Due to the favorable effect of water, it is not difficult to conclude that frictional grinding should work better in water. Water is believed to play two roles in this process: one is its wetting action, facilitating the dispersion of the agglomerated and adhered particles while the other is its drag force, hindering the entrainment of nonmagnetic particles in the agglomerates of magnetic particles to some extent.
The introduction of several percent moisture without heated gas sweeping can virtually halt grinding of fine material, until increased water addition carries the material through the sticky stage into the normal wet grinding range of sixty to eighty percent solids by weight.
What water does is kind of provide a mode of transportation for the ore. How Water Impacts Grinding It works in this way, as the rock and the water enter the mill the water will wash the finer particles deeper into the mill leaving the coarse material at entrance of the rod load.
The bad side of the water is that it takes up space. The more water that is added, the faster the ore will go through the mill. This means the time it has to be ground will be reduced and a poor grind will result. At the other extreme, if not enough water is used, the ore will not be able to flow through the mill. The result is the ore will not be able to move into the rod load. Because there isnt enough water to carry the ground material deeper into the mill the ore begins to pile up at ...
Table A.23. Effects of moisture content, and screen size on moisture loss during grinding of loblolly pine woodchips . ..... 142 Table A.31. Effects of moisture content and screen size on the oven dried bulk density of loblolly
Water scarcity dictates to limit the use of water in ore processing plants particularly in arid regions. Since wet grinding is the most common method for particle size reduction and mineral liberation, there is a lack of understanding about the effects of dry grinding on downstream separation processes such as flotation.
The throughput and specific rate of breakage of corncobs were very low compared to corn and decreased with increasing moisture content. The energy required for grinding corncobs was higher than that for corn. The particle size of ground corn was smaller than that of ground cobs; however, there were no significant differences across moisture levels.