日本の工業原料としての非金属鉱物 (1)
1983 年 92 巻 5 号 p. 344-364
詳細
1983 年 92 巻 5 号 p. 344-364
Non-metallic minerals constitute one of the most important commodities of Japan. Statistics of elemental sulfur production is known since 1905 and that of limestone since 1924, but the annual production of the major non-metallic minerals have been published by the government since around 1950. These statistics show that the production of these minerals grew steadily. The production during the last ten years increased from 147 × 106 tons, 88.3 × 109 yen in 1971 to 210 × 106 tons and 208.6 × 109 yen in 1981. This amounts to an increase of 42 percent in tonnage and 136 percent in value. This is shown together with the change of the value of non-metallic minerals produced in Japan since 1952 in Figure 1.
In Japan, the gravel, crushed stones and building stones are usually treated separately. The total production of non-metallic minerals including the construction materials in 1981 is estimated to be 1170 × 106 tons and 1700 × 109 yen. The production, import and export of the non-metallic minerals of Japan is laid out in Table 4. Large amounts of various types of non-metallic minerals are being imported. The import of 23 major commodities is valued at 240 × 109 yen in 1981 (Table 5).
The non-metallic minerals used for Japanese industry are classified as follows.
A. Materials supplied mostly by domestic production.
1. Minerals supplied mostly from domestic mines ;
limestone, dolomite, white silica-stone, soft silica-stone, refractory silica-stone, aplite, weathered granite, pottery stone, sericite-clay, Gaerome-clay, bentonite, acid-clay, zeolite, bromine, iodine, peridotite-serpentine, sand and gravel, crushed stones, pumice, artificial light-weight aggregate, perlite.
2. Materials supplied mostly by domestic by-products ;
sulphur, gypsum, magnesium-compounds, synthetic gemstone, slag, fly-ash.
B. Materials dependent on import.
1. Minerals with short domestic supply ;
salt, barite, silica-sand, chromite for refractories, industrial diamond (synthetic).
2. Minerals of only high grade imported ;
feldspar, refractory-clay, talc, kaolin, asbestos, diatomite, dimension stone, marble, vermiculite (altered biotite).
3. Minerals totaly dependent on import ;
3-a, Minerals once mined in Japan ;
fluorite, rock-crystal, flint, graphite, phosphate-rock, mica, titanium-minerals.
3-b, Minerals which do not occur in Japan ;
bauxite for refractories, aluminus-shale, kyanite, sillimanite, andalusite, potash minerals, nitrite, strontium-minerals, zircon, boron-minerals, lithium-minerals.
