Method for enhancing solid-liquid separation in conjunction with laterite leaching

摘要

The invention relates to the hydrometallurgical treatment of laterite ores in order to recover valuable metals. More specifically, the invention presented relates to a method for improving precipitation and solid-liquid separation in conjunction with the leaching of laterite ores. According to the method the slurry exiting the leaching of laterite ores is neutralized, after which part of the slurry is routed to solid-liquid separation. Iron is precipitated from the solid-liquid separation overflow by neutralizing the solution and the solution that is formed, which includes jarosite seeds, is routed to an appropriate point in the process to control the precipitation of iron and to enhance the filterability of the solids.

主权项

1. A method for recovering the valuable metals of laterite ore, comprising:
leaching the laterite ore into mineral acid in a leaching stage; and precipitating iron dissolved in the leached laterite ore by means of a suitable neutralizing agent, iron-containing residue thus generated being separated by solid-liquid separation wherein solid-liquid separation is enhanced so that iron-containing solids produced in a separate process stage are fed as a precipitation agent to precipitate the iron as jarosite, wherein the precipitating agent comprises jarosite crystals and gypsum, in an amount of over 90 per cent by weight.