Continuous countercurrent process for the transition of substances between a liquid and a solid phase

Claim 1

A CONTINUOUS PROCESS FOR EFFECTING A MATERIAL EXCHANGE BETWEEN A COMMINUTED SOLID PHASE CONTAINING DUST PARTICLES AND A LIQUID PHASE COMPRISING (A) EQUALLY DISTRIBUTING THE LIQUID PHASE OVER THE ENTIRE CROSS-SECTION OF AN ELONGATED VERTICAL CONTACT ZONE, THE HORIZONTAL CROSSSECTION OF SAID ELONGATED VERTICAL CONTACT ZONE BEING CONSTANT OVER THE ENTIRE LENGTH, (B) CONTACTING THE PHASES IN COUNTER-CURRENT FLOW IN SAID CONTACT ZONE, (C) CONDUCTING THE LIQUID PHASE ASCENDINGLY AND LONGITUDINALLY THROUGH THE CONTACT ZONE AT A VELOCITY WHICH IS CONSTANT THROUGHOUT ANY PLANE TRANSVERSE TO THE DIRECTION OF MOVEMENT WITHIN THE CONTACT ZONE, SAID VELOCITY BEING SMALL ENOUGH TO ALLOW THE DUST PARTICLES OF THE SOLID PHASE TO MOVE BY THE ACTION OF GRAVITY EXCLUSIVELY IN OPPOSITE DIRECTION TO THE LIQUID CURRENT, (D) MAINTAINING WITHIN THE CONTACT ZONE WITHIN ANY GIVEN PLANE TRANSVERSE TO THE DIRECTION OF MOVEMENT WITHIN THE CONTACT ZONE A UNIFORM DISTRIBUTION OF LIQUID AND SOLID PHASE THROUGHOUT SAID GIVEN PLANE, (E) MAINTAINING IN THE CONTACT ZONE AN INCREASING CONCENTRATION OF THE SOLID PARTICLES IN THE DIRECTION OF THEIR MOVEMENT BY WITHHOLDING THE REMOVAL OF THE SOLID PHASE FROM THE CONTACT ZONE AT THE BEGINNING OF THE PROCESS AND, (F) REMOVING EACH PHASE FROM THE CONTACT ZONE.