Dynamic modeling of mineral bed mobility in centrifugal concentrators

2021 ◽  
pp. 114-119
Author(s):  
M.A. Perepelkin ◽  
V.I. Sklyanov
Keyword(s):  
Separation Factor ◽  
Water Pressure ◽  
Automation System ◽  
Effective Parameters ◽  
Gold Extraction ◽  
Mineral Particles ◽  
Laboratory Setup ◽  
Bed Mobility ◽  
Fluidization System ◽  
Optimum Water

The article discusses a method for determining the effective parameters of centrifugal concentrators with fluidization of a mineral bed with water through holes in the walls of a rotating cone. The device and the principle of operation of a laboratory setup for studying the constrained movement of mineral particles in a centrifugal field are described. Also, the optimization of the degree of loosening of the mineral bed in the centrifugal concentrator is considered. It was established experimentally that with existing water flow rates the condition of the mineral bed was close to the pressed state. Using the developed method of optimizing the ratio of water pressure in the fluidization system and the separation factor, the optimum water pressure and its flow rate were calculated in laboratory conditions. As a result, it was possible to raise the extraction during the first stage of gravity concentration by 2%. Therefore, it was determined that the degree of loosening depends on the correlation of the separation factor and the water pressure in the fluidization system. Based on the proposed approach, it is possible to develop an automation system to adjust the parameters of the centrifugal concentrators. Based on the results of calculating the balance of the concentration process in the gold extraction plant at the Kedrovskoe deposit, it was established that the application of the proposed methodology helped to improve the efficiency of the centrifugal free-flow concentrator.

Aspects of the behaviour of compacted clayey soils on drying and wetting paths

2002 ◽  
Vol 39 (6) ◽  
pp. 1341-1357 ◽  
Author(s):  
Jean-Marie Fleureau ◽  
Jean-Claude Verbrugge ◽  
Pedro J Huergo ◽  
António Gomes Correia ◽  
Siba Kheirbek-Saoud
Keyword(s):  
Water Content ◽  
Pore Water ◽  
Unsaturated Soils ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Dry Density ◽  
Clayey Soils ◽  
Maximum Dry Density ◽  
Optimum Water Content ◽  
Optimum Water

A relatively large number of drying and wetting tests have been performed on clayey soils compacted at the standard or modified Proctor optimum water content and maximum density and compared with tests on normally consolidated or overconsolidated soils. The results show that drying and wetting paths on compacted soils are fairly linear and reversible in the void ratio or water content versus negative pore-water pressure planes. On the wet side of the optimum, the wetting paths are independent of the compaction water content and can be approached by compaction tests with measurement of the negative pore-water pressure. Correlations have been established between the liquid limit of the soils and such properties as the optimum water content and negative pore-water pressure, the maximum dry density, and the swelling or drying index. Although based on a limited number of tests, these correlations provide a fairly good basis to model the drying–wetting paths when all the necessary data are not available.Key words: compaction, unsaturated soils, clays, drying, wetting, Proctor conditions.

EFFECTIVE PARAMETERS OF TAIL PROCESSING GOLD-BEARING ORE HYDROTRANSPORT FOR VERNINSKAYA PROCESSING FACTORY

2020 ◽  
Vol 23 (1) ◽  
Author(s):  
Victor Alexandrov ◽  
◽  
Arseny Kuzhelev ◽  
Anna Vatlina ◽  
◽  
...  
Keyword(s):  
Experimental Studies ◽  
Head Loss ◽  
Transport Systems ◽  
Hydraulic Transport ◽  
Effective Parameters ◽  
High Concentration ◽  
Rotational Viscometer ◽  
Laboratory Setup ◽  
Straight Lines ◽  
Gold Bearing

The paper shows that in order to increase the efficiency of hydraulic transport systems in mining the transportation of slurries with a high concentration of solids in the slurry flow. Experimental studies have shown that slurry tailings of gold-containing ore with mass concentration of more than 55% are viscoplastic fluids. Experiments on a rotational viscometer allowed us to establish the main rheological characteristics of the studied slurries. Experimental studies of hydraulic transport performed on a laboratory setup, confirmed the results obtained on a rotational viscometer. Curved mixture streams are inclined straight lines that cut off on the axis of the head the sections, which determine the initial hydraulic slope corresponding to the shear stress yield on the rheological curves. According to the results of the experiments, a method has been developed for calculating the hydraulic transport of highly concentrated slurries of tailings of gold-bearing ore. Head loss values increase with increasing concentration. A sharp increase in head loss occurs in the concentration range from 60 to 65% and above

scholarly journals Study on Energy Saving Control of Electrical Auto- mation System for Construction Equipment

1970 ◽  
Vol 1 (1) ◽  
Author(s):  
Huang Min Ma Lianhua
Keyword(s):  
Energy Saving ◽  
Heat Pump ◽  
Water Pressure ◽  
Construction Equipment ◽  
Automation System ◽  
Lighting System ◽  
Variable Air Volume ◽  
Air Volume ◽  
The Future ◽  
Energy Saving Control

To improve the existing problems of traditional construction equipment through electrical automation system, such as low water pressure on high floor, irrational lighting system and energy consumption of air conditioning system. Methods: The energy saving control of electrical automation system of construction equipment was studied in detail from four aspects: heat pump, variable air volume, enthalpy and lighting system. Results: The heat pump, variable air volume, enthalpy, lighting system energy saving control optimization, on the one hand to provide people comfortable and suitable for the surrounding environment, on the other hand to enhance the efficiency of building equipment control and resource utilization. Conclusion: The introduction of new technology in construction equipment is in line with China’s sustainable development concept. Energy saving and environmental protection is the future development direction of the construction market and needs further exploration in the future.

The growth of mica polytypes as studied by conventional and high-resolution TEM

1983 ◽  
Vol 41 ◽  
pp. 174-177
Author(s):  
A. Baronnet ◽  
M. Amouric
Keyword(s):  
Water Pressure ◽  
Point Of View ◽  
Temperature Fields ◽  
Natural Occurrence ◽  
Growth Mechanisms ◽  
Long Period ◽  
High Resolution Tem ◽  
Layer Stacking ◽  
Experimental Works ◽  
Potential Use

The origin of mica polytypes has long been a challenging problem for crystal- lographers, mineralogists and petrologists. From the petrological point of view, interest in this field arose from the potential use of layer stacking data to furnish further informations about equilibrium and/or kinetic conditions prevailing during the crystallization of the widespread mica-bearing rocks. From the compilation of previous experimental works dealing with the occurrence domains of the various mica "polymorphs" (1Mr, 1M, 2M1, 2M2 and 3T) within water-pressure vs temperature fields, it became clear that most of these modifications should be considered as metastable for a fixed mica species. Furthermore, the natural occurrence of long-period (or complex) polytypes could not be accounted for by phase considerations. This highlighted the need of a more detailed kinetic approach of the problem and, in particular, of the role growth mechanisms of basal faces could play in this crystallographic phenomenon.

The analysis of “Gels” in polymer films

1989 ◽  
Vol 47 ◽  
pp. 362-363
Author(s):  
G. M. Brown ◽  
D. F. Brown ◽  
J. H. Butler
Keyword(s):  
Molecular Weight ◽  
Film Industry ◽  
Local Stress ◽  
Melt Index ◽  
Polyethylene Films ◽  
Crosslinked Polymer ◽  
Polymeric Gels ◽  
Mineral Particles ◽  
Polymeric Species ◽  
Special Concern

The term “gel”, in the jargon of the plastics film industry, may refer to any inclusion that produces a visible artifact in a polymeric film. Although they can occur in any plastic product, gels are a principle concern in films where they detract from the cosmetic appearance of the product and may compromise its mechanical strength by acting as local stress concentrators. Many film gels are small spheres or ellipsoids less than one millimeter in diameter whereas other gels are fusiform-shaped and may reach several centimeters in length. The actual composition of gel inclusions may vary from miscellaneous inorganics (i.e. glass and mineral particles) and processing additives to heavily oxidized, charred or crosslinked polymer. The most commonly observed gels contain polymer differing from the bulk of the sample in its melt viscosity, density or molecular weight.Polymeric gels are a special concern in polyethylene films. Over the years and with the examination of a variety of these samples three predominant polymeric species have been observed: density gels which have different crystallinity than the film; melt-index gels in which the molecular weight is different than the film and crosslinked gels which are comprised of crosslinked polyethylene.

Long-term variations in individual particle types in the aerosol of Phoenix, Arizona, as determined using automated electron microprobe analysis and multivariate statistical techniques

1993 ◽  
Vol 51 ◽  
pp. 742-743
Author(s):  
Karen A. Katrinak ◽  
James R. Anderson ◽  
Peter R. Buseck
Keyword(s):  
Electron Microprobe ◽  
Fine Fraction ◽  
Coarse Fraction ◽  
Motor Vehicles ◽  
Multivariate Statistical Methods ◽  
Multivariate Statistical ◽  
X Ray ◽  
Mineral Particles ◽  
Anthropogenic Air Pollutants

Aerosol samples were collected in Phoenix, Arizona on eleven dates between July 1989 and April 1990. Elemental compositions were determined for approximately 1000 particles per sample using an electron microprobe with an energy-dispersive x-ray spectrometer. Fine-fraction samples (particle cut size of 1 to 2 μm) were analyzed for each date; coarse-fraction samples were also analyzed for four of the dates.The data were reduced using multivariate statistical methods. Cluster analysis was first used to define 35 particle types. 81% of all fine-fraction particles and 84% of the coarse-fraction particles were assigned to these types, which include mineral, metal-rich, sulfur-rich, and salt categories. "Zero-count" particles, consisting entirely of elements lighter than Na, constitute an additional category and dominate the fine fraction, reflecting the importance of anthropogenic air pollutants such as those emitted by motor vehicles. Si- and Ca-rich mineral particles dominate the coarse fraction and are also numerous in the fine fraction.

A brain-based adaptive automation system and situation awareness: The role of complacency potential

2003 ◽  
Author(s):  
Nathan R. Bailey ◽  
Mark W. Scerbo ◽  
Frederick G. Freeman ◽  
Peter J. Mikulka ◽  
Lorissa A. Scott
Keyword(s):  
Situation Awareness ◽  
Automation System ◽  
Adaptive Automation

Comparative study of the effective parameters on residual stress relaxation in welded aluminum plates under cyclic loading

2020 ◽  
Vol 21 (5) ◽  
pp. 505
Author(s):  
Yousef Ghaderi Dehkordi ◽  
Ali Pourkamali Anaraki ◽  
Amir Reza Shahani
Keyword(s):  
Residual Stress ◽  
Cyclic Loading ◽  
Stress Relaxation ◽  
Stress Amplitude ◽  
Cyclic Plasticity ◽  
Mean Stress ◽  
Effective Parameters ◽  
Perfect Plasticity ◽  
Residual Stress Relaxation ◽  
Aluminum Plates

The prediction of residual stress relaxation is essential to assess the safety of welded components. This paper aims to study the influence of various effective parameters on residual stress relaxation under cyclic loading. In this regard, a 3D finite element modeling is performed to determine the residual stress in welded aluminum plates. The accuracy of this analysis is verified through experiment. To study the plasticity effect on stress relaxation, two plasticity models are implemented: perfect plasticity and combined isotropic-kinematic hardening. Hence, cyclic plasticity characterization of the material is specified by low cycle fatigue tests. It is found that the perfect plasticity leads to greater stress relaxation. In order to propose an accurate model to compute the residual stress relaxation, the Taguchi L18 array with four 3-level factors and one 6-level is employed. Using statistical analysis, the order of factors based on their effect on stress relaxation is determined as mean stress, stress amplitude, initial residual stress, and number of cycles. In addition, the stress relaxation increases with an increase in mean stress and stress amplitude.

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