scholarly journals Ammoniacal Solvoleaching of Copper from High-Grade Chrysocolla

2020 ◽  
Vol 6 (4) ◽  
pp. 589-598
Author(s):  
Lukas Gijsemans ◽  
Joris Roosen ◽  
Sofía Riaño ◽  
Peter Tom Jones ◽  
Koen Binnemans
Keyword(s):  
Silica Gel ◽  
Aqueous Ammonia ◽  
Acid Leaching ◽  
Leach Solution ◽  
Phase System ◽  
Flow Sheet ◽  
High Grade ◽  
Gel Formation ◽  
Metallurgical Processing ◽  
Three Phase

AbstractThe copper silicate ore chrysocolla forms a large potential copper resource, which has not yet been fully exploited, due to difficulties associated with its beneficiation by flotation and metallurgical processing. Direct acid leaching of chrysocolla causes silica gel formation. Therefore, in this work, the feasibility of solvometallurgical methods to leach copper from high-grade chrysocolla while avoiding issues with silica gel formation was assessed. Ammoniacal solvoleaching was performed with a solvent comprising the chelating extractant LIX 984 N or the acidic extractant Versatic acid 10 in an aliphatic diluent (ShellSol D70 or GTL Fluid G70), combined with a small volume of aqueous ammonia. In the three-phase system, aqueous ammonia dissolves copper from milled and sieved chrysocolla, while copper is simultaneously extracted to the organic phase, releasing ammonia that can be reused for further extraction. The best results were obtained with LIX 984 N as extractant: using a 50 vol% LIX 984 N solution, about 75% of copper could be extracted after 60 min of leaching at 25 °C. The stripping of copper from the pregnant leach solution was optimized. Quantitative stripping of copper was achieved with 1.89 M sulfuric acid and the final aqueous solution of copper sulfate had a concentration of 33 g L−1. Experiments in a leaching reactor (1 L) and small battery of mixer-settlers (3 stages, 35 and 143 mL effective volume in the mixer and the settler, respectively, per stage) were successfully conducted and allowed to recover copper with a purity of 99.9%. A conceptual flow sheet has been developed. Graphical Abstract

scholarly journals Preliminary Study on Gold Recovery from High Grade E-Waste by Thiourea Leaching and Electrowinning

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 235
Author(s):  
Nicolò Maria Ippolito ◽  
Ionela Birloaga ◽  
Francesco Ferella ◽  
Marcello Centofanti ◽  
Francesco Vegliò
Keyword(s):  
Sulfuric Acid ◽  
Leach Solution ◽  
High Grade ◽  
Gold Dissolution ◽  
Plastic Part ◽  
The Third ◽  
Current Consumption ◽  
Different Types ◽  
Preliminary Study ◽  
A Current

The present paper is focused on the extraction of gold from high-grade e-waste, i.e., spent electronic connectors and plates, by leaching and electrowinning. These connectors are usually made up of an alloy covered by a layer of gold; sometimes, in some of them, a plastic part is also present. The applied leaching system consisted of an acid solution of diluted sulfuric acid (0.2 mol/L) with thiourea (20 g/L) as a reagent and ferric sulfate (21.8 g/L) as an oxidant. This system was applied on three different high-grade e-waste, namely: (1) Connectors with the partial gold-plated surface (Au concentration—1139 mg/kg); (2) different types of connectors with some of which with completely gold-plated surface (Au concentration—590 mg/kg); and (3) connectors and plates with the completely gold-plated surface (Au concentration—7900 mg/kg). Gold dissolution yields of 52, 94, and 49% were achieved from the first, second, and third samples, respectively. About 95% of Au recovery was achieved after 1.5 h of electrowinning at a current efficiency of only 4.06% and current consumption of 3.02 kWh/kg of Au from the leach solution of the third sample.

scholarly journals Hardware for classification of power quality problems in three phase system using Microcontroller

2017 ◽  
Vol 4 (1) ◽  
pp. 1386364 ◽  
Author(s):  
S. Asha Kiranmai ◽  
A. Jaya Laxmi ◽  
Qingsong Ai
Keyword(s):  
Power Quality ◽  
Phase System ◽  
Three Phase

Effects of Magnetic Treatment Water on Silica Gel Formation

2016 ◽  
Vol 45 (10) ◽  
pp. 1192-1194
Author(s):  
Keiichiro Kaida ◽  
Shigeo Sasahara ◽  
Atom Hamasaki ◽  
Sumio Ozeki
Keyword(s):  
Silica Gel ◽  
Magnetic Treatment ◽  
Gel Formation ◽  
Treatment Water

Activity coefficients, densities, dipole moments, and surface tensions of the system triethylamine–methylethylketone–water

1981 ◽  
Vol 59 (1) ◽  
pp. 127-131 ◽  
Author(s):  
Alan N. Campbell
Keyword(s):  
Surface Layer ◽  
Dipole Moments ◽  
Phase System ◽  
Constant Composition ◽  
Two Phase ◽  
Three Phase ◽  
Wide Range ◽  
Isothermal System ◽  
Total Composition ◽  
Two Phases

The properties named in the title have been determined by standard methods. Viscosity, molar volume, and orientation polarisation all indicate abnormalities of the nature of association between the components.The most interesting result is that of surface tension which indicates that, in the case of the binary system triethylamine–water, a surface layer of constant composition is formed over a wide range of total composition. When, by a rise in temperature of two or three degrees, this layer becomes unstable, it splits into two phases of different composition. The surface layer may then be instantaneously reformed and so on. A mechanism for the generation of a two-phase system is thus established. The data for the three-phase, isothermal, system are not so convincing, for reasons that are suggested.

Synthesis of Magnesia Powder from East Java Dolomite through Leaching, Precipitation and Calcination

2015 ◽  
Vol 1112 ◽  
pp. 550-554
Author(s):  
M. Zaki Mubarok ◽  
Christian Adi Kurniawan
Keyword(s):  
Particle Diameter ◽  
Acid Leaching ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Leach Solution ◽  
Water Removal ◽  
Solution Ph ◽  
Crystal Water ◽  
Lower Temperature ◽  
Co Precipitation

At the present paper, a process of magnesia (MgO) synthesis from East Java dolomite through hydrochloride acid leaching, precipitation and calcination as well as characteristic of the product is discussed. Results of the experimental works show that the dissolution rate of magnesium and calcium from dolomite in hydrochloride acid solution was very rapid. Complete magnesium extraction was obtained by the leaching test with acid concentration of 1.5 molar, particle size distribution of -325#, solid-liquid ratio 1:20 (g/mL), stirring speed 200 rpm at room temperature after only 10 seconds. Precipitation of Mg(OH)2 by the addition of 20% (v/v) CaO slurry into pregnant leach solution resulted in 97.5% Mg precipitation after 1 minute. Solution pH must be maintained at a level of 10-10.5 by adjusting CaO addition in order to minimize calcium co-precipitation and to obtain high purity of Mg(OH)2 precipitate. Calcinations of Mg(OH)2 were performed at temperature range of 550-800°C in which 99% of crystal water removal took place after 5 minute at temperature of 800°C. Lower temperature requires longer time of crystalline water removal from Mg(OH)2. XRF analysis showed MgO purity of 88% with the main impurities of calcium and chloride. XRD analysis detected the presences of calcium as calcite (CaCO3) and portlandite (Ca(OH)2) as impurities in the MgO product. SEM analysis of the MgO powder revealed a nano size of MgO with particle diameter of about 50 nm.

Thermodynamics of the particle consolidation in a three-phase system

2007 ◽  
Vol 29 (4) ◽  
pp. 224-227 ◽  
Author(s):  
A. F. Lisovskii
Keyword(s):  
Phase System ◽  
Three Phase

Influence of biomass on hydrodynamics of an internal loop airlift reactor

2006 ◽  
Vol 60 (6) ◽  
Author(s):  
M. Juraščík ◽  
M. Hucík ◽  
I. Sikula ◽  
J. Annus ◽  
J. Markoš
Keyword(s):  
Aspergillus Niger ◽  
Gluconic Acid ◽  
Solid Phase ◽  
Biomass Concentration ◽  
Airlift Reactor ◽  
Phase System ◽  
Two Phase ◽  
Experimental Conditions ◽  
Internal Loop ◽  
Three Phase

AbstractThe effect of the biomass presence on the overall circulation velocity, the linear velocities both in the riser and the downcomer and the overall gas hold-up was studied in a three-phase internal loop airlift reactor (ILALR). The measured data were compared with those obtained using a two-phase system (air—water). All experiments were carried out in a 40 dm3 ILALR at six different biomass concentrations (ranging from 0 g dm−3 to 7.5 g dm−3), at a temperature of 30°C, under atmospheric pressure. Air and water were used as the gas and liquid model media, respectively. Pellets of Aspergillus niger produced during the fermentation of glucose to gluconic acid in the ILALR were considered solid phase. In addition, liquid velocities were measured during the fermentation of glucose to gluconic acid using Aspergillus niger. All measurements were performed in a bubble circulation regime. At given experimental conditions the effect of the biomass on the circulation velocities in the ILALR was negligible. However, increasing of the biomass concentration led to lower values of the total gas hold-up.

scholarly journals Muscle: A Three Phase System

1959 ◽  
Vol 43 (1) ◽  
pp. 55-79 ◽  
Author(s):  
Shirley E. Simon ◽  
B. M. Johnstone ◽  
K. H. Shankly ◽  
F. H. Shaw
Keyword(s):  
Steady State ◽  
Sartorius Muscle ◽  
Phase System ◽  
Extracellular Material ◽  
Foreign Ions ◽  
Three Phase ◽  
Na Efflux ◽  
Muscle Water ◽  
Toad Bufo ◽  
Normal Controls

The partition of Li+, Br-, and I- across the membrane of the sartorius muscle of the toad Bufo marinus has been investigated both at the steady state and with kinetic methods. Li+ was found to have access to an amount of muscle water similar to that of Na+. Br- and I- could be regarded as being interchangeable with cellular Cl-. None of the foreign ions caused significant losses of cellular K+. Li+ efflux from the cell was slower in muscles which were equilibrated for long periods in Li+ than in short equilibrated muscles. Na+ efflux from Li+-treated muscles was similar in rate to normal controls, but the amount of Na+ in the slow fraction was increased by Li+. I- efflux was extremely rapid, and it was not possible to differentiate kinetically between intra- and extracellular material. These results have been found to be consistent with the hypothesis of a three phase system for muscle.

Oxidation of 2,3,6-trimethylphenol to 2,3,5-trimethyl-1,4-benzoquinon over binary xerogels TiO2—SiO2 in the three-phase system

2017 ◽  
Vol 66 (4) ◽  
pp. 677-682 ◽  
Author(s):  
Yu. V. Mikushina ◽  
A. B. Shishmakov ◽  
L. A. Petro
Keyword(s):  
Phase System ◽  
Three Phase
Sign in / Sign up

Export Citation Format

Share Document