Ion Exchange Technology
Ion exchange processes have found a valuable place in the treatment of metal wastes from plating, metal working, mining and other industrial processes where there is a discharge of toxic metals, also ion exchange is a convenient way to concentrate and achieve precious metal recovery.
Ion exchange is usually employed with two columns, one acting as a worker and the second as a polisher, this configuration allows for full loading on the worker column without compromising leakage to final discharge. Ion exchange columns are regenerated when exhausted with acid (sulphuric, hydrochloric, etc.) The amounts will depend on the composition of the feed water and cycle control will be based on treated water quality. The spent regenerants can be sent for electro-winning, evaporation concentration, or batch treatment.
Belmar has developed ion exchange processes which allow the separation of metal ions from the feed water for further processing, applying knowledge of specific ion exchange resins and their typical affinities for metals at different pH values. Belmar’s ion exchange technology offers a number of significant advantages over conventional ion exchange systems.
Selective Metal Recovery
Main system components include:
- Fully automatic- minimum labour involved.
- Modular design, factory skid mounted, pre-wired – for ease of installation.
- Process simplification – wide range of metal concentrations.
- Flexibility in processing variable feed.
- Value added – High purity product.
- Modular expansion – The plant is modular and can easily be expanded and reconfigured.
- Designed to be compatible with your existing waste management system.
Our team is staffed by qualified engineers and chemists and with extensive experience in METAL FINISHING, processing and electroplating industries. In this regard we are ideally placed to provide process consulting and design and supply of ion exchange equipment to all regions of the world.
Selective Metal Ion Exchange with Electrowinning Technology
Ion Exchange Application Testing
The purpose of these test programs is to establish “proof of concept” and to determine the optimum conditions under which ion exchange can perform the process aim in combination with an optimized leach process. Typically a full ion exchange test program will analyse process aim in conjunction with solution data specified supplied by the client. A test program will then be developed and agreed with the client.
The over-riding aim of the program will be to provide definitive information on the performance characteristics and potential windows of operation for the Belmar ion exchange technology in this application, to a level where it is possible to make a realistic judgment as to the potential economics of an operating plant.
Metal Selective Ion Exchange Resins
A number of Ion Exchange Resins have been synthesized where a ligand is bound on the polymer matrix of a resin by a covalent bond. Resins with Bi or polydentate ligands are also called chelating resins. The following are examples of chelating resins used in the chemical industry.
By forming complexes with metal cations in solution this type of resin shows a very high selectivity for complex forming metals over elements that do not. For example these resins can remove traces of metal cations such as Cu2+ from solutions of 30% NaCl where conventional strong cation resin would not work.
For Antimony and Bismuth removal from copper sulphate electrolytes Belmar uses Lanxess TP260 resin based on amino methyl phosphonic functional group. Belmar has a commercialised system complete HCL recovery to achieve an economical solution for copper refineries.
Specialist Ion Exchange Resins
Belmar also works with other chelating resins such as hydroxypropyl picolylamine functional groups (HPPA) which have a strong affinity even at low pH for transition metals and can be used even in the presence of strong complexing agents such as EDTA.
Bis-picolylamine resin (BPA) is useful for cobalt solution purification where Nickel can be recovered even at low pH. Another application for BPA resins is the purification of trivalent chrome baths by removing Ferric, Copper and Zinc impurities.
Applications
- Rinse Water Recycling - Metal Finishing
- Aluminium Removal - Tartaric Sulphuric Anodising
- Copper - Nickel- Cobalt Recovery
- Selective Metal Recovery