<p>Consideration has been given to a mathematical model of an irreversible isothermal process of extraction of a redistributed component from a solution. An expression has been obtained for the minimum entropy production at an assigned coefficient of mass transfer and efficiency. It is shown that the conditions of minimum dissipation correspond to the lowest mass transfer coefficient at a fixed efficiency or to the highest efficiency at a fixed mass transfer coefficient. The optimum ratio between the flow rates of extractant and solution has been found.</p>