Two-step alkaline thorium dioxide precipitation A low waste method for highly sinterable ThO2

We precipitated thorium in a two-step process with ammonia and carbonates. In contrast to single step or carbonate precipitation, the precipitates >99.9% of Th removes >99.5% Ra alongside. Filterability is strongly affected by pH variations step, under well-controlled conditions, ThO2 filters quickly calcines crystalline at low temperatures. As-precipitated contains significant quantities adsorbed H2O CO2, which are removed during calcination. The calcination temperature greatly affects green density produced pellets, but for all temperatures investigated, sintered densities excess 96% grain sizes within range applied nuclear fuels 10–16 ?m.