• Resources Recycling
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• 제27권1호
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• pp.3-13
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• 2018

3D printing, also known as Additive Manufacturing (AM), is being positioned as a new business model of revolutionizing paradigms of existing industries. Launched in early 2000, 3D printing technology for architecture has also advanced rapidly in association with machinery and electronics technologies mostly in the United States and Europe. However, 3D printing systems for architecture require different mechanical characteristics from those of cement/concrete raw materials used in existing construction methods. Accordingly, in order to increase utilization of raw materials produced in the cement and resource recycling industry, it is necessary to develop materials processing and utilization technology, to secure new property evaluation and testing methods, and to secure database related to environmental stability for a long period which aims to reflect characteristics of an architectural 3D printing technology.

• Resources Recycling
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• 제23권5호
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• pp.68-79
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• 2014

Since 1990s, efforts to recycle the waste plastics by chemical methods have increased. And in accordance with this trend, attempts have become active to use the waste PET as raw materials of chemical industries. In this article, the patents and papers for development of commercial technology for feedstock recycling and high end products from PET wastes were collected and analyzed. The open patents of USA (US), European Union (EP), Japan (JP), and Korea (KR) and SCI journals from 1974 to 2013 were investigated. The patents and papers were collected using key-words and filtered by the definition of the technology. The patents and papers were analyzed by the years, countries, companies, and technologies and the technical trends were discussed in this paper.

• Resources Recycling
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• 제13권5호
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• pp.3-16
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• 2004

There are over 190,000 tons per year of the sludge containing heavy metals (SHM) generated from industries in Korea. The SHM is so hazardous waste, it needs proper intermediate treatment before final disposal. At present, the common intermediate treatment and final disposal technologies of SHM are solidification and landfill. However, the future treatment and disposal technologies of SHM will be carry out to fulfill in both the environmental aspect and resource recycling. Thus, how to reduce the generation of SHM and recycle the valuable metal from SHM become the major subjects in the global world. In this article, in order to prospect the effective processing of SHM, the generation and processing of the sludge from plating wastewater, the research and development of valuable metal recycling technology and problems were summarized.

• Resources Recycling
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• 제27권6호
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• pp.76-83
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• 2018

This article aims to summarize the scrap recycling status of gold, silver, platinum and palladium from foreign countries by courntires and industries in order to utilize the data for securing the raw materials of the domestic urbanmining industry. The amount of gold from scrap has shown a tendency to decrease in countries other than China, which is attributed to the large imports of scrap containing gold in China. The industry demand for gold is the highest in electronic products, but demand is decreasing. The amount of scrap recycling in silver has declined in other regions compared to those in Europe, indicating that the world's overall scrap recycling volume has declined. Production and demand from scrap of platinum and palladium are mostly for catalysts and have been steadily increasing until now. However, it is expected that the amount of waste catalysts in automobiles will decrease with the increase of electric vehicle use.

• Journal of Energy Engineering
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• 제27권1호
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• pp.40-50
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• 2018

Today, the development of industries and rapid urbanization has a profound impact on the human environment. It can be said that the environment in the craft village is most affected. The environment in these areas is severely degraded and depending on the type of production, the environment in the craft villages is different. In Phong Khe ward of Bac Ninh Province, Vietnam, there are over 204 small and large facilities of recycling and producing paper. The paper facilities produce about 200,000 tons of paper each year and the amount of paper produced is not less than 500 tons each day in Phong Khe. They are creating livelihoods for more than 6,000 workers and generating local budgets from VND- 50 billion to VND 60 billion per year. Despite this great contribution, the use of old machines and "backward" modes of production means that paper recycling has caused serious air, soil, and water pollution in the region. The specific objectives of this study were as follows: (1) provide an overview of paper production process in the Phong Khe paper craft village; (2) comprehensive literature review of the current status of water environment, atmosphere environment, soil environment and solid waste; (3) figure out about waste treatment in Phong Khe ward.

• Environmental Engineering Research
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• 제23권3호
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• pp.323-329
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• 2018

The municipal solid waste (MSW) management system in one of the Class II Indian cities i.e. Rishikesh was studied and analysed to identify the key issues in solid waste management in the city. A total of 329 solid waste samples from 47 households were collected to characterize the household solid waste (HSW). The average (HSW) generation rate was 0.26 kg/c/d and it was composed of organic waste (57.3%), plastics (14%), paper (10.9%), and glass and ceramic (1.3%) and other materials (16.5%). There was an inverse relationship between household waste generation rate and family size (p < 0.05). The MSW management system practiced in Rishikesh is unsound. There is no waste segregation at source, no provisions of composting and no recycling by formal sector. The collection and transportation of waste is inadequate and inappropriate. Collected waste is dumped in open dumping site without scientific management. Following are some recommendations for developing a sustainable solid waste management system in Rishikesh city: (1) sensitize people for segregation at source; (2) promote reduction, reuse and recycling of wastes; (3) promote community based composting; (4) provision for 100% door to door collection and; (5) formalize the informal sectors such as rag pickers and recycling industries.

• Journal of Powder Materials
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• 제28권2호
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• pp.91-96
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• 2021

Rare earth magnets with excellent magnetic properties are indispensable in the electric device, wind turbine, and e-mobility industries. The demand for the development of eco-friendly recycling techniques has increased to realize sustainable green technology, and the supply of rare earth resources, which are critical for the production of permanent magnets, are limited. Liquid metal extraction (LME), which is a type of pyrometallurgical recycling, is known to selectively extract the metal forms of rare earth elements. Although several studies have been carried out on the formation of intermetallic compounds and oxides, the effect of oxide formation on the extraction efficiency in the LME process remains unknown. In this study, microstructural and phase analyses are conducted to confirm the oxidation behavior of magnets pulverized by a jaw crusher. The LME process is performed with pulverized scrap, and extraction percentages are calculated to confirm the effect of the oxide phases on the extraction of Dy during the reaction. During the L ME process, Nd is completely extracted after 6 h, while Dy remains as Dy₂Fe₁₇ and Dy-oxide. Because the decomposition rate of Dy₂Fe₁₇ is faster than the reduction rate of Dy-oxide, the importance of controlling Dy-oxide on Dy extraction is confirmed.

• Journal of the Korean Society of Mineral and Energy Resources Engineers
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• 제56권4호
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• pp.359-366
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• 2019

This article aims to summarize the recycling status of scrap gold, silver, platinum, and palladium by regions and industries in order to utilize the data for securing raw materials of the domestic urban mining industry. The amount of gold from scrap has shown a tendency to decrease in countries other than China over the last ten years, which is attributed to the increase in scrap containing gold in China. The industry demand for gold is the highest in electronic products, but it is decreasing. The amount of scrap recycling for silver has declined but total silver production has increased by increasing mine products. As production and demand from platinum and palladium scrap are mostly for catalysts, their demand could be affected by the electric vehicle industry.

• Proceedings of the IEEK Conference
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.71-75
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• 2001

The first step for recycling the CRT bulb is to remove frist seals between the panel and funnel. For this purpose, various kinds of methods have been used. One of those is to use the nitric acid, which is a proven technology and widely used in CRT-making industries. The process. however. has a problem of NOx generation. Such a drawback can be overcome by using a new chemical. This new chemical can remove the frit without NOx generation. This paper describes the dissolution ability of the chemical for lead and zinc oxides and the application to the separation of the CRT panel from its funnel.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 한국자원리싸이클링학회 2005년도 제13회 산화철워크샵
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• pp.3-14
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• 2005

We Investigated minutely how the biosorption technology using algal biomass is opened in Canadian technology society. Making comparative study for relative technologies in views of overall unit operation cost, we could grasp next facts. - Algal biomass plays the competitive performance for various metals. - Algal biomass biosorbent is regenerated. - Reactor system is not and involved one. This means that algal biomass occupies the strong position as biosorbent. Especially, in North America, for the purpose of metal bearing wastewater treatment, 20 hundred million US dollars was appropriated a sum for the purchase of ion exchange resin. But it is only thirty million US dollars if algal biomass biosorbent is used on behalf of ion exchange resin. Furthermore, the expenses for same treatment can be cut down additively through metal recovery.