Joint International Conference on Long-term Experiments ...

The classical calco-carbonic purification of the diffusion juice consists in the juice’
treatment with lime milk and the subsequent precipitation of the excess (surfeit) of
Ca(OH)2. The resulted mud’ separation raises some special problems. That is the reason
for which, in practice, there have been introduced some purification methods to which
some compromises are being made between the purification effect and the separation
capacity, through decantation or through mud filtering.
RESULTS AND DISCUSSIONS
The technological role of the diffusion juice’ calco-carbonic purification in the process
crystal sugar obtaining consists in the elimination of a part of the diffusion juice’ nonsugar
substance employing some operations specific to each non-sugar groups and
which would provide ,at the given momentum, some optimal conditions for the
destruction and elimination of a certain sugar type. Punctually, the role of the calcocarbonic
purification consists in:
• Neutralizing the acidity of the diffusion juice and precipitating the calcium salts;
• Precipitating and separating diffusion juice’ colloids;
• Decompounding the reducing substances (agents) and the amides and obtaining the
heat-proof (thermo stable) juices;
• Non-sugar absorbing and adsorbing on the calcium carbonate (limestone)
• Mud decanting (separating) out of the purified juice;
• Sweetening the mud;
• Thin juice decalcifying and preventing the concentrating station’ peeling through
vaporization.
In order to obtain the diffusion juice purification one employ calcium oxide under the
lime milk shape and carbonadoing gas containing carbon dioxide.
In the chart 3 there are represented the characteristics of the lime milk used for
purification in sugar factories.
Table 3. The characteristics of the lime milk used for
calco-carbonic purification in sugar factories
Concentration in dry Specific CaO content Ca(OH)2 content
substance mass
ºBe ºBx g/cm 3 g/l g/100g g/l g/100g
1,49 2,69 1,0084 9 0,98 13,1 1,30
4,69 8,39 1,0314 39 3,87 52,7 5,12
7,59 13,69 1,0534 69 6,64 92,4 8,78
10,34 18,69 1,0749 99 9,29 132,0 12,28
15,54 28,19 1,1184 159 14,29 211,3 18,89
20,34 37,09 1,1614 219 18,93 290,6 25,02
25,49 46,79 1,2124 289 23,91 383,1 31,60
For an accurate evaluation of the function of the diffusion juice purification’ station
from a sugar factory it is necessary to be aware of the exact amount of carbonadoing
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