Patent ID: 8529658

Claim:
A ferronickel mass, comprising: an Ni/Fe-containing sludge having a Ni content of at least 10% by weight and manufactured by removing SO 4 by adding an SO 4 neutralizing agent to an Fe/Ni/SO 4 -containing liquid waste in which a value of [Fe(+3) ion concentration]/[Ni ion concentration+Fe(+2) ion concentration] is 1 or less, so that pH of the Fe/Ni/SO 4 -containing liquid waste is maintained to a pH level of 0.5 to 4.5, precipitating Fe and Ni in the form of hydroxide [(Ni,Fe)(OH) 2 ] by adding NaOH to the SO 4 -free solution, washing the precipitate with water, and drying the washed precipitate; and 10 to 20 parts by weight of a binder and 20 parts by weight or less of a reducing agent on the basis of 100 parts by weight of the dry sludge; wherein the ferronickel mass includes at least 8% by weight of Ni.