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Optimization of reagent dosages for copper flotation using statistical technique

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Transactions of Nonferrous Metals Society of China 2010年第12期20卷 2371-2378页

作者： Y.VAZIFeH e.jorjani A.BAGHeRIAN Department of Mining engineering Science and Research BranchIslamic Azad UniversityPoonakHesarakTehranIran Metallurgy Division Sungun Copper Concentrator PlantVarzaghanTabrizIran

The effects of Z11 and AP407 collectors as well as AF65 and AF70 frothers were evaluated in the rougher flotation circuit of the Sungun copper concentrator plant using 2 4 full factorial *** functions were produced for both Cu grade and recovery and optimized within the experimental *** optimum reagent dosages were found to be 12.01 g/t Z11,11 g/t AP407,3 g/t AF65 and 5 g/t AF70 to attain the maximum Cu grade(8.17%).The reagent dosages of 12 g/t Z11,11 g/t AP407,3 g/t AF65 and 15 g/t AF70 produced the maximum Cu recovery(86.44%).The collector distribution demonstrated that the distribution pattern of(32%,32%,20%,16%)can produce the best recovery(87.75%)in comparison to other examined distribution patterns.

关键词： copper sulphide ores flotation reagents modelling optimization

Prediction of operational parameters effect on coal flotation using artificial neural network

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Journal of University of Science and Technology Beijing 2008年第5期15卷 528-533页

作者： e. jorjani Sh. Mesroghli S. Chehreh Chelgani Department of Mining engineering Science and Research BranchIslamic Azad University

Artificial neural network procedures were used to predict the combustible value （i.e. 100-Ash） and combustible recovery of coal flotation concentrate in different operational conditions. The pulp density,pH,rotation rate,coal particle size,dosage of collector,frother and conditioner were used as inputs to the network. Feed-forward artificial neural networks with 5-30-2-1 and 7-10-3-1 arrangements were capable to estimate the combustible value and combustible recovery of coal flotation concentrate respectively as the outputs. Quite satisfactory correlations of 1 and 0.91 in training and testing stages for combustible value and of 1 and 0.95 in training and testing stages for combustible recovery prediction were achieved. The proposed neural network models can be used to determine the most advantageous operational conditions for the expected concentrate assay and recovery in the coal flotation process.

关键词： coal flotation operational parameters artificial neural networks combustible recovery

Prediction of yttrium, lanthanum, cerium, and neodymium leaching recovery from apatite concentrate using artificial neural networks

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Journal of University of Science and Technology Beijing 2008年第4期15卷 367-374页

作者： e. jorjani A.H. Bagherieh Sh. Mesroghli S. Chehreh Chelgani Department of Mining engineering Research and Science Campus Islamic Azad University Poonak Hesarak Tehran Iran

The assay and recovery of rare earth elements （Rees） in the leaching process is being determined using expensive analytical methods： inductively coupled plasma atomic emission spectroscopy （ICP-AeS） and inductively coupled plasma mass spectroscopy （ICP-MS）. A neural network model to predict the effects of operational variables on the lanthanum, cerium, yttrium, and neodymium recovery in the leaching of apatite concentrate is presented in this article. The effects of leaching time （10 to 40 min）, pulp densities （30% to 50%）, acid concentrations （20% to 60%）, and agitation rates （100 to 200 r/min）, were investigated and optimized on the recovery of Rees in the laboratory at a leaching temperature of 60℃. The obtained data in the laboratory optimization process were used for training and testing the neural network. The feed-forward artificial neural network with a 4-5-5-1 arrangement was capable of estimating the leaching recovery of Rees. The neural network predicted values were in good agreement with the experimental results. The correlations of R=l in training stages, and R=0.971, 0.952, 0.985, and 0.98 in testing stages were a result of Ce, Nd, La, and Y recovery prediction respectively, and these values were usually acceptable. It was shown that the proposed neural network model accurately reproduced all the effects of the operation variables, and could be used in the simulation of a leaching plant for Rees.

关键词： apatite neural networks rare earth elements leaching recovery

evaluation of Mayer curve validity on feed blending at the Zarand coal washery plant

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International Journal of Mining Science and Technology 2012年第1期22卷 19-22页

作者： Habetinejad Hamidreza jorjani esmaeil Sam Abbas Department of Mining engineering Science and Research BranchIslamic Azad University Faculty of Mineral Processing engineering Shahid Bahonar University

The coal processing methods used at the Zarand coal washery plant are the heavy medium bath,jigs,and *** coal-containing materials that are fed to the plant are acquired from different mines,and they have different washability *** this paper,the validity of Mayer curve (M-curve),the conventional method for determining coal washability,was evaluated on blending of raw coals that are fed to the *** curves were prepared for the hand-blended samples and compared with the washability predicted by the Mayer *** samples from different seams and mines were blended by hand in 50:50 ratios,and sink and float tests were performed;the resulting washability curves were in good agreement with the washability curves predicted using the Mayer method for the same blending *** work resulted in the preparation of the optimum plant feed that can be achieved from the blending of different coal samples to produce the best plant yield at a given ash content.

关键词： Coal Dense medium separation Gravity concentration Mayer curve

Mineralogical and sink-float studies of Jajarm low-grade bauxite

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International Journal of Minerals,Metallurgy and Materials 2010年第3期17卷 251-256页

作者： Mohammad Zarbayani esmaeil jorjani Mirsaleh Mirmohammadi Mohammad Taghi Shadloo Mohammad Noaparast Science and Research Branch Islamic Azad University School of Mining engineering University of Tehran Jajarm Alumina Company

Jajarm＇s bauxite deposits are mainly diasporic, and they have a low mass ratio of Al2O3/SiO2. It is necessary to increase the run-of-mine mass ratio before feeding the material to the Bayer process. Chemical analysis indicated that the low-grade bauxite sample from Jajarm contained 43.9wt% Al2O3 and 13.35wt% SiO2, resulting in a mass ratio of 3.29. According to mineralogical studies, the presence of aluminosilicate minerals such as kaolinite, illite, and quartz was the main reason for the decrease of the mass ratio. Microscopic observations revealed that, with the size reduction from -1000＋710 to -38 μm, the liberation degree of diaspore increased from 10% to 60%, and that of aluminosilicates increased from 20% to 85%. Heavy liquids with the densities of 2.8, 3.0, 3.2, and 3.4 g/cm3 were used to evaluate the heavy media separation in three sizes, i.e., -3350＋710, -710＋212, and -212＋125 μm. Laboratory studies confirm that the density of 3.2 g/cm3 can produce the concentrates （in sunk fractions） with recoveries of 89.09%, 91.24%, and 84.68% with the Al2O3/SiO2 mass ratios of 5.03, 5.16, and 5.15 for the -3350＋710, -710＋212, and -212＋ 125 μ m sizes, respectively.

关键词： bauxite diaspore aluminosilicate mass ratio heavy media

Modeling the effects of ore properties on water recovery in the thickening process

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International Journal of Minerals,Metallurgy and Materials 2014年第9期21卷 851-861页

作者： Majid Unesi Mohammad Noaparast Seiyd Ziaedin Shafaei esmaeil jorjani Department of Mining engineering Tehran Science and Research branch of Islamic Azad University School of Mining engineering University of Tehran

A better understanding of solid-liquid separation would assist in improving the thickening performance and perhaps water recovery as well. The present work aimed to develop an empirical model to study the effects of ore properties on the thickening process based on pilot tests using a column. A hydro-cyclone was used to prepare the required samples for the experiments. The model significantly predicted the experimental underflow solid content using a regression equation at a given solid flux and bed level for different samples, indicating that ore properties are the effective parameters in the thickening process. This work confirned that the water recovery would be increased about 5% by separating the feed into two parts, overflow and underflow, and introducing two different thickeners into them separately. This is duo to the fact that thickeners are limited by permeability and compressibility in operating conditions.

关键词： mineral processing ores properties railings dewatedng modeling thickeners

Constrained bilinear control problem： Application to a cancer chemotherapy model

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International Journal of Biomathematics 2017年第4期10卷 189-209页

作者： e1 Hassan Zerrik Nihale e1 Boukhari MA CS Team Faculty of Sciences Moulay Ismail University Meknes Morocco

The aim of this paper is to investigate the optimal control problem for finite-dimensional bilinear systems and its application to a chemotherapy model. We characterize an opti- mal control that minimizes a quadratic cost functional in two cases of constrained admis- sible controls, then we give sufficient conditions for the uniqueness of such a control, and we derive useful algorithms for the computation of the optimal control. The established results are applied to a cancer chemotherapy bilinear model in order to simulate the opti- mal treatment protocol using two different approaches： one based on a limited instant toxicity, and the other on a limited cumulative toxicity along the therapy session.

关键词： Bilinear systems optimal control chemotherapy instant toxicity cumulativetoxicity.

experimental determination of interfacial energies for Ag_2Al solid solution in the CuAl_2-Ag_2Al system

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Chinese Physics B 2009年第9期18卷 3952-3959页

作者： Ocak Y Akbulut S Keslioglu K Marasl1 N ad1rl1 e Kaya H Department of Physics Faculty of Arts and SciencesErciyes University Department of Physics Institute of Science and TechnologyErciyes University Department of Physics Faculty of Arts and SciencesNigde University Department of Science education Education FacultyErciyes University

The equilibrated grain boundary groove shapes of solid solution Ag2Al in equilibrium with an AI-Cu-Ag liquid were observed from a quenched sample with a radial heat flow apparatus. The Gibbs Thomson coefficient, solid liquid interfacial energy and grain boundary energy of the solid solution Ag2Al have been determined from the observed grain boundary groove shapes. The thermal conductivity of the solid phase and the thermal conductivity ratio of the liquid phase to solid phase for Ag2Al-28.3 at the %CuAl2 alloy at the melting temperature have also been measured with a radial heat flow apparatus and Bridgman type growth apparatus, separately.

关键词： solid-liquid interfaces metals and alloys surface energy thermal conductivity

A CONJUGATe GRADIeNT MeTHOD FOR DISCReTe-TIMe OUTPUT FeeDBACK CONTROL DeSIGN

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Journal of Computational Mathematics 2012年第3期30卷 279-297页

作者： e1-Sayed M.e. Mostafa Department of Mathematics Faculty of Science Alexandria University Alexandria Egypt

In this paper, the discrete-time static output feedback control design problem is con- sidered. A nonlinear conjugate gradient method is analyzed and studied for solving an unconstrained matrix optimization problem that results from this optimal control prob- lem. In addition, through certain parametrization to the optimization problem an initial stabilizing static output feedback gain matrix is not required to start the conjugate gradi- ent method. Finally, the proposed algorithms are tested numerically through several test problems from the benchmark collection.

关键词： Output feedback control Nonlinear conjugate gradient methods Nonlinearprogramming.