The mother-liquor now falls to a specific gravity of 1.3082 to 1.2965, and yields a very mixed deposit of magnesium bromide and chloride, potassium chloride and magnesium sulphate, with the double magnesium and potassium sulphate, corresponding to the kainite of Stassfurt.
1 A " eutectic " is the last-freezing part of an alloy, and corresponds to what the mother-liquor of a saline solution would become if such a solution, after the excess of saline matter had been crystallized out, were finally completely frozen.
There the reaction mentioned above takes place, and Owing to the concentration of the liquid the sodium bicarbonate formed is to a great extent precipitated in the shape of small crystals, forming with the mother-liquor a thin magma.
There is also deposited a double magnesium and potassium chloride, similar to the carnallite of Stassfurt, and finally the mother-liquor, which has now again risen to specific gravity 1.3374, contains only pure magnesium chloride.
After twenty-four hours about one-half of the silver has separated out in crystals; from the mother-liquor the rest comes down promptly on application pf a water-bath heat.
Thus also the crystals already formed come in contact with fresh mother-liquor, and so go on adding to their size.
The recovery of the ammonia from the mother-liquor coming from the vacuum filters and various washing liquors.
Here a separation takes place between the crystals of sodium bicarbonate and the mother-liquor.
It is the mother-liquor or " bittern " frozen.
The corresponding potash compounds are not manufactured in the United Kingdom, but exclusively in Germany (from potassium chloride and from the mother-liquor of the strontia process in the manufacture of beetroot sugar) and in France (from vinasse).