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By S. Chuanyao

In last decade, along with its booming Chinese economy, China?s higher education has experienced rapid growth. In 2010, the number of various colleges totals more than 3500, with 2.2 million faculties registered. Currently there are almost 30 million students studying in the colleges, 3 times more than 10 years ago. Mineral Processing was initiated in 1949 as a sub-discipline of Mining Engineering, one of the 13 first level disciplines. Mineral Processing is now established in 34 Chinese colleges, recruiting 2600 undergraduate students, 540 postgraduate students and 100 PhD students every year. A further 9 institutes offer postgraduate education in this field. More than 3000 graduates majoring in Mineral Processing join the industry or institutions each year. The four-year undergraduate teaching and practical training in the colleges is designed to produce qualified mineral processing professionals. This includes courses in mathematics and natural science, fundamental engineering and basic and specialization courses. Recently, the ?Excellent Engineer Program? was launched to strengthen students? practical capabilities. This is a 3+1 teaching and training model; 3 years of theoretical course study plus 1 accumulated year of various practical studies, either inside or outside the college. As for graduate employment, mining-related major graduates have been in a good demand thanks to the intensive investment in mineral sector by Chinese companies. The shortage of experienced metallurgists generates a greater than 90% employment rate for Mineral Processing graduates. However, the biggest problem we are still facing is the gap between the quality of the graduates and the requirements of industry, as a result of occupation attraction, teaching systems, faculty quality, and so forth. Another problem is international orientation. Although nowadays Chinese-foreign cooperation in college education is popular, collaborative mineral related projects are far less common, leaving much room for improvement. Looking ahead to the next 10 years, we still have the right reasons to estimate continued prosperity in the minerals sector as well as mineral processing education in China. A brief analysis and views on this will also be shared in the presentation. Keywords: China, mining engineering curriculum, excellent engineer program

Sep 1, 2012

By O. Jerez, A. Novoselov, L. Gutiérrez, J. Morales, U. Kelm

"In Chile, the evaluation to reprocess tailings for elements other than the traditional Cu, Mo, Au, and Ag, as well as projects to implement long-term monitoring of mining residue sites are key elements of the government’s roadmap laid out for the mining industry for the next two decades. Characterization routines for tailings and mining residues in general have to be adapted from traditional ore and gangue mineral and micro-chemical studies. This contribution summarizes key aspects for the regional mining industry for a basic characterization of tailings with emphasis on small- to medium-size operations with limited in-house facilities and funds to carry out extensive characterization programs. The oldest tailings in Chile were deposited almost a century ago; this fact gives importance to the recovery of past ore /gangue feed information, process circuits and changes (e.g. acid to alkaline flotation), process water provenance and recovery, meteorological registers, and routines of filling a tailings impoundment. Basic characterization should include X-ray fluorescence spectrometry combined with laser diffraction (LD) granulometry followed by X-ray diffraction (XRD), optical microscopy (OM) and automated mineral analysis (AMA) on a reduced set of samples identified by hierarchical cluster analysis. For this detailed stage, only coarse tailings are recommended for direct a study by microscopy and automated mineralogy (P80 >100 µm); for fine tailings (P80 ~30 µm) a combination of XRD and deposit type adapted sequential extraction are more informative options. In particular, for XRD of clay phases, losses of crystallinity may result in deviation of spectra from standard reference phases due to prolonged storage. To monitor surface alteration, scanning electron microscopy can be complemented by Raman spectroscopy to detect residual reagents on mineral surfaces. For reactivity modeling BET measurements are essential."

Jan 1, 2018

By S. N. Sahu

Attempt was taken in this study to explore the misplacement phenomena in binary mixture in solid-liquid fluidisation system. The binary mixtures of hematite and quartz particles at different sizes were taken. The closed size range particles were taken to minimize the size and shape effect in fluidization. As both the minerals have appreciable density difference, the separation of both minerals with closed size range has an advantage. The experiments were conducted in different permutation and combination of different sizes of binary mixture to observe the fluidization phenomena. The samples were taken at different heights in fluidized zones and analyzed the distribution of particles of both minerals. The fluidization characteristics were evaluated with respect to operating and design parameters. It has been observed that when the terminal velocity of quartz and hematite particles is same or near to each other, then misplacement is significant. In general, the segregation index value is near to one, complete segregation takes place whereas this value is near to zero, complete mixing takes place. The experimental data were used to find out the segregation index for different size ratios of quartz and hematite particles and the values are within 0-1. When the size ratio is 1 or less, complete segregation takes place whereas this ratio is within 1.0-1.4, partial mixing takes place. Similarly, when the size ratio is within 1.4-2.0, complete mixing takes place whereas this ratio is within 2.0-4.6, then it moves towards complete segregation in inversion manner. Keywords: particulate fluidization, misplacement zone, bed expansion, terminal velocity, mixing characteristics, segregation index

Sep 1, 2012

By Y. C. Liu

Arsenic bearing copper-gold ores deposit have been found in most areas of China, especially in southwest. Due to the very closed association between arsenic, copper and gold, conventional flotation and cyanide leaching process may not give positive results. An arsenic bearing copper-gold ore in Sichuan province ,with gold grade of 10.12 g/t, 0.6% Cu and 0.14% As, is characterized by superfine grains with -40 microns fraction accounting for 70.9% and the gold enwrapped mainly by pyrite and tennanite accounts for 34.31%. Arsenic in this ore occurs in isomorphism, deposited in tetrahedrite. The ore was processed primarily in two stage flotation to get copper bearing gold concentrate and pyrite bearing gold concentrate respectively, and sequentially processed by leaching. Under the pressure of 300 KPa and 110~115 ?, the copper-gold concentrate was leached by an oxidizing and catalyzing leach agent then copper and gold were separated from each other in leach solution. The pyrite bearing gold concentrate was processed by cyanide leaching with the leach residue as sulfur product. The test results showed that copper recovery was up to 88.89%, gold recovery up to 89.18% and sulfur recovery up to 92.64%.

Jan 1, 2014

By Tamal K. Ghosh

In this study, the QEMSCAN technology is used to acquire quantitative modal, textural, mineral association and liberation data on different products generated from with or without washing, fractionation by size and density using screens and heavy liquids/panning, which has provided significant information on the quality and beneficiability of four categories of low Grade iron ores from Jharkhand-Orissa region. The deposit of low Grade iron ore has been categorized into four categories viz. Grade-I with <45% Fe(t) a) containing shale rich type and b) BHJ rich type; Grade-II with 45-55% Fe(t) and Grade-III with >55% Fe(t) containing conventional flaky, hard, kanga, lateritic, shale and BHJ litho/ore types in varied proportions. Mineralogy is similar across all samples being hematite, martite, goethite, kaolinite and gibbsite. Banded Hematite Jasper has difficult liberation characteristics due to highly compact banded mode of silica mineral occurrence with hematite. In all categories, the grade dilution is by the presence of 1) ?Discrete gangue rich litho types? at lump size and 2) ?Within ore types?. The second type of grade dilution contains coating of gangue phases around the iron ore minerals and different degree of locking of gangue phases within iron ore minerals. Further characterization and beneficiation assessment details are discussed in this paper.

Sep 1, 2012

By Shugang Hu

According to XRD, DTA and SEM detections, the hydration products of blast furnace slag (BFS) based cementing material SL, SLG. were studied in different age periods. The XRD analysis of cementing material SL hydration products showed that the composition of hydration products were mainly amorphous substances, few crystalline substances. Characteristic peak of ettringite hadn?t been found in the spectral line of DTA, and it hadn?t been found in the figures of SEM, either, which was accordant with the conclusion that the cementing performance of SL mainly coming from gel of hydrated calcium silicate (CSH) and hydrated calcium aluminate. However, the main hydration products of SLG are Aft, CSH, and AFm, which are similar to Portland cement. All results suggest that BFS is a suitable base material for cementation. Keywords: blast furnace slag, backfilling cementing material, hydration products, cementing performance

Sep 1, 2012

By Jyotirmoy Sarma

The surface-active agent, like sodium humate, in the present systems produces a very stable suspension. Saline water up to 15% is used as a flocculating agent for recovery of water from the dispersed phase containing 1% solid. The recovered water in the presence of humate at different concentrations (0.05-0.2%) and at pH 8 also produces a stable dispersed phase of iron ore fines and tailings. The beneficiation techniques adopted in the present systems can increase ~ 2-3% iron value in the concentrate of iron ore fine, however, for tailings the increase in iron value is not observed. Keywords: beneficiation, flocculation, iron ore fines, tailings, saline water, surface-active agent

Sep 1, 2012

By Y. L. Tian

Low-grade bauxite with A/S of 4.4 from Henan province was used as raw material and the selec-tive grinding of bauxite, grinding efficiency, particle size and Al2O3 and SiO2distributions of ground products were investigated using ball and vibration mills. The results show that the selective grinding can be used to realize the separation of aluminum from silicon within a certain particle size. The optimal grinding conditions of the ball mill with bauxite are as follows: grinding material to charge ratio, 1.2, charge volume ratio, 40%, pulp con-centration, 70wt%, medium size distribution, F30mm:F20mm:F15mm=20%:50%:30%. Under the conditions, the weight rate of ground product with A/S over 7.5 is 27% and the recovery of Al 2O3is 30%. The optimal grinding condition of the vibration mill with bauxite are as follows: grinding material to charge ratio, 0.9; charge volume ratio, 70%; concentration, 70%; medium size distribution, F40mm:F30mm:F20mm=20%:30%:50%. Under the conditions, the weight ratio of ground product with A/S over 7.5 is 25% and the recovery of Al 2O3is 27%. The research is significant for the rational and economical utilization of the low-grade bauxite.

Jan 1, 2014

By J. Jirestig

Poor grade iron ore, suffering from interlocked particles, is challenging for any process technology. Extensive grinding is required to attain liberation and to yield concentrates of desired grade. Fine particles are commonly very difficult to retrieve, resulting in value losses to tailings. In this paper, results from HGMS tests on fine to ultra fine hematite are reported. Special emphasis is put on slurry flow velocity. If hydrodynamic drag force, i.e. flow velocity is not controlled and kept constant during the feed and/or rinse phase, fine particles will not be captured and retained. Flow velocity control and constant flow during separation are achieved by discharge valves/slots and parallel magnetic flux and pulp flow configuration. In tests, increased slurry velocity from 178 to 268mm/s caused Fe-recovery to drop from 78 to 48%. Proving that flow velocity control is essential to optimise grade and recovery. HGMS tests at the Metso mineral laboratory on natural (weathered) hematite fines clearly show a large potential to recover valuables, currently lost to tailings. Even at particle size distributions as low as D80=35µm concentrate grades and recovery are very satisfying. Two samples, in-plant desliming rejects (D80=35µm and 50µm) where significantly upgraded and recovered, from 45,3% to 63,6% and 53,0% to 63,4% Fe, at 73,8% and 81,1% Fe-recovery respectively. Other types of in plant rejects, such as gravity separation or WHIMS tailings, also benefits from HGMS separation. Gravity separation reject, 55,8% Fe, at D80=500µm was tested, yielding a magnetic concentrate of 60,8% Fe at 50,7% Fe-recovery. The results indicated that the hematite was poorly liberated. HGMS separation was repeated after a regrind to D80 150µm, resulting in a magnetic concentrate of 62,8% Fe at 75,9% Fe-recovery. The tests prove that hematite, presently lost to tailings streams, can be recovered by HGMS and thereby significantly contribute to improved overall economy. Keywords: HGMS, magnetic separation, recovery of ultra-fine hematite, Indian hematite ores, hematite recovery from tailings

Sep 1, 2012

By B. W. Zhao

Quantitative analysis of minerals composing in ore is primary in process mineralogy, a veracious quantification and analysis is very crucial to optimize or design a beneficiation process, especially for a low grade and complicated ore. This paper will discuss a SEM-EDS based quantitative analysis developed in JKtech Australia through an example from Jinchuan lean ore. For a low grade, com-plex intergrowths and texture lean ore, chemical phase analysis of value minerals and identification by optical microscope are very essential, unite the SEM-EDS based quantitative analysis, we can understand exactly the lean ore, explain and quantify the process performance.

Jan 1, 2014

By Markus A. Reuter, Bernardete Castro, Antoinette van Schaik, Han Remmerswaal

This paper describes the inseparable relation between product design, liberation, and metallurgical recovery in the optimisation of the recycling of passenger vehicles. This is illustrated by the use of an optimisation model that uses among others a material combination matrix based on metallurgical process data, which depicts the consequences of the quality of intermediate recycling products on the metallurgical material recovery and final alloy metal quality. Various simulations will illustrate the effect of changes in product design and hence liberation on the recycling of end-of-life vehicles. Although this paper focuses on cars, the discussion is equally valid for any end-of-life product. Calibration of the model will be discussed with reference to experiments carried out in order to study the optimal recovery of aluminium applications used in passenger vehicles.

Jan 1, 2003

By Rob Morrison, Andrew Scott

"Long before a modern mine commences operations it has already become a wealth of information. After start up, it can generate enormous quantities of data - especially with semi-automated data acquisition by instrumented mine equipment.However, much of this data is of limited use for evaluation of (potential) performance unless it links in some way to the site business model.An underlying reason for this waste of data is that the different cultures, financial, technical, community, environmental, etc, not only have many areas of interest but also have very different conceptual models by which they evaluate performance.It is too ambitious to attempt to bring all of these cultures together - in a single step.However, the success of the Mine to Mill - project has demonstrated that substantial operational value can be added by using a more integrated approach to comminution. The next logical step is to integrate measurement and then to track performance from ore body model to saleable product and waste disposal. From resource to product also represents a path from very sparse, highly variable data to much more detailed measurement and more representative sampling.However, in both cases the data collected is strongly focused on the technical requirements - not on the business model.This paper considers how to define at least some of the key decision points in terms of some case studies.Performance data from many areas might be used to derive simple models which can then be used for forecasting and optimisation of planning."

Jan 1, 2003

By D. W. Lui

Tangdan copper oxide deposit, the largest independent copper oxide deposit in China so far, is located in the northeast of Yunnan province, southwest of China. The ore from this deposit is characterized by: low grade, high oxidation ratio, and fine-grained disseminated, resulting in poor flotation recovery. The analysis of plant flotation data reveals that the loss of copper minerals into tailings is mainly with coarse size fraction due to insufficient liberation and fine size fractions, especially minus 10 microns fraction, which proved to be very difficult-to-float with conventional flotation. In order to improve the performances of plant flotation of this ore, laboratory flotation tests were conducted with the pure malachite, which was the principle copper oxide mineral in Tangdan copper ore deposit. The results obtained suggested that a finer grinding (up to -325 mesh or even -400 mesh) be needed to decrease the loss with coarse size fraction, and vacuum flotation is a promising way for the recovery of the fine malachite effectively.

Jan 1, 2014

By E. Alldén Öberg

In 2004, LKAB decided to start a basic engineering study in expanding its existing production lines at the Malmberget mine site. It was expected that some of the production lines would become bottlenecks with reference to capacity. In this study, the sorting plant is examined and the results show that several unit operations will be limiting under current operating conditions. An additional purpose with the study was to investigate how replacement of some machines would influence performance and if production plans for the coming years might be achieved. Steady-state simulations using the software Modsim? were extensively used to study process performance for different operating conditions, such as iron content and size distribution in run-of-mine ore. Model parameters were derived from pilot plant data and when possible from ex-isting circuits. A complication for the simulations was the lack of relevant data and therefore some of the initial results were only indicative. The result shows that installation of new screens would give a much better operation, but also new crushers would be an improvement. This, since they can be run with full crusher chamber and tighter CSS. During 2007, most of the proposed remedies were implemented and the result is that the bottle-necks are gone, and the grades and material balances are even better than what was envisioned from the simulations.

Jan 1, 2014

By A. Üçyildiz

Magnesium borates of varying compositions and properties are synthesized using different reagents and methods for the possible potential uses as termoluminescent material, anti-wear and anti-friction additive, fire retardant, catalyst for the conversion of hydrocarbons, whisker material and ferroelastic material. In the current work, the conditions for synthesizing MgB4O7 compound by high-temperature solid-state reactions were investigated using boric acid and magnesium oxide as the starting materials. The MgO:B2O3 mole ratios applied in the experiments were 1:1, 1:2, 1:3 and the thermal behaviours of each mixture were studied between 25~1200°C by TG/DTA analyses under static air atmosphere to find out the probable formation temperature of MgB4O7 phase. Considering TG/DTA results, freshly prepared boric acid and magnesium oxide solid mixtures were heated at predeter-mined temperatures and the phases were identified by XRD analyses. Accordingly, MgO:B2O3 mole ratio of 1:2, heating temperature of 950°C and a reaction time of 2 hours were selected as the optimum conditions for the formation of maximum amounts of MgB4O7. After obtaining solids prepared at the pre-determined optimum conditions, their chemical composition, IR spectrum, TG/DTA pattern, B.E.T. surface area value, particle size distribution and SEM images were deter-mined to point out the possible use areas. Experimental results showed that it was not possible to obtain pure product at the optimum conditions due to formation of minor amounts of t-Mg2B2O5 and the presence of some unreacted B2O3. The product synthesized has the potential for use as a corrosion inhibitor on some metal surfaces.

Jan 1, 2014

By A. A. Lavrinenko, N. I. Gluhova, L. M. Sarkisova, D. V. Makarov

"The purpose of the study is to study the feasibility of using sodium diisobutyl dithiophosphinate (DDP) to enhance the recovery of platinum group elements from low-grade refractory copper-nickel ores characterized by a portion of nickel and platinum group elements (PGEs) locked in the dominant sulfide mineral — pyrrhotite. These ore characteristics dictate the need to produce a bulk PGE-containing sulfide concentrate due to the difficulties of producing selective concentrates without a significant loss of the metals.New data on the adsorption and flotation performance of DDP-containing collectors were obtained by measuring the electrode potential, hydrophobicity of the sulfide mineral surfaces and by means of extraction spectrophotometry and flotation studies. The interaction between DDP, pyrrhotite, and pentlandite leads to the formation of surface hydrophobic layers consisting mainly of disulfide and a small amount of metal compounds. These adsorption layers are formed by the reaction with butyl xanthate. In the case of cooperite, DDP reacts with the surface, forming not only disulfide, as in the case of butyl xanthate, but also a complex platinum compound. DDP-containing agents demonstrate stronger collecting properties with respect to sulfide minerals of copper-nickel ores compared to butyl xanthate, which is explained by a stronger hydrophobizing effect and foaming properties.The addition of a combination of DDP-containing agents and butyl xanthate at a ratio of 3:1 for the recovery of sulfides and PGEs in the bulk flotation of copper-nickel ore made it possible to improve the recovery of Ni, Pt, and Pd by 13.6, 9.2, and 9.4%, respectively, relative to the recovery achieved in flotation with butyl xanthate.Bulk flotation with the addition of a composition of DDP-containing agents and butyl xanthate allows the most complete recovery of all valuable elements and is the only technologically feasible method for processing of lowgrade ores, when it is impossible to produce without loss high-grade selective concentrates suitable for smelting."

Jan 1, 2018

By V. I. Ryaboy, V. P. Kretov, S. E. Levkovets, I. V. Ryaboy

"Using the flotation of a gold-containing ore from a deposit in Kazakhstan as an example, we have conducted a study designing dialkyldithiophosphate collectors, in addition to xanthates, for the flotation of hard-toenrich gold-containing ores to increase gold recovery.The increased flotational ability of the dialkyldithiophosphates was determined by their surface activity at the liquid-gas interface and their hydrophobic ability, the changing of which allowed us to control the collecting power and selective ability of the dialkyldithiophosphates. The studying of the surface activity of aqueous solutions was done using the stalagmometric method and the evaluation of the hydrophobic ability was done in percentage of the relative value of the zinc ion binding in the solution in standard conditions.Studying the influence of surface activity in our designed dialkyldithiophosphate collectors, with their close hydrophobic ability, showed that even with a small increase in surface activity in their aqueous solutions, gold recovery increased by 2-3% in laboratory conditions. Using this enabled us first to apply the dialkyldithiophosphate collector BTF-161 at a plant in Kazakhstan, and then to introduce the specially designed dialkyldithiophosphate collector BTF-163, which has been in use since. Further study of dialkyldithiophosphate activity based on this concept showed us that for the range of short-chain dialkyldithiophosphate collectors with a chain length of up to ?5, the effectiveness of ore processing became lower the higher their surface activity got, with relatively small differences in their hydrophobic ability. For long-chain dialkyldithiophosphates with a chain length of over ?5, ore processing effectiveness increased with the increase of their hydrophobic ability.Based on these studies, a new effective dialkyldithiophosphate collector, BTF-1517, was designed. Using this reagent in continuous gold recovery tests allowed us to reach an 84.21% recovery with a concentrate quality of 15.66 g/t, while using the applied collector BTF-163 in similar conditions led to the recovery of 82.87% with a concentrate quality of 15.65%. As a result, the Kazakhstan processing plant decided to conduct industrial tests with the BTF-1517 collector."

Jan 1, 2018

By M. Prasad

Growing concern over increased levels of atmospheric carbon dioxide has prompted new interests in development of materials and techniques for its sequestration. Various research and developmental work on different aspects of carbon capture technology are being extensively carried out worldwide. The main objective of the present work is to synthesize a HAS material having high capacity and robust ability for recycling to capture greenhouse gases with special reference to carbon dioxide (CO2) from the sources from where it is released to the atmosphere. Existing CO2 capture techniques involves the use of solid materials that lack sufficient stability for repeated use or liquid adsorbents that are expensive and require significant amounts of energy. Keywords: greenhouse gases, carbon capture, solid adsorbent, HAS material

Sep 1, 2012

By Y. H. Tang

For its surface features, micro-sized hematite is usually difficult to recover by magnetic separation; especially, the existing high gradient magnetic separator in industry can not utilize collecting matrix with thin silky rods for its property of being easily blocked; the lower size limit for recovery of micro-sized weak magnetic minerals is about 0.019mm, some even is 0.037mm. This paper introduces the application of the combined new technique of water-air joint discharging of concentrate and collecting matrix with different diameter silky rods in the field of recovery of micro-sized hematite by high gradient magnetic separator. The commercial test result for recovery of a certain hematite with size about ?0.037mm shows that the recovery can be promoted by 16.81% with basically same concentrate grade.

Jan 1, 2014

By Cheng Wei

Fly-ash was used as adsorbent to remove butyl xanthate from aqueous solution in this study. Adsorption kinetics investigation reveals that the adsorption process abides by the Lagergren-second-order Kinetic Model, and fine fly-ash prepared by grinding has a higher second-order adsorption rate as 1.25 g/mg?min and a higher saturated adsorption amount as 10.92mg/g. Four influencing factors as adsorption temperature, solution pH, consumption of fly-ash and adsorption time were investigated. Testing results indicate that butyl xanthate removal rates declines slightly with the temperature increase within the range of 15-50?, increases slightly when pH rises from 7.27 to 8.01 and then declines from 99.65% to 98.25% when pH rises from 8.01 to 11.10. An enhancement of removal rates can be observed by increasing the consumption of the adsorbing agent or prolonging the adsorption time. Thermal desorption was adopted to regenerate the used fly-ash, and test results show that fly-ash possess good regeneration performance and could be used as adsorbent repeatedly with little influence on the adsorption capacity.

Sep 1, 2012