The present invention refers to a mixing process, for the valorization of used cooking oils by means of a device with household appliance characteristics. The mixing process takes place in a particularly efficient way by means of the supply of a given load (A) of used cooking oils and of a corresponding load (B) of a solidifying composition to a mixing device, whereby certain previously defined amounts of thermal energy are supplied, notably an initial amount until reaching a given temperature level, and an additional amount during a given mixing period. The present invention further refers to a mixing device for the mixing process that presents substantially airtight conditions and eventually, thermal and mechanical energy supply means, as well as monitoring and control means specific of the execution of the mixing process.
