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Solid/Liquid Separation FAQs

Solid/liquid separation solutions from Multotec are used in chemical and mineral processing, coal and water treatment plants. More than 40 years’ experience in solid/liquid separation in the mineral processing industry and teams of skilled engineers with detailed process flow sheet expertise, has positioned Multotec as a leader in solid/liquid separation processes used for mineral processing. As a result, Multotec now designs, manufactures, supplies and installs world-leading solid/liquid separation solutions that increase a plant’s rate of separation, thereby contributing to increased process efficiency.

In addition, the on-hand expertise within the company structure allows Multotec’s equipment to be seamlessly integrated into both new and existing applications, which helps lower clients’ overall cost per ton. All solid/liquid separation solutions are manufactured according to ISO 9001 standards.


Water Treatment FAQs

Multotec has partnered with Australian-based Clean TeQ to provide CIF® for process water treatment and Clean-iX® for metals recovery in water. CIF® is a continuous counter-current ion exchange technology and Clean-iX® is built on the foundations of continuous ion exchange technology.


What is the difference between solvent extraction and ion exchange?
Ion exchange is the exchange of ions of the same charge between an insoluble solid (the resin) and a solution in contact with it.
Solvent extraction is a method used to separate compounds based on their relative solubilities in two different immiscible liquids, mostly water and an organic solvent.
Ion exchange is typically used for recovery of far lower concentration target elements (less than 1 g/L in solution) whereas solvent extraction is used to recover elements in concentrations greater than 1 g/L.
Can ion exchange be used for seawater desalination?
Due to the very high concentration of sodium and chloride ions (some 30g/L)  in seawater and the reduced affinity of ion exchange resins for monovalent elements such as sodium and chloride, ion exchange cannot effectively and economically be used for seawater desalination.
Can the DeSAlx® technology produce potable water?
Yes, depending on the quality of the feed water, the DeSAlx® technology can produce potable water. In some cases, reverse osmosis is needed on the back end of DeSAlx® to produce potable water.
What is the limit of suspended solids (TSS) that the DeSAlx® or CIF® technology can handle?
In a water treatment application,  the limit of total suspended solids (expressed as TSS) feeding the DeSAlx®/CIF® continuous ion exchange technology must not be more than 100 mg/L.
Does the movement of the resin cause resin loss or breakage?
No, the patented DeSAlx®/CIF® process uses a proprietary air lift system for moving or transferring resin between stages, which causes limited attrition. Resin loss due to limited attrition amounts to a maximum of 10% (normally less) of the installed resin volume per year.
How long does resin last before it has be replaced?
Different types of resin have different lifetimes, varying anywhere between 5 to 10 years.
What are the best applications for the DeSAlx®/CIF® continuous ion exchange technology?
  • Zero-liquid discharge treatment of sulphate dominant water
  • Selective metals recovery from effluents (less than 800 mg/L)
  • Mine water (AMD) and process streams
  • Treatment of mine water in the presence of oils and grease
  • Pre-treatment to reverse osmosis (RO) for the removal of scaling elements and suspended solids
  • Treatment of secondary treated sewage effluent for total dissolved solids (TDS), ammonia and nitrate removal.
What advantages do DeSAlx®/CIF® technology have over other ion exchange technologies - i.e. batch?
Batch ion exchange is highly susceptible to blockages, cannot handle suspended solids and is less efficient in targeted element removal. Regeneration of batch ion exchange is also relatively inefficient and therefore recoveries are lower. High-quality chemicals are also required to ensure that scaling of resins do not occur, whereas DeSAlx® technology can use low-cost chemicals such as sulphuric acid and lime. The DeSAlx® can also handle variations in feed water quality whereas batch ion exchange is fairly limited in its ability to handle variations.
Why should I consider using ion exchange technology as a water treatment solution when membrane technology can do it?
In cases where the water is high in scaling elements (such as hardness e.g. Ca, Mg ions) or fouling elements (such as high dissolved organics) the membrane technology will be limited in the water recovery that it can deliver. Depending on the scaling elements, membrane technology can be limited to less than 60%.In these cases continuous ion exchange can be used as pre-treatment to remove the scaling and fouling elements, thereby enabling the membrane technology to operate at high recovery (greater than 80%) or used as a standalone treatment system (recovery exceeding 90%). Membrane technology cannot target specific elements and therefore ion exchange is much better suited where targeted element removal is required.
Multotec products are engineered to optimise costs, lifespan and efficiency of mineral plants.
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