Coprecipitation of silica with aluminum hydroxide

Coagulation With Hydrolyzing Metal Salts: Mechanisms and Water Quality Impacts

“…Early studies demonstrated that phosphate, fluoride, and simple organic acids inhibited or prevented crystallization of aluminum hydroxide coprecipitated with these ligands (Violante and Huang, 1985;Violante and Violante, 1980). Aqueous silica has also been identified as a ligand capable of poisoning the polymerization, precipitation, and crystallization of aluminum hydroxide, presumably through the formation of stable aluminosilicate colloids (Brace and Matijevic, 1977;Exley and Birchall, 1992;Violante and Huang, 1985). Schenk and Weber (1968) found that environmentally relevant concentrations of aqueous silica (0.1 and 1.0 mM) significantly inhibited ferric hydrolysis at pH 3.5.…”

Treatment of mining acidic leachates with indigenous limestone, Zimapan Mexico

“…Co-precipitation of Cd with HFO is thus the most likely removal process of this metal. Removal of SiO 2 may have been occurred by either chamosite formation or by co-precipitation with HFO [27] or with Al hydroxides [31]; nevertheless, the calculated SI suggests the formation of several silicon phases like kaolinite.…”

Significance of Pourbaix Diagrams to Study the Corrosion Behaviour of Hardfacing Alloys Based on Chromium Carbides at 298 K (25 °C)

“…Although carbides are selected on the basis of only their hardness [1], their corrosion properties are often not considered. In spite of this, hardfacing alloys are used in the alumina industry, the pH of the mining solution is about 14 [3,4] and in sugarcane crushing the pH is about 3 [5]. Other than this, these alloys are also used in cement, oil and gas drilling, dredging, etc., industries which all operate under corrosive environments.…”