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By Z. B. Pan

The innovative point of this new technology can be described that under normal pressure and 70°C, using a new combined activating and oxidizing agent, the minerals bearing arsenic and organic carbon are oxidized effectively. This technology can be applied in commercial scale. The high carbon and arsenic bearing gold ore is taken from Gansu, where hundreds of tons gold deposit. The ore has 0.51% of arsenic and 1.75% of carbon (1.07% of organic carbon). The gold occurs mainly in native with particle size 0.02~0.6 mm and a few are enwrapped by pyrite and arsenopyrite. The traditional cyanide leaching process gains a very low gold leaching rate with only 5%. Through systemic experimental study, the technological flowsheet of flotation process for concentrating gold, then pre-treating the gold concentrate followed by cyanide leaching the gold concentrate are used. With 4.92 g/t gold of head sample, the gold concentrate with 46.52g/t gold grade and 96.53% gold recovery is gained by flotation process. Followed by pre-treatment for 6 hours, the gold concentrate is leached with cyanide after filtration and washing. The total gold leaching rate is up to 95.44%.

Jan 1, 2014

By W. X. Yin

Electrowinning of lead from aqueous solution of PbCl2 and electrowinning of manganese dioxide from aqueous solution of MnCl2 are two research focuses in hydrometallurgy. This paper investigated a new process of simultaneous electrowinning of lead and manganese dioxide in chloride medium. The simultaneous electrowinning process in chloride solution not only can prevent chloride from liberating at anodes but also obtain two electrolysis products and decrease electric energy consumption. Diaphragm cell is used in the simultaneous electrowinning process to form separate anode and cathode compartment. The effects of temperature, HCl concentration in anolyte, NaCl concentration in catholyte and electrolysis time on current efficiency and cell voltage are studied. The results indicate that current efficiency of anode and cathode for 5 hours is 99% and 96% respectively, average cell voltage is 1. 701V, the weight ratio of lead and manganese dioxide produced at electrodes is 2. 39:1 under the optimum conditions. As anode products, manganese dioxide is ??MnO2, content of which in the products is more than 92%.

Jan 1, 2014

The present work aimed to verify the possibility of using froth flotation to separate the constitu-ent minerals of an alaskite rock waste having as the main minerals quartz and feldspar. Three stages of tests have been carried through. In the first stage was used an amphoteric collector for flotation, diaminedioleate, at pH 2 and, after analyzing the final products, a very poor selectivity was ob-served. During the second stage of tests, different collectors that are normally used for feldspar flo-tation as amines, sulfonates and soybean oil were employed. Once more, it was not possible to reach reasonably selective results. In the third stage, a salt of etheramine was used for collecting the feldspar and hydrofluoric acid was utilized for controlling the pH. A simulation of three flotation steps (rougher, cleaner and recleaner) permitted to attain a good selectivity in the flotation process. A concentrate with a silica content of 96.6% was obtained. The low concentrate content of alkalis totalizing 0.52% and a feldspar recovery of 96.5% to the tailings, represented by the high content of Na, K, and Al2O3 in the tailings, demonstrated that the concentrate was made up mostly of quartz.

Jan 1, 2014

By Yonghui Hu, Hongxiang Ran, Honggang Wei

"A new PVM vertical ring high-gradient high-intensity permanent magnetic separator authorized by China Invention Patent ZL201110294866.4, which featured with vertical magnetic field structure was developed to dramatically save energy consumption and running costs compared with electromagnetic separators. The specific magnetic circuit design ensures PVM separator generating high magnetic field intensity as well as solving equipment large-scaling. The newly developed industrial PVM separator has been proved suitable for recovery of weak magnetic minerals or purification of non-metallic minerals benefiting from its high background and induction magnetic field intensity up to 0.8/1.5T, stable service performance and low running costs. The first ?1.5mm PVM separator has been applied in removing iron from quartz sand in Fengyang, Anhui, and ?2mm PVM separator will be installed to separate hematite. Industrial applications and tests proved that PVM separators could gain similar separation effects and especially save more than 80% of power consumption compared with the conventional electromagnetic high-gradient high-intensity magnetic separator, which will contribute a lot for energy conservation and environmental protection. The development of high gradient magnetic separator technology has played an important role in utilizing weak magnetic minerals, which has been widely used in many mining enterprises. The main forms of high-gradient magnetic separators include both of electromagnetic high-gradient and permanent magnetic high-gradient. The vertical ring high-gradient high-intensity permanent magnetic separator features with high magnetic field gradient, large processing capacity and never clogging, which has been widely used in recovering fine weak magnetic mineral and purification of non-metallic minerals[1-3]. However, electromagnetic coils excitation needs more energy consumption, and relatively high running costs and maintenance costs as a result of the complicated cooling system. So permanent magnetization of the electromagnetic magnetic separation equipment is a very important research direction at present. With the continuous improvement of resource utilization standard and efficiency requirements, high energy consumption of the electromagnetic vertical ring magnetic separator have been highlighted, which has affected the economic benefits of mining enterprises to a certain extent. In the aspect of high-gradient high-intensity permanent magnetic separation equipment, considerable researches have been carried out at home and abroad and many small-sized prototypes were developed yet never strode into large-scale industry applications[4-6]."

Jan 1, 2018

By D. Moradkhani

The heap leaching of oxide copper ores with copper cathode recovery by solvent extraction and electrowinning is now well established as a low-cost method of copper recovery. The main purpose of this study was to extract copper from the copper low-grade oxide ore of Chodarchaei mine using column leaching. The copper oxide ore contained 1.1% Cu and 1.75% Fe. The mineralogical analysis indicated the malachite (Cu2(OH)2CO3) was mainly composed of oxidized phases. The sulfuric acid leaching experiments were performed under the laboratory conditions. The influence of several parameters on the course of the reaction such as particle size, acid concentration, flow rate, and time was examined. The optimum collective extraction of copper and iron was obtained at a particle size of +10-15 mm for a leaching duration of 3 days with sulfuric acid concentration of 100 gpl and using a flow rate of 2.5 cc/min. Under these conditions, the recovery of copper and iron were 98.54% and 41.99%, respectively. Keywords: column leaching, copper, iron, working diagram.

Sep 1, 2012

By P. K. Fedotov

Centrifugal separation opens its new application fields in the Mining Industry. The up-to-date equipment for ultra-fine ore and concentrates grinding allows an efficient use of centrifugal concentration for micronic gold grains recovery. Moreover, advanced centrifugal concentrators are presented on the market: concentrators with continuous concentrate discharge designed both for ore and non-metallic minerals concentration process. The conducted tests proved the centrifugal concentration to be efficient process for gold recovery from finely ground concentrates and ores (less than 20 µm). Knelson concentrator application for such a fine material in different process circuits makes possible to raise the total gold recovery level of plants. In the circuits of coal plants and in course of coal slimes treatment the centrifugal concentration may be used before flotation in order to improve process performances. A centrifugal concentrator KC-CVD with continuous concentrate discharge working on 0.3 (0.5)mm fraction before flotation is

Jan 1, 2014

By Ashiwani Kr Gupta

The floatability of coal is affected by the presence of dissolved inorganic ions in plant process water. Water quality is characterized in terms of conductivity, hardness, turbidity and composition of oil. These quality indices are correlated with coal flotation performance for three different water named, ?R&D laboratory tap water?, ?process untreated water? from West Bokaro wahsey-2 Tata Steel, India and ?process treated water? after passing laboratory developed treatment process. The study clearly indicated that a significant quantity of clean coal is being lost due to poor process water quality used in the flotation process. The laboratory investigations showed that if these dissolved salts and suspended solids are reduced to even 50%, a clean coal yield improvement by minimum 5%~10% at the same ash level could be expected. Therefore, the conventional practice of water recycling though a thickener or a tailings pond needs a complete re-look. The water treatment process for recycled water has also been discussed for improving the process water quality as well as enhancement in flotation performance efficiency.

Jan 1, 2014

By C. Abbruzzese, F. Vegliò, S. Ubaldini, R. Massidda

The aim of this paper was to study the influence of different water/organic solvent mixtures (isopropyl alcohol, ethanol and ethylene glycol) on the gold desorption process. The experimental work was carried out on laboratory scale, using activated coconut carbon with different temperatures and extraction times, without adding cyanide. Best results have been obtained in this order: isopropyl alcohol > ethylene glycol > ethanol. Starting from gold concentration of about 5 g Au per kg of carbon, best kinetics resulted in 97-100% of gold extraction, after 8 hours of desorption, at a temperature of 80ºC.

Jan 1, 2003

By N. R. Mandre

In the present work an attempt has been made to study beneficiation of low-grade iron ore associated with manganese clay by selective flocculation. The representative samples obtained for this purpose were initially subjected to chemical and mineralogical studies. The chemical analyses indicated 42.56 % Fe, 6.25% Mn, 8.72 % SiO2 and 13.60 % Al2O3 in the representative sample. The mineralogical analyses carried out under optical microscope showed that the ore mineral predominantly comprised of iron oxides and hydroxides along with manganese and silicate as gangue minerals. Prior to the beneficiation studies, the samples were subjected to settling tests. These tests were carried out by using poly acrylic acid (paa), poly acryl amide (pam) and guar gum (gg) as the flocculants. From these studies it was observed that settling rate of particles increases with increase in pH and a maximum settling rate of 0.23 cm/secwas obtained at pH 9 in presence of poly acryl amide. Further, the samples were subjected to selective flocculation studies using above-mentioned reagents. From these studies better results were obtained in the experiments carried out with poly acryl amide as the flocculant. Thus, it was possible to upgrade the iron content from 42.5 to 53%, with a recovery of 92%. However, 51% Fe with recovery of 87% and 50% Fe with recovery of 94 % was obtained using poly acrylic acid and guar gum respectively.

Sep 1, 2012

By A. Yörükoglu

In this study, thorium mineral that found in the complex ore deposit bearing bastnasite, fluorite, and barite from Eskisehir - Sivrihisar district has been tried to extract by using HCl and H2SO4 leaching. Ore sample of approximately 3 tons taken from the ore deposit has been homogenized in order to obtain composite samples by means of ore preparation techniques for experiments. Results of chemical analyses of composite samples are as given; 40.8% CaF2, 35.35% BaSO4, 2.01 Ce, 1.5% La, 0.39% and 0.1% Th. HCl and H2SO4 leaching processes have been performed to gain Th in the ore. For determining the optimum particle size, the samples have been ground under controlled conditions and brought to the sizes of 0.065, 0.2, 1 and 3 mm. Leaching experiments have been carried out in both HCl and H2SO4 acids without roasting and roasting at the temperature of 900°C for 1, 3 and 6 h retention times for all particle sizes determined before. In the experiments, the highest Th recoveries reached are as follows; 78.74% Th when H2SO4 and 1 mm particle sized sample used, and 1 h roasting applied and 73.38% Th when HCl and 1 mm particle sized sample used, and 3 h roasting applied. Keywords: thorium, leaching, concentration, sivrihisar, roasting

Sep 1, 2012

By F. Burat

At the present time, methods of mining and coal preparation produce tones of coal fines. The removal of water from these fines is necessary for economical and technological reasons. Supplementary processes that utilize different physical and chemical methods have been developed to in-crease the productivity of mechanical dewatering processes. Researches have shown that chemical reagents used along with conventional systems diminish moisture and increase the capacity and the yields of the dewatering method. In this study, the parameters of the vibrating screen (incline, frequency, feeding rate and screen size), the effects of the application of additional vertical mechanical vibration and surface active reagents (CTAB, SDS, Umectante B-70 and Kerosene) were investigated. At the end of the optimization experiments, 61.0% moisture was decreased to 42.3%. By keeping optimum conditions con-stant, the experiments have been conducted to determine most effective reagent. 41.2% moisture has been obtained with 5 g/t CTAB at the normal pH of the pulp, which were 7.25. By using vibrating screen with combination of the vertical vibrating mechanism, CTAB gave the best result of 40.7% moisture. Finally, the effect of increased surface area of the screen has been investigated and de-creased the moisture level to 38.7%.

Jan 1, 2014

By X. L. Song

A large amount of tailings in concentrators bring a series of problems to the environment and society. It is significant to reclaim the huge tailings and reuse them in industries in order to utilize mineral resources adequately. Primarily Lead-Zinc tailings with a certain quality of clay and feldspar were used to produce ceramic tiles by sintering method under specific technical conditions. By testing the properties of the ceramic tiles, it was shown that the amount of Lead-Zinc tailing used in the tiles was 60%~70%, and the mechanics properties were good. The optimum proportion parameters were Lead-Zinc tailing 60%, clay 35%, feldspar 5%, and the maximum flexural strength of tiles was up to 38.2MPa when it was sintered at 1090? for 30min. Its flexural strength, water absorption and thermal shock resistance reached the State Standard of GB/T4100.4. The product is suitable to be used in pavements and paths of parks.

Jan 1, 2014

By M. Paymardi, A. Foroutan, T. P. Oladele, M. Abbaszadeh

"Reducing the amount of zinc and iron in lead concentrate is one of the important aspects of processing in lead and zinc flotation plants which results in improvement of lead concentrate quality and prevents zinc loss. In mineral flotation industries, lignin sulfonates are known for their depressant properties for both non-metallic and sulfide minerals such as pyrite and pyrrhotite.This paper investigates the effect of lignin sulfonate on flotation of galena, sphalerite and pyrite in sulfidic lead and zinc bearing ores. Batch flotation tests were carried out on a high pre-activated zinc samples. The feed contains 0.9% lead, 2.3% zinc and 7.5% iron. The dosage of all reagents such as sodium cyanide, zinc sulfate, ethyl xanthate and methyl isobutyl carbinol (MIBC) were kept constant for lead flotation step except calcium lignin sulfonate (CLS) that was varied between 0 and 80 gr/ton.Results for lead rougher concentrate showed that the grade of lead increased by 2.7% while the recovery decreased around 4 % at the highest dosage of CLS. Furthermore, zinc recovery decreased by 6.3% with no significant change in grade. Iron recovery in lead rougher concentrate decreased by 2.3 % while the grade changed around 1%. In sphalerite flotation step, CLS dosage was changed in the range of 0 to 80 gr/ton while the dosage of other reagents such as copper sulfate, lime, amil xanthate and MIBC were kept constant. In this step, no decreasing in grade and recovery of zinc was observed, while iron recovery decreased. It was suggested that CLS has a depression effect on sphalerite in conjunction with other zinc depressants such as zinc sulfate and sodium cyanide. CLS was further used in plant with non-pre-activated zinc minerals. Similar trends were observed in plant.INTRODUCTIONlead-zinc sulfide minerals play an important role in the production of lead and zinc metals in the mineral processing industry (Luo, Feng et al. 2016). Due to complexity of the lead-zinc ores mineralogy, in some situations, their flotation properties vary significantly from one deposit to another one even in itself (Bulatovic 2007)."

Jan 1, 2018

By G. J. Feng

Based on detailed theoretical analysis of coarse floatation and three-phase froth, a laboratory system which contains a new type of froth floatation equipment is established. Through water experiment, the relationship among floatation dynamics parameters of the equipment is studied and the best work parameters are educed too. Based on all of above, Slurry test is carried out in a copper concentration plant. Granule between 0.28~0.45mm can be reclaimed successfully. The slurry test proves that to separate coarse minerals in froth floatation equipment is a kind of effective method, it is well worth to make a further study.

Jan 1, 2014

By A. P. Das

Biomining technology focuses on achieving effective recovery of precious metals from their ores and concentrates using microbial techniques. Biomineral extraction of manganese from low-grade manganese ores using bioleaching was investigated in this paper. Five fungal strains were selected for screening of bioleaching of low-grade Mn ore collected from Sanindpur iron and manganese mines, Koira Sector, Keonjhar, Odisha, India. A fungal strain, Aspergillus niger was selected as it showed high efficiency of manganese leaching. Growth of the fungus was determined in terms of sbiomass dry weight and the final pH was monitored. The selected fungal strain was used for bioleaching of low-grade manganese ore of -150µm size particle size at 2 % pulp density with 2g/100ml sucrose concentration for duration of 20 days. About 60 % of Mn bioleaching was obtained with A. niger. The fungal species proved to be useful for manganese biomining.

Sep 1, 2012

By Thi Hien Tran, Huy Hoan Nguyen, Thi Thu Hien-Dinh, Hong Son Nguyen, Duy Anh Dao

"Lithium discovered in La Vi deposit, Quang Ngai province in the Central of Vietnam was estimated with a reserve of approximately 1.5 million tones of lithium ore, which was characterized by mainly lepidolite with muscovite, albite, and quartz. This study investigated reasonable flowsheet and optimal conditions of enrichment technology for lepidolite from the mined ore by flotation process, and producing Li2CO3 and LiCl from lepidolite concentrate by hydrometallurgical process. The significant conditions for froth flotation of lithium ore including particle size, pH of ore slurry, pulp density, chemical spending (collectors, activators, depressants, and frothers), stirring and flotation time were investigated. The identified reasonable flowsheet and optimal conditions for froth flotation the La Vi lithium ore processed lepidolite concentrate containing up to 4 wt.% Li2O with a recovery of 87.61 wt.%. The processes of sulfation roasting lepidolite concentrate using FeSO4.7H2O, then leaching in H2SO4 solution, and removing impurities were carried out to prepare a pure lithium-bearing solution for producing Li2CO3 and LiCl. The products containing 99.05 wt.% of Li2CO3 and 99.02 wt.% of LiCl were obtained with recoveries of 82.97 wt.% and 85.77 wt.%, respectively. The obtained results indicated that lithium ore in La Vi deposit can be processed to produce commercial lithium products and lead the study to develop technology for a new industry of lithium processing in Vietnam.INTRODUCTION Lithium is the lightest metal, which has many superior properties in both metal and compound (such as Li2CO3, LiCl...) states since its discovery in 1817 by Swedish chemist Johan August Arfwedson. Lithium is a favourable material for many high technology fields such as aerospace industry and chemical industry. Some industrial fields which present the main consumptions of lithium include ceramic, glass, aluminum alloy, lubricants, rechargeable Li-ion batteries, synthetic rubber, and pharmaceuticals. The worldwide production of lithium in 2014 was 31,700 tones, continually increased in 2015 of 5% presented 32,500 tones (USGS, 2016). The demand for lithium tends to increase because of the raising in consumption of lithium batteries. Lithium is mined from salar brines, mainly in Chile and Bolivia, but also from granites and pegmatites, which contain minerals with high lithium content such as spodumene - LiAlSi2O6 (Heinrich et al., 1978; Linnen et al., 2012); petalite - LiAlSi4O10 (Sitando & Crouse, 2012); zinnwaldite - KLiFe2+Al(AlSi3O10)(F,OH)2 (Paukov et al., 2010; Kondás J. & Jandová J., 2006); lepidolite - K(Li,Al)3(Si,Al)4O10(F,OH)2 (Luong et al., 2013); and amblygonite - LiAlPO4F (Garrett, 2004)."

Jan 1, 2018

By G. Kumar

Water for domestic consumption is an essential right of society, which must be over secured. Water reclamation and reuse provides a unique and viable opportunity to augment traditional water supplies. As a multi-discipline and important element of water resource development and management, water reuse can help to close the loop between water supply and wastewater disposal. Effective water reuse requires integration of water and reclaimed water supply functions. During the coal mining activities, large quantities of water get contaminated and loses its potability characteristics. On an average, in coal mine operation, each coal mine discharges effluents at a rate of nearly 0.5 MGD and thereby wastage of nearly 50 MGD of water takes place per day from the famous Jharia Coal Field of the Dhanbad District. In this paper, attempt has been made to control the extremely high turbidity of mine waste water by using different coagulants and it is observed that ferrous sulphate is the most effective coagulants followed by alum, ferric sulphate and lime. Also combinations of coagulants are used for getting the optimal results. Further steps were also discussed to make this water potable and a scheme of low cost water supply system of mine waste water has been suggested under the Water Management Strategies. Keywords: potability, turbidity, coagulants, water management strategies

Sep 1, 2012

By R. X. Li

The overall flow-sheet of producing chromium (III) sulfate is described in this paper. The suitable conditions of each process such as sintering, leaching, aluminum removal, reduction, and de-composition conditions were experimentally studied. The results show it is reasonable to produce chromium (III) sulfate with the flow-sheet pointed out in this research work. The final product is Cr2(SO4)3 solution contained 150~250g/L Cr.

Jan 1, 2014

By Q. W. Jiang

This paper presents a new process for producing industrial magnesium sulphate using waste water from titanium white plant and magnesium oxide from calcinations of magnesite ore as raw materials. With the laboratory experimental equipment, the waste liquid and magnesium dioxide react effectively at ambient temperature and under atmosphere pressure. Via the press filter, a clear liquid predominately containing magnesium sulphate is obtained. It is further evaporated and crystallized by cooling, separated by centrifuge and dried. Consequently a high quality of industrial magnesium sulphate is achieved as the final product. In the course of process, as the majority of valuable component (SO42-) is recovered in the final product, most of impurities from waste acid is being removed into the by- product. With the simple operational process, it is possible for titanium dioxide plant to resolve the environmental problem completely and benefit from the industrial magnesium sulphate product as well. The filter cakes containing valuable elements such as Mg, S, Fe, Mn, V, Ti are by-product proposed to be used for manufacture of agriculture fertilizer particularly for peanut planting.

Jan 1, 2014

By T. Gong

Often plans to increase plant throughput provide an opportunity for optimising plant equipment and operating methods. This was the case in 2005 at TISCO Jianshan Iron Mine, when an increase in production was planned. The thickening circuit had presented a limitation to the plant throughput and operation with poor overflow clarity and underflow density. Following a course of test work by Outotec, a 53m diameter Supaflo® High Rate Thickener (HRT) was selected for the duty. From early stages of operation of the new thickener, the benefits have been dramatic, including: ? Improved tailings underflow density by 9% ? Improved Overflow clarity to less than 150ppm ? Considerably decreased the water and energy consumption as well as operation cost ? Stable and reliable operation This paper looks at this installation as a case study and compares the previous thickener installa-tion performance with the performance of the single 53m HRT.

Jan 1, 2014