Inhibitor for flotation separation of copper-zinc sulfide ore and preparation method of inhibitor

Abstract

The invention provides a flotation separation inhibitor for copper-zinc sulfide ore, and relates to the technical field of preparation of inhibitors through mineral flotation. The inhibitor is prepared from the following raw materials: sodium zincate, maleic anhydride modified starch, an acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, tea polyphenol, vanillin and modified xanthan gum. The raw materials of the inhibitor can achieve a synergistic effect, the complexing efficiency of the inhibitor and metal ions can be improved, and the situation that Cu < 2 + > released by chalcopyrite in the flotation separation process activates sphalerite, so that the action effect is affected is avoided; the inhibitor can form an obvious selective adsorption effect on the surface of sphalerite to form a uniform and stable hydrophilic film, flotation of sphalerite is effectively inhibited, impurities introduced into copper concentrate are effectively reduced, more zinc minerals are reserved in flotation copper tailings, the grade and the recovery rate of copper in the copper concentrate are improved, and the flotation effect of sphalerite is improved. And the flotation separation effect of the copper-zinc sulfide ore is improved.

Description

Technical Field

[0001] This invention relates to the field of mineral flotation separation inhibitor technology, and particularly to an inhibitor for the flotation separation of copper-zinc sulfide ores and its preparation method. Background Technology

[0002] Copper and zinc are important metallic raw materials, widely used in high-tech fields such as metallurgy, construction, electronics, and electrical engineering. Copper-zinc sulfide ores are common mineral resources and important sources for extracting copper and zinc. Flotation is an important method for recovering copper-zinc sulfide ores. However, common copper-zinc sulfide ores often exhibit similar floatability, dense coexistence of crystals, and fine particle size. Copper ions (Cu²⁺) present in the ore grinding or slurry are easily adsorbed onto the surface of sphalerite, "activating" it and making its surface properties very similar to chalcopyrite, making conventional flotation difficult to separate them effectively. In traditional flotation processes, inorganic depressants such as cyanide and sodium sulfide are commonly used to separate copper and zinc. However, cyanide is highly toxic, and sodium sulfide produces harmful substances that endanger the health of operators and the environment during use. Furthermore, their inhibitory effect on sphalerite is limited, making it difficult to effectively activate zinc minerals, resulting in low copper and zinc recovery efficiency. In addition, while organic depressants such as polyacrylamide and tannins have been developed, they still suffer from poor selectivity, affecting the flotation production of copper-zinc sulfide ores. Therefore, there is a need to find a flotation separation depressant for copper-zinc sulfide ores to improve the efficiency of their separation and recovery. Summary of the Invention

[0003] In view of this, the present invention proposes a flotation separation inhibitor for copper-zinc sulfide ores and its preparation method.

[0004] The technical solution of this invention is implemented as follows: A flotation separation inhibitor for copper-zinc sulfide ores comprises the following heavy feedstocks: sodium zincate, maleic anhydride-modified starch, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, tea polyphenols, vanillin, and modified xanthan gum.

[0005] Preferably, the inhibitor comprises the following raw materials in parts by weight: 5-7 parts sodium zincate, 15-19 parts maleic anhydride modified starch, 9-13 parts acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, 10-14 parts tea polyphenols, 6-9 parts vanillin, and 8-11 parts modified xanthan gum.

[0006] Preferably, the inhibitor comprises the following raw materials in parts by weight: 5 parts sodium zincate, 18 parts maleic anhydride modified starch, 10 parts acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, 14 parts tea polyphenols, 8 parts vanillin, and 10 parts modified xanthan gum.

[0007] Preferably, the preparation method of the maleic anhydride modified starch is as follows: starch is dispersed in an ethanol solution, then maleic anhydride and p-toluenesulfonic acid are added, stirred and mixed, heated and reacted, filtered, washed with ethanol, dried, and pulverized to obtain maleic anhydride modified starch.

[0008] Preferably, the starch is selected from one or more of corn starch, potato starch, and tapioca starch.

[0009] Preferably, the concentration of the ethanol solution is 70-80% v / v; the mass ratio of starch, ethanol solution, maleic anhydride, and p-toluenesulfonic acid is 1:4-6:0.3-0.5:0.01-0.03.

[0010] Preferably, the heating reaction involves raising the temperature to 60-70°C and reacting for 4-6 hours.

[0011] Preferably, the modified xanthan gum is prepared by: adding xanthan gum to water and stirring to form a xanthan gum solution; adjusting the pH of the xanthan gum solution to 8-10 with sodium hydroxide solution; adding sodium hypochlorite solution with a mass concentration of 6-8 w / v% while stirring at 30-40℃; stirring and reacting for 1-2 hours after the addition is complete; then adding sodium sulfite and stirring for 10-15 minutes; adjusting the pH to 6.5-7.5 with hydrochloric acid; and then concentrating under reduced pressure and drying to obtain modified xanthan gum.

[0012] Preferably, the xanthan gum solution concentration is 4-5 w / v; the mass ratio of xanthan gum solution, sodium hypochlorite solution, and sodium sulfite is 10-12:2-3:4-5; the sodium hydroxide solution concentration is 0.1-0.2 mol / L; the hydrochloric acid concentration is 0.1-0.2 mol / L; and the sodium sulfite concentration is 0.1-0.3 mol / L.

[0013] The method for preparing a flotation separation inhibitor for copper-zinc sulfide ores includes the following steps: mixing sodium zincate, maleic anhydride-modified starch, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, tea polyphenols, vanillin, and modified xanthan gum to obtain the target inhibitor.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. The inhibitor of the present invention, using sodium zincate, maleic anhydride-modified starch, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, tea polyphenols, vanillin, and modified xanthan gum as raw materials, can play a synergistic role, improve the complexation ability of the inhibitor with metal ions, and prevent the release of Cu from chalcopyrite during flotation separation. 2+The activation of sphalerite affects the effect of the action. Furthermore, the inhibitor of the present invention can form a significant selective adsorption effect on the surface of sphalerite, forming a uniform and stable hydrophilic film, effectively inhibiting the flotation of sphalerite, effectively reducing the introduction of impurities into the copper concentrate, allowing more zinc minerals to be retained in the copper tailings, improving the grade and recovery rate of copper in the copper concentrate, and improving the flotation separation effect of copper-zinc sulfide ores.

[0015] 2. In this invention, starch can be modified with a suitable maleic anhydride process to introduce more carboxyl groups into the starch, enhance the selective hydrophilic adsorption of the modified starch on the surface of sphalerite, and form a stable hydrophilic layer with other raw materials. This can effectively expand the floatability difference between sphalerite and chalcopyrite in copper-zinc sulfide ores, so as to effectively separate sphalerite and chalcopyrite and improve the separation effect.

[0016] 3. In this invention, modifying xanthan gum with sodium hypochlorite can enhance its adsorption and film-forming effect, strengthen its film-forming adsorption effect on sphalerite, and also hinder the adsorption of collectors, thus avoiding the influence of the hydrophobicity of chalcopyrite. Detailed Implementation

[0017] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention.

[0018] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0019] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0020] Example 1 The depressant for flotation separation of copper-zinc sulfide ores comprises the following raw materials in parts by weight: 5 parts sodium zincate, 18 parts maleic anhydride modified starch, 10 parts acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, 14 parts tea polyphenols, 8 parts vanillin, and 10 parts modified xanthan gum.

[0021] The preparation method of maleic anhydride modified starch is as follows: starch composed of corn starch and potato starch in a mass ratio of 1:1 is dispersed in an ethanol solution with a concentration of 70% v / v. Then, maleic anhydride and p-toluenesulfonic acid are added, stirred and mixed, and the mixture is heated to 60℃ and reacted for 6 hours. After filtration, the starch is washed with ethanol, dried, and pulverized to obtain maleic anhydride modified starch. The mass ratio of starch, ethanol solution, maleic anhydride, and p-toluenesulfonic acid is 1:4:0.5:0.02.

[0022] The preparation process of modified xanthan gum is as follows: xanthan gum is added to water and stirred to form a xanthan gum solution with a concentration of 5 w / v%. The pH of the xanthan gum solution is adjusted to 10 with a concentration of 0.1 mol / L sodium hydroxide solution. Sodium hypochlorite solution with a mass concentration of 7 w / v is added dropwise while stirring at 40℃. After the addition is completed, the mixture is stirred and reacted for 1.5 h. Then, sodium sulfite with a concentration of 0.2 mol / L is added and stirred for 10 min. The pH is adjusted to 7.0 with a concentration of 0.1 mol / L hydrochloric acid. The mixture is then concentrated under reduced pressure and dried to obtain modified xanthan gum.

[0023] The method for preparing a flotation separation inhibitor for copper-zinc sulfide ores includes the following steps: mixing sodium zincate, maleic anhydride-modified starch, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, tea polyphenols, vanillin, and modified xanthan gum to obtain the target inhibitor.

[0024] Example 2 The depressant for flotation separation of copper-zinc sulfide ores comprises the following raw materials in parts by weight: 7 parts sodium zincate, 15 parts maleic anhydride modified starch, 13 parts acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, 12 parts tea polyphenols, 9 parts vanillin, and 8 parts modified xanthan gum.

[0025] The preparation method of maleic anhydride modified starch is as follows: starch composed of potato starch and cassava starch in a mass ratio of 1:2 is dispersed in an ethanol solution with a concentration of 75% v / v. Then, maleic anhydride and p-toluenesulfonic acid are added, stirred and mixed, and the mixture is heated to 70℃ and reacted for 5 hours. After filtration, the starch is washed with ethanol, dried, and pulverized to obtain maleic anhydride modified starch. The mass ratio of starch, ethanol solution, maleic anhydride, and p-toluenesulfonic acid is 1:6:0.3:0.01.

[0026] The preparation process of modified xanthan gum is as follows: xanthan gum is added to water and stirred to form a xanthan gum solution with a concentration of 4 w / v%. The pH of the xanthan gum solution is adjusted to 9 with a concentration of 0.2 mol / L sodium hydroxide solution. Sodium hypochlorite solution with a mass concentration of 6 w / v is added dropwise while stirring at 30℃. After the addition is completed, the mixture is stirred for another 2 hours. Then, sodium sulfite with a concentration of 0.1 mol / L is added and stirred for 15 minutes. The pH is adjusted to 7.5 with a concentration of 0.2 mol / L hydrochloric acid. The mixture is then concentrated under reduced pressure and dried to obtain modified xanthan gum.

[0027] The method for preparing a flotation separation inhibitor for copper-zinc sulfide ores includes the following steps: mixing sodium zincate, maleic anhydride-modified starch, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, tea polyphenols, vanillin, and modified xanthan gum to obtain the target inhibitor.

[0028] Example 3 The depressant for flotation separation of copper-zinc sulfide ores comprises the following raw materials in parts by weight: 6 parts sodium zincate, 19 parts maleic anhydride modified starch, 9 parts acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, 10 parts tea polyphenols, 6 parts vanillin, and 11 parts modified xanthan gum.

[0029] The preparation method of maleic anhydride modified starch is as follows: corn starch is dispersed in an 80% v / v ethanol solution, then maleic anhydride and p-toluenesulfonic acid are added, stirred and mixed, and then heated to 650℃ for 4 hours. After filtration, the starch is washed with ethanol, dried, and pulverized to obtain maleic anhydride modified starch. The mass ratio of starch, ethanol solution, maleic anhydride and p-toluenesulfonic acid is 1:5:0.4:0.03.

[0030] The preparation process of modified xanthan gum is as follows: xanthan gum is added to water and stirred to form a xanthan gum solution with a concentration of 5 w / v%. The pH of the xanthan gum solution is adjusted to 8 with a concentration of 0.1 mol / L sodium hydroxide solution. Under the condition of 40℃, a sodium hypochlorite solution with a mass concentration of 8 w / v is added dropwise while stirring. After the addition is completed, the mixture is stirred for 1 hour. Then, a sodium sulfite solution with a concentration of 0.3 mol / L is added and stirred for 12 minutes. The pH is adjusted to 6.5 with a concentration of 0.1 mol / L hydrochloric acid. The mixture is then concentrated under reduced pressure and dried to obtain modified xanthan gum.

[0031] The method for preparing a flotation separation inhibitor for copper-zinc sulfide ores includes the following steps: mixing sodium zincate, maleic anhydride-modified starch, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, tea polyphenols, vanillin, and modified xanthan gum to obtain the target inhibitor.

[0032] Comparative Example 1 Compared with Example 1, this comparative example changed the ratio of the raw materials of the inhibitor, while the rest remained unchanged.

[0033] This comparative example is used as a flotation separation inhibitor for copper-zinc sulfide ores and includes the following raw materials in parts by weight: 18 parts sodium zincate, 9 parts maleic anhydride modified starch, 10 parts acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, 9 parts tea polyphenols, 15 parts vanillin, and 4 parts modified xanthan gum.

[0034] Comparative Example 2 Compared with Example 1, the inhibitor in this comparative example does not contain maleic anhydride-modified starch, and the rest remains unchanged.

[0035] This comparative example is used as a flotation separation inhibitor for copper-zinc sulfide ores and includes the following raw materials in parts by weight: 5 parts sodium zincate, 10 parts acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, 14 parts tea polyphenols, 8 parts vanillin, and 10 parts modified xanthan gum.

[0036] Comparative Example 3 Compared with Example 1, the inhibitor in this comparative example does not contain acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, and the rest remains unchanged.

[0037] This comparative example is used as a flotation separation inhibitor for copper-zinc sulfide ores and includes the following raw materials in parts by weight: 5 parts sodium zincate, 18 parts maleic anhydride modified starch, 14 parts tea polyphenols, 8 parts vanillin, and 10 parts modified xanthan gum.

[0038] Comparative Example 4 Compared with Example 1, the inhibitor in this comparative example does not contain tea polyphenols, and the rest remains unchanged.

[0039] This comparative example is used as a flotation separation inhibitor for copper-zinc sulfide ores and includes the following raw materials in parts by weight: 5 parts sodium zincate, 18 parts maleic anhydride modified starch, 10 parts acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, 8 parts vanillin, and 10 parts modified xanthan gum.

[0040] Comparative Example 5 Compared with Example 1, the inhibitor in this comparative example does not contain modified xanthan gum, and the rest remains unchanged.

[0041] This comparative example is used as a flotation separation inhibitor for copper-zinc sulfide ores and includes the following raw materials in parts by weight: 5 parts sodium zincate, 18 parts maleic anhydride modified starch, 10 parts acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, 14 parts tea polyphenols, and 8 parts vanillin.

[0042] The inhibitors prepared in Examples 1-3 and Comparative Examples 1-5 were used in the flotation separation of copper-zinc sulfide ores, and the specific process is as follows: The raw ore used in the experiment had a copper grade of 0.57% and a zinc grade of 2.08%. The copper-bearing mineral was mainly chalcopyrite, and the zinc-bearing mineral was mainly sphalerite. The raw ore was crushed and ground to a powder with a thickness of -0.074 mm (80%). The powder was then adjusted to a slurry with a mass concentration of 40% and a pH of 10. The slurry was subjected to a closed-circuit flotation test consisting of one roughing, two scavenging, and three cleaning stages. The middlings were returned to the next stage in sequence. In the first roughing process, 300 g / t of inhibitor, 25 g / t of butyl xanthate, and 12 g / t of pine oil were added, stirred for 3 minutes, and then floated for 8 minutes. In the first scavenging process, 15 g / t of butyl xanthate and 6 g / t of pine oil were added, stirred for 2 minutes, and then floated for 5 minutes. In the second scavenging process, 5 g / t of butyl xanthate and 1 g / t of pine oil were added, stirred for 2 minutes, and then floated for 3 minutes. In the first cleaning process, 250 g / t of inhibitor was added, stirred for 3 minutes, and then floated for 5 minutes. In the second cleaning process, 200 g / t of inhibitor was added, stirred for 2 minutes, and then floated for 3 minutes. In the third cleaning process, 150 g / t of inhibitor was added, stirred for 2 minutes, and then floated for 3 minutes.

[0043] After flotation separation of copper-zinc sulfide ore according to the above process, copper concentrate and copper tailings were obtained. The yields of copper concentrate and copper tailings were calculated, and the copper grade and recovery rate in the copper concentrate and the zinc grade and recovery rate in the copper tailings were determined. The results are shown in Table 1 below.

[0044] Table 1. Flotation Separation Indicators for Copper-Zinc Sulfide Ores

[0045] The above results indicate that the inhibitors in Examples 1-3 of this invention can effectively selectively inhibit zinc minerals in the flotation separation process of copper-zinc sulfide ores, reducing impurities in the concentrate, allowing more zinc minerals to remain in the copper tailings, and improving the grade and recovery rate of copper in the copper concentrate. Furthermore, the zinc content in the copper concentrate is also significantly reduced, effectively separating copper and zinc. The zinc grade in the copper concentrate of Examples 1-3 is between 0.56% and 0.73%, which meets the requirements of the relevant provisions in the non-ferrous metals industry standard (YS / T318-2007). Compared with Example 1, Comparative Example 1, by changing the raw material ratio of the inhibitor, affected the flotation separation effect, indicating that an appropriate raw material ratio of inhibitor can have a synergistic effect to improve the flotation separation effect. Compared to Example 1, the inhibitor in Comparative Example 2, which did not contain maleic anhydride-modified starch, resulted in a decrease in copper grade and recovery rate in copper concentrate. This indicates that a suitable modification process with maleic anhydride can introduce more carboxyl groups into starch, enhancing the selective hydrophilic adsorption of modified starch on sphalerite and forming a stable hydrophilic layer with other raw materials, thus effectively separating sphalerite and chalcopyrite and improving the separation effect. Compared to Example 1, the inhibitors in Comparative Example 3 and Comparative Example 4, which did not contain acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer and tea polyphenols, both affected the separation effect, indicating that the acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer and tea polyphenols in the raw materials can improve the adsorption effect of the inhibitor on sphalerite. Compared with Example 1, the inhibitor in Comparative Example 5 did not contain modified xanthan gum, resulting in a poorer flotation separation effect. This indicates that modifying xanthan gum with sodium hypochlorite can enhance its adsorption and film-forming effect, strengthen its film-forming adsorption effect on sphalerite, and also hinder the adsorption of collectors, thus avoiding the influence of the hydrophobicity of chalcopyrite.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A depressant for flotation separation of copper-zinc sulfide ores, characterized in that, It includes the following raw materials: sodium zincate, maleic anhydride modified starch, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, tea polyphenols, vanillin, and modified xanthan gum.

2. The depressant for flotation separation of copper-zinc sulfide ores according to claim 1, characterized in that, The inhibitor comprises the following raw materials in parts by weight: 5-7 parts sodium zincate, 15-19 parts maleic anhydride modified starch, 9-13 parts acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, 10-14 parts tea polyphenols, 6-9 parts vanillin, and 8-11 parts modified xanthan gum.

3. The depressant for flotation separation of copper-zinc sulfide ores according to claim 1, characterized in that, The inhibitor comprises the following raw materials in parts by weight: 5 parts sodium zincate, 18 parts maleic anhydride modified starch, 10 parts acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, 14 parts tea polyphenols, 8 parts vanillin, and 10 parts modified xanthan gum.

4. The depressant for flotation separation of copper-zinc sulfide ores according to claim 1, characterized in that, The preparation method of the maleic anhydride modified starch is as follows: starch is dispersed in an ethanol solution, then maleic anhydride and p-toluenesulfonic acid are added, stirred and mixed, heated and reacted, filtered, washed with ethanol, dried, and pulverized to obtain maleic anhydride modified starch.

5. The depressant for flotation separation of copper-zinc sulfide ores according to claim 4, characterized in that, The starch is selected from one or more of corn starch, potato starch, and cassava starch.

6. The depressant for flotation separation of copper-zinc sulfide ores according to claim 4, characterized in that, The concentration of the ethanol solution is 70-80% v / v; the mass ratio of starch, ethanol solution, maleic anhydride, and p-toluenesulfonic acid is 1:4-6:0.3-0.5:0.01-0.

03.

7. The depressant for flotation separation of copper-zinc sulfide ores according to claim 4, characterized in that, The heating reaction involves raising the temperature to 60-70℃ and reacting for 4-6 hours.

8. The depressant for flotation separation of copper-zinc sulfide ores according to claim 1, characterized in that, The modified xanthan gum is prepared as follows: xanthan gum is added to water and stirred to form a xanthan gum solution. The pH of the xanthan gum solution is adjusted to 8-10 with sodium hydroxide solution. Sodium hypochlorite solution with a mass concentration of 6-8 w / v% is added dropwise while stirring at 30-40℃. After the addition is complete, the mixture is stirred for 1-2 hours. Then sodium sulfite is added and stirred for 10-15 minutes. The pH is adjusted to 6.5-7.5 with hydrochloric acid. The mixture is then concentrated under reduced pressure and dried to obtain modified xanthan gum.

9. The depressant for flotation separation of copper-zinc sulfide ores according to claim 8, characterized in that, The xanthan gum solution concentration is 4-5 w / v; the mass ratio of xanthan gum solution, sodium hypochlorite solution, and sodium sulfite is 10-12:2-3:4-5; the sodium hydroxide solution concentration is 0.1-0.2 mol / L; the hydrochloric acid concentration is 0.1-0.2 mol / L; and the sodium sulfite concentration is 0.1-0.3 mol / L.

10. The method for preparing the depressant for flotation separation of copper-zinc sulfide ores according to any one of claims 1-9, characterized in that, The process includes the following steps: mixing sodium zincate, maleic anhydride-modified starch, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, tea polyphenols, vanillin, and modified xanthan gum to obtain the target inhibitor.

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