PROCESSES FOR RECOVERING RARE EARTH ELEMENTS AND RARE METALS
There are provided processes for recovering at least one rare earth element. Such processes comprise obtaining an acidic composition comprising (i) at least one rare earth element and optionally at least one rare metal; and reacting the composition with a precipitating agent so as to substantially selectively precipitate a first rare earth element and optionally a first rare metal. For example, various rare earth elements (such as scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, etc) and various rare metals (such as indium, zirconium, lithium, gallium, etc.) can be extracted by using such processes.
1 - 295 . (canceled)
296 . A process for recovering at least one rare earth element, said process comprising:
obtaining an acidic composition comprising (i) at least one rare earth element and optionally at least one rare metal and (ii) at least one iron ion;
at least partially removing, from said acidic composition, said least one iron ion by means of an extracting agent, an ion exchange resin, hydrolysis and/or by reacting said composition with a reducing agent, thereby obtaining a composition having a reduced content in said at least one iron ion; and
reacting said composition having said reduced content in said at least one iron ion with a precipitating agent so as to substantially selectively precipitate a first rare earth element and optionally a first rare metal that are comprised in a so-formed precipitate, and recovering said precipitate.
297 . The process of claim 296 , wherein said acidic composition comprises (i) said at least one rare earth element and optionally said at least one rare metal and (ii) FeCl 3 .
298 . The process of claim 297 , wherein said extracting agent is chosen from tri-butyl phosphate, di-2-ethylhexyl phosphoric acid (HDEHP), bis(2,4,4-trimethylpentyl) phosphinic acid and 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester).
299 . The process of claim 296 , wherein said acidic composition is reacted with Fe(0), thereby obtaining a composition having a reduced content in Fe 3+ .
300 . The process of claim 296 , wherein said first rare earth element is scandium.
301 . The process of claim 300 , wherein said first rare metal is gallium and said first rare metal is substantially selectively precipitated with said first rare earth element.
302 . The process of claim 296 , wherein said precipitating agent is chosen from oxalic acid, NaOH, MgO, CaCO 3 and mixtures thereof.
303 . The process of claim 301 , wherein said precipitating agent is chosen from oxalic acid, NaOH, MgO, CaCO 3 and mixtures thereof.
304 . The process of claim 301 , wherein said precipitating agent is CaCO 3 .
305 . The process of claim 304 , wherein said first rare earth element and said first rare metal are substantially selectively precipitated by maintaining a pH value below 2.
306 . The process of claim 296 , further comprising leaching said precipitate and obtaining a leaching solution, wherein said leaching solution is further extracted with an extracting agent so as to substantially selectively extract said first rare earth element and said first rare metal and obtain a loaded organic phase.
307 . The process of claim 306 , further comprising scrubbing said loaded organic phase with a scrubbing solution so as to recover said first rare earth element and obtained a scrubbed organic phase.
308 . The process of any one of claim 307 , further comprising stripping said scrubbed organic phase with a stripping solution so as to recover said first rare metal.
309 . The process of claim 296 , wherein said process further comprises, pre-treating or treating said acidic composition with an ion exchange resin so as to remove impurities.
310 . The process of claim 302 , wherein said first rare earth element and said first rare metal are substantially selectively precipitated by maintaining Redox potential of about Eh +380 mV.
311 . A process for recovering at least one rare earth element, said process comprising:
obtaining an acidic composition comprising (i) at least one rare earth element and at least one rare metal; and (ii) at least one metal ion;
at least partially removing, from said acidic composition, said least one metal ion by means of an extracting agent, an ion exchange resin, hydrolysis and/or by reacting said composition with a reducing agent, thereby obtaining a composition having a reduced content in said at least one metal ion; and
reacting said composition having said reduced content in said at least one metal ion with a precipitating agent so as to substantially selectively precipitate a first rare earth element and a first rare metal.
312 . The process of claim 311 , wherein said at least one metal ion comprises at least one aluminum ion, at least one zinc ion, at least one copper ion, at least one nickel ion, at least one magnesium ion, at least one titanium ion and/or at least one iron ion.
313 . A process for recovering at least one rare earth element, said process comprising:
obtaining an acidic composition comprising (i) at least one rare earth element and optionally at least one rare metal and (ii) at least one iron ion;
at least partially removing, from said acidic composition, said least one iron ion by means of an extracting agent, an ion exchange resin and/or by reacting said composition with a reducing agent, thereby obtaining a composition having a reduced content in said at least one iron ion; and
reacting said composition having said reduced content in said at least one iron ion with a precipitating agent so as to substantially selectively precipitate a first rare earth element and a first rare metal by maintaining a pH value below 2, wherein said composition having said reduced content in said at least one iron ion being reacted with said precipitating agent so as to obtain a liquid comprising at least one further rare earth element and said precipitate comprising said first rare earth element and said first rare metal, said process further comprising separating said liquid from said precipitate.
314 . The process of claim 313 , wherein said first rare earth element and said first rare metal is/are substantially selectively precipitated by maintaining a pH at a value of about 1 to about 2.
315 . A process for recovering at least one rare earth element, said process comprising:
obtaining an acidic composition comprising (i) at least one rare earth element and at least one rare metal; and
reacting said composition with a precipitating agent so as to substantially selectively precipitate a first rare earth element and a first rare metal that is gallium.