Waste to Wealth Strategy: Preparation and Properties of Lightweight Al2O3-SiO2-Rich Castables Using Aluminum Dross Waste

Abstract

Aluminum dross is a well-known industrial waste generated in the aluminium industry, and its recycling and reuse is still a worldwide issue. Herein, aluminum dross waste (ADW) was recycled to progressively replace the aggregate fraction of clay at 70, 75, 80, 85, and 90 wt% for the fabrication of Al2O3-SiO2-rich porous castable refractories. Their physical properties and mechanical behavior were assessed by the measurement of linear shrinkage rate, bulk density, apparent porosity, cold crushing strength, and thermal conductivity. The microstructure and phase evolutions were analyzed via scanning electron microscopy (SEM) and X-ray diffraction (XRD). The incorporation of 85 wt% of ADW allowed the development of a waste-containing conventional refractory castable with improved properties as compared to those of the other samples. The sustainable refractory castable exhibited decent thermal conductivity and physical and mechanical characteristics, and is suitable for application as reheating furnace lining. It is a “green” practice to partially replace the traditional raw materials with industrial waste in the manufacture of conventional refractory castables and provides environmental and economic benefits.

Preparation of Self-Coating Al2O3 Bonded SiAlON Porous Ceramics Using Aluminum Dross and Silicon Solid Waste under Ambient Air Atmosphere

“…Different from the concept of separation and purification, some researchers have utilized aluminum dross directly to prepare related refractories. For example, Su et al [ 25 ] synthesized Al 2 O 3 -SiO 2 -rich castables for reheating furnaces through progressive replacement of clay by aluminum dross. Zhang et al [ 26 ] reutilized secondary aluminum dross for preparation of MgAl 2 O 4 , and studied the effect of rare earth oxides on the densification behavior of MgAl 2 O 4 .…”

Effect of Silicon Source (Fly Ash, Silica Dust, Gangue) on the Preparation of Porous Mullite Ceramics from Aluminum Dross

“…AlN in AD will hydrolyze with water, even at room temperature, producing NH 3 and polluting the environment, and the accumulation of AD will cause the leaching of salts (KCl, NaCl, NaF, et al) and gradually destroy the soil environment [ 6 , 7 , 8 ]. In our previous works [ 9 , 10 ], AD was treated using a hydrometallurgy process, and the AlN and soluble salts in AD were removed. The main component of the AD was rich in alumina, which is a renewable resource for the preparation of mullite materials.…”

Co‐utilization of secondary aluminum dross and ferronickel slag for preparation of cordierite–mullite insulating ceramic

“…An open-pore structure will be formed when the gas escapes from the ceramic, whereas gases confined inside will form closed pores. 13,14 After pyrometallurgical detoxification, the main mineral phase of SAD usually consists of Al 2 O 3 and spine (MgAl 2 O 4 ), which can be converted to cordierite (Mg 2 Al 4 Si 5 O 18 ) with the treatment of high temperature. Cordierite ceramic is noted for its low thermal expansion coefficient, good thermal shock resistance, and low thermal conductivity, which makes it suitable for use as a phase for thermal insulating materials.…”

“…Moreover, a special component of SAD, AlN, can be oxidized and transformed into Al 2 O 3 and gas N 2 at high temperature. An open‐pore structure will be formed when the gas escapes from the ceramic, whereas gases confined inside will form closed pores 13,14 . After pyrometallurgical detoxification, the main mineral phase of SAD usually consists of Al 2 O 3 and spine (MgAl 2 O 4 ), which can be converted to cordierite (Mg 2 Al 4 Si 5 O 18 ) with the treatment of high temperature.…”