V izuchenii i opisanii perenosa veshchestv cherez podvizhnye granitsy sistem zhidkost'-zhidkost' dominiruet traditsionnyy podkhod, pri kotorom v kachestve dvizhushchey sily ispol'zuyut raznost' kontsentratsiy, svoystva faz schitayutsya neizmennymi vplot' do mezhfaznoy granitsy, a sama granitsa - ne imeyushchey tolshchiny. V to zhe vremya, ekstraktsiya neorganicheskikh veshchestv, pochti vsegda soprovozhdaetsya khimicheskimi reaktsiyami i takimi yavleniyami, kak gidrodinamicheskaya neustoychivost', samoproizvol'noe dispergirovanie, obrazovanie dispersnykh mezhfaznykh sloev, adsorbtsiya dispersnykh chastits, ikh koagulyatsiya i vozniknovenie strukturirovannykh mezhfaznykh plenok. Dannye protsessy formiruyut novuyu dinamicheskuyu mezhfaznuyu oblast', novye usloviya protekaniya reaktsiy i perenosa massy v ney. Issledovateli poka ogranichivayutsya lish' konstatatsiey fakta o nalichii fraktal'noy razmernosti u mezhfaznoy oblasti. Popytki opisaniya protsessov, proiskhodyashchikh v ney, natalkivayutsya na matematicheskie trudnosti. Odnako, perenos massy vo fraktal'nykh sredakh mozhno opisyvat' s pomoshch'yu differentsial'nykh uravneniy, soderzhashchikh drobnye proizvodnye. Predlagaemyy metod chislennogo resheniya takikh uravneniy pozvolil vpervye izvlech' informatsiyu o mezhfaznykh yavleniyakh.