Nitric acid activation of bentonite has been studied with the aim of harmonizing bleaching earth and ammonium nitrate fertilizer production, where the latter is obtained from waste acid via neutralization with ammonia. In this paper, a mathematical model is described for composition measurement of the waste acid formed during the activation of the bentonite. On the basis of the results obtained from the model, the amount of concentrated nitric acid necessary for refreshing the recycled acidic solution can easily be estimated. The amounts of the products formed during ammoniacal neutralization, such as ammonium nitrate, hydroxides of hydrolizable metals, and nitrates of nonhydrolizable metals, as well as the amount of activated bentonite, can also be calculated. It is established that, with an increase in the recycling number, the activation process becomes more economical via decreasing energy and material requirements.
ASJC Scopus subject areas
- Chemical Engineering(all)
- Industrial and Manufacturing Engineering