Resource recycling method of quartz vein type lead-zinc mine tailings

Abstract

The invention discloses a resource recycling method of tailings of a quartz vein type lead-zinc mine, which comprises the following steps: grinding the tailings to-0.074 mm, putting the tailings, water and sodium hydroxide into a reaction kettle for heating and leaching at the leaching temperature of 220 DEG C, the reaction time of 120 minutes, the alkali residue mass ratio of 2: 1 and the liquid-solid ratio of 5: 1, carrying out solid-liquid separation to obtain leached residues and leached liquid, and recycling the leached residues and the leached liquid to obtain the quartz vein type lead-zinc mine tailings. And adding a certain amount of electrolyte sodium sulfate into the leachate, dropwise adding a prepared sulfuric acid solution at a certain stirring rate, controlling the pH value of the reaction endpoint, aging for a period of time at a constant temperature after the reaction is completed, filtering and repeatedly washing after the aging is completed, and finally drying a filter cake to obtain hydrated silicon dioxide, namely a white carbon black product. The product can meet the product requirements of the highest class A in the national standard GB / T10722. The technology of heating alkaline leaching and sulfuric acid precipitation is adopted, the technological process is short, the leaching rate of silicon dioxide is high, and a high-quality white carbon black product is obtained, so that recycling and reduction of a lead-zinc mine are achieved, and the development direction is pointed out for processing and utilization of high-silicon solid waste.

Description

Technical Field

[0001] This invention belongs to the field of comprehensive utilization technology of mines, specifically relating to a method for the resource recovery and utilization of tailings from quartz vein type lead-zinc mines. Background Technology

[0002] Large quantities of tailings are inevitably generated during ore mining and beneficiation. These tailings account for a very high proportion of industrial solid waste in my country and are the primary source of pollution in areas surrounding mines. Simultaneously, some older tailings are rich in mineral resources, forming new artificial mineral deposits over long periods of accumulation. Statistics show that the total amount of tailings clearly measured in my country has reached over 200 million tons, but the comprehensive utilization rate is less than 36%. The massive stockpiling and abandonment of tailings poses a threat to the health of residents around mines and represents a waste of resources. The resource utilization of lead-zinc tailings is of great significance to my country's efforts in combating pollution and reducing its dependence on imported lead-zinc mineral resources. In recent years, the country has increased its emphasis on the recovery and utilization of mineral resources. With the gradual improvement of beneficiation technology, the content of valuable elements in tailings from beneficiation plants is decreasing, further highlighting the limitations of tailings reprocessing. Therefore, developing a product that can solve the above-mentioned technical problems is essential. Summary of the Invention

[0003] The purpose of this invention is to provide a method for the resource recovery and utilization of tailings from quartz vein-type lead-zinc mines.

[0004] The objective of this invention is achieved by the resource recovery and utilization method for tailings from quartz vein-type lead-zinc mines, which includes pretreatment, leaching, and main reaction steps, specifically including: A. Pretreatment: Grind the tailings of the quartz vein-type lead-zinc ore to be treated to -0.074mm to obtain material a; B. Leaching: Water and sodium hydroxide are added to material a and placed in a reaction vessel for heating and leaching. After solid-liquid separation, leachate b and leachate residue c are obtained. C. Main reaction: Add sodium sulfate electrolyte to leachate b, and add 8-12% sulfuric acid solution dropwise in a constant temperature water bath at 70-90℃ for 1-2 hours. Control the pH at the end of the reaction to be 6.5-7.5. After the reaction is completed, age the product at a constant temperature of 70-90℃ for 1.5-2.5 hours. Separate the solid and liquid, wash the obtained solid repeatedly with water, and dry it to obtain hydrated silica.

[0005] The specific steps are as follows: 1. First, grind 100g of tailings to 100% -0.074mm, wash with water 3 times to remove the flotation reagents on its surface; 2. The tailings, water and sodium hydroxide are placed in a reaction vessel for heated leaching at a temperature of 220℃ for 120 min. The ratio of alkali residue to solid residue is 2:1 and the ratio of liquid to solid is 5:1. After cooling to room temperature, the leaching residue and leaching solution are obtained after solid-liquid separation. 3. Take 100ml of the leachate and put it in a beaker. Place the beaker in a constant temperature water bath with the temperature set. Add a certain amount of electrolyte sodium sulfate to it and add the prepared sulfuric acid solution dropwise at a certain stirring rate. Control the pH of the reaction endpoint to be 7. 4. The reaction time is 1-2 hours. After the reaction is completed, the mixture is aged at a constant temperature for 2 hours. After aging, the solid and liquid are separated. 5. The solid is repeatedly washed with water, and finally dried in an oven at 100°C to obtain hydrated silica, i.e., white carbon black.

[0006] For quartz vein-type lead-zinc ore, the tailings after recovering lead-zinc minerals by flotation contain a large amount of silicate minerals. Reprocessing and utilizing the tailings not only reduces the cost of material preparation and creates economic benefits, but also helps mines reduce the volume of tailings ponds. At the same time, it fixes heavy metal ions in the tailings to prevent secondary pollution, which is in line with the sustainable development strategy.

[0007] Resource utilization of lead-zinc mine tailings involves transforming tailings into products with specific functions through certain technological means, thereby realizing the resource recovery of tailings. Currently, the resource utilization of lead-zinc mines mainly focuses on the preparation of building materials such as cement, bricks, geopolymers, and ceramsite, as well as the recovery of valuable components and the production of functional materials such as microcrystalline glass, thermal insulation materials, and silica.

[0008] Silica, also known as hydrated silica, is a novel material composed of irregularly stacked silicon dioxide tetrahedra and water. Silicon atoms are the central atoms in the overall structure of silica. The disordered arrangement of silicon atoms and the varying distances between the hydroxyl groups connected to them result in a large specific surface area, giving silica high industrial value and promising applications. Furthermore, over 60% of the tailings from quartz vein lead-zinc mines are silica; using it as a raw material to produce silica can reduce costs and simultaneously achieve the goal of "turning waste into treasure."

[0009] This invention employs a heated alkaline leaching and sulfuric acid precipitation process, which has a short process flow and a high silica leaching rate, resulting in high-quality silica products. This enables the resource utilization and waste reduction of lead-zinc mines, and points the way for the processing and utilization of high-silicon solid waste. Detailed Implementation

[0010] The present invention will be further described below with reference to embodiments, but this is not intended to limit the present invention in any way. Any modifications or substitutions made based on the teachings of the present invention shall fall within the protection scope of the present invention.

[0011] The resource recovery and utilization method for tailings from quartz vein-type lead-zinc mines according to the present invention includes pretreatment, leaching, and main reaction steps, specifically including: A. Pretreatment: Grind the tailings of the quartz vein-type lead-zinc ore to be treated to -0.074mm to obtain material a; B. Leaching: Water and sodium hydroxide are added to material a and placed in a reaction vessel for heating and leaching. After solid-liquid separation, leachate b and leachate residue c are obtained. C. Main reaction: Add sodium sulfate electrolyte to leachate b, and add 8-12% sulfuric acid solution dropwise in a constant temperature water bath at 70-90℃ for 1-2 hours. Control the pH at the end of the reaction to be 6.5-7.5. After the reaction is completed, age the product at a constant temperature of 70-90℃ for 1.5-2.5 hours. Separate the solid and liquid, wash the obtained solid repeatedly with water, and dry it to obtain hydrated silica.

[0012] Step A also includes washing material a with water 2 to 4 times to remove flotation reagents from its surface.

[0013] The leaching temperature in step B is 210~230℃.

[0014] The leaching time in step B is 100-150 minutes.

[0015] In step C, the amount of sodium sulfate electrolyte added is 2-4% of the mass percentage of the leachate.

[0016] In step C, the volume percentage concentration of the sulfuric acid solution is 8-12%.

[0017] In step C, drying is carried out in an oven at 90~110℃.

[0018] The invention will be further illustrated below with specific implementation examples: Example 1 Take 100g of tailings (65% silica content) from a quartz vein-type lead-zinc mine, grind it to -0.074mm (100%), wash it three times with water to remove flotation reagents from its surface; place the tailings, water, and sodium hydroxide in a reactor for heated leaching at 220℃ for 120min, with an alkali-to-residue mass ratio of 2:1 and a liquid-to-solid ratio of 5:1. Cool to room temperature, and after solid-liquid separation, obtain leaching residue and leachate; take 100ml of leachate and place it in a beaker, place the beaker in a constant temperature water bath at 80℃, add 3% sodium sulfate electrolyte, and add 10% sulfuric acid solution dropwise at a certain stirring rate, controlling the pH at the reaction endpoint to be 7; react for 1-2 hours, and after the reaction is complete, age it at a constant temperature for 2 hours, and after aging, separate the solid and liquid; wash the solid repeatedly with water, and finally dry it in an oven at 100℃ to obtain hydrated silica, i.e., white carbon black product. The specific surface area of ​​silica is 195.67 m².2 / g, this product meets the highest category A requirements in the national standard GB / T10722.

[0019] Example 2 Take 100g of tailings (75% silica content) from a quartz vein-type lead-zinc mine, grind it to -0.074mm (100%), wash it three times with water to remove flotation reagents from its surface; place the tailings, water, and sodium hydroxide in a reactor for heated leaching at 220℃ for 120min, with an alkali-to-residue mass ratio of 2:1 and a liquid-to-solid ratio of 5:1. Cool to room temperature, and after solid-liquid separation, obtain leaching residue and leachate; take 100ml of leachate and place it in a beaker, place the beaker in a constant temperature water bath at 80℃, add 3% sodium sulfate electrolyte, and add 10% sulfuric acid solution dropwise at a certain stirring rate, controlling the pH at the reaction endpoint to be 7; react for 1-2 hours, and after the reaction is complete, age it at a constant temperature for 2 hours, and after aging, separate the solid and liquid; wash the solid repeatedly with water, and finally dry it in an oven at 100℃ to obtain hydrated silica, i.e., white carbon black product. The specific surface area of ​​silica is 217.31 m². 2 / g, this product meets the highest category A requirements in the national standard GB / T10722.

Claims

1. A method for recycling and utilizing quartz vein lead-zinc mine tailings, characterized in that: The resource recovery and utilization method of the quartz vein type lead-zinc mine tailings includes pretreatment, leaching, and main reaction steps, specifically including: A. Pretreatment: Grind the quartz vein lead-zinc ore tailings to be treated to -0.074 mm to obtain material a; B. Leaching: adding water and sodium hydroxide to material a and placing it in a reactor for heating and leaching, and obtaining leachate b and leach residue c after solid-liquid separation; C. Main reaction: add electrolyte sodium sulfate to the leachate b, add 8-12% sulfuric acid solution dropwise in a constant temperature water bath at 70-90°C for 1-2 hours, and control the pH value at the end point of the reaction to be 6.5-7.5; after the reaction is completed, age for 1.5-2.5 hours at a constant temperature of 70-90°C, separate the solid and the liquid, repeatedly wash the obtained solid with water, and dry it to obtain hydrated silicon dioxide.

2. The method for recycling quartz vein lead-zinc mine tailings according to claim 1, characterized in that: Step A also includes washing material a with water 2 to 4 times to remove the flotation agent on its surface.

3. The method for recycling quartz vein lead-zinc mine tailings according to claim 1, characterized in that: The leaching temperature in step B is 210~230℃.

4. The method for recycling and utilizing quartz vein lead-zinc mine tailings according to claim 1, characterized in that: The leaching time in step B is 100~150min.

5. The method for recycling and utilizing quartz vein type lead-zinc mine tailings according to claim 1, characterized in that: In step C, the amount of electrolyte sodium sulfate added is 2-4% of the mass percentage of the leaching solution.

6. The method for recycling and utilizing quartz vein type lead-zinc mine tailings according to claim 1, characterized in that: The volume percentage concentration of the sulfuric acid solution in step C is 8-12%.

7. The method for recycling and utilizing quartz vein type lead-zinc mine tailings according to claim 1, characterized in that: In step C, the drying is carried out in an oven at 90-110°C.