WO2016126550A1

WO2016126550A1 - Expanded, mercury-sorbent materials

Info

Publication number: WO2016126550A1
Application number: PCT/US2016/015685
Authority: WO
Inventors: Thomas K. Gale
Original assignee: Novinda Corporation
Priority date: 2015-02-02
Filing date: 2016-01-29
Publication date: 2016-08-11

Abstract

Herein is disclosed products and processes related to mercury sorbent reactive agents supported on expanded inorganic supports. The products include compositions that have transition metal-sulfides (TM-sulfides) carried on internal surfaces of clay composites; TM- sulfides carried on internal surfaces of a layered clay material that include clay expansion additives; and TM-sulfides carried on exfoliated platelets. The methods of producing these compositions include admixing substrates (e.g., montmorillonite, sepiolite, halloystie, hectorite, mica, vermiculite, bentonite, nontronite, beidellite, volkonskoite, saponite, magadite, kenyaite, rectorite, attepulgite, kaolinite, calcined kaolinite, metakaolin, perlite, fly ash or mixtures thereof) copper (II) salts, sulfide salts, base, and clay expansion additive and optionally shearing the admixture; admixing interstratified clay composites, or precursors thereto, with a TM-salt and a sulfide salt; aerosolizing phyllosilicate materials to form exfoliated platelets and then coating the exfoliated platelets or other high surface area inorganic substrate with a TM-sulfide; and aerosolizing phyllosilicate materials with TM-salts and sulfide salts to form exfoliated platelets carrying a TM-sulfide.

Description

EXPANDED. MERCURY-SORBENT MATERIALS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This disclosure claims the benefit of priority to US Provisional Patent Application

No. 62/110,690, filed 02 February, 2015, the disclosure of which is incorporated herein in its entirety.

FIELD OF THE INVENTION

[0002] This disclosure is directed to mercury sorbent materials, specifically mercury reactive agents supported on expanded inorganic supports.

BACKGROUND

[0003] Mercury and its compounds are significant environmental pollutants and major threats to human life and natural ecosystems. Mercury is of significant environmental concern because of its toxicity, persistence in the environment, and bioaccumulation in the food chain. The toxicity of soluble Hg ions and elemental Hg even in very dilute concentrations has been widely reported in the literature. Mercury is released readily into the environment from natural and anthropogenic sources. Because of its physical and chemical properties, mercury can also be transported regionally through various environmental cycles. Atmospheric deposition of mercury is reported to be the primary cause of elevated mercury levels in fish which is a potential threat to pregnant women and young children.

[0004] In the United States, coal-fired power utility plants are the biggest source of mercury emissions into the air, emitting at least fifty metric tons of mercury into the atmosphere annually. Coal-fired combustion flue-gas streams are of particular concern because of their composition that includes trace amounts of acid gases, such as S0₂, NOx, and HCI, plus C0₂. Other sources of mercury emissions may include the chlor-alkali industry, ore smelting, gold refining, cement production, fossil fuel combustion, incineration of sewage sludge or municipal garbage, and the like.

[0005] The major chemical forms of mercury in combustion flue gases, including coal- fired flue gas, are elemental Hg° (i.e. zero valent) and oxidized mercury (e.g., Hg(l) and Hg(ll)). Mercury speciation (elemental or oxidized) and concentration is dependent on the source (e.g. the characteristics of the fuel being burned), process conditions, and the constituents in the ensuing gas streams (e.g., Cl₂, HCI, S0₂, N0_X, carbon). The oxidized form of mercury (typically HgCI₂) is the major species found in waste incinerators effluent. In coal-fired power plants, much of the elemental mercury released from the coal in the furnace remains due to the activation- energy barrier preventing the elemental mercury from oxidizing without sufficient catalytic assistance. Mercury in coal-fired power plants can be oxidized by the unburned carbon in the fly ash or SCR Catalysts, installed in many power plants to reduce NOx emissions. Depending on the plant, there may be enough contact with unburned carbon and/or SCR catalyst to convert all of the mercury to the oxidized form, or there may not be enough to oxidize any mercury, or there may be any other proportion of oxidized and elemental mercury at the stack. Unlike the oxidized forms, the metal in the zero valence state is difficult to remove due its high volatility, low reactivity, and low water solubility. Even the oxidized forms of mercury are difficult to capture completely in a stable non-volatile form.

SUMMARY

[0006] A first embodiment is a composition that includes a Transition metal sulfide (TM- sulfide) carried on the internal surfaces of a clay composite.

[0007] A second embodiment is a composition that includes a TM-sulfide carried on the internal surfaces of a layered clay composite and includes a clay expansion additive selected from the group consisting of an alcohol, a polydentate alcohol, an amine, a polydentate amine, a cationic amine, and a mixture thereof.

[0008] A third embodiment is a composition that includes a TM-sulfide carried on an exfoliated platelet; where the exfoliated platelet is selected from an exfoliated silicate platelet, an exfoliated aluminate platelet, and an exfoliated aluminosilicate platelet; preferably the platelet is an exfoliated clay platelet.

[0009] A fourth embodiment is a process of preparing a mercury sorbent material that includes admixing a substrate selected from the group consisting of montmorillonite, sepiolite, attepulgite, hectorite, mica, vermiculite, bentonite, nontronite, beidellite, volkonskoite, saponite, magadite, kenyaite, rectorite, halloysite, kaolinite, calcined kaolinite, metakaolin, perlite, fly ash or a mixture thereof, a TM-salt, a sulfide salt, a base, and a clay expansion additive; and then, optionally, shearing this admixture.

[0010] A fifth embodiment is a process for preparing TM-sulfide clay composite that includes admixing a material selected from an first interstratified clay composite; a first mineral selected from the groups consisting of smectite, vermiculite, illite, and chlorite; a second mineral selected from the groups consisting of smectite, vermiculite, illite, chlorite, pyrophyllite-talc, and kaolinite-serpentine; and a mixture thereof, with a TM-salt and a sulfide salt; and then, optionally, shearing the admixture.

[0011] A sixth embodiment is a process that includes aerosolizing a phyllosilicate material to form a plurality of exfoliated platelets and then coating the exfoliated platelets with a TM-sulfide.

[0012] A seventh embodiment is a process that includes aerosolizing a phyllosilicate material, TM-salt, and a sulfide salt and forming a plurality of exfoliated platelets carrying a TM- sulfide.

DETAILED DESCRIPTION

[0013] Improvements to mercury sorptive materials are described herein as

compositions and processes for manufacturing these compositions. Broadly, the herein disclosed procedures include an expansion of the reactive surface area of, for example, metal- sulfide carrying mercury sorbents.

[0014] Multiple embodiments of mercury sorbent materials with an expansion of the reactive surface are provided. A first embodiment is a composition that includes a transition metal sulfide ("TM-sulfide") carried on internal surfaces of a clay composite. A second embodiment is a composition that includes a TM-sulfide carried on internal surfaces of a layered clay material; and a clay expansion additive selected from the group consisting of an alcohol, a polydentate alcohol, an amine, a polydentate amine, a cationic amine, and a mixture thereof. A third embodiment is a composition that includes a TM-sulfide carried on an exfoliated platelet; where the exfoliated platelet is selected from an exfoliated silicate platelet, an exfoliated aluminate platelet, and an exfoliated aluminosilicate platelet; preferably, the platelet is an exfoliated clay platelet. In general, these embodiments include the expansion of interlayer distances beyond what is generally accessible from hydration of layered clay materials, and within certain embodiments the disruption of inter-platelet bonding, delamination of the platelets, and/or exfoliation of the clay materials.

[0015] A first embodiment includes a TM-sulfide carried on internal surfaces of a clay composite. Herein, a clay composite refers to a material with a silicate, aluminate, and/or aluminosilicate composition that includes a plurality of distinct crystalline platelets. In one example, the clay composite is an interstratified clay composite. For example, the clay composite can include at least one 2: 1 clay selected from the mineral groups consisting of smectite, vermiculite, illite, and chlorite. Preferably, the 2:1 clay is a mineral of the smectite or vermiculite group. Even more preferably, the 2: 1 clay is a mineral of the smectite group.

Examples of clays of the smectite group include, but are not limited to, montmorillonite, nontronite and saponite. Additionally, the clay composite can include a plurality of 2: 1 clays, for example a plurality of clays selected from the mineral groups consisting of smectite, vermiculite, illite, and chlorite. Preferably, the clay composite includes a plurality of 2:1 clays and at least one 2:1 clay is a mineral of the smectite group. More preferably, the clay composite is an interstratified composite of a mineral of the smectite group and a clay selected from the mineral groups consisting of smectite, vermiculite, illite, and chlorite. In one example, the clay composite can be an interstratification of two clays of the smectite group. In another example, the clay composite can be interstratified clays from different mineral groups. For example, the clay composite can be a material that is (A) an interstratification of a mineral of the smectite group and a mineral of the vermiculite group; (B) an interstratification of a mineral of the smectite group and a mineral of the chlorite group; (C) an interstratification of a mineral of the smectite group and a mineral of the pyrophyllite-talc group; or (D) an interstratification of a mineral of the smectite group and a mineral of the kaolinite-serpentine group.

[0016] In one instance, the clay composite can be identified as having a powder X-ray diffraction pattern that includes diffractions at angles not assigned to any of the plurality of included 2: 1 clays. Preferably, the powder X-ray diffraction pattern of the clay composite is free of diffractions at angles assigned to any of the included 2: 1 clays; as determined on air-dried samples. Notably, powder X-ray diffraction of clays is an analytical technique commonly used to determine inter-platelet spacing (from Basal reflections), where compositional analysis can be made by comparison of samples to reference files of clay diffraction angles. Where samples include a plurality of 2: 1 clays, the powder X-ray diffraction pattern, preferably, shows an amorphous material.

[0017] A composition that includes a TM-sulfide carried on internal surfaces of a clay composite can further include a clay expansion additive. As used herein, a clay expansion additive is a material that can intercalate between layers of a clay-like material and increases inter-layer spacing (e.g., interplatelet spacing, for example as evidenced by a decrease in the Basal diffraction value (° 2Θ)). The clay expansion additive can be selected from the group consisting of an alcohol, a polydentate alcohol, an amine, a polydentate amine, a cationic amine, and a mixture thereof. [0018] The second embodiment includes a TM-sulfide carried on internal surfaces of a layered clay material and further includes a clay expansion additive. Notably, the layered clay material of the second embodiment is not an interstratified clay. The layered clay material can be selected from montmorillonite, sepiolite, attepulgite, saponite, hectorite, kaolinite, halloysite, mica, vermiculite, bentonite, nontronite, beidellite, volkonskoite, magadite, and kenyaite.

Notably, as used herein, the term clay material typically refers to a mineral or synthetic mineral and is distinguished from the clay composite by the lack of the inclusion of intercalants, expansion additives, and/or interstratifying agents. The layered clay material can additionally be a mixture thereof without being an interstratified clay composite. Preferably, the layered clay material includes mica, vermiculite, bentonite, and/or montmorillonite. As noted above, the clay expansion additive can be selected from the group consisting of an alcohol, a polydentate alcohol, an amine, a polydentate amine, an ammonium salt, and a mixture thereof; and preferably intercalates between layers of the clay material and increases an inter-layer spacing.

[0019] In particular, a clay expansion additive, selected from the group consisting of an alcohol, a polydentate alcohol, an amine, a polydentate amine, a cationic amine, and a mixture thereof, can include: an alcohol which has the formula C_xH_2x+iOH where x has a value of 1 to 16; a polydentate alcohol which is an ethylenediol or a propylenediol; an amine which is a primary amine, a secondary amine, or a tertiary amine; a polydentate amine which is an ethylene diamine or a propylene diamine; a structural mixture that is an alkanolamine or an alkanol ammonium salt; a cationic amine which can include an ammonium salt (e.g., a salt including a primary ammonium cation, a secondary ammonium cation, a tertiary ammonium cation and a quaternary ammonium cation); or a compositional mixture of multiple clay expansion additives. An incomplete list of clay expansion additives include: methanol, ethanol, propanol, /^'-propanol, (n, i, f)-butanol, hexanol, cyclohexanol, octanol, decanol, dodecanol, tetradecanol, dodecanol, ethylenediol, propane-1 ,2-diol, (1 ,2 or 2,3)-butanediol, glycerol, a polydiol, ethylenediamine, ethylenediamine tetraacetate or acetic acid), propylenediamine, propylenediamine tetraacetate or acetic acid), ethanolamine, an ethanol ammonium salt, and/or an dialkylethanol ammonium salt. In another example, the clay expansion additive can be a clay deflocculant; for example, wherein the clay deflocculant is selected from the group consisting of a pyrophosphate salt, a polyacrylate salt, and a mixture thereof.

[0020] The compositions that include the interstratified clay composite or the layered clay material can further include a clay proppant. Herein, a clay proppant is a particulate material positioned between clay platelets that supports the separation of the platelets. For example, the clay proppant can be selected from the group consisting of silicate nanoparticles, aluminosilicate nanoparticles, aluminate nanoparticles, a chlorite, a rectorite, a kaolinite, a fly ash, or a mixture thereof. While proppants are common in the hydraulic fracturing industry, those proppants have a mean particle diameter that is too large to be applicable herein. The clay proppant necessitates a mean particle diameter that is less than a dimension of a clay platelet face, preferably less than the x and y dimensions of the clay platelet (where the z dimension is platelet thickness). Even more preferably, the clay proppants can have a mean particle diameter in the range of 20 nm to 1 ,000 nm, 20 nm to 750 nm, 25 nm to 500 nm, or 50 nm to 500 nm., or a mean particle diameter of about 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 or 100 nm.

[0021] In yet another embodiment of a mercury sorptive material, the composition can include a TM-sulfide carried on an exfoliated platelet. Herein, an exfoliated platelet is one layer of a clay that has been separated from other layers and is distributed in the composition in a "non-stacked" orientation. The exfoliated platelet can be selected from an exfoliated silicate platelet, an exfoliated aluminate platelet, and an exfoliated aluminosilicate platelet; preferably wherein the platelet consists of exfoliated clay platelet.

[0022] Herein, a TM-sulfide is carried on platelets and/or on internal surfaces of clay materials. The TM-sulfide can be selected from the group consisting of a manganese sulfide, an iron sulfide, a cobalt sulfide, a nickel sulfide, a copper sulfide, a zinc sulfide, and a mixture thereof. Notably, the TM-sulfide can be or include a tin sulfide; whereas tin is not a transition metal the use of "TM-sulfide" to designate the material carried on the platelet (or on surfaces of a clay) is herein recognized to include transition metals and/or tin. Preferably, the TM-sulfide is an amorphous and/or inhomogeneous metal sulfide that has higher reactivity for mercury (Hg°, Hg ⁺, and or Hg²⁺) than a crystalline example of the same metal sulfide. More preferably, the TM-sulfide can be selected from the group consisting of an iron sulfide, a nickel sulfide, a copper sulfide, a zinc sulfide, and a mixture thereof. Still more preferably, the TM-sulfide can be selected from the group consisting of an iron sulfide, a copper sulfide, and a mixture thereof. Discrete examples include a copper sulfide with a S/Cu ratio greater than 1.0, 1.1 , 1.5, 2, 3, or 5; an iron sulfide with a S/Fe ratio greater than 1.5, 2, 2.5, or 3; a copper iron sulfide with a Cu/Fe ratio of about 10/1 , 5/1 , 2/1 , 1/1 , 1/2, 1/5, or 1/10 and a S/metal (Cu+Fe) ratio greater than 1.2, 1.5, 2, 3, or 5.

[0023] Additional embodiments include processes for manufacturing the above described mercury sorbent materials. In one embodiment, the process can include admixing a substrate (e.g., selected from the group consisting of montmorillonite, sepiolite, attepulgite, saponite, hectorite, halloysite, mica, vermiculite, bentonite, nontronite, beidellite, volkonskoite, magadite, kenyaite, rectorite, kaolinite, calcined kaolinite, metakaolin, perlite, fly ash or a mixture thereof), a copper (II) salt, a sulfide salt, a base, and a clay expansion additive; and then shearing the admixture. In another embodiment, the process can include admixing an interstratified clay composite or a mixture of at least two of a first mineral; a second mineral, and an interstratified clay composite, with a TM-salt and a sulfide salt; and then shearing the admixture. In still another embodiment, the process can also include aerosolizing a phyllosilicate material to form a plurality of exfoliated platelets; and then coating the exfoliated platelets with a TM-sulfide. Still further, the process can include aerosolizing a phyllosilicate material, TM-salt, and a sulfide salt; and forming a plurality of exfoliated platelets carrying a TM-sulfide.

[0024] A first embodiment can include a process of preparing a mercury sorbent material by admixing a substrate selected from the group consisting of montmorillonite, sepiolite, hectorite, mica, vermiculite, bentonite, nontronite, beidellite, volkonskoite, saponite, magadite, kenyaite, rectorite, kaolinite, calcined kaolinite, metakaolin, perlite, fly ash or a mixture thereof, a copper (II) salt, a sulfide salt, a base, and a clay expansion additive; and then shearing the admixture. Preferably, the substrate is selected from the group consisting of montmorillonite, calcined montmorillonite, sepiolite, mica, vermiculite, bentonite, kaolinite, calcined kaolinite, metakaolin, fly ash or a mixture thereof. More preferably, the substrate is selected from the group consisting of montmorillonite, calcined kaolinite, metakaolin, fly ash or a mixture thereof. Still more preferably, the substrate is montmorillonite or bentonite. The copper (II) salt can be selected from a copper halide (e.g., CuCI₂, CuBr₂), a copper nitrate, a copper sulfate, a copper sulfite, a copper phosphate, a copper chlorate, a copper perchlorate, a copper carbonate, or a mixture thereof. In one preferable example, the copper (II) salt is a copper sulfate. The sulfide salt can be an alkali metal hydrosulfide (e.g., NaSH), an alkali metal sulfide (e.g., Na₂S), an alkali metal polysulfide (e.g., Na₂S_x where x can be 2, 3, 4, 5, 6, 7, 8, 9, or 10), an alkali metal hydropolysulfide (e.g., NaS₂H; notably higher hydropolysulfides are often unstable to disproportionation and are observed as mixtures of the alkali metal polysulfide and hydrogen sulfide), and mixtures thereof. The base can be selected from alkali metal carbonates (e.g., Na₂C0₃), alkali metal bicarbonates (e.g., NaHC0₃), alkali earth carbonates (e.g., MgC0₃, CaC0₃), alkali metal hydroxides (e.g., NaOH or KOH), alkali earth hydroxides (Ca[OH]₂), and mixtures thereof (e.g., Trona). The clay expansion additive, preferably intercalates between layers of the substrate, increases an inter-layer spacing, and is selected from the group consisting of an alcohol, a polydentate alcohol, an amine, a polydentate amine, a cationic amine, and a mixture thereof. The clay expansion additive can include: an alcohol which has the formula C_xH_2x+iOH where x has a value of 1 to 16; a polydentate alcohol which is an

ethylenediol or a propylenediol; an amine which is a primary amine, a secondary amine, or a tertiary amine; a polydentate amine which is an ethylene diamine or a propylene diamine; a structural mixture that is an alkanolamine or an alkanol ammonium salt; a cationic amine which can include an ammonium salt (e.g. , a salt including a primary ammonium cation, a secondary ammonium cation, a tertiary ammonium cation and a quaternary ammonium cation); or a compositional mixture of multiple clay expansion additives. An incomplete list of clay expansion additives include: methanol, ethanol, propanol, /^'-propanol, (n, i, f)-butanol, hexanol,

cyclohexanol, octanol, decanol, dodecanol, tetradecanol, dodecanol, ethylenediol, propane-1 ,2- diol, (1 ,2 or 2,3)-butanediol, glycerol, a polydiol, ethylenediamine, ethylenediamine tetraacetate or acetic acid), propylenediamine, propylenediamine tetraacetate or acetic acid), ethanolamine, an ethanol ammonium salt, and/or an dialkylethanol ammonium salt. In another example, the clay expansion additive can be a clay deflocculant; for example, wherein the clay deflocculant is selected from the group consisting of a pyrophosphate salt, a polyacrylate salt, and a mixture thereof.

[0025] The process of preparing a mercury sorbent material can further include spray drying and/or pulse drying the sheared admixture. That is, after shearing, the admixture can be processed using a spray dryer, pulse dryer, or a pulse combustion spray dryer.

[0026] In one example, shearing the admixture includes extruding, pin mixing, or rotor- stator mixing the admixture. Shearing may employ extruders, injection molding machines, BANBURY type mixers, BRABEN DER type mixers, pin-mixers, and the like. Shearing also can be achieved by introducing an admixture at one end of an extruder (single or double screw) and receiving the sheared material at the other end of the extruder. The temperature of the materials entering the extruder, the temperature of the extruder, the concentration of materials added to the extruder, the amount of water added to the extruder, the length of the extruder, residence time of the materials in the extruder, and the design of the extruder (single screw, twin screw, number of flights per unit length, channel depth, flight clearance, mixing zone, etc.) are several variables which control the amount of shear applied to the materials.

[0027] Another feature of the process is the order of addition of the substrate, TM-salt

(e.g. , copper salt), sulfide salt, base, and clay expansion additive prior to shearing. In one example, the process can include admixing the substrate and the clay expansion additive; then admixing the substrate-clay expansion additive admixture with a copper (I I) salt and a sulfide salt, before shearing the admixture. In another example, the process can include admixing the substrate, the clay expansion additive, and the base; then admixing the substrate-clay expansion additive-base admixture with a copper salt and a sulfide salt, before shearing the admixture. In still another example, the process can include admixing the substrate, the clay expansion additive, and the copper salt; then admixing the substrate-clay expansion additive- copper salt admixture with the sulfide salt, before shearing the admixture. In yet another example, the process can include admixing the substrate and the copper salt; then admixing the substrate-copper salt admixture with the clay expansion additive and the sulfide salt, before shearing the admixture.

[0028] Yet another embodiment is a process for preparing a TM-sulfide clay composite.

This process can include admixing an interstratified clay or components for a interstratified clay with a TM-salt and a sulfide salt, then shearing the admixture. For example, the process can include a material selected from a first interstratified clay composite; a first mineral selected from the groups consisting of smectite, vermiculite, illite, and chlorite; a second mineral selected from the groups consisting of smectite, vermiculite, illite, chlorite, pyrophyllite-talc, and kaolinite- serpentine; and a mixture thereof. In one instance, the process includes the interstratified clay. In another instance, the process includes a mixture of the interstratified clay and the first mineral, the interstratified clay and the second mineral, the interstratified clay, the first mineral and the second mineral, or the first mineral and the second mineral. In an instance where the process does not include the interstratified clay, the process includes a mixture of the first mineral and the second mineral. For example, the process can include providing the first interstratified clay composite; that is, providing a first mineral selected from the groups consisting of smectite, vermiculite, illite, and chlorite, and a second mineral selected from the groups consisting of smectite, vermiculite, illite, chlorite, pyrophyllite-talc, and kaolinite- serpentine; and then interstratifying the first mineral and the second mineral to form the first interstratified clay composite. Preferably, the shearing forms a second interstratified clay composite that includes the TM-sulfide. For example, from the first mineral and the second mineral.

[0029] This process can further include admixing a base and/or a clay expansion additive with the TM-salt prior to shearing the admixture. The base can be selected from alkali metal carbonates (e.g., Na₂C0₃), alkali metal bicarbonates (e.g., NaHC0₃), alkali earth carbonates (e.g., MgC0₃), alkali metal hydroxides (e.g., NaOH or KOH), alkali earth hydroxides (Ca[OH]₂), and mixtures thereof (e.g., Trona). Preferably, the base is a sodium carbonate and/or a lime. The clay expansion can be selected from the group consisting of an alcohol, a polydentate alcohol, an amine, a polydentate amine, a cationic amine, and a mixture thereof. That is, the clay expansion additive can include: an alcohol which has the formula C_xH_2x+iOH where x has a value of 1 to 16; a polydentate alcohol which is an ethylenediol or a

propylenediol; an amine which is a primary amine, a secondary amine, or a tertiary amine; a polydentate amine which is an ethylene diamine or a propylene diamine; a structural mixture that is an alkanolamine or an alkanol ammonium salt; a cationic amine which can include an ammonium salt (e.g., a salt including a primary ammonium cation, a secondary ammonium cation, a tertiary ammonium cation and a quaternary ammonium cation); or a compositional mixture of multiple clay expansion additives. An incomplete list of clay expansion additives include: methanol, ethanol, propanol, /^'-propanol, (n, i, f)-butanol, hexanol, cyclohexanol, octanol, decanol, dodecanol, tetradecanol, dodecanol, ethylenediol, propane-1 ,2-diol, (1 ,2 or 2,3)-butanediol, glycerol, a polydiol, ethylenediamine, ethylenediamine tetraacetate or acetic acid), propylenediamine, propylenediamine tetraacetate or acetic acid), ethanolamine, an ethanol ammonium salt, and/or an dialkylethanol ammonium salt.

[0030] In one example, the admixing of the interstratified clay composite with the TM- salt and the sulfide salt includes admixing the interstratified clay composite with the TM-salt and then admixing the TM-salt clay composite with the sulfide salt. In another example, the interstratified clay composite can be admixed with the sulfide salt and then with the TM-salt. In another example, the three components are contemporaneously admixed prior to shearing.

[0031] Preferably, the TM-sulfide is selected from the group consisting of a manganese sulfide, an iron sulfide, a cobalt sulfide, a nickel sulfide, a copper sulfide, a zinc sulfide, a tin sulfide, and a mixture thereof; more preferably selected from the group consisting of iron sulfide, nickel sulfide, copper sulfide, zinc sulfide, and a mixture thereof; or even more preferably selected from the group consisting of iron sulfide, copper sulfide, and a mixture thereof.

Accordingly, the TM-salt can be selected from manganese, iron, cobalt, nickel, copper, and/or zinc salts, which are, for example, halides (chloride/bromide), sulfates, sulfites, chlorates, perchlorates, carbonates, nitrates, nitrites, phosphates, or mixtures thereof. Generally, the anion is selected for the thermodynamically favorable formation of a sodium or potassium salt (from the sulfide salt). In other instances, the anion is selected from a group that produces a TM- sulfide with a non-idealized composition (e.g. , X(TM-sulfide)A; where X can be a cation (e.g., Na, K) and A can be an anion other than sulfide/polysulfide (e.g. , S0₃; N0₂; Br). [0032] In another embodiment, a process of manufacturing the herein described mercury sorbent materials utilizes exfoliated platelets of phyllosilicate materials. In one instance, the process can include aerosolizing a phyllosilicate material to form a plurality of exfoliated platelets and then coating the exfoliated platelets with a TM-sulfide. In another instance, the process can include aerosolizing a mixture of the phyllosilicate material, TM-salt, and sulfide salt; and forming a plurality of exfoliated platelets carrying a TM-sulfide. In yet another instance, the process can include aerosolizing the phyllosilicate material and the TM-salt, and then adding a sulfide salt. Herein, the process of aerosolizing can include evaporative aerosolization wherein, preferably, the average particle-size distribution decreases as compared to the phyllosilicate material. In one instance, the process includes evaporative aerosolization of an admixture of a phyllosilicate material and a TM-salt into a volume that includes a positive hydrogen sulfide partial pressure.

[0033] In another example, the phyllosilicate material includes a clay and a clay expansion additive. The clay expansion additive is, preferably, selected from the group consisting of an alcohol, a polydentate alcohol, an amine, a polydentate amine, a cationic amine, and a mixture thereof.

[0034] Preferably, the TM-sulfide is selected from the group consisting of a manganese sulfide, an iron sulfide, a cobalt sulfide, a nickel sulfide, a copper sulfide, a zinc sulfide, a tin sulfide, and a mixture thereof; more preferably selected from the group consisting of iron sulfide, nickel sulfide, copper sulfide, zinc sulfide, and a mixture thereof; or even more preferably selected from the group consisting of iron sulfide, copper sulfide, and a mixture thereof.

Accordingly, the TM-salt can be selected from manganese, iron, cobalt, nickel, copper, tin, and/or zinc salts - for example, the respective halides (chloride/bromide), sulfates, sulfites, chlorates, perchlorates, carbonates, nitrates, nitrites, phosphates, or mixtures thereof.

Generally, the anion is selected for the thermodynamically favorable formation of a sodium or potassium salt (from the sulfide salt).

[0035] In one particularly preferable instance, the coating of the exfoliated platelets with a TM-sulfide includes coating the exfoliated platelets with a copper salt and then coating the exfoliated platelets with a sulfide salt, preferably forming a copper sulfide on the surface of the exfoliated platelets. In another preferable instance, the coating of the exfoliated platelets with a TM-sulfide includes coating the exfoliated platelets with a copper sulfide admixture.

Claims

WHAT IS CLAIMED:

1. A composition comprising:

a TM-sulfide carried on internal surfaces of an interstratified clay composite; wherein the TM-sulfide is selected from the group consisting of a manganese sulfide, an iron sulfide, a cobalt sulfide, a nickel sulfide, a copper sulfide, a zinc sulfide, a tin sulfide, and a mixture thereof.

2. The composition of claim 1 , wherein the clay composite comprises at least one 2: 1 clay selected from minerals the groups consisting of smectite, vermiculite, illite, and chlorite.

3. The composition of claim 2, wherein the clay composite comprises a plurality of 2: 1 clays; preferably, wherein at least one 2: 1 clay is a mineral of the smectite group.

4. The composition of claim 3, wherein the clay composite has a powder X-ray diffraction pattern that includes diffractions at angles not assigned to any of the plurality of included 2: 1 clays; preferably, wherein the powder X-ray diffraction pattern is free of diffractions at angles assigned to any of the included 2:1 clays; as determined on air-dried samples.

5. The composition of claim 1 , wherein the clay composite is selected from the group consisting of an interstratification of a mineral of the smectite group and a mineral of the vermiculite group; an interstratification of a mineral of the smectite group and a mineral of the chlorite group; an interstratification of a mineral of the smectite group and a mineral of the pyrophyllite-talc group; and an interstratification of a mineral of the smectite group and a mineral of the kaolinite-serpentine group.

6. The composition of claim 1 further comprising a clay expansion additive selected from the group consisting of an alcohol, a polydentate alcohol, an amine, a polydentate amine, a cationic amine, and a mixture thereof.

7. The composition of claim 6, wherein the clay expansion additive is intercalated between layers of the clay composite and increases an inter-layer spacing.

8. The composition of claim 7,

wherein the alcohol has the formula C_xH_2x+iOH where x has a value of 1 to 16; wherein the polydentate alcohol is an ethylenediol or a propylenediol;

wherein the amine is a primary amine, a secondary amine, or a tertiary amine; wherein the polydentate amine is an ethylene diamine or a propylene diamine; wherein the mixture is an alkanolamine; and wherein the cationic amine includes an ammonium cation, a primary ammonium cation, a secondary ammonium cation, a tertiary ammonium cation and a quaternary ammonium cation.

9. The composition of claim 1 , wherein the clay composite includes a clay material selected from the group consisting of montmorillonite, attapulgite, sepiolite, hectorite, halloysite, kaolinite, mica, vermiculite, bentonite, nontronite, beidellite, volkonskoite, saponite, magadite, kenyaite, or a mixture thereof.

10. The composition of claim 9 further comprising a clay proppant; wherein the clay proppant is selected from the group consisting of silicate nanoparticles, aluminosilicate nanoparticles, aluminate nanoparticles, a chlorite, a rectorite, a kaolinite, a fly ash, or a mixture thereof.

11. A composition comprising:

a TM-sulfide carried on an exfoliated platelet;

wherein the exfoliated platelet is selected from an exfoliated silicate platelet, an exfoliated aluminate platelet, and an exfoliated aluminosilicate platelet; preferably wherein the exfoliated platelet consists of exfoliated clay platelet; wherein the TM-sulfide is selected from the group consisting of a manganese sulfide, an iron sulfide, a cobalt sulfide, a nickel sulfide, a copper sulfide, a zinc sulfide, a tin sulfide, and a mixture thereof.

12. A process comprising:

aerosolizing a phyllosilicate material to form a plurality of exfoliated platelets; and then

coating the exfoliated platelets with a TM-sulfide; thereby

forming a plurality of exfoliated platelets carrying a TM-sulfide.

13. The process of claim 12 further comprising forming the TM-sulfide from an admixture of an aerosolized TM-salt and an aerosolized sulfide salt.

14. The process of claim 13, wherein coating the exfoliated platelets with a TM- sulfide includes coating the exfoliated platelets with a copper salt and then coating the exfoliated platelets with a sulfide salt.

15. The process of claim 12, wherein coating the exfoliated platelets with a TM- sulfide includes coating the exfoliated platelets with a copper sulfide admixture.

16. The process of any one of claims 12, wherein the phyllosilicate material includes a clay and a clay expansion additive selected from the group consisting of an alcohol, a polydentate alcohol, an amine, a polydentate amine, a cationic amine, and a mixture thereof.

17. The process of any one of claims 12, wherein the TM-sulfide is selected from the group consisting of a manganese sulfide, an iron sulfide, a cobalt sulfide, a nickel sulfide, a copper sulfide, a zinc sulfide, a tin sulfide, and a mixture thereof; preferably selected from the group consisting of iron sulfide, nickel sulfide, copper sulfide, zinc sulfide, and a mixture thereof; more preferably selected from the group consisting of iron sulfide, copper sulfide, and a mixture thereof.