Method for recovering zinc from copper tailings

Abstract

The invention discloses a method for recovering zinc from copper tailings, which utilizes the characteristics of zinc which is easy to sublimate from a solid state to a gaseous state at a high temperature and exists in the form of zinc steam, so that the method tries to adopt a pyrogenic process and a rotary kiln to calcine the copper tailings, and utilizes a dust collecting device to recover and cool flue gas in the rotary kiln. Zinc is efficiently recovered, and the purity of the recovered zinc is high.

Description

Technical Field

[0001] The present invention relates to the technical field of copper tailings slag treatment, and particularly to a method for recovering zinc from copper tailings slag. Background Art

[0002] Copper tailings slag refers to the final tailings slag obtained after the tailings of copper ore are smelted by pyrometallurgy and then flotation. It is mainly composed of fine powder particles remaining after the ore is crushed, smelted, and floated. Copper tailings slag cannot be directly utilized. The zinc content in copper tailings slag is about 1.5%, and this part of zinc exists on the surface layer of copper tailings slag. In traditional beneficiation methods such as magnetic separation, gravity separation, flotation, etc., zinc cannot be effectively extracted and recovered. Summary of the Invention

[0003] Therefore, based on the above background, the present invention has developed a method for recovering zinc from copper tailings slag. The present invention uses pyrometallurgy and utilizes the fact that zinc is easy to sublimate at high temperatures and exists in the form of zinc to cool and recover it, so as to recover zinc with high purity.

[0004] The technical solution provided by the present invention is as follows:

[0005] A method for recovering zinc from copper tailings slag, comprising the following steps:

[0006] 1) Mix the copper tailings slag to form a pretreatment material;

[0007] Calcine the pretreatment material in step 1) using a rotary kiln, and at the same time use a flue gas recovery device;

[0008] Ball mill the soot collected and cooled by the flue gas recovery device.

[0009] Preferably, the temperature inside the rotary kiln during calcination in step 2) is 1000 - 1200 °C.

[0010] Further, the weight ratio of the copper tailings slag to the additive is: 1:0.8.

[0011] Adopting the above technical solution, the beneficial effects are as follows:

[0012] The present invention utilizes the characteristics of zinc, which is easy to sublimate from solid state to gaseous state at high temperatures and exists in the form of zinc vapor. Therefore, the present invention attempts to use pyrometallurgy, calcine the copper tailings slag using a rotary kiln, and use a dust collection device to recover and cool the flue gas in the rotary kiln to efficiently recover zinc, and the recovered zinc has high purity. Description of the Drawings

[0013] Attached Figure 1 Spectral analysis of copper tailings slag for the example. Detailed Embodiments

[0014] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0015] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "vertical", "circumferential", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0016] In the description of the present invention, the "first feature" and "second feature" may include one or more of such features. In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0017] The technical solution of the present invention is as follows: The following questions have been answered above.

[0018] A method for recovering zinc from copper tailings slag, comprising the following steps:

[0019] 1) Stir and mix the copper tailings slag with an additive to obtain a pretreatment material

[0020] The additive of the present invention plays a reducing role and mainly includes coking coal or coal.

[0021] 2) Calcine the pretreatment material in step 1) in a rotary kiln for 30 minutes (this time can fully recover zinc. Increasing the time will increase the beneficiation cost, and reducing it will affect the recovery rate), and at the same time use a flue gas recovery device;

[0022] 3) Cool the soot collected by the flue gas recovery device.

[0023] After the rotary kiln is heated to a high temperature, zinc oxide will vaporize into steam, and the dust collecting fan will suck the gas into the condenser for cooling. When the temperature drops below 400 degrees Celsius, zinc will turn into a dust form and be recovered by the bag dust removal device, obtaining zinc concentrate with a grade of 50%.

[0024] Preferably, the temperature inside the rotary kiln during calcination in step 2) is 1000 - 1200 °C. The boiling point of zinc is 907 degrees. With the intervention of the materials, if the temperature is too low, zinc cannot be fully vaporized, and if the temperature is too high, it will cause energy waste and also affect the reduction effect of iron when recovering iron simultaneously.

[0025] Furthermore, the weight ratio of the copper tailings slag to the additive is 1:0.8.

[0026] The above description of the present invention and its embodiments is not restrictive. What is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. In general, if those of ordinary skill in the art are inspired by it and, without departing from the spirit of the present invention, design similar structural forms and embodiments to this technical solution without creative efforts, they shall fall within the protection scope of the present invention.

Claims

1. A method for recovering zinc from copper tailings slag, characterized in that, It includes the following steps: 1) Stir and mix copper tailings slag with an additive to obtain a pre-treatment material; Calcine the pre-treatment material obtained in step 1) using a rotary kiln, and at the same time collect and cool the flue gas of the rotary kiln using a flue gas recovery device; 2) Ball mill the soot collected and cooled by the flue gas recovery device.

2. The method for recovering zinc from copper tailings slag according to claim 1, wherein During the calcination in step 2), the temperature inside the rotary kiln is 1000 - 1200 °C.

3. The method for recovering zinc from copper tailings slag according to claim 1, wherein The weight ratio of the copper tailings slag to the additive is 1:0.

8.

4. The method for recovering zinc from copper tailings slag according to claim 1, wherein The calcination time in the rotary kiln in step 2) is 30 minutes.

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