Removal of heavy metals using magnetic flocs

This paper describes the preparation and use of synthetic magnetite for the removal of heavy metal ions. The synthesis involves adding a solution cont aining ferrous and ferric ions to the heavy metal and using caustic soda to form a magnetic precipitate. The process was investigated in the presence of calcium and nickel ions and it was found that the flee lost its magnetic properties if the concentration of these two divalent ions was too high. T o show that the magnetic flee removed the ions, blank tests were carried ou t with caustic soda alone. The results showed that the magnetic flee was ve ry effective in removing nickel and zinc but was less successful with calci um.