Study on Extrusion Process of Hard Shale Mud

Abstract

A crushed hard shale mixed with flocculating or dispersing aqueous solutions and ram-extruded, obeyed the expression P=Poe-K(φ-φo), where P was the pressure which initiated extrusion, φ was the volume fraction of liquid, and Po and k were constants. For size fractions having five different particle sizes, plot of logP against φ converged on common points, coordinates logPo and φo, irrespective of the flocculation or dispersion of the system. The slopes -K were less for flocculated than for dispersed particles. At φ=φo each particles contact with one another directly and the effect of the liquid at the contact point can be ignored, because φo can be considered that the void fraction at most closely packed. Under the above consideration, the interaction force at the contact point of particles fp can be calculated using the value of Po. The values of fp obtained from the Po agreed with the adhesion force of venous inorganic particles.