scholarly journals Recovery of Copper, Nickel and Zinc from Sulfate Solutions by Solvent Extraction Using LIX 984N

2011 ◽  
Vol 8 (s1) ◽  
pp. S434-S438 ◽  
Author(s):  
Vaishnavi Sridhar ◽  
J. K. Verma
Keyword(s):  
Flow Sheet ◽  
Two Stage ◽  
Copper Nickel ◽  
Sulfate Solutions ◽  
Quantitative Extraction ◽  
Valuable Metals ◽  
Maximum Extraction ◽  
The Individual ◽  
Counter Current ◽  
Extraction Isotherms

Recovery of valuable metals such as copper, nickel and zinc from synthetic sulfate solutions using LIX 984N as the extractant dissolved in kerosene was investigated. The metals get extracted at different equilibrium pH of the aqueous phase and thus the pH of the aqueous solutions forms the basis of their separation. Copper was extracted at an equilibrium pH of 3.5, while nickel and zinc get extracted at an equilibrium pH of 7.3 and 8.8 respectively. The extraction isotherms of copper, nickel and zinc were obtained by contacting the respective metal solutions and 0.05 M LIX 984N at different A:O phase ratio at their respective equilibrium pH of maximum extraction. A two-stage counter- current extraction simulation was done to achieve quantitative extraction of the metals. Furthermore, a two-stage counter- current stripping simulation yielded quantitative recovery of the individual metals, from their loaded organic phases. On the basis of the results, a flow sheet of the process has been developed.

DOES TRUST PROMOTE ENTREPRENEURSHIP IN A DEVELOPING COUNTRY?

2018 ◽  
Vol 63 (05) ◽  
pp. 1385-1403 ◽  
Author(s):  
KITAE SOHN ◽  
ILLOONG KWON
Keyword(s):  
Developing Countries ◽  
Property Rights ◽  
Least Squares ◽  
Developing Country ◽  
Ordinary Least Squares ◽  
Community Level ◽  
Two Stage ◽  
The Us ◽  
The Difference ◽  
The Individual

Trust was found to promote entrepreneurship in the US. We investigated whether this was true in a developing country, Indonesia. We failed to replicate this; this failure was true whether trust was estimated at the individual or community level or whether ordinary least squares (OLS) or two stage least squares (2SLS) was employed. We reconciled the difference between our results and those for the US by arguing that the weak enforcement of property rights in developing countries and the consequent hold-up problem make it more efficient for entrepreneurs to produce generic goods than relationship-specific goods—producing generic goods does not depend on trust.

Distillation studies in a two-stage counter-current rotating packed bed

2013 ◽  
Vol 102 ◽  
pp. 62-66 ◽  
Author(s):  
Guang-Wen Chu ◽  
Xin Gao ◽  
Yong Luo ◽  
Hai-Kui Zou ◽  
Lei Shao ◽  
...  
Keyword(s):  
Packed Bed ◽  
Two Stage ◽  
Rotating Packed Bed ◽  
Counter Current

Valuable Metals Recovery from Tailings of Patched Copper—Nickel Ores

1995 ◽  
Vol 15 (1-4) ◽  
pp. 261-261
Author(s):  
E. K. YAKUBAILIK ◽  
V. V. RIBAS ◽  
A. G. ZVEGINZEV ◽  
V. T. DJACHENKO ◽  
L. S. STEPANENKO ◽  
...  
Keyword(s):  
Copper Nickel ◽  
Metals Recovery ◽  
Valuable Metals ◽  
Nickel Ores

Development of copper-on-alumina catalytic materials for the cleanup of flue gas and the disposal of diluted ammonium sulfate solutions

1995 ◽  
Vol 10 (3) ◽  
pp. 553-561 ◽  
Author(s):  
G. Centi ◽  
B.K. Hodnett ◽  
P. Jaeger ◽  
C. Macken ◽  
M. Marella ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Ammonium Sulfate ◽  
Flue Gas ◽  
Industrial Development ◽  
Power Plants ◽  
Flow Sheet ◽  
Catalytic Materials ◽  
Sulfate Solutions ◽  
The Stability ◽  
The Relationship

Some aspects of the industrial development of copper-on-alumina catalytic materials for the combined removal of SO2 (DeSOx and NOx (DeNOx) from flue gas of power plants are discussed. Applications of these catalytic materials for the recovery of sulfuric acid from diluted aqueous solutions of ammonium sulfate are also outlined. In particular, the following specific topics are analyzed: (i) the relationship between textural and reactivity properties. (ii) the problem of the design of samples with improved DeSOx properties in relation to the stability of the samples over extended operations, and (iii) the optimization of the regeneration characteristics of the samples. Details on the flow sheet of the technology are also given.

scholarly journals Analysis and assessment of water treatment plant reliability

2017 ◽  
Vol 41 (1) ◽  
pp. 21-38
Author(s):  
Dawid Szpak ◽  
Barbara Tchórzewska-Cieślak
Keyword(s):  
Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Parameter Method ◽  
Flow Sheet ◽  
Surface Water Treatment ◽  
The Subject ◽  
Availability Index ◽  
The One ◽  
The Individual

Abstract The subject of the publication is the analysis and assessment of the reliability of the surface water treatment plant (WTP). In the study the one parameter method of reliability assessment was used. Based on the flow sheet derived from the water company the reliability scheme of the analysed WTP was prepared. On the basis of the daily WTP work report the availability index Kg for the individual elements included in the WTP, was determined. Then, based on the developed reliability scheme showing the interrelationships between elements, the availability index Kg for the whole WTP was determined. The obtained value of the availability index Kg was compared with the criteria values.

Extraction of Dithiocarbamate Chelates of Ni(II), Cu(II), Zn(II)

1996 ◽  
Vol 61 (5) ◽  
pp. 673-680
Author(s):  
Drahomír Oktavec ◽  
Jozef Lehotay ◽  
Viktor Vrábel ◽  
Elena Korgová
Keyword(s):  
Strong Acid ◽  
Optimum Conditions ◽  
Time Intervals ◽  
Acid Media ◽  
Ph Values ◽  
Quantitative Extraction ◽  
Maximum Extraction ◽  
Short Time ◽  
Alkali Salts ◽  
Acid Region

Extraction has been investigated of chelates of alkali salts of dithiocarbamic (DTC) acids derived from (R-) dimethyl-, diethyl-, dipropyl-, diisopropyl-, dibutyl-, diisobutyl-, dipentyl-, and dihexylamine, piperidine, and morpholine with Ni(II), Cu(II), and Zn(II) from aqueous solutions of various pH values into chloroform for various time intervals. The optimum conditions have been determined for the maximum extraction yields of the metal connected with the minimum extraction yields of excess DTC ligand. The extraction of DTC chelates of Ni(II), Cu(II), and Zn(II) is best accomplished in a reaction period of 4.5 min in strong acid region (Ni, Cu) or in alkaline region with buffers of pH 8.5-9.0 (Zn). The advantage of DTC as compared with many other reagents lies in the possibility of quantitative extraction of Ni(II) and Cu(II) from strong acid media since in this region the excess DTC ligand is completely decomposed to carbon disulfide and amine in short time, and thus it does not interfere with the subsequent spectrophotometric determination.

Partitioning Contrast or Luminance Disparity into Perceived Intensity and Rotation

2011 ◽  
Vol 24 (4) ◽  
pp. 315-350 ◽  
Author(s):  
Richard Hetley ◽  
Wm Wren Stine
Keyword(s):  
Degrees Of Freedom ◽  
Gain Control ◽  
Control Model ◽  
Two Stage ◽  
Rectangular Wave ◽  
Perceived Intensity ◽  
The Difference ◽  
The Individual ◽  
Simple Difference ◽  
Intensity Contrast

AbstractWhile most of the work on stereopsis focuses on geometric disparities, humans also respond to intensity (contrast or luminance) disparities in the absence of geometric disparities. A rectangular-wave grating viewed with an intensity disparity engenders two perceptions: a perceived intensity, and a perceived rotation of the individual bars of the grating (the Venetian blind effect). Measuring perceived intensity and perceived rotation in gratings with intensity disparities, we found that the two degrees of freedom from the intensities presented to each eye are conserved in the form of two perceptions: perceived intensity is related to the sum of the grating intensities and perceived rotation is related to the difference. Perceived rotation as a function of intensity disparity was then modeled as a simple difference in the neural response of each eye. Perceived contrast and brightness as a function of intensity disparity were modeled using the two-stage gain-control model.

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