Study of Heavy Fractions Distribution in Fluctuating Loose Environment

Abstract

One of the effective methods of separation of heavy grains in the loose environment, for example, of gold grains, is jigging. In the known works on modeling of process of jigging the theory of a Brownian particle is used where the equation like Fokker-Planck’s one is solved. Most of the works do not consider interaction of particles of a useful fraction among themselves. This work is devoted to determination of parameters accounting the interaction of these particles. These parameters received by mathematical modeling of the process are determined experimentally. We considered a magnetic in natural sand. This material (heavy fraction) has bigger density than sand (about 1.2 times). The heavy fraction was separated from sand by a permanent magnet. As a result of the study theoretical distributions of the magnetic concentration along the device height adapted with the experimental data are received. The study was conducted under various conditions: dry mix, liquid mix, various operating modes of a vibrator.

The received distributions allow under certain initial conditions (for example, at a certain percentage of heavy fraction from the total amount of sand) to calculate probable time for which some preset material layer at the bottom of a jigging machine with a certain concentration of useful fraction is formed. The results of the study have shown that gradient force increases over the time, and environment resistance force on the contrary decreases if at initial time all useful (heavy) fraction was in the top part of sand mass.