Description and Discussion of Some Extraction Methods (French) Available to Purchase

S). POUT caractériser le fonctionnement d', une êtape dans laquelle les piiases n'atteignent pus l'eyuitlbrz, un inliuûuisit le facieur rendemenl CU l'etape uoni lu dediiiiliun s'ecurle de c ~ 'ii ~ 11)I u usuye couralkl jusqu'd presenl, el poss ède sur celle-ci de.$ aoanlnyes de piiircipe. I l indique aussi comment on peut faire entrer en ligne de comple l'enlrainement récri- pruy'ue des pliuaes, lout en démontrant qu 'il es1 inexact de décrire cei elset au du IiLOy ~ik IGIL. clefr~enl de l'elupe, covime cela se fail d'nabilude. S UhlM AR Y The extraction processes are divided into elementary processes which take place in a U)I,. slnyle stage and in, which the two phases tend to attain a state o/ eqUilabTilbm, and complez U prucesses in Which the latter is not the case. Complex processes may be conceived to be 1 1, buiit up of elementary processes. l'lie importance is pointed out of clearly distinguishing the various co, nceplions concerned in lhis building 'up and o& designating them by suitable names. 1 arious cuinpiex processes are compared, ciz. counter-current processes I) i n ideal slayes, i?) LB slayes in ~cclicch lhe equilibrium is not attained, 3) in stages in which the P ~USGS pur.11~ eirirum euch other und 4) gradually acting countercur ~ent processes (e.g. those talcziig place it1 Irlled columns). b'or clia~acteriziny the elficacy of a stage in which the phases do not attain the slate u / c~yciilibriurn a factur iermed slage-efficiency was introd?iced, the definition 01 which diElers U I> drum tital used hitkerlo and possessing certain fundamental advantages. ï'he manner in, which the mutual entrainment of the phases can be accounled for was also indicated and it was proved to be inoorrect to express this effect by means 01 the stage effi. ciency, as is usually done. AUSZUG Die Extraktiunsverlahren Wurden ei