CA2217866A1 - Polymer sorbent for ion recovery processes - Google Patents
Polymer sorbent for ion recovery processes Download PDFInfo
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- CA2217866A1 CA2217866A1 CA002217866A CA2217866A CA2217866A1 CA 2217866 A1 CA2217866 A1 CA 2217866A1 CA 002217866 A CA002217866 A CA 002217866A CA 2217866 A CA2217866 A CA 2217866A CA 2217866 A1 CA2217866 A1 CA 2217866A1
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- polymeric foam
- foam
- cells per
- coarse
- open cell
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
- C22B3/20—Treatment or purification of solutions, e.g. obtained by leaching
- C22B3/42—Treatment or purification of solutions, e.g. obtained by leaching by ion-exchange extraction
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J39/00—Cation exchange; Use of material as cation exchangers; Treatment of material for improving the cation exchange properties
- B01J39/08—Use of material as cation exchangers; Treatment of material for improving the cation exchange properties
- B01J39/16—Organic material
- B01J39/18—Macromolecular compounds
- B01J39/19—Macromolecular compounds obtained otherwise than by reactions only involving unsaturated carbon-to-carbon bonds
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J41/00—Anion exchange; Use of material as anion exchangers; Treatment of material for improving the anion exchange properties
- B01J41/08—Use of material as anion exchangers; Treatment of material for improving the anion exchange properties
- B01J41/12—Macromolecular compounds
- B01J41/13—Macromolecular compounds obtained otherwise than by reactions only involving unsaturated carbon-to-carbon bonds
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
- Water Treatment By Sorption (AREA)
- Treatment Of Liquids With Adsorbents In General (AREA)
Abstract
A process for the selective removal of ions from dispersion of solids in solutions and which also relates to coarse open cell polymeric foams which support ion exchange sites. The process for the selective removal of ions from a solution having solid materials dispersed therein comprises passing the solution having solid materials dispersed therein through a bed of coarse open cell polymeric foam having ion exchange sites. The ion-selective coarse open cell polymeric foam has a cell size sufficient to allow solutions having solids dispersed therein to pass through said foam.
Description
POLYMER SORBENT FOR ~ON RECOVERY PROC'F..~.~F..C
~ he present invention relates to a process for the removal of ions from slurries, pulps or other dispersions of solids in liquids. In particular, the present S invention relates to a process for the selective removal of ions from dispersion of solids in solutions and also relates to coarse open cell polymeric foams which support ion ~Y h~nge sites.
The selective removal of ions from solution is an important process in many 10 industries. In conventional ion recovery or removal processes ions, are removed from solutions by the use of processes such as ion çyrh~nge onto solid beads or fibres, membrane processes, activated carbon adsorption, preririt~tinn> solvent extraction, ion flotation and the like. The removal of ions from solutions ~,vhich also contain solid materials dispersed throughout such as in slurries, pulps and the like 15 is more difficult. The applic~tion of ion rY~h~nge resins and activated carbon is widely practiced throughout many industries inrl~ ing the minerals processing industry where selective removal of ions from slurries is necessary and has become the method of choice in the recovery of gold by cy~nicl~tion and in the recovery of uranium as the uranyl slllph~te, for eY~mple.
In order to achieve good recovery of desired ions from a solution it is desirable to provide a uniform distribution of solid sorbents such as ion eyrh~nge resins or activated carbon in the solution. This requires that the density of the solid sorbent be close to the density of the solution otherwise the added ion ~Y~h~n~e25 beads or the activated carbon will sink or float within the solution. Good recovery of ions from solutions having solid materials dispersed therein also requires that the sorption medium is uniformly distributed throughout. In order to achieve efficient recovery of the desired ions it is necessary to provide a sufficient concentration of solid sorbents in the solution, whether or not solid materials are dispersed in the 30 solution. The concentration of solid sorbents is generally limited by the presence of solid particles in solution. For .oY~m~le, the density of the solid sorbents desirably matches or at least a~rnxii--~tçs the pulp density which is only -CA 022l7866 l997-lO-09 determined by the ratio of mass of the solid particles to the solution. The density of the solid particles cannot be modified, nor is it generally possible to significantly change the density of the solution.
S Extractive metallurgical terhniques generally seek to obtain metal values from ores or concentrates. In order to achieve separation, the solids may be introduced into a reactor together with requisite lixiviants to dissolve the metal values and in doing so, typically produces a slurry. In such processes, other ions may also be brought into solution. Thus, a material which can selectively removeor recover the desired ion is added to the slurry usually in the form of a solidsorbent dispersed in the slurry. Alternatively, the sollltion cont~ining the dissolved ions is separated from the solid materials and the metal ions are then recovered or removed from the clarifled soll~tion The m~imi7~tion of plant capacity in such processes requires a high proportion of solids in the sld~ cor~,istent~w,th good rn~r.g ar.d pllmping ~n.dh~n~lling properties. Thus, in order to attempt to distribute the solid sorbentsuniformly throughout the slu~y, high intensity mixing is often used. This rapid shearing action generated in the reactor can lead to destruction of the active solid sorbent by attrition and breakage. This breakage can result in the loss of valuable ions into the discharge from the plant along with the slurry.
The solid sorbent is typically recovered from the slurry or from the solution by screening. In the case of ion eyrh~nge resins the particle size of the resin is selected in a size range which is generally fine enough to exhibit desirable loading and elution kinetics. Fine ion eyrh~nge beads are more difficult to recover fromthese pulps because the screen opening size employed must be greater than the particles m~king up the slurry, but smaller than that of the ~m~llest ion elrrh~nge beads. For example, in U.S. Patent 5,198,021 the ion e~rh~nge resin bead size ispreferentially recommended to be between 6 and 12 mesh. "Blinding", or screen blocking can thus readily occur.
CA 022l7866 l997-lO-09 Additionally, ion ~ h~n~e resin beads suffer from the problem of osmotic shock. Thus, swelling and shrinkage of the ion .oYrh~nge resin bead during loading and stripping of the metal ions cont~in~cl thereon can lead to resin breakage.
We have now found that solutions cont~ining solid materials dispersed therein may be passed through coarse open cell polymeric foams having ion to~r~h~nge sites incorporated into the open cell polymeric foam and the selective removal of ions from solution may be achieved. Accordingly, there is provided a process for the selective removal of ions from a solution having solid materialsdispersed therein comprising passing the solution having solid materials dispersed therein through a bed of coarse open cell polymeric foam having ion ~Y ~h~nge sites.
Suitable coarse open cell polymeric foams inc~hlde coarse cell polyurethanes and ~l ef~;l ably coarse cell retic~ te~l polyurethanes. Polyurethane-based polymers are recognised for their high abrasion resistance. These polyurethane-based polymers have also been modified to incorporate ion ~Y~ h~ngin~ sites as described in PCT/AU93/00312 and PCT/AU94/00793 incorporated herein by reference and also include any polymeric resin which has been provided with a suitable function~lity for the sorption of the desired ion either by interpenetration by a second polymer (such second polymer typically as described in South African Patent ZA 89/2733 and Canad. Patent Application 2,005,259) with or without further chemical modification, polyurethane polymer chemical modification, organic extractant impregn~tion such as described by Lin et al in U.S. Patents 4,814,007, 4,895,597, 4,992,200, 5,028,259, U.K. Patent G.B.2,186,563A and P~-l WO93/19212 and Virnig in U.S. Patents 5,198,021 and 5,340,380 or known to those skilled in the applic~tion of liquid ion ~Yrh~n~e extr~rt~ntc, etc. These polyurethane-based polymers can be produced in a variety of forms such as beads or fibres, but can also be expanded to produce flexible, semiflexible and rigid foams. Blocks of foams several cubic metres in size may be produced. Larger blocks can be pro~ e-l by well established bonding processes. These blocks of foam can be cut to any suitable shape and size dependent upon the requisite application. Alternatively, blocks of foam can be produced to the desired size and shape by pouring the liquid foaming reagents into a suitable mould and after the reaction has reached a suitable degree of curing, removing the item from the mould.
The polyurethane foams are preferably flexible and can either be polyester-5 based or polyether-based. Polyether-based polyurethane foams are generally preferred because of their ~lemon~trated improved chemical resi~t~n~e over the ester foams. Huw~vel, for some specific applications ester foams may possess suitable properties. The polyether-based foams may be produced by the reaction under controlled conditions of a suitable polyol or blend of polyols with one or10 more diisocyanates in the presence of catalysts, cell control agents and, if required, fillers, flame retardants, etc. The polyols are usually based upon the reaction of di-or higher functional materials with ethylene oxide (EO), propylene oxide (PO), or mixtures of these two oxides. For flexible polyurethane foams, gly~;eli~le is one preferred starting material and this is reacted with EO and/or PO to produce a 15 polyol with a molecular weight generally in the range of 3000 to 6000. The diisocyanate is generally toll-~ ne diisocyanate (T~I) or diphenylmethane-4,4'-diisocyanate-based materials (MDI), but is not limite~l to these two isocyanates.
Polyurethane foams may be "retic~ ted", that is, most or all of the residual 20 "windows" or cell walls are removed by such processes as have been described by Volz in U.S. Patent No. 3,171,820 and by Green in U.S. Patent Nos. 3,175,025 and3,175,030 and which are well known to those skilled in the pro~ ction or fabrication of polyurethane foams.
It has been found that these reticnl~te-l polymeric polyurethane foams are able to have solutions c~nl~lisi lg solid materials, such as pulps or slurries similar in composition to those found in the minerals processing industry very rapidly pumped through them without any indication of blorking Fine-celled flexible polyurethane foams under the same conditions are rapidly blocked by the solid materials thus ~lcvt;lltillg the slurry from continlling to flow freely through the polyurethane foam.
_ 5 _ The selection of cell size in the polymeric foarn is depen~lent on the largest particle size of the solid materials contained in the solution. It is ~lef~:lled that the cell si_e be at least three limes the largest particle size of solid materials in the solution. In the mining industry slurries cont~ining metal ions in solution in 5 addition to solid particulate ore residues are common and we have found it preferable that the polymeric foam has a cell size in the range of from 45 cells per linear inch (180 cells per 100mm) to less than 15 cells per linear inch (60 cells per 100mm). It is desirable to select a cell size wherein the surface area of the polymeric foam is m~imi7ecl without resulting in blocking of the foam with the 10 solid particles from the sollltion The introduction of these coarse open cell polymeric foams having ion ~h~nging sites into a reactor in the form of a fixed-bed such as the p~t~hllc~c used in the gold cy~nid~tion industry provides a process for ensuring that the ion 15 f~Yrh~n ing material is much more u~irollllly distributed throughout the slurry or pulp and has a large ~co.ccible surface area. This means that the sol-~tion is able to better contact the ion ~ h~nging sites, uv~rcollles screening problems, reduces the need for intensive mixing and reduces the loss of valuable metal ions to thetailings dischOEge.
Beds of coOEse open cell polymeric foams cont~inin~ the desired lig~n-ls may be housed in suitably co~ ucted vessels. Such vessels may be designed to allow liquid cont~ining solid materials to pass through the polymeric foam either by gravity or by ~ i . .g or by other means and provides an impl uv~:d recovery system 25 for the desired ions. Solutions cont~ining from less than 15% of solids to over 50%
by weight of solids and vOEying in pOEticle size from less than 45 micron to greater than 150 micron have been contilluously pumped or passed through coarse open cell polymeric foams.
Flexible polymeric foams may be able to undergo repe~ted flexing and th~l~role the additional possibility of applying a me~h~nic~l pulsing action to the foam bed is achieved.
CA 02217866 1997-lo-o9 The polymeric foam comprises ion loxrh~nge sites. These sites may be provided in the initial manufacturing process of the polymeric foam or may be provided by modification of the foam after its initial manufacture. The selection of a~l!.u~liate functional groups at the ion eY~h~nge sites allows the selective5 recovery of a broad range of ions in solution. For .ox~mrle the polymeric foam may have ion .ox~h~nge functionality for the selective removal of heavy metals in~ cling arsenic, c~lmil-m, chromium, iron, zinc and mercury; precious metals in~ ling gold, silver, rl~timlm, p~ llm, rhodium, iridium, ruthenium and o~mi~lm; other anions and cations including h ~ les, sulfates, nitrates, cyanides, thiocyanates, 10 cyanogen, carbonates and phosphates.
In certain metal ion recovery processes, oxygen may be required as part of the chemical reaction, for ~x~mrle in the dissolution of gold in oxygenated ~lk~linto sodium cyanide solution. These coarse and open cell polymeric foams will allow 15 the passage of both the solution, slurry and if required, air, oxygen or other gas.
The polymer foam in some cases may also assist by hll~luvillg the distribution of the gas throughout the solution, pulp or slurry.
In a second aspect the present invention provides an ion-selective coarse 20 open cell polymeric foam as hereinabove described in which the cell size is sufficient to allow solutions having solids dispersed therein to pass through said foam.
The present invention will be hereinafter described with lefe~ellce to 25 retic ll~tecl polyurethane foams, huw~v~ , it will be understood that other coarse open cell polymeric foams will be equally suited.
In the gold industry, the loss of gold cyanide by adsorption of the aurocyanide anion onto the surfaces of clays, ~ rhi~le minerals, carbonaceous 30 materials, etc. is well recognised and has been termed "preg robbing". The shorter the path length which a metal ion needs to travel to be sorbed by the deliberately introduced selective metal ion sorbent, the less the O~Ol ~ y for "preg robbing"
~ he present invention relates to a process for the removal of ions from slurries, pulps or other dispersions of solids in liquids. In particular, the present S invention relates to a process for the selective removal of ions from dispersion of solids in solutions and also relates to coarse open cell polymeric foams which support ion ~Y h~nge sites.
The selective removal of ions from solution is an important process in many 10 industries. In conventional ion recovery or removal processes ions, are removed from solutions by the use of processes such as ion çyrh~nge onto solid beads or fibres, membrane processes, activated carbon adsorption, preririt~tinn> solvent extraction, ion flotation and the like. The removal of ions from solutions ~,vhich also contain solid materials dispersed throughout such as in slurries, pulps and the like 15 is more difficult. The applic~tion of ion rY~h~nge resins and activated carbon is widely practiced throughout many industries inrl~ ing the minerals processing industry where selective removal of ions from slurries is necessary and has become the method of choice in the recovery of gold by cy~nicl~tion and in the recovery of uranium as the uranyl slllph~te, for eY~mple.
In order to achieve good recovery of desired ions from a solution it is desirable to provide a uniform distribution of solid sorbents such as ion eyrh~nge resins or activated carbon in the solution. This requires that the density of the solid sorbent be close to the density of the solution otherwise the added ion ~Y~h~n~e25 beads or the activated carbon will sink or float within the solution. Good recovery of ions from solutions having solid materials dispersed therein also requires that the sorption medium is uniformly distributed throughout. In order to achieve efficient recovery of the desired ions it is necessary to provide a sufficient concentration of solid sorbents in the solution, whether or not solid materials are dispersed in the 30 solution. The concentration of solid sorbents is generally limited by the presence of solid particles in solution. For .oY~m~le, the density of the solid sorbents desirably matches or at least a~rnxii--~tçs the pulp density which is only -CA 022l7866 l997-lO-09 determined by the ratio of mass of the solid particles to the solution. The density of the solid particles cannot be modified, nor is it generally possible to significantly change the density of the solution.
S Extractive metallurgical terhniques generally seek to obtain metal values from ores or concentrates. In order to achieve separation, the solids may be introduced into a reactor together with requisite lixiviants to dissolve the metal values and in doing so, typically produces a slurry. In such processes, other ions may also be brought into solution. Thus, a material which can selectively removeor recover the desired ion is added to the slurry usually in the form of a solidsorbent dispersed in the slurry. Alternatively, the sollltion cont~ining the dissolved ions is separated from the solid materials and the metal ions are then recovered or removed from the clarifled soll~tion The m~imi7~tion of plant capacity in such processes requires a high proportion of solids in the sld~ cor~,istent~w,th good rn~r.g ar.d pllmping ~n.dh~n~lling properties. Thus, in order to attempt to distribute the solid sorbentsuniformly throughout the slu~y, high intensity mixing is often used. This rapid shearing action generated in the reactor can lead to destruction of the active solid sorbent by attrition and breakage. This breakage can result in the loss of valuable ions into the discharge from the plant along with the slurry.
The solid sorbent is typically recovered from the slurry or from the solution by screening. In the case of ion eyrh~nge resins the particle size of the resin is selected in a size range which is generally fine enough to exhibit desirable loading and elution kinetics. Fine ion eyrh~nge beads are more difficult to recover fromthese pulps because the screen opening size employed must be greater than the particles m~king up the slurry, but smaller than that of the ~m~llest ion elrrh~nge beads. For example, in U.S. Patent 5,198,021 the ion e~rh~nge resin bead size ispreferentially recommended to be between 6 and 12 mesh. "Blinding", or screen blocking can thus readily occur.
CA 022l7866 l997-lO-09 Additionally, ion ~ h~n~e resin beads suffer from the problem of osmotic shock. Thus, swelling and shrinkage of the ion .oYrh~nge resin bead during loading and stripping of the metal ions cont~in~cl thereon can lead to resin breakage.
We have now found that solutions cont~ining solid materials dispersed therein may be passed through coarse open cell polymeric foams having ion to~r~h~nge sites incorporated into the open cell polymeric foam and the selective removal of ions from solution may be achieved. Accordingly, there is provided a process for the selective removal of ions from a solution having solid materialsdispersed therein comprising passing the solution having solid materials dispersed therein through a bed of coarse open cell polymeric foam having ion ~Y ~h~nge sites.
Suitable coarse open cell polymeric foams inc~hlde coarse cell polyurethanes and ~l ef~;l ably coarse cell retic~ te~l polyurethanes. Polyurethane-based polymers are recognised for their high abrasion resistance. These polyurethane-based polymers have also been modified to incorporate ion ~Y~ h~ngin~ sites as described in PCT/AU93/00312 and PCT/AU94/00793 incorporated herein by reference and also include any polymeric resin which has been provided with a suitable function~lity for the sorption of the desired ion either by interpenetration by a second polymer (such second polymer typically as described in South African Patent ZA 89/2733 and Canad. Patent Application 2,005,259) with or without further chemical modification, polyurethane polymer chemical modification, organic extractant impregn~tion such as described by Lin et al in U.S. Patents 4,814,007, 4,895,597, 4,992,200, 5,028,259, U.K. Patent G.B.2,186,563A and P~-l WO93/19212 and Virnig in U.S. Patents 5,198,021 and 5,340,380 or known to those skilled in the applic~tion of liquid ion ~Yrh~n~e extr~rt~ntc, etc. These polyurethane-based polymers can be produced in a variety of forms such as beads or fibres, but can also be expanded to produce flexible, semiflexible and rigid foams. Blocks of foams several cubic metres in size may be produced. Larger blocks can be pro~ e-l by well established bonding processes. These blocks of foam can be cut to any suitable shape and size dependent upon the requisite application. Alternatively, blocks of foam can be produced to the desired size and shape by pouring the liquid foaming reagents into a suitable mould and after the reaction has reached a suitable degree of curing, removing the item from the mould.
The polyurethane foams are preferably flexible and can either be polyester-5 based or polyether-based. Polyether-based polyurethane foams are generally preferred because of their ~lemon~trated improved chemical resi~t~n~e over the ester foams. Huw~vel, for some specific applications ester foams may possess suitable properties. The polyether-based foams may be produced by the reaction under controlled conditions of a suitable polyol or blend of polyols with one or10 more diisocyanates in the presence of catalysts, cell control agents and, if required, fillers, flame retardants, etc. The polyols are usually based upon the reaction of di-or higher functional materials with ethylene oxide (EO), propylene oxide (PO), or mixtures of these two oxides. For flexible polyurethane foams, gly~;eli~le is one preferred starting material and this is reacted with EO and/or PO to produce a 15 polyol with a molecular weight generally in the range of 3000 to 6000. The diisocyanate is generally toll-~ ne diisocyanate (T~I) or diphenylmethane-4,4'-diisocyanate-based materials (MDI), but is not limite~l to these two isocyanates.
Polyurethane foams may be "retic~ ted", that is, most or all of the residual 20 "windows" or cell walls are removed by such processes as have been described by Volz in U.S. Patent No. 3,171,820 and by Green in U.S. Patent Nos. 3,175,025 and3,175,030 and which are well known to those skilled in the pro~ ction or fabrication of polyurethane foams.
It has been found that these reticnl~te-l polymeric polyurethane foams are able to have solutions c~nl~lisi lg solid materials, such as pulps or slurries similar in composition to those found in the minerals processing industry very rapidly pumped through them without any indication of blorking Fine-celled flexible polyurethane foams under the same conditions are rapidly blocked by the solid materials thus ~lcvt;lltillg the slurry from continlling to flow freely through the polyurethane foam.
_ 5 _ The selection of cell size in the polymeric foarn is depen~lent on the largest particle size of the solid materials contained in the solution. It is ~lef~:lled that the cell si_e be at least three limes the largest particle size of solid materials in the solution. In the mining industry slurries cont~ining metal ions in solution in 5 addition to solid particulate ore residues are common and we have found it preferable that the polymeric foam has a cell size in the range of from 45 cells per linear inch (180 cells per 100mm) to less than 15 cells per linear inch (60 cells per 100mm). It is desirable to select a cell size wherein the surface area of the polymeric foam is m~imi7ecl without resulting in blocking of the foam with the 10 solid particles from the sollltion The introduction of these coarse open cell polymeric foams having ion ~h~nging sites into a reactor in the form of a fixed-bed such as the p~t~hllc~c used in the gold cy~nid~tion industry provides a process for ensuring that the ion 15 f~Yrh~n ing material is much more u~irollllly distributed throughout the slurry or pulp and has a large ~co.ccible surface area. This means that the sol-~tion is able to better contact the ion ~ h~nging sites, uv~rcollles screening problems, reduces the need for intensive mixing and reduces the loss of valuable metal ions to thetailings dischOEge.
Beds of coOEse open cell polymeric foams cont~inin~ the desired lig~n-ls may be housed in suitably co~ ucted vessels. Such vessels may be designed to allow liquid cont~ining solid materials to pass through the polymeric foam either by gravity or by ~ i . .g or by other means and provides an impl uv~:d recovery system 25 for the desired ions. Solutions cont~ining from less than 15% of solids to over 50%
by weight of solids and vOEying in pOEticle size from less than 45 micron to greater than 150 micron have been contilluously pumped or passed through coarse open cell polymeric foams.
Flexible polymeric foams may be able to undergo repe~ted flexing and th~l~role the additional possibility of applying a me~h~nic~l pulsing action to the foam bed is achieved.
CA 02217866 1997-lo-o9 The polymeric foam comprises ion loxrh~nge sites. These sites may be provided in the initial manufacturing process of the polymeric foam or may be provided by modification of the foam after its initial manufacture. The selection of a~l!.u~liate functional groups at the ion eY~h~nge sites allows the selective5 recovery of a broad range of ions in solution. For .ox~mrle the polymeric foam may have ion .ox~h~nge functionality for the selective removal of heavy metals in~ cling arsenic, c~lmil-m, chromium, iron, zinc and mercury; precious metals in~ ling gold, silver, rl~timlm, p~ llm, rhodium, iridium, ruthenium and o~mi~lm; other anions and cations including h ~ les, sulfates, nitrates, cyanides, thiocyanates, 10 cyanogen, carbonates and phosphates.
In certain metal ion recovery processes, oxygen may be required as part of the chemical reaction, for ~x~mrle in the dissolution of gold in oxygenated ~lk~linto sodium cyanide solution. These coarse and open cell polymeric foams will allow 15 the passage of both the solution, slurry and if required, air, oxygen or other gas.
The polymer foam in some cases may also assist by hll~luvillg the distribution of the gas throughout the solution, pulp or slurry.
In a second aspect the present invention provides an ion-selective coarse 20 open cell polymeric foam as hereinabove described in which the cell size is sufficient to allow solutions having solids dispersed therein to pass through said foam.
The present invention will be hereinafter described with lefe~ellce to 25 retic ll~tecl polyurethane foams, huw~v~ , it will be understood that other coarse open cell polymeric foams will be equally suited.
In the gold industry, the loss of gold cyanide by adsorption of the aurocyanide anion onto the surfaces of clays, ~ rhi~le minerals, carbonaceous 30 materials, etc. is well recognised and has been termed "preg robbing". The shorter the path length which a metal ion needs to travel to be sorbed by the deliberately introduced selective metal ion sorbent, the less the O~Ol ~ y for "preg robbing"
to occur. Also, it has been proposed that dil~lting the pulps to low solids content such as 15% solids content and lower, can also reduce "preg robbing" and thus increase metal ion recovery. The described fixed-bed of ligand-modified reti~ll~ted polyurethane foam provides a short path length for the metal ions to travel prior S to sorption. Additionally, these modified polymers do not catalyse the o~ tion of the sodium cyanide to cyanates or cyanogen as is the case for activated carbon.
The slurry pumped to tailings normally contains cyanide, as "free" cyanide or WAD
(weak acid dissociable) cyanide, thiocyanates, etc. Thus, the tailings pondage contains anions which are toxic to h~lm~n, animal and bird life and therefore 10 represent a significant el,vilo~ e-nt~l hazard. The presence of these toxic anions maywell prevent the return of these sands underg~oulld as mine fill because of the potential for the toxic ions to enter the water table.
An example of the industrial application for this technology would be as an 15 alternative for the process as described by Coltrinari in PCT W 087/00072 or the well known AVR and Cyanisorb processes for the recovery of free and WAD
cyanide from the CIP or CIL slurry prior to its depositlon in a tailings dam. Inthese processes, the slurry is acidified to provide a sol~ltion pH generally between 5 and 8 in order to convert the cyanide species to HCN. Large volumes of low velocity air are then passed through the pH-adjusted tailings in a packed tower to volatilise the HCN. The HCN gas is readsorbed in an ~lk~lint- solution and returned to the CIP/CIL circuit. The stripped slurry must have its pH readjustedto 10 to 11 prior to deposition in the t~ilin~ dam. This process clearly suffers from a number of disadvantages: the requirement for twice adjusting the pH of the entire slurry and the use of very large volumes of air to vol~tili~e the HCN formed.
The application of a fixed bed of a suitable reticulated polyurethane foam for cyanide recovery offers a number of economic and kinetic advantages as will be described. In the presently described process, the free cyanide is COllv~lled to a 30 WAD cyanide such as by the tre~tm~nt of the slurry with a metal or soluble metal salt in particular with copper or zinc ~lllph~te The slurry then passes through a suitable bed of a selected reti~l~te~l polyurethane foam which has been modified - - -to contain a suitable ligand. The complex metal cyanide ion is rapidly adsorbed onto the polyurethane foam and the cyanide-depleted slurry passes to the tailings dam without the need for any pH adjustment (other than that which may be required by any particular mining or ellvi~ol"llental guvell~.llent regulation 5 applicable to that mine). The loaded polyurethane foam column is acidified to generate HCN gas which is adsorbed in an ~lk~line solution. A suitable courier gas such as nitrogen or air may be required. The acid solution may be reused for further stripping. Thus, a closed circuit plant can be ~lçcign~l in which much cm~ller volumes of air and sol-ltionc are required. Alternatively, if a ligand capable 10 of sorbing the WAD cyanide has been used and which is capable of being elutedat high pH, then the WAD cyanide can be stripped from the column. HCN gas can be generated from the strip solution and sodium cyanide formed or alternatively sodium cyanide reformed by electrolysis in a suitably ~ cignecl electrolysis cell.
A further application for the technology would be for the removal of soluble salts in lignite and other coals or for the removal of dissolved metal salts from soils in soil remediation processes, again, by allowing the slurry cont~inins~ the metal ions to flow through a fixed bed of retic~ te~l polyurethane foam having ion ~y~h~ngesites to sorb the metal ions.
Throughout this spe~ific~ti-ln and the claims which follow, unless the context requires otherwise, the word "colll~lise", or variations such as "comprises" or "comprising", will be understood to imply the incl~lcion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.
The following ~Y~mples are given to describe typical potential applications of this new technology. All percentages are by weight except where otherwise shown.
_ g _ A slurry was prepared by distributing 40 parts by weight of ground quartz particles in 100 parts of water. 80% of the quartz particles were between 100 S micron and 150 micron in size, the re-m~in~ler lay between 45 micron and 100 micron in size. This slurry was pumped both dowl,w~s and also u~w~ds through a 1.2 metre high block of reti~ll~ted polyurethane foam at particle flow rates in excess of 1 cm per second with negligible pressure drop across the bed.
A slurry was prepared by distributing 40 parts by weight of a clay mineral in 100 parts of water. 80% of the clay particles passed through a 75 micron sieve.
The slurry was pumped u~w~ds through a 1.2 metre high block of reticnl~tecl 15 polyurethane foam at particle flow rates of up to 1 cm per second. Air was introduced into the base of the foam bed and rapidly travelled through it in a vertical direction without s~lhst~nti~l pressure drop.
PRELIMII'I~RY EXAMPLE 3 Brown coal was mixed with water in a high shear mixer to disperse the fibrous coal particles and to form a slurry cont~ining 30% solids. This slurry was pumped u~w;llds through a 1.2 metre high block of reti~ll~ted polyurethane foam cont~ining about 15 cells per linear inch (i.e., 60 cells per 100 mm) at particle flow 25 rates of up to 1 cm per second.
48.4 grams of a retiç~ ted polyurethane foam cont~ining about 15 cells per 30 linear inch (i.e., 60 cells per 100 mm) was interpenetrated with a llli~Ule of 67 grams of chloromethyl styrene mon-)mer (CMS), 48.5 grams of styrene monomer, 5 grams of divinylben7sn~, 2.5 grams of tohl~n~ and 0.5 grams of azobisisobutyronitrile (AIBN) and then cured at 70~C for 24 hours in a nitrogen atmosphere.
The resultant interpenetrated resin was then further reacted by soaking for S 12 hours at 55~C in a mixture of l:S by volume of pyridine:acetone.
The foam treated as described above then was placed in a column and a gold cyanide solution cont~ining 40 percent of quartz to form a slurrywas pumpedupwards through it. A loading of 41,500 mg Au/kg foam onto this modified 10 polymer was obtained. The quartz particles slurry cont~ining the gold cyanide had the following particle size:
weight %
~ 150 micron 6.8 150-106 micron 57.8 106-75 micron 25.1 75-45 micron 9.2 < 45 micron 1.1 No loss in sorption capacity was observed following the ~ pi~g of the quartz slurry though ~hic chçmic~lly mn-1ifieci reticlll~tecl polyurethane foam for lS0 hours and no observable building of solid material was recorded.
A gold-con~ining ore (head grade 4.5 ppm) and concictin~ of quartz (29%), stilprom~l~ne (14%), chlorite (30%), calcite (5%), muscovite (4%), clolomite (3%), r pyrrhotite (10%), pyrite (2%) and minor minerals tO 100% was ground to give a P80 of 75 micron at a pulp density of 56% and treated with sodium cyanide in a 30 conventional carbon-in-leach plant using a direct injection of o~ygen. An analysis of the tailings water showed that it cont~in~d 104 ppm of free and WAD cyanide and 360 ppm thiocyanate. The tailings from this gold recovery circuit were passed over a 150 micron vibrated DSM screen to remove any ~ve~ e material and then allowed to flow under gravity through a column 30 cm diameter and two metres high cont~ining a 60 cell per 100 mm retic~ te~l polyurethane foam of density 28 kg/m3. No abrasion was observed after 21 days continll~l slurry flow.
EX~MPLE 2 To the tailings pulp described in Prelimin~ry Flr~mple 4 was added on a molar basis sufficient zinc to convert all free cyanide to the complex zinc cyanide 10 anion. This pulp cont~ining metal cyanides was then passed through retic~ ted and open-celled flexible polyurethane foams (cont~inin~ either 150 cells per 100 m~n or 60 cells per 100 mm) which had been chemicallymodified to cont~in a~pl~,xi..~t~ly 35% of a pyridine-based interpenetrated polymer. The chemical mo-lifi~ ~tinn wascon~ cted by interpenetrating under nitrogen the reti~-l~tecl polyurethane foam 15 with a solution cont~ining 100 parts vinylbenzyl chloride, 68 parts styrene, 7.5 parts divinyl benzene, 0.75 parts (AIBN) and 3.7 parts toluene. The interpenetrated polyurethane foam was cured by heating under nitrogen for 18 hours at 80 ~C in asealed vessel and then for a further period of 18 hours at 80 ~C in air. The polymer was then immersed for 12 hours at 50~C in a sohltion cont~ining pyridine 20 and 20 ~t~etone 100.
After a 2 mimlte contact with 2.3 g of this polymer in a 16 mm diameter tube (flowrate 47 ml/min.) the slurry exiting the column was analysed. 98% zinc,83% iron, 87% copper were found to have been removed giving a 95% recovery of 25 WAD cyanide. Once fully loaded with WAD cyanide the polymer was stripped using a 0.1 molar sulphuric acid soll~tion to generate HCN gas which was bubbledthrough a 1 molar solution of sodium hy~ide to form sodium cyanide.
An acid mine drainage slurry from a copper mine and co.~t~i..i..g 9.1%
quartz and 11 ppm of soluble copper was passed through the cr-ll-mn described in F~mple 2. The coll~mn cont~ine~l a 60 cell per-lOOmm retic~ tecl polyurethane foam which had been impregnated with di[2-ethylhexyl] phosphoric acid [D2EHPA].
After 1.5 minute contact time, 535'0 of the copper was removed from the slurry.
A slurry with a m~imllm particle size of 180 micron and cont~ining 11.9 ppm gold, 11.0 ppm copper, 13.2 ppm zinc, and 14.0 ppm ferric iron all as cyanides, and 0.3 g/l free cyanide at pH 11.0 was passed through the column as described in 10 Fx~mrle 2 at a flow rate of 90 ml/mimlte. The column was p~ck~ with a 15 cell/inch (60 cells/100 mm) reticulated polyurethane foam which had been impregnated with a gold-selective organic extractant (Aliquat 336 manufactured by Henkel Corp.). After a 1 mim-te contact time 63% of the gold cyanide, 1% of the copper cyanide, 26% of the zinc cyanide and 4% of the iron cyanide was recovered.
15 This example shows the selectivity which can be achieved accol-lhlg to the process of the present invention.
EXAMPLE S
A slurry cont~ining 10% of solid matter with an average particle size of 100 micron and cont~ining 5.92 ppm of chromillm(VI) at pH 2.2 was passed through thecolllmn as described in F~mple 2 with a flow rate of 90 ml/minllte The cQlllrnn was packed with a retic~ te~l and open-celled flexible polyurethane foam (60 cells per 100 mm) which had been rhrmic~lly modified to cQnt~in a~ .x;...~trly 35%
25 of a pyridine-based interpenetrated polymer. The chemical modi~ tion was con~ cted by interpenetrating under nitrogen the reticlll~te~l polyurethane foamwith a solution cont~ining 100 parts vinylbenzyl chloride, 68 parts styrene, 7.5 parts divinyl benzene, 0.75 parts azobisisobutyronitrile (AIBN) and 3.7 parts toluene.The interpenetrated polyurethane foam was cured by heating under nitrogen for 1830 hours at 80~C in a sealed vessel and then for a further period of 18 hours at 80~C
in air. The polymer was then immersed for 12 hours at 50~C in a sohltion cont~ining pyridine 20 and acetone 100.
After a minute contact time 79% of the chromium (VI) was removed. The column once fully loaded with chromium (VI), 91% of the chromi~lm was stripped using seven bed volumes of a solution cont~ining 0.5 molar sodium s~llph~te and 0.1 molar sodium hydroxide.
The slurry pumped to tailings normally contains cyanide, as "free" cyanide or WAD
(weak acid dissociable) cyanide, thiocyanates, etc. Thus, the tailings pondage contains anions which are toxic to h~lm~n, animal and bird life and therefore 10 represent a significant el,vilo~ e-nt~l hazard. The presence of these toxic anions maywell prevent the return of these sands underg~oulld as mine fill because of the potential for the toxic ions to enter the water table.
An example of the industrial application for this technology would be as an 15 alternative for the process as described by Coltrinari in PCT W 087/00072 or the well known AVR and Cyanisorb processes for the recovery of free and WAD
cyanide from the CIP or CIL slurry prior to its depositlon in a tailings dam. Inthese processes, the slurry is acidified to provide a sol~ltion pH generally between 5 and 8 in order to convert the cyanide species to HCN. Large volumes of low velocity air are then passed through the pH-adjusted tailings in a packed tower to volatilise the HCN. The HCN gas is readsorbed in an ~lk~lint- solution and returned to the CIP/CIL circuit. The stripped slurry must have its pH readjustedto 10 to 11 prior to deposition in the t~ilin~ dam. This process clearly suffers from a number of disadvantages: the requirement for twice adjusting the pH of the entire slurry and the use of very large volumes of air to vol~tili~e the HCN formed.
The application of a fixed bed of a suitable reticulated polyurethane foam for cyanide recovery offers a number of economic and kinetic advantages as will be described. In the presently described process, the free cyanide is COllv~lled to a 30 WAD cyanide such as by the tre~tm~nt of the slurry with a metal or soluble metal salt in particular with copper or zinc ~lllph~te The slurry then passes through a suitable bed of a selected reti~l~te~l polyurethane foam which has been modified - - -to contain a suitable ligand. The complex metal cyanide ion is rapidly adsorbed onto the polyurethane foam and the cyanide-depleted slurry passes to the tailings dam without the need for any pH adjustment (other than that which may be required by any particular mining or ellvi~ol"llental guvell~.llent regulation 5 applicable to that mine). The loaded polyurethane foam column is acidified to generate HCN gas which is adsorbed in an ~lk~line solution. A suitable courier gas such as nitrogen or air may be required. The acid solution may be reused for further stripping. Thus, a closed circuit plant can be ~lçcign~l in which much cm~ller volumes of air and sol-ltionc are required. Alternatively, if a ligand capable 10 of sorbing the WAD cyanide has been used and which is capable of being elutedat high pH, then the WAD cyanide can be stripped from the column. HCN gas can be generated from the strip solution and sodium cyanide formed or alternatively sodium cyanide reformed by electrolysis in a suitably ~ cignecl electrolysis cell.
A further application for the technology would be for the removal of soluble salts in lignite and other coals or for the removal of dissolved metal salts from soils in soil remediation processes, again, by allowing the slurry cont~inins~ the metal ions to flow through a fixed bed of retic~ te~l polyurethane foam having ion ~y~h~ngesites to sorb the metal ions.
Throughout this spe~ific~ti-ln and the claims which follow, unless the context requires otherwise, the word "colll~lise", or variations such as "comprises" or "comprising", will be understood to imply the incl~lcion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.
The following ~Y~mples are given to describe typical potential applications of this new technology. All percentages are by weight except where otherwise shown.
_ g _ A slurry was prepared by distributing 40 parts by weight of ground quartz particles in 100 parts of water. 80% of the quartz particles were between 100 S micron and 150 micron in size, the re-m~in~ler lay between 45 micron and 100 micron in size. This slurry was pumped both dowl,w~s and also u~w~ds through a 1.2 metre high block of reti~ll~ted polyurethane foam at particle flow rates in excess of 1 cm per second with negligible pressure drop across the bed.
A slurry was prepared by distributing 40 parts by weight of a clay mineral in 100 parts of water. 80% of the clay particles passed through a 75 micron sieve.
The slurry was pumped u~w~ds through a 1.2 metre high block of reticnl~tecl 15 polyurethane foam at particle flow rates of up to 1 cm per second. Air was introduced into the base of the foam bed and rapidly travelled through it in a vertical direction without s~lhst~nti~l pressure drop.
PRELIMII'I~RY EXAMPLE 3 Brown coal was mixed with water in a high shear mixer to disperse the fibrous coal particles and to form a slurry cont~ining 30% solids. This slurry was pumped u~w;llds through a 1.2 metre high block of reti~ll~ted polyurethane foam cont~ining about 15 cells per linear inch (i.e., 60 cells per 100 mm) at particle flow 25 rates of up to 1 cm per second.
48.4 grams of a retiç~ ted polyurethane foam cont~ining about 15 cells per 30 linear inch (i.e., 60 cells per 100 mm) was interpenetrated with a llli~Ule of 67 grams of chloromethyl styrene mon-)mer (CMS), 48.5 grams of styrene monomer, 5 grams of divinylben7sn~, 2.5 grams of tohl~n~ and 0.5 grams of azobisisobutyronitrile (AIBN) and then cured at 70~C for 24 hours in a nitrogen atmosphere.
The resultant interpenetrated resin was then further reacted by soaking for S 12 hours at 55~C in a mixture of l:S by volume of pyridine:acetone.
The foam treated as described above then was placed in a column and a gold cyanide solution cont~ining 40 percent of quartz to form a slurrywas pumpedupwards through it. A loading of 41,500 mg Au/kg foam onto this modified 10 polymer was obtained. The quartz particles slurry cont~ining the gold cyanide had the following particle size:
weight %
~ 150 micron 6.8 150-106 micron 57.8 106-75 micron 25.1 75-45 micron 9.2 < 45 micron 1.1 No loss in sorption capacity was observed following the ~ pi~g of the quartz slurry though ~hic chçmic~lly mn-1ifieci reticlll~tecl polyurethane foam for lS0 hours and no observable building of solid material was recorded.
A gold-con~ining ore (head grade 4.5 ppm) and concictin~ of quartz (29%), stilprom~l~ne (14%), chlorite (30%), calcite (5%), muscovite (4%), clolomite (3%), r pyrrhotite (10%), pyrite (2%) and minor minerals tO 100% was ground to give a P80 of 75 micron at a pulp density of 56% and treated with sodium cyanide in a 30 conventional carbon-in-leach plant using a direct injection of o~ygen. An analysis of the tailings water showed that it cont~in~d 104 ppm of free and WAD cyanide and 360 ppm thiocyanate. The tailings from this gold recovery circuit were passed over a 150 micron vibrated DSM screen to remove any ~ve~ e material and then allowed to flow under gravity through a column 30 cm diameter and two metres high cont~ining a 60 cell per 100 mm retic~ te~l polyurethane foam of density 28 kg/m3. No abrasion was observed after 21 days continll~l slurry flow.
EX~MPLE 2 To the tailings pulp described in Prelimin~ry Flr~mple 4 was added on a molar basis sufficient zinc to convert all free cyanide to the complex zinc cyanide 10 anion. This pulp cont~ining metal cyanides was then passed through retic~ ted and open-celled flexible polyurethane foams (cont~inin~ either 150 cells per 100 m~n or 60 cells per 100 mm) which had been chemicallymodified to cont~in a~pl~,xi..~t~ly 35% of a pyridine-based interpenetrated polymer. The chemical mo-lifi~ ~tinn wascon~ cted by interpenetrating under nitrogen the reti~-l~tecl polyurethane foam 15 with a solution cont~ining 100 parts vinylbenzyl chloride, 68 parts styrene, 7.5 parts divinyl benzene, 0.75 parts (AIBN) and 3.7 parts toluene. The interpenetrated polyurethane foam was cured by heating under nitrogen for 18 hours at 80 ~C in asealed vessel and then for a further period of 18 hours at 80 ~C in air. The polymer was then immersed for 12 hours at 50~C in a sohltion cont~ining pyridine 20 and 20 ~t~etone 100.
After a 2 mimlte contact with 2.3 g of this polymer in a 16 mm diameter tube (flowrate 47 ml/min.) the slurry exiting the column was analysed. 98% zinc,83% iron, 87% copper were found to have been removed giving a 95% recovery of 25 WAD cyanide. Once fully loaded with WAD cyanide the polymer was stripped using a 0.1 molar sulphuric acid soll~tion to generate HCN gas which was bubbledthrough a 1 molar solution of sodium hy~ide to form sodium cyanide.
An acid mine drainage slurry from a copper mine and co.~t~i..i..g 9.1%
quartz and 11 ppm of soluble copper was passed through the cr-ll-mn described in F~mple 2. The coll~mn cont~ine~l a 60 cell per-lOOmm retic~ tecl polyurethane foam which had been impregnated with di[2-ethylhexyl] phosphoric acid [D2EHPA].
After 1.5 minute contact time, 535'0 of the copper was removed from the slurry.
A slurry with a m~imllm particle size of 180 micron and cont~ining 11.9 ppm gold, 11.0 ppm copper, 13.2 ppm zinc, and 14.0 ppm ferric iron all as cyanides, and 0.3 g/l free cyanide at pH 11.0 was passed through the column as described in 10 Fx~mrle 2 at a flow rate of 90 ml/mimlte. The column was p~ck~ with a 15 cell/inch (60 cells/100 mm) reticulated polyurethane foam which had been impregnated with a gold-selective organic extractant (Aliquat 336 manufactured by Henkel Corp.). After a 1 mim-te contact time 63% of the gold cyanide, 1% of the copper cyanide, 26% of the zinc cyanide and 4% of the iron cyanide was recovered.
15 This example shows the selectivity which can be achieved accol-lhlg to the process of the present invention.
EXAMPLE S
A slurry cont~ining 10% of solid matter with an average particle size of 100 micron and cont~ining 5.92 ppm of chromillm(VI) at pH 2.2 was passed through thecolllmn as described in F~mple 2 with a flow rate of 90 ml/minllte The cQlllrnn was packed with a retic~ te~l and open-celled flexible polyurethane foam (60 cells per 100 mm) which had been rhrmic~lly modified to cQnt~in a~ .x;...~trly 35%
25 of a pyridine-based interpenetrated polymer. The chemical modi~ tion was con~ cted by interpenetrating under nitrogen the reticlll~te~l polyurethane foamwith a solution cont~ining 100 parts vinylbenzyl chloride, 68 parts styrene, 7.5 parts divinyl benzene, 0.75 parts azobisisobutyronitrile (AIBN) and 3.7 parts toluene.The interpenetrated polyurethane foam was cured by heating under nitrogen for 1830 hours at 80~C in a sealed vessel and then for a further period of 18 hours at 80~C
in air. The polymer was then immersed for 12 hours at 50~C in a sohltion cont~ining pyridine 20 and acetone 100.
After a minute contact time 79% of the chromium (VI) was removed. The column once fully loaded with chromium (VI), 91% of the chromi~lm was stripped using seven bed volumes of a solution cont~ining 0.5 molar sodium s~llph~te and 0.1 molar sodium hydroxide.
Claims (23)
1. A process for the selective removal of ions from a solution having solid materials dispersed therein comprising passing the solution having solid materials dispersed therein through a bed of coarse open cell polymeric foam having ion exchange sites.
2. A process according to claim 1 wherein the coarse open cell polymeric foam is a coarse cell polyurethane foam.
3. A process according to claim 2 wherein the coarse open cell polymeric foam is a coarse cell reticulated polyurethane foam.
4. A process according to any one of claims 1 to 3 wherein the polyurethane foam is either polyester based or polyether based.
5. A process according to any one of claims 1 to 4 wherein the polyurethane foam is polyether based.
6. A process according to any one of claims 1 to 5 wherein the cell size of the polymeric foam is greater than 45 cells per linear inch (180 cells per 100mm).
7. A process according to any one of claims 1 to 6 wherein the cell size of the polymeric foam is in the range of from 45 cells per linear inch (180 cells per 100mm) to less than 15 cells per linear inch (60 cells per 100mm).
8. A process according to any one of claims 1 to 7 wherein the coarse open cell polymeric foam is in the form of a fixed bed in a reaction vessel.
9. A process according to any one of claims 1 to 8 wherein the coarse open cell polymeric foam is flexible and able to undergo repeated flexing.
10. A process according to any one of claims 1 to 9 wherein the ion exchange sites of the coarse open cell polymeric foam are suitable for the selective sorption of heavy metals including arsenic, cadmium, chromium, iron, zinc and mercury, precious metals including gold, silver, platinum, palladium, rhodium, iridium, ruthenium and osmium; other anions and cations including halides, sulfates, nitrates, cyanides, thiocyanates, cyanogen, carbonates and phosphates.
11. A process for the extraction of metal values from mineral deposits accordingto any one of claims 1 to 9 wherein the solution comprises metal ions.
12. A process for the removal of soluble salts in lignite and other coals according to any one of claims 1 to 9 wherein the solution comprises soluble salts of lignite and other coals.
13. A process for the remediation of soil according to any one of claims 1 to 9 wherein the solution is formed by mixing the soil into an aqueous media.
14. An ion-selective coarse open cell polymeric foam in which the cell size is sufficient to allow solutions having solids dispersed therein to pass through said foam.
15. A polymeric foam according to claim 14 wherein the coarse open cell polymeric foam is a coarse cell polyurethane foam.
16. A polymeric foam according to claim 14 wherein the coarse open cell polymeric foam is a coarse cell reticulated polyurethane foam.
17. A polymeric foam according to any one of claims 14 to 16 wherein the polyurethane foam is either polyester based or polyether based.
18. A polymeric foam according to any one of claims 14 to 17 wherein the polyurethane foam is polyether based.
19. A polymeric foam according to any one of claims 14 to 18 wherein the cell size of the polymeric foam is greater than 45 cells per linear inch (180 cells per 100mm).
20. A polymeric foam according to any one of claims 14 to 19 wherein the cell size of the polymeric foam is in the range of from 45 cells per linear inch (180 cells per 100mm) to less than 15 cells per linear inch (60 cells per 100mm).
21. A polymeric foam according to any one of claims 14 to 20 wherein the coarse open cell polymeric foam is in the form of a fixed bed in a reaction vessel.
22. A polymeric foam according to any one of claims 14 to 21 wherein the coarse open cell polymeric foam is flexible and able to undergo repeated flexing.
23. A polymeric foam according to any one of claims 14 to 22 wherein the ion exchange sites of the coarse open cell polymeric foam are suitable for the selective sorption of heavy metals including arsenic, cadmium, chromium, iron, zinc and mercury, precious metals including gold, silver, platinum, palladium, rhodium, iridium, ruthenium and osmium; other anions and cations including halides, sulfates, nitrates, cyanides, thiocyanates, cyanogen, carbonates and phosphates.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AUPN4830/95 | 1995-03-10 | ||
| AUPN483095 | 1995-03-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2217866A1 true CA2217866A1 (en) | 1996-09-19 |
Family
ID=3789161
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002217866A Abandoned CA2217866A1 (en) | 1995-03-10 | 1996-03-12 | Polymer sorbent for ion recovery processes |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0814907A4 (en) |
| CA (1) | CA2217866A1 (en) |
| NZ (1) | NZ302613A (en) |
| WO (1) | WO1996028251A1 (en) |
| ZA (1) | ZA961914B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AUPO900097A0 (en) * | 1997-09-05 | 1997-10-02 | Arton (No 001) Pty Ltd | Process |
| AU749790B2 (en) * | 1997-09-25 | 2002-07-04 | Oretek Ltd | Ion exchange |
| AUPO946297A0 (en) | 1997-09-25 | 1997-10-16 | Holbray Pty Ltd | Ion exchange |
| WO2004078342A1 (en) | 2003-03-04 | 2004-09-16 | Manac Inc. | Scavenger for substance having anionic substituent |
| WO2016202767A1 (en) * | 2015-06-19 | 2016-12-22 | Basf Se | Polyurethane composite for neutralization of an acid mine drainage (amd) |
| GB202010885D0 (en) * | 2020-07-15 | 2020-08-26 | Johnson Matthey Plc | Methods for the separation and/or purification of metals |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2820732A1 (en) * | 1978-05-12 | 1979-11-22 | Basf Ag | CHELATING AGENTS AND / OR CHELATE COMPLEXES CONTAINING OPEN-CELL POLYURETHANE FOAMS |
| FR2488264A1 (en) * | 1980-08-05 | 1982-02-12 | Le I Textilnoi | Open-cell polyvinyl formal or polyurethane foam - contg. ion exchange or complex forming fibres, has high exchange rates, osmotic stability, mechanical strength and elastic properties |
| CA2138760A1 (en) * | 1992-06-25 | 1994-01-06 | Frank Lawson | Ion exchange resin |
| AU629790B3 (en) * | 1992-06-29 | 1992-10-08 | William Harold Jay | An electrochemical process employing a modified polymeric foam to enhance the recoverability of metal values from solution |
-
1996
- 1996-03-08 ZA ZA961914A patent/ZA961914B/en unknown
- 1996-03-12 WO PCT/AU1996/000133 patent/WO1996028251A1/en not_active Application Discontinuation
- 1996-03-12 EP EP96904667A patent/EP0814907A4/en not_active Withdrawn
- 1996-03-12 NZ NZ302613A patent/NZ302613A/en unknown
- 1996-03-12 CA CA002217866A patent/CA2217866A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| EP0814907A1 (en) | 1998-01-07 |
| WO1996028251A1 (en) | 1996-09-19 |
| EP0814907A4 (en) | 1999-05-19 |
| NZ302613A (en) | 2000-01-28 |
| ZA961914B (en) | 1996-09-12 |
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