APROVEITAMENTO DO REJEITO DE MINÉRIO DE FERRO: TENDÊNCIA E OTIMIZAÇÃO DE PROCESSO ATRAVÉS DE CONCENTRAÇÃO MAGNÉTICA

Abstract

Almost all flow models for martian gullies to date have assumed liquids that exhibit viscosities on the order of 1 cP (10(exp -3) Pa.$) such as pure water [1,2] and liquid carbon dioxide [3]. Alternatively, salt solutions have been suggested based on thermodynamic and kinetic arguments as a way to stabilize liquid water in present day martian conditions [4,5]. We have recently proposed that concentrated aqueous solutions of ferric sulfate Fe2(SO4)(sub 3) might be a liquid under martian conditions because it has amongst the lowest eutectic temperature (205 K) of common ionic materials [6]. This paper reports on experimental measurements of the viscosity of ferric sulfate solutions as a function of temperature and concentration [7]. We then use this information in a numerical flow model of a standard gully as a bridge between the composition and temperature of the brine and the fluid dynamics, to identify geomorphological characteristics that might be observed on Mars [8,9]. Specifically, in this study we estimate the flow velocity and the drag forces on boulders within the gullies for these highly viscous fluids.