亜硫酸ガス吹き込みによるマンガンノジュールの還元浸出

Abstract

Pacific Ocean Manganese nodules were leached in a water or in an ammoniacal solution using sulfur dioxide as a reductant, and studies were made of the effects of various factors on the percent extraction of nickel, cobalt, copper, manganese and iron.When the ore was leached in a water using sulfur dioxide as a reductant, almost all metals were extracted completely in a short time at a room temperature. Extraction of iron was suppressed as elevating the leaching temperature, while selective extraction of nickel, cobalt and copper was not attained as far as water was used as a solvent.The selective extraction of nickel, cobalt and copper from manganese nodules was attained by using ammoniacal solution as a solvent and using sulfur dioxide as a reductant. The leaching residue was mainly composed of manganese ammonium sulfite hydroxide in an ammonia solution, while manganese carbonate was detected at the ammonium carbonate solution leaching. The extraction percentages of metallic components under optimum conditions were 99% for copper, 98% for nickel, 95% for cobalt, 3% for manganese and 1% for iron, respectively.