Processing of sulfate and/or sulfide-rich waste using CO2-enriched gases to sequester CO2, reduce environmental impacts including acid rock drainage and produce reaction products
AssigneeStrategic Metals Ltd.
InventorWilliam Douglas Eaton
Life of this patent
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Abstract
A process is provided for stabilizing a sulfate and/or sulfide-rich waste material, comprising metal sulfide minerals, and sequestering CO2 comprises exposing the material to a CO2-enriched gas mixture, reacting the CO2-enriched gas mixture with the metal sulfide minerals and forming a CO2-depleted gas mixture and a carbon-containing compound and at least one product selected from the group consisting of a purified metal or a metal-rich compound suitable for smelting or refining, sulfuric acid, sulfur and sulfurous acid, and system and apparatus therefor.
Claims21
A process for stabilizing a waste material rich in a metal-sulfate compound and/or rich in a metal-sulfide compound which comprises:
- exposing the waste material to a CO2-enriched gas mixture,
- reacting the CO2-enriched gas mixture with the metal-sulfate and/or metal-sulfide compound;
- and
- forming a CO2-depleted gas mixture and a carbonate-containing compound and at least one product selected from the group consisting of a purified metal or a metal-rich compound suitable for smelting or refining, sulfuric acid, sulfur, hydrogen sulfide, sulfur dioxide, sulfur trioxide and sulfurous acid.
A process for stabilizing a waste material rich in a metal-sulfate compound and/or rich in a metal-sulfide compound which comprises:
- (a) contacting the waste material comprising the metal-sulfate compound and/or the metal-sulfide compound with a CO2-enriched gas mixture in a reaction zone to produce a reaction mixture;
- (b) recovering from the reaction mixture metal by-products;
- and
- (c) separating and recovering one or more of sulfuric acid, sulfur, hydrogen sulfide, sulfur dioxide, sulfur trioxide and sulfurous acid from the reaction mixture.
An apparatus for processing mine and industrial waste materials rich in a metal-sulfate compound or rich in a metal-sulfide compound, said apparatus comprising:
- (a) a reactor/reaction zone comprising mine or industrial waste material, wherein the waste material comprises at least one of crushed or ground waste rock, dry tailings, wet tailings, ore stockpiles, or other sulfate-rich and/or sulfide-rich waste materials;
- (b) a feed line into the reactor/reaction zone, for delivery of a CO2-enriched gas mixture;
- (c) a feed line for water and other reactants;
- and
- (d) means to separate solid and liquid reacted products.
A system for stabilizing a waste material rich in a metal-sulfate and/or rich in a metal-sulfide compound and adapted to contain an in situ process, wherein a reaction zone is a contained in situ waste site, said system comprising:
- (a) a source of sulfide-rich mine or industrial waste material rich in a metal-sulfate and/or rich in a metal-sulfide, said source being located in one of i) a heap and ii) pile on a non-permeable liner;
- (b) a series of pipes/lined trenches for draining a reacted liquid product off the non-permeable liner;
- (c) a vessel for storing reacted liquid product;
- (d) a cap/cover to trap injected gas;
- (e) a source of a CO2-enriched gas mixture;
- (f) water and other reactants;
- (g) a pipe system beneath the cap/cover to distribute water and reactants on the heap/pile;
- and
- (h) a pipe system to inject the CO2-enriched gas mixture into the waste material wherein CO2-enriched gas mixture may combine with the waste material, water and other reactants.
A process for stabilizing a waste material rich in a metal-sulfate and/or rich in a metal-sulfide compound which comprises:
- exposing the waste material to a CO2-enriched gas mixture in a reactor/reaction zone, wherein said reactor/reaction zone comprises at least two counter-current cells and wherein waste material, reagents and/or water flow into a first cell in sequence, then proceed onwards in a first direction through a series of latter cells to a last cell and wherein CO2-enriched gas mixture flow in a second opposite direction in counter-current to the first direction, such that CO2-enriched gas mixture enters the last cell and proceeds to the first cell, said process forming a CO2-depleted gas mixture and a carbonate-containing compound and at least one product selected from the group consisting of a purified metal or a metal-rich compound suitable for smelting or refining, sulfuric acid, sulfur, hydrogen sulfide, sulfur dioxide, sulfur trioxide and sulfurous acid.
A process for sequestering CO2, comprising:
- providing a material comprising a metal-sulfate compound and/or a metal-sulfide compound;
- exposing the material to a CO2-enriched gas mixture comprising CO2 to be sequestered;
- reacting the CO2-enriched gas mixture with the metal-sulfate and/or metal-sulfide-rich compound;
- and
- forming a CO2-depleted gas mixture and a carbonate-containing compound and at least one product selected from the group consisting of a purified metal or a metal-rich compound suitable for smelting or refining, sulfuric acid, sulfur, hydrogen sulfide, sulfur dioxide, sulfur trioxide and sulfurous acid.
Dependencies are inferred from the claim text.