Methods of recycling metallic ion content from inorganic solids and systems thereof

Abstract

Provided herein are method of recycling metallic ion content from inorganic solid and systems thereof. The methods and systems include contacting inorganic solid with an acid to produce said concrete precursors.

Description

METHODS OF RECYCLING METALLIC ION CONTENT FROM INORGANIC SOLIDSAND SYSTEMS THEREOFTECHNICAL FIELD

[0001] The present disclosure generally relates to methods of reducing metallic ion content in inorganic solids.BACKGROUND

[0002] Human produce massive amounts of inorganic waste. This waste is high- volume, persistent, and often contains extensive amounts of metals that can be toxic. Such waste is produced from several sources including consumer electronics, in particular battery recycling where mixed metals and metal oxides are challenging to recover, and also from metal fabrication and other common industrial processes. For example, during the forming and heat treatment process of stainless steel, a layer of black oxide skin is generated on the surface, the structure of the oxide skin is compact, the aesthetic property of the surface of the steel is damaged, the electrochemical corrosion of the metal surface is accelerated, and the stress corrosion of the surface of the steel is accelerated due to the existing surface stress. The scale on the surface of the stainless steel must be removed before subsequent processing, typically via steel ‘‘pickling"’.

[0003] Technological innovation and market expansion continue to drive the turnover of electronic devices. This development leads to an important increase in waste electrical and electronic equipment (WEEE) (e.g., electronics waste).

[0004] There is currently no energy' and cost-efficient process to safely and effectively treat these waste streams.SUMMARY

[0005] Provided herein are methods and systems for recycling metallic ion content from inorganic solids (e.g., steel, smelting slag, blast furnace slag, incinerator bottom ash, and electronics waste). The systems and methods described herein can have several advantages over the conventional methods of making such recycling such materials, including (for example), lower cost and less waste produced, using less energy' (e.g., net energy' neutral), producing less CO2 (e.g., carbon neutral) or even being net carbon negative (e.g., sequestering CO2), and providing a regenerative process to reuse byproducts of the reaction in the reaction.

[0006] In general, this disclosure relates to processes and systems for recycling metallic ion content from inorganic solid.

[0007] Some embodiments provide a method of recycling metallic ion content from inorganic solid, the method comprising:(a) contacting an inorganic solid waste comprising one or more metallic ions with an acid to produce a liquid rich in the one or more metallic ions;(b) contacting the liquid rich in the one or more metallic ions with a base to produce a precipitate comprising the one or more metallic ions and a liquid deficient in the one or more metallic ions;(c) contacting the liquid deficient in the one or more metallic ions with an electrolyzer to regenerate the acid and the base, and(d) repeating each of steps (a)-(b) at least once with the acid and the base from step (c).

[0008] Some embodiments provide a method of recycling metallic ion content from inorganic solid, the method comprising:(a) contacting the inorganic solid comprising one or more metallic ions with an acid to produce a liquid rich in the one or more metallic ions;(b) contacting the one or more liquid rich in the one or more metallic ions with a base to produce a precipitate comprising the one or more metallic ions and a liquid deficient in the one or more metallic ions;(c) contacting the liquid deficient in the one or more metallic ions with an electrolyzer to regenerate the acid and the base, and(d) repeating each of steps (a)-(b) at least once with the acid and the base from step (c).

[0009] Some embodiments provide a method of recycling metallic ion content from inorganic solid, the method comprising:(a) contacting the inorganic solid comprising one or more metallic ions with an acid to produce a liquid rich in the one or more metallic ions;(b) contacting the liquid rich in the one or more metallic ions with a base and carbon dioxide to produce a precipitate comprising one or more metal carbonates from the one or more metallic ions and a liquid deficient in the one or more metallic ions; and(c) contacting the liquid deficient in the one or more metallic ions with an electrolyzer to regenerate the acid and the base.

[0010] Some embodiments provide a method of recycling metallic ion content from inorganic solid, the method comprising:(a) contacting inorganic solid comprising one or more metallic ions with an acid toproduce a liquid rich in the one or more metallic ions(b) contacting the liquid rich in the one or more metallic ions with a base comprising a carbonate salt and / or a bicarbonate salt to produce one or more metal carbonates, and / or insoluble salt or precipitate thereof, from the one or more metallic ions and a liquid deficient in the one or more metallic ions; and(c) contacting the liquid deficient in the one or more metallic ions with an electrolyzer to regenerate the acid and the base, wherein the carbonate salt and / or the bicarbonate salt are produced from admixing carbon dioxide and a metal hydroxide.Some embodiments provide a method of recycling metallic ion content from inorganic solid, the method comprising:(a) contacting inorganic solid comprising one or more metallic ions with an acid to produce a liquid rich in the one or more metallic ions; and(b) contacting the liquid rich in the one or more metallic ions with an electrolyzer to regenerate the acid and produce a precipitate comprising the one or more metallic ions.

[0011] Some embodiments provide a method of recycling metallic ion content from inorganic solid, the method comprising:(a) contacting inorganic solid comprising one or more metallic ions with an acid in an electrochemical cell to produce a liquid rich in the one or more metallic ions; and(b) contacting the liquid rich in the one or more metallic ions with a base in the electrochemical cell to form a precipitate comprising the one or more metallic ions and a liquid deficient in the one or more metallic ions; wherein the electrochemical cell comprises an anode reserv oir comprising an anode and the acid, and a cathode reservoir comprising a cathode and the base, wherein the anode reservoir and the cathode reservoir are separated by a separator.

[0012] Some embodiments provide a system for recycling metallic ion content from inorganic solid, comprising: an electrochemical cell configured to recycle metallic ion content, wherein the electrochemical cell comprises an anode reservoir comprising an anode and an acid, and a cathode reservoir comprising a cathode and a base, wherein the anode reservoir and the cathode reservoir are separated by a separator; a contactor configured to input inorganic solid comprising the one or more metallic ions into the anode reservoir, wherein the anode reservoir is configured to contact the inorganic solid with the acid to produce a liquid rich in the one or more metallic ions, and the cathodereservoir is configured to contact the liquid rich in the one or more metallic ions with the base to form a precipitate comprising the one or more metallic ions and a liquid deficient in the one or more metallic ions; and a first filtration system in contact with the cathode reservoir configured to filter out the precipitate from the cathode reservoir.

[0013] Other implementations of the above aspects include corresponding systems, apparatus, and computer programs, configured to perform the actions of the methods, encoded on computer storage devices. The details of one or more embodiments of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the subject matter will become apparent from the description, the drawings, and the claims.DETAILED DESCRIPTION

[0014] Methods of recycling inorganic solids from electronics, slag, and other waste streams typically involve using fossil fuels to melt out the undesired materials or other energy- intensive and low-yield methods, thus removing some metal content from the waste, while expelling enormous volumes of carbon dioxide into the atmosphere. The present disclosure provides regenerative electrochemical processes to remove metal ions from various forms of inorganic solid waste, thus reducing the overall environmental impact of the waste itself and mitigating the amount of carbon dioxide produced in the process.Definitions

[0015] To facilitate understanding of the disclosure set forth herein, a number of additional terms are defined below. Generally, the nomenclature and procedures described herein are those well-known and commonly employed in the art. Unless defined otherwise, all technical and scientific terms used herein generally have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Each of the patents, applications, published applications, and other publications that are mentioned throughout the specification and the attached appendices are incorporated herein by reference in their entireties.

[0016] The term “about” when referring to a number or a numerical range means that the number or numerical range referred to is an approximation, for example, within experimental variability and / or statistical experimental error, and thus the number or numerical range may vary up to ±10% of the stated number or numerical range.

[0017] The term “regeneration” as used herein refers to a step in a process for using the product of a particular step in the process as a reactant or starting material in another step in the process. For example, if compound A is formed from reacting compounds C and X, one of the products of the reaction A+B -> C+D, compound C, can be further reacted with X to provide A, the starting material for the A+B reaction.

[0018] The term “electrochemical cell” as used here refers to devices and / or device components that perform electrochemistry. Electrochemical cells have two or more electrodes (e.g., a cathode and an anode) and one or more electrolytes.

[0019] The term “separator” as defined herein, refers to the material between the cathode and anode reservoirs in an electrochemical cell. Representative separators include, but are not limited to cation exchange membranes and anion exchange membranes.

[0020] The term “sequential electrolysis” as used herein refers to a process wherein a substrate is oxidized or reduced sequentially.

[0021] The term “multi-ion sequential electrowinning” as used herein refers to the electrochemical process that separates different materials in space over may linked cells, or one cell in time via differences cell pH and / or cell voltage, analogous to a traditional distillation column that separates materials by boiling point. In a constant-current electrolysis (i.e., continuous multi-ion sequential el ectrowinning), voltage plateaus when one species is precipitating out and then rapidly increases until another species begins to precipitate.

[0022] The terms “liquid rich in” an ingredient(s) as provided throughout the disclosure is intended to mean that the liquid contains a concentration of at least 0.1 M of said ingredient(s). For example, the terms “liquid rich in one or more metallic ions” refers to a liquid having a one or more metallic ion concentration of at least 0.1 M (e.g., 0. 1 M to 5 M).

[0023] The terms “liquid deficient in” an ingredient(s) as provided throughout the disclosure is intended to mean that the liquid contains a concentration of less than 0. 1 M of said ingredient(s). For example, the terms “liquid deficient in one or more metallic ions” refers to a liquid having a one or more metallic ion concentration of less than 0.1 M (e.g., in a range of 0.0001-0.09 M).

[0024] The term “precipitate” as used herein refers to any solids that may form from a homogeneous solution. A precipitate may be comprised of heavy metal salts, and includes insoluble salts formed from any one or more metallic ions.

[0025] The term “ion” as used herein, refers to a species having a net electric charge due to loss or gain of one or more electrons; Non-limiting examples of ions include Na+. Fe3+, Fe2+, Mg2+, K+, Ca2+, and Pb2+. Reference herein to ions of specific elements refers to allpossible ions thereof; for example, ions of Cu include Cu and Cu2+.

[0026] Some embodiments provide a method of recycling metallic ion content from inorganic solid, the method comprising:(a) contacting an inorganic solid waste comprising one or more metallic ions with an acid to produce a liquid rich in the one or more metallic ions;(b) contacting the liquid rich in one or more metallic ions with a base to produce a precipitate comprising the one or more metallic ions and a liquid deficient in the one or more metallic ions;(c) contacting the liquid deficient in the one or more metallic ions with an electrolyzer to regenerate the acid and the base, and(d) repeating each of steps (a)-(b) at least once with the acid and the base from step (c).

[0027] In some embodiments, the inorganic solid comprises one or more of a group of steel, smelting slag, blast furnace slag, incinerator bottom ash, and electronics waste (e.g., batteries, solar cells, and other electronics). In some embodiments, the inorganic solid comprises smelting slag. In some embodiments, the inorganic solid comprises blast furnace slag. In some embodiments, the inorganic solid comprises incinerator bottom ash. In some embodiments, the inorganic solid comprises electronic waste. In some embodiments, the inorganic solid comprises batteries. In some embodiments, the inorganic solid is batteries, for example, shredded batteries and / or recycled batteries. In some embodiments, the inorganic solid comprises solar cells. In some embodiments, the inorganic solid is solar cells, for example, shredded solar cells and / or recycled solar cells. In some embodiments, the inorganic solid comprises electronics, such as household electronics. In some embodiments, the inorganic solid is electronics, for example, shredded electronics and / or recycled electronics. In some embodiments, the inorganic solid comprises an independently selected combination of two or more of steel, smelting slag, blast furnace slag, incinerator bottom ash, batteries, solar cells, steel, and electronics. In some embodiments, the inorganic solid is a combination of two or more of steel, smelting slag, blast furnace slag, incinerator bottom ash, batteries, solar cells, steel, and electronics.

[0028] Some embodiments provide a method of recycling metallic ion content from inorganic solid, the method comprising:(a) contacting the inorganic solid comprising one or more metallic ions with an acid to produce a liquid rich in the one or more metallic ions;(b) contacting the liquid rich in the one or more metallic ions with a base to produce a precipitate comprising the one or more metallic ions and a liquid deficient in the one or moremetallic ions;(c) contacting the liquid deficient in the one or more metallic ions with an electrolyzer to regenerate the acid and the base, and(d) repeating each of steps (a)-(b) at least once with the acid and the base from step (c).In some embodiments, the electrolyzer is a single-membrane electrolyzer, two- membrane salt splitting electrolyzer, a multi-membrane salt-splitting electrolyzer, a chloralkali electrolyzer, a bipolar membrane electrodialysis electrolyzer, or a combination of any of the foregoing.

[0029] Some embodiments provide a method of recycling metallic ion content from inorganic solid, the method comprising:(a) contacting the inorganic solid comprising one or more metallic ions with an acid to produce a liquid rich in the one or more metallic ions;(b) contacting the liquid rich in one or more metallic ions with a base and carbon dioxide to produce a precipitate comprising one or more metal carbonates from the one or more metallic ions and a liquid deficient in the one or more metallic ions; and(c) contacting the liquid deficient in one or more metallic ions with an electrolyzer to regenerate the acid and the base.

[0030] In some embodiments, step (b) comprises sequentially contacting the liquid rich in one or more metallic ions with two or more independently selected bases. In some embodiments, the bases are the same. In some embodiments, the bases are different. In some embodiments, the bases each comprise an independently selected metal hydroxide.

[0031] In some embodiments, the carbon dioxide is provided as a composition, wherein the composition comprises carbon dioxide and at least one additional gas, as described herein. For example, some embodiments described herein utilize carbon dioxide, for example, to produce a metal carbonate or bicarbonate from a metal hydroxide. In some embodiments, the carbon dioxide composition comprises a concentrated carbon dioxide source (e.g., flue gas from, for example, a power station). In some embodiments, the carbon dioxide composition comprises a dilute carbon dioxide source (e.g., atmospheric carbon dioxide). In other words, some embodiments described herein comprise carbon dioxide removal and sequestration.

[0032] In some embodiments, the composition comprises carbon dioxide in an amount of about 0.01 wt% to about 99.9 wt%, or about 0.01 wt% to about 1.5 wt%, or about 1 wt% to about 20 wt%, or about 5 wt% to about 20 wt%, or about 50 wt% to about 90 wt%. In some embodiments, the composition comprises carbon dioxide in an amount of about 0.01 wt% to about 99.9 wt%. In some embodiments, the composition comprises carbon dioxide in anamount of about 0.01 vrt.% to about 1.5 wt%. In some embodiments, the composition comprises carbon dioxide in an amount of about 1 wt% to about 10 wt%. In some embodiments, the composition comprises carbon dioxide in an amount of about 50 wt% to about 90 wt%.

[0033] In some embodiments, the carbonate salt and / or the bicarbonate salt is selected from sodium, potassium, lithium, and combinations of any of the foregoing. In some embodiments, the salt is sodium carbonate, potassium carbonate, lithium carbonate, or a combination of any of the foregoing. In some embodiments, the salt is sodium bicarbonate, potassium bicarbonate, lithium bicarbonate, or a combination of any of the foregoing.

[0034] Some embodiments provide a method of recycling metallic ion content from inorganic solid, the method comprising:(a) contacting the inorganic solid comprising one or more metallic ions with an acid to produce a liquid rich in one or more metallic ions; and(b) contacting the liquid rich in one or more metallic ions with an electrolyzer to regenerate the acid and produce a precipitate comprising the one or more metallic ions.

[0035] In some embodiments, the methods disclosed herein further comprise separating the precipitate and the acid of step (b).

[0036] In some embodiments, the methods disclosed herein further comprise repeating step (a) at least once with the acid from step (b).

[0037] In some embodiments, the methods disclosed herein further comprise separating the precipitate and the liquid deficient in the one or more metallic ions of step (b).

[0038] In some embodiments, the methods disclosed herein further comprise repeating each of steps (a)-(b) at least once using sequential electrolysis. In some embodiments, the sequential electrolysis occurs via continuous multi-ion sequential electrowinning. In some embodiments, the sequential electrolysis comprises continuous multi-ion sequential electrowinning. In some embodiments, the sequential electrolysis is continuous multi-ion sequential electrowinning.

[0039] Some embodiments provide a method of recycling metallic ion content from inorganic solid, the method comprising:(a) contacting inorganic solid comprising one or more metallic ions with an acid in an electrochemical cell to produce a liquid rich in one or more metallic ions; and(b) contacting the liquid rich in one or more metallic ions with a base in the electrochemical cell to form a precipitate comprising the one or more metallic ions and a liquid deficient in the one or more metallic ions; wherein the electrochemical cell comprises an anode reservoir comprising an anode andthe acid, and a cathode reservoir comprising a cathode and the base, wherein the anode reservoir and the cathode reservoir are separated by a separator.

[0040] In some embodiments, the separator is an anion exchange membrane or a cation exchange membrane. In some embodiments, the separator is an anion exchange membrane. In some embodiments, the separator is a cation exchange membrane.

[0041] In some embodiments, the methods disclosed herein further comprise repeating each of steps (a)-(b) at least once using sequential electrolysis. In some embodiments, the sequential electrolysis occurs via continuous multi-ion sequential electrowinning. In some embodiments, the sequential electrolysis comprises continuous multi-ion sequential electrowinning. In some embodiments, the sequential electrolysis is continuous multi-ion sequential electrowinning.

[0042] In some embodiments, the electrochemical cell comprises an anode reservoir comprising an anode and an acid, and a cathode reservoir comprising a cathode and a base, wherein the anode reservoir and the cathode reservoir are separated by a separator; a contactor configured to input inorganic solid comprising one or more metallic ions into the anode reservoir, wherein the anode reservoir is configured to contact the inorganic solid with the acid to produce a liquid rich in one or more metallic ions, and the cathode reservoir is configured to contact the liquid rich in one or more metallic ions with the base to form a precipitate comprising the one or more metallic ions and a liquid deficient in the one or more metallic ions; and a first filtration system in contact with the cathode reservoir configured to filter out the precipitate comprising the one or more metallic ions from the cathode reservoir.

[0043] In some embodiments, the first filtration system is additionally configured to filter the liquid, rich in one or more metallic ions, from input the liquid rich in one or more metallic ions into the cathode reservoir.

[0044] In some embodiments, the separator is an anion exchange membrane or a cation exchange membrane. In some embodiments, the separator is an anion exchange membrane. In some embodiments, the separator is a cation exchange membrane.

[0045] In some embodiments, contacting the inorganic solid comprising the one or more metallic ions with an acid produces a solid product and a liquid rich in the one or more metallic ions. In some embodiments, the solid product is steel product, smelting slag product, blast furnace slag product, incinerator bottom ash product, and electronics waste. The solid product, as disclosed herein, is defined as the inorganic solid after contacting the acid, the base, or both the acid and the base, wherein the acid, the base, or both the acid and the base reducethe metal ion content (e.g., reduce rust, metal hydroxides, metal oxides, or the like) of the inorganic solid to produce the solid product.

[0046] In some embodiments, the methods disclosed herein further comprising separating the solid product and the liquid rich in the one or more metallic ions prior to the next step of the method (if there is a next step).

[0047] In some embodiments, the contacting the liquid deficient in the one or more metallic ions with an electrolyzer in any of the methods disclosed herein produces a heavy metal precipitate comprising one or more metallic ions. In some embodiments, the heavy metal precipitate comprises Fe.

[0048] In some embodiments, the one or more metallic ions are selected from ions of lithium, sodium, potassium, beryllium, magnesium, calcium, strontium, barium, radium, aluminum, gallium, indium, tin, thallium, lead, bismuth, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, yttrium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, cadmium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, and mercury. In some embodiments, the one or more metallic ions are ionic pairs with one or more hydroxide anion to form metal hydroxides (e.g., Ca(OH)2). In some embodiments, the one or more metallic ions are ionic pairs with one or more oxide anion to form metal oxides (e.g., CaO, Fe20s, or the like).

[0049] In some embodiments, the one or more metallic ions are selected from ions of sodium, potassium, magnesium, calcium, tin, lead, iron, cobalt, nickel, copper, zinc, palladium, silver, cadmium, platinum, and gold.

[0050] In some embodiments, the one or more metallic ions will reduce at the cathode resulting in the one or more metals to deposit (plate) onto the cathode.

[0051] In some embodiments, the one or more metallic ions are selected from ions of sodium, potassium, magnesium, and calcium. In some embodiments, the one or more metallic ions are selected from ions of sodium, potassium, magnesium, calcium, and iron.

[0052] In some embodiments, performance of the methods and operation of the systems described herein is carbon neutral.

[0053] The methods disclosed herein can include (a) contacting the inorganic solid comprising one or more metal hydroxides and metal oxides with an acid to produce a liquid rich in the one or more metallic ions; (b) contacting the liquid rich in the one or more metallic ions with a base to produce a metal hydroxide and / or metal oxide precipitate (e.g., calcium hydroxide, ferrous oxide, or the like) and a liquid deficient in the one or more metallic ion; (c) contacting the liquid deficient in the one or more metallic ion with an electrolyzer to regeneratethe acid and the base. In some embodiments, the methods can include a step (d), wherein step (d) includes repeating each of steps (a)-(b) at least once with the acid and the base from step (c).

[0054] The methods disclosed herein can include (a) contacting the inorganic solid comprising one or more metal hydroxides and metal oxides with an acid to produce a liquid rich in the one or more metallic ions; (b) contacting the liquid rich in the one or more metallic ions with a base and carbon dioxide to produce a metal carbonate, and / or insoluble salt or precipitate thereof, and a liquid deficient in the one or more metallic ions; and (c) contacting the liquid deficient in the one or more metallic ions with an electrolyzer to regenerate the acid and the base.

[0055] The methods disclosed herein can include (a) contacting inorganic solid comprising one or more metal hydroxides and metal oxides with an acid to produce liquid rich in the one or more metallic ions; (b) contacting the liquid rich in the one or more metallic ions with a base comprising a carbonate salt and / or a bicarbonate salt to produce a metal carbonate, and / or insoluble salt or precipitate thereof, and a liquid deficient in the one or more metallic ions; and (c) contacting the liquid deficient in the one or more metallic ions with an electrolyzer to regenerate the acid and the base; wherein the carbonate salt and / or the bicarbonate salt are produced from admixing carbon dioxide and a metal hydroxide.

[0056] The methods disclosed herein can include (a) contacting inorganic solid comprising one or more metal hydroxides and metal oxides with an acid to produce a liquid rich in the one or more metallic ions; and (b) contacting the liquid rich in the one or more metallic ions with an electrolyzer to regenerate the acid and produce a metal ion precipitate.

[0057] The methods disclosed herein can include (a) contacting inorganic solid comprising one or more metal hydroxides and metal oxides with an acid in an electrochemical cell to produce a liquid rich in the one or more metallic ions; and (b) contacting the liquid rich in the one or more metallic ions with a base in the electrochemical cell to form a metal ion precipitate and a liquid deficient in the one or more metallic ions; wherein the electrochemical cell comprises an anode reservoir comprising an anode and the acid, and a cathode reservoir comprising a cathode and the base, wherein the anode reservoir and the cathode reservoir are separated by a separator.

[0058] Also provided herein are systems for recycling metallic ion content from inorganic solid. In some embodiments, the systems can include an electrochemical cell configured to recycle metallic ion content from inorganic solid, wherein the electrochemical cell comprises an anode reservoir comprising an anode and an acid, and a cathode reservoircomprising a cathode and a base, wherein the anode reservoir and the cathode reservoir are separated by a separator; a contactor configured to input inorganic solid comprising one or more metal hydroxides and / or metal oxides into the anode reservoir, wherein the anode reservoir is configured to contact the inorganic solid with the acid to produce liquid rich in the one or more metallic ions, and the cathode reservoir is configured to contact the liquid rich in the one or more metallic ions with the base to form a metal hydroxide and / or metal oxide precipitate and a liquid deficient in the one or more metallic ions; and a first filtration system in contact with the cathode reservoir configured to filter out the metal hydroxide and / or metal oxide precipitate from the cathode reservoir.

[0059] Exemplary methods of the disclosure include recycling metallic ion (e.g., Ca, Mg, and Fe) content from inorganic solid. The methods can include three steps. (1) acid treatment; (2) base treatment; and (3) electrolyzer for acid and base regeneration. Applicable acids, bases, and salts include, but is not limited to, to HC1, NaOH, NaCl and Ca(OH)2.

[0060] Acid Treatment: The inorganic solid is subject to reaction with an acid under controlled temperature and stirring. The solids, including metal hydroxides, such as Ca(OH)2, and metal oxides, such as CaO and Fe20s, on the surface of the inorganic solids are dissolved by the acid to form a liquid rich in one or more metallic ions. After acid treatment, if there are non-soluble metal material left over (e.g., solid product), the mixture of the solid product and the liquid rich in one or more metallic ions is filtered. The precipitates can then be washed and subject to sieving. A variety of acids, including but not limited to H2SO4. HC1. HNO3, HBr, HI, acetic acid, H3PO4, formic acid, maleic acid, can be used in the acid treatment step for the methods disclosed herein. The concentration of the acids can vary from 0.05 M to 30 M. Any ty pe of stirring / agitation methods may be applied to ensure sufficient reaction. In situ sensing, including but not limited to pH. conductivity’, atomic absorption spectroscopy. NMR spectroscopy, ICP-OES, can be implemented in this step and allow real-time monitoring of reaction progress and feedback control.

[0061] Base Treatment: The liquid rich in one or more metallic ions after filtration is mixed with a base (e.g., a base solution). The liquid rich in one or more metallic ions can include a calcium salt (e.g., one or more of CaCb, CaSO4, and Ca(NO3)2) and one or more of MgCh, FeCh, FeCk, MgSCh, Ca(NOs)2, and Mg(NOs)2, formed during the acid treatment. The liquid rich in one or more metallic ions reacts and turns to metal hydroxide and / or metal oxide precipitate (e.g., calcium hydroxide), including but not limited to Ca(OH)2, Mg(OH)2, Fe(OH)2. Fe(OH)3. A1(OH)3. which precipitates out from solution. The metal hydroxide and / or metal oxide precipitate are filtered out of the solution leaving a liquid deficient in one or moremetallic ions. It has been discovered that different metal hydroxides can precipitate out at different pH. Therefore, implementing in situ sensing can allow better monitoring of reaction progress and enable easier separation of different products. Just like the acid treatment step, a large variety of bases, at different concentrations, may be implemented in this step.

[0062] Electrolysis: The liquid deficient in one or more metallic ions from the filtration after the base treatment, has high salt concentration (such as one or more of LiCl, NaCl, KC1, Li2SO4, Na2SO4. K2SO4, LiNOs, NaNCh, and KNO3). The liquid deficient in one or more metallic ions is fed into an electrolyzer to generate the acid and base, used in steps 1 and 2, respectively. Several cell structures and electrolysis strategies can be implemented here. Some examples are explained below.

[0063] A two-membrane salt-splitting cell can be used in the methods disclosed herein, with water oxidation, i.e. H2O— > I / 2O2 + 2H++2e’, on the anode side and water reduction, i.e. 2H2O + 2e" — > H2 + 2OH", on the cathode side. The electrolyzer can include an anion exchange membrane (AEM) and a cation exchange membrane (CEM). In some embodiments, the AEM and CEM can be replaced with a bipolar membrane. The liquid deficient in one or more metallic ions can be fed into the central reservoir. When a large enough voltage is applied to the electrodes, a water splitting reaction takes place. At the anode, water is oxidized to oxygen, and the anions are pulled from the central reservoir, which results in an acid solution in the anode electrolyte. Meanwhile at the cathode, water is reduced to hydrogen, and cations are pulled from the central reservoir, creating a base electrolyte in the cathode reservoir. The thermodynamic voltage for the reaction is 1.23 V. In addition, a possible auxiliary device to this setup is a H2 + O2 fuel cell, which can cover part of the electricity cost.

[0064] A slightly modified version of the two-membrane salt splitting cell can be used in the methods depicted in FIG. 1 A. Instead of reduction of water on the cathode side, oxygen reduction, i.e. I / 2O2 + 2H2O + 2e" — > 2OH‘, is utilized, and the O2 gas is circulated in between anode and cathode side. There is a smaller voltage difference between anode and cathode (0 V to ~0.8 V depending on the pH gradient), which can lead to less energetic cost during electrolysis.

[0065] An additional electrolyzer that can be used in the methods disclosed herein. Instead of oxidation of water on the anode side, hydrogen oxidation, i.e. H2 — > 2H++ 2e‘, is utilized. Hydrogen is circulated internally. There is a smaller voltage difference between anode and cathode which can lead to less energetic cost during electrolysis.

[0066] Another possible electrolyzer that can be used in the methods disclosed herein is a classic chlor-alkali electrolyzer. A cation membrane separates the anode side from thecathode side. During electrolysis, chloride ions are oxidized to chlorine, i.e. 2C1’ Ch + 2e‘, at the anode, and water is reduced to hydrogen at the cathode. A fuel cell is required to convert hydrogen and chlorine into HC1 gas.

[0067] Further, a bipolar membrane electrodialysis cell (e.g., an electrodialysis cell as described in U.S. Pat. No. 9,586,181) can be used in the methods disclosed herein.

[0068] An additional method for recycling metallic ion content from inorganic solid is disclosed herein. The method is similar to the method previous method disclosed except for the addition of CCh-rich gas, such as flue gas or air, into the base treatment reservoir, thereby converting the metal hydroxides to metal carbonates (e.g., Ca(OH)2 to CaCO?). This is to combine carbon capture and sequestration with recycling metal content from inorganic solids. In addition, because of the low solubility of metal carbonates (e.g., CaCCh) in water, separation and purification of the metal carbonates from the liquid deficient in one or more metallic ions is much easier compared to metal hydroxides (e.g., Ca(OH)2). The same idea applies to other metal hydroxides, such as Mg(0H)2, Fe(OH)2, etc., and carbonates, e.g., but not limited to, MgCOs, FeCCh, Fe2(COs)3, etc. By sensing the CO2 concentration and flow rate at the inlet and exit, one can monitor CO2 capture in real time.

[0069] An additional method for recycling metallic ion content from inorganic solid disclosed herein. The base stream coming off from the electrolyzer is exposed to CO2 rich gas, such as flue gas or air, on a contactor, and is converted to aqueous carbonates, such as, but not limited to, Na2COs. NaHCO?, K.2CO3. and KHCO3. The aqueous base stream has higher basicity and concentration of active material compared to the semi-soluble base used in the methods disclosed herein. Therefore, the CO2 capture rate is expected to be faster and CO2 can be extracted from low concentration streams such as air. The aqueous carbonate stream reacts with the product of acid stream to form carbonate precipitates such as, but not limited to, CaCCh, MgCCh, Fe2(COs)3, or Ah(CO3)3. Different carbonate products will precipitate out at different pH, thus it is possible to obtain pure products through carefully controlling the titration process.

[0070] An additional method for reducing metal content in waste is disclosed herein. In this approach, the filtrate from the acid treatment is subject to direct electrolysis. Semisoluble hydroxides are formed in the cathode side of the electrolyzer and can be separated / purified for sale. This way, fewer steps are involved, so fewer reactors are needed. In addition, only one membrane is needed in the electrolyzer, which can decrease costs. Several electrolyzers can be used in the methods. The first design employs water oxidation at the anode and water reduction at the cathode. Only an AEM is used to separate two reservoirs. Chlorideis allowed to pass from the cathode side to the anode side during electrolysis. The filtrate from the acid treatment, containing CaCh or other soluble salts, is passed into the cathode side, and the resulting solution will contain high hydroxide content, both dissolved in water and in a slurry. To increase conductivity, a small amount, from 0.01 M to 1 M, of salt such as NaCl or KC1 can be added to the anode side. The second design is the same design as the first design except it uses oxygen reduction for the cathode. The third design that is the same design as the first design except it uses hydrogen oxidation for the anode.

[0071] An additional method for recycling metallic ion content from inorganic solid disclosed herein. In this approach, all the separated steps described in the original approach are combined together. The inorganic solid dissolution step (the acid treatment step) takes place in the anode reservoir of the electrolysis cell and the hydroxide precipitation step takes place in the cathode side of the cell. This system requires the least equipment, hence lower capital expenditures to realize. In addition, as soon as acid is generated at the anode, it is consumed by metal hydroxide (e.g., Ca(OH)2). The hydroxide generated at the cathode reacts with metal chlorides (e.g., CaCh) and form precipitates. Therefore, the pH gradient across the AEM will be small. This is beneficial because undesired ion leakage will be small and the concentration overpotential will also be small, leading to a lower energy cost. The hydroxides can include, but are not limited to, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, iron hydroxide (both iron(II) and iron(III)).

[0072] Two chamber single AEM membrane electrolyzers have a component cost and complexity advantage over multi membrane systems, but pose some unique challenges in scaling up. Namely, this configuration separates products in time rather than in spaces compared to the 2 membrane 3 chamber electrolyzers. To deal with this particularity, it is found that a batch wise system and a continuous system, can be useful. In the batch configuration, continuous processing would be achieved by a series of settling tank electrolyzer pairs connected by circulation pumps. In this configuration a given tank would be charged and the solution circulates through the electrizer to allow the desired hydroxides to precipitate out of solution and be collected in the connected setting tank. Continuous production can be achieved by staggered charging and processing of several of these pairs.

[0073] In the continuous system (e.g., continuous multi-ion sequential electrowinning via sequential electrolysis or continuous base treatment), several combined electrolyzer settling tank pairs would be combined in series. Different voltages are applied to each electrolyzer unit in order to precipitate out different hydroxide species at lower power consumption. The solution to be processed would flow slowly from one cell to the next producing a gradient orpH and precipitation products going down the line.

[0074] Particular embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims. For example, the actions recited in the claims can be performed in a different order and still achieve desirable results. As one example, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some cases, multitasking and parallel processing may be advantageous.

Claims

CLAIMS1. A method of recycling metallic ion content from inorganic solid, the method comprising:(a) contacting the inorganic solid comprising one or more metallic ions with an acid to produce a liquid rich in the one or more metallic ions;(b) contacting the liquid rich in the one or more metallic ions with a base to produce a precipitate comprising the one or more metallic ions and a liquid deficient in the one or more metallic ions;(c) contacting the liquid deficient in the one or more metallic ions with an electrolyzer to regenerate the acid and the base, and(d) repeating each of steps (a)-(b) at least once with the acid and the base from step (c).

2. The method of claim 1, wherein the contacting the liquid deficient in the one or more metallic ions with an electrolyzer produces a heavy metal precipitate comprising one or more metallic ions.

3. The method of claim 2, w herein the heavy metal precipitate comprises Fe.

4. The method of any one of claims 1-3. wherein the electrolyzer is a single-membrane electrolyzer, two-membrane salt splitting electrolyzer, a multi-membrane salt-splitting electrolyzer, a chlor-alkali electrolyzer, a bipolar membrane electrodialysis electrolyzer, or a combination of any of the foregoing.

5. A method of recycling metallic ion content from inorganic solid, the method comprising:(a) contacting the inorganic solid comprising one or more metallic ions with an acid to produce a liquid rich in the one or more metallic ions;(b) contacting the liquid rich in one or more metallic ions with a base and carbon dioxide to produce one or more metal carbonates, and / or insoluble salt or precipitate thereof, from the one or more metallic ions and a liquid deficient in the one or more metallic ions; and(c) contacting the liquid deficient in the one or more metallic ions with an electrolyzer to regenerate the acid and the base.

6. The method of any one of claims 1-5. wherein step (b) comprises sequentially contacting the liquid rich in the one or more metallic ions with two or more independently selected bases.

7. The method of any one of claims 1-6, further comprising separating the precipitate and the liquid deficient in the one or more metallic ions of step (b) prior to step (c).

8. A method of recycling metallic ion content from inorganic solid, the method comprising:(a) contacting the inorganic solid comprising one or more metallic ions with an acid to produce a liquid rich in the one or more metallic ions(b) contacting the liquid rich in the one or more metallic ions with a base comprising a carbonate salt and / or a bicarbonate salt to produce one or more metal carbonates, and / or insoluble salt or precipitate thereof, from the one or more metallic ions and a liquid deficient in the one or more metallic ions; and(c) contacting the liquid deficient in the one or more metallic ions with an electrolyzer to regenerate the acid and the base, wherein the carbonate salt and / or the bicarbonate salt are produced from admixing carbon dioxide and a metal hydroxide.

9. The method of any one of claims 5-8, wherein the carbon dioxide is provided as a composition, wherein the composition comprises carbon dioxide and at least one additional gas.

10. The method of claim 9, wherein the composition comprises carbon dioxide in an amount of about 0.01 wt% to about 99.9 wt%, or about 0.01 wt% to about 1.5 wt%, or about 1 wt% to about 10 wt%, or about 50 wt% to about 90 wt%.

11. The method of any one of claim 5-8. further comprising repeating each of steps (a)-(b) at least once with the acid and the base from step (c).

12. The method of claim any one of claims 8-11, wherein the carbonate salt and / or the bicarbonate salt is selected from sodium, potassium, lithium, and combinations of any of the foregoing.

13. A method of recycling metallic ion content from inorganic solid, the method comprising:(a) contacting the inorganic solid comprising one or more metallic ions with an acid to produce a liquid rich in the one or more metallic ions; and(b) contacting the liquid rich in the one or more metallic ions with an electrolyzer to regenerate the acid and produce a precipitate comprising the one or more metallic ions.

14. The method of claim 13, further comprising separating the precipitate and the acid of step (b).

15. The method of claim 13 or 14, further comprising repeating step (a) at least once with the acid from step (b).

16. The method of any one of claims 13-15, further comprising separating the precipitate and the liquid deficient in the one or more metallic ions of step (b).

17. The method of any one of claims 13-16, further comprising repeating each of steps (a)- (b) at least once using sequential electrolysis.

18. The method of claim 17, wherein the sequential electrolysis occurs via continuous multi-ion sequential electrowinning.

19. A method of recycling metallic ion content from inorganic solid, the method comprising:(a) contacting the inorganic solid comprising one or more metallic ions with an acid in an electrochemical cell to produce a liquid rich in the one or more metallic ions; and(b) contacting the liquid rich in the one or more metallic ions with a base in the electrochemical cell to form a precipitate comprising the one or more metallic ions and a liquid deficient in the one or more metallic ions; wherein the electrochemical cell comprises an anode resen' oir comprising an anode and the acid, and a cathode reservoir comprising a cathode and the base, wherein the anode reservoir and the cathode reservoir are separated by a separator.

20. The method of claim 19, wherein the separator is an anion exchange membrane.

21. The method of claim 19, wherein the separator is a cation exchange membrane.

22. The method of any one of claims 19-21, further comprising regenerating the acid and the base in the electrochemical cell.

23. The method of claim 13 or 19, further comprising repeating each of steps (a)-(b) at least once using sequential electrolysis.

24. The method of claim 23, wherein the sequential electrolysis occurs via continuous multi-ion sequential electrowinning.

25. The method of any one of claims 1-24, wherein contacting the inorganic solid comprising the one or more metallic ions with an acid further produces a solid product.

26. The method of claim 25, wherein the solid product is steel product, smelting slag product, blast furnace slag product, incinerator bottom ash product, and electronics waste product.

27. The method of claim 25 or 26, further comprising separating the solid product and the liquid rich in the one or more metallic ions prior to the next step.

28. A system for recycling metallic ion content from inorganic solid, comprising: an electrochemical cell configured to recycle metallic ion content from inorganic solid, wherein the electrochemical cell comprises an anode reservoir comprising an anode and an acid, and a cathode reservoir comprising a cathode and a base, wherein the anode reservoir and the cathode reservoir are separated by a separator; a contactor configured to input the inorganic solid comprising one or more metallic ions into the anode reservoir, wherein the anode reservoir is configured to contact the inorganic solid with the acid to produce a liquid rich in the one or more metallic ions, and the cathode reservoir is configured to contact the liquid rich in the one or more metallic ions with the base to form a precipitate comprising the one or more metallic ions and a liquid deficient in the oneor more metallic ions; and a first filtration system in contact with the cathode reservoir configured to filter out the precipitate comprising the one or more metallic ions from the cathode reservoir.

29. The system of claim 28, further comprising a tube connecting from the anode reservoir to the cathode reservoir configured to output hydrogen gas from the cathode reservoir and input hydrogen gas into the anode reservoir.

30. The system of claim 28 or 29, further comprising a conducting material connecting the anode to the cathode configure to output electrons from the anode and input the electrons to the cathode.

31. The system of any one of claims 28-30, further comprising a valve configured to input water into the anode reservoir.

32. The system of any one of claims 28-31, wherein the anode reservoir is configured to contact the inorganic solid with the acid to produce a solid product and a liquid rich in the one or more metallic ions.

33. The system of claim 32, further comprising a second filtration system in contact with the anode reservoir configured to filter out the solid product from the anode reservoir.

34. The system of any one of claims 28-31, wherein the second filtration system is additionally configured to filter the liquid rich in the one or more metallic ions from the solid product and input the liquid rich in the one or more metallic ions into the cathode reservoir.

35. The system of any one of claims 28-34, wherein the separator is an anion exchange membrane or a cation exchange membrane.

36. The method or system of any one of claims 1-35, wherein the inorganic solid comprises one or more of a group of steel, smelting slag, blast furnace slag, incinerator bottom ash, and electronics waste.

37. The method or system of any one of claims 1-36, wherein the inorganic solid is steel.

38. The method or system of any one of claims 1-36, wherein the inorganic solid is one or more of smelting slag, blast furnace slag, or incinerator bottom ash.

39. The method or system of any one of claims 1-36, wherein the inorganic solid is electronic waste.

40. The method or system of any one of claims 1 -36 or 39, wherein the inorganic solid is battery waste.

41. The method or system of any one of claims 1-40, wherein the one or more metallic ions are selected from ions of lithium, sodium, potassium, beryllium, magnesium, calcium, strontium, barium, radium, aluminum, gallium, indium, tin, thallium, lead, bismuth, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, yttrium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, cadmium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, and mercury.

42. The method or system of any one of claims 1-41, wherein the one or more metallic ions are selected from ions of sodium, potassium, magnesium, calcium, tin, lead, iron, cobalt, nickel, copper, zinc, palladium, silver, cadmium, platinum, and gold.

43. The method or system of any one of claims 1-42, wherein the one or more metallic ions are selected from ions of sodium, potassium, magnesium, and calcium.