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For the iron ore exploration and mining industries, SGS Minerals Services provides a comprehensive range of metallurgical testwork services. Our extensive global network of laboratory and metallurgical testing facilities support most of the processes that are used in the exploration and treatment of iron ore.
Comminution
SGS Minerals Services supports the minerals and chemical industries in the design and operation of efficient crushing and grinding circuits using both power and model-based methods. We design circuits and provide operating advice to maximize milling efficiency, considering both steel and power consumption. Our practical experience also ensures that we recommend circuit configurations that offer ease of operation and maximum flexibility.
SGS Minerals Services' engineers have experience in operating SAG mill plants and have operated over 500 pilot-plant SAG circuits. This hands-on experience fosters a practical view of the design and operation of grinding circuits.
We have experience in many techniques, including the model-based approach and the empirical power-based approach, using the Bond and autogenous grindability tests. All data is analyzed and related to previous testing results. We compliment the JKTech models with mass-balancing, using the Bilmat program. We suggest that the most robust results are obtained when more than one approach to grinding circuit testing and design is used.
SGS Minerals Services can complete the following grindability tests:
- Bond Ball Mill Grindability Test
- Bond Impact Test
- Abrasion Test
- JK Drop-Weight Test
- MacPherson Autogenous Grindability Test
- MacPherson 18” Mill Test
Well-instrumented pilot-scale autogenous grinding circuits, ball and rod mill circuits, and crushing circuits are also available for testing and design purposes. In-plant audits allow modeling and simulation of existing plants to assist in optimization. Rotary scrubbers and attrition scrubbers are available to test lateritic iron ores.
Physical Mineral Separation / Beneficiation
Separation of certain minerals can be efficiently achieved by taking advantage of their physical, electrical and magnetic properties. For example, iron ore, mineral sands, coal, and diamonds are some minerals that use at least one of these extraction processes. The product can then be further upgraded by chemical (hydrometallurgy) or high-temperature techniques (pyrometallurgy).
All physical separation techniques can be tested at SGS, both on laboratory scale and pilot plant scale. The commonly used beneficiation techniques follow:
Gravity Separation
Spirals are the most practical equipment to use for gravity separation of iron ores because of the high throughputs needed. SGS has a variety of spiral test rigs, including the spiral designs typically used in iron-ore plants. Our 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 also available.
- Magnetic and Electrostatic 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.
- 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.
- Selective Flocculation
Although not commonly used, selective flocculation has been successfully piloted at SGS Minerals Services to remove silicate minerals from iron ores.
Hydrometallurgy
Hydrometallurgy is concerned with the principles and practice of the aqueous extraction of metals from natural or recycled resources and their subsequent recovery into useable products by means of environmentally sound and cost effective processes. Leaching rates, reagent consumption, temperature requirements and gas/pressure requirements can be determined through hydrometallurgical leaching test work including bench-scale autoclave work.
Conducting metallurgical leach testing can provide an indication of reagent costs, equipment requirements, indication of metallurgical amenability to leaching and also provide environmental considerations due to deleterious elements or even ARD. While hydrometallurgy is not regularly used in iron ore processing, SGS’ expertise can be used perform this work on a laboratory and pilot scale.
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