Crosslinking is the process of joining individual polymer chains together. The aim is to reduce the uranium concentration below 20 g the lead columns contain 100. Us8936770b2 hydrometallurgical process and method for. Ion exchange investigation for recovery of uranium from acidic pregnant leach solutions. In addition to waste water treatment they are also useful for extraction of various metals such as gold, uranium and copper. Based on the current understanding of uranium deposits in the commonwealth of virginia, extraction of uranium ore would use openpit mining, or underground mining, or a combination of both.
Ion exchange the bestknown metallurgical application of ion exchange is in the recovery of uranium a south africandeveloped process in which mintek, with its nimcix fluidisedbed contactor, played a major role. Part 2 covers the recovery of uranium from acidic or alkaline leach liquors. Mining waste treatment technology selectiontechnology. Electrodialysis with ionexchange membranes is important in chemistry, chemical technology and hydrometallurgy as a basic operation which eliminates the usual chemical neutralization and makes it possible to remove excess acidity and alkalinity, to separate mixtures of elements whose properties are similar and to extract radioactive products from waste waters. Ion exchange also plays a valuable role in the management of nuclear wastes generated in the fuel cycle. The macroporous resins gave inferior loading, in the range of 40 50.
Hno3 to remove any residual uranium that might still have been present on the resin. The animation of ion exchange at the resin level shows the undesired ions from the liquid feed, in green, being exchanged for ions of the same charge, in blue, within the resin. The strongly acidic resins have sulfonic acid functionality while. The use ion exchange resins throughout the lifecycle of a. Ion exchange is an exchange of ions between two electrolytes or between an electrolyte solution and a complex. Pdf one of the main issues associated with the application of. Ion exchange resins for the most part, the resin backbones used today consist of styrene or acrylic polymers crosslinked with divinylbenzene resins with cationexchange functionality are available as either strongly acidic or weakly acidic ion exchangers. Pdf selection of optimum ion exchange process for uranium extraction find, read. The resin containing glycol amic acid groups shows the possibility to recover scandium from chloride aqueous solutions. The metals are then recovered by various specialty regeneration techniques or by incinerating the resin.
Filled with illustrations and tables, this work covers the flow of source material from the mined or concentrate state to the finished product. Solvent extraction and ion exchange applications in africas resurging uranium industry. Part i discusses the fundamentals of ion exchange, the structure, propertries and the main processes using ion exchange resins. The rock is dissolved in acid and added to an anionexchange column that is pretreated with 9. Systems for purifying small gas streams are already in use in clean rooms. The uranium as it is passed through the column is present as a uiv coordination compound with a ligand at different valent states and is followed by an. Ion exchange is widely used in chemical and mining processes for separating one metal from another and for impurity removal. It also highlights ion exchange, carbon adsorption and solvent extraction processes for solution purification and concentration. Electrodialysis with ion exchange membranes is important in chemistry, chemical technology and hydrometallurgy as a basic operation which eliminates the usual chemical neutralization and makes it possible to remove excess acidity and alkalinity, to separate mixtures of elements whose properties are similar and to extract radioactive products from waste waters. Finally, the yellowcake is packed in 55gallon drums to be transported to a uranium conversion facility, where it is processed through the stages of the nuclear fuel cycle to produce fuel for use in. Notes of practical application of ion exchange resins in uranium. Ion exchange resins are important components in a variety of mining applications.
Evaluating ion exchange resin efficiency and oxidative. Sorption of uranium, titanium and iron chlorocomplexes on anionic exchange resins 2 sustinere publica. At ph 1, the adsorption selectivity of scandium can be obtained among the others metals. The uranium stripped with hno3 was used to calculate the residual uranium concentrations on the resin. Resintech makes a variety of ion exchange products that are used for precious metal recovery and for solution mining. Uranium remediation by ion exchange and sorption methods. Towards the application of weak base and chelation ion exchange. Uranium pcil 2781 30 well depth 575625 ft 700950 ft. Ion exchange takes place in one column, while the resin in the second column is being regenerated, resulting in continuous operation. Common practice is to combine the leach residue with the barren raffinates. Ion exchange resins are commonly used to remove trace levels and to concentrate precious metals.
Stucker v, ranville k, newmann m, peacock a, cho j, hatfield k. The eggins type con tinuous ion exchange contactor has been operated with the anion ex change system for about two years, and there is now development work in progress on other types of. This group is lead by a world renowned hydrometallurgist with extensive operating experience in projects spanning the globe. Resintech makes a variety of ion exchange products that are used for. Hydrometallurgy uranium omc has fostered a highly skilled team specialising in the field of hydrometallurgy. Selective ion exchange recovery of rare earth elements.
One such technology entering or reentering the hydrometallurgy industry is the resininpulp process. Use add reply to replyparticipate in a topicdiscussion most frequent. S6328 a resins and silver impregnated activated carbon to examine uranium sorption and extraction for each material. Using add reply allows you to attach images or pdf files and provide a more complete input. A comparative study of rare earth, ferric and aluminum ions ion exchange behavior on gel sulfonated olystyrene cation exchange resins depending on the degree of the matrix crosslinking and ph of the solution is presented. The loading capacity of u 3o 8 was about 70 gl of wet settled resin w. Next, the resins were soaked in dd water for 2 hours to ensure proper hydration. Selected ion exchange applications in the hydrometallurgical. Ion exchanger ionexchange resin beads ionexchange column used for protein purification. This paper gives a comprehensive overview of the chemical and physical requirements that need to be accommodated by ix resins in the various applications. They found that currently available anionexchange resins with apparently identical physical properties had significantly different recoveries for hexavalent uranium at.
Eluant solution used to strip the loaded uranium from the resin. Ion exchange, in situ uranium recovery, restauration, acid and carbonate leaching. Ion exchange systems of chelating ion exchange resins, bead and foam impregnates have been evaluated for the possible applications to copper winning processes. Uranium has been recovered via ion exchange resins since the 1950s. Removing radioactive contamination from ion exchange resins. Q pw ion exchange for recovery of precious metals by w. Ion exchange is used in nearly every part of the nuclear fuel cycle from the purification of uranium from its ore to the final recovery of uranium and transmutation products.
Nuclear regulatory commission nrc has licensed numerous uranium recovery facilities in the united states, which used a variety of extraction methods. Application of an ion exchange loading correlation for nickel. Sorption of uranium, titanium and iron chlorocomplexes on. In addition to conventional uranium milling and in situ recovery isr, which are currently used to extract uranium from ore, some nrclicensed facilities used extraction methods. Taylor ix plant is designed to treat 10,000 gpm of mine water for removal of uranium. This article belongs to the special issue advances in hydrometallurgy. Evaluation of various durability tests to assess resin for in.
The amine has the ability to give up anions in exchange for anions in solution, in this case, uranium. Notes of practical application of ion exchange resins in. Protea mining chemicals is the distributor of lanxess ion exchange resins for applications in the mining industry. The extensive reference listover 850makes this set a. Usage examples continuous ion exchangers are used when it is imperative that product be continually generated. Ion exchange resins for the mining industry jacobi resinex. Selective ion exchange of rees is possible at the ph range of 1. Ion exchange resins for uranium extraction from sulfate based mining process. Hydrometallurgical process and method for recovering metals download pdf. The uranium is separated from the leach solutions by solventextraction or ionexchange. A method of simultaneously obtaining separate enriched fractions of 235 u and 238 u from isotopic mixtures thereof with the use of an ion exchange column by passing a liquid body containing the isotopic mixture through the column. Power plants energized by ion exchange resins for water.
The ion exchange process for recovering uranium from mine water utilizes a quaternary amine incorporated onto a porous styrene divinylbenzene bead. Silica fouling of strongbase ion exchange resins used for uranium recovery. Evaluation and application of anion exchange resins to measure groundwater uranium flux at a former uranium mill site. Selective ion exchange recovery of rare earth elements from. In a recent amec minproc study it was concluded that the hydrometallurgical flowsheet capital cost. The rock is dissolved in acid and added to an anionexchange column that is pretreated with 9 moll. Such deposits are not removed by common treatment and require special care. Evaluation and application of anion exchange resins to. Recoveries from all ion exchange resins were in the range of 94e99% for aqueous uranium in the environmentally relevant. The dowex resins had the highest uranium sorption, followed by lewatit, purolite and the activated carbon. This twovolume set provides a full account of hydrometallurgy. Ract information is presented on the process chemistry of plutonium in both cation and anion exchange systems. These general terms incorporate a large variety of design possibilitiesthere are as many methods of mining uranium as there are orebody sizes, shapes, and mineral constituents.
Common examples are vanadate, molybdate, chloride, and nitrate. Since the introduction of insitu uranium recovery techniques, ion exchange ix resins have become an integral part of the flowsheet in many mines around the globe. The chelating resins having aminophosphonic, iminodiacetate, thiol and thiouronium functional groups are used for removing specific ions from a mixture of ions. Resinex is ready with a full assortment of resins for mining applications. The ion exchange configuration is shown in figure 8. Other tests of ion exchange with mining influenced waters are referenced in gusek and figueroa 2009. Rare earth metal ions replace the sodium ions on the ion exchange resin.
Hydrometallurgy is concerned with the selective leaching of metallic compounds to form a solution from which the metals hydrometallurgy originated in the 16th century, but its principal development took place in the 20th century, stimulated partly by the desire to extract gold from lowgrade ores. Some aspects of ion exchange in copper hydrometallurgy. A regeneratlon process invoivlng eiectrolysls of an eluate is descrlbed for silver. These products include the thiol and thiol uranium functional resins, as well as the more conventional strong acid and strong base resins and granular activated carbon. The use ion exchange resins throughout the lifecycle of a mine. Metals free fulltext selective extraction of rare earth elements. Examples of ion exchange processes developed at hazen include the recovery of gold and silver from cyanide solutions and alternate lixiviants, and uranium recovery from both acid and carbonate circuits. Recovery of scandium from chloride media using the novel. Pdf solvent extraction and ion exchange applications in. Uranium adsorption on ionexchange resins batch testing. Continuous simulated moving bed smb type ion exchange processes are usually operated in crosscurrent mode for metal separations whereas countercurrent mode is commonly used for fine chemicals. Research in the field of uranium, base metals and noble metals hydrometallurgy.
Mixed bed ion exchangers have resins for both cation and anion exchange within the same column. Recovery of scandium from chloride media using the novel ion. A wide variety of process streams benefit from the application of ion exchange resins, as shown in table 1. The geltype resins showed more uranium loading over the macroporous resins. Jfalsrslkyafgmuhfffaoysan uranium0 chemical compound. Abstractthis study focused on separation and recovery of scandium from chloride solution using the new synthesized ion exchange resin. A very important case of ion exchange is the purex process plutonium uranium extraction process, which is used to separate the plutonium239 and the uranium from americium, curium, neptunium, the radioactive fission products that come from nuclear reactors. The use of both process types was investigated for hydrometallurgical purification of agnacl solution from divalent impurity metals ca, mg, pb, zn. Advances in hydrometallurgy, advances in joining of automotive alloys. Uranium removal from contaminated groundwater by synthetic resins. Uranium carbonate industrial waste streams from a brazilian nuclear production plant were treated by an ion exchange process using a type ii strong base anion exchange resin, ira910a with a dimethyl 2hydroxy ethyl functional group.
The stream needed to be boiled for 6 h to lower the total carbonate concentration before it could be treated. The use of ionexchange membranes in the hydrometallurgy. The ion exchange system extracts and concentrates the uranium to produce a material, which is called yellowcake because of its yellowish color. In most cases the term is used to denote the processes of purification, separation, and decontamination of aqueous and other ioncontaining solutions with solid polymeric or mineralic ion. Removing radioactive contamination from ion exchange.
In hydrometallurgical applications, ion exchange resins have been used increasingly for the recovery and purification ofmetal pregnant solutions or for effluent treatment. Ion exchange offers various grades of chelating resins, strong and weak acid cation exchange resins for removing or recovering metal ions. Lewatit ion exchange resins all around solutions for. The water then proceeds to the uranium ion exchange section. Advantages advantages of ion exchange include the following. Lewatit can be used to bind and immobilize heavy metal contaminants in the soil. However, solidphase extraction based on chelating ion exchange resins. The use of ionexchange membranes in the hydrometallurgy of. In the cation exchange system plutonium is sorbed from a 0. Removal of uranium from mine water using ion exchange at.
Table 1 applications of ion exchange in hydrometallurgy origin of stream to be treated ion exchange application ore, after heap or agitated leach primary recovery of metals of interest, e. The ion exchange processes are carried out in both fged beds and continuous column equipment. The uranium industry was the first hydrometallurgical industry to make extensive use of these two unit operations. Hydrometallurgy ion exchange offers various grades of chelating resins, strong and weak acid cation exchange resins for removing or recovering metal ions. New ion exchange resin for uranium recovery industrial. Ion exchange resins for uranium adsorption are strong base quaternary. These products have application in a number of hydrometallurgical process including.
At the schwartzwalder mine in colorado, resins were used to recover uranium from mining and metallurgical processes zielinski et al. Acidic ion exchange resins adsorb alkali gases such as nh 3, while alkali ion exchange resins adsorb acidic gases, such as hcl and so 2. Nuclear fuel cycle extractingg uranium from its ores. Fundamentals of radium and uranium removal from drinking.