Abstract: The present disclosure is directed, in certain embodiments, to processes for recovering metals from polymetallic nodules. The processes may include one or both of (i) a weak acid wash of the polymetallic nodule material and (ii) nano-filtration and/or limestone neutralization of recycled manganese-rich stream to remove magnesium from process streams to improve the recovery of target metals, including manganese. The processes may include cobalt and/or nickel solvent extraction to improve metal(s) recovery.

Abstract: A process for selectively extracting cobalt from a composition comprising cobalt and one or more other metal elements, wherein the process comprises the following steps: a) a step of forming a precipitate consisting of a coordination complex comprising cobalt, by bringing the solution into contact with at least one aromatic compound comprising at least two nitrogen atoms in its ring; b) a step of recovering the precipitate.

Abstract: The disclosure discloses a method for preparing a high-voltage cathode material by body modification and regeneration of a waste lithium cobaltate material.

Abstract: There is provided a means capable of recovering a valuable material such as cobalt and nickel, with a low grade of a metal derived from a negative electrode current collector, a low grade of fluorine, and a low grade of a material derived from a negative electrode active material. A method for recovering a valuable material from a lithium ion secondary battery, is characterized in that it includes: a heat treatment step of performing heat treatment on a lithium ion secondary battery; a crushing step of crushing a heat-treated object obtained through the heat treatment step; a classification step of classifying a crushed object obtained through the crushing step into a coarse particle product and a fine particle product; and a wet magnetic separation step of performing wet magnetic separation on the fine particle product obtained through the classification step.

Abstract: A method, and systems in which such method may be practiced, allow for the separation of elemental metals from metal alloy. A metal alloy is atomized to form metal alloy particulates. The metal alloy particulates are exposed to an oxidizing agent, such as chlorine gas in the presence of a salt, such as NaCl, an acid, such as HCl, and water. The resulting solution may be filtered to remove particulates, reduced, filtered, reduced, filtered, and so on. In aspects, the method is used to refine gold alloy by oxidation of elemental sponge gold to gold chloride followed by reduction to pure elemental gold.

Abstract: A polyvinyl alcohol is produced in a method comprising: a polymerization step comprising polymerizing vinyl ester monomers by controlled radical polymerization in the presence of a radical initiator and an organic cobalt complex to obtain a polymer solution containing a polyvinyl ester; an extraction step comprising extracting a cobalt complex from the polymer solution by contacting an aqueous solution containing a water-soluble ligand with the polymer solution; and a saponification step comprising saponifying the polyvinyl ester after the extraction step to obtain a polyvinyl alcohol. A method for producing a polyvinyl alcohol is thus provided that has a narrow molecular weight distribution and a high number-average molecular weight with good hue and further good solubility in water.

Abstract: The invention relates to a method and apparatus for recovering metals from metalliferous starting materials comprising steps of i) leaching the metalliferous starting material in chloride-based leaching liquor, ii) withdrawing from the leaching step i) aqueous chloride solution with dissolved metals, iii) recovering metal value from the aqueous chloride solution in a metal recovery process step, iv) neutralizing hydrogen chloride content of the aqueous chloride solution in the metal recovery process step with adding hydrolyzed ammonia to the process solution so as to form ammonium chloride, v) withdrawing ammonium chloride containing process solution to an ammonium regeneration step where calcium-containing reagent is added to generate calcium chloride and ammonia gas and recycling ammonia back to the metal recovery process step iii), vi) regenerating the CaCl2-solution with H2SO4 so as to provide a aqueous HCl solution for recycling to the leaching step i).

Abstract: The present disclosure relates to a process and system for recovery of one or more metal values using solution extraction techniques and to a system for metal value recovery. In an exemplary embodiment, the solution extraction system comprises a first solution extraction circuit and a second solution extraction circuit. A first metal-bearing solution is provided to the first and second circuit, and a second metal-bearing solution is provided to the first circuit. The first circuit produces a first rich electrolyte solution, which can be forwarded to primary metal value recovery, and a low-grade raffinate, which is forwarded to secondary metal value recovery. The second circuit produces a second rich electrolyte solution, which is also forwarded to primary metal value recovery. The first and second solution extraction circuits have independent organic phases and each circuit can operate independently of the other circuit.

Abstract: A method for preparing a catalyst having catalytically active materials selectively impregnated or supported only in the surface region of the catalyst particle using the mutual repulsive force of a hydrophobic solution and a hydrophilic solution and the solubility difference to a metal salt precursor between the hydrophobic and hydrophilic solutions. The hydrophobic solvent is a C2-C6 alcohol. The hydrophobic solvent is introduced into the catalyst support and then removed of a part of the pores connected to the outer part of the catalyst particle by drying under appropriate conditions. Then, a hydrophilic solution containing a metal salt is introduced to occupy the void spaces removed of the hydrophobic solvent, and the catalyst particle is dried at a low rate to selectively support or impregnate the catalytically active material or the precursor of the catalytically active material only in the outer part of the catalyst particle.

Abstract: A method of recovering metals from electronic waste comprises providing a powder comprising electronic waste in at least a first reactor and a second reactor and providing an electrolyte comprising at least ferric ions in an electrochemical cell in fluid communication with the first reactor and the second reactor. The method further includes contacting the powders within the first reactor and the second reactor with the electrolyte to dissolve at least one base metal from each reactor into the electrolyte and reduce at least some of the ferric ions to ferrous ions. The ferrous ions are oxidized at an anode of the electrochemical cell to regenerate the ferric ions. The powder within the second reactor comprises a higher weight percent of the at least one base metal than the powder in the first reactor. Additional methods of recovering metals from electronic waste are also described, as well as an apparatus of recovering metals from electronic waste.

Abstract: Method of converting calcium bentonite to sodium bentonite that is suitable for use as drilling mud or a cement additive. After the addition of a calcium bentonite sample to a prepared soda ash solution at predetermined soda ash/bentonite weight ratios, the bentonite suspension is continuously heated and stirred for up to 24 h. The heating and stirring are crucial towards enhancing the sodium activation of the bentonite, as well as other rheological properties of the bentonite.

Abstract: A micronutrient supplement which is made by reacting together copper metal and either hydrochloric acid and/or cupric chloride under oxidizing conditions.

Abstract: A micronutrient supplement which is made by reacting together copper metal and either hydrochloric acid and/or cupric chloride under oxidizing conditions.

Abstract: The application of aqueous solution of magnesium bicarbonate and/or calcium bicarbonate in the process of extraction separation and purification of metals is disclosed, wherein the aqueous solution of magnesium bicarbonate and/or calcium bicarbonate is used as an acidity balancing agent, in order to adjust the balancing pH value of the extraction separation process which uses an acidic organic extractant, improve the extraction capacity of organic phase, and increase the concentration of metal ions in the loaded organic phase.

Abstract: The present application relates to novel gel-type or macroporous picolylamine resins which are based on at least one monovinylaromatic compound and at least one polyvinylaromatic compound and/or a (meth)acrylic compound and contain tertiary nitrogen atoms in structures of the general formula (I) as functional group, where R1 is an optionally substituted radical from the group consisting of picolyl, methylquinoline and methylpiperidine, R2 is —CH2—S—CH2COOR3 or —CH2—S—C1-C4-alkyl or —CH2—S—CH2CH(NH2)COOR3 or —CH2—S—CH2—CH(OH)—CH2(OH) or or derivatives thereof or —C?S(NH2), R3 is a radical from the group consisting of H, Na and K, m is an integer from 1 to 4, n and p are each, independently of one another, a number in the range from 0.1 to 1.9 and the sum of n and p is 2 and M is the polymer matrix, a process for preparing them and their uses, in particular the use in hydrometallurgy and electroplating.

Abstract: The present application relates to novel monodisperse, gel-type or macroporous picolylamine resins which are based on at least one monovinylaromatic compound and at least one polyvinylaromatic compound and/or a (meth)acrylic compound and contain tertiary nitrogen atoms in structures of the general formula (I) as functional group, where R1 is an optionally substituted radical from the group consisting of picolyl, methylquinoline and methylpiperidine, R2 is a radical —(CH2)q—COOR3, R3 is a radical from the group consisting of H, Na and K, m is an integer from 1 to 4, n and p are each, independently of one another, a number in the range from 0.1 to 1.9 and the sum of n and p is 2, q is an integer from 1 to 5 and M is the polymer matrix, a process for preparing them and their uses, in particular the use in hydrometallurgy and electroplating.

Abstract: The oxine ligands 5-chloro-8-hydroxyquiniline and 5-sulfoxyl-8-hydroxyquinoline are covalently bound, using, for example, the Mannich reaction, to a silica gel polyamine composite made from a silanized amorphous silica xerogel and polyallylamine. The resulting modified composites, termed CB-1 (X?Cl) and SB-1 (X?SO3H), respectively, show a clear selectivity for trivalent over divalent ions and selectivity for gallium over aluminum. The compounds of the invention can be applied for the sequestration of metals, such as heavy metals, from contaminated mine tailing leachates.

Abstract: A method for extracting zinc from an aqueous ammoniacal zinc solution containing impurities, the method comprising the steps of: (i) contacting the aqueous ammoniacal zinc solution containing impurities with an organic phase comprising an ammonium salt of an organic extractant dissolved in a hydrophobic diluent, allowing transfer of the zinc to the organic phase and transfer of ammonium to the aqueous phase, thereby providing a zinc-enriched, ammonium-depleted organic phase and an ammonium-enriched, zinc-depleted aqueous phase containing impurities; (ii) separating the zinc-enriched, ammonium-depleted organic phase from the ammonium-enriched, zinc-depleted aqueous phase containing impurities; (iii) contacting the zinc-enriched, ammonium-depleted organic phase with an aqueous solution containing positively charged species, allowing transfer of the zinc from the organic phase and transfer of positively charged species from the aqueous phase, thereby providing an aqueous zinc solution and an organic phase con

Abstract: Provided are methods using ketoximes and/or aldoximes, including 3-methyl-5-alkylsalicylaldoxime and/or 3-methyl-5-alkyl-2-hydroxyacetophenone oxime, in reagent compositions for metal extraction/isolation. One such method is of extracting a metal from a nitrate-containing aqueous solution. Another such method is of extracting a metal from an aqueous ammoniacal solution. A third method is of multi-metal extraction based on a predetermined pH.

Abstract: A method for extracting zinc from an aqueous ammoniacal zinc solution containing impurities, the method comprising the steps of: (i) contacting the aqueous ammoniacal zinc solution containing impurities with an organic phase comprising an ammonium salt of an organic extractant dissolved in a hydrophobic diluent, allowing transfer of the zinc to the organic phase and transfer of ammonium to the aqueous phase, thereby providing a zinc-enriched, ammonium-depleted organic phase and an ammonium-enriched, zinc-depleted aqueous phase containing impurities; (ii) separating the zinc-enriched, ammonium-depleted organic phase from the ammonium-enriched, zinc-depleted aqueous phase containing impurities; (iii) contacting the zinc-enriched, ammonium-depleted organic phase with an aqueous solution containing positively charged species, allowing transfer of the zinc from the organic phase and transfer of positively charged species from the aqueous phase, thereby providing an aqueous zinc solution and an organic phase contai

Abstract: A method for selective removal of cadmium from a feed solution also containing other metals such as nickel (Ni) and/or cobalt (Co), utilizing a thiourea based ion exchange resin, and a method for eluting cadmium adsorbed on the thiourea based resin.

Abstract: The subject of the present disclosure is a multi-column sequenced separation process and a drive for implementing this process. The disclosure applies particularly to the separation of metal derivatives such as uranium, nickel, copper, cobalt and other precious metals present in leaching effluents in hydrometallurgical processes.

Abstract: The present application relates to novel gel-type or macroporous picolylamine resins which are based on at least one monovinylaromatic compound and at least one polyvinylaromatic compound and/or a (meth)acrylic compound and contain tertiary nitrogen atoms in structures of the general formula (I) as functional group, where R1 is an optionally substituted radical from the group consisting of picolyl, methylquinoline and methylpiperidine, R2 is —CH2—S—CH2COOR3 or —CH2—S—C1-C4-alkyl or —CH2—S—CH2CH(NH2)COOR3 or —CH2—S—CH2—CH(OH)—CH2(OH) or or derivatives thereof or —C?S(NH2), R3 is a radical from the group consisting of H, Na and K, m is an integer from 1 to 4, n and p are each, independently of one another, a number in the range from 0.1 to 1.9 and the sum of n and p is 2 and M is the polymer matrix, a process for preparing them and their uses, in particular the use in hydrometallurgy and electroplating.

Abstract: A nanopore reactive adsorbent composite material, which may be a porous adsorbent comprising a chemically surface face modified gel, has a composition and micro structure, which integrals ion exchange components such as hydroxy apatite.

Abstract: The present disclosure is directed towards systems and methods for the treatment of wastewater. A system in accordance with one particular embodiment may include a vacuum filter band system configured to receive a saturated resin tank from a front end system, the vacuum filter band system configured to generate a slurry from the saturated resin tank and to provide a cascading resin rinse to the slurry. The system may further include a repetitive stripping system configured to receive a metal-filled purification unit from a metal specific purification system. The repetitive stripping system may be further configured to sequentially apply the contents of a plurality of acid tanks to the metal-filled purification unit to generate a metal salt. Numerous other embodiments are also within the scope of the present disclosure.

Abstract: The present invention relates to a method and system for recovery of waste.

Abstract: The purpose of the invention is to remove copper selectively from a concentrated zinc sulphate solution by ion exchange. The method enables a significant reduction in the use of zinc powder during the solution purification of zinc sulphate solution and makes possible to avoid usage of arsenic or antimony trioxides as a precipitation chemical. The method is to be combined with the chloride removal that occurs as a sub-stage of solution purification.

Abstract: Mercury is removed from contaminated waste by firstly applying a sulfur reagent to the waste. Mercury in the waste is then permitted to migrate to the reagent and is stabilized in a mercury sulfide compound. The stable compound may then be removed from the waste which itself remains in situ following mercury removal therefrom.

Abstract: It is an object to provide a method for producing stable alkaline metal oxide sols having a uniform particle size distribution. The method comprises the steps of: heating a metal compound at a temperature of 60° C. to 110° C. in an aqueous medium that contains a carbonate of quaternary ammonium; and carrying out hydrothermal processing at a temperature of 110° C. to 250° C. The carbonate of quaternary ammonium is (NR4)2CO3 or NR4HCO3 in which R represents a hydrocarbon group, or a mixture thereof. The metal compound is one, or two or more metal compounds selected from a group of compounds based on a metal having a valence that is bivalent, trivalent, or tetravalent.

Abstract: A separation medium, a method for using that separation medium and an apparatus for selectively extracting multivalent cations such as pseudo-lanthanide, prelanthanide, lanthanide, preactinide or actinide cations from an aqueous acidic sample solution is described. The separation medium is preferably free-flowing and comprises particles having a diglycolamide (DGA) extractant dispersed onto an inert, porous support.

Abstract: A separation medium, a method for using that separation medium and an apparatus for selectively extracting multivalent cations such as pseudo-lanthanide, prelanthanide, lanthanide, preactinide or actinide cations from an aqueous acidic sample solution is described. The separation medium is preferably free-flowing and comprises particles having a diglycolamide (DGA) extractant dispersed onto an inert, porous support.

Abstract: Niobate-based octahedral molecular sieves having significant activity for multivalent cations and a method for synthesizing such sieves are disclosed. The sieves have a net negatively charged octahedral framework, comprising niobium, oxygen, and octahedrally coordinated lower valence transition metals. The framework can be charge balanced by the occluded alkali cation from the synthesis method. The alkali cation can be exchanged for other contaminant metal ions. The ion-exchanged niobate-based octahedral molecular sieve can be backexchanged in acidic solutions to yield a solution concentrated in the contaminant metal. Alternatively, the ion-exchanged niobate-based octahedral molecular sieve can be thermally converted to a durable perovskite phase waste form.

Abstract: A silica-polyamine based extraction material removes selected transition metal ions from solution in the presence of iron ions. The silica-polyamine base is a reaction product of a polyamine and a covalently anchored trifunctional hydrocarbylsilyl that yields non-crosslinked amino groups to which pyridine function group is attached. The extraction material is particularly useful in selectively removing copper from low concentration, low pH leach solutions separating copper from ferric iron or chloride ions. The product is a durable, high capacity extraction material that selectively captures copper at high flow rates and releases that copper into highly concentrated solutions.

Abstract: A method for producing an indium-containing aqueous solution having a reduced amount of metal impurities is provided. A method for producing an indium-containing aqueous solution having a reduced amount of metal impurities which comprises bringing an aqueous solution containing indium and metal impurities whose hydrogen ion concentration is adjusted at 0.5 mol/L to 3 mol/L into contact with a non-chelate ion-exchange resin to remove the metal impurities, and a method for producing an indium-containing aqueous solution having a reduced amount of metal impurities which comprises bringing an aqueous solution containing indium and metal impurities into contact with a chelate ion-exchange resin to remove the metal impurities are provided.

Abstract: A nanoporous reactive adsorbent incorporates a relatively small number of relatively larger reactant, e.g., metal, enzyme, etc., particles (10) forming a discontinuous or continuous phase interspersed among and surrounded by a continuous phase of smaller adsorbent particles (12) and connected interstitial pores (14) therebetween. The reactive adsorbent can effectively remove inorganic or organic impurities in a liquid by causing the liquid to flow through the adsorbent. For example, silver ions may be adsorbed by the adsorbent particles (12) and reduced to metallic silver by reducing metal, such as ions, as the reactant particles (10). The column can be regenerated by backwashing with the liquid effluent containing, for example, acetic acid.

Abstract: A process of recovering metals from waste lithium ion/Ni—H/Ni—Cd batteries, wherein the waste batteries are calcined and sieved to generate an ash containing metals and metal oxides. The process includes subjecting the ash to a first dissolution etching treatment, a first filtration treatment to obtain a filtrate containing Cd ions which are crystallized as cadmium sulfate, a second dissolution etching treatment for the filtered solid, and a second filtration treatment to obtain a second filtrate. Fe+3, Al+3 and rare earth metal ions in the second filtrate are precipitated as hydroxides by adding a base to the second filtrate. The remaining solution was extracted and counter-extracted to obtain aqueous solutions of Co and Ni ions, which were subjected separately to a electrolysis to deposit Co and Ni metals. Li ions in the residue solution from the electrolysis of Ni was precipitated as carbonate by adding a soluble carbonate salt.

Abstract: The invention relates to a concentration device using magnetic particles and a method therefor aimed at performing concentration of a large volume of liquid efficiently and reliably with a simple structure and on a small device scale. The construction involves having: a liquid suction passage in which liquid can pass through only in a suction direction; a liquid discharge passage in which liquid can pass through only in a discharge direction; a magnetic force device which can exert a magnetic field from outside of the liquid passage on at least one liquid passage thereof or remove the magnetic field, and which can separate magnetic particles having directly or indirectly captured a target substance suspended in the liquid by having the magnetic particles adhere to the inner wall of the liquid passage; a storage section communicated with each liquid passage, for storing the sucked liquid; and a pressure adjustment device for sucking and discharging the liquid by adjusting the pressure in the storage section.

Abstract: Improved methods are disclosed for the efficient and cost-effective recovery of zinc metal from zinc-containing brines. Zinc is first bound to an anionic ion exchange resin (IX) which has been equilibrated with a solution containing a reducing agent, washed, and eluted with an elution solution. A reducing agent can be added to the brine prior to loading on the IX and can optionally be added to the IX after the washing step. The eluted zinc is extracted with a water-immiscible cationic organic solvent (SX), which is scrubbed, then stripped with concentrated acid. Substantially pure zinc is recovered by electrowinning the zinc-loaded concentrated acid solution.

Abstract: Compositions and methods for selectively binding metal ions from a source solution comprise using a polyhydroxypyridinone-containing ligand covalently bonded to a particulate solid support through a hydrophilic spacer of the formula SS-A-X-L (HOPO)n where SS is a particulate solid support such as silica or a polymeric bead, A is a covalent linkage mechanism, X is a hydrophilic spacer grouping, L is a ligand carrier, HOPO is a hydroxypyridinone appropriately spaced on the ligand carrier to provide a minimum of six functional coordination metal binding sites, and n is an integer of 3 to 6 with the proviso that when SS is a particulate organic polymer, A-X may be combined as a single covalent linkage.

Abstract: The invention relates to a method for recovering non-ferrous metals, particularly nickel, cobalt, copper, zinc, manganese and magnesium, from materials containing said metals by converting said non-ferrous metals into sulphates by means of melt and melt coating sulphation, i.e. by a thermal treatment under oxidizing conditions within a temperature range of 400 to 800° C., during which a reaction mixture is formed containing at least one said non-ferrous metal, iron(III)sulphate and alkali metal sulphate, and appropriate reaction conditions are selected to substantially prevent iron(III)sulphate from thermally decomposing to hematite, and finally, said non-ferrous metals are recovered as metallic compounds. In the method of the invention, a process is formed around the melt and melt coating sulphation, which comprises nine steps.

Abstract: A method for reducing the formation of Zn(NH4)4Cl2 from ZnO/NH4Cl solutions formed during an industrial waste stream recycling method useful for the recovery of high purity zinc oxide products and other chemical and metal values from industrial waste streams.

Abstract: A thin film transistor includes a substrate, a gate electrode formed on the substrate, and including opposing edge portions and a middle portion. An insulating film is formed on the surface of the gate electrode having a greater thickness on one of the gate edge portions. An active region is formed on the surface of the insulating film and the exposed substrate. The active region includes an off-set regions a channel region, a source region, and a drain region.

Abstract: A method of removing HMO.sub.2.sup.- anions from an aqueous silicate solution comprising contacting the solution with a cationic ion exchange resin, where M is manganese, zinc, copper, nickel, or a mixture thereof. The method is particularly applicable to solutions of sodium silicate or potassium silicate.

Abstract: The present invention relates to methods for digesting diphosphonic acid substituted cation exchange resins that have become loaded with actinides, rare earth metals, or heavy metals, in a way that allows for downstream chromatographic analysis of the adsorbed species without damage to or inadequate elution from the downstream chromatographic resins. The methods of the present invention involve contacting the loaded diphosphonic acid resin with concentrated oxidizing acid in a closed vessel, and irradiating this mixture with microwave radiation. This efficiently increases the temperature of the mixture to a level suitable for digestion of the resin without the use of dehydrating acids that can damage downstream analytical resins. In order to ensure more complete digestion, the irradiated mixture can be mixed with hydrogen peroxide or other oxidant, and reirradiated with microwave radiation.

Abstract: The present invention relates to colloidal suspensions of discrete particles of colloidal zeolite and a method for preparing such zeolite from clear tetraalkylammonium stabilized aluminiumsilicate solutions. Smaller amounts of well defined and controlled metal hydroxide solutions are added to these alumiumsilicate solutions to enable the synthesis of a specific zeolite as well as to control zeolite yield. The colloidal suspensions are characterized by an average particle size of less than 250 nanometers and preferably, less than 200 nanometers together with the fact that the particle size distribution expressed as the geometric standard deviation is less than 1.30 and preferably less than 1.20. Zeolite sols synthesized according to this invention display Tyndall light scattering typical for colloidal suspensions as well as a very low rate of sedimentation due to the small particle size.

Abstract: The present invention, relates to the recovery of zinc values from an acidic solution containing hydrocyanic acid. The zinc is recovered as complex zinc cyanide anions which may, if desired, be recycled for the (selective) preliminary removal or separation of adsorbed copper values from an (strong or weak base) anion exchange material, the anion exchange material additionally being loaded with adsorbed cyanide complexes of precious metal values such as gold and silver. The invention, further relates to the recovery of cyanide values associated with copper cyanide complexes which are adsorbed on or taken up by an (strong or weak base) anion exchange material; the recovered cyanide values, for example, being available for recycling to a cyanide leach stage for leaching additional metal values from an ore or the like.

Abstract: The invention relates to a process for the recovery of raw materials from presorted collected waste, especially scrap electrochemical batteries and accumulators in which the scrap (10)is first mechanically prepared and divided into coarse and fine fractions (15, 16) which are further processed separately. Materials to be recovered are extracted by dissolution in steps by a first and a second solvent in a wet chemical preparation process from the fine fraction and then recovered individually from the two solutions.

Abstract: The invention is for a process of removal of dissolved heavy metal cation contaminants from an organic solution. The process of the invention involves providing a chelating ion exchange resin modified by removal of sodium ions therefrom and contacting said organic solution with said modified exchange resin for a time sufficient to remove ionic metal impurities. The invention is useful for removal of ionic contaminants from organic solutions requiring high purity.

Abstract: Liquid phase hydrocarbon fractions of wet natural gas streams which have been in contact while in the liquid phase with mineral particles entrained in the natural gas stream as it is recovered from the wellhead are found to contain a suspension of such particles. These particles contain loosely bound mercury which is capable of contaminating other constituents of the natural gas stream which come into contact with the particles. Effective procedures to purify such wet natural gas streams must include removal of the mineral particles as well as the element mercury dissolved in the liquid phase hydrocarbons or admixed with the vapor phase hydrocarbons.

Abstract: A method of adsorbing and separating a heavy metal element by using a tannin adsorbent comprising:(a) adjusting the pH of a solution containing a plurality of heavy metal elements to a predetermined pH;(b) contacting the adsorbent with the solution in which the pH thereof is adjusted;(c) adjusting the pH of the solution contacted with the adsorbent to a pH different from the predetermined pH; and(d) contacting the solution in which the pH thereof is adjusted at the step (d) with the adsorbent prepared at the step (a).According to the inventive method, all of the heavy metal elements can be efficiently separated and adsorbed by using a tannin adsorbent from a solution containing a number of heavy metal elements. A method of regenerating a tannin adsorbent are also disclosed.