Resources supply and environmental protection are increasingly becoming matters of global concern. With increased industrial activities worldwide, a possibility for exhaustion of mineral resources as projected from past demands stirred much controversy regarding the future supply of metals. Mass production and mass consumption generate massive quantities of industrial scrap as well as post consumewastes. Mounting public sentiment against construction of new landfill sites necessitates volume reduction of wastes to be disposed. Incineration is an effective way to conserve landfill spaces, but the potential generation of dioxins and underground water contamination by incinerator residues are becoming a growing public concern. Establishment of social systems for waste minimization and promotion of re-use as well as of technology for improving recycling efficiencies are needed for sustainable development. In this article, concerns over mineral resources supply, issues in environmental protection, and the problems and technological developments associated with recycling are summarized.

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The regulations on waste treatment in Japan show dynamic movements toward “Establishment of Recycling-based Society”, “Waste Reduction”, “Propulsion of Recycling”, “Reinforcement of Management on Chemical Substances” in considering waste as an environmental risk, “Self Management System” represented by ISO14000 series and “Reinforcement of Regulations and Standards”.
To understand the Japanese laws and regulations on waste treatment, understanding of the whole environmental laws and international trends on environment is essential, since Japanese laws and regulations have been reflected by those trends and movements. Especially, “Waste Disposal and Public Cleaning Law” and “Law for Promotion of Utilization of Recyclable Resources” put emphasis on proper treatment of generated waste and recycling for the reduction of waste respectivery, and these two laws are the core of the Japanese waste treatment laws.

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Man-made resources which should be utilized valuably and effectively is generated from each industryall over the world. This paper describes the following subjects:(1) The generation, disposal and utilization of man-made resources; and (2) New strategies and future trends for information management of manmade resources.
First subject includes a situation of present problems and difference of waste definition for industrial waste in the world. Second subject includes outline of waste information and information management system in our country.

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The treatment and recycling flow of copper-containing waste such as power lines, telecommunication cables, railways cables, electric appliances, machines, automobiles, industrial machines and buildings were studied. The main results are as follows in thousand of tons in 1994 in Japan.
A total of 560 thousand tons of old scrap copper were estimated to be generated, in which 197 were from power lines, telecommunication cables and railways cables, 128 from electric appliances and machines, 48 from automobiles, 61 from industrial machines, 126 from buildings. A total of 382 thousand tons were recycled either in Japan (337) or abroad (45) and the residual 178 was estimated to be landfilled.

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Zinc is one of the most important metal element for our living. It is no doubt that recycling is the most important issue for industry. Secondary zinc industry has been established based on economical situation. But still important problems on zinc recycling have been remained. In this report the outline of zinc recycling is discussed. The most important issue on zinc recycling is treatment of EAF dust from steel recycling system and fly ash of incineration process. Both materials include certain amount of halogen elements. They cause several problems on their treatment process. It would be emphasized that combination of steel making process and non-ferrous metal smelting process could give the solution not only on future zinc recycling but on the waste management in Japan.

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Because of the steady increase in car population and the mounting of enviromental concern, lead consumption ratio for lead-acid batteries is tending to gradually increase. As a result of this fact, itis important to establish new reliable collection, treatment, and recycling system of used lead-acidbatteries that would not to be effected by the fluctuation of lead prices and the exchange rate. Andlead-acid batteries made of lead, dilute sulfuric acid and polypropylene have to be treated withoutcausing any enviromental problem.
In Japan, in October 1994, the battery manufacturing industry started the a “lead recyling system”.
As maintenance-free batteries using no Pb-Sb alloy as grid arewidely used, demand for secondary Pb-Sb alloy has decreased.
To maintain the usage amount of secondary lead as lead-acid battery, primary smelters were asked toparticipate in this recycle system.Afterthe introduction of this system, recyclig ratio for lead-acid batteries has risen to about 90%contributing to stabilized recycling ratios.

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1. “Japan Spent Catalist Recovering Association” have meny Rare Metal Recycling result. If you have interest, directly enquer above Association.
2. Our caltivated technics.
1) Solvent of precias metal recently useing Iodin, we collect this spent water and Iodin recovering.
2) Inorganic coagulater.
As now glass polishing agent Cerium Oxide useing, our coagulater “Colgelite” have good water reduction, planning CeO₂ recovery.

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Brief historical and commercial information precedes a statement of the sources of ‘secondary precious metals’ materials and a discussion of the pyrometallurgical and chemical treatment circuits. Examples are given of the evaluation methods of materials being treated and pre-sampling methods of treatment and plant used are outlined. Descriptions are given of the work done by Mochikoshi factory, Chugai mine Co., at their refineries with regard to pyrometallurgical treatment, the electro-refinery and chemical treatment, reference being made to new ideas and modifications under investigation at the present time.

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In recycling of aluminum, the quality and the yield of molten aluminum at remelting are important subjects. For recycled products, secondary aluminum material used to be predominant but now compounds of 4iu minum and polymers account for the majority. This paper focuses on aluminum used beverage cans (U, 13, C.) as a typical example of recycled aluminum, and discusses the effects, etc. of pretreatment of material (paint removal by chemical method) on the molten aluminum quality and aluminum yield at remelting. The investigation results indicate that paint removal is effective for improving the molten aluminum quality, in partfeular, for reduction of impurity element titanium, as well as improving the aluminum yield.

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The world environmrntal problem has been a serious issue toward the next century. In Japan, the individual industries have solved the various problems on pollution and energy saving. However the present issue is entirely different from the past one. It is a more global and serious problem, how todeal with the enormous amount of waste flooding over the society.
The domestic stock of steel products is well over one billion tons in Japan and this causes a huge pressure to the society. Therefore, a completely new concept is necessary to recycle a huge amount of steel scrap. The idea is not on the extension of the same line but is different from the past tactics. The new idea is so called “TEMCOS”, (Total Energy and Material Control System). In this concept the waste material or productsmust be minimized from any sources and reused in the various industries within the society.
For example, the ferrous and non-ferrous industries have a well established system of minimizing waste material and preventing pollution. Waste material is generally recycled and reused within their works.So, the both industries may be able to cooperate each other to transfer and reuse the waste materialas new resources.
Simply speaking, energy and material will be controlled systematically to reachthe optimum condition in the entire society. The concept will be developed further in the future.

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One hundred million tons of crude steel are produced a year in Japan and the amount of slags produced with steel production is about 35 million ton. It is desirable that the amount of industrial wasteproduct is minimized in the ironmaking and steelmaking industry and the slags are recycled and used effectively as material resources in connection with the problems of the availability of natural resources and deterioration of environmental conditions. In this paper a general view of the present situation of slag recycling in the ironmaking and steelmaking industry is explained and the problems of slag recycling are discussed.

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Effective utilization of slags is one of the most significant issues in the metal industries. Non-ferrous metallurgical slags are becoming widely used in these days, the usage is however far from satisfactory level. In this paper, the current situation and problems on the matter are discussed concerning about copper smelting slag, lead and zinc slag and ferro nickel slag. Simultaneously, relationship between the crystalline phases of these slags changed by cooling condition and the alkali-silica reaction is briefly discussed.

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The present status on the production and waste treatment of used tires in Japan are summarized and the recent activities of research on the recycling of used tires are introduced.
For recycling used tires, liquid-phase cracking was tried using various kinds of solvents under low pressure of N₂-H₂. Experiments were carried out using a 200ml autoclave with magnetic stirrer at 300-440°C, initial H₂or N₂pressure of 2.0-8.5 MPa, reaction time of 20-60 min with solvent to tire weight ratio of 1-2.5. When hydrogen donating solvent such as tetralin was used for cracking, almost all organic matter could be converted to light oil with very low sulfur content of 0.5 wt% by the reaction under low nitrogen pressure. Reaction residue can also be reused as carbon black for rubber manufacturing.

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The material recycling rate of the plastic wastes in 1995 was 11%, which means 950, 000 tons of plastic were recycled as the materials. Taking a look at them by the production sources, the plastic wastes such as the waste pieces from molding processes, off-specification products, etc. amount to about 780, 000 tons with its material recycling rate of around 98%. On the other hand, the plastic wastes from the distribution and marketing fields amount to 3.63 million tons with the recycling rate of about 5.8 %, while the household plastic wastes amount to 4.43 million tons with the recycling rate of insignificant 0.2%.
The material recycling of the plastic wastes from the household are just limited to such products as PSP trays and PET bottles witch are composed of single material and of collectable nature. When it comes to the promotion of recycling of the household plastic wastes, it is dfficult to collect only single material-products, thus, the chemical and thermal recycling methods are considered important.
The energy recovery by high efficient power generation and an intermediate system of collection such as the RDF method, the reduction to oil shall become important technologies. If we can reuse them successfully combining with the existing industries such as blast furnaces, cement kilns, etc., we shall be able to expect profitable recycling businesses at the reasonable cost and future development.

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Concerning recycle of OA equipment or other products, we have various domestic or overseas requirements. Such requirements are made, in the Class 1 Product Recycle Guideline of the Resource Recovery Promotion Act (previously so-called Recycle Act) which has been implemented in 1991, or recently in the “Green Purchase”, German Blue Angel Mark as well as VDI Guideline 2243. Here, I would like to look at “response to recycle” as social requirement, through the history of requirements of the Blue Angel Mark for OA equipment, particularly dry-type copier (UZ-62). Also, I would outline copier manufacturers' responses to recycle to cope with such situation. And finally, I would mention about the process whereby copier return to raw materials after ending their copying mission, to the full extent of our current knowledge. Hereafter, I will mention about: 1) History of requirements of the Blue Angel Mark; 2) Recycle concept of copier manufacturer; 3) Recyclable product design; 4) Construction of recycle system; 5) Collaboration among artery/vein industries.

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Although material recycle is at the highest priority in the cascade of recycling, it seems difficultto develop enough applications of recycled material realizing the high performance using powdered FRP as filler. In energy recycle, it is not possible to recover large enegy used for preparing the FRP. The difficult point of chemical recycle has been the separation and purification cost of decomposition products. Newly developed glycolysis of FRP is very promising in that the decomposition products can be used as a raw material for resin production without separation of constituent chemicals, and in that the remaining glass fiber has good property applicable to reinforcement.

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The volume of wastes in the wards area of the Tokyo Metropolis showed a maximam level in 1989, but in 1990's the waste output showed a decreasing tendency in eight consecutive years.
However, the volume of wastes collected and carried-in registered 4.2 million tons for one year and the total amount of wastes disposed of through landfilling came to about 2 million tons for one year.
The next and possibly last landfill site in Tokyo Bay, which also will last only about 15 years even if possible measures to reduce wastes carried there are taken, is planned to be built outside the present one.
The Tokyo Metropolis is now promoting reduction, recycling and intermediate processing of wastes in order to prolong the life of it.
Various types of melting methods are being developed to detoxify and reduce the amount of ashes generated in municipal solid waste incinerators.
Even now, we have never established the social and technical rule of recycling the melting slag and the melting fly ash.

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It has recently become necessary to develop a system for dealing with the large amounts of shredder dust generated declining abandoned automobiles and home electric appliances because of landfill space nationwide and stringent regulations on leachate control. In 1992, about 1.2 million tonnes of shredders containing an estimated 36 thousand tonnes of copper, 3.6 thousand tonnes of lead, 6 thousand tonnes of zinc and 5, 400 Gcal were derived from automobiles. The shredders from home electric appliance disposal accounted for 230 thousand tonnes containing 22 thousand tonnes of copper. The amounts of shredder dust has been estimated to increase to 1.37 million tonnes by 2000, and to 1.56 million tonnes by 2005.
A new project, the Recycle Mine Park (RMP) has been proposed to solve the problems of increasing amounts of automobile and home electric appliance scrap. The RMP uses technology to recover energy and metals. Since methods have been developed to recover energy and various kinds of metals including in base and hazardous metals, the largest problem of the project remains establishment of reasonable and economical system. About 30% of the shredder dust described above is generated in the western part of Japan.
Smelters are located on the coast of the Inland Sea of Seto in this area, which reduces the cost of transportion. The recycing network in the western part of Japan excluding pretreatment combines the best features of being in the vicinity of a large amount of shredder dust, marine transportion and the presence of modern smelters. Pretreatment such as incineration or cracking which is additional treatment for the smelter feed is proved in small scale.
Wehope that the unique system for recycing of shredder dust including collection, pretreatment, marine transportation and smeltering can be put into operation as soon as possible. The increasing costof suitable land for landfills, the stringent regulations on leachate control, and other costs makethis an attractive system.

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So called shredder dust/residue is of no unform characteristic, depending upon where and how one is separated out of shredded materials. There could be of course differences after each shredder plant system, and in our case, there are 10 different dusts emerging. They are all different in their characteristics, densities, outward apperances, and materials contained in them.
So far, some analyses made, qualitatively and quntataively, however, they are all of mixed-up shredder dusts, not separatly after each segment. For a better and proper recycling/disposal treatment of shredder dust, it seems imperative to have separate analysis for each dust to define each characteristic.
There are also differences after the matericals put into shredder system: in our main case, we put in whole cars, body, engine transmission and axles complete, although battery, tyres, and fluids all taken off. Normally, we are putting into shredder system, not complete car, but mainly bodies and engines /axles: differences are apparent, especially the densities of dusts and scraps out of them. The results with harder materials seem to better, even the production rate, however, no analyses of wear and tearin the system, and energy requirements being made.

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Shredder residue consists of many types of plastics, glasses and heavy metals. When it is landfilled, waste water which contains heavy metals is generated. Thermal processing technology should be developed in order to prevent environmental pollution and reduce its volume. Incinerating technology of shredder residue has been investigated by Nippon Mining & Metal group as a national project since November in 1996. Incineration pilot test plant was constructed by using the zinc smelting equipment which had already shut down in Nikko Mikkaichi Recycle. The incinerating capacity of the plant is 3 t/hr., and 1.5 t/hr. of shredder residue and 1.5 t/hr. of liquid waste are practically incinerated in the pilot test operation. Some operational troubles of the incineration caused by shredder residue have ocurried. Especially, the dust trouble in the off-gas treating plant was serious, However, the pilot plant has been improved, and most of the problems have been already solved. The generation of pollutants from the incineration plant has been kept as extremely low level by the off-gas treating plant and the waste water treating plant. Most of copper in shredder residue is distributed in the bottom ash, and 40% of lead and 30% of zinc are mostly distributed in the fly ash. The bottom ash and the fly ash are treated in the zinc smelting plant in order to recover zinc, lead and copper. Industrial technology of the incineration of shredder residue has been developed.

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We have developed the technology to treat automobile shredder residue (ASR) appropriately for the nonferrous metals recycling and non ferrous metals and refining technology. In this technology, we adopted twostage-carbonization process for reducing fatal factors such as chlorine problem and difficulty of handling of ASR. In this two-stage-carbonization process, PVC is decomposed selectively for the removal of chlorine at 350°C, then the residue of the first carbonization is carbonized for the decomposition of residual plastics at 550°C. Finally, nonferrous metals contained in the ASR is recovered as metal form and organic materials such as plastics is converted to gas, oil and carbon for the utilization as fuel.

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Dioxins and related compounds are known to be one of the most toxic chemicals. The major source of these chemicals are from the processes of waste treatment. To prevent adverse health effect for human, decreasing the dioxins emission from waste treatment has been focused in Japan. To promote this subject, it is important to develop the effective technique for waste management. On the other hand, the role of analytical technique is very important for the theme, as well.
This paper described the analytical methods for dioxins and related compounds resulted from waste treatment.

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In Japan, disposed automobiles are generally shredded. The valuable metals are recovered from this shredded materials and then the shredder residue is landfilled. However, by the problem of the shortage of reclaimed lands and of the soil pollution caused by the metals in the residue, needs for the material recycling from shredder residue are highlighted. Shredder residue contains nonferrous metals such as copper, lead and zinc. In order to prevent environmental pollution, these nonferrous metals should be recovered from the thermal processed residue of shredder residue. Recovery of nonferrous metals in the incinerated residue of shredder residue has been investigated by Nippon mining & metals group. In Nikko Mikkaichi Recycle Co., Ltd., copper residue and lead slime have beenrecovered from the incinerated residue in the zinc smelting plant. Copper residue was charged in the converter of copper smelting plant and electrolytic copper was recovered in Saganoseki Smelter & Refinery. Simultaneously, lead slime was treated in the lead smelting plant and crude lead was recovered. The recovery rates of copper, lead and zinc from shredder residue are proximately 90%, 96 96, 74% in the investigation.
Mitsubishi Materials Corporation has developed the recovery process of copper and lead by carbonizing shredder residue. The carbonized residue from the carbonization pilot plant of shredder residue was smelted and lead was efficiently recovered in crucible test. At the same time, the copper recovery process was investigated and the process by using conventional copper smelting plant was proposed. These processes are one of the effective methods to recover these metals.

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The separation unit, separation factor, total flow in separation system, energy requirement, and second wastes by separation for recycling system have been studied theoretically. Theoretical equationsof separation unit, and height of separation unit were introduced and it was pointed that the total flow in the separation unit was proportional inversely to the separation factor by two powers and the amount of the second waste materials is proportional to the factor. The second waste materials and the energy consumption should be considered in the aspect of the environmental assessment. The physical term and the social term have to be divided for the recycling separation more definitely than for the ordinal separation process.

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Aragonite type of calcium carbonate was synthesized via amorphous calcium carbonate from calcined scallop shell. The effect of aging and Mg²⁺ ion addition on polymorphism of the product was determined, and the mechanism of formation of aragonite is discussed. Aging of amorphous calcium carbonate first led to the formation of calcite and unstable vaterite, and the vaterite was then converted to aragonite with the longer aging. The addition of Mg²⁺ ions further enhanced the formation of aragonite. The elemental analysis by atomic absorption spectrometry and the characterization of the products by EPMA and XRD showed that Mg²⁺ ions were preferentially adsorbed on the calcite nucleus, then involved in the growing calcite (not needlelike crystal like aragonite). This adsorption inhibited the growth of calcite, leading to aragonite formation.

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The recycling of aluminum scrap reduces the energy consumption and environmental burden, comparing to the primary metal production. However, the amount of the recovered metal from scrap is limited because of the difficulties to remove the impurities in the scrap. Sometimes the removal of the impurities requires significant energy consumption.
The performance of the metal chlorination and co-generation procecss, in which aluminum scrap reacts with chlorine to form aluminum chloride and its reaction energy is recovered by electrochemical means, was investigated.
The power generation of about 6 W was accomplished with 20 mass % Cu added Al or 50 mass % Fe added Al. This power generationis almost equivalent to that with pure aluminum. The selective reaction of Al was also confirmed by the fact that there was no Cu or Fe in the dust and the salt electrolyte. This proved the high capability to purify aluminum from its scrap. The energy consumption in the total recycling system, whichconsists of the metal chlorination and co-generation, metal chlorides purification, and electro-winning, was evaluated to be less than half of that in the conventional Hole-Heroult process.

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In Japan, it can be easily predicted that rapidly increasing bottom and fly ash generated from municipal waste incineration will sooner or later fill up all the terminal waste management sites in this country. However, along with growing public consciousness toward environmental pollution, especially leaching of toxic materials from incineration residues being landfilled, it has become impossible to construct new waste management sites any more.
Under these circumstances, the authors have developed an ash-melting plant in which a shaft furnace similar to cupola in casting industry is installed. As the result of the trial operations, it made great performances and the molten slag products showed physical characteristics very close to those of crushed natural stone and chemical properties without significant leaching of hazardous materials.
It has apparent that the artificial aggregate obtained by crushing molten slag can be utilized into a variety of secondary concrete such as interlocking blocks, water-holding ceramics panels by calcining it with the other minerals and so forth. We consider that it could be the best way to utilize the artificial aggregate as base materials for road construction.
Many problems, however, such as necessity for further stabilization of the slag products as aggregate and management of hazardous heavy metals having escaped into the secondary or ash during the ash melting process, have been arising.

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The leaching of valuable metals from orimulsion burning ash collected from electro-precipitator of power plants was carried out by using aqueous hydrogen peroxide solutions. In the leaching using only water, the extraction fraction of vanadium and nickel was low in the water leaching. On the other hand, in the hydrogen peroxide leaching, the extraction fraction of vanadium and nickel increased with an increasing in the concentration of hydrogen peroxide. For instance, the extraction percentage of the metallic components on leaching for 60 minutes at 25°C and pH 2 with 2% H₂0₂ solution were 98.8% for V, 98.9% for Ni, 99.2% for Mg and 99.2% for Ca, respectively. Vanadium, nickel, magnesium and calcium were effectively extracted from the orimulsion burning ash with weak acidic solutions containing hydrogen peroxide.

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Recovery of leaded-frame metals from IC (integrated circuit) packages was carried out by crashing. IC packages were taken off from printed wiring boards, and these IC packages are DIP (dual in-line package) type having two lines of pins sealed with resin composition such as epoxy resin. IC package is composed of IC chips, metal lead frame, and sealing material, the content of metal is different depending on types of IC package, and lead frame are categorized into Fe-Ni alloy, Fe-Ni-Co alloy, and Cu alloy according to contained metal. Packaging material made by hardening mixture of thermosetting resin and quartz powder was crashed easily. Sealing material was separated easily by crashing regardless of the number of pin and lead frames of iron base alloy was separated easily by a magnet with a magnetic flux as low as 600 gauss.

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The total dissolution of spent hydrodesulfurization catalyst (HDS) in sulfuric acid yields an acidic solution containing a certain amount of rare metals like molybdenum, vanadium, cobalt, nickel, and a small amount of iron as well as large excess of aluminum. In order to recover Co and Ni from the raffinate after the selective extraction of Mo and V with phosphinic acid extractants such as CYANEX 272 and PIA-8, a systematic investigation was conducted on the synergistic extraction with the mixed solvents consisting of dinonylnaphthalenesulfonic acid (DNNSA) and a series of N-alkyl-bis-picolylamine such as tri-decyl-picolylamine (TDPA), oleylpicolylamine (OLPA), and octa-decyl-picolylamine (ODPA). It was elucidated that all of these mixtures could exhibit a good synergistic effect for the extraction of Co, and Ni, while, the extraction of Al was considerably suppressed. In particular, the mixture of TDPA, or OLPA in combination with DNNSA appeared to be the most feasible and economic because it has rapid extraction rate, good phase separation, and high selectivity for Co and Ni over Al. Stripping of the loaded Ni and Co can be achieved by 0.5 and 1 M sulfuric acid and hydrochloric acid, respectively. However, smooth phase disengagement was not observed, which should be improved in future, for example by employing picolylamines with highly branched alkyl chains at tail position.

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The purpose of this study was the recovery and effective utilization of manganese component from the used battery.
As manganese was included in the anode mixture for the cell, it was advisable to separate only the mixture from the used battery.
It was found that a hammer crusher was better in regard to the above purpose than the cutter mill, because part of the metallic Zn tended to be ground down in the case of the latter and be included in the pulverized fine powder with the anode mixture powder. The complete dissolution of Mn from the fine powder was difficult by sulfuric acid leaching but possible when water leaching with blowing SO₂at room temperature was performed. In the first step treatment of the leaching solution, all of Fe could be eliminated as the precipitation by adjusting pH of the solution below 6 and then both Mn and Zn could be precipitated completely in adjusting the pH above 10 after the elimination of Fe component.
It was possible to form the manganate which may be utilized as a soft ferrite material by heating of the prepicitation products obtained above pH 10.

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Recovery of Samarium and Neodymium from rare earth magnet scraps which contain-30% of Sm or Nd and 50-60% of Co or Fe was examined by the fractional crystallization of their sulfates. The results are summarized as follows: 1) When H₂SO₄was added into the nitric acid solution containing Sm and Co, the solubility of Sm decreased and Sm sulfate hydrate preferentially crystallized. 2) Samarium sulfate hydrate of 96.5% purity with recovery rate 87.1% was obtained from Sm Co₅magnet scrap by the fractional crystallization. Effective results were also obtained when Sm₂ (Co, Fe, Cu, Zr) ₁₇ was examined similarly. 3) The addition of ethanol into the sulfuric acid-nitric acid solution containing Nd and Fe was proved to be effective for the decrease of solubility and fractional crystallization of Nd. 4) Neodymium sulfate hydrate of 96.8% purity with recovery rate 97.1% was obtained from Nd-Fe-B magnet scrap by the fractional crystallization of metal sulfates with addition of ethanol as well as H₂S0₄.

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Recently petroleum coke is used as boiler fuel and residuesof the combustion are collected by electrostatic precipitators. About 80% of the electrostatic precipitatorsoot (EP soot) is combustible, and the remaining 20% is non-combustible compounds containing valuable metals such as vanadium and nickel.
The effects of various operating variables on the oil agglomeration of EP soot, such as oil dosage, impeller speed, temperature of suspension, and time ofagglomeration on yield and ash content of the products were studied in a laboratory batch agglomeration cell. Theyield increases and the ash content of the agglomerates decreases with increasing oil dosage, impeller speed and time of agglomeration. From the results, it was concluded that a high energy consumption is required to recover low ash content agglomerates with high yields.
Wet sieve analysis indicated that the ash content of EP soot increases with decreases in particle size. This was simulated using the equation derived from a model of petroleum coke combustion. Separation efficiency of unburned carbon and ash by size fractionation, using laboratory sieves, was higher than that of oil agglomeration. X-ray diffraction patterns of the feed revealed that most peaks are consistent with metal compounds such as FeV₂O₄, Fe₂SiO₄, NiFe₂O₄, MgFeAlO₄, NiSO₄·2H₂O, and CaV₂O₆. Wet magnetic separation was conducted on the-400 mesh sample containing 53.8% ash. Semiquantitative study of the XRD results showed that in the magnetic fraction FeV₂O₄, Fe₂SiO₄, NiFe₂O₄, and MgFeAlO₄contents increase and in the nonmagnetic fraction CaSO₄·1/2H₂O content increases.

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Construction materials in a shutdown nuclear power plant contain radio activated nickel and cobalt in iron alloys such as stainless steel. The separation of nickel and cobalt from the alloy is required to reduce storage volume of the activated materials. In order to obtain fundamental information on the separation of nickel and cobalt from the stainless steel, the extraction method by using metallic tin as a solvent was studied at 1, 673 K. The following results have been obtained.
By addition of tin and silicon to the stainless steel, phase separation to the metallic tin phase and the stainless steel phase dissolving silicon occurs, and the minimum mutual solubility between the two phases was obtained at 23 mass% Si in the stainless steel phase at 1, 673 K. The distribution ratio of nickel in the tin to stainless steel phases decreases extremely from 0.5 to 0.05 with increasing silicon content from 10 to 23 mass% in the stainless steel phase while the distribution ratios of cobalt and iron represent almost 1/10 of the nickel value. The separation coefficient of nickel shows the minimum value of 8 at 23 mass% Si in the Fe-Si phase while cobalt exhibits almost 2 in the experimental composition region. Based on the experimental results, the extraction and separation process for nickel and cobalt by using metallic tin as a solvent is evaluated at 1, 673 K.

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Dissolution of brass was examined in aqueous cupric ammine solutions. Copper and zinc were dissolved easily fromαandα+βbrass at a diffusion-limiting rate. However, the presence of Sn, Fe and Pb in the alloys inhibited the dissolution of copper and zinc. Applicability of selective dissolution of zinc from zinc or Zn-Fe alloy plated steel sheet using aqueous cupric ammine solutions has been investigated for zinc recovery. After 15 min immersion of the steel in an aqueous 0.5 mol dm^-3CuSO₄^-1mol dm^-3 (NH₄) ₂S0₄-5 mol dm_-3NH₃solution at ambient temperature, zinc on zinc plated steel was found to be eliminated completely without dissolution of iron. On the other hand, zinc recovery from the Zn-Fe alloy plated steel decreased slightly to be 90% and the residual amount of zinc corresponded to 1.3 mg per 1 g of steel.

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