GoodRich offers a new technology from China, which can beneficiate low grades of hematite / limonite / goethite ores (including BHQ & BHJ) and also recover the left-over tailings from the conventional beneficiation plants, by converting them into magnetite ores, using the fluidised bed reduction-roasting method. Once the iron ore becomes magnetite, it is much easier to beneficiate & pelletise it.
The efficiency of iron recovery is 90-95% (as against 70-75% in the conventional beneficiation plants) & the left-over Fe in the tailings is only 10-15% (as against 35-45% in the conventional beneficiation plants).
In the process, low grade iron ores are dry-ground, preferably to their liberation size & passed through a fluidized bed roaster. The process uses coal gas for pre-heating & for partial reduction. Hematite / limonite / goethite ores get converted into magnetite ore in 1-10 minutes depending on the size of iron ore, at temperatures of 500-600 degree C. The left-over heat, after reduction, is utilized for 3 stage pre-heating of iron ore.
After being converted into magnetite, the ore is quenched in water & passed through low gauss magnetic separators, to reach 60-65% Fe grades. If the silica content is high, floatation process may also be employed.
Coal consumption is 90 kgs per ton of raw material (60 kgs by way of coal gas for reduction & 30 kgs by way of heat for drying). Power consumption is 40 KWh per ton for dry grinding in the ball mill (or 28 KWh in Raymond mill) and 20 KWh for other processes. The available plant capacities are from 200,000 tons to 1,000,000 tons per year, based on the input. After 50 years of research in this area, China has built the first plant of 200,000 tons per year, which is currently running well.
The apparent disadvantages of the above process are in addition to iron ore, coal is also needed & the capital investment on the beneficiation plant is comparatively high. However, looking at the fact that the recovery is higher& subsequent pelletisation needs lower capital investment and has lower production cost, reduction-roasting technology can be the future of beneficiation & pelletisation in India.
The hematite ore (Fe2O3) is always associated with limonite & goethite ores, which cannot be attracted by high gauss magnetic separators in the conventional beneficiation plants. Such tailings have 30-50% left-over Fe, which is a waste of natural resources. Large quantities of tailings are also environmentally hazardous, as they occupy more space & cause heavy metal contamination in the ground water.
Such tailings can be re-beneficiated, using the fluidised bed reduction-roasting technology & employing both pyro-metallurgical (reduction-roasting) & hydro-metallurgical (low gauss magnetic separation) processes. After re-beneficiation, the secondary tailings will have only 10-15% left-over Fe. These can be sold to the cement factories (when alumina contents are high in the tailings) or used for clay brick making.
Pelletisation is the process of formation of green balls (9-16 mm) by rolling the iron ore powder with a small quantity of binder & hardening the same by heat treatment in oxidizing conditions, up to temperatures of 1,250-1,350C. As a result, binding occurs & sufficient pellet strength is developed. The process includes feed preparation (grinding & pre-drying), mixing with the binder, balling by a disc pelletiser & hardening by drying, pre-heating, firing & cooling. Magnetite ore concentrate gets re-converted into hematite ore in the pelletisation, as it is an oxidation process. The hardening of pellets can be done by the vertical shaft kiln or travelling grate furnace cum rotary kiln.
The vertical shaft kiln needs lower investments &is suitable for small capacities of 100,000 tons to 600,000 tons per year. The thermal efficiency of todays vertical shaft kiln is equal to or better than that of the chain grate furnace cum rotary kiln.
Investments on vertical shaft kiln pellet plants are approximately 50% of the investments on chain grate furnace cum rotary kiln type pellet plants. The cost of making pellets will be only Rs. 750 per ton in the vertical shaft kiln, as against to Rs. 1,500 per ton in the chain grate furnace.
The investment on a 4,00,000 tons per year reduction roasting beneficiation plant, combined with 2,50,000 tons vertical shaft kiln pelletisation plant will be Rs. 75 crores & the estimated turnover is Rs.150 crores. Larger capacity plants of 1,000,000 tons per year of beneficiation & 600,000 tons per year of pelletisation need Rs. 150 crores of investment, with a turnover potential of Rs. 360 crores. The payback periods on these investments are 2-3 years.
Beneficiation of Iron Ore and the treatment of magnetic iron taconites, stage grinding and wet magnetic separation is standard practice. This also applies to iron ores of the non-magnetic type which after a reducing roast are amenable to magnetic separation. All such plants are large tonnage operations treating up to 50,000 tons per day and ultimately requiring grinding as fine as minus 500-mesh for liberation of the iron minerals from the siliceous gangue.
Magnetic separation methods are very efficient in making high recovery of the iron minerals, but production of iron concentrates with less than 8 to 10% silica in the magnetic cleaning stages becomes inefficient. It is here that flotation has proven most efficient. Wet magnetic finishers producing 63 to 64% Fe concentrates at 50-55% solids can go directly to the flotation section for silica removal down to 4 to 6% or even less. Low water requirements and positive silica removal with low iron losses makes flotation particularly attractive. Multistage cleaning steps generally are not necessary. Often roughing off the silica froth without further cleaning is adequate.
The iron ore beneficiation flowsheet presented is typical of the large tonnage magnetic taconite operations. Multi-parallel circuits are necessary, but for purposes of illustration and description a single circuit is shown and described.
The primary rod mill discharge at about minus 10- mesh is treated over wet magnetic cobbers where, on average magnetic taconite ore, about 1/3of the total tonnage is rejected as a non-magnetic tailing requiring no further treatment. The magnetic product removed by the cobbers may go direct to the ball mill or alternately may be pumped through a cyclone classifier. Cyclone underflows usually all plus 100 or 150 mesh, goes to the ball mill for further grinding. The mill discharge passes through a wet magnetic separator for further upgrading and also rejection of additional non-magnetic tailing. The ball mill and magnetic cleaner and cyclone all in closed circuit produce an iron enriched magnetic product 85 to 90% minus 325 mesh which is usually the case on finely disseminated taconites.
The finely ground enriched product from the initial stages of grinding and magnetic separation passes to a hydroclassifier to eliminate the large volume of water in the overflow. Some finely divided silica slime is also eliminated in this circuit. The hydroclassifier underflow is generally subjected to at least 3 stages of magnetic separation for further upgrading and production of additional final non-magnetic tailing. Magnetic concentrate at this point will usually contain 63 to 64% iron with 8 to 10% silica. Further silica removal at this point by magnetic separation becomes rather inefficient due to low magnetic separator capacity and their inability to reject middling particles.
The iron concentrate as it comes off the magnetic finishers is well flocculated due to magnetic action and usually contains 50-55% solids. This is ideal dilution for conditioning ahead of flotation. For best results it is necessary to pass the pulp through a demagnetizing coil to disperse the magnetic floes and thus render the pulp more amenable to flotation.
Feed to flotation for silica removal is diluted with fresh clean water to 35 to 40% solids. Being able to effectively float the silica and iron silicates at this relatively high solid content makes flotation particularly attractive.
For this separation Sub-A Flotation Machines of the open or free-flow type for rougher flotation are particularly desirable. Intense aeration of the deflocculated and dispersed pulp is necessary for removal of the finely divided silica and iron silicates in the froth product. A 6-cell No. 24 Free-FlowFlotation Machine will effectively treat 35 to 40 LTPH of iron concentrates down to the desired limit, usually 4 to 6% SiO2. Loss of iron in the froth is low. The rough froth may be cleaned and reflotated or reground and reprocessed if necessary.
A cationic reagent is usually all that is necessary to effectively activate and float the silica from the iron. Since no prior reagents have come in contact with thethoroughly washed and relatively slime free magnetic iron concentrates, the cationic reagent is fast acting and in somecases no prior conditioning ahead of the flotation cells is necessary.
A frother such as Methyl Isobutyl Carbinol or Heptinol is usually necessary to give a good froth condition in the flotation circuit. In some cases a dispersant such as Corn Products gum (sometimes causticized) is also helpful in depressing the iron. Typical requirements may be as follows:
One operation is presently using Aerosurf MG-98 Amine at the rate of .06 lbs/ton and 0.05 lbs/ton of MIBC (methyl isobutyl carbinol). Total reagent cost in this case is approximately 5 cents per ton of flotation product.
The high grade iron product, low in silica, discharging from the flotation circuit is remagnetized, thickened and filtered in the conventional manner with a disc filter down to 8 to 10% moisture prior to treatment in the pelletizing plant. Both the thickener and filter must be heavy duty units. Generally, in the large tonnage concentrators the thickener underflow at 70 to 72% solids is stored in large Turbine Type Agitators. Tanks up to 50 ft. in diameter x 40 ft. deep with 12 ft. diameter propellers are used to keep the pulp uniform. Such large units require on the order of 100 to 125 HP for thorough mixing the high solids ahead of filtration.
In addition to effective removal of silica with low water requirements flotation is a low cost separation, power-wise and also reagent wise. Maintenance is low since the finely divided magnetic taconite concentrate has proven to be rather non-abrasive. Even after a years operation very little wear is noticed on propellers and impellers.
A further advantage offered by flotation is the possibility of initially grinding coarser and producing a middling in the flotation section for retreatment. In place of initially grinding 85 to 90% minus 325, the grind if coarsened to 80-85% minus 325-mesh will result in greater initial tonnage treated per mill section. Considerable advantage is to be gained by this approach.
Free-Flow Sub-A Flotation is a solution to the effective removal of silica from magnetic taconite concentrates. Present plants are using this method to advantage and future installations will resort more and more to production of low silica iron concentrate for conversion into pellets.
The iron ore industries of India are expected to bring new technologies to cater to the need of the tremendous increase in demand for quality ores for steel making. With the high-grade ores depleting very fast, the focus is on the beneficiation of low-grade resources. However, most of these ores do not respond well to the conventional beneficiation techniquesused to achieve a suitable concentrate for steel and other metallurgical industries. The present communication discusses the beneficiation practices in the Indian context and the recent developments in alternative processing technologies such as reduction roasting, microwave-assisted heating, magnetic carrier technology and bio-beneficiation. Besides, the use of new collectors in iron ore flotation is also highlighted.
Before purchasing an ore beneficiation plant, people have lots of concerns: Which equipment I should choose to process my iron ore? Is this ore processing flowsheet best? Can these machines help me remove sulfur in iron ore beneficiation? Would they increase the recovery rate of tailings?
Then how to choose the right ore beneficiation plant depends on a lot of factors including physical properties of raw ore, capacity demands, final ore product requirements, geological situations of ore mines, and so on.
Here Fote Group would love to share valuable information about mining market trends, ways to build a high-quality ore beneficiation plant, and ten different ore processing plants which have been proved successful by our customers. If you have any most pressing questions and concerns, please contact our professional engineers who can make customized solutions according to your actual situation.
Our ore beneficiation plants sale to many countries, such as India, Australia, the USA, the UK, Canada, Switzerland, Philippines, Malaysia, Thailand, South Africa, Sudan, Egypt, Kenya, Indonesia, Nigeria, etc.
Nowadays, with ways of ore processing are getting more and more diversified and intelligent, the investment is not only limited to gold ore beneficiation but enlarged to many other items. From precious metals to coal, and to non-ferrous metals, investors can profit and bring more economic benefits to society.
Over 80 kinds of ores are widely used minerals in the world. Due to large output and high international trade volume, there are the several most common and important ores such as iron ore, copper ore, gold ore, bauxite, coal, lead&zinc ore, nickel ore, tin ore, and manganese ore, etc.
Nothing can replace iron ore in developing infrastructures as well as coal ore in the electricity industry, those ores making a great contribution to countries' economic growth. Gold ore mining ranks in a top position, attracting lots of investment for closed relations between the gold price and currency market.
The screening and crushing process is used to release useful minerals from the gangue. Different types of crushers reduce large sizes of raw ore into smaller ones, then vibrating screen with different mesh would help to get the desired size of ores. During the process, how many crushers need to be installed according to your real situation.
Usually, there are crushers with three crushing stages: primary crushers like jaw crushers, secondary crushers like cone crushers, roll crushers and impact crushers, tertiary crushers like compound crushers and fine crushers. Vibrating screens also have different types: Circular motion vibrating screens, horizontal Screens, high-frequency Screens, and trommel/ drum screens.
Only by crushers cannot get ore products with fine granularity, that's why mill grinding machines necessary in the beneficiation process. The mill grinding process is almost carried out in two consecutive stages: one is dry grinding (coarse grinding) and the other is wet grinding (fine grinding). The key grinding equipment are ball mills and rod mills, and the latter is now mostly used for wet grinding to finally produce fine and uniform ore products.
The beneficiation process is most crucial during the whole plant, helping people extract high value and pure ore concentrate products from ores no matter its grade high or low. The beneficiation process can be carried out in a variety of ways as needed but you ought to select a piece of optimal equipment to avoid inefficiency and waste in the entire process. The most common beneficiation equipment includes flotation machines, electrostatic and magnetic separators, and gravity beneficiation equipment.
Ore drying equipment may appear in any stage of a mineral processing plant (from raw ore-concentrate-finished product). The purpose of drying is to remove the moisture contained in the ore, ensuring the integrity of the product, and maximizing the value. In addition, drying process can also reduce product transportation costs and improve the economic efficiency of storage and processing.
With almost 50 years' extensive experience, Fote engineers are professional in integrating, designing, fabricating, commissioning, maintaining, and troubleshooting various beneficiation plants. The company aims to provide customers with the best mining equipment and the most reasonable beneficiation plants. Its final goal is to increase the potential profit that customers can obtain from the ore and enable mining companies to improve the overall profitability.
5TPH low-grade gold ore beneficiation plant in India 10 TPH gold ore beneficiation plant in South Africa 20-35TPH gold ore beneficiation plant in Egypt 10 TPH iron ore beneficiation plant in the USA 10-50TPH copper ore beneficiation plant in Pakistan 50-100TPH manganese ore beneficiation plant in Kenya 150TPH Bauxite ore beneficiation plant in Indonesia 50TPH lateritic nickel ore beneficiation plant in Philippines 200TPH zinc & lead ore beneficiation plant in Nigeria 250TPH chrome ore beneficiation plant in Russia
As a leading mining machinery manufacturer and exporter in China, we are always here to provide you with high quality products and better services. Welcome to contact us through one of the following ways or visit our company and factories.
Based on the high quality and complete after-sales service, our products have been exported to more than 120 countries and regions. Fote Machinery has been the choice of more than 200,000 customers.
Energise Minerals proposes to set up a 2.75 MTPA Iron Ore Beneficiation plant and 1.2 MTPA Pellet plant at Rairangpur, District: Mayurbhanj. The Odisha SLSWCA has recently gave an in-principle approval to the project, at its 99th meeting held in March 2021.
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We know that not all Iron Ore deposits are the same and changing commodities prices are placing higher demands on producers to sweat the assets through process improvements, and increase revenues by converting tailings. Thats why understanding your project objectives and opportunities is our first step in developing solutions that transform your ores into valuable commodities. This holds true for all projects that we are involved in and forms the basis for our ongoing work in developing and delivering innovative and cost effectiveprocess solutionsacross the project lifecyclethat transform your ore bodies into valuable commodities.
To be confident in investing in a project, you need to know that the separation process will work on start-up and throughout the life of the operation. We give you certainty by testing representative samples and analysing the results beyond basic calculations to deliver innovative and cost effective process flowsheets that maximise the grade and recovery of valuable minerals including Magnetite, Hematite and Goethite.
Customers value our 75 years experience in metallurgical testing, whether performed in our extensive metallurgical test laboratory in Australia or, under our direction, in partner test laboratories in the USA, South Africa, Brasil and India.
We routinely test samples as small as 100 grams for characterisation and specific gravity fractionation, through to larger samples up to 2000 kg for bench and pilot scale testing and flowsheet development. We also have the capability to create multi-stage pilot scale circuits to treat bulk samples (80-100 tonnes) for process testing and circuit optimisation and our test equipment includes the latest gravity, electrostatic and magnetic equipment.
High grade concentrates and high recovery of iron ore can be achieved using effective feed preparation systems (typically controlled crushing, screening, milling, classification and slimes removal) in combination with cost effective, efficient metallurgical separation.
Hard rock hematite deposits often require a combination of milling, screening and on occasion, fine classification to prepare a finely sized (-1.0mm), liberated feed for beneficiation by gravity separation. This is typically followed by re-grinding of the tailings to liberate more hematite for further iron unit recovery by magnetic separation.
WHIMS are also often employed to recover fine hematite from spiral circuit tailings. The inclusion of medium intensity magnetic drum separation (MIMS) in combination with jigging may be considered for the beneficiation of the 6-1mm fraction of some friable ore bodies.
Having developed an effective and optimised flowsheet, you need a plant that safely and effectively applies this flowsheet to the ore body to extract high grade iron ore whilst delivering high availability, with low capital and low operational expenditure.
For this reason our equipment is designed and manufactured using the latest technologies and is fully tested in processing operations to ensure maximum performance. This means that when we release new process equipment you can be assured that it will be fit for purpose and cost effective.
A good example is the engineering we completed for ArcelorMittals projects in Canada and Africa. The specific ore required our teams to design a High Capacity wash water spiral which becames the HC33.
As a world leader in process solutions we have delivered some of the largest and most complex projects including design of the worlds largest wet concentrating plant at the ArcelorMittal project, and the design and supply of two tailings treatment beneficiationplants for Arrium in Australia.Get in Touch with Mechanic