Autogenous Mill

Sizing of the mill is also affected by the arrangement of the mill and water wheel. 

For mill effluent to discharge into the water wheel as in Fig. 3, the mill diameter, 

must approximate the water wheel diameter, KD. (More precisely, the sum of the pitch circle diameters of the sprocket and mill must exceed KD plus the outside diameter of the mill outlet pipe.) Turning of stone in the mill exerts a resistance torque of /Ty( 1 - e) A A sin4xT2, reduced by the mechanical advantage through the drive to the water wheel by a factor of d-i-(KD), where d - sprocket pitch circle diameter. As before, the water wheel drive torque is M - 0.12 5n V-K (AT2 - 1)LD3. If A KD, the maximum sprocket diameter, d, that will provide the necessary mechanical advantage is  

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Raw material for dry process plants is ground in closed-circuit ball mills with air separators, which may be set for any desired fineness. Drying is usually carried out in separate units, but waste heat can be utilized directiy in the mill by coupling the raw mill to the kiln. Autogenous mills, which operate without grinding media are not widely used. For suspension preheater-type kilns, a roUer mill utilizes the exit gas from the preheater to dry the material in suspension in the mill. 

The pebble mill is a tube mill with flint or ceramic pebbles as the grinding medium and may be lined with ceramic or other nonmetaUic liners. The rock-pebble mill is an autogenous mill in which the... 

FIG. 20-57 Autogenous mill circuit. Simphfied flow diagram of the Cleveland-Cliffs Iron Co. Empire iron-mine concentrator with two autogenous wet-grinding stages. To convert inches to centimeters, multiply hy 2.54 to convert feet to centimeters, multiply hy 30.5. 

Hard and tough Mica Scrap and powdered metals Jaw crushers Gyratory crushers Cone crushers Autogeneous mills Ball, pebble, rod and cone mills Tube mills Vibration mills Ball, pebble and cone mills Tube mills Vibration and vibro-energy mills Fluid-energy mills Moh s hardness 5-10, but includes other tough materials of lower hardness... 

Abrasive scouring - autogenous mill, and Sodium carbonate. 

Neutralization plant, oblique view. Autogenous mill support and drive detail. 

Autogenous mill effluent drives water wheel that rotates mill. 

The autogenous mill initially neutralized mine wastewater by as much as 3.3 pH units to pH 8.4, a similar degree of initial neutralization to that observed in the limestone-packed flume, and exceeding the design neutralization from pH 4.0 to 6.3,... 

S. Morrell, A new autogenous and semi-autogenous mill model for scale-up, design and optimisation, Miner. Eng. 17 (2004) 437-445. 

Autogeneous mills use the grinding stock itself as grinding media, but can only be used for fine crushing. They have the lowest length to diameter (L/D) ratio of 0.25, whereas rod and ball mills can have a L/D ratio up to 6. 

Jaw crushers Gyratory crushers Cone crushers Autogeneous mills... 

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