When choosing the research topic, we are very interested in the topic of "recycling of used batteries". As we all know, with the continuous development of science and technology and the continuous improvement of people's living standards, the use of batteries has become an indispensable part of our daily life. However, the battery can be said to be how much it is produced and how much it will eventually be discarded; Centralized production and decentralized pollution; Short-term use and long-term pollution. Nowadays, the harm of waste batteries has become an environmental problem that people all over the world pay close attention to. Countries all over the world are studying the best scheme to deal with waste batteries. Although fruitful results have been achieved, this problem cannot be fundamentally solved. Therefore, finding the best solution to deal with waste batteries has become the research direction of many scientists in various countries.
We students are also battery users. As a cross-century generation, we should raise our awareness of environmental protection and recycle batteries from me. Therefore, five students in our senior one chose this topic as their own research topic.
Research process and results
First, the topic selection
At the beginning, several of us found that some shopping malls had waste battery recycling bins in our daily lives. Why should batteries be recycled after use? We are curious about this. Therefore, we chose this topic as the research topic after the school opened the research-based learning course at the end of June last year 165438+ 10.
Second, determine the topic
At first, the topic we decided was "Why recycle used batteries". To this end, we have extensively collected relevant issues. At the first group meeting, after heated discussion and listening to the teacher's opinions, we thought that we should not only focus on recycling, but also expand the topic to another issue that is more concerned-energy, so we finally decided that the topic was "Recycling of used batteries".
Third, open the topic.
In the second concentration, the status quo of the project was analyzed, the purpose and significance of the project, the academic purpose of the project research, the main contents, research characteristics and innovations of the project research were clarified, and the activities were divided into groups and designed. Based on these, we filled out the opening report.
Fourth, the implementation of our research is divided into five stages:
Stage 1: June 65438+1October 17 to February 14 this year, and consult relevant materials through the internet and the library. Looking up a lot of information, we know (1) that waste batteries are potential killers of human health.
The batteries used in people's daily life are all produced by chemical action, which is commonly called corrosion. Among them, heavy metals such as chromium, mercury and cadmium are very harmful to human body. A section of button cell can pollute 600,000 liters of water, while a section of No.1 battery rotted in the ground can make a square meter of land lose its use value. Therefore, the recycling of waste batteries is imperative.
(2) There are treasures in waste batteries.
Waste batteries are not only harmful to human beings, but also contain many resources. For example, button cell contains rare metals such as lithium, manganese and silver; Lead storage batteries contain lead; Mobile phone batteries contain cadmium and have high recycling value. At present, some factories have begun to recycle and extract in this respect. In addition, ordinary dry batteries also contain resources such as zinc, copper and manganese powder.
With the deepening of the subject, we are interested in the actual recycling process of used batteries. therefore
The second stage: In mid-February, we visited Dongtai Company in Dalian Development Zone, a waste battery recycling factory. And interviewed their chief engineer Liu.
Through interviews, we know that the international community attaches great importance to the disposal of waste batteries. There are generally three ways to deal with waste batteries in the world: solidification and burial, storage in abandoned mines and recycling.
Many countries in western Europe will first screen out button cell from the collected waste batteries with a special sieve, and extract the mercury contained in it for utilization. The remaining waste batteries are generally transported to a special toxic harmful waste landfill. This practice is not only too expensive, but also wastes useful materials.
A "wet treatment" device is being built in the suburbs of magdeburg, and all kinds of batteries except lead batteries are dissolved in sulfuric acid. The raw materials obtained in this way are relatively pure, and 95% of the substances contained in the battery can be extracted.
The harm of waste batteries in China has been highly valued by the state and included in the key projects of the Tenth Five-Year Plan, and relevant policies will be issued this year. At present, there is no unified method to treat waste batteries in China. However, it is reported that China will use wet method to treat waste batteries.
Through this field trip, we not only have a deeper understanding of the harm of waste batteries and the resources contained in them, but also enhance our sense of social responsibility to protect the environment. So we entered the third stage.
The third stage: at the end of February this year, with the help of teachers such as the Youth League Committee and the Student Union of our school, we organized a publicity campaign on the recycling of used batteries inside and outside the school. After the publicity activities, the students are not limited to these. Everyone hopes to design a recycling plan according to the actual situation of our school. So we entered the fourth stage.
The fourth stage: at the beginning of March, according to the actual situation of the school, a set of recycling experiments of used batteries was designed by using the school laboratory. The recovery plan is as follows:
[Experimental drug] 1 A number of dry batteries; 3% hydrogen peroxide solution; Synthetic detergent; Silver nitrate aqueous solution; Sodium hydroxide solution
【 Experimental instruments 】 Hammer, scissors, beaker, iron frame with iron ring, funnel, filter paper, glass rod, evaporating dish, crucible, alcohol lamp and test tube.
[Experimental Steps]
1. Recovery of manganese dioxide
Carefully smash the waste battery, take out the black content, rinse it with clear water for many times, dry it in the sun, heat it in an evaporating dish to make the carbon particles in manganese dioxide burn, stir it while heating, and cool it to obtain chlorine and oxygen. When heating, the temperature should not be too high to prevent deterioration:
4MnO2 2Mn2O3+O2↑
2. Extraction of ammonium chloride
The black substance of the battery mechanism was dissolved in water, filtered, and part of the filtrate was evaporated in an evaporating dish to obtain a white solid. After heating, pure ammonium chloride was collected by sublimation.
3. Preparing zinc particles
Cut the zinc sheet on the zinc cylinder into pieces, put it in a crucible, and strongly heat it (the melting point of zinc is 4 19℃). After melting, the zinc liquid is carefully poured into cold water to obtain zinc particles.
4. Verify manganese dioxide
Add 3 ml of 3% hydrogen peroxide solution and 3-4 drops of synthetic detergent solution to the two test tubes respectively. A small amount of prepared black solid is added to one of the test tubes, and if the reaction speed is rapidly accelerated compared with the other test tube, this black solid is manganese dioxide.
5. Verify ammonium chloride
Drop 3 ml of concentrated solution made of white solid into two test tubes respectively, and drop sodium hydroxide solution into the first test tube. If the gas with pungent smell escapes, it means that the concentrated solution contains ammonium ions. Drop the acidified silver nitrate solution into the second test tube. If a white precipitate is produced, it means that the solution contains chloride ions. It is proved that the white solid is ammonium chloride.
The fifth stage: At the beginning of April this year, our group began to complete the project, collect data and write papers. At the end of April, our group passed the selection and was recommended to participate in the school-wide report and display of research learning results.
After the report of research study in our school, we want to further expand the publicity scope of waste battery recycling, so we chose the newly opened Wal-Mart supermarket near our school. There, we publicize the truth that used batteries should be recycled by distributing leaflets and posting slogans.
feel
It lets us know how to study. In the past, teachers always taught and learned a little, but they were at a loss when they met something the teacher didn't say. Through this research study, even if we encounter something that the teacher hasn't said in the future, we know that we should go to the library or the Internet to find information and conduct self-study.
-Shi Xiuwen
Research-based learning activities have expanded our knowledge and improved our social skills. In order to complete this research study, we not only consulted relevant information on the Internet, but also visited the factory on the spot. When interviewing Chief Engineer Liu, although everyone was very nervous and forgot to ask many questions, we all felt that this activity was particularly meaningful.
Liu Jing
Through the study of this research course, I feel the importance of collective cooperation and enhance my organizational ability. The most important thing is to make us aware of the seriousness of environmental pollution, and let us establish the consciousness of loving and protecting the environment.
—— Zhao Yanyan
We are no longer afraid of doing chemical experiments. In our impression, chemicals seem terrible, but through this study, we realize that chemicals will not harm us as long as they are used correctly. Now I hope that the second round of research-based learning activities can start as soon as possible.
-Zhang
Through research-based learning activities, I realized that science is practical and realistic. In the process of pursuing truth, we should have firm faith, never give up in the face of setbacks, and have the spirit of going forward and being brave in inquiry. I really realized the hard-won achievements of science.