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By M. Y. Zhou

The paper elaborates on the significance of producing ultra-low-moisture ore concentrate, the operating principle and technical features of thermocompression- filtration process, the kinetics involved in the dewatering process, and the technological process system and equipment used. It is pointed out that it is possible to reduce the moisture of fine ore concentrate to a minimum. By way of example, the case of the treatment of flotation molybdenum (Mo) using the thermocompression- filtration process is cited.

Jan 1, 2014

This article takes the OMRON C200HE PLC for example introducing its application in mica-paper production equipment, including style selection, address assignment of I/O point, and programming for different function. In the transformation process of simulated data and digit data, the corresponding relations between two data and so on are also discussed.

Jan 1, 2014

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 Lev Filippov, Vyacheslav Severov, Inna Filippova

"Reverse cationic flotation is a very efficient method of beneficiation of oxidized iron ores when you need to separate hematite and quartz. This method can be also applied to reduce silica content in the magnetite concentrates obtained by wet low-intensity magnetic separation. However, cationic flotation in this case is less effective due to the presence of Fe-Mg-Al-bearing silicates as amphiboles in magnetite ores. These silicates are concentrated in magnetic products and determine the difficulties of their separation from iron oxides when amines and starches are used as collectors and depressants, respectively. The recalculation of the results of the electron microprobe analysis of three calcic Fe-Mg-Al-bearing amphiboles used to characterize cation distributions in structural units and to obtain structural formulas in accord with stoichiometric limits was conducted. The Mössbauer spectroscopy was used to examine the validity of the empirical estimation of cation distributions in amphiboles. The studied samples are metamorphic pargasite and ferrotschermakite and volcanic magnesiohornblende. The crystallographic analyses of the amphibole samples exhibited their heterogeneous surfaces explaining worse floatability of amphiboles with dodecylamine at pH 10. The electrokinetic measurements showed that the position of the isoelectric point of amphiboles is related to a substitution of Al3+ for Si4+ in tetrahedral sites and to an amount of Mg2+ cations in octahedral sites. Thus, the dodecylamine adsorption onto amphiboles through electrostatic interactions is mainly affected by a distribution of these cations in tetrahedral and octahedral sites of amphiboles. In addition, the effect of starch on the depression of Fe-Mg-Al-bearing amphiboles during flotation can be attributed to the presence of metal ions on the amphibole surface, which are capable of forming strong chemical complexes with starch molecules."

Jan 1, 2014

By D. Moradkhani

The objective of this research was, to evaluate the hazard of heavy metals in the soil around the National Iranian Lead & Zinc (NILZ) Company. In this study, 38 samples of soil around the NILZ factory were collected using standard sampling method, so that, the heavy metals Pb, Zn, Cd and Cr have been evaluated. The concentration of heavy metals were measured and compared with standard limits. The results show that the hazard of heavy metals in soil is not so serious and the content of Pb in just 5 percent of samples, and the content of Zn in just 3 percent of samples were above standard limits and the concentration of Cd and Cr were under the standard limits. Average, variance and standard deviation of the elements are calculated and with due attention to the standard deviation, Pb and Zn are seen to be more distributed than Cd and Cr. Also the isograde curve of heavy metals was drawn using software called Surfer. These curves showed that the heavy metals are concentrated at particular distances from the factory. Keywords: heavy metals, remote sensing, sampling method, isograde curve, Surfer software

Sep 1, 2012

By Q. Zhang

Phosphate tailings through Flotation contains large amount of dolomite which is difficult to be separated from apatite. In this present research, phosphate tailings is recycled by Flotation i.e. re-processing. High-purity dolomite with purity as high as 91.17% is seperated, which contains 19.82% of MgO. The results of orthogonal test show that the effect of various levels of different factors on the high-purity dolomite floatated. Future utilization of purified dolomite is also discussed: magnesium fertiliser especially magnesium phosphate is expected to be an ideal product from high-purity dolomite.

Jan 1, 2014

By T. Kumaresan

The Bayer process used for refining bauxite to smelting grade Alumina serves as the linchpin of the Aluminum production industry worldwide. Even though the process is well established, the presence of impurities in the liquor affects the quality of product and imposes a major economic cost on the industry. This review article focuses on the issues pertaining to Gibbsitic (Al2O3.3H2O) precipitation circuit. The comprehensive review provides a basic understanding of the aluminum trihydrate precipitation and agglomeration phenomena. Crystal growth rate and agglomeration play a significant role in determining the output PSD of agglomerates. Hence, the effect of certain thermodynamic and hydrodynamic parameters along with the impact of impurities (oxalates, aldols, acids etc.) and additives on hydrate growth has been reviewed.

Sep 1, 2012

By Xin Tan

In this paper, two types of low-grade complex zinc oxide ores (sandstone and limestone ores) from Yunnan province, China were investigated. A large number of argillaceous and alkaline gangue makes it infeasible to treat the ores with heap leaching. Although wet metallurgy can be considered, the lower efficiency of liquid-solid separation, the high cost, and low revenue limit this technology to be put into practice in large-scale. In order to solve this problem, a new technology combining mineral processing method with metallurgy technique is studied to process this refractory ore that consists of sandstone ore with 5.84 per centZn and limestone ore with 6.50 per centZn. The results of the tests showed that zinc can effectively be recovered from two types of the ores by using the new technology, and the acid consumption can be remarkably reduced. For sandstone sample, 82.96 per cent Zn was recovered by flotation and final Zn recovery by flotation+ hydro-metallurgy can be up to 78.17 per cent from the ore. In addition, for sandstone, acid consumption can be reduced from 270kg/t by direct acid, leaching to 76.92kg/t by flotation + hydrometallurgy combination. For limestone sample, 85.90 per centZn was recovered by flotation and totally 80.95 per cent Zn can be recovered by new technology which is a combination of mineral processing and metallurgy. Besides, H2SO4 consumption can be reduced from 450kg/t for sandstone originally to113.79kg/t after using new technology. One merit of this new process technology is that the zinc sulfides and oxides can be recovered without desliming in the flotation cells at the different stage and make sure the concentrate products as a good feed for hydrometallurgical technology. This study provided pretty good technical support for tapping low-grade refractory zinc oxide ores. Keywords: low-grade zinc oxide ores, limonite, non-desliming beneficiation, flotation + hydrometallurgy combination

Sep 1, 2012

By F. M. Zafar Kaifi

Magnesite producing companies rely on high grade purity MgO. The mineralogy of magnesite has a significant impact on the manufacturing of magnesite bricks. The manufacturing process of bricks companies utilizes 90% magnesite from 85%~90% MgO. The main objective of the magnesite bricks was to utilizes the indigenous raw material available in bulk quantity. With better under-standing of chemistry of the mineral species and strict control of bricks manufacturing/processing conditions can be better produce efficiently, a low cost high quality bricks with minimum detrimental environmental impact.

Jan 1, 2014

By D. Y. Liang

Rare metal ores have those features of high industrial value and bad performance in ore separation. Most of rare metals ores are with low grade of valuable components, rareness of useful minerals, complicated combination of associated minerals and high difficulty in separation and enrichment of minerals. For those single (Ta, Nb) or (Ta, Nb, Sn) ore occurred in granite and pegmatite, the ways of gravity separation and magneto electric separation to concentrate (Ta, Nb) minerals are adopted. There are many mines being explored successfully both at home and aboard. While, for complex (Nb-Zr-REE) ores associated with Be and Ti minerals, they are commonly considered as rich rare metals ore but more difficult to process. One of rare metals mine in Inner Mongolia has the features as with large reserves and high grade of columbium and zirconium and accompanies with REE and beryllium, therefore with significant industrial value. After the utilization of research method of process mineralogy, detailed mineralogy research has been made on the rare metals ore. The test results show that there are abroad isomorphism replacements among such elements, such as Ti, Mn, Fe, Nb and Ta, between Be and REE in metallic oxide minerals of that ore, which makes the mineral composition of that ore extremely complicated. This research identifies clearly the mineral composition, and investigate at the technological property and the occurrence of those elements as Nb, Zr, Be and REE in the rare metal ore. The achievements of this research provide important mineralogy basis for ore dressing research of refractory rare metallic ores.

Jan 1, 2014

By K. Gonçalves

One of Vale?s sponsored research project is aimed at the implementation of a practical scale-up procedure for flotation. In this context, detailed flotation kinetics characterization is of critical importance. This work presents the results of a campaign aimed at characterizing flotation kinetic parameters with respect to particle composition. MLA analysis was carried out for 40 narrow-sized iron ore particles with known flotation time from a controlled flotation kinetic test. The iron ore sample studied (59% hematite and 41% quartz) comes from a mine in the southeast of Brazil and the type of reagents applied are the same as used in the plant. For the reagent conditions tested, the overall rougher concentrate (sink) yielded 79.1%, pure quartz and hematite recoveries to the froth were 56.0% and 4.8%, respectively. The results from the kinetic tests show that the flotation rate of the particles doesn?t vary much (~0.03s-1) with composition and that the fraction of floatable particles in each grade controls the separation action. The results show that the rate of flotation is controlled by transport and that the selectivity is controlled by the fraction of floatable particle of each phase.

Sep 1, 2012

By I. A. Khabarova

The paper presents the results of experimental investigations of the effect by high-power nano-second electromagnetic pulses (HPEMP) on change of surface composition, physical-chemical and flotation properties of pyrrhotite, and search of optimal combination of flotation reactants providing increase of metal extraction from disseminated copper-nickel ores. Preliminary electropulse effect on products before flotation allows to create optimal conditions for flotation separation of pentlandite and pyrrhotite owing to forming the new phases and defects on the surface of sulphides. It was established, that the yield of monomineral fractions of pyrite, pyrrhotite and chalkopyrite increases by 5%~15 %, compared with flotation with one butyl xanthenes (BX), during usage of combination of thionic carbamate (isopropylmethylthionocarbamate (ITC) or isopropylethyl- thionocarbamate (Z-200) with butyl xanthate (BX). Sorption of investigated reactants and strength of their fixing on the surface of minerals are examined; it helped to reveal the cause of rise of floatability of sulphide minerals for the case of combination of reactants. Preliminary high-pulse processing and reactant conditions with usage of combination of thionic carbamate and xanthate have been tested on the sample of disseminated copper-nickel ore from Norilsk region.

Jan 1, 2014

By M. D. Amirova

Cyanide-free technology of complex copper-lead ores flotation may be improved through enlarged range of pH values, enhanced copper recovery into copper concentrates due to additional recovery of secondary copper sulfides, as well as through enhanced efficiency of lead sulfides depression in process of new flotation modifiers-based selective separation. Study of the effects of flotation modifier (of metal nature) on minerals surface conditions proved that the xanthate is practically not adsorbed on the galenite surfaces due to minerals hydrophilization. Joint effects of sodium sulfite and modifier enhance process conditions for intensive galenite depression and at the same time for effective chalcopyrite and chalcosine flotation within a large pH values range (from pH=8 to pH=10). Identified mechanisms carry inference that proposed chemical reagent treating method is very promising for selective copper-lead concentrates separation. Potential use of carbon-containing materials as zinc flotation modifier to enhancing zinc recovery in processes of lead-zinc ores treatment has been studied. In our flotation tests we used Shalkiya (South Kazakhstan) lead-zinc ores containing such impurities as carbon shales, which presence impedes the process of saleable concentrates production and gives rise to excessive consumption of flotation agents due to the xanthate adsorption on the carbon. Lead and zinc concentrates were produced by process stages as follows: ores milled to 95% Cl. -0.074 +0; lead and zinc roughing flotation and further recleaner and testing operations. Test flotation in open process cycle resulted in enhancing zinc recovery into zinc concentrates by 21.1% and increasing zinc content in zinc concentrates by 3.96% that evidences promising potentialities for use of carbon-containing products as additional zinc flotation modifier. Works were carried out under National Program 2003~2005 of fundamental researches ?Physical and Chemical Mechanisms of Interactions in Multicomponent Solid and Liquid Systems Specific for Integrated Processing of Complex Metal-Containing Minerals and Technogenic Raw Materials? and contractual Agreement 2005 Optimization of Production and Technology of Shalkiya Lead-Zinc Ores Processing at Kentau Dressing Works.

Jan 1, 2014

By X. J. Lu

Purified Na-montmorillonite samples were used as the starting materials to prepare organically modified montmorillonites (OM), and a series of OM samples were prepared by intercalation of al-kyl quaternary ammoniums with different alkyl chain length. The interlayer spacing (d001) of the OM was determined by small angle X-ray diffraction and its gelating performance was characterized by measuring the viscosity of OM/dimethylbenzene mixture. The effects of alkyl chain length, dosage of alkyl ammonium, intercalation duration and layer charge of the starting material on the OM structure and gelating properties were investigated. According to the results, the adsorption quantity of the alkyl ammonium is dependent on the hydrocarbon chain length, the dosage of the alkyl ammonium and the retention time. The adsorption quantity of the alkyl ammonium increases with the chain length and the dosage, and extra adsorption more than the CEC of the montmorillonite sample was observed under the dosages of more than 1.3 CEC. The interlayer spacing (d001) of the OM shows a dynamic variation with the dosage and the retention time, and super interlayer spacings greater than the length of the alkyl ammonium were observed under larger dosages and shorter retention times. However, the gelating performance of OM does not follow the variations of the adsorption quantity of alkyl ammonium, an optimum viscosity value of OM/ dimethylbenzene gel was observed with the moderate adsorption of the alkyl ammoniums. Furthermore, the layer charge plays an important role on the gelating performance of OM. The OM synthesized by the starting material with lower layer charge shows better gelating performance in the dimethylbenzene solution.

Jan 1, 2014

By X. S. Yuan

With a demand for increasing energy efficiency and a need for improving bitumen recovery, a highly integrated solution for sustainable lease development of Aurora North of Syncrude has been proposed and implementation plans are underway. Flocculation and thickening technology as an important component of the integrated solution provides Syncrude an opportunity of rapid heat recovery from tailings and more flexible tailings closure and reclamation options. Flocculation of fine-particle suspensions by polymers is a non-equilibrium process whose performance is strongly influenced by physical and chemical variables. While polymeric flocculants are frequently used to establish the chemical conditions favorable for flocculation, the actual performance of a flocculation process generally depends more on the physical variables, such as the hydrodynamic conditions in mixing the flocculants and slurry. In order to study the effect of hydrodynamic conditions on flocculation of Syncrude fine tailings, a standardized laboratory test procedure called power flocculation has been developed in comparison with the conventional manual mixing methods. It is shown that the agitation speed and time in conditioning the flocculant solution and the slurry have a profound effect on the flocculation performances measured by initial settling rates, supernatant clarity and sediment density. It was found that the optimum bench test conditions for power flocculation of Aurora fine tailings with a sand-to-fine ratio (SFR) of about 1:1 are conditioning of the flocculant solution and the tailings slurry at 250 rev/min to 300 rev/min in 20 s to 40 s. The test results are inter-preted with a flocculant adsorption/redistribution kinetic model that helps understanding of the effect of hydrodynamic conditions on flocculant adsorption, floc formation and floc growth.

Jan 1, 2014

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 Gulsen Tozsin, Ekrem Kalkan, Taskin Oztas, Elif Agirman Akturk, Ercument Koc, Ali Ihsan Arol

Marble wastes are generated by quarries (marble quarry waste-MQW) and processing plants (marble cutting waste-MCW). The large amount of marble wastes is becoming serious problem for industry and environment because of discarded into rivers and lagoons, without any treatment. Marble wastes can cause environmental problem and economic loss if the waste is not used. However, this type of wastes has a good potential to be used as an amendment for the neutralization of acid soils. In this study, MQW and MCW were applied to an acid soil at different rates and their effectiveness on neutralization was evaluated by a laboratory incubation test. The results showed that soil pH increased from 4.71 to 6.36 and 6.84 by applications of MCW and MQW, respectively. It was suggested that MQW and MCW could be used as soil amendments for the neutralization of acid soils, and thus the negative impact of marble wastes on the environment could be reduced.

Jan 1, 2014

By Yi Ran Zhang, Nawoong Yoon, Brent Hilscher, Maria Holuszko

"Ore sorting technology has been rapidly advancing in recent years. Improving expected mill feed grade has a significant benefit to project returns, and can no longer be ignored. When there is an increase in the mill feed grade while maintaining the same throughput, the mine will be able to process much more metal and improve the floatation recovery. There are many more factors that contribute toward the economics of the project by implementing sensor-based sorting technologies covered in this paper. This paper reviews the economic impact on an underground copper-silver deposit with references to the concept of ""profit recovery,"" which is the measurement of recovery based on rock profitability rather than just metal content. The economic impact of sensor-based sorting is discussed in detail throughout the paper. The preliminary economic evaluation of the project compares the mine's base case design versus a design incorporating sensor-based sorting. The paper's primary focus is on economic impacts rather than the explanation of the sensor based sorting results. The sorting data is presented on a scoping level and using a sensor-based sorting study where the best possible results are used for obtaining the grade recovery curves. Also, the breakdown and analysis of the project economics are based on the operating cost available from the particular operation. Any assumptions taken into consideration are also outlined and discussed. INTRODUCTION The mining industry has been adopting Sensor-based ore sorting technology fairly rapidly in the recent years. The ability to increase mill feed grade by rejecting waste grade rocks early in the processing stage is proving to be revolutionary for some operations. These potential outcomes should not be overlooked by both producing operations and prospective projects, thus leading to a wide range of studies on ore sorting. The answer to this is the creation of a new term and concept - Profit Recovery™."

Jan 1, 2018

By B. K. Saikia

A preliminary attempt has been made to study the particle size distribution (PSD) of minerals in one of the industrially important pulverized Indian coal sample using computer-controlled scanning electron microscopy (CCSEM). The results show that clay minerals, quartz, pyrite, and pyrrhotite form the bulk of the mineral matter. Minor minerals, such as calcite, dolomite, ankerite, barite, oxidized pyrrhotite, and gypsum are also observed in the coal sample. The PSD of the included minerals is generally observed to be finer than that of the excluded ones in the coal. Thus, the coal rich in included minerals has more small mineral particles, which may affect its reactivity. The proportion of included to excluded is found to be higher in major cases. Si is found to be mostly occurred as quartz and clay minerals, while Al mostly occurs as silicate minerals. Fe is primarily present as iron sulfides, iron oxide, and Fe-Al-silicate. S is partitioned into iron sulfides and gypsum. Most Ca occurs as carbonates and gypsum, with a minor fraction associated with clay minerals. Mg is found to be mainly present as dolomite and clay minerals, with a very minor fraction present as ankerite. The majority of alkali elements are associated with aluminosilicates. P is mostly associated with kaolinite and/or present as more complex compounds containing Al, Si, and other elements as apatite are found to be absent in the coal studied. Ti is mainly present as rutile and kaolinite. The geo-chemical association of the trace elements has also been discussed. Keywords: minerals, Assam coals, Indian coals, CCSEM study

Sep 1, 2012

By W. Y. Liu

A sulfate reducing bacteria strain (named SRB-A) is isolated from sanitary wastewater by using anaerobic technology of Hungate. The studies of physiological, biochemical and phylogenic of the isolated strain are carried out. The colonies of the strain are circle. Cells that are slightly curve, rod-shaped with the size of 1.0~3.0µm in length and 0.8~1.0µm in width. The optimum temperature for growth of the organism is 30~35°C. The optimum pH for growth is 7.0~7.2. Strain SRB-A can use sodium lactate, sodium citrate, sodium acetate, ethanol and acetone as electronic acceptor but can not use glycerol, glucose, sucrose and sodium oxatate. The isolated strain reduces sulfate, sulfide, sulfur, DSMO and FeCl3, then nitrate and nitrite can not be used. The strain has higher tolerance of NaCl, and the optimum growth occurs in the presence of 5%~8% (w/v) NaCl. The result of 16S rDNA sequence analysis indicates that the isolated strain SRB-A is the most similar to Desulfo-vibrio halophilus, and the level of the similarity was 98.4%. The isolated strain has a stronger ability to reduce sulfate, and the level of sulfate reduction reaches about 90% at pH 7 in the liquid medium. 0.6 to 0.8 is the optimum COD/SO42- in the medium for the isolated strain to show better ability to reduce sulfate. At pH 2.5 the level of removal of Cu2+ reaches 96.3%. Under the condition of pH 3.5, the level of removal of Zn2+ reaches 92.6%. When the value of pH reaches about 7, the Fe3+ is precipitated by the formation of Fe(OH)3, and Fe3+ is removed up to 89.4% at last.

Jan 1, 2014