Laboratory studies have been conducted for dissolution of potassium from gl
auconitic sandstone in diluted hydrochloric acid, nitric acid and sulphuric
acid at different temperatures. The dissolution of potassium was analysed
with different kinetic models. The dissolution of potassium follows a mixed
control model embodying chemical control model at the initial stages of di
ssolution and diffusion control model at the later stages of dissolution fo
r all the three lixiviants. The activation energy for dissolution of potass
ium in hydrochloric acid varies from 79.03 to 99.41 kJ/mol, whereas in nitr
ic acid and sulphuric acid, it varies from 56.93 to 95.18 and 37.43 to 56.2
4 kJ/mol, respectively. (C) 2000 Elsevier Science B.V. All rights reserved.