PROCESS FOR EXTRACTING RARE-EARTH METALS AND YTTRIUM FROM COALS AND ASH-SLAG WASTE MATERIAL OF COAL BURNING Russian patent published in 2007 - IPC C22B59/00 C22B3/06 C22B3/26 

FIELD: hydraulic metallurgy, namely processes for extracting rare and rare-earth metals from natural organic raw materials such as coals and their burning products such as ash-slag waste materials.

SUBSTANCE: method is realized by using nitric acid for leaching. Selective extraction of rare-earth metal nitrates is realized due to extraction with use of organic solutions of tributyl phosphate and due to using part of heat of coal burning for regeneration of nitric acid by thermal decomposition of refined products and contained in them nitrates of potassium, aluminum, iron and other metals.

EFFECT: lowered consumption of reagents (acids) for leaching rare-earth elements from coals or ash-slag waste materials, simplified process for extracting and purifying rare-earth metals after processing leaching solutions.

4 ex