Continuous separation of Fe–Al–Zn dross phase from hot dip galvanised melt using alternating magnetic field

Abstract

Experiments to continuously separate Fe-Al-Zn dross phase from hot dip galvanising zinc melt were conducted on a laboratory scale apparatus by using high frequency alternating magnetic field. Effects of processing time (t) on separation efficiency were investigated. The experimental results show that using the electromagnetic repulsive force resulting from the electrical conductivity difference between zinc melt and Fe-Al-Zn dross phase, the deleterious zinc dross particles causing surface defects of galvanising steel sheets can be continuously separated from the zinc bath under alternating magnetic field, and the separation efficiency increases with the increase in processing time. When the magnetic frequency is 17?5 kHz, the effective magnetic flux intensity is 0?1 T, the cross-section of the ceramic square pipe is 10610 mm, and the processing time is 0?6-2?5 s, the separation efficiency of zinc dross varies from 43?76 to 85?71%, and the experimental results are in reasonable agreement with the theoretical results.

The Evaluation on Corrosion Resistance and Dross Formation of Zn–23 wt % Al–0.3 wt % Si–x wt % Mg Alloy

“…The dissolution rate of iron will increase from 0.8 to 1.8 g/(m 2 •s) as the content of Al rises from 20 to 30 wt % and the dissolution rate of steel is 2.3 g/(m 2 •s) when the content of Al rises to 55 wt % [5]. Fe 2 Al 5 , τ 5 (Al 8 Fe 2 Si), and τ 6 (Al 5 FeSi) phases will be generated and form in the top, floating, and bottom dross in the high Al content condition, once the iron content exceeds its solubility in the zinc bath [6]. The floating dross in the molten bath mainly includes oxide such as zinc oxide and alumina.…”

Recovery of Zinc from Zn–Al–Fe Melt by Super-gravity Separation

“…3(b)) due to the lower density of the dross particles than the alloy matrix. 12) As shown in Fig. 3(c), after super-gravity separation, the dross particles were intercepted by the filter and gathered in the residue.…”

Separation of Non-metallic Inclusions from Molten Steel Using High Frequency Electromagnetic Fields

“…[24] Studies to remove inclusions from molten aluminum, copper, zinc, and silicon using AC magnetic field have been well reported and attained satisfying results, such as the studies reported by El-kaddah and Taniguchi, [7,8,[25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42] as shown in Table II. However, there were very few studies on the purification of steel using high frequency EM separation. The possible reason for this lack is that the EM purification experiment for steel is difficult due to its high melting temperature compared to that of aluminum and copper.…”