Control of silica scaling during acid leaching of lateritic ore
US4399109A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 1982 |
| Grant date | Aug 16, 1983 |
| Priority date | — |
| Expiry date | Feb 26, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method is provided for inhibiting the formation of silica scale on flash-pot surfaces during the multi-stage flashing of sulfuric acid pressure-leach slurry obtained following the continuous autoclave leaching of nickel lateritic ore at elevated temperature and pressure during which silica is dissolved, wherein the leach slurry is subjected to a high-temperature flash stage such that the slurry at the flash temperature is supersaturated in soluble silica, and wherein the slurry is thereafter subjected to at least one additional flash at an intermediate-temperature flash stage at which silica precipitates and tends to form a scale accompanied by a decrease in said supersaturation. The improvement resides in recycling a substantial portion of the slurry to the intermediate-temperature stage following flashing to the intermediate-temperature flash stage, the portion recycled being sufficient to effect a dilution in silica concentration of the slurry being flashed into the intermediate-temperature flash stage from the high-temperature stage, and continuing the recycling of flashed slurry to the intermediate-temperature flash stage, whereby silica scale formation at the intermediate-t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.