CN104779403B - Method for improving manganese leaching rate of waste zinc-manganese battery by applying ultrasonic technology - Google Patents

Abstract

The invention discloses a method for improving the leaching rate of manganese in waste zinc-manganese batteries by applying an ultrasonic technology. The method comprises the steps of splitting a waste zinc-manganese battery, screening out a positive electrode material, soaking, filtering, washing, drying, grinding and dispersing to obtain positive electrode material powder, and then carrying out leaching reaction under the action of ultrasonic waves by taking sulfuric acid as a leaching agent and hydrogen peroxide as a reducing agent. The method adopts an ultrasonic technology, shortens the leaching reaction time and improves the leaching rate of manganese in the acid leaching process of the waste zinc-manganese battery.

Description

Method of Improving Manganese Leach Rate in Waste Zinc-Manganese Batteries Using Ultrasonic Technology

technical field

The invention relates to a method for increasing the leaching rate, in particular to a method for increasing the leaching rate of manganese in waste zinc-manganese batteries by applying ultrasonic technology.

Background technique

my country is the country that produces the most dry batteries in the world, accounting for about 34% of the world's total output. Among them, 70% of the batteries are zinc-manganese batteries. There are more than 600,000 tons of zinc-manganese batteries scrapped in my country every year. If these scrapped batteries can be recycled, 71,000 tons of zinc and 112,000 tons of manganese can be obtained every year, which not only reduces environmental pollution, but also effectively reduces waste of metal resources. At present, the most common methods of disposing of waste zinc-manganese dry batteries in my country are manual sorting, dry method, wet method and dry-wet method. Among them, the wet treatment technology is more suitable for large-scale promotion. This method is to separate the positive and negative electrode materials from the dissected battery, and then perform pretreatment to obtain battery powder, and immerse it in an acidic solution, and then use chemical precipitation, electrochemical Sedimentation, ion exchange or extractive separation methods allow the recovery of target components in the form of pure metals or metal salts. However, there are still many key scientific and technical problems that have not been resolved in the process of wet recycling of waste zinc-manganese batteries, especially in the leaching process, there are problems such as long leaching time, high acid concentration, high reaction temperature, and excessive liquid-solid ratio. Low leaching efficiency and other disadvantages. In recent years, it has been found that ultrasonic technology can enhance the leaching rate of valuable metals in the leaching process, and its mechanism is mainly reflected in the following aspects: (1) create new active surfaces; (2) promote the original cracks on the mineral surface (3) Increase the migration rate of the solute during the leaching process; (4) Improve the wettability of the solid-liquid interface; (5) Promote chemical reactions, etc. The invention proposes a new method for improving the leaching rate of manganese in waste zinc-manganese batteries by using ultrasonic technology.

Contents of the invention

The object of the present invention is to provide a method for improving the leaching rate of manganese in waste zinc-manganese batteries by using ultrasonic technology. In the acid leaching process of waste zinc-manganese battery positive electrode materials, ultrasonic technology is used to increase the contact area between solid and liquid, and accelerate the solidification process. , The flow and exchange of the liquid interface keeps the surface of the solid particles highly active to shorten the leaching reaction time and increase the leaching rate of manganese.

The specific steps are:

(1) Raw material pretreatment: First, dissect the used zinc-manganese battery, and screen out its positive electrode material; soak the obtained positive electrode material in distilled water for 24 hours, filter it with suction, wash it with distilled water for 3~4 times, and store it at 80 ℃ Dry for 12 hours, grind and disperse to obtain a pretreated positive electrode material powder.

(2) Ultrasonic enhanced leaching: add a sulfuric acid solution with a concentration of 2.0~4.0 mol/L into the three-necked flask and place it in an ultrasonic reactor, add a mechanical stirring device, a condensation reflux device and a thermometer to the three-necked flask, and start the mechanical stirring device to 400 r/min, when the temperature of the sulfuric acid solution reaches 30-70 °C, according to the concentration of 2.0-4.0 mol/L sulfuric acid solution and the liquid-solid ratio of the positive electrode material powder (liquid volume mL to solid mass The ratio of g) is 6~14:1. Add the positive electrode material powder obtained in step (1) into the three-necked flask, and at the same time turn on the ultrasonic wave (frequency 45 kHz, power 40~80W), and add 5 mL mass percent concentration of 30 % hydrogen peroxide, after reacting for 20-100 minutes, carry out solid-liquid separation to obtain leachate.

The invention has the advantages of adopting ultrasonic technology, shortening the leaching reaction time of waste zinc-manganese batteries, and increasing the manganese leaching rate.

detailed description

The present invention has been specifically described below through the examples, it should be pointed out that the following examples are to further illustrate the present invention, rather than limit the protection scope of the present invention, those skilled in the art can make some non-essential according to the above-mentioned content improvements and adjustments.

Experimental raw materials: waste Nanfu brand mercury-free zinc-manganese batteries;

Experimental equipment: ultrasonic cleaner (KQ2200DE), electric mixer (SJB-S)

Example 1:

Effect of Ultrasonic Power:

(1) Raw material pretreatment: Firstly, the waste zinc-manganese battery was cut open, and the positive electrode material was sieved out; the obtained positive electrode material was soaked in distilled water for 24 hours, then suction filtered, washed with distilled water for 3 times, and dried at 80°C for 12 hours. Hours, after grinding and dispersing, the pretreated positive electrode material powder was obtained.

(2) Ultrasonic enhanced leaching: Add 30 mL of sulfuric acid solution with a concentration of 3.0 mol/L into a 250 mL three-necked flask and place it in an ultrasonic reactor, add a mechanical stirring device, a condensation reflux device and a thermometer to the three-necked flask, and start Mechanical stirring device to 400 r/min, when the temperature of the sulfuric acid solution reaches 50 ℃, according to the concentration of 3.0 mol/L sulfuric acid solution and the liquid-solid ratio (liquid volume mL to solid mass g Add 3.0 g of positive electrode material powder obtained in step (1) into the three-necked flask at a ratio of 10:1, and turn on the ultrasonic wave (frequency 45 kHz, power 40 W, 50 W, 60 W, 70 W, 80 W), and add 5 mL of hydrogen peroxide with a concentration of 30% by mass percentage, react for 60 minutes, and perform solid-liquid separation to obtain leachate.

By changing the ultrasonic power, the experimental results are shown in Table 1.

Table 1: Effect of ultrasonic power on manganese leaching rate

Power/W 40 50 60 70 80 Leaching rate/% 65.1 69.8 73.3 72.1 71.5

It can be seen from Table 1 that when the ultrasonic power is 60 W, the leaching rate of manganese is the highest.

Example 2:

Effect of sulfuric acid concentration:

(1) Raw material pretreatment: Firstly, the waste zinc-manganese battery was cut open, and the positive electrode material was sieved; the obtained positive electrode material was soaked in distilled water for 24 hours, then suction filtered, washed with distilled water for 4 times, and dried at 80°C for 12 hours. Hours, after grinding and dispersing, the pretreated positive electrode material powder was obtained.

(2) Ultrasonic enhanced leaching: Add 30 mL sulfuric acid solutions with concentrations of 2.0 mol/L, 2.5 mol/L, 3.0 mol/L, 3.5 mol/L and 4.0 mol/L into five 250 mL three-neck flasks and place them side by side In the ultrasonic reactor, five three-neck flasks were respectively connected with a mechanical stirring device, a condensation reflux device and a thermometer, and the mechanical stirring device was started to 400r/min. When the temperature of the sulfuric acid solution reached 50°C, the sulfuric acid solution and the steps ( 1) The liquid-solid ratio (ratio of liquid volume mL to solid mass g) of the obtained positive electrode material powder is 10:1. Add 3.0 g of the positive electrode material powder obtained in step (1) to five three-necked flasks respectively, and simultaneously open the Ultrasonic (frequency 45 kHz, power 60 W), and 5 mL of hydrogen peroxide with a concentration of 30% by mass was added, reacted for 60 minutes, and separated solid-liquid to obtain leachate.

By changing the initial concentration of sulfuric acid, the experimental results are shown in Table 2.

Table 2: Effect of sulfuric acid concentration on manganese leaching rate

Sulfuric acid concentration/(mol/L) 2.0 2.5 3.0 3.5 4.0 Leaching rate/% 60.5 66.3 73.3 73.9 74.4

It can be seen from Table 2 that the higher the concentration of sulfuric acid, the higher the leaching rate of manganese, but when the concentration reaches 3.0 mol/L, the leaching rate of manganese changes slowly with the concentration of sulfuric acid. Considering the consumption of sulfuric acid, the concentration of leaching agent should be selected 3.0 mol/L.

Example 3:

Influence of reaction temperature:

(1) Raw material pretreatment: Firstly, the waste zinc-manganese battery was cut open, and the positive electrode material was sieved; the obtained positive electrode material was soaked in distilled water for 24 hours, then suction filtered, washed with distilled water for 4 times, and dried at 80°C for 12 hours. Hours, after grinding and dispersing, the pretreated positive electrode material powder was obtained.

(2) Ultrasonic enhanced leaching: Add 30 mL of sulfuric acid solution with a concentration of 3.0 mol/L to five 250 mL three-necked flasks and place them in ultrasonic reactors. Mechanical stirring devices, condensation Reflux device and thermometer, start the mechanical stirring device to 400 r/min, when the temperature of the sulfuric acid solution reaches 30 ℃, 40 ℃, 50 ℃, 60 ℃ and 70 ℃ respectively, according to the concentration of 3.0 mol/L sulfuric acid solution and step ( 1) The liquid-solid ratio (ratio of liquid volume mL to solid mass g) of the obtained positive electrode material powder is 10:1. Add 3.0 g of the positive electrode material powder obtained in step (1) to five three-necked flasks respectively, and simultaneously open the Ultrasonic (frequency 45 kHz, power 60 W), and 5 mL of hydrogen peroxide with a concentration of 30% by mass was added, reacted for 60 minutes, and separated solid-liquid to obtain leachate.

By changing the leaching reaction temperature, the experimental results are shown in Table 3.

Table 3: Effect of reaction temperature on manganese leaching rate

Reaction temperature/℃ 30 40 50 60 70 Leaching rate/% 61.6 67.4 73.3 81.4 75.6

It can be seen from Table 3 that the leaching rate of manganese is the highest when the reaction temperature is 60 °C. If the temperature is too high, H ₂ O ₂ will be decomposed and the leaching rate will decrease.

Example 4:

The influence of liquid-solid ratio:

(1) Raw material pretreatment: Firstly, the waste zinc-manganese battery was cut open, and the positive electrode material was sieved; the obtained positive electrode material was soaked in distilled water for 24 hours, then suction filtered, washed with distilled water for 4 times, and dried at 80°C for 12 hours. Hours, after grinding and dispersing, the pretreated positive electrode material powder was obtained.

(2) Ultrasonic enhanced leaching: In five 250 mL three-necked flasks, the liquid-solid ratio of the sulfuric acid solution with a concentration of 3.0 mol/L and the positive electrode material powder obtained in step (1) (ratio of liquid volume mL to solid mass g) Add 18 mL, 24 mL, 30 mL, 36 mL and 42 mL of 3.0 mol/L sulfuric acid solution at a ratio of 6:1, 8:1, 10:1, 12:1 and 14:1 respectively and place in In the ultrasonic reactor, a mechanical stirring device, a condensation reflux device and a thermometer were respectively added to the five three-necked flasks, and the mechanical stirring device was started to 400 r/min. When the temperature of the sulfuric acid solution reached 60 °C, the five three-necked flasks were Add 3.0 g of the positive electrode material powder obtained in step (1) to the mixture, turn on the ultrasonic wave (frequency 45 kHz, power 60 W), and add 5 mL of hydrogen peroxide with a concentration of 30% by mass, react for 60 minutes, and carry out solidification. Liquid separation to obtain leachate.

By changing the liquid-solid ratio, the experimental results are shown in Table 4.

Table 4: Effect of liquid-solid ratio on manganese leaching rate

Liquid-solid ratio/(mL/g) 6 8 10 12 14 Leaching rate/% 59.3 69.8 81.4 82.6 83.7

As can be seen from Table 4, the leaching rate of manganese increases with the increase of the liquid-solid ratio. When the liquid-solid ratio is greater than 10, the leaching rate of manganese increases slowly with the liquid-solid ratio. The larger it is, the more waste acid will be produced, which is not conducive to subsequent process treatment, so the optimal liquid-solid ratio is 10:1.

Example 5:

Comparison of the leaching effect of manganese with and without the application of ultrasonic technology:

(1) Raw material pretreatment: Firstly, the waste zinc-manganese battery was cut open, and the positive electrode material was sieved; the obtained positive electrode material was soaked in distilled water for 24 hours, then suction filtered, washed with distilled water for 4 times, and dried at 80°C for 12 hours. Hours, after grinding and dispersing, the pretreated cathode material powder was obtained.

(2) Leaching with or without the application of ultrasonic technology: add 30 mL of sulfuric acid solution with a concentration of 3.0 mol/L into two 250 mL three-necked flasks and place them in ultrasonic reactors. Mechanical stirring device, condensing reflux device and thermometer, start the mechanical stirring device to 400 r/min, when the temperature of the sulfuric acid solution reaches 60 ° C, according to the concentration of 3.0 mol/L sulfuric acid solution and the positive electrode material powder obtained in step (1) The liquid-solid ratio (ratio of liquid volume mL to solid mass g) is 10:1. Add 3.0 g of positive electrode material powder obtained in step (1) to two three-necked flasks respectively. At the same time, in one case, turn on the ultrasonic wave ( frequency 45 kHz, power 60 W), and added 5 mL of hydrogen peroxide with a concentration of 30% by mass percentage, and directly added 5 mL of hydrogen peroxide with a concentration of 30% by mass percentage in the other case, and reacted for 20 minutes, 40 minutes, and At 60 minutes, 80 minutes and 100 minutes, solid-liquid separation was carried out to obtain leachate.

By changing the leaching reaction time, the experimental results are shown in Table 5.

Table 5: Comparison of the leaching rate of manganese with and without the application of ultrasonic technology

It can be seen from Table 5 that under the same leaching conditions, the application of ultrasonic technology can effectively improve the leaching rate of manganese in waste zinc-manganese batteries.

Claims (1)

1. A method for improving the leaching rate of manganese in waste zinc-manganese batteries by applying an ultrasonic technology is characterized by comprising the following specific steps:

(1) Pretreatment of raw materials: firstly, splitting a waste zinc-manganese battery, and screening out a positive electrode material of the waste zinc-manganese battery; soaking the obtained positive electrode material in distilled water for 24 hours, then carrying out suction filtration, washing with distilled water for 3 to 4 times, drying at 80 ℃ for 12 hours, and grinding and dispersing to obtain pretreated positive electrode material powder;

(2) Ultrasonic enhanced leaching: adding a sulfuric acid solution with the concentration of 2.0 to 4.0 mol/L into a three-neck flask, placing the three-neck flask in an ultrasonic reactor with the frequency of 45 kHz, respectively connecting a mechanical stirring device, a condensation reflux device and a thermometer to the three-neck flask, starting the mechanical stirring device to 400 r/min, adding the anode material powder obtained in the step (1) into the three-neck flask according to the liquid-solid ratio of the sulfuric acid solution with the concentration of 2.0 to 4.0 mol/L to the anode material powder obtained in the step (1), namely the ratio of liquid volume mL to solid mass g being 6 to 14, when the temperature of the sulfuric acid solution reaches 30 to 70 ℃, simultaneously starting ultrasonic waves with the frequency of 45 kHz and the power of 40 to 80W, adding 5 mL of hydrogen peroxide with the mass percent concentration of 30%, reacting for 20 to 100 minutes, and then carrying out solid-liquid separation to obtain a leachate.