amine additive added to the liquor is from 0 020 to 0 040 gallons of the amine per ton of soda ash produced forty to seventy percent of the total addition must be added to the filtration feed pipeline 6 the production rate of soda ash can be calculated based on the measured soda ash liquor concentration and liquor feed rate entering the evaporator 20 or decahydrate crystallizer 23 bodies less the system losses due to purge centrifuge recycle and dryer losses caused by air flow entrainment and the like the quantity of amine additive added to other liquor sources such as melted decahydrate mine waters recovered waste streams from surface or underground tailings other sodium containing streams and recycle streams is from 0 010 to 0 020 gallons per equivalent soda ash recovered from said streams the calculation accounts for feed concentration feed rate recovery and losses it is preferred that the amine be added to such streams after crystallization from such processes as a decahydrate crystallizer the crystals separated from the weak bittern mother liquor melted and filtered the amine addition point is after i e follows the melting step and is prior to the filter step alternatively the amine addition point may occur prior to a filtration step and followed by monohydrate evaporation decahydrate crystallization or other crystallization step such as production of sodium bicarbonate or sodium sesquicarbonate adherence to the present process sequence results in a modified anhydrous soda ash product with a very substantially.