A method for deep purification of a solution using smelting waste residues

Abstract

The present application relates to a kind of methods for deep purification solution with smelting waste residue, belong to industrial wastewater treatment technical field.The present application carries out microwave vacuum sintering pretreatment to zinc leaching waste residue and obtains pretreated zinc leaching waste residue;Pretreated zinc leaching waste residue is added to arsenic-containing solution, and ultrasonic intensification reaction is carried out for 0.5-5h, solid-liquid separation is carried out, and purified solution and arsenic-containing solid residue are obtained.The present application uses zinc leaching waste residue containing zinc sulfide to purify arsenic-containing solution and remove arsenic, uses the technical means of "waste treatment", does not introduce impurity ions to the system, and can avoid increasing the burden of smelting system.

Description

Technical Field

[0001] This invention relates to a method for deep purification of solutions using smelting waste residue, belonging to the field of industrial wastewater treatment technology. Background Technology

[0002] Arsenic is widely found in mineral resources such as copper, lead, and zinc, with 70% of the world's proven arsenic reserves concentrated in my country. In non-ferrous smelting processes, most of the arsenic in arsenic-containing sulfide concentrates enters the sulfur dioxide flue gas. Some arsenic is removed by gravity or electrostatic dust removal, while the remaining arsenic is removed during flue gas scrubbing and purification processes before acid production, accumulating in the acidic wastewater, thus forming waste acid. Waste acid is characterized by high arsenic content, high acidity, and complex composition. Currently, methods for removing arsenic from smelting waste acid mainly include lime-iron salt precipitation, sulfide precipitation, adsorption, and membrane separation. Among these, the lime-iron salt method is currently the most widely used, and iron salts are also common and widely used arsenic removal agents in smelting waste acid. Compared to other arsenic removal agents, iron salts have advantages such as high arsenic removal efficiency and simple operation, but also disadvantages such as high processing costs and high energy consumption.

[0003] Currently, over 85% of the world's zinc is produced through hydrometallurgical zinc refining. The process mainly involves roasting zinc concentrate to form zinc calcinate, followed by neutral and two acidic leaching processes. The leachate is then purified and electrolytically deposited into zinc ingots. Acid leaching produces a large amount of zinc leaching residue, which is the primary waste generated in zinc smelting. Producing 1 ton of metallic zinc generates approximately 0.85-1.2 tons of leaching residue. The large amount of residue generated by hydrometallurgical zinc refining, if not properly treated, can severely pollute the environment and waste resources. The smelting process also produces large amounts of wastewater containing arsenic and heavy metals, which requires purification before discharge or reuse. Otherwise, it will harm the survival of plants and animals and severely disrupt the ecological balance. Therefore, how to achieve comprehensive utilization of zinc leaching residue and treat arsenic-containing solutions is a crucial issue facing the zinc smelting industry. Summary of the Invention

[0004] To address the issues of comprehensive utilization of zinc leaching residue and purification of arsenic-containing solutions, this invention proposes a method for deep purification of solutions using smelting waste residue. This invention uses high-temperature zinc leaching waste residue pretreated with microwave vacuum sintering as an arsenic removal agent. Zinc in the zinc leaching waste residue mainly exists in the phases of zinc ferrite (ZnO·Fe2O3), zinc sulfide (ZnS), zinc sulfate (ZnSO4), and zinc oxide (ZnO). Microwave vacuum sintering pretreatment induces microcrack propagation and fracture in the minerals, thereby altering the microstructure and properties of the zinc leaching residue. The high-temperature zinc leaching waste residue is then added to the arsenic-containing solution, where it dissolves rapidly under ultrasonic enhancement, generating arsenic... 2-Arsenic sulfide precipitates are formed by combining with arsenic ions. Without ultrasonic enhancement, due to the complexity of zinc leaching residue, the resulting arsenic sulfide precipitates tend to coat the surface of the zinc leaching residue, leading to a slower arsenic precipitation rate and slower dissolution of high-temperature zinc leaching waste. Under ultrasonic enhancement, ultrasound generates a large number of small bubbles when it acts on the liquid. When the cavitation bubbles collapse, they generate a powerful shock wave. Under the action of the shock wave, the inclusions in the zinc leaching residue are opened, mass and heat transfer is increased, and arsenic sulfide precipitates are prevented from coating the surface of the zinc leaching residue. At the same time, it promotes the dissolution of insoluble and slightly soluble sulfides in the zinc leaching residue.

[0005] A method for deep purification of solution using smelting waste residue, the specific steps of which are as follows:

[0006] (1) Pretreated zinc leaching waste residue is obtained by microwave vacuum sintering pretreatment;

[0007] (2) The pretreated zinc leaching waste residue was directly added to the arsenic-containing solution, and the reaction was enhanced by ultrasound for 0.5~5h. The solid and liquid were separated to obtain the purified solution and the arsenic-containing solid residue.

[0008] The temperature of the microwave vacuum sintering pretreatment in step (1) is 100-800℃ and the time is 60-120min.

[0009] The ZnS content in the zinc leaching waste residue in step (1) is 15-26% by mass percentage.

[0010] The acidity of the arsenic-containing solution in step (2) is 80~120 g / L.

[0011] The arsenic content in the arsenic-containing solution in step (2) is 50-20000 mg / L.

[0012] Step (2) The solid-liquid ratio (g:mL) of the pretreated zinc leaching waste residue and arsenic-containing solution is 1:5~1:25.

[0013] The ultrasonic power in step (2) is 50~1200W.

[0014] The beneficial effects of this invention are:

[0015] (1) This invention uses microwave vacuum sintering pretreatment to induce microcrack propagation and fracture in the minerals, thereby altering the microstructure and properties of the zinc leaching residue; the high-temperature zinc leaching waste residue is added to an arsenic-containing solution, where it rapidly dissolves under ultrasonic enhancement, promoting the dissolution of sparingly soluble and slightly soluble sulfides in the zinc leaching residue, and generating S 2- It combines with arsenic ions to form arsenic sulfide precipitate residue, and avoids the arsenic sulfide precipitate residue coating the surface of zinc leaching residue;

[0016] (2) The present invention uses zinc leaching waste containing zinc sulfide to purify and remove arsenic from arsenic-containing solutions. It adopts the technical means of "using waste to treat waste" and does not introduce impurity ions into the system, thus avoiding increasing the burden on the smelting system. Furthermore, the zinc in the zinc leaching waste enters the purification solution, increasing the concentration of zinc ions in the solution, which facilitates zinc electrowinning of the solution in the later stage and improves the zinc recovery rate. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0018] Example 1: The main components of the zinc leaching waste residue in this example are shown in Table 1 below;

[0019] Table 1. Main components of zinc leaching waste (wt.%)

[0020] Zinc oxide Zinc sulfide Zinc sulfate Iron compounds copper compounds 36.8 24 30.5 6 2.7

[0021] A method for deep purification of solution using smelting waste residue, the specific steps of which are as follows:

[0022] (1) The zinc leaching waste residue was pretreated by microwave vacuum sintering at 400℃ for 120 min to obtain pretreated zinc leaching waste residue;

[0023] (2) The pretreated zinc leaching waste residue was added to an arsenic-containing solution with an acidity of 120 g / L and an arsenic content of 1000 mg / L. The reaction was ultrasonically enhanced for 3 h under stirring conditions at a temperature of 25 °C. Solid-liquid separation was performed to obtain a purified solution and an arsenic-containing solid residue. The solid-liquid ratio of the pretreated zinc leaching waste residue to the arsenic-containing solution was 1:5 g:mL. The ultrasonic frequency was 20 kHz, the ultrasonic power was 100 W, and the stirring speed was 350 r / min.

[0024] The arsenic content in the purified solution was 3.1 mg / L, as determined by inductively coupled plasma atomic emission spectrometry (ICP-AES), and the arsenic removal rate in the arsenic-containing wastewater was 99.69%.

[0025] Example 2: The main components of the zinc leaching waste residue in this example are shown in Table 2 below;

[0026] Table 2. Main components of zinc leaching waste (wt.%)

[0027] Zinc oxide Zinc sulfide Zinc sulfate Lead compounds copper compounds 29.8 20 25.5 16 8.7

[0028] A method for deep purification of solution using smelting waste residue, the specific steps of which are as follows:

[0029] (1) The zinc leaching waste residue was pretreated by microwave vacuum sintering at 300℃ for 100 min to obtain pretreated zinc leaching waste residue;

[0030] (2) The pretreated zinc leaching waste residue was added to an arsenic-containing solution with an acidity of 100 g / L and an arsenic content of 963 mg / L. The reaction was ultrasonically enhanced for 2.5 h under stirring conditions at a temperature of 35 °C. Solid-liquid separation was performed to obtain a purified solution and an arsenic-containing solid residue. The solid-liquid ratio of the pretreated zinc leaching waste residue to the arsenic-containing solution was 1:10 g:mL. The ultrasonic frequency was 18 kHz, the ultrasonic power was 80 W, and the stirring rate was 300 r / min.

[0031] The arsenic content in the purified solution was 92.3 mg / L, as determined by inductively coupled plasma atomic emission spectrometry (ICP-AES), and the arsenic removal rate in the arsenic-containing wastewater was 90.42%.

[0032] Example 3: The main components of the zinc leaching waste residue in this example are shown in Table 3 below;

[0033] Table 3. Main components of zinc leaching waste residue (wt.%)

[0034] Zinc oxide Zinc sulfide Zinc sulfate Zinc ferrite Iron compounds 16.5 25 15.5 30 13

[0035] A method for deep purification of solution using smelting waste residue, the specific steps of which are as follows:

[0036] (1) Zinc leaching waste residue was pretreated by microwave vacuum sintering at 600℃ for 60 min to obtain pretreated zinc leaching waste residue;

[0037] (2) The pretreated zinc leaching waste residue was added to an arsenic-containing solution with an acidity of 80 g / L and an arsenic content of 1245 mg / L. The reaction was ultrasonically enhanced at a temperature of 45℃ and under stirring conditions for 4 h. Solid-liquid separation was performed to obtain a purified solution and an arsenic-containing solid residue. The solid-liquid ratio of the pretreated zinc leaching waste residue to the arsenic-containing solution was 1:15 g:mL. The ultrasonic frequency was 22 kHz, the ultrasonic power was 180 W, and the stirring rate was 400 r / min.

[0038] The arsenic content in the purified solution was 143.40 mg / L, as determined by inductively coupled plasma atomic emission spectrometry (ICP-AES), and the arsenic removal rate in the arsenic-containing wastewater was 88.48%.

[0039] Example 4: The main components of the zinc leaching waste residue in this example are shown in Table 4 below;

[0040] Table 4. Main components of zinc leaching waste (wt.%)

[0041] Zinc ferrite Zinc sulfide Zinc sulfate Iron compounds copper compounds 24.8 23 11.8 29.9 10.5

[0042] A method for deep purification of solution using smelting waste residue, the specific steps of which are as follows:

[0043] (1) The zinc leaching waste residue was pretreated by microwave vacuum sintering at 800℃ for 80 min to obtain pretreated zinc leaching waste residue;

[0044] (2) The pretreated zinc leaching waste residue was added to an arsenic-containing solution with an acidity of 110 g / L and an arsenic content of 1500 mg / L. The reaction was ultrasonically enhanced for 2 h under stirring conditions at 20 °C. Solid-liquid separation was performed to obtain a purified solution and an arsenic-containing solid residue. The solid-liquid ratio of the pretreated zinc leaching waste residue to the arsenic-containing solution was 1:20 g:mL. The ultrasonic frequency was 19 kHz, the ultrasonic power was 150 W, and the stirring rate was 320 r / min.

[0045] The arsenic content in the purified solution was 264.8 mg / L, as determined by inductively coupled plasma atomic emission spectrometry (ICP-AES), and the arsenic removal rate in the arsenic-containing wastewater was 82.35%.

[0046] Example 5: The main components of the zinc leaching waste residue in this example are shown in Table 5 below;

[0047] Table 5. Main components of zinc leaching waste (wt.%)

[0048] Zinc oxide Zinc sulfide Zinc sulfate Zinc ferrite Lead compounds 27.3 15 19.9 31.8 6

[0049] A method for deep purification of solution using smelting waste residue, the specific steps of which are as follows:

[0050] (1) The zinc leaching waste residue was pretreated by microwave vacuum sintering at 100℃ for 60 min to obtain pretreated zinc leaching waste residue;

[0051] (2) The pretreated zinc leaching waste residue was added to an arsenic-containing solution with an acidity of 90 g / L and an arsenic content of 500 mg / L. The reaction was ultrasonically enhanced for 5 h under stirring conditions at a temperature of 20 °C. Solid-liquid separation was performed to obtain a purified solution and an arsenic-containing solid residue. The solid-liquid ratio of the pretreated zinc leaching waste residue to the arsenic-containing solution was 1:25 g:mL. The ultrasonic frequency was 21 kHz, the ultrasonic power was 50 W, and the stirring rate was 250 r / min.

[0052] The arsenic content in the purified solution was 138.4 mg / L, as determined by inductively coupled plasma atomic emission spectrometry (ICP-AES), and the arsenic removal rate in the arsenic-containing wastewater was 72.32%.

[0053] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for deep purification of a solution using smelting waste residue, characterized in that, The specific steps are as follows: (1) Pretreated zinc leaching waste residue is obtained by microwave vacuum sintering pretreatment; the content of ZnS in the zinc leaching waste residue is 15-26wt.%, the temperature of microwave vacuum sintering pretreatment is 100-800℃, and the time is 60-120min. (2) Add the pretreated zinc leaching waste residue to the arsenic-containing solution, and perform ultrasonic-enhanced reaction for 0.5~5h. Separate the solid and liquid to obtain the purified solution and arsenic-containing solid residue.

2. The method for deep purification of solution using smelting waste slag according to claim 1, characterized in that: Step (2) The arsenic content in the arsenic-containing solution is 50-20000 mg / L.

3. The method for deep purification of solution using smelting waste slag according to claim 1, characterized in that: Step (2) The solid-liquid ratio (g:mL) of the pretreated zinc leaching waste residue and arsenic-containing solution is 1:5~1:

25.

4. The method for deep purification of solution using smelting waste slag according to claim 1, characterized in that: Step (2) The ultrasonic power is 50~1200W.