A method for treating cyanide tailings treatment effluent

Abstract

This invention proposes a method for treating cyanide tailings waste liquid, belonging to the field of resource utilization technology. After depositing magnetic iron oxide (Fe3O4) on the surface of the waste cyanide tailings, it is coated with high specific surface area graphene oxide, treated with silane coupling agent KH560, and then co-treated with UiO-66-NH2 and COF layers. Finally, yeast protein and cyclodextrin are coupled to the surface to obtain the cyanide tailings. The cyanide tailings obtained by this invention have a large specific surface area, providing a large number of adsorption active sites, improving the pollutant mass transfer rate, facilitating separation, avoiding secondary pollution, reducing operating costs, exhibiting broad-spectrum adsorption performance, high simultaneous removal rates of heavy metal ions, cyanides, and organic pollutants, and stable structure, realizing the resource transformation of waste cyanide tailings from hazardous waste into high-value functional materials.

Description

Technical Field

[0001] This invention relates to the field of resource utilization technology, specifically to a method for treating cyanide tailings waste liquid. Background Technology

[0002] The direct waste from gold production, cyanide tailings, is utilized through flotation, with the addition of flotation reagents to obtain pyrite concentrate, which is then sold to sulfuric acid producers. These producers can then use the concentrate to produce industrial sulfuric acid, generate electricity from waste heat, and produce iron concentrate. However, the high-silica waste cyanide tailings remaining after pyrite concentrate production (containing approximately 9% sulfur, primarily silicon dioxide) lacks feasible utilization technologies and methods. It can only be temporarily stored in greenhouses, and the sheer quantity of this waste places enormous pressure on enterprises and the environment, becoming a bottleneck hindering the development of gold mining companies.

[0003] Long-term storage of high-silicon cyanide tailings not only occupies a large amount of land resources but also poses a risk of polluting surface water, groundwater, and soil. Therefore, how to treat cyanide tailings and achieve resource utilization is of profound significance.

[0004] Chinese invention patent CN111589842B discloses a method for treating and utilizing gold cyanide tailings, comprising the following steps: (1) filtering the gold cyanide tailings using a filter press to reduce the water content to below 20%; (2) preheating and dehydrating the cyanide tailings with a water content below 20% to remove some cyanide and all attached water; (3) controlling the oxidation roasting time according to the differences in the properties of the tailings after preheating and roasting; (4) cooling the cyanide-crushed tailings after oxidation roasting to obtain the final decyanated tailings product. The gold cyanide tailings treated by this invention are active and can be used as a high-quality raw material for cement plants, realizing the resource reuse of gold tailings. However, the decyanated tailings product can only be used as a raw material for cement plants and cannot further improve soil quality, etc. The resource transformation as a high-value functional material has low added value. Summary of the Invention

[0005] The purpose of this invention is to propose a method for treating cyanide tailings waste liquid. This method has a large specific surface area, providing a large number of adsorption active sites, improving the mass transfer rate of pollutants, facilitating separation, avoiding secondary pollution, reducing operating costs, and exhibiting broad-spectrum adsorption performance. It also has a high simultaneous removal rate of heavy metal ions, cyanides, and organic pollutants, and a stable structure, enabling the resource-based transformation of cyanide tailings waste from hazardous waste into high-value functional materials.

[0006] The technical solution of this invention is implemented as follows: This invention provides a method for preparing cyanide tailings. After depositing magnetic iron oxide on the surface of waste cyanide tailings, it is coated with high specific surface area graphene oxide, treated with silane coupling agent KH560, and then the surface is co-treated with UiO-66-NH2 and COF layers. Finally, yeast protein and cyclodextrin are coupled to the surface to obtain cyanide tailings.

[0007] As a further improvement to the present invention, the following steps are included: S1. The waste cyanide tailings are crushed, ground, added to water, ferric chloride and ferrous chloride are added, the pH value of the solution is adjusted under inert gas protection, heated and stirred to react, filtered, washed and dried to obtain magnetic waste cyanide tailings. S2. Add the cyanide tailings of magnetic waste to an aqueous dispersion of graphene oxide and spray dry to obtain high specific surface area graphene oxide-treated cyanide tailings of magnetic waste. S3. High specific surface area graphene oxide treated magnetic waste cyanide tailings are added to ethanol, silane coupling agent KH560 is added, the mixture is heated and stirred to react, the magnets are separated, washed, and dried to obtain KH560 cyanide tailings. S4. KH560 cyanide tailings, zirconium chloride, and 2-aminoterephthalic acid were added to a solvent and ultrasonically dispersed until uniform. A first hydrothermal reaction was performed, followed by magnetic separation. The product was added to a solvent, and benzothiophene tricarboxaldehyde and [2,2'-bipyridine]-5,5'-diamine were added. The mixture was ultrasonically dispersed until uniform. A second hydrothermal reaction was performed, followed by magnetic separation. The product was washed and dried to obtain MOF / COF cyanide tailings. S5. Add MOF / COF cyanide tailings, cyclodextrin, yeast protein, and potassium dihydrogen phosphate to water, heat and stir to react, perform hydrothermal reaction, separate with a magnet, wash, and dry to obtain cyanide tailings.

[0008] As a further improvement of the present invention, the mass ratio of the waste cyanide tailings, ferric chloride and ferrous chloride in step S1 is 15-20:3.24:1.26, the pH value of the solution is adjusted to 10-11, the temperature of the heating and stirring reaction is 80-90℃, and the time is 3-5h.

[0009] As a further improvement of the present invention, the concentration of the graphene oxide aqueous dispersion in step S2 is 5-10 mg / mL, and the solid-liquid ratio of the magnetic waste cyanide tailings and the graphene oxide aqueous dispersion is 1:3-5 g / mL.

[0010] As a further improvement of the present invention, in step S3, the mass ratio of the high specific surface area graphene oxide treated magnetic waste cyanide tailings and silane coupling agent KH560 is 100:3-5, and the heating and stirring reaction temperature is 40-50℃, and the time is 2-4h.

[0011] As a further improvement of the present invention, in step S4, the mass ratio of KH560 cyanide tailings, zirconium chloride, 2-aminoterephthalic acid, benzothiophene tricarboxaldehyde, and [2,2'-bipyridine]-5,5'-diamine is 8-10:1-1.1:0.8-1.2:0.6-1:0.5-0.8; the ultrasonic dispersion power is 300-500W and the time is 20-40min; the solvent is a mixture of N,N-dimethylformamide and acetic acid with a volume ratio of 10:1-2; the temperature of the first hydrothermal reaction is 110-130℃ and the time is 20-28h; and the temperature of the second hydrothermal reaction is 100-120℃ and the time is 70-75h.

[0012] As a further improvement of the present invention, the mass ratio of MOF / COF cyanide tailings, cyclodextrin, yeast protein, and potassium dihydrogen phosphate in step S5 is 10-15:2-3:1-2:0.15-0.2, the heating and stirring reaction temperature is 90-100℃, the time is 0.5-1.5h, and the hydrothermal reaction temperature is 140-160℃, the time is 8-10h.

[0013] The present invention further protects a cyanide tailings obtained by the above-described preparation method.

[0014] This invention further protects a method for treating the above-mentioned cyanide tailings wastewater, which involves adding the above-mentioned cyanide tailings to the wastewater, stirring and adsorbing, separating with a magnet, and discharging after testing and confirming compliance.

[0015] As a further improvement of the present invention, the amount of cyanide tailings added is 0.1-10 wt%.

[0016] The present invention has the following beneficial effects: This invention utilizes waste cyanide tailings. First, magnetic iron oxide (Fe3O4) is deposited on the surface, enabling the cyanide tailings to be magnetically separated, thus simplifying the separation process and reducing the difficulty of wastewater treatment agents. After spray drying, a layer of wrinkled graphene oxide with a high specific surface area is loaded onto the surface of the magnetic waste cyanide tailings. Due to its abundant hydroxyl groups, the graphene oxide reacts with the silane coupling agent KH560 to create epoxy groups, which then react with the amino groups of UiO-66-NH2 to fix it onto the surface of the waste cyanide tailings. Further, a COF layer is deposited on the surface, resulting in a product that synergistically combines MOF and COF structures. Furthermore, the graphene oxide encapsulates the magnetic core through π-π stacking and hydrogen bonding, and its wrinkled structure provides additional adsorption planes and can serve as a guiding template for MOF / COF growth.

[0017] This synergistic structure possesses both the regularly arranged porous channels of a COF structure, providing ample adsorption sites and promoting rapid pollutant migration, and strong covalent bonds that give the material excellent thermal stability, significantly improving adsorption performance and greatly enhancing the adsorption efficiency for heavy metal ions. Simultaneously, it incorporates the abundant metal active centers of MOF materials, significantly improving its adsorption efficiency and recognition ability for water pollutants, thus exhibiting a synergistic effect.

[0018] The hydrophobic cavity of β-cyclodextrin and its ability to form strong host-guest complexes give it good adsorption properties for organic matter and heavy metal ions, while the abundant amino and carboxyl groups on proteins also contribute to the adsorption of metal ions.

[0019] The cyanide tailings prepared by this invention have a large specific surface area, providing a large number of adsorption active sites, improving the mass transfer rate of pollutants, and are easy to separate, avoiding secondary pollution and reducing operating costs. They have broad-spectrum adsorption performance, high simultaneous removal rates of heavy metal ions, cyanides, and organic pollutants, and stable structure, realizing the resource transformation of waste cyanide tailings from hazardous waste into high-value functional materials. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 The image shows the infrared spectrum of the cyanide tailings obtained in Example 1. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1 This embodiment provides a method for preparing cyanide tailings, including the following steps: S1. 15g of cyanide tailings waste was crushed and ground for 1 hour, added to 200mL of water, 3.24g of ferric chloride and 1.26g of ferrous chloride were added, and under nitrogen protection, the pH of the solution was adjusted to 10-11, heated to 80℃, stirred and reacted for 3 hours, filtered, washed and dried to obtain magnetic cyanide tailings waste. S2. Add 10g of magnetic waste cyanide tailings to 30mL of 10mg / mL graphene oxide aqueous dispersion, spray dry, and obtain high specific surface area graphene oxide treated magnetic waste cyanide tailings. S3. Add 10g of high specific surface area graphene oxide-treated magnetic waste cyanide tailings to 200mL of ethanol, add 0.3g of silane coupling agent KH560, heat to 40℃, stir and react for 2h, separate the magnets, wash, dry, and obtain KH560 cyanide tailings. S4. Add 8g of KH560 cyanide tailings, 1g of zirconium chloride, and 0.8g of 2-aminoterephthalic acid to 1L of solvent, ultrasonically disperse at 300W for 20min, hydrothermally react at 110℃ for 20h, separate by magnet, add the product to 1L of solvent, add 0.6g of benzothiophene tricarboxaldehyde and 0.5g of [2,2'-bipyridine]-5,5'-diamine, ultrasonically disperse at 300W for 20min, hydrothermally react at 100℃ for 70h, separate by magnet, wash, and dry to obtain MOF / COF cyanide tailings; The solvent is a mixture of N,N-dimethylformamide and acetic acid in a volume ratio of 10:1; S5. Add 10g MOF / COF cyanide tailings, 2g β-cyclodextrin, 1g Saccharomyces cerevisiae protein, and 0.15g potassium dihydrogen phosphate to 200mL of water, heat to 90℃, stir and react for 0.5h, then hydrothermally react at 140℃ for 8h. Separate with a magnet, wash, and dry to obtain cyanide tailings. Figure 1 The image shows an infrared spectrum, with 445 cm⁻¹. -1 and 576cm -1 The peak at 1600 cm⁻¹ is a characteristic absorption peak of Fe₃O₄. -1 The peak at 1664 cm⁻¹ is a characteristic peak of imine bonds. -1 The peak at this point is a characteristic absorption peak of the carbonyl group, suggesting that the aldehyde functional group may remain in the composite material.

[0024] Example 2 This embodiment provides a method for preparing cyanide tailings, including the following steps: S1. 20g of waste cyanide tailings were crushed and ground for 1 hour, added to 200mL of water, 3.24g of ferric chloride and 1.26g of ferrous chloride were added, and under nitrogen protection, the pH of the solution was adjusted to 10-11, heated to 90℃, stirred and reacted for 5 hours, filtered, washed and dried to obtain magnetic waste cyanide tailings. S2. Add 10g of magnetic waste cyanide tailings to 50mL of 5mg / mL graphene oxide aqueous dispersion, spray dry, and obtain high specific surface area graphene oxide treated magnetic waste cyanide tailings. S3. Add 10g of high specific surface area graphene oxide-treated magnetic waste cyanide tailings to 200mL of ethanol, add 0.5g of silane coupling agent KH560, heat to 50℃, stir and react for 4h, separate the magnets, wash, dry, and obtain KH560 cyanide tailings. S4. 10g KH560 cyanide tailings, 1.1g zirconium chloride, and 1.2g 2-aminoterephthalic acid were added to 1L of solvent, ultrasonically dispersed at 500W for 40min, and hydrothermally reacted at 130℃ for 28h. The mixture was separated by magnetism. The product was added to 1L of solvent, along with 1g benzothiophene tricarboxaldehyde and 0.8g [2,2'-bipyridine]-5,5'-diamine. The mixture was ultrasonically dispersed at 500W for 40min, and hydrothermally reacted at 120℃ for 75h. The mixture was then separated by magnetism, washed, and dried to obtain MOF / COF cyanide tailings. The solvent is a mixture of N,N-dimethylformamide and acetic acid in a volume ratio of 10:2; S5. Add 15g MOF / COF cyanide tailings, 3g β-cyclodextrin, 2g Saccharomyces cerevisiae protein, and 0.2g potassium dihydrogen phosphate to 200mL of water, heat to 100℃, stir and react for 1.5h, then hydrothermally react at 160℃ for 10h, separate by magnet, wash, and dry to obtain cyanide tailings.

[0025] Example 3 This embodiment provides a method for preparing cyanide tailings, including the following steps: S1. 17g of waste cyanide tailings was crushed and ground for 1 hour, added to 200mL of water, 3.24g of ferric chloride and 1.26g of ferrous chloride were added, and under nitrogen protection, the pH of the solution was adjusted to 10-11, heated to 85℃, stirred and reacted for 4 hours, filtered, washed and dried to obtain magnetic waste cyanide tailings. S2. Add 10g of magnetic waste cyanide tailings to 40mL of 7mg / mL graphene oxide aqueous dispersion, spray dry, and obtain high specific surface area graphene oxide treated magnetic waste cyanide tailings. S3. Add 10g of high specific surface area graphene oxide-treated magnetic waste cyanide tailings to 200mL of ethanol, add 0.4g of silane coupling agent KH560, heat to 45℃, stir and react for 3h, separate the magnets, wash, dry, and obtain KH560 cyanide tailings. S4. 9g of KH560 cyanide tailings, 1.05g of zirconium chloride, and 1g of 2-aminoterephthalic acid were added to 1L of solvent, ultrasonically dispersed at 400W for 30min, and hydrothermally reacted at 120℃ for 24h. The mixture was separated by magnetism. The product was added to 1L of solvent, along with 0.8g of benzothiophene tricarboxaldehyde and 0.65g of [2,2'-bipyridine]-5,5'-diamine. The mixture was ultrasonically dispersed at 400W for 30min, and hydrothermally reacted at 110℃ for 72h. The mixture was then separated by magnetism, washed, and dried to obtain MOF / COF cyanide tailings. The solvent is a mixture of N,N-dimethylformamide and acetic acid in a volume ratio of 10:1.5; S5. Add 12g MOF / COF cyanide tailings, 2.5g β-cyclodextrin, 1.5g Saccharomyces cerevisiae protein, and 0.17g potassium dihydrogen phosphate to 200mL of water, heat to 95℃, stir and react for 1h, then hydrothermally react at 150℃ for 9h, separate by magnet, wash, and dry to obtain cyanide tailings.

[0026] Comparative Example 1 The difference from Example 3 is that step S2 was not performed.

[0027] Includes the following steps: S1. 17g of waste cyanide tailings was crushed and ground for 1 hour, added to 200mL of water, 3.24g of ferric chloride and 1.26g of ferrous chloride were added, and under nitrogen protection, the pH of the solution was adjusted to 10-11, heated to 85℃, stirred and reacted for 4 hours, filtered, washed and dried to obtain magnetic waste cyanide tailings. S2. Add 10g of magnetic waste cyanide tailings to 200mL of ethanol, add 0.4g of silane coupling agent KH560, heat to 45℃, stir and react for 3h, separate the magnets, wash, dry, and obtain KH560 cyanide tailings. S3. Add 9g of KH560 cyanide tailings, 1.05g of zirconium chloride, and 1g of 2-aminoterephthalic acid to 1L of solvent, ultrasonically disperse at 400W for 30min, hydrothermally react at 120℃ for 24h, separate by magnet, add the product to 1L of solvent, add 0.8g of benzothiophene tricarboxaldehyde and 0.65g of [2,2'-bipyridine]-5,5'-diamine, ultrasonically disperse at 400W for 30min, hydrothermally react at 110℃ for 72h, separate by magnet, wash, and dry to obtain MOF / COF cyanide tailings; The solvent is a mixture of N,N-dimethylformamide and acetic acid in a volume ratio of 10:1.5; S4. Add 12g MOF / COF cyanide tailings, 2.5g β-cyclodextrin, 1.5g Saccharomyces cerevisiae protein, and 0.17g potassium dihydrogen phosphate to 200mL of water, heat to 95℃, stir and react for 1h, then hydrothermally react at 150℃ for 9h, separate by magnet, wash, and dry to obtain cyanide tailings.

[0028] Comparative Example 2 The difference from Example 3 is that MOF processing was not performed in step S4.

[0029] Includes the following steps: S1. 17g of waste cyanide tailings was crushed and ground for 1 hour, added to 200mL of water, 3.24g of ferric chloride and 1.26g of ferrous chloride were added, and under nitrogen protection, the pH of the solution was adjusted to 10-11, heated to 85℃, stirred and reacted for 4 hours, filtered, washed and dried to obtain magnetic waste cyanide tailings. S2. Add 10g of magnetic waste cyanide tailings to 40mL of 7mg / mL graphene oxide aqueous dispersion, spray dry, and obtain high specific surface area graphene oxide treated magnetic waste cyanide tailings. S3. Add 10g of high specific surface area graphene oxide-treated magnetic waste cyanide tailings to 200mL of ethanol, add 0.4g of silane coupling agent KH560, heat to 45℃, stir and react for 3h, separate the magnets, wash, dry, and obtain KH560 cyanide tailings. S4. Add 9g of KH560 cyanide tailings to 1L of solvent, add 0.8g of benzothiophene tricarboxaldehyde and 0.65g of [2,2'-bipyridine]-5,5'-diamine, ultrasonically disperse at 400W for 30min, hydrothermally react at 110℃ for 72h, separate by magnet, wash, and dry to obtain COF cyanide tailings; The solvent is a mixture of N,N-dimethylformamide and acetic acid in a volume ratio of 10:1.5; S5. Add 12g COF cyanide tailings, 2.5g β-cyclodextrin, 1.5g Saccharomyces cerevisiae protein, and 0.17g potassium dihydrogen phosphate to 200mL of water, heat to 95℃, stir and react for 1h, then hydrothermally react at 150℃ for 9h, separate by magnet, wash, and dry to obtain cyanide tailings.

[0030] Comparative Example 3 The difference from Example 3 is that COF treatment was not performed in step S4.

[0031] Includes the following steps: S1. 17g of waste cyanide tailings was crushed and ground for 1 hour, added to 200mL of water, 3.24g of ferric chloride and 1.26g of ferrous chloride were added, and under nitrogen protection, the pH of the solution was adjusted to 10-11, heated to 85℃, stirred and reacted for 4 hours, filtered, washed and dried to obtain magnetic waste cyanide tailings. S2. Add 10g of magnetic waste cyanide tailings to 40mL of 7mg / mL graphene oxide aqueous dispersion, spray dry, and obtain high specific surface area graphene oxide treated magnetic waste cyanide tailings. S3. Add 10g of high specific surface area graphene oxide-treated magnetic waste cyanide tailings to 200mL of ethanol, add 0.4g of silane coupling agent KH560, heat to 45℃, stir and react for 3h, separate the magnets, wash, dry, and obtain KH560 cyanide tailings. S4. Add 9g KH560 cyanide tailings, 1.05g zirconium chloride, and 1g 2-aminoterephthalic acid to 1L of solvent, disperse by ultrasonication at 400W for 30min, hydrothermal reaction at 120℃ for 24h, separate by magnet, wash, and dry to obtain MOF cyanide tailings. The solvent is a mixture of N,N-dimethylformamide and acetic acid in a volume ratio of 10:1.5; S5. Add 12g MOF cyanide tailings, 2.5g β-cyclodextrin, 1.5g Saccharomyces cerevisiae protein, and 0.17g potassium dihydrogen phosphate to 200mL of water, heat to 95℃, stir and react for 1h, then hydrothermally react at 150℃ for 9h, separate by magnet, wash, and dry to obtain cyanide tailings.

[0032] Comparative Example 4 The difference from Example 3 is that step S4 was not performed.

[0033] Includes the following steps: S1. 17g of waste cyanide tailings was crushed and ground for 1 hour, added to 200mL of water, 3.24g of ferric chloride and 1.26g of ferrous chloride were added, and under nitrogen protection, the pH of the solution was adjusted to 10-11, heated to 85℃, stirred and reacted for 4 hours, filtered, washed and dried to obtain magnetic waste cyanide tailings. S2. Add 10g of magnetic waste cyanide tailings to 40mL of 7mg / mL graphene oxide aqueous dispersion, spray dry, and obtain high specific surface area graphene oxide treated magnetic waste cyanide tailings. S3. Add 10g of high specific surface area graphene oxide-treated magnetic waste cyanide tailings to 200mL of ethanol, add 0.4g of silane coupling agent KH560, heat to 45℃, stir and react for 3h, separate the magnets, wash, dry, and obtain KH560 cyanide tailings. S4. Add 12g KH560 cyanide tailings, 2.5g β-cyclodextrin, 1.5g Saccharomyces cerevisiae protein, and 0.17g potassium dihydrogen phosphate to 200mL of water, heat to 95℃, stir and react for 1h, then hydrothermally react at 150℃ for 9h, separate by magnet, wash, and dry to obtain cyanide tailings.

[0034] Comparative Example 5 The difference from Example 3 is that step S5 was not performed.

[0035] Includes the following steps: S1. 17g of waste cyanide tailings was crushed and ground for 1 hour, added to 200mL of water, 3.24g of ferric chloride and 1.26g of ferrous chloride were added, and under nitrogen protection, the pH of the solution was adjusted to 10-11, heated to 85℃, stirred and reacted for 4 hours, filtered, washed and dried to obtain magnetic waste cyanide tailings. S2. Add 10g of magnetic waste cyanide tailings to 40mL of 7mg / mL graphene oxide aqueous dispersion, spray dry, and obtain high specific surface area graphene oxide treated magnetic waste cyanide tailings. S3. Add 10g of high specific surface area graphene oxide-treated magnetic waste cyanide tailings to 200mL of ethanol, add 0.4g of silane coupling agent KH560, heat to 45℃, stir and react for 3h, separate the magnets, wash, dry, and obtain KH560 cyanide tailings. S4. Add 9g of KH560 cyanide tailings, 1.05g of zirconium chloride, and 1g of 2-aminoterephthalic acid to 1L of solvent, ultrasonically disperse at 400W for 30min, hydrothermally react at 120℃ for 24h, separate by magnet, add the product to 1L of solvent, add 0.8g of benzothiophene tricarboxaldehyde and 0.65g of [2,2'-bipyridine]-5,5'-diamine, ultrasonically disperse at 400W for 30min, hydrothermally react at 110℃ for 72h, separate by magnet, wash, and dry to obtain MOF / COF cyanide tailings, which is the cyanide tailings; The solvent is a mixture of N,N-dimethylformamide and acetic acid in a volume ratio of 10:1.5.

[0036] Test Example 1 The specific surface area of ​​the cyanide tailings prepared in Examples 1-3 and Comparative Examples 1-5 was determined using a 3-FLEX 3500 multi-station high-throughput gas adsorption analyzer. Compressive strength was tested using an LJ 5000 compression testing machine with a range of 0-5000 N. The results are shown in Table 1.

[0037] Table 1

[0038] As can be seen from the table above, the cyanide tailings obtained in Examples 1-3 of this invention have a large specific surface area and high compressive strength.

[0039] Test Example 2: Purification Effect on Antibiotic Wastewater Configuration 10 -4 A mol / L cephalexin solution was used as antibiotic wastewater. The pH of the wastewater was adjusted to 7 using 0.1 mol / L hydrochloric acid and 0.01 mol / L sodium hydroxide. 100 mL of cephalexin solution was taken and cyanide tailings prepared in Examples 1-3 and Comparative Examples 1-5 were added at a rate of 1 wt%. The mixture was stirred at 300 rpm for 5 min to ensure thorough mixing of the cyanide tailings and wastewater. The cyanide tailings were separated by magnetism, and the supernatant was collected. The absorption peak of the solution at 262 nm was detected using a UV-Vis spectrophotometer. The scavenging effect of the cyanide tailings on cephalexin was calculated, and the results are shown in Table 2.

[0040] Table 2

[0041] As shown in the table above, the cyanide tailings obtained in Examples 1-3 of this invention have a high removal rate of cephalexin.

[0042] Test Example 3 The cyanide tailings prepared in Examples 1-3 and Comparative Examples 1-5 of this invention were used to treat a wastewater with severely excessive heavy metals. The amount added was 2wt%. After the treatment process, the effluent was discharged, and the various indicators are shown in Table 3.

[0043] Table 3

[0044] As can be seen from the table above, the cyanide tailings prepared in Examples 1-3 of this invention have a high removal rate of heavy metal ions.

[0045] 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 method for preparing cyanide tailings, characterized in that, After depositing magnetic iron oxide on the surface of cyanide tailings, it is coated with high specific surface area graphene oxide, treated with silane coupling agent KH560, and then the surface is co-treated with UiO-66-NH2 and COF layers. Finally, yeast protein and cyclodextrin are coupled to the surface to obtain cyanide tailings.

2. The preparation method according to claim 1, characterized in that, Includes the following steps: S1. The waste cyanide tailings are crushed, ground, added to water, ferric chloride and ferrous chloride are added, the pH value of the solution is adjusted under inert gas protection, heated and stirred to react, filtered, washed and dried to obtain magnetic waste cyanide tailings. S2. Add the cyanide tailings of magnetic waste to an aqueous dispersion of graphene oxide and spray dry to obtain high specific surface area graphene oxide-treated cyanide tailings of magnetic waste. S3. High specific surface area graphene oxide treated magnetic waste cyanide tailings are added to ethanol, silane coupling agent KH560 is added, the mixture is heated and stirred to react, the magnets are separated, washed, and dried to obtain KH560 cyanide tailings. S4. KH560 cyanide tailings, zirconium chloride, and 2-aminoterephthalic acid were added to a solvent and ultrasonically dispersed until uniform. A first hydrothermal reaction was performed, followed by magnetic separation. The product was added to a solvent, and benzothiophene tricarboxaldehyde and [2,2'-bipyridine]-5,5'-diamine were added. The mixture was ultrasonically dispersed until uniform. A second hydrothermal reaction was performed, followed by magnetic separation. The product was washed and dried to obtain MOF / COF cyanide tailings. S5. Add MOF / COF cyanide tailings, cyclodextrin, yeast protein, and potassium dihydrogen phosphate to water, heat and stir to react, perform hydrothermal reaction, separate with a magnet, wash, and dry to obtain cyanide tailings.

3. The preparation method according to claim 2, characterized in that, The mass ratio of the waste cyanide tailings, ferric chloride, and ferrous chloride mentioned in step S1 is 15-20: 3.24:1.26, wherein the pH value of the adjusted solution is 10-11, and the temperature of the heating and stirring reaction is 80-90℃, and the time is 3-5h.

4. The preparation method according to claim 2, characterized in that, The concentration of the graphene oxide aqueous dispersion in step S2 is 5-10 mg / mL, and the solid-liquid ratio of the magnetic waste cyanide tailings and the graphene oxide aqueous dispersion is 1:3-5 g / mL.

5. The preparation method according to claim 2, characterized in that, In step S3, the mass ratio of the high specific surface area graphene oxide-treated magnetic waste cyanide tailings to the silane coupling agent KH560 is 100:3-5, and the heating and stirring reaction temperature is 40-50℃ for 2-4 hours.

6. The preparation method according to claim 2, characterized in that, In step S4, the mass ratio of KH560 cyanide tailings, zirconium chloride, 2-aminoterephthalic acid, benzothiophene tricarboxaldehyde, and [2,2'-bipyridine]-5,5'-diamine is 8-10:1-1.1:0.8-1.2:0.6-1:0.5-0.

8. The ultrasonic dispersion power is 300-500W, and the time is 20-40 min. The solvent is a mixture of N,N-dimethylformamide and acetic acid, with a volume ratio of 10:1-2. The temperature of the first hydrothermal reaction is 110-130℃, and the time is 20-28 h. The temperature of the second hydrothermal reaction is 100-120℃, and the time is 70-75 h.

7. The preparation method according to claim 2, characterized in that, In step S5, the mass ratio of MOF / COF cyanide tailings, cyclodextrin, yeast protein, and potassium dihydrogen phosphate is 10-15:2-3:1-2:0.15-0.

2. The heating and stirring reaction is carried out at a temperature of 90-100℃ for 0.5-1.5 hours, and the hydrothermal reaction is carried out at a temperature of 140-160℃ for 8-10 hours.

8. A cyanide tailings obtained by the preparation method according to any one of claims 1-7.

9. A method for treating cyanide tailings waste liquid as described in claim 8, characterized in that, The cyanide tailings as described in claim 8 are added to the wastewater, stirred and adsorbed, separated by magnets, and discharged after the test shows that the standard is met.

10. The method according to claim 9, characterized in that, The amount of cyanide tailings added is 0.1-10 wt%.

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