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By A. Y. Senchenko, Y. V. Kulikov

"The most common technique for selection of grinding equipment is the Bond method implying determination of a ball mill work index (BWi). The method is perfect for greenfield projects where a ball mill must be sized to grind an ore to 80% passing 75-100 µm. Finer grinding will require application of specific correction factors to a standard equation since initially the method was not designated for sizing of fine (minus 75 µm) grinding mills. Significant issues are related to selection of grinding equipment for treatment of originally fine materials when the standard procedure is not applicable. In 1984, Levin published his special technique titled as “A proposed test for the determination of the grindability of fine materials”, where he offered to use the standard Bond ball mill for determination of a specific grinding energy. However, this method did not meet with wide recognition. In 2017, Institute TOMS under guidance of JKMRC’s specialists performed a testwork aimed at verification of a new universal technique for determination of grindability of initially fine materials. An object was to test three aged tailings samples for the subsequent modelling of comminution circuit and evaluation of potential throughput of the existing ball mills with final grind size of ?80 passing 53 µm. In parallel with development of the universal approach, TOMS’ specialists carried out tests according to the Levin method in order to compare the data resulted from two methods. The results from lab ball mill testing on three products following the alternative test methods are presented in this paper along with the testing methodology and results analysis. Specific energy was calculated for regrinding of the materials to the required size. Difference of the examined methods and assessment of their applicability for sizing of full-scale equipment are explored."

Jan 1, 2018

By M. Abdollahy

Solvent extraction of gallium from Bayer solution of Jajarm Alumina plant was investigated us-ing Kelex100 as extractant. Taguchi experimental design method was used in order to optimize the separation factor of Ga and Al. Optimum conditions were obtained as follows: Temperatuer: 65°C, volume ratio of aqueous phase to organic phase: 3.0:1.0, process time: 60min and organic phase containing 15vol.% Kelex100, 5vol.% isodecanol in kerosene. In this conditions, 74% gallium and 0.3% aluminum was extracted and separation factor was obtained 828.63.

Jan 1, 2014

By A. N. Zagorodnyaya, T. N. Bukurov, Z. S. Abisheva, A. S. Sharipova

"The paper describes the results of stripping of copper production dusts by leaching with aqueous soda, nitric acid solutions and recovery from solutions resulting in the production of lead sulphate, tribasic lead sulfate (TBLS), ammonium perrhenate, zinc, copper-cadmium cake.The combination of two stripping operations under chosen optimal conditions allows the recovery of 98% rhenium, 82% lead, 92 % copper, and 96% zinc and cadmium each. The major amount of rhenium (~ 80%) is recovered at the carbonization stage, and other metals - at the nitric acid leaching stage.Lead sulfate was precipitated by mixing solutions resulting from carbonization and leaching. Tribasic lead sulfate was produced by dissolving lead sulfate in sodium hydroxide solutions. Rhenium was recovered from mother liquor resulting from lead sulfate precipitation by liquid-liquid extraction and zinc was recovered from raffinates. Trialkylamine (TAA) was used as an extractant for rhenium recovery and di-2- ethylhexylphosphoric acid was used for zinc recovery. Optimal liquid-liquid extraction parameters have been defined allowing the recovery of 96% rhenium in crude ammonium perrhenate and 94% zinc in sulfuric acid solution. Based on the experimental data, the flowchart for dust processing to produce salable products - lead, rhenium, zinc salts has been suggested."

Jan 1, 2003

By Venkataramana Runkana, Aditya Pareek, Vishnu Masampally, Nagaravi Kumar Varma Nadimpalli

"Recovery and grade of the ore produced are two important metrics, which define the profitability of a mineral processing plant. Achieving high grade and high recovery at the same time in a mineral processing plant is difficult due to conflicting nature of the two objectives. To explore the operability limits of the plant operations and find the set of operating conditions that can help achieve the best possible recovery and grade, there is a need to solve a multi-objective optimization (MOO) problem. Past research focused on building a plant-wide simulation model or on optimization of individual units or a part of a mineral processing plant like grinding circuit, crushing circuit, etc. However, it is necessary to consider optimization of the complete plant in order to optimize the plant performance. Here, we have formulated the mineral processing plant performance optimization as a MOO problem. We have applied machine-learning algorithms such as random forest to build models to predict the recovery and grade of the ore. A non-dominated sorting-based multi-objective evolutionary algorithm called NSGA-II (Non-dominated Sorting Genetic Algorithm II) was employed to solve the MOO problem. Since the number of parameters that influence recovery and grade are quite large, we have applied machine-learning algorithms for feature selection or identification of key process variables. Pareto optimal conditions were determined for manipulated variables like grinding mill throughput, speed ratio at SAG mill, speed of centrifugal pump, water addition at different locations etc. The results obtained are useful in identifying the operability of a mineral processing plant to achieve the optimum grade and recovery for a given feed grade and the processing circuit. INTRODUCTION Copper is majorly mined or extracted as copper sulfides from large open pit mines in porphyry copper deposits. Among all the available ores, sulfides are the most commercial ores, especially chalcopyrite (Greenwood and Alan, 1997). Copper grade in these ores generally lies between 0.4 to 1.0%. In order to perform smelting operation, the grade of copper has to be improved to around 30% (Biswas et al. 2013). This targeted copper grade is achieved through two stages of mineral processing. Firstly, the copper in the ore has to be liberated by crushing the mineral rock. Secondly, the liberated copper in the crushed ore is then physically separated from other minerals like nickel by froth flotation techniques."

Jan 1, 2018

By João Queiroz, Cristian Marquez-Sarmiento, Luiz Teixeira

The removal of various metals from process waters and effluents is usually done by precipitation of the corresponding hydroxide. Manganese however is one metal that does not respond efficiently to that approach. It may be seen in its eH X pH diagram that the way of oxidation to Mn IV rather than hydrolytic precipitation of the Mn II ion as its hydroxide, is the way to efficient precipitation of Mn in the pH range 6 to 10. We studied the use of oxidants O2; NaClO; H2O2; Caro´s Acid (H2SO5) and the combinations of O2 or H2O2 with Na2S2O5, and H2O2 with NaClO, for the oxidative precipitation of Mn from synthetic solutions starting with 10 mg/L Mn, at 25 oC. In adequate conditions, which include pH > 8, it is possible to reach final [Mn] less than 0.1 mg/L in 60 minutes of reaction time.

Jan 1, 2014

By G. Voiloshnikov, A. Bogudlova

"The deleterious effect of carbonaceous matter during cyanidation of gold ores (so called preg-robbing) has been recognized for many years. Based on this, a new method using flotation to reduce the content of carbonaceous matter was developed. Low-sulfide gold-bearing ore with carbonaceous matter of 0.14% from a Russian deposit was processed. The purpose of these tests was to compare two flow sheet options. Option I comprised removal of carbonaceous product prior to sulfide flotation. Option II comprised removal of carbonaceous matter from flotation concentrate. It was found that the content of carbonaceous material can be reduced in sulfide gold-bearing concentrate prior to leaching. High gold recovery was observed during the separation of carbonaceous material prior to sulfide flotation using Option I. Due to lower reagent consumption the costs for reagents were decreased using Option II. The results have shown the effectiveness of a new method. Patent No. 2783808 was obtained for removal of carbonaceous material prior to sulfide flotation. This information will be used to design a large processing plant flow sheet in Russia."

Jan 1, 2014

By S. L. Gao

Based on the differences in hardness and density of diaspore and aluminosilicate minerals which usually exist in Chinese diasporic bauxite, It is analysed that bauxite of this kind is difficult to be separated effectively by classification and normal gravity separation, and cyclonic centrifugal field was thus proposed to be carried out, in which classification can take place according to the size difference resulted from selective grinding, what?s more, the separation function according to density difference is expected to take effect at the same time, and then cyclonic separation tests for diasporic bauxite of A/S 4.39 and grinding 61.90% -0.074mm were carried out tentatively. The results showed that the accretion of feed pressure can offer strong enough centrifugal force for cyclonic separation with result that separation function according to density difference is effectively intensified, by the increasing of this parameter, underflow and overflow of A/S 7.64 and 2.18 can be processed at the same time, and the recovery of Al2O3 in underflow is 71.78%; judging by the flow ratio, the spatial locality envelope of zero vertical velocity do constringe to the vertical axis by the enlarging of diameter ratio of apex to vortex, overflow and underflow of A/S 2.08 and 6.5~7.0 can be processed by controlling this structural parameter, which is possible to offer a technological method for low-grade bauxite to de-sliming beforehand.

Jan 1, 2014

By Y. S. Sun, P. Gao, Y. F. Li, J. W. Yu

"Oolitic hematite ore is one of the most refractory iron ores in the world. It is not feasible to separate iron minerals from raw ore by conventional mineral processing methods. In recent years, a new technology called coal-based reduction followed by magnetic separation has been employed to produce metallic iron powder from oolitic hematite ore effectively. In order to find the nucleation mechanism, a thermodynamic analysis of the carbothermic reduction of oolitic hematite ore was conducted by the HSC 6.0 thermochemical software. The phase transition and microstructure changes during the coal-based reduction were also investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results showed that the iron oxides in the oolitic ore were reduced to metallic iron following the route of Fe2O3–Fe3O4–FeO–Fe in reduction process. The reduction reactions preferentially occur in the high activity regions to form a higher concentration of Fe elements, and then more supersaturated Fe separated out to form new phase nuclei. Under the action of homo-aggregation and principle of minimum free energy, the iron cores continuously absorbed migratory Fe around and grew into quasi-spherical iron particles embedded in slag phase. INTRODUCTION With the rapid increase of steel industry, premium grade iron ore in China has been gradually exhausted, and its supply has become bottleneck for the development of iron and steel industry (Guo et al., 2015). Therefore, it is urgent to exploit the refractory iron ores, such as oolitic hematite ore. Oolitic hematite ore is widely distributes in France, Germany, America, Canada, Pakistan, China, and among other countries (Maynard and Van Houten, 2004; Li et al., 2011). In China, the explored reserve of oolitic hematite ore is 3.72 billion tons, which accounts for approximately 1/9 of total iron ore resources of China (Gao et al, 2016). Oolitic hematite ore possesses complex composition,"

Jan 1, 2018

To extract the gold from refractory gold concentrate with high sulfur and arsenic, the gold concentrate was catalytically oxidized to expose the gold for cyanide leaching. The effects of reaction temperature, initial nitric acid concentration, reaction time and initial gold concentrate concentration on the conversion rate were studied. The results show that the appropriate conditions for the catalytical oxidation of this gold concentrate are: reaction temperature of 65 oC; initial nitric acid concentration of 25% (wt.); reaction time of 1.5 hours; initial gold concentrate concentration of 10% (wt.). Under such conditions, the conversion rate of gold concentrate is 92%. The solution can be used to prepare nano-iron oxide red pigment. Gases released in the process can be recycled and reused by oxidation absorption. A chemical background of catalytic oxidation is proposed.

Jan 1, 2014

By F. Z. Dong

The paper is mainly about a study on the techniques of separating iron from pyrite cinder of a certain sulfuric acid plant in Shandong province. The main components of the cinder are Fe2O3 and SiO2, and the degree of liberation of iron mineral and gangue is very high. So the iron concentrate with higher degree of iron and lower grade of silicon and sulfur can be achieved by reverse flotation. The iron grade of the concentrate reaches 63% and the recovery of iron is no less than 63%. And the most important influencing factor of the flotation is the temperature of the pulp. A better guideline can be achieved by magnetic separation. The cinder is magnetizing roasted for 15 minutes with temperature of 800?, and the concentrate with the iron grade 64%, sulfur grade 0.2% and iron recovery 85% can be obtained by two stage magnetic separation. A rotary kiln has been built to deal with the pyrite cinder, and the result of the industrial magnetizing experiment and magnetic separation is satisfying.

Jan 1, 2014

By N. Acarkan

Beneficiation of the pyrite concentrate of the Kastomonu-Küre (Northern Turkey) copper ore seems to be attractive due to its high Cu, Co, and Zn contents. Pyrite concentrate were used in the experimental studies. Cu, Co, and Zn were recovered from the concentrate by the sulphatizing roasting, leaching and the precipitation using H2S. Sulphatizing roasting experiments were carried out in a rotary furnace and the optimal roasting conditions were found to be at 650°C roasting temperature and 3.0 h roasting period and addition of Na2SO4 of 3 % for the concentrate containing 0.58% Cu, 0.22% Co, and 0.04% Zn. Then, the roasted product was repeatedly leached with 10 g/L H2SO4 solution. Optimal conditions were found to be 60 oC leaching temperature, 2 h leaching period, and 30% pulp density. Leaching efficiencies for Cu and Co were over 99 %. The valuable metals in the pregnant solution were selectively precipitated by H2S as sulfides. Selective precipitation of Cu, Zn, Co was achieved by adjusting the pH and the temperature of the leach solution. Final metal recoveries of 99.20% Cu, 99.40% Co, and 95.60% Zn were attained. The precipitated sulphides are marketable products. Roasting gases with their 15% SO2 content are suitable for the production of H2SO4 and the leach residues can be integrated with the iron ore processing plant as they contain 57.50 % Fe, 17.70% gangue (SiO2, CaO, etc.), 0.04% S, and 0.06% non-ferrous metals.

Jan 1, 2014

By E. R. Bobicki

"Low-grade ultramafic nickel ores, while representing a large potential nickel resource, are difficult to process due to their serpentine content. Microwave treatment is proposed as a technique to improve the beneficiation of ultramafic nickel ores by converting the constituent serpentine to olivine. The present paper reviews the microwave heating response of ultramafic nickel ores and resultant changes in mineralogy, as well as effects on grinding and slurry rheology. Beyond nickel extraction, microwave treatment improves the mineral carbon storage capacity of ultramafic ore tailings, providing a potential source of additional revenue via the sale of carbon credits. The combined positive effects, considered in the context of the whole operation, suggest an economically viable process is possible.INTRODUCTIONAs high-grade deposits become depleted, the processing of low-grade ores has become increasingly important. One such resource is low-grade ultramafic nickel ores. While representing a large source of nickel, these ores are difficult to process due to their serpentine content. Serpentine is a phyllosilicate mineral consisting of 1:1 stacked sheets of silica tetrahedra and magnesium hydroxide octahedra. There are three primary polymorphs: lizardite (platy), antigorite (corrugated) and chrysotile (coiled, fibrous). The anisotropic nature and non-spherical morphology of serpentine particles leads to complex rheology. Suspensions of serpentine minerals, especially those of chrysotile, exhibit high viscosity and yield stress, which can have a negative effect on comminution, flotation and dewatering operations. In flotation, serpentine is known to slime-coat pentlandite, a valuable nickel mineral, and form bubble-fibre aggregates that report to the froth, reducing nickel concentrate grade and recovery. Methods used to counteract the effects of serpentine in processing include desliming, the addition of chemical dispersants, salts or acid, and dilution (Bobicki et al., 2014a). Microwave pre-treatment has been proposed as an alternative way to eliminate the deleterious effects of serpentine in ultramafic nickel ore processing by converting the serpentine to olivine via dehydroxylation, which occurs at 600-700oC (Reaction 1). Olivine is isotropic, consisting of isolated silica tetrahedra linked by octahedrally coordinated magnesium ions, and has the same surface potential as pentlandite at the pH of flotation (~pH 9). Furthermore, since olivine is more reactive to CO2 than serpentine, microwave pre-treatment creates an opportunity to store more CO2 in tailings, an attractive option for mining operations looking to increase their bottom line where carbon pricing exists."

Jan 1, 2018

By G. Bulut, Ü. Yenial

"Heavy metals contamination in aqueous systems can be found in a variety of industries, in particularly mining, metal processing, finishing and plating. Water containing more than 0.5 ppm heavy metal considered as a toxic due to harmful effects on health. The major techniques employed for heavy metal removal from industrial wastewaters include precipitation, reduction, ion-exchange, and adsorption. Adsorption is a heavy metal removal method for aqueous systems. As a common adsorbent, activated carbon has been used in treatment but it is ineffective on some elements. Thus, there has been a research for developing highly effective and selective adsorbents. In this study the adsorption of lead and arsenic ions on to coal waste and red mud waste was studied. The experimental parameters were determined as pH, equilibrium time and the initial concentrations, activation by heat treatment and the blend of adsorbents. According to their adsorption capabilities, red mud was found to adsorb lead and arsenic ion with high efficiency but coal waste did not adsorb arsenic ion. However the binary adsorptions of these ions were enhanced the adsorption efficiencies. In addition the blend of coal waste and red mud affected the adsorption efficiency. INTRODUCTION As a result of rapidly developing industry and excessive use of water resources, the need of clean water and wastewater management appear as a problem. Wastewater recycling activities and researches come to the fore for an effective use of wastewater. Recycling of wastewater, which contains heavy metals harmful to the environment and human, is a difficult process. Heavy metals are generally divided into three categories: toxic metals, precious metals, radionuclides. Wastewaters from various industries, containing heavy metals, are the main polluters of water and soil. Although their toxic structures, heavy metals are used extensively in industry as they have technological significance. Usually mining industry, metal industry and industrial organizations produce heavy metal containing wastewaters (Volesky 1990, Ting and Lawson 1991, Bishop 2002)."

Jan 1, 2018

By Katarina Theander, Robert J. Pugh

The generation of froth with a critical degree of stability and height is an important aspect of the froth flotation. In this paper we have studied the synergism and anti-synergism in frothing behaviour in a mixed flotation collector/frother mixture (a model fatty acid; sodium oleate and a model frother; nonionic (polyethyleneoxide alkyl C14E6). Values of the collector / frother molecular interaction parameters (the ß-parameters) were determined from the surface tension data using regular solution theory. The frothing characteristics of the system were evaluated using a glass column equipped with a series of conductivity electrodes, which enabled the water content of the froth to be determined. From these measurements, the dynamic frothability and static froth stability were determined. It was concluded that the synergism/anti-synergism in frothability was depended on the molecular composition of the surfactant system, the diffusion of monomer to the thin film interface and on the breakdown of the mixed nonionic/anionic micelles.

Jan 1, 2003

By N. D. Ilankoon

"The use of thiosulfate as an alternative lixiviant for cyanide to treat complex refractory ores followed by the use of ion exchange resins (IX resins) for gold recovery has become an industrial reality. In this study, polyethylenimine (PEI) coated iron oxide magnetic nanoparticles (MNPs) were used to recover gold from the leaching solutions that consist of calcium thiosulfate, copper and gold. The gold loaded MNPs were easily separated from the solution using an external magnetic field. Proposing a novel adsorbent with characteristically easy solid-liquid separation, to recover gold from synthetic thiosulfate leaching solutions and gold elution and reuse of MNPs were the main objectives of this study. Adsorption isotherm studies revealed that the data fitted both Langmuir and Freundlich isotherm models equally well. The maximum adsorption capacity was 18.5 mg/g at pH 8 and 50?C. According to thermodynamic studies the physisorption process was exothermic and spontaneous. Gold and copper elution, and the regeneration and reuse of the nanoparticles were investigated and promising results were obtained. Different elution systems comprising sulfites, chlorides, glycine, EDTA (ethylenediaminetetraacetic acid) and sodium hydroxide were considered. Among them, EDTA for copper elution and NaOH for gold elution were the most efficient eluants. Regeneration and reuse studies revealed that the MNPs can be used for several cycles without significant performance loss. INTRODUCTION Although cyanidation has been used for gold leaching for more than 100 years, some major drawbacks associated with cyanidation have led to a quest for alternative lixiviants for gold leaching. Cyanide is ineffective in treating carbonaceous refractory ores as gold cyanide complex is adsorbed onto the native carbon in the ore itself known as preg-robbing. On the other hand environmental concerns associated with cyanidation drives the need for environmental friendly alternatives for cyanide. As of today, thiosulfate is known to be the most extensively studied and most promising alternative lixiviant for cyanide in both technical and environmental perspectives (Aylmore and Muir 2001, Oraby 2009)."

Jan 1, 2018

By C. Hazotte, M. -O. Simonnot, V. Houzelot, B. Laubie, M. Guilpain, B. Jally

"More than 400 plants in the world are able to accumulate nickel (Ni) in their aerial parts at concentrations higher than 10 g per kg of dry biomass. Then, Ni can be recovered from the biomass of these hyperaccumulator plants. Agromining is a chain consisting in growing such plants and producing metal. It has been developed thanks to the combined know-how of agronomy and hydrometallurgy. Hydrometallurgical processes have been designed; two different pathways were developed: i) acid leaching of ashes after biomass combustion and ii) direct Ni water extraction after biomass grinding. Experiments with 2 species of Ni hyperaccumulators (A. murale from the Balkans and R. bengalensis from Malaysia) have shown that the first process is very robust and transposable. For the second one, the way Ni is stored in the plant has a strong influence on extraction. A. murale transformation was explored in more details from the lab scale to the pilot scale. Results proved that Ni is totally transferred into the aqueous phase after 2 hours at 90 °C. A life cycle assessment has clearly shown the environmental interest of this approach (especially by detoxifying agricultural soils). INTRODUCTION Agromining is an emerging phytotechnology aiming at recovering metals thanks to hyperaccumulating plants (van der Ent et al., 2018). These plants are able to accumulate very high concentrations of metal in their aerial parts. For example, for nickel, the hyperaccumulation threshold is 0.1%, i.e. 10 grams of metal per kilogram of dry biomass. There are some advantages to use this technology instead of conventional mining techniques: •,Treating unconventional metal resources: they can be (i) natural soils with low concentrations but also low fertility because of the metal presence (like serpentine soils for Ni) (Bani et al., 2015), (ii) mine tailings or (iii) industrial wastes (like surface treatment sludge) after soil construction (Rue, 2017);"

Jan 1, 2018

By A. I. Urvanzev, N. V. Shikhov

"In this paper, we present the study’s results of electrical separation processes on the basis of new separator designs, new technological solutions, and newly discovered effects. We considered the options of enrichment by magnet separation of magnetite and titanomagnetite ores, ores and products containing chromium and manganese, ores of non-ferrous and precious metals. During pneumo-electric separation of mixed iron ore of SMPC, 43.3% of the output of the concentrate with an iron content of 61.7% was obtained in one step, with extraction of 70.5%. The paper also presents the results of the finalization on the air-electric separator of the magnetic fraction when separating oxidized ores of MPPOO (mining and processing plant of oxidized ores) on the Jans polygrade magnetic separator. A concentrate was obtained with an iron content of 65.1% with the extraction of 95.0% and tails with an iron content of 13.0%. The possibility of obtaining low-silica concentrates from these ores with an iron content of 67.15 and a quartz of 2.88% is shown. Also, the results of tests on the enrichment of chromite ores on the firing-magnetic scheme with corona-electrostatic separation are considered. On the initial ore of the Don MPP (mining and processing plant), a concentrate with a content of 61.8% Cr2O3 was obtained with a quartz content of ~ 1.0%. The results of pneumo-electric separation with triboelectric charge of the separated particles are presented. The results of the tests indicate a principal possibility of enriching chromite ores without costly high-temperature roasting. Dry technology of enrichment of manganese ores with the use of electrical separation increases the quality of the oxidized concentrate to the first grade and raises the total extraction by 2 times. For the Chineya deposit of titanomagnetite ores with copper impurities, electroseparation operations were carried out on two samples with a Cu content of 1.93 and 3.75%, respectively. For a sample with a Cu content of 6.02%, a copper concentrate output of 24.42% was obtained with a Cu content of 23.82% and the extraction of 94.88%. The results of enrichment by electroseparation of gold-containing sulfide ores can have the practical importance. For ores of the Berezovskoye deposit, a pyritic concentrate containing 100 g / t of gold was obtained after two or three operations of IES (integrated energy systems)."

Jan 1, 2018

By Jochen Petersen, David G. Dixon

"Although heap leaching may be perceived as a somewhat low-tech route for the extraction of low-grade minerals, the underlying physical, chemical and biological processes are in fact extremely complex. There has been increased interest in heap leaching of sulphide minerals in recent years with the advent of controlled bio-heap leaching, and the need to mine more marginal ore deposits.A detailed investigation into the dynamics of heap leach processes has provided much insight into the underlying complexities, and has led to the development of a sophisticated modelling tool. Some of the features include mineral kinetics, particle level effects, bacterial growth, oxidation and adsorption, gas adsorption, pore diffusion, bulk advection, gas balance and heat conservation.Two case studies are presented which illustrate specific features of the model for different applications and how these have helped to identify key areas of concern. In each case the model has proved as an invaluable tool either for the improvement of existing heap leach practice or for the development and assessment of novel applications."

Jan 1, 2003

By E. N. Levchenko, K. V. Bulatov, G. I. Gazaleeva

"The article highlights the new procedure of choosing special methods of disintegration for very complicated rare ores. Especially, there is a complex approach to criteria of comparing different types of crashing machines. Criteria are as follows: degree of crashing, degree of grinding, degree of slime creation and the new creations criteria for selection. The procedure is tested on tantalium and zelestinium ore. A new methods was shown the preference impact crashing machine MD-7 for zelestinium ore. In product of crashing 0,050 mm size are 9.4 %, 0,005 mm size – 2.5 %.This is gut result, and show the best indexes of slime creation. The check of the proposed new methods was done when comparing the crushing of tantalium ores of the Otboynoe deposit in cone inertial and centrifugal impact crushers and roller press. A research was conducted different crashing machines under laboratory and semi-industrial conditions. Different operation modes of crushers were also checked. The comparison of the crushing selectivity criterion and degree of crashing showed that the centrifugal impact crusher (CC) and roller press (RP) has the lower indexes than the cone inertial crusher (CIC). Degrees of crashing for different crashing machines are:centrifugal impact crusher – 10.1;roller press – 10.8;cone inertial crusher – 14.2. The crusher CC the selection criterion is 0,632 units, RP – 0.730, where as for the crusher CIC – 0.848 units. The best crushing mode for the crusher CIC-300? is as follows: turning angle of debalance is 0°, peripheral speed of a cone rotation – 1420 r.p.m, specific energy consumption- 4.99 kW*t/t. Crusher CIC-300? is the best for tantalium ores of the Otboynoe deposit. The new methodic are verification.INTRODUCTION Rare metal concentration circuits are complex, energy-intensive, and costly. The reasons for this include the multimetal nature of the rare metal ores, their volatile material composition and low grade. That is why careful selection of ore preparation circuits is of great importance for minimizing the energy inputs and maximizing the liberation of the valuable minerals. Recent research (Khopunov, 2011, Gazaleeva, 2015) has demonstrated that the most efficient comminution processes available to the mineral processing industry are selective disintegration, crushing and grinding, allowing to liberate the mineral particles along the cleavage in the comminution process. These methods are indispensable for the processing of finely disseminated refractory ores prone to slime formation. Many rare metal ores found in Russia are of this type."

Jan 1, 2018

By Reinol Compañero, Ivy Gonzales, Herman Mendoza, Brian Buenaventura

"The extraction of gold in the Philippines has been a significant challenge for the past decades. Around 70-75% of gold mined in the country can be accounted from the small-scale mining industry which primarily use the traditional cyanidation and amalgamation; processes which have been advocated due to its adverse affects to health and environment. To address this challenge, an alternative clean and sustainable technology was developed for the small-scale miners to recover gold and other metal/mineral values efficiently from Philippine ores. An initial survey was conducted and followed through with extensive mineralogical investigations ascertain the best method applicable. It was determined that Philippine gold occur in ore as (1) very fine particles in the microns range, (2) free-milling, which is in abundance, and (3) locked particles with sulfides --- it was concluded that enhanced gravity concentration and flotation are viable alternatives. A comprehensive test regime was followed to check the response of the ores obtained from different small-scale mining districts across the country. It was shown conclusively that the gold ores respond positively, with recoveries using gravity concentration and flotation of at least 95% and 88%, respectively; exceeding the nominal recoveries using cyanidation or amalgamation. A specific process flow was designed for each type of ore with customized parameters. It was determined that while capital expenditure of implementing these alternative processes is higher than what is currently being used, the operational aspects show that it is much more economical to apply enhanced gravity and flotation. It should be noted that the process developed addresses the critical issue of environmental costs which should be more than enough to justify the shift from the current to the novel and sustainable technologies."

Jan 1, 2014