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International Journal of Minerals,Metallurgy and Materials 2010年第5期17卷 526-534页

作者： Saeed Chehreh Chelgani Behzad Shahbazi bahram rezai Surface Science Western Research Park University of Western Ontario Mining Engineering Department Science and Research Branch Islamic Azad University Amirkabir University of Technology

An artificial neural network and regression procedures were used to predict the recovery and collision probability of quartz flotation concentrate in different operational conditions. Flotation parameters, such as dimensionless numbers （Froude, Reynolds, and Weber）, particle size, air flow rate, bubble diameter, and bubble rise velocity, were used as inputs to both methods. The linear regression method shows that the relationships between flotation parameters and the recovery and collision probability of flotation can achieve correlation coefficients （R2） of 0.54 and 0.87, respectively. A feed-forward artificial neural network with 3-3-3-2 arrangement is able to simultaneously estimate the recovery and collision probability as the outputs. In testing stages, the quite satisfactory correlation coefficient of 0.98 was achieved for both outputs. It shows that the proposed neural network models can be used to determine the most advantageous operational conditions for the expected recovery and collision probability in the froth flotation process.

关键词： flotation recovery collision probability neural networks

Dynamic simulation of pilot thickener operation using phenomenological model with results validation for continuous and discontinuous tests

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Journal of Central South University 2017年第5期24卷 1207-1216页

作者： Rahimi Mehdi Unesi Majid rezai bahram Abdollahzadeh Ali Department of Mining and Metallurgical Engineering Amirkabir University of Technology Young Researchers and Elites Club Science and Research Branch Islamic Azad University Department of Mining Engineering University of Kashan

The phenomenological theory of sedimentation-thickening processes predicts the settling behavior of a flocculated suspension in dependence of two functions, the batch flux density function and the effective solid stress. These functions were determined using batch settling tests. The governing equations for sedimentation were then solved numerically for these functions and the predictions were compared to the experimental results from pilot scale thickener tests. Firstly, the continuous tests were performed in the plexiglass pilot thickener at different feed flow rates and discharge rates and the solid volume fraction of discharge, the bed height and the time were recorded for each condition. These tests were also simulated and it was observed that there is a good agreement between the results of continuous tests and the results of dynamic simulation. Secondly, the discontinuous tests were performed in the plexiglass pilot thickener at different feed flow rates with a discharge rate of zero. The bed formation rate was determined for each condition. These tests were also simulated and it was observed that there is a good agreement between the results of discontinuous tests and the results of simulation.

关键词： dynamic simulation dewatering thickener behavior pilot thickener validation

Bonded-particle model calibration using response surface methodology

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Particuology 2017年第3期15卷 141-152页

作者： Sajjad Chehreghani Mohammad Noaparast bahram rezai Sied Ziaedin Shafaei School of Mining University College of Engineering University of Tehran. 14395-515. Tehran Iran Department of Mining and Metallurgy Engineering. Amir Kabir University of Technology Tehran Iran

The bonded-particle model （BPM） is commonly used in numerical analysis of the mechanical behavior of rock samples. Constructing a BPM model requires specification of a number of microstructural parame- ters, including the parallel-bond tensile strength, parallel-bond cohesion strength, parallel-bond effective modulus, parallel-bond friction angle, and parallel-bond stiffness ratio. These parameters cannot be eas- ily measured in the laboratory or directly related to either measurable or physical material parameters. Hence, a calibration process is required to choose the values to be used in simulations of physical systems. In this study, response surface methodology along with the central composite design approach is used to calibrate BPMs. The sensitivities of the microparameters related to the uniaxial compressive strength （UCS） and elasticity modulus （i.e., the macroscopic responses of the models） are thoroughly scrutinized. Numerical simulations are performed to carefully assess the performance of the model. It is found that the elasticity modulus is highly correlated with the parallel-bond effective modulus. In addition, the parallel- bond tensile and cohesion strengths are the two most significant microparameters with a considerable effect on the UCS. The predicted values determined by the proposed approach are in good agreement with the observed values, which verifies the applicability of the proposed method.

关键词： Bonded-particle modelCalibrationResponse surface methodologyUniaxial compressive strength

Influence of the roughness and shape of quartz particles on their flotation kinetics

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International Journal of Minerals,Metallurgy and Materials 2012年第4期19卷 284-289页

作者： Mehdi Rahimi Fahimeh Dehghani bahram rezai Mohammad Reza Aslani Department of Mining and Metallurgical Engineering Amirkabir University of Technology Department of Mining Engineering Science and Research Branch Islamic Azad University

Surface roughness and shape play an important role on the behavior of particles in various processes such as flotation. In this re- search, the influence of different grinding methods on the surface roughness and shape characteristics of quartz particles as well as the effect of these parameters on the flotation of the particles was investigated. The surface roughness of the particles was determined by measuring their specific surface area via the gas adsorption method. The shape characteristics of the particles were measured and calculated by images obtained by scanning electron microscopy via an image analysis system. The flotation kinetics was determined using a laboratory flotation cell. The results showed that the particles of rod mill products have higher roughness and elongation ratio and lower roundness than the parti- cles of ball mill products. The flotation kinetics constant of the particles increased with their surface roughness increasing. Particles with higher elongation and lower roundness indicated higher floatability. In addition, the influence of the surface roughness on the flotation kinet- ics was greater than that of shape parameters.

关键词： flotation kinetics quartz shape parameters surface roughness

Effect of microwave pretreatment on grinding and flotation kinetics of copper complex ore

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International Journal of Minerals,Metallurgy and Materials 2021年第12期28卷 1887-1897页

作者： Hamed Gholami bahram rezai Ahmad Hassanzadeh Akbar Mehdilo Mohammadreza Yarahmadi Department of Mining and Metallurgical Engineering Amirkabir University of TechnologyTehran 158754413Iran Department of Geoscience and Petroleum Faculty of Engineering ScienceNorwegian University of Science and TechnologyNO-7491TrondheimNorway Faculty of Engineering University of Mohaghegh ArdabiliArdabil ***Iran Research and Development Division Sarcheshmeh Copper MineNational Iranian Copper Industries CompanyRafsanjanIran

The present study initially investigates the kinetics of microwave-assisted grinding and flotation in a porphyry copper *** tests were conducted on untreated and microwave-irradiated samples by varying the exposure time from 15 to 150 *** microscopy,energy-dispersive X-ray spectroscopy,and scanning electron microscopy were conducted to determine the mineral liberation and particle surface properties,and to perform mineralogical *** showed that the ore breakage rate constant monotonically increased by increasing the exposure time,particularly for the coarsest fraction size(400μm)due to the creation of thermal stress fractures alongside grain *** irradiation time(>60 s)led to the creation of oxidized and porous surfaces along with a dramatic change in particle morphologies that result in a substantial reduction of chalcopyrite and pyrite flotation rate constants and ultimate *** concluded that MW-pretreated copper ore was ground faster than the untreated variety,but the two types have slightly similar floatabilities.

关键词： grinding microwave copper

Dynamic simulation of the effect of time-dependent variation of pH on response variable of the tailing thickener of coal washing plant

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International Journal of Coal Science & Technology 2019年第1期6卷 127-137页

作者： Mehdi Rahimi Ali Akbar Abdollahzadeh bahram rezai Department of Mining and Metallurgical Engineering Amirkabir University of Technology TehranIran Department of Mining Engineering University of KashanKashanIran

Dynamic simulation approach can be used for understanding the nonlinear behavior in mineral processing circuits. In this study, the gel point, the main parameters of batch flux density function and the main parameters of effective solid stress were determined at different conditions (pH, flocculant dosage and particle size). Therefore, the main parameters of phenome no logical model of sedimentation and thickening were determined as a functio n of particle size, pH and flocculant dosages using the result of experimental tests and Curve expert professional software. Then, the dynamic simulation was carried out for the industrial thickener of coal washing plant and the time-dependent variation of response variables was investigated by time-dependent variation of pH of input feed to thickener using the obtained equations. It was observed that it is possible to predict the thickener behavior as a function of time for time dependent variation of pH of input feed to the thickener of coal washing plant using obtained equations that it was not possible using phenomenological model of thickener alone.

关键词： Dynamic simulation Dewatering Ideal continuous thickener Thickener behavior Time-dependent variation of pH

Numerical simulation of high voltage electric pulse comminution of phosphate ore

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International Journal of Mining Science and Technology 2015年第3期25卷 473-478页

作者： Razavian Seyed Mohammad rezai bahram Irannajad Mehdi Ravanji Mohammad Hasan Department of Mining and Metallurgical Engineering Amirkabir University of Technology Department of Electrical Engineering Sharif University of Technology

Numerical simulation of the electrical field distribution helps in-depth understanding of the mechanisms behind the responses and the benefits of the high voltage pulse comminution. The COMSOL Multiphysics package was used to numerically simulate the effect of ore compositions in this study. Regarding phosphate ore particles shape and composition, the effects of mineral composition, particle size, particle shape and electrodes distance were investigated on the electrical field intensity and distribution. The results show that the induced electrical field is significantly dependent on the electrical properties of minerals,the feed particle size and the location of conductive minerals in ores. The angle of material contact surface with the discharge electrode is also an important factor in the intensity of electrical field. Moreover,it is found that the specific liberation effect at the disintegration of phosphate ore by electrical pulses is due to the locality of the electrical field at the interface of mineral components of the phosphate ore aggregates with different permittivities. However, the intensity of the electrical field increases with sharpening the contact angle. Besides, the electrical discharge in the samples is converted to the electrohydraulic discharge across the surrounding water by changing the distance between the discharge electrode and sample surface.

关键词： Numerical simulation High voltage electric pulse Electrical comminution Phosphate ore

Semi-autogenous mill power prediction by a hybrid neural genetic algorithm

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Journal of Central South University 2018年第1期25卷 151-158页

作者： Hoseinian Fatemeh Sadat Abdollahzadeh Aliakbar rezai bahram Department of Mining and Metallurgical Engineering Amirkabir University of Technology Department of Mining Engineering University of Kashan

There are few methods of semi-autogenous(SAG)mill power prediction in the full-scale without using long *** this work,the effects of different operating parameters such as feed moisture,mass flowrate,mill load cell mass,SAG mill solid percentage,inlet and outlet water to the SAG mill and work index are studied.A total number of185full-scale SAG mill works are utilized to develop the artificial neural network(ANN)and the hybrid of ANN and genetic algorithm(GANN)models with relations of input and output data in the *** results show that the GANN model is more efficient than the ANN model in predicting SAG mill *** sensitivity analysis was also performed to determine the most effective input parameters on SAG mill *** sensitivity analysis of the GANN model shows that the work index,inlet water to the SAG mill,mill load cell weight,SAG mill solid percentage,mass flowrate and feed moisture have a direct relationship with mill power,while outlet water to the SAG mill has an inverse relationship with mill *** results show that the GANN model could be useful to evaluate a good output to changes in input operation parameters.

关键词： semi-autogenous mill mill power prediction sensitivity analysis artificial neural network genetic algorithm

New pretreatment method for high-tension electrical separation of zircon from quartz

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Transactions of Nonferrous Metals Society of China 2019年第8期29卷 1737-1743页

作者： Sivash NOURI Fatemeh Sadat HOSEINIAN bahram rezai Kamal SABERYAN Department of Mining and Metallurgical Engineering Amirkabir University of Technology Tehran 158754413 Iran Materials and Nuclear Fuel Research School Nuclear Science and Technology Research Institute Tehran 113653486 Iran

Electrostatic separation is one of the mineral processing methods based on mineral *** method has some significant problems such as being sensitive to humidity,high middling product,and impurity of non-conductive *** this study,a new pretreatment method was proposed for the separation of zircon from quartz before electrostatic separation to solve these *** this regard,two stages of pretreatment were applied which involved using collector of sodium dodecyl sulfate(SDS)for adjusting wettability of the zircon surface and spraying electrolyte aqueous solution to increase conductivity of the quartz *** effects of important parameters including pH,collector concentration,conditioning time,and concentration and type of electrolyte on the process efficiency were *** results showed that the optimal conditions of high-tension electrical separation were pH of 4,SDS concentration of 1×10-4 mol/L,conditioning time of 4 min and NaCl as an electrolyte with concentration of 4.27 mol/*** efficiency of 95.12% was achieved in optimum *** pretreatment method can be successfully used before high-tension electrical separation to separate the conductive or non-conductive minerals with various compositions.

关键词： zircon quartz collector electrolyte aqueous solution conductivity high-tension electrical separation surface treatment

Investigate of Effective Factors on Extraction of Silver from Tailings of Lead Flotation Plant Using Thiourea Leaching

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World Journal of Engineering and Technology 2016年第2期4卷 305-312页

作者： Bandehzadeh Masoud Aryanimehr Amir rezai bahram Department of Mining Engineering Science and Research Branch Islamic Azad University Tehran Iran Department of Mining Engineering Amirkabir University of Technology Tehran Iran

In current paper, the effect of different factors on extraction of silver from tailings of lead flotation plant using thiourea leaching was studied. According to the mineralogical studies and chemical analysis taken from the tailings dam, the representative sample taken from there contained 30 ppm Ag and the minerals such as calcite, dolomite, barite, microcline, galena etc. In this research, the effects of iron(III) sulfate concentration, thiourea concentration, size and temperature onextraction of silver from Ravanj flotation plant tailings were analyzed using statistics design of experiment and DX7 software;and it was determined that iron(III) sulfate concentration and temperature were the most effective factors on the extraction of silver. The results showed that the best recovery obtained in particle size of 75 microns, 1 kg/m3 thiourea concentration and 1 kg/m3 iron(III) sulfate concentration in the temperature of 60℃ for 2 hours.

关键词： Thiourea (TU) Design Experimental (DX7) Formamidine Disulfide (FDS)