钍是一种天然放射性金属,其在地壳中的储量是铀的3倍。钍通常可存在于几种矿石中,其中最常见的是独居石(其中氧化钍的含量可达到12%)。世界各国的钍储量分布情况见表1。表1钍资源分布(可经济开采)国家储量(kt)澳大利亚300印度290挪威170美国160加拿大100南非35巴西16其他国家95 Thorium is a naturally occurring radioactive metal that has three times the amount of uranium in the earth’s crust. Thorium can generally be found in several ores, the most common of which is monazite (with thorium oxide content up to 12%). The distribution of thorium reserves in various countries in the world is shown in Table 1. Table 1 Distribution of thorium resources (economically exploitable) Country reserves (kt) Australia 300 India 290 Norway 170 United States 160 Canada 100 South Africa 35 Brazil 16 Other countries 95