FREMGANGSMAATE VED ADSKILLELSE AV KROM FRA PARTIKKELFORMIGE, LATERITTISKE MALMER

摘要

Extraction of chromium from iron-contg. lateritic ores, leaving a residue suitable for recovery of iron, is improved in that the ore is very finely comminuted to produce a fine fraction form which chromium can be easily extracted with an acid; preparing an aq. slurry contg. 0.1-0.5 pt.wt. of H2SO4 per pt. wt. of the ore (pref. the slurry contains more than 20% of solids); leaching the ore at an elevated temp. (pref. 200-300 degrees C) under an elevated press. (pref. 29-71 kg/cm2); sepg. the lye and opt. washing the undissolved residue. Nickel and cobalt may be extracted along with chromium and then selectively sepd. from the lye. The sepn. of Cr from the ore is nearly complete; other metals, esp. Ni, are also removed, so that the residue is suitable for recovery of iron that can be used in steel mfr. The economy of the process is good.