Flotation Fundamentals
The separation of one component from another by flotation depends on the relative water-wetting ability of the surfaces of the various particle components. Many of the current chemical collectors in use are heteropolar, that is, they contain both a polar charged group and a non-polar uncharged group. When attached to a component surface, these […]
Large Scale Flotation Plants
Although froth flotation was originally developed for mineral separations in the early 20th century, the use of this process has been extended in the last twenty years. From a processing viewpoint, all of these seemingly different industrial uses can be treated using the same theoretical concepts (including equipment and basic underlying chemical reagent structures) that […]
Mineral Processing Froth Flotation
Froth Flotation is a mineral processing process achieving solid-solid separation by taking profit of the chemical attribute leading to the possibility of selectively controlling the relative surface hydrophobicities of the various components mixed in an aqueous medium. Froth flotation is the most common industrial process based on this approach. The term surface hydrophobicity refers to […]
Exploration of Porphyry Copper Deposits
So how do we explore for Porphyry Copper Deposits which are completely covered by barren younger rocks? Well let’s back up a bit, we know that porphyries form under large subduction related volcanoes and that most of these are located under the ring of fire around the subducting pacific plate another fertile subduction zone occurs […]
Ball Mill Critical Speed
A Ball Mill Critical Speed (actually ball, rod, AG or SAG) is the speed at which the centrifugal forces equal gravitational forces at the mill shell’s inside surface and no balls will fall from its position onto the shell. The imagery below helps explain what goes on inside a mill as speed varies. Use our online formula […]
Ball Mill Design/Power Calculation
The basic parameters used in ball mill design (power calculations), rod mill or any tumbling mill sizing are; material to be ground, characteristics, Bond Work Index, bulk density, specific density, desired mill tonnage capacity DTPH, operating % solids or pulp density, feed size as F80 and maximum ‘chunk size’, product size as P80 and maximum and finally the […]
Effect of Grinding Media Charge on Mill Power Draw kW
Maximum power is drawn by a mill when the charge occupies approximately 50% by volume. The power curve becomes very flat in the range above 45%. As a result, mills are seldom run with charge levels greater than 45%. In rod mills, the charge is swollen by particles of feed which separate the rods. If the […]
Mill Steel Charge Volume Calculation
We can calculate the steel charge volume of a ball or rod mill and express it as the % of the volume within the liners that is filled with grinding media. While the mill is stopped, the charge volume can be gotten by measuring the diameter inside the liners and the distance from the top of the charge to […]
Rod Mill Work Index Table
Here is a list presented in table form of Rod Mill Work Index as tested/presented by SME handbook of mineral processing, N.L Weiss Editor, N.Y. 1985. Rapid Determination of Bond Rod-mill Work Index by Craig Taylor on Scribd
List Table of Specific Gravity of Minerals
This table of various minerals (ore, rock types) listed by their tested SG specific gravity complements the BWi List found in earlier post. Source 1: Table of materials reported by Fred Bond Source 2: Outokumpu, The science of comminution Source 3: Equipment and pipelines Source 4: Tenova Bateman mills (AG/SAG, Rod, Ball Mills) Source 5: […]