Abstract Method of grinding granular mineral materials in a rotating mill having at least one partially confined grinding zone. The material is fed through a constricted opening into one end of this grinding zone, atmospheric air being permitted to enter in the same way. The coarse material is gradually ground down into finely divided form and is discharged through a constricted opening into an adjoining collection zone and thence discharged from the mill. The rate of feed of the coarse material into the grinding zone and the rate of discharge of the ground material therefrom are so controlled that a pool of the finely ground material is maintained in the grinding zone which is so fluidized that it behaves like a liquid. The apparatus is a tube mill having one or more grinding compartments. If there is only one grinding compartment a narrow collection compartment is located on the downstream side and if there are two grinding compartments the second one is on the downstream side of the narrow compartment. The wall of this compartment adjacent the grinding compartment includes a screen section, and the opposite wall a dam ring and overflow opening.
Inventors
👤 G Fagerholt
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-11-04 12:43
CPC Classifications
B; B02; B02C; B02C17/00; B02C17/04; B02C17/06
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
65 words
The method according to claim 1 wherein: a. the rate of flow of said granular material is controlled by fluidizing the finely divided granular material contained within the grinding and collection zones to form a common pool of fluidized granular material within the mill whereby said finely divided granular material in the collection zone can move backward into the grinding zone via the common pool.
Claim 2
Dependent Claim
35 words
The method according to claim 2 wherein the step of: a. controlling the level of fluidized granular material in the collection zone to finely adjust the rate of flow of granular material through the mill.
Claim 3
Dependent Claim
34 words
The method according to claim 3 wherein: a. the level of fluidized granular material in the collection zone is controlled by controlling the rate of discharge of fluidized granular material from the collection zone.
Claim 4
Dependent Claim
53 words
The method according to claim 4 wherein the rate of discharge of fluidized granular material from the collection zone is controlled by moving at least a portion of said granular material disposed within the collection zone in a path of travel removed from the discharge path of travel of the granular material therefrom.
Claim 5
Dependent Claim
38 words
The method according to claim 5 wherein moving said fluidized granular material out of said discharge path is accomplished by deflecting the flow of said portion of granular material away from the discharge opening in the collection zone.
Claim 6
Dependent Claim
37 words
The method according to claim 6 wherein the deflection of the fluidized granular material flow occurs at a point along the discharge path of travel located in close proximity to the discharge opening in the collection zone.