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SGS Minerals Services has a group of highly experienced engineers and technologists who are ready to provide your process development team with solutions to your solvent extraction and electrowinning processing challenges.
SGS Minerals Services' SX-EW team has the expertise and experience to accurately execute your testwork requirements in a timely manner. From bench-scale process testwork to continuous piloting, our SX-EW team can develop and pilot your flowsheet either in stand-alone SX-EW circuits, or as part of larger integrated hydrometallurgical circuits that may include a number of other unit processes such as leaching, impurity removal or liquid/solid separation.
SOLVENT EXTRACTION BENCH-SCALE STUDIES
SGS Minerals Services' personnel have carried out many bench-scale studies to recover a wide range of metals from leach liquors and other process solutions. The types of testwork that are commonly performed include:
- Determination of phase disengagement and separation times
- Chemical and physical organic scrubbing studies
- Evaluation of physical properties (densities and viscosities)
- Determination of equilibrium isotherm (extract and strip
- pH profiles to determine effect of pH on metal distribution
- Effect of reagent concentration
- Evaluation of maximum loading and effective organic reagent concentration
- Evaluation of the effect of temperature
- Determination of kinetics (extraction and stripping)
- Effect of phase continuity
- Determination of settler scale-up factors using a variable area settler
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SOLVENT EXTRACTION PILOTING EQUIPMENT
SGS Minerals Services has in-house, or can build to suit, a variety of equipment that can be used for your pilot circuit and to match the size of the SX-EW circuit to your process development and piloting requirements.
The equipment is available in a variety of materials of construction to meet process chemistry demands. In-house equipment already available includes:
Mixer-settlers with mixer volumes from 180 mL to 18 L. All Units:
- Have minor phase (aqueous or organic) recycle capabilities
- Can be heated for operation at desired temperatures
- Can be operated with pH and/or ORP control
- Are equipped with variable speed drives that maintain a set speed even under conditions of changing load
- Are designed to provide variable holdup volumes to give a range of residence times without replacing units
Bateman® Pulsed Column countercurrent contactor, optionally equipped with pH/ORP and temperature control (40 mm diameter × 4 m high mixing zone Lakefield)
Karr® Reciprocating Plate countercurrent contactor optionally equipped with external settler for operation in co-current mode (25 mm diameter × 2.75 m high mixing zone (Lakefield & (Perth) Scheibel® Column countercurrent contactor (75 mm) Diameter × 1.5 m mixing zone (Perth)
Sieve Plate Pulsed Column countercurrent contactor (75 mm diameter × 4 m high mixing zone (Perth)) Aqueous feed filtration and pre-treatment systems
Organic coalescers (sand and mixed media) for removal of traces of entrained organic from aqueous streams Graesser Raining Bucket Contactor Lightnin’ Mixco pilot plant unit
In addition, we also have access to:
- Podbielniak Centrifugal Contactor
- Krebs mixer-settler 5-stage contacting unit
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ELECTROWINNING EQUIPMENT
SGS Minerals Services can furnish a variety of electrowinning cells, power supplies and electrode materials that can be operated as stand-alone electrowinning units, or in conjunction with SX or other solution purification circuits. Cells can be equipped with temperature control and electrolyte recirculation systems where necessary. The equipment includes:
- Electrowinning cells ranging in size from tens of mL to over 250L
- Stainless steel, stainless steel wool, steel wool, aluminum and titanium (various Ti alloys) cathodes. Other materials can be readily sourced as required. Cathodes up to 50 cm × 50 cm (1/4 m2) or commercial size cathodes up to 1m2 are produced
- Pb/Ca/Sn, Pb/Ag, graphite and inert DSA anodes.
- Other materials can be readily sourced as required
- Anode bag systems and cells where anode and cathode compartments are separated by a physical or ion-selective membrane
- Cathode bag systems and cells for isolation of the catholyte from the bulk of the cell solution
- Constant current DC rectifiers from bench scale to 12000 W output
Our Australian laboratories have also developed the Jetcell® proprietary electrowinning apparatus which has wide potential application for electrowinning of metal powders, with advantages including superior current efficiencies and reduced operating costs.
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REAGENT SUPPLIES
SGS Minerals Services maintains an extensive on-site inventory of major solvent extraction reagents, diluents and modifiers including oximes, amines and phosphoric/phosphonic acids. In addition, through an active network of contacts with reagent manufacturers and suppliers, fresh reagent can be sourced readily.
We also maintain a supply of common electrowinning additives such as guar gums and have ready access to specific reagents.
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CUSTOM SETUPS
SGS Minerals Services can design, specify and erect custom cell configurations for SX or EW in materials selected specifically for resistance to process chemistry conditions. Through linkages with metal and plastic fabricators, such equipment can be designed and fabricated rapidly to expedite the construction of pilot circuits.
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MODULAR PILOT PLANTS
SX and EW equipment can be assembled and skid or container mounted for transfer to an operation at remote sites. For instance, modular SX pilot circuits have been operated in northern Canada and in Cuba.
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ANALYTICAL SUPPORT
Dedicated analytical capability on-site at the piloting laboratory leads to lower turnaround times. At SGS Minerals Services, SX-EW operators carry out basic control sample analysis in “real time” using dedicated instrumentation or classical techniques. The turnaround time for more complex determinations is minimized through use of the on-site analytical capability. This helps our clients operate continuous piloting campaigns that maximise the effective use of their budgeted funds. A client can then make more controlled and informed changes to operating conditions and study a wider range of operating parameters in a given time. The process operators can respond quickly to upstream process changes in integrated circuits.
SGS laboratories maintain in-house analytical capabilities that provide analytical data to pilot plant operations in the shortest possible turnaround times. These capabilities typically include:
Metals determinations in aqueous solutions, both at macro (up to 100’s of g/L) and micro (mg/L or lower) levels metals in organic solutions such as SX extractant mixtures Furthermore, the SGS Lakefield Canada site has more extensive analytical facilities. In relation to SX-EW testwork, this includes:
- Anion determinations in aqueous solutions
- Trace organics in aqueous samples, for example to determine organic losses
- Analysis of crud solids, both chemically and mineralogically
- Process mineralogy of precipitated solids
- Determination of trace and minor elements in plated metal deposits
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PROCESS MODELLING
Through our linkages with copper extractant manufacturers, we have access to solvent extraction flowsheet simulations using proprietary reagent data that can be applied to the client’s data to investigate various flowsheet options and scenarios. We also have access to process modelling capabilities using AspenTM and MetsimTM software packages.
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PROCESS CONTROL AND DATA ACQUISITION SUPPORT
The SGS Minerals Services Canadian facilities are equipped with a Bailey process control system. This system can be configured to acquire key operating data during piloting runs, for example pH, temperature or cell voltage among others, so that maintenance of accurate and systematic records is ensured, and trends can be monitored in real time.
The Bailey system can also monitor and control important operating units to ensure that deviations from set points are recognised without delay and attended to either by operators or automatically.
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EXPERIENCE
Our personnel have carried out a variety of bench-scale studies on various aspects of solvent extraction and electrowinning circuits. They have operated all types of equipment listed above in continuous piloting campaigns under a variety of operating conditions. Examples of recent work include:
For more information, please contact our Solvent Extraction and Electrowinning Experts
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