Metal prices have been rising since 2003. During 2003-2006, gold & aluminum prices became two times higher, and copper & zinc prices 4∼5 times higher. In particular, 2006 prices were skyrocketing, and the comparison of selected metal prices between 2005 and 2006 indicates steep rise; zinc (236%), copper (183%), nickel (165%), gold (136%) and aluminum (135%). The current higher metal prices are supported by expanding metal demands by BRICs countries (Brazil, Russia, China and India), and inflow of speculative market into mineral commodities. The current higher metal prices have a great influence on non-ferrous metals industry, and is creating several issues from the viewpoint of countries, corporation, and stake holders. This paper includes (1) current soaring prices of non-ferrous metals, (2) impact of higher metal prices on world major companies and (3) influences of current world mining business on Japanese smelting companies. Along with the soaring metal prices during 2003-2007, world major mining companies (Majors) rose record of high level profits particularly in 2006, which promoting M & A (Merger and Acquisition), and/or higher convergence of Majors. The analysis of influences of world mining trends on Japanese smelting companies will be summarized as is shown below; (1) M & A brought the higher convergence of Majors. For example, copper mining production rates by best 5 companies rose from 32% in 1990 to 41% in 2006. (2) Under the competitive copper concentrate market due to the emergence of China, Japanese smelting companies are confronting with difficulties in TC/RC (Treatment Charge and Refining Charge) negotiations with Majors such as BHP Billiton.
Present status and issues of non-ferrous extractive metallurgy were described in this short review from resource and environmental points of view. Recent trend of shortage of non-ferrous ores and severe regulations gave several impacts to non-ferrous extractive metallurgical industry, although significant innovations of non-ferrous extractive metallurgical processes have not been done in this decade. There are three big issues in the society. The first one is how to control iron, sulfur and minor impurities like arsenic. Sulfur is over supplied in the world, then more than 10 millions tons sulfur are stored near oil and natural gas refineries. Therefore, a development of new application of sulfur is still essential. Usage of slag is also big problem. Since regulations on the usage of slag became severe, we have to change a mind that slag is not a sink of minor impurities but an important by-product containing iron which is major impurity in non-ferrous ores. Good collaboration of each non-ferrous smelter and refinery will be required to keep them in Japan to treat not major non-ferrous metals but harmful minor elements like arsenic and cadmium. Keeping non-ferrous industry is one of keys to achieve the sustainable development in Japan.
This paper describes the outline of comminution and separation technology for creating the “Sound Material Circulation Society”. In especial, the importance of such technology was emphasized by introducing the “3R” concept. Improving mechanism of the liberation of compositional materials in comminution process, properties of two kinds of separation technologies, soft and hard separations, applicable size range for soft separation, adequate combination flow of separation technologies, and evaluation method of separation results were introduced.
The purpose of this article is to analyze recycling of used materials with resource potential as well as pollution potential from a viewpoint of environmental economics. It surveys the present circumstances of material and resource circulation, and shows how smooth recycling can be promoted in a market economy if it is supported by a formal regime of material circulation. In such a material circulating economy, resource potential of residuals which have once been treated as waste is realized as real market value, while their pollution potential is not realized. It is also demonstrated that promotion of recycling extends the life of landfill on one hand, and reduces the price of used materials on the other. An increase in the foreign demand for waste materials tends to arrest their price reduction. Yet, it is anticipated that recycling of waste materials in developing countries can not afford to deter their pollution potential, and may possibly diffuse real pollution.
The current flow of international trade of recyclable waste and secondhand goods are reviewed. China is a major importer of metal scraps in Asia. Hazardous wastes are also traded for recovering metals. There are several problems related to international trade of recyclable waste. Some of wastes are recycled without environmentally sound technology, causing pollution problems. Some hazardous wastes or non-recyclables are exported for disposal, under the name of recyclables. On the other hand, the regulations to control international trade become a barrier to the activity of good recyclers, who comply the regulation, because the formal procedure to export and import hazardous waste takes a long time before shipment. To encourage the sound-material circulation society in Asia, it is important to tighten the enforcement of the Basel Convention, and to reduce the too high barrier for transboundary movement destined for recyclers with environmentally sound technologies.
Kosaka smelter started copper production in 1901 using blast furnace, and diversified into other products and metallurgical technologies that treated complex concentrates produced at black ore mine. Black ore is complex sulfide ore containing many valuable metals such as copper, zinc, lead, gold and silver. And main processes are composed of copper operation that consist of flash smelting furnace and PS converter, and lead operation using hydrometallurgical treatment plant and electric furnace. However, social and economical situation changed worldwide in recent year, domestic black ore mines closed one after another and last black ore mine closed in 1994. But complex nature of black ore has made the capabilities to treat large variety of low materials and complex concentrate. And Kosaka smelter started restructuring measure to cope with this harsh business environment. The cores of the plan were improving the performance of complex smelting technologies to precious metal production and expansions to recycling business and waste management business. This paper introduces recent copper operation and describes about an outline of the modification.
Copper smelting with green charged reverberatory furnaces has been operated since 1965 at Onahama Smelter and Refinery. Recycling business has been progressed during the last decade as well as many improvements for copper smelting and refining process. Shredder residue derived from automobile scrap and others, has been treated in the reverberatory furnaces at 140,000 t per year recently.
Hitachi refinery of Nikko Smelting & Refining Co. Ltd. changed its operation scheme by introducing the ISA permanent cathode technology for the first time in Japan in December 2002. The change resulted in higher productivity, better cathode quality and lower operational costs. The operation has been continuously improved to reach a 20% higher production capacity than the original one. For the electrolyte purification process, the Hitachi refinery introduced a sulfuration process in April 2001. This process removed sulfide (As, Sb and Bi) formed by the reaction of hydrogen sulfide from electrolyte with increasing in production of copper cathode by partially eliminating liberator cells.
Tamano Smelter & Refinery of Hibi Kyodo Smelting Co., Ltd. started its operation in January, 1972. The production capacity of electrolytic copper has gradually increased and it reaches 260,000t/y now. In the last decade, 2 times production expansions were executed in order to achieve further cost saving and high production efficiency. This paper describes the various developments which were commissioned during the decade.
The Mitsubishi Naoshima Smelter & Refinery started copper smelting operation in 1917, since then has been developed smelting and refining technologies like Mitsubishi Process, which is an efficient, pollution free continuous copper smelting and converting process. At present, Naoshima Smelter & Refinery has three major activities; copper business, precious metals business and recycling business. In this decade, Naoshima Smelter & Refinery has been utilized the copper smelting technology for recycling business, which consists of the treatment of the industrial wastes and the treatment of copper and/or precious metal-bearing materials. Two recycling plants were constructed as pre-treatment plants for Mitsubishi process. One is the incinerating and melting plant, and the other is washing treatment plant for fly ash from incinerators. The treated industrial waste from these recycling plants is fed to Mitsubishi Process to recover the valuable materials and hazardous heavy metals.
Sumitomo Toyo Smelter and Refinery commenced its operation in 1971 with the “To Be a Pollution-Free and World’s Cleanest Copper Smelter Forever” motto. From early 1990’s to 2003, Toyo Smelter and Refinery increased its annual electrolytic copper production from 200,000 tonnes to 270,000 tonnes with the continuous technological improvements and no addition of any excess facilities. From the turn of the century, the forecast that the world copper demand would increase steady but surely especially in Asia has been rushing the other smelters into the reinforcements of their facilities and the foundations of the new plants. It is clear that this situation will lead to the age of the jungle law in the next depression. Then Sumitomo Metal Mining Co.,Ltd. has decided to increase its Toyo Smelter and Refinery’s annual production capacity to 450,000 tonnes in order to meet the demand growth and to ensure its survival by minimizing its production cost. Toyo Smelter and Refinery has finished its expansion works and would start the 450,000 tonnes production from the end of 2007.
In 1996 Saganoseki Smelter & Refinery integrated its two flash furnaces to one in order to reduce the operating cost and maintain the global competitiveness. And then many improvements were carried out to expand the smelting capacity. However, the copper content in concentrates had been decreased and also the anode production was limited. Therefore, the next project, which is called SPI (Saganoseki Process Innovation) project, was needed and started in 2003. In this project not only the smelting section but whole series of the process were modified and the productivity had been improved remarkably. The activity of SPI project and operational changes of Saganoseki Smelter & Refinery in the last decade are introduced in this paper.
Kosaka Smelting and Refining Co., Ltd. operates lead smelting to produce electrolytic lead and to recover precious metals and bismuth with mainly secondary materials from copper smelter and zinc refinery. The lead-bearing residue from zinc refinery is filtered and is dried with the leached residue from copper smelting flue dust. Then these are fed to an electric furnace with some reductant and other lead secondaries to produce lead bullion. The electro-refining of lead is based on Betts process. And we produce crude silver and bismuth metal from anode slime. According to a change of raw materials for the zinc refinery, the residue from that plant changed to high impurity contents. This raw material change becomes a very big problem for the lead smelting in Kosaka and we are doing various improvement. It is very important for lead smelting not to play rolls as the attached process of copper smelter, the zinc refinery and as the production plant of variable metal. Therefore, we are going to introduce a new technology to recover the some metals that we recognized as impurities. The recent lead operation and some experiments for lead smelting in Kosaka are described in this paper.
The Chigirishima Smelter of Toho Zinc Co., Ltd. is located on Chigirishima island of Hiroshima Prefecture. The smelter is a custom lead smelter and its operation was started in 1951. At present, the smelter produces 8,000 tons per month of electrolytic lead. This paper describes significant improvements and achieved results in by-products production process.
In 2003, the lead smelting unit of Takehara Refinery transformed to accept a new mission. This mission uses a blast furnace that has been in operation since the 1970's, and a locally developed process. Formerly, recyclable materials such as used batteries and lead residue had been treated to produce crude lead. In the middle of 2003, we changed the mission to one of charging precious materials such as used PC electric circuits and lead residue from the copper refining process to produce crude lead, gold, and silver. Accordingly, our process uses newly developed equipment to dissolve dioxins in exhaust gas. As a result of implementing the new process, the gold amount contained in the crude lead increased 185% in comparison with the previous process. This paper describes these recent operations at the lead smelting unit of Takehara Refinery.
In 1972 Akita Zinc Co., Ltd. commenced operations with the annual capacity of 78,000 ton of electrolytic zinc, and it had operated with its annual capacity of 156,000 t-Zn since 1974. The business surroundings for zinc production has been coming severer with some economical reasons. Then we tried to survive with some improvements, and succeeded to reduce the operating cost and to get more profits as follows; 1) expansion of its producing capacity to 200,000 t-Zn annually, 2) saving man-power by introduction of fully-automated machines for cathode handling at cell house operation, 3) improvement of Hematite process by means of recovery of rare-metals and arsenic removal. These measures improved profitability of Akita Zinc. But the market for zinc raw material is changing drastically and we have to treat more secondary materials by environmental reasons.
Annaka Refinery of Toho Zinc Company Limited, located 100km to northwest of Tokyo, has the annual production capacity of about 140,000tons of electrolytic zinc. On the other hand Onahama Refinery, located 200km to northeast of Tokyo, has the fluosolid roaster which treats 500ton per day of zinc concentrate and produces 570tons of sulfuric acid. Onahama plant provides about 150,0000tons zinc calcine per year for Annaka plant. This paper describes significant improvements and achieved results at the both Refineries during the last decade.
Kamioka Mining and Smelting Co., Ltd. became independent of Mitsui Mining and Smelting Co., Ltd. in 1986. Kamioka’s metallurgical operation consists of zinc electrolytic winning, lead smelting and lead electrolytic refining. The company’s main products are electrolytic zinc, electrolytic lead, zinc alloy, silver, cadmium, bismuth and sulfuric acid. Our metallurgical operation developed together with the mining operation at Kamioka mine, but the raw materials at zinc plant and lead plant were changed due to the reducing of the mine products. The new technologies that we developed to change the raw materials and the power that is supplied from the hydropower plants are our advantages. We will make effort to survive in Japan with these advantages.
Hikoshima Smelting Co., Ltd. is located at the western end of Honsyu. The plant switched from a horizontal retort process to an electrolytic zinc process in 1970. Hikoshima Co., Ltd. had made various improvements to reduce the operating costs about roasting, leaching, purification, electrolysis, casting, labor-saving and so on. In addition, the annual capacity extended from 55,000 tons to 74,000 tons during several expansion stages. Main products are zinc alloys for hot galvanizing and zinc anodes for plating. This paper describes these recent improvements and operations.
Hachinohe Smelting Company Limited operates the largest Imperial Smelting Furnace (ISF) in the world, producing 112,000 t/y of zinc and 45,000 t/y of lead. The slag fuming plant has been operating in the smelter since 1993 for the recovery of zinc and lead from the ISF slag. In November 2001 the second slag fumer was commissioned in series with the existing fumer to improve the quality of slag for use in cement manufacture and to increase zinc and lead recovery in the fume. Along with the increase of zinc production, the on-site power generating capacity was uprated from 7.5MW to 9.6MW in April 2001. As much as 70% of the total power requirement is supplied by the own power plant. In recent years, up to 40% of the feed materials have comprised secondary zinc materials.