TAMI (IMI) Central R&D Inst.
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Ion Exchange Separation

Ion Exchange Separation

Ion exchange is a powerful technology which was found to have multiple applications over the years and is successfully used in many fields, to name a few:

  • Water treatment - softening, demineralization, groundwater remediation and potable water production, brine purification, wastewater treatment, etc.
  • Metallurgy - heavy (trace) metal removal and precious metal recovery from hydrometallurgical streams, uranium and gold recovery, etc.
  • Food industry – softening and demineralization of sugar juices and whey, color removal from syrups, glucose treatment, citric acid purification, etc.
  • Chemical and pharmaceutical industries- hydrogen peroxide purification, chlorine production, extraction of antibiotics, taste-masking, purification of organic acids, etc.
  • Electronics - electronic waste treatment, etching solutions purification, etc.
  • Chromatography – separation of monosaccharides, separation of isomers, etc.

In many cases, ion exchange substitutes other separation and purification technologies due to its many advantages. While processes like solvent extraction involve significant capital and operating costs, occupy a large footprint area and require significant quantities of water and flammable extractants which can cause serious environmental and safety problems, the ion exchange process offers lower environmental burden and economic constrains and higher selectivity and separation capabilities of target products. In addition, the ion exchange is regularly able to provide more effective and direct purification compared to purification by precipitation, or solvent extraction.

The principle of the ion exchange process is the trading of different ions or complexes on a resin/sorbent bed, triggered by the different affinity (selectivity) of the resin to each one of the ions. A typical resin is a water insoluble polymer cross-linked matrix with a functional group. The exchanging ions from the treated solution are bonded (chemically absorbed) to the resin's functional group sites which may vary in types. The typical types are strong/weak acid cations (SAC/WAC) responsible for collecting cations and strong/weak basic anions responsible for collecting anions. The bonding can be of an ionic, or a covalent (ligand) type, in the case of chelating resins. For some applications mineral type adsorbents (such as zeolites) are used to physically adsorb ions in a molecular sieve (ion-sieve) mechanism.

TAMI has vast practical experience and expertise in the ion exchange field.
We have the ability to study and develop separation processes, both in batch and continuous operation. We have experience in finding the appropriate ion exchanger (resin), identification of selectivity indexes, determination of resin capacity and prediction of expected results in static or continuous processes. We have the possibility to scale up the ion exchange process from an idea, through small laboratory columns and up to a pilot system and provide the whole package required for the design of a full-scale plant. We have proven methodology for testing, simulating and scaling up batch and continuous (CIX) processes using static columns or continues pilot system (IXSEP) in which all the essential design parameters (efficiency, productivity, concentrations, etc.) are offered to the client.


Our capabilities include:

  • Design of a conceptual block diagram for separation/purification processes, based on ion exchange – realizing our customer's idea.
  • Choosing the most suitable resins for a specific process: using our company's access to the most comprehensive and extensive databases of chemical literature and our vast experience.
  • Testing the feasibility of the process in the lab:
    - Performing beaker tests to compare between selected resins.
    - Determining important parameters, such as: process kinetics, resins work capacity, selectivity to target ions, etc.
    - Testing the most qualified resins in small columns (up to 1'' and 300 ml).

  • Scaling-up the process to a pilot scale:
    - In case of a batch process – testing in a column of up to 6'' and 35 liters.
    - In case of continuous process – testing in a IXSEP merry-go-round system consisting of up to 24 columns.

  • Delivering all the technical data required for a design for a full-scale plant:
    - Productivity, efficiency, and capacity.
    - Raw material consumption, product and by-product compositions and water usage.
    - Operating conditions - flow rates, system configuration, cycle time.