Factors Affecting Fluoride Evolution from Hall‐Heroult Smelting Cells

Wahnsiedler, W.E.; Danchik, R. S.; Backenstose, D. L.; Haupin, W. E.; Colpitts, J. W.

doi:10.1002/9781118647851.ch129

Cited by 3 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…10 Entrained electrolyte also contributes to the particulate fluoride emission; measurements have shown that only 2.5% of the total evolution of fluorides from the electrolytic cell is electrolyte droplets. 11 Since beryllium difluoride (BeF 2 ) has a vapour saturation pressure of 50.2 torr at 950 C, Be may simultaneously with the other fluorides identified vaporise as a fluoride and be a part of the quenched vapours in the electrolytic process. 12 Personal exposure assessments (PEAs) of workers involve measurements of a worker's personal inhalation exposure and are widely accepted and regulated.…”

Section: Environmental Impactmentioning

confidence: 99%

Occupational exposure to beryllium in primary aluminium production

et al. 2012

View full text Add to dashboard Cite

Alumina used in the production of primary aluminium contains Be which partly vaporises from the cryolite bath into the workroom atmosphere. Since Be may be toxic at lower exposure levels than previously thought, the personal exposure to Be among workers in 7 Norwegian primary smelters has been assessed. In total, 480 personal Respicon® virtual impactor full shift air samples have been collected during 2 sampling campaigns and analysed for water soluble Be, Al and Na using inductively coupled plasma optical emission spectrometry. In addition, water soluble F(-) has been measured by ion chromatography. The Be air concentrations in the inhalable, thoracic and respirable aerosol fractions have been calculated. The Be concentrations in the inhalable aerosol fraction vary between the different smelters. The highest GM concentration of Be in the inhalable fraction (122 ng m(-3), n = 30) was measured in the prebake pot room of a smelter using predominantly Jamaican alumina where also the highest individual air concentration of 270 ng m(-3) of Be was identified. The relative distribution of Be in the different aerosol fractions was fairly constant with the mean Be amount for the two sampling campaigns between 44-49% in the thoracic fraction expressed as % of the inhalable amount. Linear regression analysis shows a high correlation between water soluble Be, Al, F and Na describing an average measured chemical bulk composition of the water soluble thoracic fraction as Na(5.7)Al(3.1)F(18). Be is likely to be present as traces in this particulate matter by replacing Al atoms in the condensed fluorides and/or as a major element in a nanoparticle sized fluoride. Thus, the major amount of Be present in the work room atmosphere of Al smelter pot rooms will predominantly be present in combination with substantial amounts of water soluble Al, F and Na.

show abstract

Section: Environmental Impactmentioning

confidence: 99%

Occupational exposure to beryllium in primary aluminium production

et al. 2012

View full text Add to dashboard Cite

show abstract

“…It is formed by reaction with fluorides in the bath or vapour phase according to reactions: 44 Water is available from the humidity in air but also the structural hydroxy groups in the primary alumina. 38,64 In addition, HF may form from the hydrogen content of the anode, where an electrolytic reaction has been proposed: 63…”

Section: Fluoridesmentioning

confidence: 99%

Aluminium Primary Production Off-Gas Composition and Emissions: An Overview

Aarhaug

Ratvik

2019

JOM

View full text Add to dashboard Cite

“…It is commonly accepted that beside the bath chemistry the operational practice has a considerable effect on the gas composition and condensation products in the off gas [1,2]. Large current density increases may only be realized by increasing the heat losses to maintain the heat balance of the cell.…”

Section: Introductionmentioning

confidence: 99%

Particulate Emissions from Electrolysis Cells

Gaertner¹,

Ratvik²,

Aarhaug

2011

Light Metals 2011

View full text Add to dashboard Cite

In the dry cleaning of the exhaust gas from the aluminium cells impurities are accumulated in the finer fractions of secondary alumina from the dry scrubbers. The present work describes new methods for the determination of dust composition, aiming at increasing the understanding of the effect of cell operation on the amount and the composition of dust in the fume. New and advanced analysis methods are used to characterize a broad specter of emissions. An Electrical Low Pressure Impactor is used to sample and analyze the dust from the cells. The equipment enables real-time particle size distribution analysis of 12 particle classes in the range 30 nm-10 µm. The size classified samples are analyzed by means of SEM/EDS and XRD to determine the characteristic chemical composition of the different fractions. Understanding the evolution, evaporation, and condensation of particulates in the cell emissions under different operational conditions may facilitate new standards for environmental friendly and energy efficient high amperage electrolysis cells.

show abstract

Factors Affecting Fluoride Evolution from Hall‐Heroult Smelting Cells

Cited by 3 publications

References 0 publications

Occupational exposure to beryllium in primary aluminium production

Occupational exposure to beryllium in primary aluminium production

Aluminium Primary Production Off-Gas Composition and Emissions: An Overview

Particulate Emissions from Electrolysis Cells

Contact Info

Product

Resources

About