Better analysis of pulping liquors aids operation at Cariboo pulp mill

Liquor analysis is at the heart of the pulping process. White liquor effective alkali measurement is needed for proper rationing of alkali to wood, while black liquor analysis is the key to kappa number control and the optimization of the alkali charge. Proper control of the recausticizing plant requires both green and white liquor analysis, including carbonate measurement. Unfortunately, all these analyses are difficult to perform due to the high pH, elevated temperatures and impurities encountered in the digesting and recausticizing processes. Cariboo pulp mill's use of a new technology known as Fourier transform infrared spectrophotometry to achieve accurate online liquor measurements is discussed.