Systems and methods for direct oxide production
AssigneeAqua Metals Inc.
InventorsBrian James Dougherty, Samaresh Mohanta, Benjamin Sol Taecker, David Regan
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Abstract
Lead oxide particles are produced in a ball mill or Barton pot-type process from a lead product formed by an electrolytic process that continuously generates metallic lead. The lead product may be in form of lead flakes, spongy lead, or a nano- and/or microcrystalline lead matrix that is directly obtained from the electrolytic process, optionally washed, and may be compressed before being fed to the ball mill or Barton pot-type process. Notably, thusly produced lead oxide particles have desirable purity and size distribution, despite the presence of residual aqueous solution from the electrolytic process that produced the feedstock for the ball mill or Barton pot.
Claims20
A method of producing lead suboxide, comprising:
- producing at a cathode of an electrolytic reactor metallic lead from an aqueous lead ion-containing electrolyte, wherein the metallic lead is formed in form of lead flakes, spongy lead, or a nano- and/or microcrystalline lead matrix and wherein the metallic lead contains some of the aqueous lead ion-containing electrolyte;
- harvesting the metallic lead from the electrolytic reactor,
- removing at least a portion of the aqueous lead ion-containing electrolyte from the metallic lead to form a lead feedstock comprising the aqueous lead ion-containing electrolyte in an amount of at least 1 wt %, wherein the aqueous lead ion-containing electrolyte comprises an impurity, and optionally wherein the impurity comprises a sulfurous compound;
- feeding the lead feedstock into an oxidation device and operating the oxidation device under conditions that form the lead suboxide in particulate form and oxidizes the impurity;
- wherein the lead suboxide comprises a plurality of lead oxide particles and a plurality of metallic lead particles that have a size and composition suitable for use in lead acid battery active materials and wherein the lead suboxide comprises the impurity in an amount of less than 0.01 wt. %;
- wherein the plurality of metallic lead particles and the lead oxide particles have an average particle size of 1-500 microns at a purity of at least 99%;
- and
- removing at least some of the lead suboxide from the oxidation device.
A method of producing lead suboxide having a purity of at least 99%, comprising:
- producing at a cathode of an electrolytic reactor metallic lead from an aqueous lead ion-containing electrolyte, wherein the metallic lead is formed in form of lead flakes, spongy lead, or a nano- and/or microcrystalline lead matrix and wherein the metallic lead contains some of the aqueous lead ion-containing electrolyte;
- removing at least a portion of the aqueous lead ion-containing electrolyte from the metallic lead to thereby form a lead feedstock for a ball mill, wherein the lead feedstock comprises the aqueous lead ion-containing electrolyte in an amount of at least 1 wt %, wherein the aqueous lead ion-containing electrolyte comprises an impurity, and optionally wherein the impurity comprises a sulfurous compound;
- feeding the lead feedstock into the ball mill, and operating the ball mill at a temperature and time that forms the lead suboxide and oxidizes the impurity, wherein the lead suboxide comprises a plurality of lead oxide particles and a plurality of metallic lead particles and wherein the lead suboxide comprises the impurity in an amount of less than 0.01 wt. %;
- and
- removing at least some of the lead suboxide from the ball mill.
A method of producing lead suboxide having a purity of at least 99%, comprising:
- producing at a cathode of an electrolytic reactor metallic lead from an aqueous lead ion-containing electrolyte, wherein the metallic lead is formed in form of lead flakes, spongy lead, or a nano- and/or microcrystalline lead matrix and wherein the metallic lead contains some of the aqueous lead ion-containing electrolyte;
- removing at least some of the aqueous lead ion-containing electrolyte from the metallic lead to thereby form a lead feedstock for a Barton pot process, wherein the lead feedstock comprises the aqueous lead ion-containing electrolyte in an amount of at least 1 wt %, wherein the aqueous lead ion-containing electrolyte comprises an impurity, and optionally wherein the impurity comprises a sulfurous compound;
- melting the lead feedstock to form a liquid lead feedstock;
- oxidizing at least a portion of the liquid lead feedstock in a Barton pot process to form lead suboxide and oxidize the impurity, wherein the lead suboxide comprises a plurality of lead oxide particles and a plurality of metallic lead particles and wherein the lead suboxide comprises the impurity in an amount of less than 0.01 wt. %;
- and
- removing at least some of the lead oxide particles from the Barton pot process.
Dependencies are inferred from the claim text.