Uranium: How is it Mined? Has fulfilled: Muratkhanov Sunggat. - презентация

1 Uranium: How is it Mined? Has fulfilled: Muratkhanov Sunggat

2 Uranium is a chemical element with symbol U and atomic number 92. It is a silvery-white metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weakly radioactive because all isotopes of uranium are unstable, with half- lives varying between 159,200 years and 4.5 billion years. The most common isotopes in natural uranium are uranium-238 (which has 146 neutrons and accounts for over 99%) and uranium-235 (which has 143 neutrons). Uranium has the highest atomic weight of the primordially occurring elements.

3 Among the elements found in the Earth's crust, uranium is the most abundant. About 99.4% of uranium is uranium- 238, the remaining 0.6% is uranium-235, used in the development of nuclear weapons. There are 3 main ways to extract uranium. 1) Outdoor 2) Underground 3) Downhole underground leaching

4 The first method is open, suitable for those cases when the ore body is close to the surface of the earth. With open method of mining, bulldozers dig a large pit and excavators load ore into dump trucks, which take it to the processing complex.

5 The second way - underground - is used when the ore body is deeply buried. This method is more expensive and suitable for a high concentration of uranium in the rock. Under the underground method, a vertical shaft is drilled, from which horizontal excavations go. The depth of the mines can be up to two kilometers. In the horizontal drifts, miners chop the rock, lift the ore upward on special freight elevators and then take them to the processing complex. The rocks are ground, mixed with water and remove unnecessary impurities. Further, the concentrate is leached, usually with sulfuric acid. A precipitate of uranium salts with a characteristic yellow color is released from the solution with the help of ion-exchange resins, for which they were called yellow cake. The yellow cake still contains quite a lot of impurities, from which it is purified in refining production and after calcination, uranium oxide-uranium (U3O8) is obtained, the final product even traded on the stock exchange.

6 But there is a third way. It is radically different from the first two and is called downhole leaching (SPV). In SPS, 6 wells are drilled at the corners of the hexagon, through which sulfuric acid is pumped into the ore body. In the center of the hexagon, another well is drilled and through it a solution saturated with uranium salts is pumped out to the surface. The productive solution is passed through sorption columns in which the uranium salts are collected on a special resin. The resin, in turn, is again treated with sulfuric acid and so several times until the concentration of uranium in the solution becomes sufficient. And then again the yellow cake, cleaning and getting nitrous oxide- uranium