[en] The paper is analyzed uranium value distribution and ratio of uranium (VI) and uranium (IV) of sandstone-type uranium deposits based on the experimental results about ordinary stirred leaching and simulative in-situ leaching, and the theoretical study by state equation of U (VI) alkali solution. These results show (1) the uranium value distribution from geological reports, is concerned with the ratio of mineral samples, but the uranium ores lied in geological environment conditions; (2) U (IV) minerals could be the only value state about the original uranium value distribution. (authors)

[en] The problems of resin bed harden in C0₂ + O₂ in-situ leaching process affected the stability and continuity of the process. Reries of exploratory research were carried out for the reason. At first, By analyzing the harden materials which came from in-situ leaching solution, it was found that the harden materials were formed by the humic organic matter adhering to the surface of silt. Secondly, the water quality parameters of leaching solution and resin adsorption, such as COD and TOC, were tested in Tongliao test field. It was found that values of COD and TOC in tail liquid adsorption were lower than the values in original leaching solution. COD and TOC are two important indicators of the content of organic matter in water. The results of characterization showed that, the organic matter in leaching solution was an important reason which caused the resin bed harden. That the organic matter attached to the surface of sediment deposited on the surface of resin particles, or organic matter sticked together between resin particles, would make the resin bed harden. (authors)

[en] Based on the investigation of the mineral form and chemical compositions, the processing method and leaching parameters were selected through acid stirring leaching, alkaline stirring leaching and acid column leaching experiments. Under suitable conditions, the leaching rate of acid stirring leaching can reach 88.44%, and leaching rate of acid column leaching is 87.65%. Alkaline stirring leaching is not suitable for the ore for its low leaching rate. In the final analysis acid heap leaching is available for extracting uranium from the uranium ore in the industrial production. (authors)

[en] Uranium minerals of a uranium ore in Jiangxi province and its composition were investigated. Baesd on the investigation, the processing method and leaching parameters were selected through experiments. (authors)

[en] Compositions of waste water from a uranium tailings pond and main pollution factors were analyzed. A method of treating the waste water was determined through experiments, that is, neutra-lization with milk of lime-adsorption with manganese sand method, and the waste water was treated by the method. Contents of U, Ra and Mn, and pH value in the treated waste water meet the national discharge standard. (authors)

[en] The twice 4 elements tracing contrast tests were conducted before and after micro-acidification at a testing site of in-situ leaching uranium. Through establishment different solute migration models before and after acidification, the influence of acidification on leaching is quantitatively analysed. Simulation results show that after acidification of the well site of in situation leaching of uranium, the effective area of convection and leaching range are increased 3.5 times and 3.2 times respectively compared with the un-acidified tests;micro-acidification is benefit to increase the efficiency of in-situ leaching uranium. (authors)

[en] Methods of static adsorption and dynamic adsorption are used to study the adsorption of uranium-bearing pit water on ion exchange fibre. The effects of contact time, height of ion exchange fibre column,and balance of uranium between aqueous phase and fibre phase are investigated. It is indicated that ion exchange fibre presents advantages such as fast adsorption, fast elution, same capacity compared with ion exchange resin. 106 g/L Na₂CO₃+5 g/L NaHCO₃ is a suitable eluant for ion exchange fibre. Therefore ion exchange fibre can be selected to process uranium-bearing pit water. (authors)

[en] Chemical analysis has been carried out to get the characteristics of the ore sample from some uranium mine in Inner Mongolia. Based on the characteristics, acid leaching, alkaline leaching and neutral leaching experiments have been executed to find out the leaching feasibility of the uranium mine with in-situ leaching technology. Further resource recovery study is proposed with neutral leaching method for the mine. (authors)

[en] MnO₂, MnO₂+FeSO₄ and Fe₂(SO₄)₃ are used respectively as oxidant for acid leaching of a uranium ore after gravity dressing. The results indicate that Fe₂(SO₄)₃ can obviously reduce the consumption of H₂SO₄ and accelerate leaching rate with lower temperature. The leachate with Fe₂(SO₄)₃ has lower concentration of P and Mn. (authors)

[en] Due to the advantages of low chemical reagent consumption and less environment pollution, C0₂ + 0₂ in-situ leaching process bas been applied widely in uranium mines at home and abroad. C0₂ + 0₂ leaching test had been carried out since 2000 in Xinjiang and the same in-situ leaching field test began in 2012 in Ordos basin. It is shown that injection volume of injection wells decreased gradually at the beginning of this test. This paper discussed the main formation mechanism of injection wells colmatation and analyzes the influence factors. Based on SI saturation index method, it identified that CaC0₃ colmatation is the important reason for injection volume decreasing. C0₂ is added to the lixiviant so as to reduce both pH and SI value. As a result, CaC0₃ colmatation has been dissolved and the injection volume of injection wells increased soon afterwards. (authors)