PTAB

IPR2019-01603

EnergySource Minerals LLC v. TErrALithium LLC

Log In
Key Events
Petition
petition Intelligence

1. Case Identification

2. Patent Overview

  • Title: Treated Geothermal Brine Compositions with Reduced Concentrations of Silica, Iron, and Zinc
  • Brief Description: The ’126 patent is directed to treated geothermal brine compositions having reduced concentrations of silica, iron, and zinc. The compositions are intended to prevent scale buildup in geothermal power plants, improve brine injectivity after mineral extraction, and facilitate the recovery of valuable metals such as lithium.

3. Grounds for Unpatentability

Ground 1: Anticipation by Christopher - Claims 1-20 are anticipated under 35 U.S.C. §102 by Christopher.

  • Prior Art Relied Upon: Christopher (a 1975 Bureau of Mines publication detailing mineral recovery from geothermal brines).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Christopher discloses every element of the challenged claims by describing the treatment of Sinclair No. 4 well brine, a Salton Sea geothermal brine. Petitioner asserted that Christopher's process yields a "treated geothermal brine" with reduced concentrations of zinc, iron, and silica that fall within the claimed ranges of the ’126 patent. Specifically, data in Christopher's tables and figures showed post-treatment zinc concentrations of 3.4 mg/kg and 5.0 ppm, iron concentrations of 4.5 mg/kg and 1.0 ppm, and a post-flash silica concentration of 40 ppm. Christopher also disclosed recoverable amounts of lithium (e.g., 221 mg/kg), satisfying all limitations of independent claim 1 and its dependent claims.
    • Key Aspects: Petitioner contended that Christopher's process, which involves aeration and pH control with lime, would inherently cause iron to co-precipitate with silica. This chemical process would necessarily reduce silica concentrations to levels that anticipate the claims, even beyond the explicitly stated 40 ppm value.

Ground 2: Obviousness over Christopher Combination - Claims 1-20 are obvious under 35 U.S.C. §103 over Christopher in view of Brown, Burrows, and/or Wilkins.

  • Prior Art Relied Upon: Christopher (1975 publication), Brown (Patent 5,358,700), Burrows (’749 application), and Wilkins (Patent 4,016,075).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that to the extent Christopher alone was found not to teach the claimed low silica concentrations, the secondary references explicitly remedy this. Brown teaches removing silica to less than 10 ppm to minimize scaling for reinjection. Burrows discloses a method to reduce residual silica concentrations to 1 ppm or less. Wilkins teaches a process that reduces dissolved silica to about 10 ppm or less. A Person of Ordinary Skill in the Art (POSITA) would apply these known silica-reduction techniques to the brine treatment process described in Christopher.
    • Motivation to Combine: A POSITA would combine Christopher's general brine treatment process with the specific silica removal techniques of the secondary references to solve the well-known and persistent problems of scaling on processing equipment and fouling of injection wells. This combination was argued to be a predictable solution to improve the overall efficiency and economics of mineral extraction from geothermal brines.
    • Expectation of Success: A POSITA would have a high expectation of success in achieving the claimed low silica levels. The secondary references were presented not as theoretical concepts, but as established art demonstrating that silica concentrations of 1-10 ppm were practically achievable in geothermal brines.

Ground 3: Anticipation by Maimoni - Claims 1-20 are anticipated under 35 U.S.C. §102 by Maimoni.

  • Prior Art Relied Upon: Maimoni (a 1982 Lawrence Livermore Laboratory report on mineral recovery from Salton Sea brines).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner contended that Maimoni independently anticipates the claims by describing a cementation process for mineral recovery. Petitioner pointed to a process flow table in Maimoni that disclosed a treated brine stream with a zinc concentration of 17 ppm, an iron concentration of 13 ppm, and recoverable lithium of 182 ppm. While silica was reported at 22 ppm in an upstream process flow, Petitioner argued this inherently results in a final concentration of less than or equal to 22 ppm. These disclosed values fall within the claimed ranges of claim 1.
    • Key Aspects: Similar to the Christopher argument, Petitioner asserted that Maimoni's disclosed process—adding calcium hydroxide and aerating the brine—would inherently cause co-precipitation of silica with iron. This would drive the final silica concentration well below the reported 22 ppm, thereby anticipating the claimed ranges.

  • Additional Grounds: Petitioner asserted additional challenges, including inherency and obviousness over Christopher alone; inherency and obviousness over Maimoni alone; and obviousness over Maimoni in view of Christopher, Brown, Burrows, and/or Wilkins.

4. Key Claim Construction Positions

  • Petitioner argued that claim limitations reciting concentration ranges with a lower limit of "0" (e.g., "silica ranging from 0 to 80 mg/kg") or using the phrase "less than" must be construed as rendering that component optional for infringement and validity analyses.
  • Citing MPEP guidance and case law, Petitioner asserted that if a component can be present at a concentration of zero, its presence is not a required element of the claim. This construction was central to the anticipation arguments, as it would allow a prior art reference that teaches the complete removal of a component like silica to meet the claim limitation.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-20 of Patent 9,644,126 as unpatentable.