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Validation and Implementation of Cold Purification Cake Leaching in Ammoniacal Carbonate Solutions at Hindustan Zinc Hydro Refineries
Sundar Saran Sombhatla,
Ashish Kumar,
Akhilesh Shukla,
Kiran Kumar,
Sheeba Mashruwala
Issue:
Volume 6, Issue 2, March 2018
Pages:
26-34
Received:
15 December 2017
Accepted:
27 December 2017
Published:
19 January 2018
Abstract: As a part of regular purification process for zinc leachate, cold purification cake is being generated at Hindustan Zinc refineries. Since the cake is being accumulated as an inventory, a treatment process has been designed to recover the copper in house and utilize it as an activator in zinc flotation circuit. It majorly contains copper (30-40%) along with zinc (10-20%) and cadmium (2%). With confirmation to the above statement, photomicrographs of purification cake also confirmed the major presence of copper in metallic or oxidized form. In present work ammoniacal carbonate leaching of purification cake followed by solvent extraction using diketone based solvent has been studied under the influence of various parameters viz., temperature, agitation, pulp density, ammonia, CO2 dosages, solvent concentration, and impact of w/s zinc on leaching and solvent extraction. Leaching kinetics determined based on shrinking core model. Chemical reaction at unreacted core was found to be the rate controlling step. The estimated activation energy was found to be 24 KJ/mol. Leached copper has been extracted by solvent extraction with a β diketone based solvent and is stripped with sulfuric acid as concentrated copper sulfate solution. The above established R&D findings are successfully implemented in the Commercial plant with a treatment capacity of two tons of cold purification cake per batch.
Abstract: As a part of regular purification process for zinc leachate, cold purification cake is being generated at Hindustan Zinc refineries. Since the cake is being accumulated as an inventory, a treatment process has been designed to recover the copper in house and utilize it as an activator in zinc flotation circuit. It majorly contains copper (30-40%) a...
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Study of Monte Carlo Simulator for Estimation of Anti-Scatter Grid Physical Characteristics on IEC 60627:2013-Based
Woo-Hyun Chung,
Sang-Hyun Lee
Issue:
Volume 6, Issue 2, March 2018
Pages:
35-42
Received:
27 December 2017
Accepted:
9 January 2018
Published:
19 January 2018
Abstract: The anti-scatter grid (grid) is a major component of X-ray imaging devices, improving the quality of the image by removing X-rays scattered while passing through the subject. However, problems such as image distortions or increasing the dose of a patient unnecessarily may result if the grid is not suitable for a specific digital x-ray receptor (detector.) Selecting a suitable grid can take significant work and testing due to the wide range of specifications and physical characteristic of both grid and digital imaging x-ray detectors. In order to reduce the time cost and to improve the accuracy of selecting a suitable grid, this study implemented a Monte Carlo simulation for estimating the physical characteristics of the grid and verified the accuracy of the result by comparing with the physical characteristics of the actual grid. For the verification, this study compared the estimated physical characteristics with the measured physical characteristics for ten (10) grids with different specifications. The physical characteristics were measured at RQR (Radiation Qualities in Radiation Beams emerging from the X-ray Source Assembly) 4/6/8/9 of the Radiation conditions and analyzed Transmission of Primary radiation (Tp), Transmission of Total radiation (Tt) and Transmission of Scattered radiation (Ts) of the physical characteristics of the grid. As a result of the analysis, less than 1% average deviation between simulation and physical measurement was observed with all ten (10) grids. The changes of the physical characteristics as the specifications (line density and ratio) of the grid changed were also evaluated, and found to have a Pearson’s correlation coefficient of 0.998 between simulation and measurements. From the above results, the proposed program in this paper is judged reasonable as a grid physical characteristics prediction program.
Abstract: The anti-scatter grid (grid) is a major component of X-ray imaging devices, improving the quality of the image by removing X-rays scattered while passing through the subject. However, problems such as image distortions or increasing the dose of a patient unnecessarily may result if the grid is not suitable for a specific digital x-ray receptor (det...
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Physical Properties of Copper Oxide Thin Films Prepared by Sol–Gel Spin–Coating Method
Mehdi Dhaouadi,
Mohamed Jlassi,
Imen Sta,
Islem Ben Miled,
George Mousdis,
Michael Kompitsas,
Wissem Dimassi
Issue:
Volume 6, Issue 2, March 2018
Pages:
43-50
Received:
26 November 2017
Accepted:
5 December 2017
Published:
29 January 2018
Abstract: In this study, copper oxide thin films prepared by the sol–gel method, have been deposed onto glass substrates by the spin coating technique. Our target was to study their properties and improve them for photovoltaic use. These properties were optimized by varying the temperature annealing and the molar concentration of the precursor solutions. The effects of the annealing temperature on the structural and optical properties of the thin films are studied. It was found that the film treated at 550°C shows a higher absorbance. Then by using this optimized temperature, CuO thin films of various molar concentrations, were deposited at the same experimental conditions. The structural analysis by X- ray diffraction (XRD) shows that all the samples are polycrystalline with monoclinic crystal structure. Raman scattering measurements of all thin films confirms the structure of CuO. The optical properties of the films were characterized by UV–Visible–NIR spectrophotometry, which shows that the films show high absorbance in the visible region. Their optical band gap decreases from 3.68 to 2.44 eV when the molar concentration of precursor solutions increases from 0.1 to 0.5 M. The electrical measurements show that the resistivity of the films varies slightly from 84 Ω cm to 124 Ω cm as the molar concentration increases.
Abstract: In this study, copper oxide thin films prepared by the sol–gel method, have been deposed onto glass substrates by the spin coating technique. Our target was to study their properties and improve them for photovoltaic use. These properties were optimized by varying the temperature annealing and the molar concentration of the precursor solutions. The...
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Methods for Assessing the Seismic Resistance of Subterranean Hydro Structures Under the Influence of Seismic Waves
Safarov Ismail Ibrahimovich,
Boltayev Zafar Ixtiyorovich
Issue:
Volume 6, Issue 2, March 2018
Pages:
51-62
Received:
20 December 2017
Accepted:
5 February 2018
Published:
23 February 2018
Abstract: The paper considers the seismic resistance of subterranean hydro constructions of various shapes under the influence of seismic waves. The review is dedicated to the abovementioned issues. Recommendations on increasing seismic resistance of underground hydraulic structures under the action of seismic waves are suggested.
