A process mineralogy approach to study the efficiency of milling of molybdenite circuit processing

AbstractThis study is conducted with the aim of investigating the efficiency of open and closed-circuit molybdenite ore comminution processes (primary and secondary mill, respectively), through mineralogical study of mills feed and product. For this purpose, particle size distribution, minerals distribution, degree of liberation and interlocking of minerals in mills feed and product were studied. According to the results, chalcopyrite, molybdenite, pyrite and covellite constitute the major part of the mineral composition of open-circuit mill feed. Minerals at the mill product, in the order of abundance include liberated molybdenite particles, liberated chalcopyrite and interlocked chalcopyrite with pyrite, liberated and interlocked pyrite particles, and associated silicate gangues. The d50 values of the feed and product particles of the open-circuit mill are equal to 13.80 and 13.40 microns, respectively. Degree of liberation of molybdenite for the feed and product of this mill is almost the same and is equal to 98.0%. Closed-circuit mill feed includes, in order of is abundance, liberated molybdenite particles in the form of blades and irregular polygonal shapes, liberated and interlocked chalcopyrite, and liberated and interlocked pyrite particles with gangue minerals. Molybdenite particles in the mill product are almost completely liberated, and the degree of liberation values of chalcopyrite and pyrite are 84.40% and 91.40%, respectively. According to particles size distribution of the feed (d50 equal to 25.03 microns) and the product (d50 equal to 24.24 microns) of closed-circuit mill, it can be stated that comminution is not well-operated in closed-circuit mill due to the low solid percentage of closed-circuit mill feed and the inefficiency of hydrocyclone. Examination of Mo, Cu, and Fe grade variations for 10 days in both off and on modes of mill shows that closed-circuit mill does not have an impact on comminution process. It can even be concluded that the mill has a destructive effect the flotation process by producing slimes.

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Air flow quality analysis of an open-circuit boundary layer wind tunnel and comparison with a closed-circuit wind tunnel

Physics of Fluids ◽

10.1063/5.0031613 ◽

2020 ◽

Vol 32 (12) ◽

pp. 125120

Author(s):

María Jiménez-Portaz ◽

Luca Chiapponi ◽

María Clavero ◽

Miguel A. Losada

Keyword(s):

Boundary Layer ◽

Wind Tunnel ◽

Air Flow ◽

Open Circuit ◽

Closed Circuit ◽

Quality Analysis ◽

Flow Quality

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A Novel Turbulent Aggregation Device for Flue Gas

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.955-959.2425 ◽

2014 ◽

Vol 955-959 ◽

pp. 2425-2429 ◽

Cited By ~ 2

Author(s):

Yun Fei Li ◽

Jian Guo Yang ◽

Yan Yan Wang ◽

Xiao Guo Wang

Keyword(s):

Size Distribution ◽

Flue Gas ◽

Large Scale ◽

Balance Model ◽

Small Scale ◽

Multiphase Model ◽

Specific Performance ◽

Particles Size Distribution ◽

Scale Turbulence ◽

Eulerian Multiphase Model

The purpose of this study is to construct a turbulent aggregation device which has specific performance for fine particle aggregation in flue gas. The device consists of two cylindrical pipes and an array of vanes. The pipes extending fully and normal to the gas stream induce large scale turbulence in the form of vortices, while the vanes downstream a certain distance from the pipes induce small one. The process of turbulent aggregation was numerically simulated by coupling the Eulerian multiphase model and population balance model together with a proposed aggregation kernel function taking the size and inertia of particles into account, and based on data of particles’ size distribution measured from the flue of one power plant. The results show that the large scale turbulence generated by pipes favours the aggregation of smaller particles (smaller than 1μm) notably, while the small scale turbulence benefits the aggregation of bigger particles (larger than 1μm) notably and enhances the uniformity of particle size distribution among different particle groups.

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EVALUATION OF THE EFFECTIVENESS OF A CLOSED CIRCUIT IN COMPARISON WITH AN OPEN CIRCUIT OF CARDIOPULMONARY BYPASS

BULLETIN OF SURGERY IN KAZAKHSTAN ◽

10.35805/bsk2021iii044 ◽

2021 ◽

pp. 44-47

Author(s):

Berik Tuishiev ◽

Gulzhan Bayzhan ◽

Sabina Samitova

Keyword(s):

Cardiopulmonary Bypass ◽

Aortic Valve ◽

Postoperative Period ◽

Open Circuit ◽

Closed Circuit ◽

Control Group ◽

Study Group ◽

Valve Insufficiency ◽

Group 5 ◽

Group 2

Objective is to evaluate the effectiveness of closed-loop surgeries with the planned duration of cardiopulmonary bypass more than 2 hours in the immediate postoperative period. Materials and methods. A study was carried out in the clinic over 10 patients (average age 47-56 years) with Diagnoses: Ascending aortic aneurysm, FC 3 aortic valve insufficiency, who underwent surgery for ascending aorta replacement, aortic valve replacement with coronary artery reimplantation. The patients were divided into 2 groups, the 1st group (5 patients) is the control group using an open cardiopulmonary bypass circuit, the 2nd group (5 patients) is the patients using a closed cardiopulmonary bypass circuit. The total time of cardiopulmonary bypass in both groups was 125-187 minutes. Results. In the 2nd study group, drainage blood loss significantly decreased, on average 60-100 ml compared to the control group, where the average drainage loss was 600-1500 ml. The need for blood transfusion was 5.1% in the 2nd group, compared with 43.4% in the control group. In the study group 2, the number of platelets in the postoperative period in patients was higher than in the control group. Conclusion. This study shows that a closed circuit, compared to an open one, allows complex heart surgeries with a planned duration of extracorporeal circulation of more than 2-3 hours.

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Application Research of GMRES Algorithm in dynamic light scattering Particles Size Distribution Inversion

Physics Procedia ◽

10.1016/j.phpro.2012.02.306 ◽

2012 ◽

Vol 24 ◽

pp. 2089-2093

Author(s):

Dou Zhenhai ◽

Sun Lianyun

Keyword(s):

Light Scattering ◽

Dynamic Light Scattering ◽

Size Distribution ◽

Application Research ◽

Particles Size Distribution ◽

Gmres Algorithm

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Removal of clay and blue-green algae particles through zeta potential and particle size distribution in the dissolved air flotation process

Water Science & Technology Water Supply ◽

10.2166/ws.2006.011 ◽

2006 ◽

Vol 6 (1) ◽

pp. 95-103 ◽

Cited By ~ 5

Author(s):

D.H. Kwak ◽

S.J. Kim ◽

H.J. Jung ◽

C.H. Won ◽

S.B. Kwon ◽

...

Keyword(s):

Particle Size ◽

Zeta Potential ◽

Particle Size Distribution ◽

Size Distribution ◽

Green Algae ◽

Dissolved Air Flotation ◽

Flotation Process ◽

Clay Particles ◽

Blue Green Algae ◽

Dissolved Air

The raw water characteristics of a water treatment plant in Korea are mainly dependent on two major factors: the clay particles attributed to rainfall and blue-green algae in reservoirs. In this work, zeta potential and particle size distributions of clay and algae particles, which are the important parameters affecting their removal efficiency, were measured to investigate the behavior and removal characteristics of particles under various conditions. The results showed that the zeta potential of blue-green algae was more sensitive to treatment conditions than clay, and it fluctuated highly with coagulant dosage, suggesting that the control of zeta potential is important for effective removal of algae particles. On the other hand, the range of particle size distribution that remained from the preliminary sedimentation tank was generally smaller than for flotation. However, the zeta potential of the remaining particles was either close to the isoelectric point or positive, and the particles were not so hard to remove for that reason. In the final analysis, for simultaneous removal of clay and algae particles, a sufficient zeta potential difference must be formed not only for algae particles but also for small clay particles from the sedimentation tank in the dissolved air flotation process.

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SERS of a-C Thin Film on Ag, Au, Ag0.52-Au0.48 Alloy Nanoparticle Arrays with Normal Particles Size Distribution Formed by Vacuum Thermal Evaporation

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.386.250 ◽

2018 ◽

Vol 386 ◽

pp. 250-255 ◽

Cited By ~ 1

Author(s):

Sergey Dubkov ◽

Alexey Trifonov ◽

Yuri Shaman ◽

Evgeny Kitsyuk ◽

Andrey Savitskiy ◽

...

Keyword(s):

Thin Film ◽

Particle Size ◽

Raman Scattering ◽

Size Distribution ◽

Thermal Evaporation ◽

Experimental Studies ◽

Alloy Nanoparticles ◽

Nanoparticle Arrays ◽

Vacuum Thermal Evaporation ◽

Particles Size Distribution

This paper presents the results of experimental studies of arrays of Ag0.52Au0.48 alloy nanoparticles. Arrays were formed by vacuum-thermal evaporation on an unheated substrate and subsequent low-temperature vacuum annealing. The TEM images of the obtained nanoparticle arrays and corresponding histograms of particle size distribution are shown. The transmission spectra of these arrays showing the displacement of the plasma frequency as a function of the mean particle size are obtained. Spectra of Raman scattering from a thin film of amorphous carbon in presence of AgAu particles are obtained, and a comparative analysis of Raman scattering amplification factors for pure Ag, pure Au and Ag0.52Au0.48 alloy nanoparticles is presented.

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Identification of loess by a particles size distribution using the Coulter Counter TA II

International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts ◽

10.1016/0148-9062(85)93051-7 ◽

1985 ◽

Vol 22 (4) ◽

pp. 119

Keyword(s):

Size Distribution ◽

Coulter Counter ◽

Particles Size Distribution

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Processing of the lead-zinc ore from the Pavlovsk deposit

Tsvetnye Metally ◽

10.17580/tsm.2020.12.05 ◽

2020 ◽

pp. 33-39

Author(s):

S. S. Plyasovitsa ◽

◽

O. A. Kravtsova ◽

N. V. Ivanova ◽

I. Yu. Semenov ◽

...

Keyword(s):

Metal Concentration ◽

High Quality ◽

Valuable Component ◽

Flotation Process ◽

X Ray ◽

Lead And Zinc ◽

Mineralogical Study ◽

Lead Zinc ◽

Zinc Concentrate

The authors carried out a mineralogical study and substantiated a concentration process developed for the lead-zinc ores of the Pavlovsk deposit. The concentration of the valuable component in each type of concentrate is determined by the amount of pyrite contained in the ore. It was established that the main loss of lead with flotation tailings is associated with oxidized phases, which are mainly found in fine material. Lead sulphides account for 30% of the entire waste tailings. Using the results of the mineralogical study, a flotation process was developed that involves a staged separation of commercial lead and zinc concentrates, as well as waste tailings. The obtained zinc concentrate has a consistently high quality of 57–58% with an 85–90% recovery. The metal concentration in the lead concentrate 1 is 45%, with the recovery being 43%. On the basis of the experimental results, the authors propose to use an X-ray radiometric separation method for coarse ore, which will help reduce the amount of incoming ore by 30% while minimizing the loss of lead and zinc.

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