| 摘要 |
<p>PURPOSE:To improve the reaction efficiency and to enable the operation under the ordinary temp. and the atmospheric pressure by specifying the neutralizing condition of hydrochloric acid leaching liquid and using fine iron powder to a substituting precipitating reaction of nickel. CONSTITUTION:Garnierite is pulverized and leached with the hydrochloric acid to separate the leached residue containing silica as the main component. The neutralizing agent of MgO, etc., is slowly added into the leaching liquid and the pH is made to 0.1-3.5 to neutralize the free hydrochloric acid and the iron precipitation is produced. The fine iron powder is added in this leaching liquid and kept to 40-100 deg.C and the substituted precipitation of Ni in the leaching liquid is executed under the atmospheric pressure and the precipitated metallic nickel is separated. By air-oxidizing or neutralizing the solution after recovering the nickel, the pH is made to 3.5-7.5 and the iron is precipitated and filtered and separated, and magnesium chloride-containing water solution is dried and roasted to recover the hydrochloric acid and MgO.</p> |
