Title of Invention

PROCESS OF RECOVERING USABLE ORE FINES FROM IRON ORE TAILINGS

Abstract

Iron ore tailings contain iron concentration around 45%. In future it may become economically viable to extract iron content from tailings. But due to huge land cost and other environmental factors it is worthwhile to examine the feasibility to minimize the tailings volume. This research examines the feasibility of the recovery of resources from tailings and focuses on the reduction in tailings volume as part of environmental management strategy. A process has been developed and applied successfully in the Barsua iron ore mines of Orissa to solve its industrial problem . Adopting the process and with the use of Wet High Intensity Magnetic Separator (WHIMS) and it could be possible to improve the Fe content in the recovered ore from 45% to 64% and Al2O3 as well as SiO2 can be reduced to 2.20% and 2.75% respectively which can be utilized as resource for iron and steel making with 50% recovery from tailings. Thus a substantial amount, can be recovered as resource, which can be used as a sinter feed for making iron and steel It also reduces the tailing volume as well by adding those additional units to beneficiation plant. Sintering test was done with the recovered ore fines, which are mixed with fresh iron ore sinter feed at different proportions, tested and the optimum proportion (up to 20%) has been evaluated in which there would be no adverse effect on the physical and metallurgical characteristics of the sinter . This invention provides a sort of fundamental new scientific insight for the utilization of tailings as resource and environmental protection as well. The process developed has formed a guideline and can be utilized on an industrial scale for various sites

Full Text

1.0 Field of investigation This invention relates to a noble method of recovering of useable ore fines from iron ore tailings as resource. The invention provides a sort of fundamental new scientific insight for the utilization of recovered ores from tailings and environmental protection as well. 2.0 Background of the invention Extraction of minerals generates solid waste consisting of overburden material, sub grade ore and tailings. The iron ore extracted from the mines are beneficiated to separate the valuable mineral content. Tailings are ground rock particles, which are produced during beneficiation of ore and disposed in slurry form in tailing pods. Tailing particles are usually sound and angular . Even ground particles extending well into silt size range show remarkable angularity. Almost 32% of iron ore ends up as tailings. The fine tailings generated are usually disposed off in tailing ponds for containment, which have adverse impacts on environment. The increase in production of iron ore results in the acceleration of the rate of generation of tailings, requiring proper planning for their safe disposal. The graveness of the problem due to the disposal of tailings from iron ore mines in India can be easily appreciated if we analyze the projected production of iron ore and associated tailings to be disposed off. In 1991-92, 57.10 Mt iron ore were produced, which generated 18.14 Mt tailings. By 2000 AD iron ore production was 85 Mt generating 27 Mt of tailings. Tailings from iron ore beneficiation process represent one of the biggest waste handling problems to the industry. There exists global awareness about the conservation of mineral resources and the environment. The national mineral policy of Govt, of India (GOI) stresses the need for the proper disposal of the tailings. The graveness of the problem due to the disposal of the tailings from iron ore mines in India can be appreciated if the projected production of iron ore and associated tailings to be disposed off are analyzed. The management of tailings in an environmentally responsible manner upholds the principles of sustainable developments. The environmentally responsible management of tailings is best achieved by environmental impact assessment (EIA), before the tailing dam is started . The availability of land for disposal of tailings is a problem of concern. The creation of artificial tailing ponds for containment of iron ore tailings creates environmental problems. Two factors have a dominating influence in the environment, namely, the surface stability of the impoundment and the quality of the water emanating from it. The stability must be acceptable not only during operation but also after decommissioning and closure. Tailing embankments are susceptible to rapid erosion; down cutting and complete breaching and shortly after rainfall water overtops the crest. Another cause of surface water pollution is the discharge of supernatant of tailing pond effluent into a watercourse The risk of contamination of an aquifer by contaminants leaving the tailing deposits also exists. Ferrous mining sector, which generates huge tailing volume, needs huge land space for accommodating this residual product. The management of tailings from iron ore mines is an important issue, not only from the point of view of pollution control, but also keeping conservation of resource in mind. It has been found that iron ore tailings still contain iron concentration of 40-50%. Based on present day techno economic considerations it may not be worthwhile to extract the iron constituent from this lean source but in future when the present day rich resource will die down, it may become economically viable to extract iron content. However, due to huge land cost and also keeping in mind that forestland, which is found normally around iron ore mines , it is worthwhile to examine the feasibility to minimize the pondage volume . This accumulated waste product ultimately could be the resource for mineral extraction in future time, when present day rich resources will be fully exploited. This background has called for a thorough investigation to make an innovative process development to recover valuable ore fines from iron ore tailings as resource vis-a-vis reduction of tailings volume as a of part sustainable management practice. 3.0 Drawback associated with the known art The iron ore extracted from the mines are beneficiated to separate the valuable mineral! content. Depending on the type of iron ore, if Fe content is nearly or more than 60% and having alumina and silica within limits, it is only crushed and screened to size and can be sent directly to metallurgical plant without beneficiation. In case the impurities i.e. silica and alumina are present beyond the acceptable limits, the ore is beneficiated by crushing, screening, grinding, washing, classifying jigging, cycloning, processing in the magnetic separator etc. depending on the type of ore. The reject portion of the iron ore is left after the beneficiation process, of coarse, are fine particles in water in a slurry form, known as wet tailings and are needed to be disposed off. The increase in production of iron ore results in the acceleration of the rate of generation of tailings, requiring proper planning for their safe disposal. Tailings are defined as ground rock particles that are produced during ore beneficiation and disposed in slurry form. The tailing slurry is usually abrasive and has high viscosity. In the ore processing and beneficiation plants, the fine tailings generated are usually disposed off in tailing ponds. Tailings from iron ore process represent one of the biggest waste handling problems of the industry due to the quality of the tailings and very large volumes that are produced. The graveness of the problem due to the disposal of tailings from iron ore mines in India can be easily appreciated if we analyze the projected production of iron ore and associated tailings to be disposed off. In 1991-92, 57.10 Mt iron ore were produced, which generated 18.14 Mt tailings. By 2000 AD iron ore production was 85 Mt generating 27 Mt of tailings. The availability of land for disposal of tailings is a problem of concern. The creation of artificial tailing ponds for containment of iron ore tailings creates environmental problems. Two factors have a dominating influence in the environment, namely, the surface stability of the impoundment and the quality of the water emanating from it. The stability must be acceptable not only during operation but also after decommissioning and closure. Tailing embankments are susceptible to rapid erosion; down cutting and complete breaching and shortly after rainfall water overtops the crest. Another cause of surface water pollution is the discharge of supernatant of tailing pond effluent into a watercourse. The risk of contamination of an aquifer by contaminants leaving the tailing deposits also exists. Ferrous mining sector, which generates huge tailing volume, needs huge land space for accommodating this residual product. The management of tailings from iron ore mines is an important issue, not only from the point of view of pollution control, but also keeping conservation of resource in mind. A fact finding investigation is essential to recover usable ore fines from this tailings. Tailings are defined as ground rock particles that are produced during ore beneficiation and are disposed off in slurry form. The tailing slurry is usually abrasive and has high viscosity. In the ore processing and beneficiation plants, the fine tailings generated are usually disposed off in tailing ponds. Tailings from iron ore process represent one of the biggest waste handling problems of the industry due to the quality of the tailings and very large volumes that are produced. The physical and chemical nature of the effluent coming out of beneficiation plant, depends on the type of ore being treated, the milling operations used to beneficiate the ore and the water content in the effluent. The particle size is the most important characteristics of the beneficiation plant effluent. The nomenclature for particle size fraction generally adopted as per internationally accepted system adopted by British Standard. In India, in the Kudermukh Iron Ore Company the magnetite iron ore is beneficiated by gravity separation in spirals and by magnetic separation. Approximate mineralogical composition is Fe 35% and silica 60 to 65% having specific gravity of 2.75. On the other hand iron ore mines of National Mineral Development Corporation at Bailadila, generates dry tailings of 2700 t per day and disposed with 7500 m3 of water having 27-30% solid to liquid ratio. The other characteristics are TDS 250 ppm, ore fines 95% and 5%, clay, silica materials having - 10-mesh size 25% and - 100 mesh size 75%). Tailings released from beneficiation plant thickener under flow and from other operations are hydraulically transported to the tailing pond for containment. The tailing discharged to the disposal site varies in quality as far as its consistency is concerned, depending on the process adopted in the beneficiation plant. The tailings are generally dewatered prior to transport and disposal, but more than equal weight of water may remain with solids with slurry mixture. From thickener underflow the water content is generally limited to 40% by weight. Different mines produce the tailings of different properties. The most environmentally concerning properties are (i) Residual metal level (ii) Presence of sulphide minerals (iii) Presence of reagents used in beneficiation and thickening process The hazardous component in the tailings includes (IBM, 1994) • Heavy metal cations: Sb, As, Cd, Cr, Pb, Zn, Ni, Cu, Mn • Heavy metal anions: Chromates, Chromites • Non metallic anions: Cyanides, sulphides, theocyanates • Organics: Hydrocarbons, organic acids, organic peroxides, esters, alcohol's, aldehydes, phenols, chlorocarbonates, amines, pyridines, organic sulphur, compounds, alkaloids, steroids. General pollution is due to the increase of suspended solids in case of improper decantation in the tailing pond. The most significant environmental impacts associated with tailing dam are as follows. Serious concern in this regard is direct discharge of tailings into rivers be practiced in a number of countries including India. Widespread destruction of fluvial marine environment is usually the result. The mere construction of a tailing pond is no guarantee of environmental compliance in this regard. The lack of seismic and even static stability of a dam may result in much more catastrophic destruction of both human and natural environment. Another cause of pollution of surface water is the discharge of excess supernatant effluent into a watercourse. When the discharge of tailing effluent is acidic it usually carries with a greater load of contaminants in solution form and pose greater threat to surface water body. Many countries have legislation requiring or at least encouraging a zero effluent discharge practice. In arid regions, where surface water resources are scarce, great reliance is placed on ground water, which is often fossil water. The location and control of tailing deposits must take careful cognizance of potential impact on ground water aquifers. The risk of contamination of an aquifer by contaminants leaving the tailing deposits exists. The major short term and long-term environmental problems associated with tailings storage related to • Water pollution (including ground water) • Dam safety and stability • Air pollution by dust • Visual impact • Reclamation and restoration (Australian Federal Env. Dept., 1995) Tailing dam subcommittee of SANCOLD. (South African National Committee On Large Dams) on their report on "Environmental Aspects on Tailing Dams" identified significant negative environmental impact associated with tailing dams are as fallows. 1. When the discharge of tailing effluent is acidic, it usually carries with its contaminants in solution particularly heavy metals. 2. The risk of contamination of a aquifer by contaminant leaving the tailing deposits should be assessed. Some cases may need liner, leachate detection measures and ground water monitoring. 3. To reduce wind blown dust, operating practices and capping, revegatation efforts are needed. Attempt shall be made to maintain a moist tailing environment to reduce wind erosion. Some times tailing water contains some hazardous chemicals used during beneficiations process, which may adversely affect the adjacent area near tailing pond. Other aspects requiring consideration in tailing pond design is site selection. These drawbacks associated with the known art have initiated to invent a novel scientific method to solve the problems. 4.0 Object of invention Iron ore tailings contain iron concentration around 45%. These hematite in nature with having feebly magnetic properties. The object of this invention is to develop a suitable method , which may become economically viable to extract iron content from these tailings. Due to huge land cost and other environmental factors it is worthwhile to examine the feasibility to minimize the tailings volume. This research examines the feasibility of the recovery of resources from tailings and focuses on the reduction in tailings volume as part of environmental management strategy. No national plan or design for tailing disposal can be carried through without an appreciation of the physical nature and chemical characteristics the liquid beneficiation plant effluent. The combined physical and chemical properties of the material dictate on the most fundamental level, the type of disposal facility required and the degree of conservation in its design, consistent with the hazard posed by the materials. Understanding of the tailings begins with knowledge of process by which they are produced, and even a limited familiarity with this process can give important clues to the nature of the tailings. While tailing characteristics vary over wide ranges in nearly every respect, the type of ore being processed usually allows for some reasonable valid generalizations about the physical nature of the material. In physical characteristics it is essential to relate the solid, liquid and air phases of the mass material whether in slurry or settled solid form. Relative density provides a useful description for in-place density in relation to loosest and densest status that the tailings may attain. Various investigators have determined the maximum and minimum densities. Concentration of iron ore tailings is usually done by gravity separation often followed by magnetic separation. These concentration processes result in relatively coarse tailings almost exclusively in the sand size range. At some operations, further concentration by flotation methods is performed to liberate additional low grade or magnetic mineralization. Flotation requires crushing to very fine sizes. Where both fine and coarse tailings are produced, the fine tailings usually predominate in terms of volume. The difference in gradation is immediately apparent. However, Guerra reports both types of materials to be nonplastic. Specific gravities reported by Guerra for fine particles to be 3.00-3.4 and coarse particles to be 3.0 . Kolhn reported the specific gravities of fine particles to be 3.1. The tailing characteristics vary over wide range. However, the type of ore being processed usually gives an understanding about the general physical nature of the material. In much the same way, a basic understanding of the processing techniques can give the useful indications of the types of chemical constituents to be expected in the liquid effluent. Here, however, it is necessary to account for not only the types of contaminants but also their expected concentrations. The potential hazard posed by specific contaminants at specific concentration can be judged only in the context of individual toxicity levels. The physical nature of tailings can not be separately considered in isolation without considering associated mill effluent from beneficiation plant. However, pH is often a useful indication of the general types of contaminants in the effluent. The management of tailings from iron ore mines is an important issue, not only from the point of view of pollution control, but also keeping conservation of resource in mind. It has been found that iron ore tailings still contain iron concentration of 40-50%. Based on present day techno economic considerations it may not be worthwhile to extract the iron constituent from this lean source but in future when the present day rich resource will die down, it may not become economically viable to extract iron content. However, due to huge land cost and also keeping in mind that forestland. which is found normally around iron ore mines, it is worthwhile to examine the feasibility to minimize the pondage volume. A pilot scale study was conducted with the use of WHIMS plant. The study reveals that on tailings management point of view, reduction of tailing volume is feasible if maximum iron content is extracted. It was reported that WHIMS process is preferable in comparison to Flotation Process. 5.0 A summary of invention A scheme for further recovery of usable ore fines from tailings produces from iron ore beneficiation plant as resource has been developed . At the same time the volume of tailings will be reduced substantially and will extend the life of tailing pond. It will also make available for the recovered fines for use as sinter feed. This scheme may be considered as an ultimate strategy for environmental management for tailing disposal as it will reduce pressure on utilization of land space. In this regard the available technologies are Wet High Intensity Magnetic Separation (WHIMS) and Flotation Processes. However, WHIMS process is preferable in comparison to Flotation process since disposal of flotation pulp containing residual reagents contributes to pollution of water regime. The following specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed • WHIMS can be used for the separation or concentration of weakly magnetic materials. Commercial models, ranging in capacity from 1 to 120 t/h are available. Preliminary feasibility testing is to be done on batch type WHIMS plant with a small representative sample of material. Pilot scale test work is to be done on the continuous type model WHIMS plant. • On continuous type model high gradient high intensity magnetic fields needed to separate or to concentrate feebly, magnetic materials. These are to be generated by oil-cooled coils, each with expansion tank and relief valve. The coils are to be enclosed completely to protect them from moisture, chemicals and other elements. • A background field from 7,000 to 10,000 gauss in the open-air gap is to be produced by these coils. This will saturate the matrix and result in fields of 2 Tesla or more in the separation zone. • The matrix will be of select type of magnetic soft iron that fill the moving part and will produce the gradient to hold feebly magnetic particles, while allowing non- magnetic particles to pass through when the matrix area will be in the magnetic field. • Slurry feed is to be introduced into the magnetic matrix, which is contained in a stainless steel ring moving at controlled speed between the poles of powerful stationary electromagnets. The variable drive system is to be located under the ring to allow full visibility of the separation area. • The feed pulp is to be entered the matrix just ahead of each magnetic zone, and as the magnetically susceptible particles will flow down through the highly induced expanded metal grid they will be attracted and held. Most of the non-magnetic particles will be passed right through to the discharge tray by the drag force of the slurry water. To assist the further flow of the non-magnetic particles, a low pressure water rinse spray is to be directed to the ring at the tailing edge (just beyond the feed point) of the magnetic field to dislodge additional physically entrapped non-magnetics. • As the rotating ring moves the matrices, elements loaded with magnetic particles out of the field remaining in the material grid drops sharply and high pressure water spray will rinse the magnetic material into the discharge tray. Adjustable dividers in the compartmented discharge tray will separate the middleings and magnetic fractions. • The cyclone underflow and thickener underflow can be fed to WHIMS plant for recovery of ore fines. In order to find out the efficiency of WHIMS, the tailing slime is to be subjected to laboratory scale test. By subjecting the tailings to 2- stage cycloning, sample of filter cake is to be prepared. Filter cake and slime samples are to be sent for WHIMS test. • Since it is important to establish the effect of magnetic intensity on the feed material, particularly in view of the wide range of magnetic susceptibility of the iron oxides present in the same, series of test are to be conducted with varying gaps and varying magnetic current. It has been established that there will be appreciable recovery with a 1.8 mm gap at 14 amphere current. • Sincering test are to be carried out with WHIMS concentrate to confirm the possibility to utilize the concentrate in the sinter mix without adversely affecting the physical and metallurgical characteristics of the sinter. 6.0 A brief description of the accompanying drawing The user agencies are different iron ore mines. For the application of this invention Barsua iron ore tailing slime was subjected to laboratory scale WHIMS test. By subjecting the tailing slime to 2-stage cycloning, it was possible to produce concentrate having 58.9% Fe, 5.25% SiO2 and 5.51% Al2O3. To investigate the possibility of further up gradation filter cake obtained by 2-stage cycloning and subsequently the slime samples wire sent for WHIMS tests by M/s. Jonnes Fero Magnetics Inc. (JFMI), Switzerland. The test results indicated that the Fe content in filter cake can be increased from about 59% to 63/64% and AI2O3 as well as silica can be reduced by 50%. The results in respect of quality and recovery, obtained from tests on slimes are similar to those obtained with filter cake. It is envisaged that annually about 317,000t of slime will be produced in the beneficiation plant, considering a benefiable ore (B.O) to direct ore (D.O) ratio 50:50 and slime loss of 30%. The chemical analysis of concentrate as well as the weight of Fe recoveries expected is given below: Sintering tests were carried out by Research and Development Centre for Iron Steel (RDCIS), Ranchi with WHIMS concentrate, confirmed that it would be possible to utilize the concentrate to an extent of about 20% in the sinter mix without adversely affecting the physical and metallurgical characteristics of the sinter. The prepared scheme has been shown in Figure 1. 7.0 Detailed description of the invention: For the application of this work Barsua iron ore tailing slime was subjected to laboratory scale WHIMS test. The waste arising of the order of 5,00,000 t/y in the form of jig tailings, slime from the cyclone underflow and thickener underflow. The existing tailing pond, originally designed to handle 4-5 years slime disposal, was totally utilized to its maximum capacity. To augment the capacity of the tailing pond by raising the height of existing dam in two stages of 5m each was conceived By subjecting the tailing slime to 2- stage cycloning, it was possible to produce concentrate having 58.9% Fe, 5.25% SiO2 and 5.51% Al2O3. To investigate the possibility of further up gradation filter cake obtained by 2- stage cycloning and subsequently the slime samples were sent for WHIMS tests by M/s. Jonnes Fero Magnetics Inc. (JFMI), Switzerland. The test results indicated that the Fe content in filter cake can be increased from about 59% to 63/64% and Al2O3 as well as silica can be reduced by 50%. It is envisaged that annually about 317,000 t of slime will be produced in the beneficiation plant. Sintering tests were carried out by Research and Development Centre for Iron Steel (RDCIS), Ranchi with WHIMS concentrate, confirmed that it would be possible to utilize the concentrate to an extent of about 20% in the sinter mix without adversely affecting the physical and metallurgical characteristics of the sinter. This scheme for further recovery of usable ore fines from tailing slime will extend the life of tailing pond. It will also make available to the recovered fines for use as sinter feed. This scheme may be considered as a resource recovery from tailings and as an ultimate strategy for environment management for tailings disposal as it will reduce pressure on utilization of land space. Besides other advantages, installation of WHIMS plant also will enable to reduce appreciably the impact of tailings on the environment. It has been estimated for Basua Iron Ore Mines that with the present rate of plant utilization and consequent generation of tailings, an additional 5 acres of land consisting mostly of reserve forests get affected every year. Further, at the present rate of discharge, the tailing pond at 2nd stage may get filled up within 8 years. Then it will become imperative to construct a new tailing pond for which acquisition of land at a new site may be required. In view of stringent forest laws and restriction on the use of forestland for non-forest purposes . This situation calls for adaptation of a suitable process, which enables reduction in discharging tailings. Installation of WHIMS plant will enable recovery of substantial quantity of fines from tailings thereby reducing the quantity of tailings discharged to the environment by about 50%. As a result, the rate of inundation of forestland and consequent damage to trees may get reduced to a great extent. Besides, the life of the existing pond may be extended and construction of a new pond as well as encroachment/invasion on fresh forestland will get deferred substantially. Moreover, the size of the new pond will get reduced and thus the requirement of forestland is for tailings disposal will come down considerably. In view of the foregoing, WHIMS process may be considered as a positive environment management to save land space for tailing pond and also to recover the usable ore fines form tailings for recycling and reuse. Though the tailings are considered to be the wastes and rejects, the new interpretation of the fact is that these are the resources for the future, which are to be conserved in tailing ponds Thus 50% of tailing volume, a substantial amount, can be recovered as resource, which can be used as a sinter feed for making iron and steel and also resulting in the reduction of tailing volume. In addition to the economic benefit to the utilization of waste as resource, it will also minimize the cost of additional land requirement, land degradation surface and ground water pollution, destruction of forest, impact on social life, human health and safety. This is significant in terms of resource recovery from waste and environmental protection. These socioeconomic and environmental benefits will be of great interest to the general public. Besides other advantages, installation of WHIMS plant will also enable to reduce tailings volume appreciably . It has been estimated for Basna iron ore mines, with the present rate of plant utilization and consequent generation of tailings, that an additional 5 acres of land consisting mostly of reserve forests get affected every year. Further, at the present rate of discharge, the tailing pond at 2nd stage may get filled up within 8 years. Then it will become imperative to construct a new tailing pond for which acquisition of land at a new site may be required. In view of stringent forest laws and restriction on the use of forest land for non forest purposes, it is desirable that such acquisition should be limited to a minimum. This situation calls for adaptation of a suitable process, which enables reduction in discharging tailings. Installation of WHIMS plant will enable recovery of substantial quantity of fines from tailings thereby reducing the quantity of tailings discharged to the environment by about 50%. As a result, the rate of inundation of forest land and consequent damage to trees may get reduced to a great extent. Besides, the life of the existing pond may be extended and construction of a new pond as well as encroachment/invasion on fresh forestland will get deferred substantially. Moreover, the size of the new pond will get reduced and thus the requirement of forest land are for tailings disposal will come down considerably. In view of the foregoing, WHIMS process may be considered as a positive environment management to save land space for tailing pond and also to recover the usable ore fines form tailings for recycling and reuse. claim 1. Process of recovering usable ores from iron ore tailings (having 45% Fe content) as resource for making cast iron comprises the steps of preparing tailing slurry in a balancing tank , subjecting them to 2-stage cycloning for the formation of a concentrated sample (having 58.9% Fe. 5.25% SiO2 and 5.51% Al2O3), separation of non-magnetic materials from the concentrated sample by subjecting them to Wet High Intensity Magnetic Separation (WHIMS) for further improving the ore quality ( having 64.00 % Fe, 2.75 % SiO2 and 2.20 % Al2O3 ) with 50% recovery from tailings, using the recovered fines with iron ore sinter feed for making of cast iron . 2. Process as claimed in claim 1, wherein tailing slurry (having 45% Fe content ) is prepared in a balancing tank and then subjecting them to a 2-stage cyclone separators to get the heavier iron ore concentrate at the underflow . 3. Process as claimed in claim 1, wherein a filter cake (concentrated sample) has been produced having 58.9% Fe, 5.25% SiO2 and 5.51% Al2O3 4. Process as claimed in claim 1 and 3, the filter cake is further subjected to a continuous type model WHIMS plant and the recovered ore fines from the tailings consisting of increased in iron concentration , but decreased in silica and alumina concentration ( improved the ore quality having 64.00 % Fe, 2.75 % SiO2 and 2.20 % Al2O3) with 50% recovery from tailings , which can be utilized as resource from tailings for cast iron making. 5. Process as claimed in claim 1, wherein the recovered ore fines are mixed with fresh iron ore sinter feed at different proportions, and the optimum proportion (up to 20%) is evaluated in which there is no adverse effect on the physical and metallurgical characteristics of the sinter Iron ore tailings contain iron concentration around 45%. In future it may become economically viable to extract iron content from tailings. But due to huge land cost and other environmental factors it is worthwhile to examine the feasibility to minimize the tailings volume. This research examines the feasibility of the recovery of resources from tailings and focuses on the reduction in tailings volume as part of environmental management strategy. A process has been developed and applied successfully in the Barsua iron ore mines of Orissa to solve its industrial problem . Adopting the process and with the use of Wet High Intensity Magnetic Separator (WHIMS) and it could be possible to improve the Fe content in the recovered ore from 45% to 64% and Al2O3 as well as SiO2 can be reduced to 2.20% and 2.75% respectively which can be utilized as resource for iron and steel making with 50% recovery from tailings. Thus a substantial amount, can be recovered as resource, which can be used as a sinter feed for making iron and steel It also reduces the tailing volume as well by adding those additional units to beneficiation plant. Sintering test was done with the recovered ore fines, which are mixed with fresh iron ore sinter feed at different proportions, tested and the optimum proportion (up to 20%) has been evaluated in which there would be no adverse effect on the physical and metallurgical characteristics of the sinter . This invention provides a sort of fundamental new scientific insight for the utilization of tailings as resource and environmental protection as well. The process developed has formed a guideline and can be utilized on an industrial scale for various sites

Documents:

9-kol-2005-abstract.pdf

9-kol-2005-claims.pdf

9-kol-2005-correspondence.pdf

9-kol-2005-description (complete).pdf

9-kol-2005-drawings.pdf

9-kol-2005-examination report.pdf

9-kol-2005-form 1.pdf

9-kol-2005-form 18.pdf

9-kol-2005-form 2.pdf

9-kol-2005-granted-abstract.pdf

9-kol-2005-granted-claims.pdf

9-kol-2005-granted-correspondence.pdf

9-kol-2005-granted-description (complete).pdf

9-kol-2005-granted-drawings.pdf

9-kol-2005-granted-examination report.pdf

9-kol-2005-granted-form 1.pdf

9-kol-2005-granted-form 18.pdf

9-kol-2005-granted-form 2.pdf

9-kol-2005-granted-reply to examination report.pdf

9-kol-2005-granted-specification.pdf

9-kol-2005-reply to examination report.pdf

9-kol-2005-specification.pdf