Rheological behaviour and heat effects during the formation and phase transformation of silver oxide gels obtained by precipitation

Freshly precipitated silver oxide gel obtained from the addition of alkali in silver nitrate solution of high concentrations is suspected to have quite non-Newtonian properties. The knowledge of its rheological behaviour can be helpful when choosing the mixing device for precipitation reactors. In this paper, the rheological behaviour of the concentrated suspension is investigated and the choice of appropriate mixer is discussed. the precipitation, the temperature evolution exhibits two steps: the exothermic reaction is supposedly responsible for the first step, the second one seems to occur exactly when the gel is breaking down. Hence, a calorimetric study is also carried out in order to investigate this phenomenon linked to the rheological behaviour.