Development and Investigation of an Apparatus for Determining the Wetting of Quartz Sand

Abstract

An apparatus for determining the wettability of quartz sand was developed. It was shown that as the temperature increases, the surface wettability of the minerals present in the glass quartz sand increases owing to a reduction of the slippage of the liquid along the solid surface and, in consequence, the aggregative stability of their suspensions increases.Aqueous disperse systems of hydrophylic minerals (quartz, iron and aluminum oxides, and others) are characterized by a high free interphase energy F, which always tends to decrease, which is the reason for aggregation of particles accompanied by a reduction of this energy (F ® min). As particles undergo aggregation the primary structural-mechanical properties of disperse systems change (the systems lose flowability and easy mobility, their viscosity increases, and the modulus of elasticity and ultimate strength come into play), which degrades quality in the production of modern building articles [1]. The factors determining the properties of a disperse system upon loss of aggregative stability are the force and energy of bonding (interaction) between particles in contact and the number of particles per unit volume.A special apparatus was developed to investigate the aggregative stability of disperse systems by means of sedimentation-volumetry (Fig. 1). In this setup the sediment forms on a porous barrier upon kinetic breakdown of the suspension with volumetric rate v and filtration outflow of the disperse medium.The apparatus looks like an hourglass, the only difference being that the reservoirs 1 and 2 are filled with water and connected by a long graduated tube 3 with a small diameter instead of a short tube. The analogy with an hourglass can be extended: when measuring time an hourglass is in- Fig. 1. Apparatus for sedimentation volumetric measurements: 1, 2 ) accumulating reservoirs; 3 ) small-diameter tube; 4 ) porous glass plate; 5 ) stopcock; 6 ) thermostating jacket; 7 ) stopper; 8 ) measuring scale; 9 ) water feed from thermostat.