DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-6, 8, 11, and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Slatin (US 2,961,387 A) in view of Seon et al (US 5,190,625 A).
Slatin teaches (see col. 1, lines 15-19, Example III in col. 7) a method of preparing rare earth metals. The method was implemented by using an electrolytic cell divided into an anode chamber and a cathode chamber, wherein an anolyte and an anode were provided in the anode chamber and a catholyte and a cathode were provided in the cathode chamber. The bottom of the electrolytic cell contained a liquid alloy in contact with the anolyte and catholyte, which were separated from each other by a dependent baffle. The method comprised powering on the electrolytic cell to operate, adding a rare earth compound (per Example III, rare earth chloride was added, but col. 4, lines 13-22 teach that oxides may be used in place of the chlorides) to the anode chamber and obtaining a rare earth product in the cathode chamber.
Slatin fails to teach that the cathode is a solid consumable cathode or a liquid cathode nor that the rare earth was recovered as a liquid alloy product.
In the same field of endeavor of electrolytic recovery of rare earth metals, Seon et al teach (see abstract, col. 2, lines 17-32, and col. 3, lines 1-14) that cathodes for recovery of the rare earth metal had several useful forms depending upon the final preparation of the metal. When the rare earth metal was to be recovered as an alloy, such as an alloy of the rare earth with iron, cobalt, nickel, or chromium, the cathode was a solid consumable material of the alloying element. The electrolytic process directly formed the alloy without having to perform a separate alloying step.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have utilized a solid consumable cathode as taught by Seon et al in the process of Slatin for the purpose of permitting direct production of a rare earth alloy comprising the rare earth and the metal of the consumable cathode as suggested by Seon et al without having to perform a separate alloying step.
Regarding claim 2, Slatin teaches forming yttrium from a pure anhydrous starting compound, such that one of ordinary skill in the art at the time of filing would have expected the raw material to comprise at least 90wt% (e.g. at least 99wt% of the yttrium compound).
Regarding claim 3, Slatin and Seon et al teach that the electrolytic recovery of the rare earth metal produced a high level of purity of the metal.
Regarding claim 4, the anode of Slatin was a carbon anode (graphite).
Regarding claim 5, Slatin teaches the liquid alloy comprising the rare earth metal and copper. As evidenced by the catholyte and anolyte floating on top of the liquid alloy, the liquid alloy is considered to inherently have a density greater than either of the anolyte or the catholyte.
Regarding claim 6, Slatin teaches the anolyte comprising a chloride system comprising CaCl2 with CaF2.
Regarding claim 8, the metal (e.g. nickel) of the consumable cathode of Seon et al possessed a melting point higher than the electrolysis temperature and the metal formed an alloy with the rare earth metal that had a melting point lower than the electrolysis temperature. During normal operation, Slatin teaches (see Table 4) that the cathode current density was 29.4 amp/in2 (~4.5 amp/cm2).
Regarding claim 11, Seon et al teach (see col. 2, lines 28-32) the metal (M1) being iron (Fe), cobalt (Co) or nickel (Ni).
Regarding claim 13, Slatin teaches the anolyte comprising a chloride system comprising CaCl2 with CaF2.
Claims 7 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Slatin (US 2,961,387 A) in view of Seon et al (US 5,190,625 A) as applied to claims 1 and 5, respectively, above, and further in view of Shedd et al (“Electrowinning Misch metal from a Treated Bastnasite Concentrate”, U.S. Bureau of Mines R.I.7398).
Slatin teaches a catholyte comprising a mixture of LiCl and rare earth (yttrium) chloride.
The catholyte of Slatin is not taught as comprising 40-90 wt% of the rare earth fluoride, 10-50 wt% LiF and 0-30 wt% BaF2 or CaF2.
Shedd et al teach (see abstract and Determination of Optimum Electrolyte Composition on pages 7-8) an electrolytic bath suitable for electrolytic recovery of rare earth metals at a cathode, wherein the optimal bath composition was determined to be 50 wt% of rare earth fluorides, 30 wt% LiF, and 20 wt% BaF2. This bath allowed high current while avoiding precipitation of a second phase.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have substituted the fluoride-based electrolytic bath taught by Shedd et al in place of the catholyte composition taught by Slatin because the bath composition taught by Shedd et al permitted high current (i.e. faster metal production rate) while also avoiding undesirable precipitation of compound from the bath.
Claims 10 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Slatin in view of Seon et al (US 5,190,625 A) as applied to claim 1 above, and further in view of Morrice et al (“Preparation of Rare-Earth and Yttrium Metals by Electrodeposition and Vacuum Distillation of Alloys”, U.S. Bureau of Mines R.I.7308).
Seon et al teach forming the rare earth alloy product as a liquid.
However, neither Slatin nor Seon et al teach that the liquid rare earth alloy product was subjected to a refining process to recover high-purity rare earth metal/alloy materials.
Morrice et al teach (see abstract, Vacuum Distillation section on pages 5-6) that rare earth alloys that are recovered via electrodeposition may be subjected to a further refining process, such as vacuum distillation, to separate and recover high purity individual rare earth metals.
Note that there is substantial overlap in rare earth alloy product being recovered in Seon et al, where the non-rare earth alloying element was iron, cobalt, nickel, and chromium, and Morrice et al, where the non-rare earth alloying elements was iron, manganese, or chromium.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have recovered the liquid rare earth alloy product of Slatin as modified by Seon et al and to have utilized the alloy product in the conventional vacuum distillation process as taught by Morrice et al for the purpose of recovery multiple different rare earth metals in a high purity state as taught by Morrice et al.
Claims 1-6, 9, 12, and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Slatin (US 2,961,387 A) in view of Claus et al (US 5,118,396 A).
Slatin teaches (see col. 1, lines 15-19, Example III in col. 7) a method of preparing rare earth metals. The method was implemented by using an electrolytic cell divided into an anode chamber and a cathode chamber, wherein an anolyte and an anode were provided in the anode chamber and a catholyte and a cathode were provided in the cathode chamber. The bottom of the electrolytic cell contained a liquid alloy in contact with the anolyte and catholyte, which were separated from each other by a dependent baffle. The method comprised powering on the electrolytic cell to operate, adding a rare earth compound (per Example III, rare earth chloride was added, but col. 4, lines 13-22 teach that oxides may be used in place of the chlorides) to the anode chamber and obtaining a rare earth product in the cathode chamber.
Slatin fails to teach that the cathode is a solid consumable cathode or a liquid cathode nor that the rare earth was recovered as a liquid alloy product.
In the same field of endeavor of electrolytic recovery of rare earth metals (neodymium specifically), Claus et al (see abstract) that a liquid magnesium cathode may be used to recover neodymium from a molten salt containing a dissolved salt of neodymium to form a liquid magnesium-neodymium alloy product. The electrolytic process using the liquid magnesium cathode prevented (see col. 1, lines 43-54) redissolution of the neodymium back into the electrolyte thereby improving efficiency.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have utilized a liquid cathode as taught by Claus et al in the process of Slatin for the purpose of preventing redissolution of the recovered rare earth into the electrolyte to improve efficiency as taught by Claus et al.
Regarding claim 2, Slatin teaches forming yttrium from a pure anhydrous starting compound, such that one of ordinary skill in the art at the time of filing would have expected the raw material to comprise at least 90wt% (e.g. at least 99wt% of the yttrium compound).
Regarding claim 3, Slatin and Claus et al teach that the electrolytic recovery of the rare earth metal produced a high level of purity of the metal.
Regarding claim 4, the anode of Slatin was a carbon anode (graphite).
Regarding claim 5, Slatin teaches the liquid alloy comprising the rare earth metal and copper. As evidenced by the catholyte and anolyte floating on top of the liquid alloy, the liquid alloy is considered to inherently have a density greater than either of the anolyte or the catholyte.
Regarding claim 6, Slatin teaches the anolyte comprising a chloride system comprising CaCl2 with CaF2.
Regarding claims 9 and 12, the liquid cathode of Claus et al was a metal (M2=magnesium), wherein the melting point of M2 was lower than the electrolysis temperature and M2 was allowed to form an alloy with the rare earth metal. During normal operation, Slatin teaches (see Table 4) that the cathode current density was 29.4 amp/in2 (~4.5 amp/cm2).
Regarding claim 13, Slatin teaches the anolyte comprising a chloride system comprising CaCl2 with CaF2.
Claims 7 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Slatin (US 2,961,387 A) in view of Claus et al (US 5,118,396 A) as applied to claims 1 and 5, respectively, above, and further in view of Shedd et al (“Electrowinning Misch metal from a Treated Bastnasite Concentrate”, U.S. Bureau of Mines R.I.7398).
Slatin teaches a catholyte comprising a mixture of LiCl and rare earth (yttrium) chloride.
The catholyte of Slatin is not taught as comprising 40-90 wt% of the rare earth fluoride, 10-50 wt% LiF and 0-30 wt% BaF2 or CaF2.
Shedd et al teach (see abstract and Determination of Optimum Electrolyte Composition on pages 7-8) an electrolytic bath suitable for electrolytic recovery of rare earth metals at a cathode, wherein the optimal bath composition was determined to be 50 wt% of rare earth fluorides, 30 wt% LiF, and 20 wt% BaF2. This bath allowed high current while avoiding precipitation of a second phase.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have substituted the fluoride-based electrolytic bath taught by Shedd et al in place of the catholyte composition taught by Slatin because the bath composition taught by Shedd et al permitted high current (i.e. faster metal production rate) while also avoiding undesirable precipitation of compound from the bath.
Claims 10 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Slatin in view of Claus et al (US 5,118,396 A) as applied to claim 1 above, and further in view of Morrice et al (“Preparation of Rare-Earth and Yttrium Metals by Electrodeposition and Vacuum Distillation of Alloys”, U.S. Bureau of Mines R.I.7308).
Claus et al teach forming the rare earth alloy product as a liquid alloy with magnesium. Claus et al further teach (see fig. 2, col. 5, lines 10-25) performing a refining process comprising distillation to recover high purity neodymium.
However, Claus et al fail to teach the distillation process being vacuum distillation.
Morrice et al teach (see abstract, Vacuum Distillation section on pages 5-6) that rare earth alloys that are recovered via electrodeposition may be subjected to a further refining process, such as vacuum distillation, to separate and recover high purity individual rare earth metals.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have utilized the known vacuum distillation process taught by Morrice et al as the refining process of Claus et al for the purpose of recovery multiple different rare earth metals in a high purity state as taught by Morrice et al.
Conclusion
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/HARRY D WILKINS III/Primary Examiner, Art Unit 1794
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