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SGS Minerals Services provides a comprehensive range of consultative and testwork services to the iron ore industry.
We can help to:
- Improve production throughput
- Reduce costs
- Enhance product quality
With our step-by-step approach, we focus on turning our understanding of ore variability, flowsheet development and troubleshooting, piloting (either on-site or in our facility), product testing and plant improvements in materials handling or operations, into profitable plant performance.
Understanding Ore Variability
Ore variability impacts on plant performance and this has direct financial implications. SGS Minerals Services has a range of tools that can characterize and predict ore composition and the expertise to turn this into long-term recovery strategies. For instance, we can:
- Document ore composition and impurity levels
- Characterize ore grindability and liberation
- Determine mineralogical composition and texture
- Model or test metallurgical response to an existing flowsheet
- Implement metallurgical or plant improvements
Flowsheet Development or Troubleshooting
Developing the most effective processing flowsheet reduces the technical risk. Alternative options can be assessed and a conceptual flowsheet developed which is then tested and optimized. Changes in ore-type, technology or environmental regulations can mean that existing plants must revise their strategies.
Piloting
Pilot testing is the best way to reduce risk associated with a new flowsheet and generate the data needed to design the full scale plant. As well, existing operations can be simulated at the pilot scale to evaluate new technologies or address problems without interrupting production.
Materials Handling and Product Testing
Treatment of many iron ores is straightforward - crush and screen. Sometimes this is extended to include scrubbing, grinding and pelletising.
Quality control is the main concern in these plants, and SGS can assist with sampling, size analyses, chemical analysis, and other standard tests. When slurry or material flow is critical, thickening and filtration studies and rheology assessments can be performed, on in-plant streams, or samples shipped to our facilities.
Audit to Improve Metallurgical Performance
In more complex plants, a metallurgical audit can often indicate where improvements in plant performance can be achieved. For instance, a mineralogical study of various plant streams using techniques such as QEMSCAN or Image Analysis can highlight liberation problems, or areas with poor recovery. Improvement studies can then be focused in these areas.
If necessary, samples can be taken and metallurgical studies performed either on-site or at our facilities, with the equipment and reagents in the plant, or assessing alternative reagents or techniques. If necessary, these improvements can be demonstrated in an on-site pilot plant using a small feed stream taken from the critical part of the operation.
Audit to Increase Plant Throughput
Increasing plant throughput often improves profitability. Audits of the grinding and flotation areas can help address this. Grinding is usually one of the more prominent bottlenecks. SGS Minerals Services completes detailed grinding studies, using both power-based methods, and simulation-based methods to yield increased throughput, and/or improved fineness-of-grind.
As well, throughputs in the flotation area can be improved by reducing recycle loads, flotation rates or magnetic or gravity separation performance. This may be achieved by changing reagent regimes, improvement of feed particle size, and better control of pulp densities.
Facilities and Techniques Used in Iron Ore Metallurgical Processing
SGS Minerals Services has comprehensive laboratory and metallurgical testing facilities for iron ore in Australia and Canada.
Pilot-scale and bench-scale equipment is available to handle most processes encountered in the treatment of iron ores.
Mineralogy
Understanding how the ore and gangue minerals behave in the metallurgical processing requires qualitative and quantitative knowledge of ore and waste minerals present and their textures and associations.
SGS Minerals has X-ray diffraction, electron microprobe microscopy, QEMSCAN, image analysis and optical microscopy available to provide objective data.
Grinding
Beginning with bench-scale testwork, including Bond Rod and Ball Work Index, Bond abrasion index, Bond impact crushing index, MacPherson autogenous work index, SPI or JKTech drop-weight tests, we characterize the physical properties of the ore.
Well instrumented pilot scale autogenous grinding circuits, ball and rod mill circuits and crushing circuits are available for testing and design purposes. In-plant audits allow modeling and simulation of existing plants to assist in optimization.
Scrubbing
Rotary scrubbers and attrition scrubbers are available for the testing of lateritic iron ores.
Flotation
Reverse flotation is commonly used to remove silica and/or phosphate from hematite-magnetite ores.
SGS Minerals Services has strengths in both conventional cell and column flotation methods.
Magnetic Separation
A full range of magnetic separators is available for iron ore testing, from low intensity drum separators to high gradient/high intensity separators, and for either wet or dry feeds.
Gravity Separation
Spirals are the most practical equipment to use for gravity separation of iron ores because of the high throughputs needed. A variety of spiral test rigs are available, including the spiral designs typically used in iron-ore plants.
Accessory equipment allows sizing of feeds, multiple spiral stages, and recycling of products. Other gravity separation equipment, such as shaking tables, Falcon and Knelson centrifugal separators, Mozley MGS units, and hydrosizers, are available for specialty applications.
Selective Flocculation
Although not commonly used, selective flocculation has been successfully piloted at SGS Minerals Services for silicate removal from iron ores.
Pelletizing
A one-meter disc pellitizer is available for pellitizing testwork of fine iron ore products.
SGS Minerals Services' Iron Ore Experience
SGS Minerals Services has run over 20 semiautogenous grinding (SAG) and metallurgical pilot plants on iron ores, including extremely large plants treating up to 1,000 tonnes of ore and lasting for 6 months. Many complex circuits using autogenous grinding, de-sliming, magnetic separation, gravity separation, selective flocculation, and flotation have been run in our laboratories. Smaller pilot plant operations have been set-up on-site in major operating plants to test specific operations such as flotation, gravity separation, and thickening.
Other significant grinding testwork recently resulted in recommendations for circuit modifications and expansion of a large operating iron ore plant using modeling and simulation techniques following a plant audit of the grinding circuit.
As well, a continuous pilot plant circuit simulating the plant conditions can be mimiced to resolve in-plant problems. For instance, to the right is a plant set-up used to solve blinding problems of filter cloths after a flotation circuit. The problems were identified, resolved and changes recommended and subsequently made.
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