韓半島 沃川帶 炭質泥岩層中의 低品位 우라늄鑛의 賦存狀態 및 우라늄, 바나듐 回收工程開發硏究 (Ⅰ)

Uranium occurrences, and process development for recovering uranium and vanadium from uranium ore in coaly meta-pelites in Ogcheon terrain, Korea (Ⅰ)

Combined mineralogical and geochemical studies were made on two hundred eighty one representative samples from uraniferous coaly meta-pelites of the Ogcheon metamorphic terrain. Different mineral occurrence of the areas investigated should be taken into account for chemical processes for uranium extraction. Secondary uranium minerals identified are metauranocircite, metatorbernite and autunite. These are disseminated mostly on the laumontites which infused and filled secondary openings in the coaly matrix, and are often closely associated with iron oxides. The uranium distribution show distinctly log normal. Geochemical correlation coefficient of uranium and organic carbon displays +0.624~+0.796. The relationship of the major components to uranium can be expressed by the following regression equation: Log(U₃O₈×10⁴)=1.40117-0.00076 (quartz)-0.00118 (muscovite)+0.00235 (biotite)+0.00323 (other silicates)-0.01114 (apatite)+0.01124 (hematite)+0.00149 (limonite)-0.01823 (opaques)+0.03049 (organic carbon). Uranium in the coaly meta-pelites of the Ogcheon Group was deposited together under same physico-chemical environmental conditions. There is a considerable variation in the δ³⁴S values (11.2~16.8 per mil) of the pyrites from the U-bearing meta-pelites, which implies sedimentary origin. The two U-bearing coaly rocks analyzed have δ¹³C values between -16.88~-18.00 per mil, which suggests organic.