PROCESSING OF LOW-POTASSIUM SODA-POTASH SOLUTION WITH HIGH CONTENT OF SULPHUR Russian patent published in 2008 - IPC C01D5/00 C01D7/00 

FIELD: chemistry.

SUBSTANCE: method involves preliminary concentration evaporation of the initial soda-potash solution, its subsequent evaporation until saturation of sulphate salts with separation into a deposit of pure mono-hydrate of soda, separation of potassium sulphate of standard quality from the mother solution of the mono-hydrate of soda through its mixing with the reverse mother solution of unhydrous soda and cooling of the mixed solution to 35-40°C. From the mother solution of potassium sulphate the dirty unhydrous soda is separated and is re-crystallised into a pure mono-hydrate soda with dosing during the process, of a calculated quantity of the initial soda-potash solution from the concentration evaporation. Excess sulphur, not provided for in the initial soda-potash solution, with the required quantity of potassium alkali, is obtained from the process in the form of a self contained Burk's salt (Na₂CO₃2Na₂SO4) on the series scheme in two stages, with separation into a deposit on the first stage of glaserite salt (Na₂SO₄3K₂SO₄) from the mother solution of the monohydrate solution soda through its cooling down to 35-40°C, with subsequent re-crystallisation of the obtained glaserite salt into Burk's salt (Na₂CO₃2NaSO₄) specially made for this purpose through a saturated solution the mono-hydrate soda, dosed in the process from calculation of obtaining, after re-crystallisation of the glaserite salt from the mother solution with a molar index of potassium of not more than 17%.

EFFECT: invention allows complex processing of soda-potash solutions.

1 dwg