METHOD FOR SELECTIVE STORAGE OF ROCKS Russian patent published in 1995 - IPC

FIELD: mining of rare-earth element deposits. SUBSTANCE: placed into base of dump is impervious rock layer 3. Then, placed in succession on upper bench 1 and slope part of rocks 4 with low-content of rare-earth elements, and on horizontal part, are, substandard ores 5 containing, mainly, light rear-earth elements. Placed on lower bench 2 are substandard yttrium-containing ores 6. Installed in dump mass are perforated pipes 7 and 8. Side surfaces of dump are screened with impervious layer 9 in which bypass slots 10 and 11 are made. Dump surface is treated with water from source 12. In so doing, rare-earth elements in rocks of dump part 4 are dissolved and migrate to part 5 where due to reaction with gaseous hydrogen chloride fed into perforated pipes 7, crystals of light rare-earth elements are formed. Remained in solution is yttrium chloride which through bypass slots 10 gets into part 6 and is mixed with aqueous solution of ammonia fed through perforated pipes 8 that results in precipitation of yttrium hydroxide. EFFECT: higher quality of stored rocks. 3 cl, 1 dwg