The transformations suffered by bentonite and coal waste are subjected
to an alkaline treatment with the purpose of: a) taking advantage of
some unknown characteristics of the coal waste; b) obtaining products
with more cationic retention capacity, in particular ammonia retention
, that we are studying for aquiculture; c) comparing coal waste result
s with the results of a conventional bentonite. In this study, remarka
ble increases in some of the obtained products with regard to the init
ial materials are achieved.