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Magnesium oxide for improved heavy metals removal.
Min Eng 1984 Feb; 36(2):171-173
To improve technology for treating process water, U.S. Bureau of Mines research has shown that magnesium oxide (MgO) has many advantages over lime or caustic soda for precipitating heavy metals. Sludge produced by MgO occupies only 0.2 to 0.3 times as much volume as the precipitate made using a soluble base. While a settled, lime-formed precipitate is easily resuspended, the MgO-metal hydroxide sludge becomes cemented together on standing. Settling of the metal hydroxides from a dilute suspension is more complete than precipitates formed with other bases. Virtually any metal that can be precipitated by raising the ph can be treated using MgO. Because of the greater cost of MgO compared with lime, large-scale practice of this technology will probably be limited to water containing 50 mg/l or less of dissolved metals. While the MgO process is technically suitable for widespread application, the extent to which it is adopted will probably be determined by a trade-off between the greater cost of MgO compared with lime and the superior properties of the precipitates and their corresponding ultimate disposal costs.
Magnesium-compounds; Heavy-metals; Waste-treatment; Waste-disposal
OP; Journal Article
Issue of Publication
Page last reviewed: May 5, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division