Stabilization of copper sludge by high-temperature CuFe2O4 synthesis process

Stabilization and phase transformation of CuFe2O4 sintered from simulated copper-laden sludge

“…1. The DSC curve of precursor sample shows endothermic peaks around 790-920 and 1015-1030 • C, and exothermic peak around 920-1015 • C. The first endothermic peak at 790-920 • C may correspond to the solid-state interaction between CuO and Fe 2 O 3 and formation of Cu-Fe-O compound [5,17,18]. Reaction at the temperature above 800 • C can be written as:…”

“…Stabilization of heavy metal sludge by thermal treatment has the potential for converting hazardous metal sludge into mineral phase and reusable product, such as spinel ceramics [5][6][7][8]. Spinel provides advantages of no permeability for liquid and gas, low thermal conductibility, high chemical resistibility, and its Mohs Hardness is equal to 8 [9].…”

“…The formation of spinel materials by thermal process from the parent oxides was extensively studied [5][6][7][8]14,15]. Because of the similar precursors existed in heavy metal sludge, stabilizing heavy metal via thermal treatment has the potential to convert hazardous metal-laden sludge from the waste stream into reusable spinel products.…”

“…Copper sludge was found to react with alumina at high temperature, and the strategy of transforming copper-laden sludge with aluminum-rich precursors into copper aluminate spinel (CuAl 2 O 4 ) shows potential of stabilizing [14][15][16]. Stabilization of copper sludge by high temperature CuFe 2 O 4 ferritization process from 600 to 1000 • C was also conducted successfully [5]. Nevertheless, the phase transformation and stabilization efficiency at the temperature higher than 1000 • C is still needed to discuss.…”

Stabilization of copper-contaminated sludge using the microwave sintering

“…Hence, methods to transform the stabilized sludge into block form are very important. High-temperature treatment processes have been used for powdered waste such as ash and sludge in numerous investigations [6][7][8][9][10][11][12][13][14], and all kinds of products like aggregate, glass ceramics, and adsorbents for heavy metals have been yielded. On the other side, using a microwave sintering for the formation of alloys, ceramics, and various materials is popular because the required temperature and time of formation by this method are less than those required by traditional sintering [15][16][17].…”