Chapter 5. Uranium extraction technology from mine and drainage waters of uranium industry wastes. 5.4. Sorbent selection

Present article is devoted to sorbent selection. In sulfuric solutions, the uranium is found as [UO₂(SO₄)₂ ]^4-, which is produced in result of uranium ores leaching by sulfuric acid and the ratio depends on SO₄^2-, UO₂²⁺ concentration and on the ph medium. Thus, the mine waters of Kiik-Tal settlement and the technical waters of Taboshar settlement also contain ions SO₄^2- and UO₂²⁺. In principle, uranium can be absorbed from sulfuric solutions either by cation exchangers or by anion exchangers, which has been proved by practice. Component extraction sorption effectiveness, in case of uranium, is determined by its extraction degree (%), cleaning and concentration. These are the main sorption tasks. The basic requirements for the process are: maximum sorbent capacity and selectivity by good kinetic sorption indicators and uranium regeneration. Minimum required parameters which should be of interest to a production engineer are: sorption capacity, number of sorption stages, one-time sorbent loading, solution contact duration, desorption conditions. All these parameters are directly or indirectly related and reflect the basic physicochemical regularities of sorption statics and kinetics, and also depend a lot on the apparatus process design. Taking all this into account, apricot shells as sorbent was used. Apricot shells are a cheap and accessible material - canning plants' waste in the North of Tajikistan, which compiles hundred tons every year. The swelling ability of shell is 17%. A number of tests were carried out for optimal sorption regime determination.