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US 2024/0002973 A1Published application
Integration of carbon sequestration with selective hydrometallurgical recovery of metal values
AssigneeNegative Emissions Materials, Inc.
InventorsJeremy William LEY, David DREISINGER
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Abstract
Processes are provided in which successive steps of hydrometallurgical value extraction may be carried out using the products of carbon capture and an electrolytic reagent-generating process. The electrolytic process provides an acid leachant and an alkali hydroxide, with the alkali hydroxide then available for use either directly as a precipitant in the hydrometallurgical steps, or available for conversion by carbon capture to an alkali metal carbonate that can in turn be used as the precipitant in the selective hydrometallurgical steps.
Claims26
A process for processing a comminuted mineral feedstock, comprising:
- a) leaching metal values from the comminuted mineral feedstock with an acid leachant, to produce a solid siliceous residue and a loaded leach solution;
- b) precipitating iron and/or aluminum from the loaded leach solution with addition of:
- a first alkali metal carbonate precipitant, to produce a carbon dioxide off gas, or,
- a first alkali hydroxide precipitant,
- to produce an Fe/Al depleted solution and an iron and/or aluminum hydroxide or oxide precipitate product;
- c) precipitating nickel and/or cobalt from the Fe/Al depleted solution or from a Ni/Co ion exchange eluant obtained from the Fe/Al depleted solution by selective extraction of nickel and/or cobalt on an ion exchange medium, wherein the precipitating is with addition of:
- a second alkali metal carbonate or bicarbonate precipitant, or,
- a second alkali hydroxide precipitant,
- to produce a Ni/Co depleted solution and a nickel and/or cobalt carbonate or hydroxide precipitate product;
- d) before or after step (c), precipitating iron and/or aluminum and/or manganese from the Ni/Co depleted solution with addition of an oxidant and with addition of:
- a third alkali metal carbonate or bicarbonate precipitant, or,
- a third alkali hydroxide precipitant,
- to produce an Fe/Al/Mn depleted solution and an iron and/or aluminum and/or manganese hydroxide precipitate product;
- e) precipitating magnesium from the Fe/Al/Mn depleted solution with addition of:
- a fourth alkali hydroxide precipitant, or
- a fourth alkali metal carbonate or bicarbonate precipitant,
- to produce a Mg-depleted solution and a magnesium hydroxide or carbonate precipitate product;
- f) subjecting the Mg-depleted solution to an electrolysis process to produce the acid leachant and:
- one or more of the alkali hydroxide precipitants, or
- an alkali hydroxide product.
17 more elements
A process for processing a comminuted mineral feedstock, comprising:
- optionally magnetically separating material from the comminuted mineral feedstock;
- a) leaching metal values from the comminuted mineral feedstock with an acid leachant, to produce a solid siliceous residue and a loaded leach solution;
- optionally subjecting the loaded leach solution to a resin in leach process so as to selectively remove nickel values from the loaded leach solution, to obtain a purified nickel product,
- optionally, washing and/or alkalization of the solid siliceous residue;
- b) precipitating iron and/or aluminum from the loaded leach solution with addition of:
- a first alkali metal carbonate or bicarbonate precipitant,
- to produce a carbon dioxide off gas, or,
- a first alkali hydroxide precipitant,
- to produce an Fe/Al depleted solution and an iron and/or aluminum hydroxide or oxide precipitate product, optionally a hematite product;
- optionally, washing and/or alkalization of the iron and/or aluminum hydroxide precipitate product;
- optionally, adding a hematite seed material to the step of precipitating iron and/or aluminum, and further optionally wherein the iron and/or aluminum hydroxide or oxide precipitate product comprises the hematite seed material;
- c) precipitating nickel and/or cobalt from the Fe/Al depleted solution or from a Ni/Co ion exchange eluant obtained from the Fe/Al depleted solution by selective extraction of Ni and/or cobalt on an ion exchange medium, wherein the precipitating is with addition of:
- a second alkali metal carbonate or bicarbonate precipitant, or,
- a second alkali hydroxide precipitant,
- to produce a Ni/Co depleted solution and a nickel and/or cobalt carbonate or hydroxide precipitate product;
- d) before or after step (c), precipitating iron and/or aluminum and/or manganese from the Ni/Co depleted solution with addition of an oxidant and with addition of:
- a third alkali metal carbonate or bicarbonate precipitant, or,
- a third alkali hydroxide precipitant,
- to produce an Fe/Al/Mn depleted solution and an iron and/or aluminum and/or manganese hydroxide precipitate product;
- optionally recycling a brine comprising the Fe/Al/Mn depleted solution to a comminuting step to provide the comminuted mineral feedstock;
- e) precipitating magnesium from the Fe/Al/Mn depleted solution with addition of:
- a fourth alkali hydroxide precipitant, or
- a fourth alkali metal carbonate or bicarbonate precipitant,
- to produce a Mg-depleted solution and a magnesium hydroxide or carbonate precipitate product;
- f) subjecting the Mg-depleted solution to an electrolysis process to produce the acid leachant and:
- one or more of the alkali hydroxide precipitants, or
- an alkali hydroxide product;
- and,
- g) sequestering carbon dioxide from a CO2 containing gas, by reacting the CO2 containing gas directly or indirectly with the alkali hydroxide product, in one or more of:
- the nickel and/or cobalt carbonate precipitate product;
- or, the magnesium carbonate precipitate product.
28 more elements
Dependencies are inferred from the claim text.