Process for making sodium bicarbonate from Nahcolite-rich solutions
US5588713A · kind A · utility
Inventor
Key dates
| Filing date | Dec 20, 1995 |
| Grant date | Dec 31, 1996 |
| Priority date | — |
| Expiry date | Dec 20, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/129
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for making sodium bicarbonate from Nahcolite-rich solutions utilizes solubility suppression with addition of salt. Hot water pumped into a Nahcolite-rich formation, which may contain salt (NaCl) and other impurities in excess of 6% by weight, dissolves the Nahcolite (NaHCO.sub.3) and salt. The dissolved Nahcolite is brought to the surface as a pregnant brine liquor containing Nahcolite, salt, and other impurities, which is then de-gassed under pressure. The pregnant liquor is then mixed with a salt slurry and its temperature reduced to saturate it with salt and force precipitation of Nahcolite out of the pregnant liquor. Carbon dioxide (CO.sub.2) is injected while mixing the pregnant liquor with the salt to facilitate precipitation and conversion of any sodium carbonate (Na.sub.2 C.sub.3) present into sodium bicarbonate (NaHCO.sub.3). The sodium bicarbonate (NaHCO.sub.3) is dewatered and filtered to form a sodium bicarbonate (NaHCO.sub.3) filter cake, which is washed with fresh cold water to remove salt (NaCl), sodium carbonate (Na.sub.2 CO.sub.3), and other impurities as a salt-rich brine filtrate, and the filter cake is dried to produce a high grade of natural sodium bi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.