Search Documents

By Bisweswar Das, Barada Mishra, Hrushikesh Sahoo, Swagat Rath

Banded hematite jasper (BHJ) containing 45.2% Fe, 32.64% SiO2, 0.63 % Al2O3 and 1.25 % LOI is found difficult to beneficiate either by magnetic or flotation techniques due to fine intergrowth of jasper with hematite. Phase transformation by reduction roasting with activated charcoal followed by low intensity magnetic separation to achieve a suitable iron concentrate has been attempted in this study. The mineralogy of the ore and different roasted products has been studied by X-ray powder diffraction (XRD) and scanning electron microscope (SEM) to understand the reduction mechanism. The magnetite formation is observed at 850ºC while metallic iron appeared at a higher temperature. The effects of reduction variables such as reduction time (30-270 min), temperature (750-1050ºC), and reductant (1-12 %) using activated charcoal are studied. An iron concentrate with 64.65% Fe and 55.8% recovery could be obtained under optimum conditions of temperature: 850ºC, time: 1.5 h, and reductant: 6% by weight.

Jan 1, 2014

By Downing Terry L.

Dry mineral beneficiation methods have been developed for separation of borate minerals from montmorillonite claystone gangue. The methods include the use of newly developed dry high intensity magnetic separators. The application of these methods has the potential for economic benefit at U.S. Borax Inc. in three areas: ? Processing surface impoundments (ponds) material. ? Pre concentrating ore to be fed to primary refinery. ? Concentrating borate minerals to produce potential products.

Jan 1, 1995

By S. C. A. Franca, M. T. Millqvist, A. B. Luz

Laboratory experiments were performed on a Brazilian diatomite from Bahia State to produce an industrial product for use as a filter aid. Bench and pilot plant tests were conducted consisting of: diatomite desegregation, organic matter and clay removal, filtration, drying and calcination. Calcination temperature and sodium carbonate addition influenced diatomite particle size distribution. Optimum filtration rates for calcined products were obtained at 900°C and 47 min. residence time with 3% (w/w) of sodium carbonate addition, and resultant products met specifications imposed on filter aids.

Jan 1, 2002

By D. P. Chakraborty

Joda East Iron Mine, one of the captive iron ore sources of Tata steel, located in the state of Odisha in eastern India caters to approximately 45% of the iron ore requirement of the Jamshedpur Steel Plant. The iron ore occurring in the mine having high in iron content along with high in alumina. Clay and gibbsite are the predominant mineral phases present as surface coating, fracture filling and/or free occurring and are responsible for alumina content higher. Alumina in iron ore impacts the techno-economic performance of a steel plant by impacting sintering and blast furnace productivity. The impact is even higher when it comes to fine ore used in the blast furnaces in the form of sinter as it constitutes a major portion of the blast furnace burden. Therefore, it is beneficial to upgrade iron ore in the mine head and to reduce alumina before it is subjected to agglomeration. Mineralogical test works reveal, that alumina in iron fines is mainly associated with the clay attached to the hematite particles, either free or interlocked to a very fine size. The paper describes the efforts made to reduce alumina in the iron fines in Joda East processing plant, without much of capital investment for a very sophisticated fines beneficiation circuit. In this process, a suitable dispersant was added in the plant that dispersed the masked slime coating over the iron ore fines, thereby making a better quality iron ore fines with reduced alumina content. The alumina in fines improved by 0.2 units? means from a label of 2.4-2.6 % reduced to 2.2-2.4 %. With this initiative, not only the primary objective of alumina reduction is met but also it has given substantial benefit in reduction of silica and as well as moisture in product. This moisture reduction also has given bottom line impact by reducing idle freight and royalty.

Sep 1, 2012

By Surendra Kumar Biswal, Sachida Nanda Sahu, B. C. Meikap

The unutilized iron ore fines (IOF, − 10 mm, 45% to < 60% Fe(T)) left at various mine sites during blasting and processing are rich in goethetic-hematite associated with high clay and considered a potential iron ore resource. The variation of loss on ignition (LOI) from mines to mines is based on the goethite and clay mineral content. The clay containing below 45 μm is mostly brittle, causing beneficiation problems. The IOF has an LOI of 7.83%, with high silica (5.52%) and alumina (4.57%), and 57.17% of Fe(T) subjected to both conventional deep beneficiation (CDB) and magnetization roasting using high-ash non-coking coal to adopt the suitable upgradation process. The CDB and magnetization roasting concentrate has 62.61% and 67.58% Fe(T) with 64.69% and 85.19% yield, respectively. However, the presence of 6.40% LOI in CDB makes the ore challenging for pelletization. Characterization like X-ray diffraction(XRD), scanning electron microscope(SEM), and chemical analysis was used to assess the concentrate quality and potential industrial application.

Jun 4, 2022

Beneficiation of Coal Fines from Tailing Ponds of Tuntbilek Washing Plant

Sep 13, 2010

By Jing Zhou

In view of the state of the long time use of sodium cyanide in lead-zinc-sulfur-silver multimetallic ore production, we propose alternative reagents system through experimental research. The experiment first used TJ, sodium sulfide to adjust the flotation pulp, after that, zinc sulfate, sodium sulfite was added to low alkaline pulp to inhibiting zinc sulfur mineral and adapted MB, 25# aerofloat and diethyl dithiocarbamate combination collectors to float lead minerals. The obtained test index is as follows: lead concentrate recovery rate of small scale test was increased by 5 to 10%, the recovery rates of gold and silver in lead concentrate were increased by 7% and 11% respectively; the industrial test is conducted under the condition that the total grade of lead and zinc content in raw ore decreased by 4.81%, the total recovery rate of lead and zinc increased by 7%, recovery rates of gold and silver in lead concentrate were increased by 7.62% and 9.65% respectively. So it successfully realizes the target to replace the sodium cyanide, using low-alkaline non-toxic reagents system in mineral processing practice of three kinds of complex lead-zinc-sulfur ore of this mine. Keywords: refractory lead-zinc-sulfur ore, depressant, non-cyanide flotation

Sep 1, 2012

By Jean-Sébastien Kroll-Rabotin, Éric Climent, Florent Bourgeois

"Falcon concentrators are enhanced gravity separators designed for concentrating fine and ultrafine slurries. The Falcon UF model is unique in that it is dedicated to beneficiation of ultrafines, one key feature being that it does not make use of any fluidisation water. In a former study, we investigated the physical mechanisms that govern the transport of ultrafine particles (in the range 10 to 80 µm) inside Falcon UF concentrators, and concluded that separation efficiency is governed by differential settling. Initially, we derived and published a predictive model of the partition function under dilute conditions. The present paper proposes an extension of the initial model to concentrated ultrafine suspensions for application to industrial scenarios. The paper discusses how hindered settling has been added into the initial model to account for solid concentration effects. The modified model is tested against experiments carried out with a laboratory scale UF Falcon concentrator from dilute conditions up to 30 vol%. A good agreement between measurements and model predictions is obtained, which confirms that our hypotheses about the physics of separation inside a UF Falcon separator remain valid even at high concentrations.INTRODUCTIONThe Falcon concentrator is a fast spinning bowl that is fed at its centre of rotation. It uses centrifugal force to separate particles that are transported inside a thin liquid film that flows upward along the inclined wall of the bowl (McAlister and Armstrong, 1998). Due to differential settling, dense and coarse particles are concentrated inside the bowl whereas light and fine particles are rejected with the overflow stream. The fast rotation speed of the bowl yields high centrifugal force several hundred times the attraction of Earth. Despite the thinness of the liquid film (between 100 µm and 1 mm with a Falcon L40) where separation takes place, the Falcon concentrator can treat high flowrates (up to 30 L/min). At the bottom of the bowl, an impeller transmits the bowl rotation to the feed, which drains upward by centrifugal force as soon as it hits the base of the spinning bowl (Figure 1)."

Jan 1, 2011

By N. Acarkan

Slags usually contain some quantity of valuable metals. They are actually a secondary resource of metals, rather than an end-waste and have been utilized as a resource material in many areas. In addition, for some applications, slags have comparable or even better properties than their competitors. Leaching is a method for extraction of metals from copper slags. The extraction of metals such as copper and cobalt from the copper slag of Küre-Turkey, was investigated in the past decades. Fayalitic type of these copper slags containing 0.934 % Cu, 0.353 % Co and 50.91% Fe were subjected to the experimental study. As a result of mineralogical analysis of the slag sample, fayalitic type of slag was found to contain hercynite, magnetite, hematite, pyrite, chalcopyrite, covellite, bornite and metallic copper. Direct acid leaching methods were applied on the sample. Effects of leaching time, temperature and acid concentration on Cu and Co leaching recoveries were investigated in the direct acid leaching. The optimum leaching conditions were found as leaching time of 2 hours, solid/liquid ratio of 1/3, H2SO4 concentration of 125 g/L and temperature of 70 °C. At these conditions, 75.5 % of Cu, 95.6 % of Co and 70.9 % Fe were extracted. In the second stage of the leaching experiments, copper in the pregnant solution was precipitated by cementation to produce a Cu concentrate assaying 95.58 % Cu; cobalt was obtained by precipitation with H2S to produce a concentrate containing 62.10 % Co. As a result of this study a process flow sheet has been developed for recovering Cu and Co from these slags to demonstrate its economic and technological benefits.

Jan 1, 2014

By S. S. Hsieh

Bench-scale beneficiation studies were made on Idaho dolomitic phosphate rock using the TVA carbonate flotation process. The process employed diphosphonic acid as a phosphate mineral depressant and fatty acid as a carbonate mineral collector. Silica was subsequently rejected as float using an amine collector, with phosphate product recovered as the sink fraction. Two samples of prepared flotation feed from commercial operation were used; one contained 21% P205 and 3.2% MgO, and the other contained 26% P205 and 1.8% MgO. The results indicate that concentrates containing 31-33% P205 and 1% or less MgO can be obtained, with P205 recovery of about 80%.

Jan 1, 1984

By S. S. Hsieh, J. R. Lehr

Bench scale beneficiation studies were made on Idaho dolomitic phosphate rock using the TVA carbonate flotation process. The process used diphosphonic acid as a phosphate mineral depressant and fatty acid as a carbonate mineral collector. Silica was subsequently rejected as float using an amine collector, with phosphate product recovered as the sink fraction. Two samples of prepared flotation feed from commercial operation were used. One contained 21% P205 and 3.2% MgO. The other contained 26% P205 and 1.8% MgO. The results indicate that concentrates containing 31% to 33% P205 and 1% or less MgO can be obtained, with about 80% P205 recovery.

Jan 1, 1986

By Arthur F. Colombo

The selective - deslime - flotation process developed by the Federal Bureau of Mines as part of its goal of maintaining an adequate supply of minerals to meet national economic and strategic needs is described. The operating parameters for the selective flocculation - cationic flotation of oxidized taconites from the western Mesabi range in Minnesota are discussed. Data from the operation of a 410 kg/hr (900 lb/hr) pilot plant employing reclaimed water are summarized for 2 types of oxidized taconites.

Jan 1, 1979

By T. O. Llewellyn

The Bureau of Mines, U.S. Department of the Interior, conducted studies to recover phosphate from four dolomitic southern Florida deposits not currently mined. The samples contained 5.8 to 10.2 percent P205 and 1.7 to 1.8 percent MgO. Chemical analyses of sized fractions indicated that no pebble concentrate (plus 1.2 mm) could be produced from these samples. A scheme was developed that consisted of desliming, grinding, scrubbing, and redesliming the ore to produce a flotation feed. Conventional one-step fatty acid-fuel oil batch flotation tests on the samples resulted in concentrates containing 29.0 to 31.3 percent P205 at flotation recoveries ranging from 72.4 to 96.1 percent of the flotation feed. The MgO content of the concentrates ranged from 0.47 to 1.36 percent. Continuous flotation of the Manatee No. 2 sample indicated that commercial-grade phosphate concentrates analyzing 31.3 percent P205 and 0.55 percent MgO could be produced with a flotation recovery of 89.9 percent. The MgO content of concentrates obtained from the Manatee No. I and Hardee samples was 1.20 to 1.36 percent, respectively. Leaching with aqueous SO2 reduced the MgO content of these phosphate concentrates to 0.5 and 0.8 percent, but with a concomitant loss in phosphate recovery.

Jan 1, 1983

By M. Ghiani, R. Peretti, S. di Giovanni, G. Zonnedda, A. Serci, A. Zucca

"Beneficiation of the epithermal gold mineralizations associated with an extensive alteration zone in the Serrenti-Furtei region on the island of Sardinia, is proving a complex issue. Experimental investigations have in fact demonstrated that while the ores contained in the upper parts of the deposit are amenable to conventional cyanidation, the gold contained in the refractory ores in the lower portions needs to be recovered by means of flotation, combined with leaching where necessary.The results of commercial heap leaching, carbon-in-leach (CIL) processing and flotation, designed on the basis of the experimental findings and applied to the oxidized portions and transition zones of the deep sulphide mineralizations, confirmed the expectations emerging from the laboratory tests."

Jan 1, 2003

By S. C. Borah

Graphite, a mineral form of pure carbon, is one of the most versatile minerals in industry, because of its varying physical properties and characteristics. The mineral occurs naturally in the form of tubular crystals or microcrystalline earthy lumps, or it is disseminated in rocks, which have undergone intense metamorphism. India has a large deposition of graphite minerals out of which about 43% are found in Arunachal Pradesh. However, compared to the rest of the country, the North-East Region and particularly Arunachal Pradesh has not attracted attention till date for detail investigation for characterization, beneficiation, prospecting and/or exploitation of the mineral resources including graphite. Bulk graphite sample were collected from upper Subanshiri district of Arunachal Pradesh. Chemical analysis of the representative samples were carried out and found that 7.29%, 19.60% and 6.07% of fixed carbon (FC) is present in graphite sample collected from La-Lamdak, Bopi and Taliha, Arunachal Pradesh, respectively. Chemical analysis of the ash of the graphite sample shows presence of impurities such as silica, Al2O3, Fe2O3, Ca, Mg etc in the graphite sample which are also supported by XRD and SEM-EDX investigation. The graphite samples of Arunachal Pradesh are low grade and do not fulfill the market requirement for the industrial applications. Therefore, low-grade graphite is subjected to beneficiation for the upgradation of the graphite for industrial applications. We have adopted the dispersion?cum-settling technique for the beneficiation of the graphite sample collected from Arunachal Pradesh. The FC of 40.21% with 41.17% raw graphite recovery which is equivalent to 71.02% carbon recovery have been obtained by gravity separation technique using only distilled water without any chemical reagent in case of graphite sample collected from Bopi, Arunachal Pradesh. The graphite sample is upgraded up to 47.75% FC with 41.91% raw graphite recovery, which is equivalent to 85.85% carbon recovery with the pH adjustment at 9 with NaOH. Keywords: graphite, beneficiation, gravity separation, arunachal Pradesh

Sep 1, 2012

By Milind Chikhale, Ranjeev Kumar, Keshav Tyagi

Ore characterisation including mineralogy and beneficiation testwork of an ore is very important for determination of possible products and their quality. The results of such study help in ascertaining the beneficiation process route for the ore. The present study deals with ore characterisation study and beneficiation testwork on the samples of hematite iron ore with goethite impurity. The characterisation study reveals that the hematite is under alteration stage to goethite which has become an integral part of hematite. High goethite/limonite content is enhancing the loss of ignition content of the ore and reducing its Fe content. The findings indicate that in case of hematite iron ore associated with goethite and limonite, it is difficult to achieve high grade of concentrate above 65% Fe. It depends on the amount of goethite and limonite minerals and their association with hematite. These minerals contain aluminous impurities and hence, their rejection becomes essential. Separation of limonite and of goethite to limited extent is possible. In case of goethite, effective liberation is not achieved where it occurs as surface alteration product of hematite grains. The gangue mineral reported are clay and gibbsite, and are closely associated with iron minerals. The test work results indicate the grade and recovery of Fe along with alumina and silica content in lumps, sinter fines and pellet feed fines that can be achieved for the different ore types vis-a-vis the percent of available hematite in the ore. The recovery of iron is dependent on the hematite available and the loss of iron values in tailings is more because of rejection of limonite and goethite.

Jan 1, 2014

By Nidhi Kumari

This work is based on surface chemical properties of bacteria during adaptation to high grade copper minerals and the projected consequences in Bio-Flotation process. The utility of bio-processing in the beneficiation of copper ore through bio-flotation is demonstrated. An autotroph Acidithiobacillus Ferrooxidans bacterium is adapted to high grade mixed copper ore sample by repeated subcultures. The surface characteristics were studies by analyses at different pH and time intervals. From the studies, it was established that the mineral-adapted cells became more hydrophobic as compared to unadapted cells during bio-flotation. It was also noticed that there was no significant changes in the surface charge of bacteria before and after adaptation. Keywords: bio-flotation, copper, Acidithiobacillus ferrooxidans, hydrophobic

Sep 1, 2012

By T. Gouri Charan

Indian coals, which are of Gondwana origin, contain high amounts of mineral matter, wherein the extraneous material was intimately mixed in the coal matrix during the formation stage, causing a high level of impurity in the run-of-mine (ROM) material. These coals possess difficult to very difficult washability characteristics. Beneficiation of high-ash non-coking coals of India has become the prerequisite for improving the overall economics and efficiency of power generation. The use of dry cleaning systems in India for beneficiation of non-coking coals has gaining renewed interest recently. The benefit of the dry beneficiation process is to exploit the given resources while providing a more reliable and consistent quality fuel with a low operating cost. M/S Allmineral has introduced a technique for the dry beneficiation of coal, which is being tried in India for the treatment of high-ash non-coking coals. The first commercial air jig of 50 t/hr capacity was installed and commissioned to beneficiate high-ash coals of 40 x 5 mm feed with an ash content of 40%; a clean coal product of 33% ash was produced and is being used for a sponge iron plant.

Jan 1, 2011

By Arthur B. Johnson

The Bureau of Mines investigated the concentration characteristics of high-clay sylvinite ores from four potash companies operating in the Permian Basin near Carlsbad, N. Mex. These ores, containing 13 to 22 percent K20 and 3 to 7 percent clay slimes, cannot be effectively processed by current commercial flotation methods because of their high slime content. A solution to this problem was shown to be the use of two-stage moderate scrubbing conditions and washing of the ore as opposed to strenuous attritioning. Bench-scale physical beneficiation techniques for recovering potash minerals and the development of ore-dressing systems by flotation resulted in obtaining acceptable product grades and recoveries. By using a coarse grind, emphasis was placed on production of premium granular and coarse products. Flotation results showed that concentrates of 58.7 to 60.4 percent K20 with recoveries of 71.0 to 83.4 percent 0f the K20 values can be obtained.

Jan 1, 1971

By A. B. Johnson, J. S. Browning

The USBM has developed new and improved physical beneficiation techniques for economically recovering potash minerals from high-clay and low-grade ore from the Permian Basin of New Mexico. With the depletion of the high-grade ores a need for changes in industry&apos;s standard methods of recovery is a must. Technology may be improved in the beneficiation of the ore prior to mineral flotation and in brine clarification from the desliming phase to effect a reduction of losses of fine potash and brine in the disposal of the clay slimes. This report summarizes the results of these tests and demonstrates the feasibility of producing products that meet the requirements of the agriculture market, namely, 95% KCl equivalent to 60% K2O with recoveries ranging between 80 and 90%.

Jan 1, 1973