A magnesium reducing agent for copper-nickel ore with high serpentine content and application thereof

Abstract

The application provides a magnesium reducing agent for copper-nickel ore with high serpentine content and application thereof, and belongs to the technical field of mineral flotation, solves the problem of low cost and small dosage in magnesium reduction of copper-nickel mixed concentrate without affecting water reuse and solid-liquid separation, and the magnesium reducing agent is a serpentine inhibitor, which is compounded by styrene-acrylic acid multi-hydroxy copolymer, styrene-acrylic acid multi-carboxy copolymer, styrene-acrylic acid multi-hydroxy copolymer salt, sodium alginate, CMC and divalent iron salt in proportion. In application, the copper-nickel raw ore or one-stage flotation tailings are ground and slurried, the serpentine inhibitor is added, then butylamine and ethyl xanthate are added and stirred, and copper-nickel concentrate is obtained through one-time roughing, cleaning and scavenging. The raw material of the agent is easy to obtain and green and environmentally friendly, the problem of difficult solid-liquid separation of traditional CMC inhibitor is solved while the magnesium reduction effect is ensured, the magnesium oxide content in the copper-nickel concentrate can be significantly reduced, and the concentrate quality is improved.

Description

Technical Field

[0001] This invention belongs to the field of mineral flotation technology, specifically relating to a magnesium-reducing agent for copper-nickel ore with high serpentine content and its application. Background Technology

[0002] Copper-nickel ore often contains large amounts of serpentine. Commonly used magnesium-reducing agents for serpentine include CMC and water glass. However, these agents have drawbacks such as difficulty in solid-liquid separation and difficulty in dilution. How to reduce magnesium in copper-nickel mixed concentrates at low cost and with low dosage without affecting water reuse and solid-liquid separation has been a long-standing research topic. The magnesium-reducing agent of this invention is mainly composed of styrene-acrylic acid polyhydroxy copolymers, styrene-acrylic acid polycarboxyl copolymers, and styrene-acrylic acid polyhydroxy copolymer salts, combined with small amounts of sodium alginate, CMC, and divalent iron salts. It features good solid-liquid separation, low cost, and significant magnesium-reducing effect. Summary of the Invention

[0003] The purpose of this invention is to provide a magnesium-reducing agent for copper-nickel ores with high serpentine content and its application, so as to solve the problem of reducing magnesium in copper-nickel mixed concentrates at low cost and in small dosage without affecting water reuse and solid-liquid separation.

[0004] The technical solution of this invention is: a magnesium-reducing agent for copper-nickel ore with high serpentine content. The magnesium-reducing agent is a serpentine inhibitor, which is composed of styrene-acrylic acid polyhydroxy copolymer, styrene-acrylic acid polycarboxyl copolymer, styrene-acrylic acid polyhydroxy copolymer salt, sodium alginate, CMC, and ferrous salt. The mass percentages of the components of the serpentine inhibitor are as follows: 10-12% styrene-acrylic acid polyhydroxy copolymer, 10-12% styrene-acrylic acid polycarboxylic acid copolymer, 40-55% styrene-acrylic acid polyhydroxy copolymer salt, 10-12% sodium alginate, 10-12% CMC, and 5-12% ferrous salt.

[0005] As a further improvement of the present invention, the ferrous salt is either ferrous sulfate or ferrous chloride.

[0006] An application of a magnesium-reducing reagent for magnesium-reducing flotation in copper-nickel ore with high serpentine content includes the following steps: Step 1: Grind the copper-nickel ore or the tailings from the first stage of flotation into a slurry; Step 2: Add serpentine inhibitor to the slurry, then add butyl ammonium and ethyl xanthate and stir well; Step 3: A roughing process is carried out to obtain a rough concentrate and scavenging tailings. The rough concentrate is then subjected to 1-4 cleaning processes to obtain copper-nickel concentrate. Serpentine inhibitors are added during the cleaning process. The scavenging process is carried out 1-3 times, and the scavenging tailings are combined into the final tailings.

[0007] As a further improvement of the present invention, in step one, the serpentine content in the copper-nickel ore or the tailings from the first stage of flotation is ≥30%.

[0008] As a further improvement of the present invention, in step two, the total amount of serpentine inhibitor used in the roughing process is 0-1000 g / t of raw ore.

[0009] As a further improvement of the present invention, in step two, the amount of butanilium used is 5-20 g / t of raw ore, and the amount of ethyl xanthate used is 20-60 g / t of raw ore.

[0010] As a further improvement of the present invention, in step three, the total amount of serpentine inhibitor used in the fine selection operation is 200-1000g / t of feed.

[0011] The beneficial effects of this invention are as follows: This invention addresses the technical challenge of reducing magnesium content in the flotation of high-serpentine copper-nickel ore. Through the synergistic compounding of multiple functional components and the optimization of the staged dosing process, a balance is achieved between the magnesium reduction and quality improvement effect and the solid-liquid separation performance.

[0012] 1. Synergistic Enhancement of Suppression Selectivity by Multifunctional Polymers: This invention uses styrene-acrylic acid polyhydroxy copolymers, polycarboxyl copolymers, and polyhydroxy copolymer salts as main agents. The functional groups of the three polymers complement each other: hydroxyl groups anchor the active hydroxyl sites on the serpentine surface through hydrogen bonding, carboxyl groups enhance the electrostatic repulsion and surface hydrophilic effect between particles, and salt components improve the dispersibility and solubility stability of the reagent in the pulp. The three components are combined to form a gradient adsorption layer, which not only ensures a strong hydrophilic inhibition effect on serpentine, but also avoids excessive flocculation that would lead to the entrainment and inhibition of valuable sulfide minerals, thereby improving the separation selectivity of the flotation process.

[0013] 2. Synthetic-Natural Compound Formula: Balancing Efficacy and Economy: This invention combines a small amount of sodium alginate and CMC, utilizing the flexible molecular chains of natural polysaccharides to fill the adsorption blind spots of synthetic polymers, further enhancing the stability of the hydrophilic film on the serpentine surface; at the same time, the low proportion of natural components avoids the problem of a significant increase in slurry viscosity caused by high dosage of CMC alone, thus controlling the overall cost of the reagents while ensuring the magnesium reduction effect.

[0014] 3. Enhanced effect of ferrous salt bridging and weakening of heterogeneous aggregation: This invention introduces ferrous salt as an ion bridging component, which enhances the adsorption strength of reagent molecules on the serpentine surface through coordination. At the same time, ferrous ions can regulate the surface potential of minerals, weaken the heterogeneous aggregation between serpentine and copper-nickel sulfide minerals, reduce the floating of gangue minerals with sulfide mineral foam, and help achieve magnesium reduction and quality improvement of concentrate.

[0015] 4. The segmented dosing system adapts to the needs of the entire flotation process: This invention adopts a segmented dosing system in which less or no reagent is added in the roughing stage and supplemented in the cleaning stage. The inhibitory effect is weakened in the roughing stage to ensure that copper-nickel sulfide minerals float fully and avoid loss of metal recovery rate. In the cleaning stage, inhibitors are added in a concentrated manner to precisely enhance the inhibitory effect of serpentine and achieve deep reduction of magnesium in the concentrate, taking into account both the metal recovery rate and the magnesium oxide content of the concentrate.

[0016] 5. Solid-liquid separation-friendly and suitable for mineral processing water reuse: Compared with traditional single CMC inhibitors, the reagent of this invention is mainly composed of low-viscosity synthetic copolymers with a low proportion of natural polysaccharide components, which will not form a high-viscosity hydration network in the slurry. Experimental verification shows that the slurry settling velocity and concentrate filtration performance are significantly better than those of the pure CMC system, and will not deteriorate the subsequent solid-liquid separation process. It is conducive to closed-loop recycling of mineral processing water and is suitable for the continuous production needs of industrial sites. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the process for processing a section of flotation tailings using the technology of the present invention in Example 1; Figure 2 This is a schematic diagram of the process for treating a stage of flotation tailings with conventional CMC reagents in Comparative Example 1. Figure 3 A schematic diagram of the process for treating a stage of flotation tailings without adding serpentine inhibitor in Comparative Example 2; Figure 4 This is a schematic diagram of the process for processing copper-nickel ore using the technology of the present invention in Example 2; Figure 5 This is a schematic diagram of the process for treating copper-nickel ore with conventional CMC reagents in Comparative Example 3. Figure 6 This is a schematic diagram of the process for treating copper-nickel ore without adding serpentine inhibitor in Comparative Example 4. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. However, the following embodiments are only for illustrative purposes, and the scope of protection of the present invention should include all the contents of the claims, not just these embodiments. For the method embodiments, for the sake of simplicity, they are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the actions and components involved are not necessarily essential to the present invention.

[0019] Example 1 The test sample was the flotation tailings from the first stage of the third mine of a copper-nickel mine in Northwest China, containing 0.38% copper, 0.13% nickel, and 31.20% serpentine.

[0020] The process of using the technical solution of this invention is as follows: Figure 1 As shown: After classifying and grinding the tailings from the first stage of flotation, the pulp is adjusted, and serpentine depressant is added. The reagent composition is 10% styrene-acrylic acid polyhydroxy copolymer, 10% styrene-acrylic acid polycarboxyl copolymer, 55% styrene-acrylic acid polyhydroxy copolymer salt, 10% sodium alginate, 10% CMC, and 5% ferrous sulfate. The amount of serpentine depressant used in the roughing stage is 0 g / t. Collector butyl ammonium 10 g / t and ethyl xanthate 40 g / t are added to the roughing stage. The rough concentrate from the roughing stage is then treated with 400 g / t of the above-mentioned serpentine depressant, followed by two cleaning stages and two scavenging stages, finally yielding copper-nickel concentrate and tailings.

[0021] Comparative Example 1 Using conventional CMC as an inhibitor, the procedure is as follows: Figure 2 As shown: Except for replacing all the points where the inhibitor of the present invention was added with the same amount of CMC, the other grinding and flotation conditions were completely consistent with those in Example 1.

[0022] Comparative Example 2 No serpentine inhibitors are added; the process is as follows: Figure 3 As shown: the remaining grinding and flotation conditions are completely consistent with those in Example 1.

[0023] The experimental results of Example 1, Comparative Example 1, and Comparative Example 2 are shown in Table 1.

[0024] Table 1 As shown in Table 1, compared with the method without inhibitors, the technology of the present invention can increase the nickel grade of the concentrate by 0.58 percentage points, the copper grade by 0.26 percentage points, and the magnesium oxide content by 1.02 percentage points. The nickel recovery rate is increased by 1.01 percentage points and the copper recovery rate is increased by 2.65 percentage points. The magnesium reduction and quality improvement effect is comparable to that of conventional CMC, but the slurry filtration speed is increased by about 30%, and the solid-liquid separation performance is significantly better than that of the CMC system.

[0025] Example 2 The test sample was the raw ore from a copper-nickel mine in Northwest China. The mineral composition is shown in Table 2, with serpentine content of 32.14%.

[0026] The process of using the technical solution of this invention is as follows: Figure 4As shown: After the raw ore is graded and ground, the pulp is adjusted. In the first roughing stage, the amount of serpentine depressant is 0 g / t, and 10 g / t of collector butylammonium and 40 g / t of ethyl xanthate are added. In the first cleaning stage, the amount of depressant is 200 g / t. After the first scavenging stage, the rough and concentrate are graded and refmilled, and then enter the second roughing stage. In the second roughing stage, 100 g / t of depressant is added, and in the second cleaning stage, 400 g / t of depressant is added. The whole process consists of 2 roughing, 2 cleaning, and 2 scavenging stages, yielding copper-nickel concentrate 1, copper-nickel concentrate 2, and the final tailings.

[0027] The composition of the inhibitor is the same as in Example 1.

[0028] Table 2 Comparative Example 3 Using conventional CMC as an inhibitor, the procedure is as follows: Figure 5 As shown: all points where the inhibitor of the present invention was added were replaced with the same amount of CMC, and the remaining grinding and flotation conditions were completely consistent with those in Example 2.

[0029] Comparative Example 4 No serpentine inhibitors are added; the process is as follows: Figure 6 As shown: the remaining grinding and flotation conditions are completely consistent with those in Example 2.

[0030] The experimental results of Example 2, Comparative Example 3, and Comparative Example 4 are shown in Table 3.

[0031] Table 3 As shown in Table 3, compared with the absence of inhibitors, the addition of the inhibitors of this invention increased the total concentrate nickel grade by 2.07 percentage points, copper grade by 1.53 percentage points, decreased magnesium oxide content by 5.63 percentage points, increased nickel recovery rate by 0.84 percentage points, and increased copper recovery rate by 1.73 percentage points. The magnesium reduction and quality improvement effect is similar to that of CMC, but the concentrate filtration moisture content is reduced by 2-3 percentage points, and the tailings settling speed is significantly improved, completely solving the industry pain points of difficult solid-liquid separation and increased return water viscosity in the CMC system.

[0032] The above experiments show that the process without inhibitors (Comparative Example 2) only involves graded grinding, collector roughing, and scavenging operations, without adding any serpentine inhibitors. The process is the shortest, but the concentrate has the highest magnesium oxide content. The conventional CMC process (Comparative Example 1) adds an equal amount of CMC at the roughing and cleaning points, and the dosing location is the same as the technology of this invention. It can achieve a certain magnesium reduction effect, but it will lead to an increase in pulp viscosity. The technology of this invention (Example 1) uses the same dosing point, replacing single CMC with a composite inhibitor. While maintaining a comparable magnesium reduction effect and recovery rate, it significantly improves the solid-liquid separation performance of the pulp.

[0033] The process without inhibitors (Comparative Example 4) is a conventional flotation process with two stages of grinding and two stages of roughing and cleaning, without the addition of serpentine inhibitors throughout the process; the conventional CMC process (Comparative Example 3) adds equal amounts of CMC at each stage of roughing and cleaning, which has a clear effect on reducing magnesium but has the inherent defect of difficulty in solid-liquid separation; the technology of the present invention (Example 2) is matched with a two-stage flotation process by adopting a staged dosing method, adjusting the amount of inhibitor according to the properties of the ore pulp in each stage, and adapting to the complex working conditions of direct flotation of raw ore.

[0034] In summary, the magnesium-reducing reagent and flotation process provided by this invention have a stable magnesium-reducing effect on both high-magnesium copper-nickel ore with a serpentine content of over 30% and primary flotation tailings. The magnesium reduction rate and metal recovery rate are comparable to those of conventional CMC inhibitors in the industry. Simultaneously, it solves the technical problems of high pulp viscosity, slow settling and filtration, and limited water reuse in traditional CMC systems. The reagent raw materials are widely available and environmentally friendly, and the dosing regime is compatible with existing concentrator processes, requiring no large-scale equipment modifications for implementation. It possesses excellent industrial application value and promising prospects for widespread adoption.

Claims

1. A magnesium-reducing agent for copper-nickel ore with high serpentine content, characterized in that: The magnesium-lowering agent is a serpentine inhibitor, composed of styrene-acrylic acid polyhydroxy copolymer, styrene-acrylic acid polycarboxyl copolymer, styrene-acrylic acid polyhydroxy copolymer salt, sodium alginate, CMC, and ferrous salt; The mass percentages of the components of the serpentine inhibitor are as follows: 10-12% styrene-acrylic acid polyhydroxy copolymer, 10-12% styrene-acrylic acid polycarboxylic acid copolymer, 40-55% styrene-acrylic acid polyhydroxy copolymer salt, 10-12% sodium alginate, 10-12% CMC, and 5-12% ferrous salt.

2. The magnesium-reducing agent for high serpentine content copper-nickel ore according to claim 1, characterized in that: The ferrous salt is either ferrous sulfate or ferrous chloride.

3. The application of the magnesium-reducing reagent for high serpentine content copper-nickel ore in magnesium-reducing flotation according to claim 1, characterized in that: Includes the following steps: Step 1: Grind the copper-nickel ore or the tailings from the first stage of flotation into a slurry; Step 2: Add serpentine inhibitor to the slurry, then add butyl ammonium and ethyl xanthate and stir well; Step 3: A roughing process is carried out to obtain a rough concentrate and scavenging tailings. The rough concentrate is then subjected to 1-4 cleaning processes to obtain copper-nickel concentrate. Serpentine inhibitors are added during the cleaning process. The scavenging process is carried out 1-3 times, and the scavenging tailings are combined into the final tailings.

4. The application of the magnesium-reducing reagent for high serpentine content copper-nickel ore in magnesium-reducing flotation according to claim 3, characterized in that: In step one, the serpentine content in the copper-nickel ore or the tailings from the first stage of flotation is ≥30%.

5. The application of the magnesium-reducing reagent for high serpentine content copper-nickel ore in magnesium-reducing flotation according to claim 3, characterized in that: In step two, the total amount of serpentine inhibitor used in the roughing process is 0-1000 g / t of raw ore.

6. The application of the magnesium-reducing reagent for high serpentine content copper-nickel ore in magnesium-reducing flotation according to claim 3, characterized in that: In step two, the dosage of ammonium butyrate is 5-20 g / t of raw ore, and the dosage of ethyl xanthate is 20-60 g / t of raw ore.

7. The application of the magnesium-reducing reagent for high serpentine content copper-nickel ore in magnesium-reducing flotation according to claim 3, characterized in that: In step three, the total amount of serpentine inhibitor used in the fine-grained operation is 200-1000g / t of feed.

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