The equilibrium states of the reversible alkali-calcium ion exchange reaction Was Studied with strongly acidic ion exchange resins, based on systematic measurements to determine the apparent equilibrium constant K defined with ion fractions in the resin and Solution. This constant has a decisive role in the quantity of alkali required for regeneration of the Ca form of the resin. Important phenomena, Such as precipitation reactions during ion exchange Lire also reflected in the value of the constant. The equilibrium Of the ion exchange was examined as,I function Of the dry Substance content, purity anti ion concentrations. The results show that the most important factor influencing the equilibrium constant in sugar factory solutions is the purity because K increased more than all order as purity decreased from 90%, (thick juice) to 60% (molasses). A further enormous increase in K was found in concentrated sugar-free solution (vinasse). The next important parameters are the dry Substance content and ion-concentration of the model and factory solutions. It is concluded that the favorable change of K from the regeneration point of view is attributed to the nonsugars, especially to N-containing organic compounds of sugar factory juices decreasing the activity Of Ca ion to the resin, Supported by activity measurement using I Ca-selective electrode. The beneficial shift of the equilibrium constant is exploited in the Gryllus and ResinDioN (RDN) regeneration processes. In alkaline Solutions used in the New Regenerant Solution (NRS) process the equilibrium constant shifts also favorably, but to a less extent. The results also highlight some of the advantages and disadvantages of the different existing regeneration methods discussed finally in the paper.
