Subject Research Metal Foreign Waste

Selection of topic

When choosing a research topic, we were very interested in the topic "Recycling and Utilization of Waste 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 lives. However, it can be said that as many batteries are produced as they are eventually discarded; centralized production leads to dispersed pollution; short-term use leads to long-term pollution. Nowadays, the harm of waste batteries has become an environmental issue of common concern to people all over the world. Countries around the world are researching the best way to deal with used batteries. Although fruitful results have been achieved, this problem cannot be fundamentally solved. Therefore, finding the best way to deal with waste batteries has become a scientific research direction for many scientists in various countries.

Our students are also a group that uses batteries. As a cross-century generation, we should improve our environmental awareness and recycle batteries starting from me. Therefore, five of our first-grade students chose this topic as their own research topic.

Research process and results

1. Topic selection

At the beginning, several of us discovered in our daily lives that there are waste battery recycling bins in some shopping malls. Why should batteries be recycled after use? We are very curious about this. Therefore, when the school launched a research study course at the end of November last year, we chose this topic as a research topic.

2. Setting the topic

Initially, the topic we decided on was "Why should waste batteries be recycled?" To this end, we have collected an extensive collection of relevant questions. In the first group meeting, after intense discussions and listening to the teachers’ opinions, we believed that we should not just limit our attention to recycling, but also expand the topic to another issue that attracts more attention - Regarding energy issues, we finally determined the topic as "Recycling and Utilization of Waste Batteries".

3. Proposal

In the second concentration, we analyzed the status of the topic and clarified the purpose and significance of the topic, the academic purpose of the topic research, and the main focus of the topic research. The content and research features and innovations were also divided into groups and the activity steps were designed. Based on these we filled out the proposal report.

IV. The implementation of our research is divided into five stages:

Phase 1: From January 17th to February 14th this year, through the Internet and books Find relevant information through library searches and other methods. After searching a lot of information, we learned that (1) waste batteries are potential killers of human health

The batteries people use daily rely on chemical action, and in layman's terms, rely on corrosion to produce electrical energy. The harmful substances such as heavy metals chromium, mercury, cadmium, etc. are extremely harmful to the human body. One button battery can pollute 600,000 liters of water, and one AA battery rotten in the ground can make one square meter of land lose its use value. Therefore, the recycling of waste batteries is imperative.

(2) Waste batteries contain treasures

Waste batteries not only bring harm to human beings, they also contain many resources. For example, button batteries contain lithium, manganese, silver and other rare metals; lead-acid batteries contain lead; mobile phone batteries contain cadmium. The recycling value of these substances is very high. Some factories have begun to carry out recycling and extraction work in this area. In addition, ordinary dry batteries also contain zinc, copper, manganese powder and other resources.

As the subject continues to deepen, we have become interested in the actual recycling and treatment process of waste batteries. So

Phase 2: In mid-February, we visited the waste battery recycling factory---Dalian Development Zone Dongtai Company. And interviewed their Chief Engineer Liu.

Through interviews, we learned that the international community attaches great importance to the disposal of waste batteries. There are generally three internationally accepted methods of disposal of used batteries: solidification and deep burial, storage in waste mines, and recycling.

Many countries in Western Europe use special sieves to screen out button batteries from collected waste batteries and extract the mercury contained in them for use. The remaining types of waste batteries are generally transported to special toxic and hazardous landfills. Not only does this approach cost too much, but it also causes a waste of useful materials.

A "wet treatment" device is being built in the suburbs of Magdeburg, Germany. In addition to lead-acid batteries, all types of batteries are dissolved in sulfuric acid. The raw materials obtained in this way are relatively pure. 95% of the various substances contained can be extracted.

The harm of waste batteries in our country has received great attention from the country and has been included in the key projects of the Tenth Five-Year Plan. Relevant policies will be introduced this year. At present, there is no unified method for disposing of used batteries in our country. However, it is reported that my country will adopt wet processing for waste batteries.

Through this on-site visit, we not only gained a deeper understanding of the hazards of waste batteries and the resources contained in them, but also strengthened our sense of social responsibility in protecting the environment. Thus we enter the third stage.

Stage 3: At the end of February this year, with the help of the school Youth League Committee and other teachers and the school student union, we conducted a publicity activity on waste battery recycling inside and outside the school. After the promotional activities, the students were not limited to these. Everyone hopes to design a recycling plan based on the actual situation of our school. So we entered stage 4.

Phase 4: In early March, use the recycled waste batteries and use the school laboratory to design a set of recycling experiments for the reuse of waste batteries based on the actual situation of the school. The recycling plan is as follows:

[Experimental drugs] Several AA dry batteries; 3% hydrogen peroxide solution; synthetic detergent; silver nitrate aqueous solution; sodium hydroxide solution

[Experimental instruments ] Hammer, scissors, beaker, iron stand with iron ring, funnel, filter paper, glass rod, evaporating dish, crucible, alcohol lamp, test tube

[Experimental steps]

1. Recycling of manganese dioxide

Carefully smash the waste battery, take out the black content, wash it with clean water several times, dry it in the sun, and heat it in an evaporating dish to remove the carbon particles in the manganese dioxide. Burn it, stir it while heating, and after cooling it can be used to produce chlorine and oxygen. The temperature should not be too high when heating to prevent deterioration:

4MnO2 2Mn2O3+O2↑

2. Extract ammonium chloride

Put the black substance from the battery into Stir to dissolve in water and filter. Place part of the filtrate in an evaporating dish to evaporate to obtain a white solid. After heating, use "sublimation" to collect purer ammonium chloride.

3. Preparation of zinc granules

Cut the zinc flakes on the zinc cylinder into pieces, place them in a crucible under strong heat (the melting point of zinc is 419°C), and carefully remove the zinc after melting. Pour the liquid into cold water to get zinc particles.

4. Verify manganese dioxide

Add 3ml of 3% hydrogen peroxide solution and 3-4 drops of synthetic detergent solution into two test tubes respectively. Add a small amount of the prepared black solid to one of the test tubes. If the reaction speed is faster than that of the other test tube, the black solid is manganese dioxide.

5. Verify ammonium chloride

Add 3ml of a concentrated solution made of white solid into two test tubes, and add sodium hydroxide solution dropwise into the first test tube. If there is a pungent smell gas escaping , indicating that the concentrated solution contains ammonium ions. Add acidified silver nitrate solution dropwise to the second test tube. If a white precipitate forms, it means that the solution contains chloride ions. This proves that the white solid is ammonium chloride.

Stage 5: At the beginning of April this year, our group began to finalize the topic, compile data, and write a paper. At the end of April, our group passed the selection and was recommended to participate in the school-wide research study report presentation.

After the school research study report, we wanted to further expand the scope of publicity about waste battery recycling, so we I chose the newly opened Wal-Mart supermarket near the school. There we disseminated leaflets and posted slogans to educate people on why used batteries should be recycled.

Feeling

It lets us know how to learn. In the past, I always learned as much as the teacher taught me, and I was helpless when I encountered something that the teacher had not taught me. Through this research study, even if we encounter something that the teacher has not taught in the future, we will know that we have to go to the library or go online to find information and conduct self-study.

——Shi Xiuwen

Research-based learning activities have expanded our knowledge and improved our social communication skills. In order to complete this research study, we not only searched for relevant information on the Internet, but also visited and visited the factory on the spot. Although we were very nervous when interviewing Chief Engineer Liu and forgot to ask many questions, we all thought this event was particularly meaningful.

—Liu Jing

Through this research course, I felt the importance of collective collaboration and enhanced my organizational skills.

The most important thing is to make us realize the seriousness of environmental pollution problems and establish our awareness of loving and protecting the environment.

——Zhao Yanyan

We are no longer afraid of doing chemical experiments. In our impression, chemicals seem to be scary, but through this research study, we realized that chemicals will not harm us as long as they are used correctly. Now I hope that the second round of research study activities will start soon.

——Zhang Xiuyun

Through research-based learning activities, I realized that science means seeking truth from facts. The pursuit of truth requires a firm belief. In the face of setbacks, you cannot give up or give up. Have the spirit of courage to advance and explore. I really realize that scientific achievements are hard-won.