Leaching of oxidic zinc materials with chlorine and chlorine hydrate

Thomas, B. K.; Fray, Derek J.

doi:10.1007/bf02654461

Cited by 19 publications

(11 citation statements)

References 1 publication

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“…The sample has been added to the solution in 1/10 solid/liquid mass ratio, and stirred for more than 2 h at around 200 rpm. Considering zinc ferrite as the main phase of EAF dust, and also that only those metals whose chlorides were more stable than their oxides could be leached, the leaching should occur according to the reaction 5) :…”

Section: Samples and Methodsmentioning

confidence: 99%

“…1,5,6) The morphological feature of the EAF dust after the leaching treatment (loosely aggregated) has provided further information in this regard. SEM pictures of the above samples are treated by image analysis, using Heywod approximation, to get the EAF dust particle size distribution (Fig.…”

Section: Morphological and Chemical Analysesmentioning

confidence: 99%

“…5,6) Such wide particle size range implies that any study involving EAF dust collection has to consider both over-micron and nano-scale particles. The physical situation of the EAF dust injection in a coke bed is similar to the pulverized coal or fine ore injection in the blast furnace.…”

Section: Introductionmentioning

confidence: 99%

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Mathematical Model of Over-micron and Nano-scale Powders Accumulation in a Coke Fixed-Bed Filter

et al. 2005

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The advances in Electric Arc Furnace (EAF) dust treatment have been slowed down by high treatment costs and the large amount of residue to be processed and disposed. A process of direct separation and recovery of iron and zinc is now under development, which adds environmental and economical perspectives to the EAF dust treatment process. In this process, a coke bed filter can be directly connected to an EAF, collecting metallic iron and slag components, whereas the gas containing zinc and lead vapors flows to a zinc condenser. It results in zero amount of dust liberated to the environment. A two dimensional, axisymmetric and steady state mathematical model describing a coke fixed-bed filter is developed. The model solves coupled equations for gas-powder flow and is specifically applied in the investigation of over-micron and nano-scale powders (similar to EAF dust particle size) collection behavior. The theoretical model results are compared with the cold model experimental results, in which both injection of glass (over-micron) and silica (nano-scale) powders are considered. Microscopic observations and analysis are performed in order to describe better the injected powder behavior through the filter. EAF dust samples morphology is characterized as agglomerates of small particles. Its particle size distribution is obtained by the combination of leaching treatment and image analysis. Calculated results show that the powders particle size distribution has a direct effect in the static hold up. The model has been validated by its enough agreement for static hold up and pressure drop with experimental data from cold model experiments.KEY WORDS: mathematical model; Electric Arc Furnace; dust treatment; environment; packed bed; filter.have advanced for more detailed investigations, e.g. including the effect of the temperature, 23) the presence of an electrified field, 24) or the effect of the aerosol deposition on the filtration. 25) A model equation adapted from the theory for a fibrous filter, describing the dust load distribution in a coke bed filter, has also been recently developed and tested. 26)The aim of this research is contribute to the development and improvement of the process of direct separation and recovery of iron and zinc, testing and analyzing its efficiency and effectiveness. The physical modeling of the packed bed filter had provided a series of experimental results about pressure drop and the powder collection. [27][28][29][30][31][32] In this work a mathematical model of a cold coke fixed-bed filter has been developed. This model is used to investigate the powder accumulation behavior and pressure drop with the injection of over-micron and nano-scale powders in a packed bed. The mathematical model developed here is expected to be the framework for simulation of a high-temperature coke fixedbed filter and further on to study different aspects of this process. Microscopic Observations and AnalysisDue to lack of information about aerosol collection in packed bed filters, including the theoretical ...

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Section: Samples and Methodsmentioning

confidence: 99%

Section: Morphological and Chemical Analysesmentioning

confidence: 99%

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Mathematical Model of Over-micron and Nano-scale Powders Accumulation in a Coke Fixed-Bed Filter

et al. 2005

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“…Thomas [22] investigated zinc oxide ore leaching with chlorine and chlorine hydrate, and found that the leaching rate was controlled by surface reaction. In another study, the application of organic acid as leaching reagent was investigated.…”

Section: Introductionmentioning

confidence: 99%

Dissolution Kinetics of Zinc Oxide Ore with an Organic Acid

Deng¹,

Sun²,

Lin³

et al. 2015

Int J Metall Mater Eng

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In this study, the dissolution kinetics of smithsonite as an alternative zinc source in trichloroacetic acid (TCA) solution was investigated. TCA can be derived from industrial waste acid in the pharmaceutical, biotechnology and chemical fields. Results showed that the dissolution kinetics conformed to the shrinking core model controlled by surface chemical reaction. The apparent activation energy of the reaction was calculated as 47.61 kJ/mol, indicating the obvious effect of temperature on the reaction rate. The reaction kinetic equation associated with the main influencing factors was eventually established as 1-(1-x) -1/3 = [0.0002 (C) 0.384 (P) 0.969 exp(-5726T)] t. The high reaction speed of smithsonite in TCA solution shows that TCA has a dissolution effect on zinc oxide ores; thus, it can be employed as an advantageous organic leaching reagent environmentally friendly. In addition, the experimental parameters obtained provide basic data and reference for the leaching of other carbonate minerals of copper, zinc, lead and cobalt, among others, in an organic acid system.

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“…[1][2][3][4][5][6][7][8] Zinc is one of the most used nonferrous metals; it has applications mainly in construction for corrosion protection and in pressure die casting of complex components. Zinc-based chemicals, among which zinc oxide is the most relevant one, are used in a wide range of fields, including production of other chemicals; the rubber industry; the manufacture of paints; agriculture; the glass, enamel, and ceramic industries; cosmetics; as an additive to lubricants, adhesives, and drying agents; and as a catalyst in methanol synthesis.…”

Section: Introductionmentioning

confidence: 99%

Chlorination of Zinc Oxide between 723 and 973 K

Micco

Fouga

Bohé

2007

Metall Mater Trans B

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The kinetics of the chlorination of zinc oxide has been studied by thermogravimetry between 723 and 973 K. The starting temperature for the reaction of ZnO with chlorine is determined at about 498 K. The influence of gaseous flow rate, sample mass, temperature, and chlorine partial pressure in the reaction rate is analyzed. It is established that the reaction occurs under mixed control, being pore diffusion coupled with chemical reaction as the rate controlling step. An apparent reaction order of 0.5 with respect to chlorine partial pressure was determined. A kinetic model for the chlorination reaction of porous solids under mixed control determined an intrinsic reaction order of zero with respect to partial pressure of chlorine and an intrinsic activation energy of 249 kJ mol -1 .

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Leaching of oxidic zinc materials with chlorine and chlorine hydrate

Cited by 19 publications

References 1 publication

Mathematical Model of Over-micron and Nano-scale Powders Accumulation in a Coke Fixed-Bed Filter

Mathematical Model of Over-micron and Nano-scale Powders Accumulation in a Coke Fixed-Bed Filter

Dissolution Kinetics of Zinc Oxide Ore with an Organic Acid

Chlorination of Zinc Oxide between 723 and 973 K

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