CONTROL OF SILICA SCALING DURING ACID LEACHING OF LATERITIC ORE

摘要

A method of control of silica scaling during acid leaching of lateritic ore. …In the recovery of nickel from nickeliferous oxide ores by acid leaching at elevated temperature and pressure silica, dissolved in the leach slurry, gives silica scales on flash-pot surfaces during the multi-stage flashing of the slurries from the pressure leach circuit. This method greatly inhibits silica scales formation at an intermediate-temperature flash stage by recycling a portion of the slurry to this stage, in sufficient amount to effect a dilution in soluble silica concentrations and decrease the supersaturation of the slurry flashed from a higher temperature fed to the intermediate temperature no flash stage and continuing this process.