Since the geological exploration of uranium deposits was carried out in China from 65438 to 0955, the main types of uranium deposits have been discovered:

1) Granite type This type is mainly distributed in Taoshan-Zhuguangshan metallogenic belt, and it is mostly related to Yanshanian granite in space and genesis. Uranium mineralization mostly occurs in low-grade structures with structural faults, among which silicate monouranium deposits containing pitchblende and crystalline uranium are the main ones. Followed by silicate uranium-lead-zinc deposits containing pitchblende and fluorite.

2) This type of volcanic deposits are mainly distributed in the Jiangxi-Hangzhou metallogenic belt, and the metallogenic ages are mostly Jurassic and Cretaceous. The ore-bearing rocks are lava, subvolcanic rocks and pyroclastic rocks. Mineralization is controlled by regional faults and volcanic structures. Uranium amphibole mainly consists of pitchblende and silicate single mineral deposits. In addition, there are some silicate uranium thorium deposits and uranium copper deposits containing more ilmenite, uranium ore and thorium uranium.

3) Sandstone-type deposits occur in Mesozoic and Cenozoic, in feldspar-bearing, chronological sandstone, granite sandstone and glutenite, and a few are siltstone and mudstone. Rocks usually contain some organic matter and pyrite. The deposits are mainly pitchblende-bearing uranium deposits and uranium-adsorbing silicate-type uranium deposits, followed by pitchblende-bearing carbonate-type uranium-copper deposits.

4) This kind of Carboniferous-siliceous mudstone deposit has complex ore-bearing rocks and is generally rich in organic matter, argillaceous and pyrite. Uranium mainly exists in adsorption state. There are Sinian-Cambrian carbonaceous siliceous mudstone deposits containing pitchblende and Devonian silicate and carbonate uranium molybdenum deposits controlled by structure.

5) Uranium-bearing deposits mainly occur in inferior coal and clastic rocks in Mesozoic and Cenozoic continental basins, and are distributed in western Yunnan and northwest China. The deposit is controlled by lithology, including uranium-bearing coal type and uranium-germanium coal type.

6) Other types include carbonate, alkaline, quartzite and phosphorite.

There are four kinds of uranium deposits in China. Among the proven uranium resources, the reserves of various types of deposits account for 38% of granite type, 22% of volcanic type, 19% of sandstone type, 16% of carbonaceous siliceous mudstone type and 5% of other types. Among the mined uranium mines, granite type uranium deposits account for 37% of the total reserves, volcanic type uranium deposits account for 24%, carbonaceous siliceous mudstone type uranium deposits account for 22%, and sandstone type uranium deposits account for 17%.

According to the report statistics of geological reserves of nearly 200 mineral deposits, hundreds of thousands of tons of uranium metal have been proved, of which deposits with metal content of more than 2,000 tons account for 12.9% of the total number of mineral deposits, and the metal content accounts for nearly half; 65,438+0000 ~ 2,000 tons of metals account for 65,438+07.5% and 26% of the total reserves respectively, while 69.6% and 27.2% of the total reserves are less than 65,438+0000 tons. The scale of uranium deposits is generally small, and the reserves of a single deposit rarely exceed 1 10,000 tons (metal). The buried depth of uranium ore bodies is shallow, generally less than 300 meters, and some ore bodies can extend to 800 meters underground.

According to the statistics of uranium geological system 1989, the average grade of the deposit is 0. 1 15%. About half of the deposits in China have a geological grade of 0. 10 ~ 0.20%. Only 6% deposits have an average grade of more than 0.3%, and about 33% deposits have an average grade of less than 0. 1%.

To sum up, China's uranium resources are characterized by many types of mineralization, small scale, shallow burial and low grade.