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By Kamalendu Bhunia

With the progressive depletion of known resources of good quality coal and minerals as well as the increasing demand of these minerals by different user industries, the emphasis has been shifted all over the world from selective mining to bulk mining followed by up- gradation to obtain the required quality of concentrate. The column flotation cell is one of the alternatives to reduce the gangue content of fines because of its inherent characteristics viz. easier to operate, low space required, no moving parts etc. A laboratory flotation column is used to conduct experiment. Present work has been undertaken to observe the effect of process variables (gas flow rate, feed/slurry flow rate, and frother concentration) on gas dispersion parameters (gas holdup, bubble surface area flux) in collection zone and to explore the effect of feed (slurry) inlet orientations and gas flow rate on column?s metallurgical performance. The effects of solid particle concentration, size and type (hydrophobic and hydrophilic) of solid on gas dispersion parameters have also been investigated. Test work has been performed in a continuously operating Perspex column (10 cm in diameter and 168 cm in height) using coal, sphalerite and dolomite as solid. Gas hold-up has been measured by phase separation method and mean bubble sizes are estimated from a drift flux analysis. The influence of operating parameters on bubble surface area flux has been discussed. It is observed that gas holdup in collection zone is affected by air as well as feed flow rates and also solid?s type. It is also found that addition of solid decreases the gas holdup and rate of decrease in gas holdup increases when solid concentration increases and particle size increases. Increase in gas flow rate increases recovery in collection zone due to increase in number of bubbles per unit volume of the column. From the experimental results it is evident that cross-current orientation of feed inlet shows slightly better metallurgical performance compared to other orientations. Keywords: column flotation, gas holdup, drifts flux, bubble size, bubble surface area flux, hydrophobicity, and recovery

Sep 1, 2012

By M. Roy

Coke combustion during sintering process is significantly governed by coke breeze size distribution, which in turn affect sinter quality i.e. sinter granulometry, Tumbler index, Reduction Degradation Index and Reducibility Index of sinter. To know the effect of microfines of coke breeze on sintering process parameters, pot sintering tests were conducted and it was found that when microfines are eliminated and optimum coke size (1-3mm) is used yield of sinter increased by more than 7%. Similarly productivity increased by 9%, the strength of sinter i.e. ISO Tumbler Index increased by 2.3% and +10mm sinter size increased by 5.5%. Controlling of microfines during crushing and by improving crushing index will result in improved quality and productivity of sinter with lesser amount of coke breeze. This paper describes that how to optimize solid fuel i.e. coke breeze consumption in sintering process through granulometry control. Keywords: iron ore sintering, coke breeze granulometry, productivity of sinter, quality of sinter

Sep 1, 2012

By E. P. Olberg, A. Yu. Chikin, S. V. Petrov, M. P. Belykh, N. L. Belkova

"Bacteria that grow in autochtonous communities of gold heap leaching (HL) wastes are adapted to high concentrations of contaminants and environmental conditions. An example of a mine in the Sakha (Yakutia) Republic showed that the bacterial factor had a significant influence on cyanide breakdown and copper and nickel removal in the conditions of HL ore pile zoning compared to chemical oxidation. The diversity of bacterial communities growing in natural and simulated conditions of a HL ore pile was determined for the purpose of the study. The identified bacterial communities included genus Achromobacter and Serratia, which were found to be adapted to a wide range of temperature and can be considered as potential microorganisms for detoxification of gold HL wastes. INTRODUCTION Technologies and systems of passive treatment are of a special interest in relation to solving environmental problems of gold HL wastes detoxification, when neutralization time is not considered as a limitation (Alvarez et al. 2005). Passive treatment methods are based on reagentless spontaneous breakdown of cyanide caused by natural factors, including activity of autochthonous bacterial communities. Implementation of a reagentless biodetoxification technology for mature HL operations provides reduction of environmental impact on industrial site locations and substantial economic benefits compared to conventional chemical processes of neutralization that prevail in the Russian Federation territory. Passive treatment of cyanide-containing wastes was investigated by M. Botz, T. Mudder, S.V. Petrov, L. Simovic, A. Smith, C.A. Young etc. However, the bacterial factor (autochtonous bacterial communities) role in this process is practically unexplored. Thus, the aims of the study included the investigation of a bacterial factor influence on passive treatment of gold HL wastes and the identification of functional groups of bacteria involved in passive treatment."

Jan 1, 2018

By P. Pourghahramani

Several structural characteristics change during intensive milling such as chemical composition, phase transformation, crystallite size, lattice strain, lattice parameter (s) and solid reactivity etc. The creation of defects enhances the stored energy (enthalpy) in the solids and consequently causes a decrease of activation barrier for the process and/or subsequent processes. In this paper, the effects of milling on the structural changes of hematite have been investigated using dry millings. The structural changes have been characterized using a combination analysis of BET surface area measurements and X-ray diffraction (XRD) analysis. Besides, the hydrogen reduction behaviors and kinetics of mechanically activated samples and initial sample were studied using simultaneous thermal analysis (STA). The methods of Williamson-Hall and Warren-Averbach were used for analyzing of XRD patterns to resolve and extract the microstructural characteristics of hematite phases. It was concluded that the breakage and aggregation of particles take place mainly in the starting and prolonged stages of dry grinding, respectively. The BET surface area enlarged steadily over the grinding processes whatever milling methods were utilized. The characterization of structural changes revealed that the hematite milled under various conditions did not undergo any significant reaction or phase transformation during milling processes. In addition, X-ray amorphous phase con-tent increased gradually with extending the grinding intensity. The maximum X-ray amorphous phase exceeds about 81% after 9 hours of milling in both tumbling mill and vibratory mill. The Williamson-Hall plots revealed the anisotropic character of line broadening for deformed hematite and changes in the trend of microstructural characteristics as a function of milling time. It was found that the surface weighted crystallite size decreases and lattice strain increases over the grinding periods. The minimum surface weighted crystallites were calculated about 17.3 nm, 12.2 nm for the products of tumbling and vibratory mills respectively. The maximum lattice strain,, in the grinding with tumbling and vibratory mills was calculated about 4.44×10-3 and 3.95×10-3respectively. 21/210nmLe=<> The non-isothermal kinetic analysis of the products revealed that Fe 2O3 reduced to Fe in a two-step process via Fe3O4. Intensive grinding resulted in improved resolution of overlapping reduction events. It was also established that the mechanical activation had a positive effect on the first step of reduction. The prereduction step in the activated samples initiated and completed at lower temperatures than that in non-activated samples. The activation energy of reduction decreased at the first step of reaction with increasing the grinding intensity. Intensive milling increased slightly the average activation energy of the second step of reduction due to the present of finely agglomerated particles and intensive sintering of the particles in higher temperature ranges.

Jan 1, 2014

By T. Saastamoinen, N. Heino

"The Olserum deposit located in Sweden hosts an indicated mineral resource of 4.5 million tonnes over 0.6 % TREO, exhibiting a relatively high proportion of HREE. Beneficiation of a composite drill core sample was studied in the flowsheet of magnetic separation of magnetite followed by REE minerals flotation. Primary testwork was performed to select an effective REE mineral collector and then the parameters of grinding size, collector and depressant dosages, slurry pH and density, conditioning time and temperature, and flotation time were tested for optimization of REE flotation. The studies of process mineralogy showed that the REE-bearing minerals monazite, xenotime and apatite were successfully enriched from the concentrations of 0.6%, 0.31% and 2.6% in the feed to those of 17.0%, 8.9% and 65.0% in the concentrate with the recoveries of 79.0%, 81.3% and 71.0%, respectively. INTRODUCTION The Olserum deposit located in Sweden comprises lower grade placer material with higher grade apatite-magnetite veins and hosts an indicated mineral resource of 4.5 million tonnes at 0.6% TREO, with 34% of that being HREO (EURARE, 2017). The mineralization was studied by Andersson et al. (2018). At early stage, high-temperature REE is characterized by abundant monazite-(Ce) and xenotime-(Y) coexisting with fluorapatite and subordinate amounts of (Y,REE,U,Fe)-(Nb,Ta) oxides. During a subsequent stage, allanite-(Ce) and ferriallanite-(Ce) formed locally, partly resulting from the breakdown of primary monazite-(Ce). Alteration of allanite-(Ce) or ferriallanite-(Ce) to bastnäsite-(Ce) and minor synchysite-(Ce) at lower temperatures represents the latest stage of REE mineral formation. The mineralogy and beneficiation were firstly studied by GTK Mintec in the EURARE project for a composite drill core sample. The Olserum is considerably smaller than the Norra Kärr deposit. However, REE are hosted by xenotime and monazite, both of which have well established processing pathways, and meanwhile, the Olserum has a high contribution of the high value critical REE (dysprosium (Dy), yttrium (Y), neodymium (Nd) and terbium (Tb)), which provide a unique advantage for its exploration (Tasman Metals Ltd., 2013). In this paper, flotation of the REE minerals in the Olserum ore was studied."

Jan 1, 2018

By M. J. Lottering

Gold deposits in South Africa are invariably associated with uranium bearing minerals. Although it is low grade uranium by international standards, averaging around 0.3 kg U3O8 per ton of ore, recovery of uranium as a by-product improves the overall economics of gold extraction. Moreover, the current high uranium prices as well as increased demand due to renewed interest in nuclear power provide significant incentives for dedicated uranium production. An understanding of the uranium leaching response to changes in operating conditions is an important first step to-wards optimisation of uranium recoveries. In South African acid leaching plants, uranium dissolutions higher than 90% are difficult to achieve, and the chemical origin of this limit is not clear. To study leaching behaviour, an important consideration is the mineralogical characteristics of the ores. Typically, a diagnostic leaching approach can be followed. In this paper, a mineralogy-leachability explanation is presented to rationalise the difficulty in exceeding 90% dissolution from low grade uranium ores on the basis of a simple diagnostic leaching method. It was found that brannerite was the main reason for the existence of a dissolution limit in Witwatersrand ore and that chemical liberation was more effective to increase end dissolution compared to physical liberation. The findings from these investigations will form guidelines for developing economically viable flow sheets for improved uranium recovery, at least in a South African (Witwatersrand) context.

Jan 1, 2014

By M. F. He

There are three polymorphic modifications in pyrrhotite (monoclinic, hexagonal and orthorhombic), with monoclinic and hexagonal polymorph being more abundant. The floatability of different crystalline structures of pyrrhotite (monoclinic and hexagonal) is studied in this paper. It is shown that the floatability difference of monoclinic and hexagonal is obvious and that the flotation recovery of monoclinic pyrrhotite is greater than that of hexagonal pyrrhotite using different collectors . Using butyl dithiophosphate as collector, the flotation recovery of pyrrhotite is higher than when sodium diethyl dithiocarbamate and sodium butyl xanthate are used as the collectors. Monoclinic and hexagonal pyrrhotites are more easily activated by Cu2+ in acidic conditions than in alkaline conditions, while Cu2+ can not activate hexagonal pyrrhotite when sodium diethyldithiocarbamate was used as the collector. By the measurement of contact angle, it is indicated that monoclinic and hex-agonal pyrrhotite float well and are easily activated by Cu2+when dithiophosphate was used as the collector. Using sodium diethyl dithiocarbamate as a collector, the flotation behavior of pyrrhotite was investigated. The relationship between potential and pH range for pyrrhotite flotation was established. The results show that the flotation of pyrrhotite is dependent on pulp potential at certain pH values.

Jan 1, 2014

By John O. Marsden

"Technology development and innovation has played a crucial role in the copper industry throughout history. The effective development and implementation of new technologies allows mankind to produce copper at progressively lower cost of production at a given feed grade and mineral type. This progress serves to counteract cost inflation/escalation over time and, depending on the magnitude of the cost benefit, allows ore cut off grades to be reduced thereby improving the availability, accessibility and utilization of resources. Two broad categories of technology development and innovation play a key role in this process: (i) incremental improvements and optimization of existing technology provide benefits in the near- to medium-term, and (ii) step change technologies provide value over the longer term. A key issue for potential developers and implementers of new step change technology is how to justify resource allocation and expenditures for such initiatives. This paper examines this issue with reference to specific case studies in the copper industry. INTRODUCTION AND BACKGROUND Technology development and innovation has played a crucial role in the commodity minerals industry throughout history, and none more important than the copper industry. As new, cost-efficient technologies are commercialized, the cost of production in real terms at a given ore feed grade and mineral type decreases. This progress enables ore cut off grades to be reduced allowing lower grade material to be processed economically, which in turn increases the availability and supply of the metal or mineral of interest. Cost inflation/escalation works in the opposite direction, squeezing margins for operations utilizing incumbent technology to process material from a given ore deposit. A prior review by the author considered the issue of technology development and sustainable competitive advantage. This review concluded that first movers and fast followers can achieve competitive advantage for periods of 10-15 years through effective deployment of new technologies (Marsden, 2004). A new, more comprehensive study and evaluation was completed in 2014. This paper presents a portion of the results from the 2014 study."

Jan 1, 2018

By H. Kasaini

Batch wise adsorption tests for platinum (Pt) on the surface of activated carbon pellets (Norit RO 0.8 BET surface area 1100 mg/g) were carried out in mixed chloride solution. The purpose of this study was to assess and compare the adsorption performance of amine-treated activated carbons (AACs) and native activated carbons (NACs) in terms of adsorption capacity and selectivity. The effect of pH and temperature on adsorption capacity and selectivity was established. The amine- treated ACs were prepared by anchoring the amino groups (butyl amines) on the surface of AC pellets in aqueous media and the UV-Vis was used to determine the amount of amine sequestered from solution by ACs. The dosage of butyl amine on the surface of ACs averaged 0.15 g/g, carbon. The adsorption mechanism was described by the ionization and complexation model whereby interaction between the protonated AAC surface and the anionic chlorocomplex ions (PtCl5 [H2O]-, PtCl62-) proceeded by either electrostatic attraction or/and by covalent bonding [(NH3)2PtCl6 or (CH2COO)2PtCl6]. By comparison, the adsorption capacities of Pt on amine-treated ACs and native ACs were 53.8 mg/g and 33.03 mg/g, respectively which highlight the benefits of anchoring functional molecules on ACs. The selectivity of AACs was influenced by solution pH. Pt adsorbed selectively on the surface of amine-treated ACs at pH<1.5. The highest separation factor that was recoded pertained to Pt and Fe species (ßPt/Fe = 90) then followed by Pt and Ni species (ßPt/Ni = 30) or Pt and Cu species (ßPt/Cu = 15). The lowest separation factor was recorded for Pt and Cr ions (ßPt/N= 5). Adsorption kinetics of Pt on amine-treated AC surfaces, according to the first and second order reactions, were investigated and results showed that rates were in the order 10= 5). -4 min-1 and 102 g?min/mg, respectively. The pseudo 1st order kinetics predicted the adsorption capacity of 51.81 mg/g which was almost similar to the experimental value (53.8 mg/g) while the second order rate equation predicted Pt adsorption capacity of 40.1 mg/g. Both The Langmuir and Toth isotherm fitted the Pt adsorption at pH < 1.0. The Freundlich isotherm tended to underestimate the adsorption capacity of AACs.

Jan 1, 2014

By Rhulani F. Maluleke, Francis W. Petersen, John H. Marsh, Johann de T. Steyl, Allan Nesbitt

"Pressure leaching of chalcopyrite and nickeliferrous pyrrotite at temperatures between 105 and 200 ºC has been proposed as a potentially viable route for the extraction of mineral elements from sulphide concentrates. In general, these concentrates contain iron, and the economic success of the processes is partially dependent on the choice of the environmentally acceptable iron-removal technique. One of the most widely used methods for the removal of iron from sulphate liquors is precipitation as hematite, goethite, or jarosite. The nature of the iron precipitate formed dictates downstream dewatering and residue treatment and disposal options. However, a better understanding of iron precipitation under the defined process conditions would consequently be of benefit in process design and optimisation.This study investigated the precipitation of iron in the autoclave at temperatures between 105 and 200 ºC. The effects of temperature, acid concentration, iron concentration, and the presence of other metal cations on the nature and composition of the precipitates were determined."

Jan 1, 2003

By X. Tan

In this paper, the application of the metallurgical residue produced from oceanic cobalt-rich crusts leaching process is studied in the area of wastewater treatment. The modification of the sulfuric acid leached residue and the adsorption behavior behaviour of heavy metal ions such as (Pb(II), Cu(II), Zn(II), Cd(II), Ni(II), Mn(II), Co(II), As(III)) in the waste-water on the surface of the residue are investigated. The rate of adsorption efficiency of heavy metal ions in the wastewater on the modified sulfuric acid leached residue is investigated. It is showed that when the initial pH value of wastewater containing heavy metal ions including Pb(II), Cu(II), Co(II), Ni(II), Mn(II), Zn(II), Cd(II) and As(III) range from 1.4 to 1.9, with the use of the modified leached residue, As(III) ion can be selectively separated from wastewater, and the separation efficiency can reach 90%~100%. The adsorption efficiency is affected by pH, reaction time, amount of adsorbent and the initial concentration of heavy metal ions in wastewater. The results showed that the optimum pH was natural pH value and the absorption equilibrium time was 2 hours. The adsorption efficiency of heavy metal ions increases with the addition of adsorbent and de- creases with the increase of the initial concentrations of heavy metal ions in wastewater. The heavy metal ions polluted wastewater, of which concentration is about 22.5~793.6 mg/L, can meet the national disposal standard for industrial wastewaters in China very well, after 2 hours treated by 3.75~7.50 g/L modified adsorbent at room temperature. Standard methods were used to investaged investigate the absorption behaviour between abosorbentabsorbent and metal ions in the wastewater. It is concluded that the adsorption behaviour of Co(II), Mn(II) and As(III) ion fits Freundlich iso-therm, while the adsorption behaviour of Pb(II), Cu(II), Zn(II), Cd(II) and Ni(II) ions fits Langmuir isotherm, and the saturated adsorption amount of the modified adsorbent is about 54.0~336.7mg metal/g?adsorbentabsorbent. It is suggested that the modified sulfuric acid leached residue produced from oceanic cobalt-rich crusts is environmentally attractive and meaningful as absorbent used in heavy metal ions polluted wastewater.

Jan 1, 2014

By Shobha Kumari

Coal is the prime source of energy in India. It now contributes to about 55% of the total power generation and will continue to have its major share in the energy mix of the country in the foreseeable future. Thermal coals of India, known for their wide variations in nature and categorized as difficult to wash due to their typical mineral matter association with the organic matrix, need suitable beneficiation technique for quality upgrade for improving the overall economics, efficiency and pollution free power generation. A non-coking high-ash coal, collected from Vasundhara open cast mine of the Ib Valley Coalfield, Orissa, has been characterized along with its different fractions obtained in the process of beneficiation for distribution of minerals using FTIR, XRD and ash analysis. The raw coal was fractionated by size as well as by density. It has been observed that ash yields and mineralogical composition (found to be mainly kaolinite and quartz) have no appreciable change in different size fractions, indicating homogeneous distribution of minerals in the coal matrix. However, for the different density fractions the mineral composition and ash yield have significant variations. The quartz content of the beneficiated coal visualized with 34% ash yield, as mandated by the Ministry of Environment and Forest (MOEF) for the use of coal in power plants is reduced to half of that of the raw coal. As quartz is the most abrasive mineral in coal, reduction of its proportion obviously signifies considerable reduction of wear of power plant machinery when beneficiated coal is fed to utility boiler for generation of power. The composition of the major minerals quartz and kaolinite as determined, also favors formation of ash of refractory nature during combustion. Keywords: IB valley coal, beneficiation characteristics,

Sep 1, 2012

By V. A. Chanturiya

In Pt- and Au-keeping complex ores processing, about 10% ~ 15% of noble metals are lost with true tailings that are due to low floatability of Pt- and Au-keeping minerals by the conventional collectors. With the aim to achieve the effective recovery of noble metals at flotation of Pt-Cu-Ni and Au-keeping ores organic complex reagents keeping electron-donating atoms of nitrogen, oxygen, sulfur or phosphorus may be offered as selective collectors for the indicated minerals. These rea-gents tend to form complex compounds with PGM. Besides this, Cu-Ni-Pt and complex Pt and Au carbonated mica ores are characterized by finely disseminated (up to nanometer size) mineral forms of Pt in multivalent states. In this connection, the use of a combination of the strong ionic collectors with nonionic reactants that are capable to derivate complex compounds with multivalent PGM seems to be expedient for this type of ores. In the research new complex reactants were tested such as cyclic alkylene-trithiocarbonates, oxyalkyl butylxanthogen acid ethers, a combination of the collectors ? mercaptobenzothiazole (MBT) and dialkyldithiophosphates (DTP). Sorption and flotation tests were made with monomine-ralic samples of chalcopyrite, pentlandite, pyrrhotite, pyrite, and Pt-Cu-Ni sulfide ore samples. Sorption properties were examined by the extractive UV spectrophotometric method and potentiometric measurements. To indicate a structure of modified xanthate solutions the method of a thin-layer chromatography (TLC) was applied. The chromatographic behavior of the basic components of modified xanthate solution ? ButX, cyclic propylene-trithiocarbonate (PTTC), diethyl-dithiocarbamate (DEDC) and the product of its modification ? oxypropyl-S-ether of dithiocarbamatic acid was studied on plates ?Silufol UV ? 254?. The composition of organic solvents and its ratio in a mobile phase was deter-mined for simultaneous chromatography of the main components of a reaction mixture. It was found that operating selectivity of MBT, DTP and cyclic alkylene-trithiocarbonates incorporated in modified xanthate in relation to Pt-Cu-Ni and Au-containing sulfide minerals might be explained by an electoral sorption of this nonionic collector on a surface of the minerals studied. It was demonstrated that the application new reagent modes with the use of a combination of designed complex reactants helped to increase the extraction index of Pt- and Au-keeping minerals from complicated ores.

Jan 1, 2014

By G. Prabhulingaiah, D. M. R. Sekhar

"A phosphate deposit of estimated 6 billion tons of P2O5 is located 180 to 300 meters below the sea level, 185 kilometers north of port Luderitz, Namibia. The ore bed is 6 kilometers wide and 220 kilometers long. The ore deposit analyzing 16% P2O5 is loose sediment of 1.5 meters thick without over burden. Sizing of the ore to - 1.4 mm + 0.150 mm improves the grade to 23.54% P2O5 with a P2O5 recovery at 83.75% containing phosphate pellets and flakes of sea shells. Clay, bacterial debris as organic matter, flakes of broken sea shells and fine phosphate containing particles report to - 0.150 mm fraction and + 1.4 mm fraction contains sea shells and few phosphate containing pellets. The mineralogical composition of phosphate containing pellets is estimated (Droste, T.C., 2004) 80% frankolite, 6% pyrite, 4% illite, 3% quartz, 3% amorphous SiO2, 1% carbonates, 1% organic carbon and = 1% ilmenite, magnetite, zircon etc. The phosphate content in the pellets is around 27.7% P2O5. Trials to separate by gravity or flotation processes were not successful. Leaching of carbonates (sea shell flakes) under mild acidic condition (= 2% acetic acid or HCl solutions) or calcinations followed by leaching however yielded residues (concentrates) of grades 27.85 - 32.74% P2O5 at P2O5 recoveries ranging from 78.45 - 96.8% P2O5."

Jan 1, 2014

By Susanna G. de Jager, Francis W. Petersen

"The aim of the project was to develop a methodology applicable to different South African coal types to be able to predict with a high degree of certainty what kind of reagent will be suitable for flotation of a certain coal type.The study included 5 coal samples from different collieries and included Highveld seam 3 and 4 coal (as one sample), Waterberg coal (zone 10 -11), Highveld seam 5 upper coal and Witbank seam 2 and seam 4 coal. Seam 3 and 4 (mixture) coal, Waterberg and the seam 5 upper coal were all found to be vitrinite rich coals. The coal characterisation study included petrographic analysis, proximate analysis, float-sink analysis, oxygen-containing functional groups, surface extraction, flotation release analysis and contact angle measurements.The flotation tests showed that the best reagents to float all of the coal samples studied are iso-decanol and dodecene. These reagents produced flotation products that are near to the release curve. Statistical relationship for predicting ash content and yield that can be expected for a certain coal type and selected collector was obtained. From the relationship, the accuracy of the yield is above 95% (p-value below 0.05) with a linear regression of 0.9289. The accuracy of the ash is slightly lower with a linear regression of 0.7841 but also above 95%."

Jan 1, 2003

By O. Martinsson

The Kiruna area is an important mining province in northern Sweden, which is dominated by Fe- and Cu-Au deposits. Economically most important for the region, are the apatite iron ores with an annual production of c. 43 M ton of crude Fe-ore and a total production of more than 2000 M ton of ore the last 100 years. The apatite iron ores in the Kiruna area are dominated by either Magnetite or Haematite and contain varying amounts of apatite giving them a content of Fe and P, which varies between 30-70 % and 0.05-5 %, respectively. A typical geochemical feature of the ores is the strong enrichment of REE that is caused by a high content of REE in apatite and the occurrence of Allanite and Monazite containing 22.4 and 69.8 wt% REO, respectively. At Kiirunavaara, the content of REE in apatite varies between 0.07 to 1.57 wt% REO with a dominance for the light rare earths. The variation in REE-content of apatite depending on textural and paragenetic aspects is not known but apatite grains may display a strong LREE-depletion due to hydrothermal alteration. Monazite occurs as rod-shaped or tabular inclusions in apatite and is suggested, to have formed in response to hydrothermal alteration of apatite after the emplacement of the ore. Inclusions are mainly found in the central part of apatite grains occurring in veins and schliren, while they are rare in apatite occurring disseminated in the ore. Monazite also occurs as larger grains outside apatite and together with Allanite is found in texturally and paragenetically different settings within the ore. These occurrences of REE-minerals may largely be a product of LREE mobilized by alteration of apatite after the emplacement of the ore. However, REE-minerals including Allanite and Monazite might also have formed directly from late magmatic fluids. Keywords: apatite, monazite, allanite, ree, kiirunavaara, iron ore of kiruna type, mineral chemistry

Sep 1, 2012

By M. Rudolph, E. Schach, M. Buchmann, T. Leißner, N. Krupko, U. Peuker, M. Kern

"In mineral processing, density and magnetic susceptibility are two very fundamental properties. For the beneficiation of valuables to produce a saleable concentrate a detailed understanding of these properties is essential. Especially when it comes to the processing of cassiterite, which is the main mineral for tin production, they become highly prominent. Due to the chemically inert character of cassiterite towards most industrial applied leaching agents, density and magnetic separation processes are mainly applied for its beneficiation. To guarantee an optimized utilization of the different operations not only cassiterite but also the different gangue minerals have to be considered. In this study, a skarn ore is characterized by density and magnetic susceptibility. Therefore, the material was first split into different density classes by heavy liquid separation. The obtained classes were further separated by their susceptibility to finally obtain a density-susceptibility matrix. For this purpose, an isodynamic separator was used. A more detailed characterization of the materials is done via gas pycnometer, magnetic susceptibility balance and vibrating sample magnetometer to estimate the characteristics of density and susceptibility for the various classes. Further, the determination of the chemical assay and the mineral intergrowth by mineral liberation analysis is used to generate a three dimensional database for detailed characterization of the present ore. The objective of this study is to estimate potential material streams for a modular processing plant via characterization of the material for the entire deposit by the two afore mentioned characteristic properties. The established multidimensional data matrix, enables predictions for the separation properties of the material and contributes to the characterization of the deposit within the context of geometallurgy."

Jan 1, 2018

By D. H. Xiong

Low grade oxidized iron ores are usually not economic to utilize. However, the development of SLon magnetic separators and other new technologies make the process cost lower and lower. In this paper, several low-grade oxidized iron ore process flowsheets are introduced. The key procedure is that at the early stage, SLon magnetic separators are applied to discharge as more tails as possible with very low cost, only a small portion of rough concentrate going to the cleaning stage, showing the new technologies are profitable for such iron ores.

Jan 1, 2014

The characteristics of mineral resources and tailings resources in China are analyzed. Those tailings, which have double characteristics, can occupy land, pollute environment and even influence human habitat if they are not disposed in time. So pay attention to the comprehensive utilization of the tailing more and more both at home and abroad. The present situation and problems in comprehensive utilization of iron tailings in China are introduced by combine some practice experience, and have looked forward to the comprehensive utilization of iron tailing situation.

Jan 1, 2014

By Jun Xiao, Jianwen Yang, Yanhong Dong, Daixiong Chen

"MANGOTE Surface oxidizied mine is a gold-bearing deposit in Congo's Mai-Ndombe Province. In the past decades, the ore has been exploited in a crude way by local farmers, which directly causes the severe processing difficulty and lack of economy of cyanide leaching. Hunan Research Institute for Non-ferrous metals (HRIM) is currently investigating options to recover gold through understanding the mineralogical characteristics of MANGOTE surface oxidized ore. Chemical analysis , X-ray diffraction(XRD) and Quantitative Evaluation of Minerals by SCANing electron microscopy (QEMSCAN ) were conducted on samples from mine site. The bulk analysis results showed that gold separation of gold from gangue minerals was feasible after grinding the ore samples to 86.53% -74µm and adjusting the pulp specific weight at 100g/L, and gravity separation was conducted with using spiral chute after grading of fine particles. The research results highlight relationship between mineralogical characteristics of abandoned ore and economy of comprehensive utilization that might be directive experience to similar cases. INTRODUCTION The occurrence state of gold in natural gold minerals determines the basic recovery and recovery effect of gold(Komnitsas, C., & Pooley, F. D. 1989). The occurrence of gold in the ore refers to the form of gold in the ore.Generally the existing state of gold can be divided into four major categories according to the viewpoint of the dispersion system: independent minerals and gold, a coarse dispersed system;colloidal gold, a colloidal dispersion; solid solution gold, is atomic ion dispersion; adsorptive gold, according to the adsorbed particle is the micelle or ion, respectively is a colloidal dispersion or ion dispersion(Mao, S. D., & Yang, R. S. 2009; Liu, J. J. et al. 2007; Horisberger, M., & Rosset, J. 1977; Li, Y., & Audétat, A. 2013).With the increasing technology of comprehensive utilization of resources,varied plants can now process different gold ores with various occurrence states(Neesse, T. 2014; 7. Ogundare. et al.2014)."

Jan 1, 2018