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By Song Z. Guo

Calcite and magnesite are both carbonate minerals and their crystals belong to trigonal system. Flotation tests were carried out to investigate the flotation behaviors of calcite and magnesite. The test results show that the floatability of calcite and magnesite under different grinding environment had obvious differences. The floatability of calcite using sodium oleate as collector after dry grinding is better than wet grinding, but the floatability of magnesite after wet grinding is better than dry grinding. The XPS surface elements test and zeta potential measurement show that, wet and dry grinding process makes the distribution difference of surface anion and metal cation, then influence the floatability of the two carbonate minerals using sodium oleate as collector. Difference of the carbonate crystal structure and solubility properties was also investigated. Research shows that crystal structure difference of calcite and magnesite causes the difference of solubility, which can influence the flotation behaviors under different grinding environment. Keywords: carbonate mineral, crystal structure, solubility properties, flotation, surface character

Sep 1, 2012

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 Kwang Soon Moon

Liquid ? liquid reactions such as solvent extraction in hydrometallurgy and BTX extraction in petrochemical industry has long suffered from the long retention time mainly due to the limited interfacial area caused by the immiscibility between water and oil phase, requiring typically very large perfect mixer type reactors and tall adsorption towers. A novel spray reactor for immiscible liquids; that is the KISEI Nozzle Reactor (KNR) was introduced, enabling the drastic increase in the interfacial area between the reacting immiscible liquids. Various spray mechanisms were applied in materials processing, e.g. spray drying, powder metallurgy, and aerosol industry, but not in hydrometallurgy. The KISEI Nozzle Reactor(KNR) was fully developed and used in production of biodiesel from the immiscible triglycerides and methanol. An experience with a full production plant facility is briefly discussed in the current paper. With the fog-like methanol spray in oil medium, the trans esterification reaction was almost instantaneous, and transformed the traditional batch trans esterification process into a continuous production process. And above all, with no moving parts in the KISEI Nozzle Reactor (KNR), the process requires minimal operation and maintenance costs. Keywords: immiscible liquids reaction, nozzle spray reactor, continuous biodiesel reactor, hydrometallurgy, organic extraction, micro emulsion

Sep 1, 2012

By M. Q. Xu

During the flowsheet development for a potential commercial Cu/Ni separation plant at the In-co?s Sudbury operation, extensive laboratory and miniplant studies were carried out. There are two potential feed streams for Cu/Ni separation at the existing operation. It is shown that Cu/Ni separation from the rougher concentrate is relatively simple without need of regrind. However, Cu/Ni separation can be difficult from the bulk concentrate because of the presence of excess flotation reagents in the bulk concentrate slurry and locked particles. Excess flotation reagents created excess froth increasing entrainment. By replacing the slurry water with tap water and with addition of some hydrogen peroxide, entrainment is minimized and good Cu/Ni separation is achieved on the bulk concentrate. Fine regrind is required to increase liberation of the locked particles for ultimately high copper recovery at the minimal nickel content.

Jan 1, 2014

By A. I. Arol

Bentonite is an important industrial mineral with very wide application areas. Its unique colloidal, swelling, thickening and adsorption properties make it a useful agent in drilling, metal casting, and iron ore pelletizing, environmental, food, cosmetics, pharmaceuticals and many more industries. Because of its swelling property, bentonite suspensions can only be prepared at rather low solid coentrations, i.e. 8-10%. In order to process bentonite in slurries with high solid content, it was thought that a non-polar organic solvent, instead of water, can be used. Not only large amounts of bentonite can be dispersed in organic solvents but also the solvents may be regenerated. The bentonite obtained through such a process must either equal or better properties than those of untreated bentonite. In this study, the effect of organic solvents such as acetone, methyl-ethyl ketone and n-haxane on the main properties of bentonite, such as water adsorption and rheology, was investigated. It was found that bentonite can be dispersed in the mentioned organics in large quantities with no loss of quality. Keywords: bentonite, montmorillonite, water adsorption, industrial minerals

Sep 1, 2012

By Yuhe Tang

High Gradient Magnetic Separator with Horizontal Magnetic Line is a new type High Gradient Magnetic Separator product. It has many specific advantages, such as water-air joint discharging technique, double pulses pulp dispersion technique, multi-magnetic gradient for collecting matrix with different diameter rods, better discharging rate with the especial matrix dispose, high separating accuracy and wide applicability. In this paper, the author makes a description of High Gradient Magnetic Separator with Horizontal Magnetic Line, and puts its emphasis on analyzing industrial production data using high gradient magnetic separator with Horizontal Magnetic Line to separate weakly magnetic minerals. It is found that as the rougher for weakly magnetic minerals separation, High Gradient Magnetic Separator with Horizontal Magnetic Line has more stable metallurgical performance and cheaper running costs than other types of High Gradient Magnetic Separator when the properties of the ore change greatly and there is in the case of embedded fine particle size distribution. Keywords: high gradient magnetic separator, self cleaning technology, horizontal magnetic line, water air discharging technique

Sep 1, 2012

By X. M. Yu

A large amount of polluted sludge is produced by a nonferrous metal factory after treating waste water with lime/ferrous salt. The concentration of arsenic in the dried sludge is high to 5.84%, a toxicity test is taken on the sludge according to GB5085.3-2007 and the extraction content is 15.75mg/L, which surpasses the arsenic extraction standard [As]=5mg/L, the sludge is categorized as hazardous waste. If put outside without disposal, it would be very harmful to environments. Here we report an optimum protocol to extract arsenic; S2- alkaline liquor is utilized to treat the arsenic sludge. At 85?, 10L 7% S2- liquor is added into 1kg dried sludge and the resulting mixture is stirred for 120min at 250r/min, then separated by centrifugation and the compressed waste residue dried naturally. The average arsenic content is 1.40mg/L, lower than GB5085.3-2007 Standard and arsenic-free residue is consistent with GB18598-2001 Standard, which can be bury safely. The extracted arsenic is transferred into copper arsensite for use as addictive in copper electrolysis and the waste water can be recycle after calcium is removed.

Jan 1, 2014

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 P. Holtzhausen, L. Auret, B. Lindner, A. Haasbroek

"Spiral concentrators offer a cost effective way to separate valuable minerals from gangue by displacing lighter materials to the outside, and heavier materials to the inside of the spiral. The separation can be seen as visible concentrate bands and splitters are set at the bottom of the spiral to effectively split the ore into various densities. As there are typically many spirals in a concentrator plant, it becomes ineffective to continually adjust the splitter positions manually. Vermaak et al. (2008) proposed to use image recognition to detect the concentrate bands, thereafter, creating a model predicting the positions under certain input conditions. This model could then be used for optimisation and/or control of splitter position or band position. In contrast an online concentrate band detection system would provide real time concentrate band positions without losing accuracy due to model generalisation. These systems are usually expensive and time consuming to develop, due to a lot of centralised features required (image capturing, image processing and/or feedback to a controller). This study took advantage of the recently developed Raspberry Pi minicomputer to perform rapid prototyping of an online image processing sensor. The Raspberry Pi, and accompanying camera module, offers a portable Linux environment which can natively run the required image processing algorithms. Furthermore, extensive use of OpenCV was made to reduce development time, by relying on existing and proven algorithms to detect the concentrate bands. The Raspberry Pi also incorporates generic input/output ports which can be used in future work to provide the signal to a controller. In conclusion, the Raspberry Pi was successfully used to perform real time concentrate band position detection on a spiral concentrator. This solution is more general than an experimentally identified input-output model and may be used for control or optimisation studies in a wide array of spiral concentrators."

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 P. K. Arya

Huge quantity of copper is lost in Crown, Sill, Rib Pillars, hanging wall, foot wall and unexploited ore bodies in several closed underground copper mines and old worked out stopes of Hindustan Copper Limited at Mosaboni and other places. These mines might have been uneconomical to work with conventional mining methods. However, huge quantity of mineral reserves is lost due to their closure. Chemical and in-situ bio-wash leaching, if tried can provide an answer to facilitate the recovery of metallic values economically. Encouraging results were obtained during an experiment at North Badia Mines at Mosabani in the past. Though the experiments were not completed but whatever results obtained were very encouraging and can be successfully tried to make it viable. The results of the experiments are discussed here and a plan is suggested to recover copper from such mines.

Jan 1, 2014

By D. M. R. Sekhar

Certain types of rock phosphates of sedimentary origin are applied to acidic soils as fertilizer directly. Recent research in India showed that high grade rock phosphate in fine size when used as a mix with organic manure works as efficiently as di-ammonium phosphate (DAP) in alkaline soils. The rock phosphate from Jhamarkotra, India (sedimentary origin), Egypt (sedimentary origin) and South Africa (volcanic origin) showed good agronomic efficiency when used as Phosphate Rich Organic Manure (PROM). Further PROM shows equal residual effect. The results of efficiency of PROM made using two grades (+ 24% P2O5 and 34% P2O5) of rock phosphate mineral from Jordan show that low grade rock phosphate slimes are as effective as high grade phosphate concentrate when used in PROM. Also PROM is very effective in the saline soil of Eshidiya desert where DAP is not at all effective.

Jan 1, 2014

By Liu Fan, Shang Yanbo, Wang Zhongming

"Besides valuable metals of Cu, Sn, WO3, Zn, there are S, Ag, CaF2, In and so on in a complex ore deposit in south China (which belongs to Hu Nan Shizhuyuan Non-ferrous Metal Limited Liability). Although it proved reserve amounts to 3.5×107 ton, its crystal character limits its utilization in large-scale. It features complex relationships between valuable minerals, finest crystallized particle size, low-graded valuable metals (Cu 0.30%, Zn 0.5-0.7%, Sn 0.2%, W<0.1%). If only tungsten minerals are considered, it means WO3 grade is too low (the cut-off grade of WO3 is 0.1% in China). Only Cu and Sn minerals are recovered from 2006 and Cu recovery is less than 70%, Sn 15-20%. Other valuable metals of W, Zn, S and CaF2 were lost in the tailings. To make good use of the ore, the technology of fully recovering Cu, Sn, W, Zn, CaF2 and rare metals are in urgent need. After systematic researches, the flow sheet of "bulk flotation of Cu-Zn minerals at first, then Cu-Zn separation, then recovering sulphide by flotation, then recovering iron minerals by magnetic separation, then bulk flotation of Sn-W minerals after desliming" is developed. Furthermore, specific Sn-W collectors of BK411 and BK412 are applied into the processes and better indexes are obtained. The industrial indexes are listed as followings: the content of Cu, Zn, Sn, WO3 of ROM ore is 0.31%, 0.65%, 0.13%, 0.03%; Cu and Zn recovery are 82.23% and 37.79% respectively; 63.76% of Sn and 34.34% of WO3 go into the Sn-W bulk concentrates. Economic benefits are remarkable."

Jan 1, 2014

By Xuliang Yang, Yuemin Zhao, Bo Zhang, Liang Dong, Cheng Sheng, Gongmin Li, Zhenfu Luo, Yaqun He, Chenlong Duan

Coal plays an important role in the primary energy consumption of all over the world. In 2012, coal reached the highest share (29.9%) of global primary energy consumption since 1970. Coal burning mainly contributes to the emission of SO2, NOX, Hg and other impurities that jeopardize the future of environment. . Beneficiation before coal utilization is the most economical and effective technology for removing the hazardous material and gangue. In this paper, a novel process of dry beneficiation based on gas-solid two-phase flow composed of the compound dry cleaning separator (FGX), the air dense medium fluidized bed separator (ADMFB) and the vibrated fluidized bed with autogenous medium (VFB) is proposed. The main equipment and the flowsheet of the united system are described in detail. Separating principle of the FGX, ADMFB and VFB devices are all based on gas-solid two-phase flow. In FGX, gassolid suspension is composed of continuous gas flow and coal powder in feed coal. Large size coal (+6- 80mm) can be pre-separated effectively, and large size gangue can be removed effectively. Moreover, - 6mm particles fed serve as autogenous medium in FGX. The probable E value is 0.13 for -80 mm raw coal. In ADMFB, magnetic powder with -0.3 + 0.045 mm size fraction and coal powder in feed coal are compound medium solids. The separation density can be adjusted and controlled according to properties of raw coal. -50 + 6 mm raw coal can be cleaned efficiently, the probable E value is 0.05. In VFB, -6 + 1 mm coal can be separated. Generally, -80 mm raw coal can be cleaned efficiently in the united system based on gas-solid two-phase flow.

Jan 1, 2014

The flotation efficiency of magnetic concentrate of the Anhui hematite ore, which includes a great quantity of iron-bearing silicates, has been studied through reverse flotation test with a new type of collector Fly-102. The results indicate that collector Fly-102 has a strong adaptability to the variation of temperature, when the flotation temperature is in the range of 10? to 35?, using collector Fly-102 can obtain good flotation indexes. Collector Fly-102 has a strong adaptability to the variation of the slime contents and grades of the flotation samples. When the content of slime and the grade of the flotation feeds are 30% and 55.63% respectively, under the condition that the temperature is 15?, the open circuit flotation test was carried out with collector Fly-102. After one-stage roughing, one-stage cleaning and two-stage scavenging, a better result is got, the grade of iron concentrate reaches 67.12%, and the recovery of iron concentrate comes up to 84.15%.

Sep 1, 2012

By X. W. Zhang

Mica plate is broadly used in electric industry, production of man-made mica paper plate is in-creasing. The problem coming with is that large quantities of leftover materials unable to be re-cycled are produced during cutting and molding of mica plate productions. The leftover materials are always abandoned as crabs, which not only pollute the environment but also waste our resources. The study intends to find a new measure to decompose and to reuse the mica plate leftover materials so as to create a new production process of mica plate, which is clean and does not produce crabs.

Jan 1, 2014

By R. Paturi

Mill liners play an important role in the operation of a mineral concentrator influencing the throughput, availability, power drawn and the efficiency of the mill in the plant. Liners protect the shell and transfer energy to the grinding charge. Metso Technology Development has conceptualized, developed and successfully implemented physics based 3D DEM simulation techniques to predict charge motion, power drawn, energy spectra and wear over the life of the liner. This paper will present a case study of shell liner optimization for a 34? SAG mill including the input data requirements, and shell liner optimization methodology using the 3D simulations that eliminates the need for the traditional expensive and lengthy proto-type testing. These simulations will cover ball and particle movement, liner wear and mill power draw, and do not cover particle breakage and slurry flow. Even the liner manufacturers lack the ability to provide this type of qualitative and quantitative information on their products. The data from these simulations provides the plant engineers a scientific basis for their decision making and thus eliminates guess work. Keywords: liner, optimization, multi-physics, 3D-DEM

Sep 1, 2012

By X. Q. Cao

As the second largest phosphate resource in the world, Chinese phosphate ores generally grades with low of P2O5. The presentation of beneficiation test on the low grade of phosphate rock in this paper may be used for a reference for development and utilization of the similar reserves. The ore is a marine sedimentary phosphate rock containing low grade of P2O5 and high content of MgO and R2O3; The banded structure shows its suitability for heavy medium separation. The laboratory heavy liquid testing results indicate that as specific gravity of the heavy liquid is 2.85 g/cm3, a rougher concentrate assaying 28.71% P2O5 could be obtained while the rougher tailings contain only 4.47% P2O5. When the combined process with heavy liquid separation followed by direct & re-verse flotation is employed to treat the feed containing 21.15% P2O5, 3.79% MgO, 1.86% Fe2O3, 3.66% Al2O3, 23.75% A.I, and specific gravity of heavy liquid is 2.84 g/cm3, the optimum mesh of grind is 67.5% minus 200 mesh, a phosphate concentrate contained 32.51% P2O5, 0.48% MgO, 0.81% Fe2O3, 1.69% Al2O3 can be produced at a yield of 55.24%. The concentrate P2O5 recovery is 85% with which quality comply with the Class A specifications for production of phosphate fertilizer.

Jan 1, 2014

By A. K. Mukherjee

In this apparatus closed sized particles are placed in a container and then fluidized by passing water through the load of particles. Water flow is adjusted to deposit particles in one or more layers depending on the specific gravity of each of the particles, after which the deposited particles are separated in portions of different specific gravity. The obtained portions represent different ore content of the closed sized fraction. The process is repeated for all other size fractions to generate washability curve of the feed. Three different types of iron ores and one coal sample are tested in this equipment. The theoretical yield-grade curve generated for iron ore feed is unique in absence of any such practice for ore minerals. Similar curve is generated for coal and it is compared with washability curve, an existing practice followed worldwide. This comparison validates the performance of the process and the equipment.

Sep 1, 2012

By Magnus Evertsson, Haijie Li, Erik Hulthen, Mats Lindqvist

"The static and dynamic models for autogenous (AG) and semi-autogenous (SAG) mills have been studied for decades. Though the effects of mixing soft and hard ores in a mill and their interactions are not widely investigated. To develop a general numerical model for AG/SAG mills, a dynamic model has been introduced, and its capability to simulate multi component ore breakage has been examined and compared with previous publications. The simulation results show that the dynamic model can cover a range of milling conditions and is able to simulate complex scenarios with soft and hard ores. The dynamic model discussed here could provide substantial potential for the controlling and optimization of the comminution circuits. INTRODUCTION In the last decades, efforts have been devoted to studying the comminution circuit due to their high energy consumption. The energy directly spent in minerals comminution was about 2% globally in the year 2000 (Maurice et al, 2003). As one important part of the comminution process, AG/SAG mills are widely used for primary grinding in minerals processing. AG/SAG mill models include static and dynamic models (Kojovic et al, 2012; Yu et al, 2014; Yu et al, 2017; Liu and Spencer, 2004; Salazar et al, 2009). Many static models have been well validated over the past decades, but they are all based on steady state assumptions. Even though plants experience a steady-state condition under certain circumstances, it can be inaccurate to simulate the system by static models under all circumstances (Asbjörnsson et al, 2013). The advantages of a dynamic model are apparent that it provides more information and insights both inside the mill and through interactions with other machines in terms of pebble crushers, conveyor belts, screens and so on. In many mines, the multi-component grinding is inevitable, and the ratio of hard and soft components in the mill strongly affects mills operation and performance. Bueno (Bueno et al, 2010; Bueno et al, 2013) studied the effects of blending hard and soft ores in AG/SAG mills and used them to update the JKSimMet toolkit which was a steady state plant simulation software. However, due to the complexity of the particle interactions such as multi-component breakage function, appearance function, in mill transportation, there has been no dynamic AG/SAG mill models developed yet for simulating multi-component."

Jan 1, 2018