A process for the controlled leaching of natural manganese dioxide by using hydrochloric acid

摘要

The present invention relates to a new process for extracting and recovering natural manganese dioxide (NMD) deleterious matter by using a hydrochloric acid solution as leaching agent, which process is carried out in a sequence of equipment the control devices of which are calibrated in such a way that the mixture contained in the leaching machine must have a pulp density of 10%-40% weight, a hydrochloric acid concentration between 9% and 25% weight, a temperature between 80.degree.C and 95.degree.C, and a leaching time between 10 and 60 minutes resulting from the interaction of certain values, these variables being limited wherein the amount of deleterious matter and MnO2 to be extracted and recovered according to expected results shall be defined.