The consumption of mineral resources has grown dramatically during the 20th century. This massive increase has caused the problems of resources exhaustion and environmental pollution during the past twenty years. As a result, the necessity of resources recycling rises year by year.
In this paper, 1) definition and signification of resources recycling, 2) history of mineral consumption and perspective of resources supply, 3) relation between social system and resources recycling, 4) examples of machines for resources recycling are outlined.

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There are various viewpoints to put together situations of resource recycling inforeign countries. It was of course impossible to include all the information for resource recycling in this paper, which discusses exclusively the following subjects:
(1) Trends of research study for metals recycling in foreign countries; and,
(2) Trends of activities relating to resource recycling in foreign countries.
First subject includes an outline of the international symposium on recycling of metals in the United States, and future trends on metals recycling.The second subject includes the situation of waste management in the world, an outline of institutions relating to resource recycling, and present trends in foreign countries and the problems in our country on resource recycling.

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A serious problem in industrial waste management is promoting proper disposal. An effective solution to the problem is improvement of management system for industrial waste. Enforcement of some policies for industrial waste are measures to improve the system. Strengthening of management system for industrial waste is promoting resource recycling that competes with waste disposal at all times.
This paper discusses the following subjects:
(1) The present situation of industrial waste management in Japan; and
(2) New strategies and future problems for industrial waste management.
First subject includes an outlook of presentproblems, actual condition of disposal, and standard of disposal for industrial waste. Second subject includes legislation of disposal guidelines, introduction of manifest system, and countermeasure of the Barsel Convention.

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These descriptions about recycling of copper, lead and zinc are respectively summarized as follows:
Copper: One of the problems of copper's recycling is that the cost for collection of scrap copper is very expensive, because copper is diversified into many merchandizes. And as the value of copper is unstable, it is difficult to get the stable collection continuously.
Lead: The increasing tonnage and percentage of the use for lead-acid batteries were found to be the significant feature. The recycling rate of lead depends much on that of spent lead-acidb atteries. It was concluded that further improvement of the recycling rate would be required especially through the increased collection of spent batteries and treatment in primary lead smelters.
Zinc: The recovery of recycled zinc has been increasing its importance from the viewpoints of resource conservation, pollution control and saving land-fill sites because Japan is quite poor in natural resources.

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Regarding the global environmental problem, increasing fuel efficiency of automobile and reducing car weight have become the target. Aluminium has been getting a big attention for meeting weight reduction as a leading material.
Now in Japan, the secondary aluminium industry produces nearly one-third of aluminium demand of 3.4 million tons per year.
In this paper, raw materials, production technics, quality of products and future prospect of the secondary aluminium industry are discussed.

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Iron is no doubt the most fundamental element to materialize the human society. Present production of iron and steel is about 800 million t in the world and about 100 million t, including 7 million t of cast iron, in Japan. Regarding to recycling, 30% of crude steel is produced utilizing scrap as a secondary sourse of iron. Since the accumulation of the steel in Japan is becoming 1 billion t, the amount of scrap iron will become much larger in the future. Thus, effective smelting and steel making technologies with converter or energy saving electric furnace should be applied to the scrap. On the other hand, the quality of scrap in terms of chemical composition is becoming poorer as the products being needed light and small-sized and having lots of value added. Then the application of precise physical separation becomes important, as well as the development of technological and political system from the view point of the facility of recycling.

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As the rare metals have many advantages in high technology fields, its stable supply for current demands are highly important problems of resources for industrialized country like Japan. Rare metals are condensed as waste or scrap during imports of these metals from aboard. Since these rare metal scraps become urban mineral, development of urban mine will be effective for the stable supply of rare metals.
The present situation of resources such as demand, supply, material production and recycle technology are described for rare metals of titanium, zirconium, vanadium, niobium, tantalum, chromium, molybdenum, tungusten, rare earths, nickel, cobalt, garium, indium and germanium.

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It is important to recycle the elements of gold, silver and the platinum group metals which often put to industrial use for their stability (against heat and chemical reaction), high electroconductivity, and high catalytic activity. This paper deals with recycling techniques of these metals from scaraps containing these elements. These include IC boads, button type batteries containing silver oxide, etc., for gold and silver, and auto exhaust emission control catalysts, precious metal plating chemicals etc., for platinum group, of which the demand seems to be expanded. It also introduces a method proposed by A.J. Gilmore, i.e., goldrecovery from flotation plant effluents with activated charcoal.

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Recycling of nuclear fuel materials is discussed covering from ore to spent fuelthrough nuclear plant operation. Reprocessing of spent fuel is effective for recovering the unused uranium, newly produced pluronium and other valuables such asprecious metals. The hydro process including solvent extraction is operated for reprocessing the spent fuel. The pyro reprocessing process using molten salt system is effective for the metallic fuel reactor. Recycling of nuclear fuel materials are also important for radioactive pollution and waste disposal.
Uraniumand thorium from rare metal ores are condensed in the waste during the ore treatment. Elimination of these nuclear materials from industrial waste is important for metallurgical and chemical industry.

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Application of mercury in Japan has been reduced gradually, still mercury pollution is a world wide problem and the need for recycling of mercury is evident.
The source of mercury recycled are largely classified into the following two: one of them is mercury contained waste such as dry batteries, another one is byproducts such as mercury condensed dust and sludge generated from plant and refining dust collector, scrubber etc.
The roasting process is generally adopted to recover mercury from the wastes and byproducts, and finally harmless disposal or another recycling resources are obtained.
In recycling of mercury as well as toxic and hazardous substances, effort should be focussed on the technology development for environmental protection to reach a social agreement.

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Since the amount of slag generated in ferrous and non-ferrous metals production isconsiderably large, its effective utilization is one of the most significant issues in the industries. Therefore the great effort has beenmade to develop their new applications.In this paper, the current situation and problems on this matter are discussed.In the steel industry, most of ferrous slag is now utilized as a law material for cement production, road construction and so on. Non-ferrous slags are becoming widely used in these days, the usage is however far from satisfactory level in respect both of quantity and price. It is important for these industries to resolve these problems in order to develop new processes or to produce new materials which have higher values added.

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Coal ash produced in Japan has been annually increased because of the energy conversion from oil to coal in electric utilities and industries. Coal ash was produced about 7 million tons in 1989 and estimated as much as 14 million tons in 2, 000. It is necessary to decrease a disposal of coal ash and to promote a effective utilization of it.
This paper shows an overview of the productions, origins and natures of coal ash, and some technological developments for effective utilization of coal ash, such as the manufacturing of artificial lightweight aggregates, artificial potash manure and SO₂ absorbent made from coal ash and lime, and the recovery of metals from coalash.

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Gypsum (CaSO₄·2H₂O) is used as a raw material in the manufacture of Portland cement, gypsum based building product and industrial stucco. Byproduct gypsum, often referred to as synthetic or chemical gypsum, recovered by chemical processing in inorganic and organic industries, has been an important substitutional source. Desulfogypsum is usefully recovered from desulfurization of flue gas from coal or oil-fired boilers and waste gas in copper and zinc smelters. In a broad view, the gypsum industry is a recycling industry. This paper presented the kinds, processes and utilizations of byproduct gypsums.

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Water resources are limited on the globe. Unlike mineral resources, water has aspecial characteristic of being regenerated naturally.
The quantity of water used will increase more in the future and it is thought that Japan's water resources will not be able to adequately satisfy demands, because of the contamination of the many sources of water supply by waste water. There are many pollution sources, such as mining, industrial, agricultural, fisheries, sewage waste waterand etc. Used fresh water can be recycled from sewage water, building waste water, industrial waste water and salt-to-fresh distilled water.
The subject of careful use and recycling of water from now will therefore be important. Thispaper shows water reuse instances.

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Various techniques are applied for the treatment of waste water. This paper shows some examples of valuable recycling from waste metal solutions.
At steel works, a great deal of acid water is employed in pickling line. Acid and iron components are recovered from waste pickling solutions; i.e. iron oxide with thermaldecomposition process, or with wet process; ferrous sulfate with evaporation; and ferric chloride synthesis are introduced.
Considerable amounts of poisonousmaterials such as cyanide and chromic anhydride are used in electroplating factories. Cu, Ag and Au from high concentrated cyanide solutions and of chromic anhydride are recycled from such solutions.

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