Used lead-acid batteries have high recycling value, but improper handling can easily cause serious environmental pollution. The recovery systems, policies and regulations, and recycling technologies of foreign developed countries are worth learning and learning from.
Used lead-acid batteries have become hot spots in the circular economy because of their high recycling value. However, if waste lead-acid batteries are handled and disposed improperly, they can easily cause serious environmental pollution and threaten human health. Therefore, used lead-acid batteries are also internationally recognized as hazardous waste.
In recent years, countries around the world have paid more and more attention to the recycling of lead. Western developed countries have even encouraged both the economy and the legislation to recycle used lead-acid batteries and made great progress. In China, although the recycling of used lead-acid batteries started earlier (in the 1950s), but for decades, due to various reasons, the recovery technology has developed slowly. In recent years, with the improvement of people’s awareness of environmental protection, the country has introduced a number of relevant policies and regulations and increased investment in this area, but the effect is minimal. At present, although the technical level of a few formal enterprises has reached the international advanced level, the overall technical level of the country is still relatively backward. The construction of recycling systems for used lead-acid batteries and the formulation of relevant policies and regulations need to be further improved, and the gap with the developed countries in the world It also needs further reduction.
The recovery model of foreign used lead-acid batteries The developed countries in the world attach great importance to the recovery and recycling of used lead-acid batteries. In western and middle developed countries, there are mainly three recycling methods for used lead-acid batteries:
The first route is for battery manufacturers to organize recycling through their retail networks;
The second route is operated by coalitions and recycling companies that specifically collect waste lead-acid batteries and lead-containing wastes that are approved under government regulations. These waste companies collect used lead-acid batteries, lead, and other lead from various possible sources. After the waste, it will be resold to a remanufactured lead plant that has a large-scale business license;
The third method is to establish a specific waste lead-acid battery recovery and cleaning company to operate in a reconstituted lead factory. The methods used include: trade-in, mortgage payment, provision of special signs, and collection of environmental taxes. After cleaning the recovered used lead-acid batteries, they returned directly to the reclaimed lead plant.
Practice has proved that as long as there are appropriate laws and regulations to ensure that these kinds of recycling methods are effective, in most developed countries have achieved satisfactory results, and now the recycling rate of used lead-acid batteries in developed countries basically reached 100%.
In France, before the end of the 1980s, recycling was almost completely completed by scrap buyers. However, there are many disadvantages to this collection method. There is the problem of arbitrary acid and acid leakage, and there are hidden dangers in environmental protection and safety. As a result, a recycling system that is organized and more environmentally friendly is being developed. This recycling method needs to follow certain rules of operation: the sealed plastic bucket is handed over to the customer for storage of the battery, and the plastic bucket is transported to a stacking platform called a “dedicated space†with a truck equipped with a movable tailgate. Leak-proof devices are installed on the platform to prevent the outflow of acid; waste batteries are sent to battery production workers in sealed, acid-resistant drums. Currently, there are three types of people or organizations that can implement this organized recycling system: battery wholesalers, multiple scrap purchasers, and manufacturers. These people can be divided into two categories: one is the acquisition of waste products, they can recover two-thirds of the waste batteries, supply to battery buyers and wholesalers; the other is an organized recycler, including professional recycling Many waste recyclers and some manufacturers can only recover one-third of used batteries.
In Australia, battery manufacturers are responsible for recalling, collecting waste batteries, wrapping them in bales, sending them to remanufactured lead manufacturers with special transportation tools, and paying certain hazardous waste disposal fees; recycling lead plants will collect disposal fees and processing fees. Return the recycled lead to the battery factory.
The foreign countries' encouragement (restriction) policy on the recycled lead industry has developed a relatively complete legal and regulatory system for the recycled lead industry, and has particularly strict regulations on environmental protection issues. The industry’s operations have been incorporated into the legal system and promoted. Industry development. As early as March 1991, the European Union issued a directive document on hazardous materials for waste batteries, 9l/157, which stipulates the marking of batteries containing more than 0.4% lead and the method of disassembling batteries from instruments and equipment. The public is obliged to return unused batteries in cars and electric vehicles to retailers or recycling stations for free in exchange for the deposits paid at the time of battery purchase. If they are not returned, the deposit is deducted; the remanufactured lead plant is also A portion of the funds that must be derived from the production of such waste batteries should be used for the investment and development of environmental protection equipment.
In terms of setting up a reconstituted lead plant, the construction of a foreign reconstituted lead plant must first obtain the permission of the national environmental protection department and issue a hazardous waste disposal operation permit. Because lead is highly toxic, the production of recycled lead abroad can only be concentrated in the hands of a few large companies from the perspective of environmental protection, technology, and economy. Generally, only one or two companies with a production scale of 20,000 tons/year or more are established in a region. The following table shows the number and scale of regenerative lead production enterprises in developed countries in the world. In foreign developed countries, the government does not allow malicious competition in the industries involved in environmental protection, which is conducive to the development of renewable lead resources to environmental protection and industrialization.
The developed countries have strict laws and regulations on the recycling of waste batteries. Take Japan as an example: The public can't mix waste batteries with ordinary solid municipal wastes, and they can't throw them away. They can't dismantle and pour acid, but they should be completely sent to designated waste battery recycling stations. The recycling station is set up by the battery manufacturer. The manufacturer is responsible for recalling the waste battery, then collecting it from the recycling station, packing it with plastic cloth, and transporting it to the reclaimed lead plant for disposal. After the reclaimed lead plant cracks the waste battery, it is smelted into recycled lead and sold to the battery manufacturer. However, the battery manufacturer must allocate the disposal fee to the price of each battery according to a certain proportion when the battery is sold, and the public shall bear it. Its cycle mode is as follows:
In the above closed-circuit cycle, if there is found to be disposable, dismantled batteries, dumped waste acid, it is fine; in addition, the nearby soil shall be sampled and tested regularly. Once the environment is found to be polluted, heavy penalties will be imposed and permanent responsibility shall be imposed.
Overview of Recovered Lead Recovery Technology Abroad The developed countries currently use the entire broken battery mechanical crushing and sorting method to divide the entire battery into waste acid, grid, lead paste, waste plastics, and waste separators. The waste acid is reused after being treated in the wastewater treatment tank; the grid can be made into alloy or crude lead directly by low-temperature smelting; the sulfur-containing lead paste is desulphurized using desulphurization pretreatment technology, and then the fire method, wet method or dry method is respectively adopted. The wet combination process recovers lead; plastics are sold as by-products after cleaning. This mechanical operation on the one hand effectively avoids the lead poisoning of workers in the production process and reduces the labor intensity of workers; on the other hand, it separates the grid material and the paste mud, reduces the amount of material entering the furnace, and improves the lead of the charge. Grades, thereby reducing the amount of flue gas, spoil, dust, energy, sulfur dioxide emissions, improve the metal recovery, ergonomics and productivity, which is very beneficial to environmental protection. Most of the reduction and smelting of lead paste uses rotary kiln fuel, using clean energy automatic temperature measurement, automatic feeding, using bag dust to automatically control the flue gas, smoke and dust emissions inside and outside the workshop, to achieve the required environmental protection requirements, so that the recovery rate of metal lead Greater than 95%. In the final disposal of waste residues, foreign countries have adopted concentrated deep landfills to further control the residual hazard of residual lead on the soil. Fig. 1 is a flow chart of a foreign classic lead-fire smelting process, and Fig. 2 is a battery smashing and sorting device.
World production and distribution of recycled lead Since the 1960s, the world’s primary lead production has gradually declined, and lead production has gradually increased. Compared with other metals, lead recycling and recycling are much easier. Therefore, lead has the highest recycling rate among all metals. In the 1980s and 1990s, the world’s lead production exceeded that of primary lead production.
The recycled lead industry occupies an important position in the world's lead industry. In 2003, the world's recycled lead accounted for half of the total lead production. The United States is the world’s largest producer of recycled lead. In 2003, the output of recycled lead reached 803,900 tons, accounting for 58% of the total output of refined lead (1.3802 million tons); Germany was 62%, and France was 98%. Italy 93%. , Japan 64%. In 2006, the world's recycled lead production reached 3,111,200 tons (data from China Nonferrous Metals Renewal Branch).
The world's renewable lead production capacity is mainly concentrated in North America, Europe and Asia, of which recycled lead production in North America accounts for 47.3% of the world’s total lead production. Recycled lead production companies are mainly distributed in the United States, the United Kingdom, France, Germany, Japan, Canada, Italy, Spain, and China. According to the ratio of lead lead production to total lead consumption, they can be divided into three types:
1In countries that do not produce primary lead, only a small amount of lead is produced. Such countries include Spain, Ireland, Portugal, Switzerland, Nigeria, and New Zealand;
(2) Countries that account for more than 50% of recycled lead production include the United States, Germany, Italy, the United Kingdom, Japan, Canada, Belgium, and France;
(3) Countries with less than 50% of lead production are mainly developing countries such as China.