcium-containing gangue. Polyacrylic acid depressants also have the problem of poor selectivity due to their strong dispersibility and chelating ability, which easily competes with the collector for adsorption on the surface of tin stone, which is not conducive to the recovery of tin stone.

[0003] Further, in the published patent schemes for composite depressants for calcium-containing gangue, there are still obvious limitations in the technical path. For example, in patent CN120243281 A, a five-component composite system composed of sodium hexametaphosphate, sodium humate, rubber, water glass, and sodium acrylate is used. Although this scheme utilizes the synergistic effect of multiple components, the components are too complex and need to be prepared in advance, which is not convenient for industrial application. The inhibitory mechanism mainly relies on the competitive adsorption and coverage of multiple polymers on the mineral surface, and the selectivity protection ability for the target mineral (such as tin stone) is insufficient. The experimental data show that while effectively inhibiting calcium-containing gangue, the recovery rate of the target mineral may still suffer a large loss, failing to achieve a balance between "strong inhibition" and "high selectivity". For example, in patent CN120571699 A, flavonoid organic matter (breviscapine) and aluminum ions (Al 3 +This is a pre-complexed inhibitor. The drawbacks of this approach are: the core organic component, scutellarin, is expensive and has an unstable source; the operating environment must be maintained under strongly alkaline conditions (pH 9.0-9.5), limiting its applicability; and its technical approach does not involve Cu, which is of particular significance for cassiterite flotation. 2+ / Fe 3+ The innovative use of metal ions is disconnected from the technological background of solving the problem of cassiterite flotation.

[0004] Currently, specific metal ions (Cu) 2+ / Fe 3+ The combination of cassiterite and carboxymethyl cellulose, achieved through a simple sequential addition method, utilizes the bridging effect of metal ions to produce a synergistic effect with carboxymethyl cellulose, thereby achieving high-intensity and high-selectivity inhibition of calcium-containing gangue. However, this method has not been reported before. Therefore, developing a novel composite inhibitor that is simple in composition, low in cost, has mild applicable conditions, and can achieve synergistic effects is crucial for solving the problem of efficient flotation separation of cassiterite and calcium-containing gangue. Summary of the Invention

[0005] To address the shortcomings of existing technologies where carboxymethyl cellulose exhibits insufficient selectivity for inhibiting calcium-bearing gangue minerals (such as calcite) and is susceptible to interference from unavoidable ions in the pulp, this invention provides a composite inhibitor. This composite inhibitor utilizes a specific metal ion, Cu... 2+ / Fe 3+ The synergistic effect with carboxymethyl cellulose can achieve high-intensity and high-selectivity inhibition of calcium-containing gangue minerals, while basically not affecting the floatability of the target mineral (such as cassiterite), thereby significantly improving the flotation separation efficiency between the target mineral and the calcium-containing gangue minerals.

[0006] The composite inhibitor of this invention comprises component A and component B, wherein component A is carboxymethyl cellulose and component B is Cu. 2+ ions or Fe 3+ The mass ratio of ions, component A, to component B is 10:1 to 1:5 on a dry basis. The Cu... 2+ ions or Fe 3+ Ions containing Cu 2+ Soluble copper salts or containing Fe 3+ It provides soluble iron salts.

[0007] The soluble copper salt is one or more of copper sulfate, copper chloride, or copper nitrate; the soluble iron salt is one or more of ferric chloride, ferric sulfate, or ferric nitrate.

[0008] The degree of substitution (DS) of component A, carboxymethyl cellulose, is 0.4 to 1.2, preferably 0.6 to 0.9.

[0009] The weight average molecular weight of carboxymethyl cellulose is 20,000 to 200,000 Daltons.

[0010] The composite inhibitor of this invention is used for the separation of non-ferrous metals such as lead, zinc, and tin from calcium-containing gangue. The specific steps are as follows: (1) Grind and adjust the pulp of the non-ferrous metal ore containing calcium gangue minerals to obtain the ore pulp to be flotated; (2) Adjust the pH value of the flotation pulp in step (1), and then add component B and component A to the pulp in sequence and stir to adjust the pulp; (3) Add fatty acid collectors to the slurry from step (2) for flotation separation to obtain non-ferrous metal concentrate.

[0011] Adjust the pH of the pulp to 6.5–8.5. Within this pH range, the synergistic inhibitory effect of metal ions and carboxymethyl cellulose is optimal.

[0012] The fatty acid collector in step (3) is sodium oleate, and the dosage is 300 g / t.

[0013] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention uses specific metal ions (Cu) 2+ or Fe 3+ When combined with carboxymethyl cellulose, a significant synergistic effect is generated among the components, which can suppress calcium-containing gangue minerals (such as calcite) with high strength and high selectivity, while basically not affecting the flotation of the target mineral, thus achieving efficient flotation separation of the target mineral and calcium-containing gangue.

[0014] (2) The composite inhibitor of the present invention effectively overcomes the shortcomings of single carboxymethyl cellulose, such as poor selectivity and susceptibility to interference from unavoidable ions in the ore pulp. In actual ore flotation tests, tin concentrate with a Sn grade of more than 3.5% and a recovery rate of more than 66% can be obtained, while the recovery rate of calcium gangue (calculated as CaO) is strongly suppressed to an extremely low level of less than 2.5%, with excellent separation indicators.

[0015] (3) The composite inhibitor of the present invention has a clear composition, simple preparation and application methods, and can maintain good effects within a wide range of reagent ratios and pulp pH. It has strong process adaptability, controllable cost, and is very suitable for industrial application. The raw materials used (carboxymethyl cellulose, copper sulfate, etc.) are all bulk chemical products, which are easy to obtain and have good compatibility with existing flotation processes. They are especially suitable for processing difficult-to-process ores in which cassiterite and calcium gangue are closely associated, and have broad prospects for industrial application. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the process flow for the application of the composite inhibitor described in this invention in the flotation of cassiterite. Detailed Implementation

[0017] The present invention will be further described below with reference to specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0018] All reagents and instruments used in the following examples are commercially available. The actual ore sample used was gravity separation tailings from a tin mine in Yunnan Province. The cassiterite in this tailings was finely disseminated and closely associated with calcium-bearing gangue (mainly calcite and fluorite), making separation using a single flotation process difficult. The multi-element chemical analysis results of the actual ore sample showed a Sn grade of 0.45%, a CaO content of 18.36%, and a CaF₂ content of 15.22%.

[0019] Flotation tests and reagent preparations all used recycled water from the plant to closely approximate actual industrial conditions. Unless otherwise specified, the flotation process in the following examples and comparative examples involves a single roughing flotation stage with a flotation time of 4 minutes.

[0020] Example 1: Cu 2+ Application of carboxymethyl cellulose complex inhibitors

[0021] This embodiment demonstrates Cu 2+ The effect of the systemic compound inhibitor.

[0022] Flotation steps: (1) Take 500g of mineral sample and place it in a flotation machine, add tap water to adjust the slurry; (2) Stir and adjust the slurry for 2 minutes, and adjust the pH of the slurry to 7.5 with sodium carbonate; (3) Add copper sulfate sequentially (in Cu) 2+ Add 80 g / t of carboxymethyl cellulose and stir for 3 minutes; then add 200 g / t of carboxymethyl cellulose and stir for 3 minutes. The degree of substitution (DS) of the carboxymethyl cellulose used is 0.7, and the weight average molecular weight (Mw) is 80,000 Daltons. Carboxymethyl cellulose and Cu 2+ The mass ratio of ions is 5:2, which falls within the preferred range of (5:1) to (1:2).

[0023] (4) Add sodium oleate (300 g / t), stir for 3 minutes, then aerate and skim off the bubbles.

[0024] The results are shown in Table 1.

[0025] Table 1. Results of flotation test in Example 1

[0026] The results showed that the composite inhibitor achieved efficient recovery of cassiterite (Sn recovery rate 66.81%) while strongly suppressing the recovery rate of calcium gangue to an extremely low level (CaO 2.42%).

[0027] Example 2: Fe 3+ Application of carboxymethyl cellulose complex inhibitors This embodiment demonstrates Fe 3+ The system's effects and procedures are the same as in Example 1, the only difference being that copper sulfate is replaced with an equimolar amount of ferric chloride (in Fe...). 3+ The total concentration was 150 g / t. The carboxymethyl cellulose parameters used were the same as in Example 1 (DS=0.7, Mw=80,000 Da).

[0028] The results are shown in Table 2.

[0029] Table 2. Flotation test results of Example 2

[0030] Fe 3+ The system also achieved excellent performance indicators, proving that the composite inhibitor of the present invention has a positive effect on Cu. 2+ / Fe 3+ It has universal applicability.

[0031] Comparative Examples 1-4: Verification of the Effects of Single Components To demonstrate the necessity of the synergistic effect, a single-component control was set up.

[0032] Comparative Example 1: Sodium oleate (300 g / t) was added only, with no inhibitors.

[0033] Comparative Example 2: Carboxymethyl cellulose only (DS=0.7, Mw=80,000 Da, 200 g / t).

[0034] Comparative Example 3: Cu only 2+ (80 g / t).

[0035] Comparative Example 4: Fe only added 3+ (150 g / t).

[0036] The results are summarized in Table 3.

[0037] Table 3 Summary of flotation test results for Comparative Examples 1-4

[0038] Conclusion: A single component cannot simultaneously achieve both high cassiterite recovery and low gangue recovery; only the composite system of this invention can achieve this synergistic effect.

[0039] Comparative Example 5: Compared with traditional inhibitors Under the same conditions, a comparison was made with a conventional inhibitor at the same dosage (190 g / t).

[0040] Comparative Example 5-1: Using corn starch.

[0041] Comparative Example 5-2: Sodium lignosulfonate was used.

[0042] The results are shown in Table 4.

[0043] Table 4. Results of flotation test in Comparative Example 5 (compared with traditional inhibitors)

[0044] Conclusion: Traditional inhibitors are ineffective in this system, highlighting the advantages of this invention.

[0045] Comparative Example 6: Influence of Key Parameters—Carboxymethyl Cellulose Molecular Weight This comparative example is used to verify the effect of carboxymethyl cellulose molecular weight on the performance of the composite inhibitor, supporting the limitations of claim 3.

[0046] The flotation steps are basically the same as in Example 1, with Cu fixed. 2+ Dosage: 80 g / t, CMC dosage: 200 g / t (mass ratio 5:2), sodium oleate: 300 g / t, pH: 6.5~8.5. The only variable is the molecular weight of CMC. (1) Low molecular weight CMC: Mw ≈ 10,000 Da; (2) High molecular weight CMC: Mw ≈ 500,000 Da.

[0047] The results are shown in Table 5.

[0048] Table 5. Flotation results of Comparative Example 6-1 (CMC of different molecular weights)

[0049] Conclusion: Too low a molecular weight results in insufficient inhibition of membrane strength, while too high a molecular weight impairs selectivity.

[0050] Comparative Example 6-2: Effect of Degree of Substitution (DS) With Mw = 80,000 Da, change the CMC degree of substitution: (1) Low degree of substitution: DS ≈ 0.3 (below the range) (2) High degree of substitution: DS ≈ 1.5 (higher than the range) The results are shown in Table 6.

[0051] Table 6. Flotation results of Comparative Example 6-2 (CMC at different degrees of substitution)

[0052] Conclusion: If the substitution is too low, the carboxyl content will be insufficient; if it is too high, it may affect the adsorption conformation.

[0053] Comparative Example 7: Influence of Key Process Parameters—CMC and Cu 2+mass ratio To verify claim 4, CMC with DS=0.7 and Mw=80,000 Da was used at a fixed value, while its relationship with Cu was changed. 2+ Mass ratio: (1) 20:1 (CMC excess) (2) 1:10 (Cu 2+ excess) (3) CMC only (without Cu) 2+ ) The results are shown in Table 7.

[0054] Table 7. Flotation results of Comparative Example 7 (different CMC:Cu) 2+ (mass ratio)

[0055] Conclusion: The mass ratio is the key to the synergistic effect. Deviating from the scope of this invention ((10:1)~(1:5)) will lead to a significant deterioration in the separation index.

[0056] Comprehensive comparative analysis All key results are summarized in Table 8 for comprehensive comparison. For the sake of brevity, only the core indicators Sn recovery rate and CaO recovery rate are listed in the table.

[0057] Table 8 Comprehensive Comparative Analysis Table

[0058]

[0059] Table 8. Conclusion of Comprehensive Comparative Analysis 1. Significant synergistic effect: The composite inhibitor of this invention achieves a breakthrough separation effect—while achieving a high recovery rate of cassiterite (>66%), it strongly suppresses the recovery rate of the two main types of calcium-containing gangue to an extremely low level (<2.5%). This technical effect cannot be achieved by single components or traditional inhibitors.

[0060] 2. Parameter Range Supporting Effect: The molecular weight, degree of substitution, and mass ratio of carboxymethyl cellulose to metal ions are key factors in achieving and maintaining the aforementioned superior effects. Experimental data show that only when these parameters fall within the preferred range defined in the claims can the synergistic effect be fully realized and the separation index optimized.

[0061] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A composite inhibitor for the separation of calcium-containing gangue minerals from non-ferrous metals, characterized in that, The composite inhibitor comprises component A and component B, wherein component A is carboxymethyl cellulose and component B is Cu. 2+ ions or Fe 3+ The mass ratio of ions, component A to component B, is 10:1 to 1:5 on a dry basis.

2. The composite inhibitor for the separation of calcium-containing gangue minerals in non-ferrous metals according to claim 1, characterized in that: The Cu 2+ ions or Fe 3+ Ions containing Cu 2+ Soluble copper salts or containing Fe 3+ It provides soluble iron salts.

3. The composite inhibitor for the separation of calcium-containing gangue minerals in non-ferrous metals according to claim 1, characterized in that: The degree of substitution (DS) of component A, carboxymethyl cellulose, is 0.4 to 1.2, preferably 0.6 to 0.

9.

4. The composite inhibitor for the separation of calcium-containing gangue minerals in non-ferrous metals according to claim 2, characterized in that: The soluble copper salt is one or more of copper sulfate, copper chloride, or copper nitrate; the soluble iron salt is one or more of ferric chloride, ferric sulfate, or ferric nitrate.

5. The application of the composite inhibitor for the separation of calcium-containing gangue minerals from non-ferrous metals as described in claims 1-4, characterized in that, The specific steps are as follows: (1) Grind and adjust the pulp of the non-ferrous metal ore containing calcium gangue minerals to obtain the ore pulp to be flotated; (2) Adjust the pH value of the flotation pulp in step (1), and then add the composite inhibitor to the pulp, that is, add component B and component A in sequence, and stir to adjust the pulp; (3) Add fatty acid collectors to the slurry from step (2) for flotation separation to obtain non-ferrous metal concentrate.

6. The application of the composite inhibitor for the separation of calcium-containing gangue minerals in non-ferrous metals according to claim 5, characterized in that: Adjust the pH of the slurry to 6.5 ~ 8.

5.

7. The application of the composite inhibitor for the separation of calcium-containing gangue minerals in non-ferrous metals according to claim 5, characterized in that: The fatty acid collector in step (3) is sodium oleate, and the dosage is 300 g / t. The amount of compound inhibitor added in step (2) is 10 ~ 100 g / t of the dry weight of the raw ore.

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