scholarly journals Leaching Kinetics of Secondary Zinc Oxide in a NH3–NH4HCO3–H2O System

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 496
Author(s):  
Hui Li ◽  
Linfei Zhao ◽  
Le Wang ◽  
Jinglong Liang ◽  
Hongyan Yan ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Recovery Process ◽  
Ammonia Concentration ◽  
Product Layer ◽  
Ammonium Bicarbonate ◽  
Zinc Recovery ◽  
Solid Ratio ◽  
Total Ammonia ◽  
Hydrometallurgical Method ◽  
Kinetics Of

Secondary zinc oxide (SZO), which comes from the zinc industry, is an important secondary resource of zinc and other valuable metals. In this study, the production feasibility and rationality of a cleaner zinc recovery process using SZO and a hydrometallurgical method were described. Zinc extraction is promoted by the addition of ammonium bicarbonate to a NH3–H2O system, and the maximum recovery of zinc could be close to 80% at the optimum leaching conditions of a stirring rate of 400 rpm, an ammonia/ammonium ratio of 7:3, a total ammonia concentration of 4 mol/L, and a liquid/solid ratio of 7 mL/g for 30 min at 35 °C. The kinetics of leaching were modeled using the shrinking core model of constant-size particles, and the rate-controlling step was determined to be the diffusion through the product layer. The apparent activation energy of the reaction was estimated to be 11.04 KJ·mol−1, while the order of reaction with respect to total ammonia concentration was 1.53 and the liquid/solid ratio was 2.26. The analysis results of the initial residue and the leached residue indicated that lead was transferred from PbCl2 to PbCO3 and that ZnFe2O4 was not leached in the NH3-NH4HCO3-H2O system.

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

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

scholarly journals Dissolution Kinetics of Ilmenite Ore in A Binary Solution

2019 ◽  
Vol 4 (7) ◽  
pp. 51-57
Author(s):  
Chukwunonso Chukwuzuloke Okoye ◽  
Okechukwu Dominic Onukwuli ◽  
Chinenye Faith Okey-Onyesolu
Keyword(s):  
Particle Size ◽  
Acid Concentration ◽  
Reaction Temperature ◽  
Binary Solution ◽  
Product Layer ◽  
Solution Temperature ◽  
X Ray ◽  
Solid Ratio ◽  
Oxidant Concentration ◽  
Kinetics Of

Leaching of iron from ilmenite ore using a binary solution (HCl-NaNO3) was investigated. The raw ilmenite ore sample was characterized using Scanning Electron Microscopy (SEM), X-ray diffraction spectroscopy (XRD) and X-ray Flourescence (XRF) techniques. The influence of acid concentration, oxidant concentration, particle size, solution temperature, stirring speed and liquid-to-solid ratios on the extent of dissolution was examined. The experimental data obtained at various process parameter conditions were tested in six kinetics models: shrinking core model’s diffusion through liquid film model(DTLF), diffusion through product layer model (DTPL), surface chemical reaction model (SCR)); mixed kinetics model (MKM), Jander (three dimensional) model and Kröger and Ziegler model. The crystalline morphology of the sample was displayed by the SEM micrograph. XRF result revealed the dominance of titanium and iron in ilmenite while XRD confirmed that ilmenite exist mainly as FeTiO2. The results of the leaching studies showed that ilmenite dissolution in the binary solution increases with increasing acid concentration, oxidant concentration, reaction temperature, stirring speed and liquid-to-solid ratio; while it decreases with particle size. The study showed that 94.77% iron was dissolved by 1MHCl-0.6M NaNO3 at 75μm particle size, 75˚C reaction temperature, 300rpm stirring speed and 30L/g liquid-to-solid ratio. The kinetics of the leaching process was best described by Kröger and Ziegler model with diffusion through the product layer as rate controlling step. The activation energy, Ea, was calculated to be 6.42kJ/mol. The results indicate that HCl-NaNO3 binary solution can be used as an effective lixiviant for extracting iron from ilmenite ores.

scholarly journals Zinc recovery from metallurgical slag and dust by coordination leaching in NH 3 –CH 3 COONH 4 –H 2 O system

2018 ◽  
Vol 5 (7) ◽  
pp. 180660 ◽  
Author(s):  
Aiyuan Ma ◽  
Xuemei Zheng ◽  
Song Li ◽  
Yihong Wang ◽  
Shan Zhu
Keyword(s):  
Recovery Process ◽  
Ammonia Concentration ◽  
Metallurgical Slag ◽  
Galvanized Steel ◽  
Mass Spectrometry Analysis ◽  
Steel Scrap ◽  
Ionization Mass ◽  
Zinc Recovery ◽  
Spectrometry Analysis ◽  
Secondary Sources

Metallurgical slag and dust (MSD) from lead and zinc smelting, steel dust and galvanized steel scrap are important secondary sources of zinc and other valuable metals. This paper describes the production feasibility and rationality of a cleaner zinc recovery process using MSD and a hydrometallurgical method. It was found that the addition of CH 3 COONH 4 to a NH 3 –H 2 O system promotes zinc extraction, and 83.76% of zinc could be dissolved and recovered from the MSD under the following conditions: total ammonia concentration of 5 mol l −1 , stirring speed of 300 r.p.m., ammonia/ammonium ratio of 1 : 1, solid/liquid ratio of 1 : 5, leaching temperature of 25°C and a leaching time of 60 min. A leaching kinetic study indicates that the leaching process is controlled by the diffusion and interface transfer and that the reaction apparent activation energy is 22.66 kJ mol −1 . Fourier transform infrared spectroscopy and electrospray ionization mass spectrometry analysis showed that zinc can combine with the carboxylate anion to form Zn complexes such as [Zn 2 (Ac) 3 (NH 3 ) 2 ] + . Zn 2 SiO 4 , ZnS and ZnFe 2 O 4 in NH 3 –CH 3 COONH 4 –H 2 O system did not disappear according to X-ray diffraction analysis for leaching residue.

Influence of Important Factors on Ammonia Leaching of Alkaline Zinc Oxide Mineral

2013 ◽  
Vol 785-786 ◽  
pp. 1076-1080
Author(s):  
Xiao Dong Jia ◽  
Zhi Cong Wei ◽  
Dian Wen Liu ◽  
Jing Jie Yuan
Keyword(s):  
Zinc Oxide ◽  
Yunnan Province ◽  
Ammonia Concentration ◽  
Ammonium Bicarbonate ◽  
Leaching Rate ◽  
Optimum Conditions ◽  
Liquid Ratio ◽  
Oxide Mineral ◽  
Ammonia Leaching

The effects of refractory zinc oxide ore which came from Lanping of Yunnan Province were studied using agitation leach method in laboratory in order to find out the optimum leaching conditions. The optimum conditions obtained are as follows: ammonia concentration 3mol/L, ammonium bicarbonate 1.5mol/L, granularity (-0.074mm) about 85%, solid to liquid ratio 4:1, and leaching time 2h. On this condition, the test obtained the better index of the zinc leaching rate 74.4%.

scholarly journals Properties and Kinetics of Selective Zinc Leaching with Choline Chloride and Urea

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 857
Author(s):  
Jinxia Zhang ◽  
Jiajing Dong ◽  
Fusheng Niu ◽  
Chao Yang
Keyword(s):  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Zinc Content ◽  
Product Layer ◽  
Layer Formation ◽  
Solid Product ◽  
Solid Ratio ◽  
Secondary Recovery ◽  
Kinetics Of ◽  
Leaching Efficiency

A choline chloride-urea (ChCl-urea) deep eutectic solvent (DES) was used to experimentally investigate the secondary recovery of zinc from zinc-bearing dust sludge via a leaching process. The effects of varying the liquid–solid ratio, leaching temperature, stirring speed, and leaching time on the zinc leaching efficiency were determined, and the optimum values of these parameters were found to be 15:1, 90 °C, 400 rpm, and 600 min, respectively, at which a leaching efficiency of 86.87% was achieved. XRF and EDS analyses confirmed that the zinc content in the sludge decreased noticeably after leaching, while those of other elements did not, indicating the selective and efficient leaching of zinc. A study of the leaching kinetics showed that the reaction conforms to the nuclear shrinkage model without solid product layer formation, and the calculated apparent activation energy is 22.16 kJ/mol.

scholarly journals Intercalated cell-specific Rh B glycoprotein deletion diminishes renal ammonia excretion response to hypokalemia

2013 ◽  
Vol 304 (4) ◽  
pp. F422-F431 ◽  
Author(s):  
Jesse M. Bishop ◽  
Hyun-Wook Lee ◽  
Mary E. Handlogten ◽  
Ki-Hwan Han ◽  
Jill W. Verlander ◽  
...  
Keyword(s):  
Metabolic Acidosis ◽  
Collecting Duct ◽  
Ammonia Excretion ◽  
Ammonia Concentration ◽  
Intercalated Cells ◽  
Cortical Collecting Duct ◽  
Intercalated Cell ◽  
Transporter Family ◽  
Total Ammonia ◽  
Normal Increase

The ammonia transporter family member, Rh B Glycoprotein (Rhbg), is an ammonia-specific transporter heavily expressed in the kidney and is necessary for the normal increase in ammonia excretion in response to metabolic acidosis. Hypokalemia is a common clinical condition in which there is increased renal ammonia excretion despite the absence of metabolic acidosis. The purpose of this study was to examine Rhbg's role in this response through the use of mice with intercalated cell-specific Rhbg deletion (IC-Rhbg-KO). Hypokalemia induced by feeding a K+-free diet increased urinary ammonia excretion significantly. In mice with intact Rhbg expression, hypokalemia increased Rhbg protein expression in intercalated cells in the cortical collecting duct (CCD) and in the outer medullary collecting duct (OMCD). Deletion of Rhbg from intercalated cells inhibited hypokalemia-induced changes in urinary total ammonia excretion significantly and completely prevented hypokalemia-induced increases in urinary ammonia concentration, but did not alter urinary pH. We conclude that hypokalemia increases Rhbg expression in intercalated cells in the cortex and outer medulla and that intercalated cell Rhbg expression is necessary for the normal increase in renal ammonia excretion in response to hypokalemia.

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

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.

Investigation of the Kinetics of Sulfite Oxidation on by-Production Recovery Process in WFGD

2012 ◽  
Vol 610-613 ◽  
pp. 1980-1985 ◽  
Author(s):  
Hong Jian Xu ◽  
Shu Fang Wang ◽  
Wei Guo Pan ◽  
Rui Tang Guo
Keyword(s):  
Chemical Reaction ◽  
Oxidation Kinetics ◽  
Reaction Rate ◽  
Recovery Process ◽  
Orthogonal Test ◽  
Sulfite Oxidation ◽  
Air Ventilation ◽  
Kinetics Of

The limestone-lime washing technology is the most widely used WFGD process, which normally we adopt to control the discharge of SO2 caused by coal’s combustion. Through the research on the oxidation kinetics of sulfite in this paper, it is indicated that macroscopic chemical reaction which responses to rate of sulfite is 1/2. And the results of orthogonal test can be concluded that: to the extent influence of oxidization reaction rate, the influences of temperature is the most significant, and influences of stirred speed is nearly negligible. The optimized operation factors may be shown as that temperature is controlled at 40°C, air ventilation is at 88ml/min,pH is 4.5 and stir speed is 500 r/min.

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