Grinding

Autogeneous Grinding VS Steel Grinding Media in Flotation

In grinding, the use of steel media in a rod/ball mill circuit clearly diminishes the subsequent froth flotation performance over purely autogenous grinding. The use of recycle water in grinding also clearly diminishes the subsequent froth flotation performance associated with fresh tap water. Some of these flotation deficiencies are recoverable by using stronger collectors at … Read more

How to Reduce Ball Mill Overload Risk

Two different circumstances must be addressed for the reduction or elimination of overload risk: a) in existing operations, or b) in the design of new grinding circuits. The methods necessary are in the first case an adjustment of operating conditions; and in the second an adjustment of mill shapes. Existing Operations: from Equation (1) for … Read more

Ball Mill Circuit Classification System Efficiency

Fines may be defined as any material smaller than a specified product size, and “coarse” as any material that is larger. The target 80 percent passing size of the grinding circuit product is a convenient reference point, as it is often used to express the grind size objective. This size is close to the modal … Read more

SAG Mill Components

Once the basic operating conditions have been defined for the mill designer then, and only then, can he begin taking into account shell and head stresses and trunnion bearing sizes required to carry the load and to give the required openings for feeding and discharging the mills. Mill heads are key structural components of any … Read more

AG – SAG Autogenous & Semi-Autogenous Grinding Mill Testing

Ff the drill cores indicate that the ore could contain sufficient lumps in the sizes needed for ore media in autogenous and semi-autogenous grinding, then bulk samples (750 kg) of mine run or primary crushed ore, with an even distribution by quantity in the size fractions between 100 mm and 200 mm, should be obtained … Read more

Slurry Flow Rate Through a Mill

The factors upon which the rate of flow of the pulp through a mill depends appear not to have received extensive investigation. In an article by Anselm translated by Pearson a method for the calculation of the time of passage of cement through a ball mill was given. The basis of the method is that the … Read more

Grinding Mill Surging

The phenomenon of “surging” in a mill is a subject upon which very little has been written; presumably because it is a condition which cannot be tolerated in mill operation and which must be eliminated by variation of some or many of the physical dimensions or characteristics of the mill or mill charge.  The phenomenon known … Read more

Effect of Grinding Media on Milling

In the previous chapter the influence of the various physical quantities defining the mill and mill charge has been studied in connection with the performance of a mill as a device for the creation of new surface in the powder. For some purposes, however, it is also desirable that the product should have a preferred … Read more