Process and kinetics of the selective extraction of cobalt from high-silicon low-grade cobalt ores using ammonia leaching

Ammonia leaching is a promising method for processing low-grade copper ores, especially those containing large amounts of oxidized copper. In this paper, we study the effect of Si-containing minerals on the kinetics of Cu and Ag leaching from low-grade copper concentrates. The results of experiments on the pressure leaching of the initial copper concentrate in an ammonium/ammonium-carbonate solution with oxygen as an oxidizing agent are in good agreement with the shrinking core model in the intra-diffusion mode: in this case, the activation energies were 53.50 kJ/mol for Cu and 90.35 kJ/mol for Ag. Energy-dispersive X-ray spectroscopy analysis (EDX) analysis showed that reagent diffusion to Cu-bearing minerals can be limited by aluminosilicate minerals of the gangue. The recovery rate for copper and silver increases significantly after a preliminary alkaline desilication of the concentrate, and the new shrinking core model is the most adequate, showing that the process is limited by diffusion through the product layer and interfacial diffusion. The activation energy of the process increases to 86.76 kJ/mol for Cu and 92.15 kJ/mol for Ag. Using the time-to-a-given-fraction method, it has been shown that a high activation energy is required in the later stages of the process, when the most resistant sulfide minerals of copper and silver apparently remain.

Download Full-text

Ammonia Leaching of Zinc from Low-grade Oxide Zinc Ores Using the Enhancement of the Microwave Irradiation

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2017-0055 ◽

2017 ◽

Vol 16 (3) ◽

Author(s):

Shiwei Li ◽

Haoyu Li ◽

Weiheng Chen ◽

Jinhui Peng ◽

Aiyuan Ma ◽

...

Keyword(s):

Phase Transformation ◽

Microwave Irradiation ◽

Solid Phase ◽

Ammonia Concentration ◽

Low Grade ◽

Leaching Rate ◽

Small Particles ◽

Mineral Phase ◽

Total Ammonia ◽

Ammonia Leaching

AbstractIrradiated roast treatment and the ammonia leaching processing were conducted to deal with the low-grade oxide zinc ores. The ZnCO3phase was hard to be attended, which was the reason for the low leaching rate of the complicated zinc ores. The mineral phase transformation of the ZnCO3phase was generated after the ores irradiated in the microwave at the temperature of 673 K. The irradiated ores generated more small particles, it was the reason that the leaching rate of the complicated zinc ores was increased. When the leaching processing of the irradiated roasted ores was conducted under the conditions of the total ammonia concentration of 6 mol/L, the liquid to solid phase ratio of 11:1, the leaching temperature of 298 K, the leaching time of 150 min and the stirring speed of 400 rpm, 88.3 % of zinc could be achieved, which was the maximum leaching rate of the irradiated ores.

Download Full-text

Kinetics of Ammonia Leaching of Multimetal Sulphides

Mineral Processing and Extractive Metallurgy Review ◽

10.1080/08827509208914072 ◽

1992 ◽

Vol 10 (1) ◽

pp. 11-27 ◽

Cited By ~ 7

Author(s):

K. SARVESWARA RAO ◽

S. ANAND ◽

R. P. DAS ◽

H. S. RAY

Keyword(s):

Ammonia Leaching ◽

Kinetics Of

Download Full-text

Differential kinetics of α-[11C]methyl-l-tryptophan on PET in low-grade brain tumors

Journal of Neuro-Oncology ◽

10.1007/s11060-010-0327-1 ◽

2010 ◽

Vol 102 (3) ◽

pp. 409-415 ◽

Cited By ~ 23

Author(s):

Csaba Juhász ◽

Otto Muzik ◽

Diane C. Chugani ◽

Harry T. Chugani ◽

Sandeep Sood ◽

...

Keyword(s):

Brain Tumors ◽

Low Grade ◽

Kinetics Of

Download Full-text

Leaching Kinetics of Lanthanide in Sulfuric Acid from Low Grade Bauxite

Materials Today Proceedings ◽

10.1016/j.matpr.2019.06.213 ◽

2019 ◽

Vol 18 ◽

pp. 462-467 ◽

Cited By ~ 1

Author(s):

Eny Kusrini ◽

Anwar Usman ◽

Nici Trisko ◽

Sri Harjanto ◽

Arif Rahman

Keyword(s):

Sulfuric Acid ◽

Low Grade ◽

Leaching Kinetics ◽

Kinetics Of

Download Full-text

Dissolution Reactivity and Kinetics of Low-Grade Limestone for Wet Flue Gas Desulfurization

Industrial & Engineering Chemistry Research ◽

10.1021/acs.iecr.0c01896 ◽

2020 ◽

Vol 59 (32) ◽

pp. 14242-14251 ◽

Cited By ~ 1

Author(s):

Shuaiwei Gu ◽

Zhizhong Yang ◽

Zhen Chen ◽

Changfu You

Keyword(s):

Flue Gas ◽

Flue Gas Desulfurization ◽

Low Grade ◽

Kinetics Of

Download Full-text

Impacts of ultrasound on leaching recovery of zinc from low grade zinc oxide ore

Green Processing and Synthesis ◽

10.1515/gps-2015-0036 ◽

2015 ◽

Vol 4 (4) ◽

Author(s):

Shiwei Li ◽

Weiheng Chen ◽

Shaohua Yin ◽

Aiyuan Ma ◽

Kun Yang ◽

...

Keyword(s):

Zinc Oxide ◽

Ammonia Concentration ◽

Low Grade ◽

Total Ammonia ◽

Ammonia Leaching

AbstractOn the basis of an experiment on ultrasonic enhanced ammonia leaching of low grade zinc oxide ores, the effects of the total ammonia concentration, the ratio between the NH

Download Full-text

Leaching and Kinetic Modeling of Malaysian Low Grade Manganese Ore in Sulfuric Acids

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1133.629 ◽

2016 ◽

Vol 1133 ◽

pp. 629-633 ◽

Cited By ~ 2

Author(s):

Suhaina Ismail ◽

Hashim Hussin ◽

Syed Fuad Saiyid Hashim ◽

Norazharuddin Shah Abdullah

Keyword(s):

Dissolution Kinetics ◽

Product Layer ◽

Low Grade ◽

Manganese Ore ◽

Leaching Process ◽

Mixed Control ◽

New Variant ◽

Experimental Parameters ◽

Kinetics Of ◽

And Diffusion

The leaching process of Malaysian low grade manganese ore (LGMO) using bamboo sawdust (BSD) as reducing agent in acidic medium (H2SO4) and the dissolution kinetics of this ore was investigated. Acid concentration, reaction temperature, and BSD loading were chosen as experimental parameters through application of response surface methodology (RSM). For analysis of the kinetic data in this study, the SCM with surface chemical reaction and diffusion through product layer, the mixed control modelled and also new variant SCM were evaluated. The reaction kinetics of this leaching process was determined, and it is observed that it fits the model of 1-23X-(1-X)23=kt with activation energy of 69.3kJ/mol. The reaction rate for LGMO leaching using BSD was found to be diffusion through product layer.

Download Full-text