National University of Science and Technology "MISIS"

T. V. Bashlykova, Head of Projects

National Research Nuclear University MEPhI

A. V. Valkov, Professor, e-mail: ale1534@yandex.ru

V. I. Petrov, Dean of a Faculty of Physics and Engineering

The extraction process rare-earth elements (REE) from phosphogypsum and kularite waste gold mining was investigated. Kularit,s concentrate with size of grain 0.5–1 mm have following composition (mass %): Si — 3.4%; Th — 0.5%; U <0.1%; REE — 60%. Rare-earth elements were offered, in general, cerium group (mass %): La₂O₃ — 23–24; Ce₂O₃ — 47–48; Pr₂O₃ — 5–6; Nd₂O₃ — 18–20; Sm₂O₃ — 3–4; Eu₂O₃ — 0.4; Gd₂O₃ — 1.1; Dy₂O₃ — 0.25; Ho₂O₃ — 0.03; Er₂O₃ — 0,04, Lu₂O₃ <0.004; Y₂O₃ — 0.6. The mineral by solution sulfuric acid, sodium hydroxide or agglomeration with sodium carbonate under heating was uncovered. The technology of producing a REE-concentrates, including division into groups with reception of concentrates is offered: lanthanum, cerium, samarium-europium-gadolinium and didimium. The concentrate of REE is dissolved in nitric acid and than lanthanum are separated using solvent extraction with 100% TBP. At the first stage cerium is recovered as Ce(IV) from solution using electrochemical process. The residual REE are separated by solvent extraction using cascades, contained 70–80 stages. In Russia the source REE can be phosphogypsum. The phosphogypsum are necessary for examining as complex raw materials and necessity of consumption of all selected соmponents. Peculiarity extraction of REE from phosphogypsum forming in opening apatite by sulphuric acid was studied. The technology of phosphogypsum processing containing extraction REE by sulfuric acid, gypsum treatment by potassium carbonate, allocation and realization of potassium sulfate as effective fertilizer, entire calcium(strontium) carbonates for agriculture and REE for atomic energy was proposed.

1. Patent 2109686 RF. Sposob izvlecheniya redkozemelnykh elementov iz fosfogipsa (The way of rare earth elements extraction from the phosphogypsum). Dmitriev A. O., Yakovleva E. Yu., Shemyakin V. S., Martynov A. I. Asserted 01.02.1996. Published 27.04.1998.

2. Patent 2293781 RF. Sposob izvlecheniya redkozemelnykh elementov iz fosfogipsa (The way of rare earth elements extraction from the phosphogypsum). Lokshin E. P., Kalinnikov V. T., Ivlev K. G. et al. Asserted 04.07.2005. Published 20.02.2007.

3. Patent 2225892 RF. Sposob izvlecheniya redkozemelnykh elementov iz fosfogipsa (The way of rare earth elements extraction from the phosphogypsum). Lokshin E. P., Vershkova Yu. A., Kalinnikov V. T. et al. Asserted 23.07.2002. Published 20.03.2004.

4. Patent 2258036 RF. Sposob kompleksnoy pererabotki fosfogipsa (The way of a complex prosessing of the phosphogypsum). Kolokolnikov V. A., Titov V. M., Shatov A. A. Asserted 23.07.2002. Published 20.03.2004.

5. Patent 2172719 RF. Sposob izvlecheniya redkozemelnykh elementov iz kislykh rastvorov (The way of rare earth elements extraction from the acid solutions). Vershkov A. V., Vershkova Yu. A., Lokshin E. P., Masloboev V. A. Asserted 17.07.2000. Published 27.08.2001.

6. Patent 2158317 RF. Sposob izvlecheniya redkozemelnykh elementov iz fosfogipsa (The way of rare earth elements extraction from the phosphogypsum). Lebedev V. N., Lokshin E. P. Asserted 16.02.1999. Published 27.10.2000.

7. Patent 2104938 RF. Sposob izvlecheniya redkozemelnykh elementov iz fosfogipsa (The way of rare earth elements extraction from the phosphogypsum). Valkov A. V., Valkov D. A. Asserted 26.09.1996. Published 20.02.1998.