Warm raw juice is drawn into the carbonatation tanks and treated with
about 10 per cent milk of lime--about like ordinary whitewash. This
lime throws out impurities, sterilizes the juice and removes coloring
matter. Carbonic acid gas from the lime kiln is forced through the
lime juice in the tank, throwing out the excess of lime, converting it
into a carbonate of lime or chalk. Tests are taken here by the station
operator to show when the process is finished.]
[Illustration: FILTER PRESSES.
From the carbonatation tanks the juice is pumped or forced through
filter presses consisting of iron frames so covered with cloth that the
juice passes through the cloth as a clear liquid, leaving the lime and
impurities precipitated by it, in the frame, in the form of a cake.
This cake, after washing, is dropped from the presses and conveyed out
of the factory. It contains from one to two per cent of its weight
in sugar, which constitutes one of the large losses of the process.
It also contains organic matter, phosphate and potash, besides the
carbonate of lime, which makes it an excellent fertilizer, all of which
is used in Europe on the farm, but so far to too small an extent in
America.]
[Illustration: EVAPORATING THE WATER FROM THE SUGAR