Copper smelting slag dressing tailing-based thallium removal agent and preparation method thereof

Abstract

The invention provides a copper smelting slag separation tailing-based thallium removal agent and a preparation method thereof, and the copper smelting slag separation tailing-based thallium removal agent is prepared by taking a copper smelting slag separation tailing matrix and ferrocyanide as raw materials through pretreatment, functional modification and aftertreatment. Researches show that the perferrocyanide (Prussian blue and analogues thereof) shows extremely high selectivity and adsorption capacity on monovalent cations such as Tl < + > and Cs < + >. The cubic lattice structure provides channels with matched sizes, so that the ions can be specifically captured. The solid theoretical and technical basis is provided for efficient thallium removal by modifying the solid waste through ferrocyanide.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of metallurgical chemical industry, and particularly relates to a copper smelting slag tailing-based thallium removal agent and a preparation method thereof. BACKGROUND

[0002] Thallium (Tl) is a highly toxic heavy metal element, and thallium-containing wastewater mainly comes from non-ferrous metal smelting, thermal power generation, cement production, and steel smelting industries.

[0003] Current methods for treating thallium-containing wastewater mainly include chemical precipitation, adsorption, ion exchange, and membrane separation methods. However, these methods have obvious limitations in practical application. Traditional adsorbents (such as activated carbon) have poor selectivity and low adsorption capacity for thallium; ion exchange resins have high cost and weak anti-pollution ability; and the chemical precipitation method has poor removal effect on low-concentration thallium.

[0004] A large amount of smelting slag is generated during the copper smelting process, and these slags usually contain valuable metals such as copper, iron, and zinc. Currently, the resource utilization of copper smelting slag mainly focuses on the recovery of valuable metals. However, most existing technologies focus on the recovery of valuable metals, and there is a relative lack of research on high-value-added full utilization of smelting slag, especially the exploration of converting smelting slag into environmental functional materials is more limited.

[0005] Therefore, it is necessary to develop a method that can solve the above technical problems. SUMMARY

[0006] In view of the deficiencies in the prior art, the purpose of the present application is to provide a low-cost, high-efficiency, and high-selectivity thallium removal agent and a preparation method thereof, to realize high-value-added resource utilization of copper smelting slag tailings, and to develop a simple and easy-to-industrialize preparation method, ultimately achieving the environmental governance goal of "waste treatment with waste".

[0007] The first purpose of the present application is to provide a copper smelting slag tailing-based thallium removal agent; the second purpose is to provide a preparation method of the copper smelting slag tailing-based thallium removal agent.

[0008] The first purpose of the present application is achieved by using copper smelting slag tailing-based body and ferrocyanide as raw materials, and preparing the copper smelting slag tailing-based thallium removal agent through pretreatment, functional modification, and post-treatment.

[0009] The second purpose of the present application is achieved by including the pretreatment, functional modification, and post-treatment steps, which specifically include: A. Pretreatment: 1) After crushing and grinding, the copper smelting slag tailings with a formula ratio are ground to obtain material a; 2) Stir the material a with the acid cleaning solution for 40-80 min, then wash with water until neutral, and dry to obtain material b; 3) Place the material b in a muffle furnace to calcine to obtain material c; B, functional modification: immerse the material c in a copper salt solution under ultrasonic conditions for 1-3 h, then add a formula-matched potassium ferrocyanide solution, stir for 2-6 h to obtain material d; C, post-treatment: filter and wash the material d to remove unreacted ions, and dry under an inert atmosphere to obtain the target product, a copper smelting slag tailings-based thallium removal agent.

[0010] The specific operation is as follows: 1. Raw material pretreatment: Dry and finely grind the copper smelting slag tailings; perform acid cleaning treatment on the finely ground tailings to remove surface impurities and soluble components; the acid cleaning solution is dilute sulfuric acid or hydrochloric acid with a concentration of 0.1-1 mol / L; after acid cleaning, wash to neutral and dry at 100-150°C for 2-6 hours; place the dried tailings in a muffle furnace for calcination, with a calcination temperature of 500-750°C and a time of 1-4 hours.

[0011] 2. Ferrocyanide functional modification: Prepare a copper salt solution, wherein the copper salt is copper sulfate, copper chloride or copper nitrate, and the concentration of the copper salt solution is 0.5 mol / L-1 mol / L; immerse the pretreated tailings in the copper salt solution under ultrasonic assistance for 1-3 hours; slowly add a 0.5 mol / L-1 mol / L potassium ferrocyanide solution and slowly stir for 2-6 hours.

[0012] 3. Post-treatment: After the reaction is complete, filter and wash to remove unreacted ions; dry at 80-120°C under inert gas (such as nitrogen or argon) protection to obtain the final thallium removal agent product.

[0013] 3.2.3 Application method of thallium removal agent The application also provides an application method of the above-mentioned thallium removal agent in treating thallium-containing wastewater, comprising the following steps: 1. Add the thallium removal agent to the thallium-containing wastewater at a certain dosage (usually 0.1-5 g / L); 2. Adjust the pH value of the wastewater to 6-9 and stir at room temperature for 30-120 minutes; 3. Remove the thallium-loaded thallium removal agent by standing precipitation, filtration or magnetic separation; 4. The used thallium removal agent can be regenerated by acid washing and used again.

[0014] The application research shows that the ferri cyanide (Prussian blue and its analogues) has a high affinity for Tl+ , Cs + , and other monovalent cations exhibit extremely high selectivity and adsorption capacity. Their cubic lattice structure provides size-matched channels that can specifically capture these ions. For example, ferrocyanide loaded on modified diatomite, mesoporous silica, or hydrogel can still maintain high removal efficiency for target ions in complex water bodies (such as seawater, groundwater), and exhibit a wider applicable pH range, faster adsorption kinetics, and higher stability. This provides a solid theoretical and technical foundation for the present application to use ferrocyanide to modify solid waste to achieve efficient thallium removal. At the same time, the current copper smelting slag flotation method is most widely used, and after grinding and flotation of smelting slag, the tailings produced belong to microns and particles, and contain a lot of micron-sized silica and Fe3O4 particles, which are excellent carrier materials, and Fe3O4 itself has magnetism, which can be simply separated from the treated water, which provides a natural advantage for directly using the tailings as a thallium removal matrix.

[0015] Existing thallium removal agents generally have problems such as high cost, poor selectivity, and secondary pollution. At the same time, a large amount of copper smelting slag tailings not only occupies land, but also poses an environmental risk. Therefore, developing a thallium removal agent that uses copper smelting slag tailings as raw material, has low cost and high efficiency, not only conforms to the resource utilization of solid waste, but also provides new technology for thallium-containing wastewater treatment, and has important scientific value and practical significance. The present application learns from the experience of successfully loading ferrocyanide on other carriers and applies it to this special matrix of copper smelting slag tailings, which is a potential innovative direction.

[0016] The efficient and selective removal of thallium ions (Tl + ) by the thallium removal agent described in the present application is mainly due to the synergistic effect of the following multiple mechanisms: 1. Ion exchange dominant mechanism This is the main mechanism by which the thallium removal agent of the present application removes thallium ions. In the lattice structure of ferrocyanide (taking K2CuFe(CN)6 as an example), K + located at the corners of the cube has a relatively weak binding force with the lattice framework, and can undergo an equivalent ion exchange reaction with Tl + ions in the solution to achieve thallium ion removal.

[0017] 2. Lattice size sieving effect The cubic lattice structure of ferrocyanide has a specific size of channel window. The hydrated ion radius of Tl + , Cs + , and other ions is smaller than the size of the channel, so it can easily lose part of the hydration layer and diffuse into the interior of the lattice, and be captured by specific sites. Common coexisting ions such as Na + , Ca 2+ , and Mg 2+The hydrated ion radius of Tl is large, which is difficult to enter the crystal lattice, thereby realizing high selectivity of Tl + .

[0018] 3、Surface coordination and physical adsorption There are a large number of unsaturated coordination sites, surface hydroxyl groups and other active sites on the surface of ferrocyanide nanoparticles and the copper smelting slag tailing matrix itself, which can adsorb Tl + through electrostatic attraction and surface coordination. The rich pore structure formed after the activation of the tailing matrix also provides a place for the physical adsorption of Tl + , and accelerates the migration rate of ions to the active sites.

[0019] 4、Synergistic enhancement effect The activated tailing matrix with high porosity and high specific surface area provides a stable support and dispersed carrier for nanoscale ferrocyanide, prevents its agglomeration, fully exposes the active sites, and ensures the mechanical strength of the material. The highly dispersed ferrocyanide is the core for removing Tl + , and its unique crystal structure and chemical properties endow the material with extremely high adsorption selectivity and capacity.

[0020] Advantages of the present application: The present application successfully converts the copper smelting slag tailings into a high-efficiency thallium removal agent through ferrocyanide functionalization modification, and has many advantages: 1、Environmental benefits 1) Solid waste resourceization: a large amount of copper smelting slag tailings stored in stockpiles are converted into valuable environmental functional materials, reducing the occupation of land and environmental risks by solid waste; 2) Water pollution control: provides an efficient and economical thallium-containing wastewater treatment technology, which helps to control thallium pollution in the water environment; 2、Economic benefits 1) Low raw material cost: the main raw material is solid waste, which has very low cost, only 10-20% of the cost of traditional thallium removal materials; 2) Excellent treatment effect: high thallium removal efficiency, which can deeply purify to below 10 μg / L, reducing the subsequent treatment cost; 3) Low operating cost: simple preparation process and low energy consumption, without the need for expensive equipment investment. DETAILED DESCRIPTION

[0021] The present application will be further described below in conjunction with examples, but in no way limits the present application, any transformation or replacement based on the teaching of the present application belongs to the protection scope of the present application.

[0022] The copper smelting slag tailings-based thallium removal agent is prepared from a copper smelting slag tailings-based body and ferrocyanide through pretreatment, functional modification and post-treatment.

[0023] The mass ratio of the copper smelting slag tailings-based body to the ferrocyanide is (50-85):(15-50).

[0024] The ferrocyanide is potassium ferrocyanide.

[0025] The preparation method of the copper smelting slag tailings-based thallium removal agent comprises the steps of pretreatment, functional modification and post-treatment, and specifically comprises the following steps: A, pretreatment: 1) the copper smelting slag tailings of a formula ratio are crushed and finely ground to obtain material a; 2) the material a is stirred and cleaned with an acid washing solution for 40-80 min, then washed with water to neutral, and dried to obtain material b; 3) the material b is placed in a muffle furnace for calcination to obtain material c; B, functional modification: the material c is immersed in a copper salt solution under ultrasonic conditions for 1-3 h, then a formula ratio of potassium ferrocyanide solution is added, and stirred and reacted for 2-6 h to obtain material d; C, post-treatment: the material d is filtered and washed to remove unreacted ions, and dried in an inert atmosphere to obtain the target copper smelting slag tailings-based thallium removal agent.

[0026] The acid washing solution in step 2) of A is dilute sulfuric acid or dilute hydrochloric acid.

[0027] The concentration of the acid washing solution is 0.1-1 mol / L.

[0028] The drying in step 2) of A is drying at a temperature of 100-150 DEG C for 2-6 h.

[0029] The calcination temperature in step 3) of A is 500-750 DEG C, and the time is 1-4 h.

[0030] The copper salt solution in step B is a copper sulfate solution, a copper chloride solution or a copper nitrate solution, and the concentration is 0.5-1 mol / L.

[0031] The drying in step C is drying at 80-120 DEG C.

[0032] The following further illustrates the application with specific implementation cases: Example 1

[0033] Raw materials: The copper smelting slag tailings (from a certain copper smelting plant) mainly comprise:

[0034] Copper sulfate (analytical pure); Potassium ferrocyanide (analytical pure).

[0035] Preparation steps: 1. After crushing 80 g of copper smelting slag tailings, grind them with a ball mill; 2. Cleanse with 0.5 mol / L dilute sulfuric acid solution at 60°C for 1 hour, then wash with water until neutral, and dry at 110°C for 4 hours; 3. Place the dried tailings in a muffle furnace and activate roasting at 650°C for 2 hours; 4. Prepare a 0.5 mol / L copper sulfate solution.

[0036] 5. Add the calcined tailings to 400 ml of copper sulfate solution and ultrasonic immersion for 2 hours; 6. Slowly add 400 ml of 0.5 mol / L potassium ferrocyanide solution and slowly stir for 4 hours; 7. After the reaction is complete, filter, wash with deionized water 3 times, and dry at 100°C for 6 hours under nitrogen protection to obtain the final thallium removal agent product.

[0037] Example 2

[0038] Thallium removal performance test The thallium removal agent prepared in Example 1 was used to treat simulated thallium-containing wastewater to test its thallium removal performance.

[0039] Test method: 1. Prepare simulated wastewater with an initial thallium concentration of 100 μg / L; 2. Add 200 mL of simulated wastewater and 0.1 g of thallium removal agent (dosing amount 0.5 g / L) to a 250 mL conical flask; 3. Stir at 150 rpm at 25°C for 120 min; 4. Take a sample and filter, and measure the residual thallium concentration in the filtrate by ICP-MS.

[0040] Test results: Residual thallium concentration: 2.3 μg / L; Removal rate: 97.7%.

[0041] Example 3

[0042] Selectivity test The thallium removal agent prepared in Example 1 was tested for its selective adsorption performance on thallium in the presence of various coexisting ions.

[0043] Test conditions: Simulated wastewater composition: Tl + 100 μg / L, Ca 2+ 100 mg / L, Mg 2+ 50 mg / L, Na + 200 mg / L, K + 20 mg / L; thallium removal agent dosage 0.5 g / L, reaction time 120 minutes.

[0044] Test results: Residual thallium concentration: 3 μg / L; Removal rate: 97%.

[0045] Comparative Example 1 Thallium removal performance of unmodified tailings To illustrate the effect of functional modification, the thallium removal performance of copper smelting slag tailings that were not modified was tested.

[0046] Test conditions: The same test conditions as in Example 2 were used; The adsorbent was tailings that had only been pretreated but not subjected to ferrocyanide modification.

[0047] Test results: Residual thallium concentration: 94 μg / L; Removal rate: 6%.

Claims

1. A thallium removal agent based on copper smelting slag tailings, characterized in that, The copper smelting slag tailings-based thallium removal agent is prepared from copper smelting slag tailings matrix and ferrocyanide as raw materials through pretreatment, functionalization modification and posttreatment.

2. The thallium removal agent based on copper smelting slag tailings according to claim 1, characterized in that, The mass ratio of the copper smelting slag tailings matrix to ferrocyanide is (50~85):(15~50).

3. The thallium removal agent based on copper smelting slag tailings according to claim 1 or 2, characterized in that, The ferrocyanide mentioned is potassium ferrocyanide.

4. A method for preparing a thallium removal agent based on copper smelting slag tailings as described in any one of claims 1 to 3, characterized in that, It includes preprocessing, functionalization, and post-processing steps, specifically including: A. Pre-processing: 1) The copper smelting slag tailings of the formula are crushed and ground to obtain material a; 2) Wash material a with pickling solution for 40-80 minutes, then wash with water until neutral, and dry to obtain material b; 3) Material b is placed in a muffle furnace and calcined to obtain material c; B. Functional modification: Material c is immersed in copper salt solution and immersed under ultrasonic conditions for 1-3 hours. Then, potassium ferrocyanide solution with the formula ratio is added and stirred for 2-6 hours to obtain material d. C. Post-processing: Material d is filtered and washed to remove unreacted ions, and then dried under an inert atmosphere to obtain the target product, copper smelting slag tailings-based thallium removal agent.

5. The preparation method according to claim 4, characterized in that, The pickling solution mentioned in step 2) is dilute sulfuric acid or dilute hydrochloric acid.

6. The preparation method according to claim 4 or 5, characterized in that, The concentration of the pickling solution is 0.1~1 mol / L.

7. The preparation method according to claim 4, characterized in that, The drying described in step 2) is performed at a temperature of 100~150℃ for 2~6 hours.

8. The preparation method according to claim 4, characterized in that, The calcination temperature described in step 3) is 500~750℃, and the time is 1~4h.

9. The preparation method according to claim 4, characterized in that, The copper salt solution mentioned in step B is a copper sulfate solution, a copper chloride solution, or a copper nitrate solution, with a concentration of 0.5~1 mol / L.

10. The preparation method according to claim 4, characterized in that, The drying process described in step C is performed at 80~120℃.

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