Sodium Bicarbonate: Soda Crystals Exposed to Carbonic Acid in Chambers (the Old Process)

Before the ammonia-soda works, baking soda was made by simply letting carbonic acid gas soak into soda crystals, as Thorpe's Dictionary (1913) describes. The crystals stand in layers on a lath false bottom; the gas comes in below, nine of the crystals' ten molecules of water drain away as mother liquor, carrying the impurities with it, and after 6 to 9 days the crystals have turned into loose, damp bicarbonate in their own shape. It is dried at no more than 45 °C. The picture: our diagram.

مبتدئ

3 weeks

التعليمات

Stack soda crystals on the lath bottom

Put ordinary soda crystals (yellow or inferior ones do as well) in regular layers on a false bottom of laths in a closed chamber (preferably iron), leaving space below for the drainage.

المواد لهذه الخطوة:

صودا الغسيل1 as required

الأدوات المطلوبة:

غرفة تغويز بقاع كاذب من الألواح الخشبية

قفازات مطاطية

Pass in carbonic acid for 6 to 9 days

Lead carbonic acid gas in below the false bottom; it is usually made from calcium carbonate and hydrochloric acid (ours: whiting in a gas generator). The mother liquor drains off through a U-tube in the chamber bottom. The process is finished when this flow stops, generally in 6 to 9 days.

المواد لهذه الخطوة:

كربونات الكالسيوم (الطباشير المطحون)1 as required

حمض الهيدروكلوريك1 as required

الأدوات المطلوبة:

مولّد الغاز

غرفة تغويز بقاع كاذب من الألواح الخشبية

نظارة واقية من رذاذ الكيماويات

قفازات مطاطية

Dry at no more than 45 °C

Open the chamber: the bicarbonate keeps the shape of the crystals but is a loose, very damp powder. Dry it in a stove at no more than 45 °C; this generally takes 8 to 10 days. Ours: a drying oven.

الأدوات المطلوبة: