US 11,752,503 B2Granted

Anti-plugging discharge grates

AssigneePolycorp Ltd.

InventorsJaime E. Sepulveda, Pramod Kumar

Life of this patent

Estimating the term…

Loading patent…

Abstract

A discharge grate assembly in a discharge end wall system in a mill shell of a grinding mill. The mill shell defines a mill shell chamber in which a charge including grinding balls and ore-bearing rocks is positioned. The mill shell is rotatable about a central axis thereof for comminution of the ore-bearing rocks to form the grinding balls into worn grinding balls and to produce a slurry including liquid and worn rock pieces from the ore-bearing rocks. The discharge grate assembly includes a body with elongate apertures therein, each aperture extending between a first end thereof and a wider second end thereof. The first and second ends of the aperture are partially defined by respective first and second end walls that are at least partially rectilinear, for impeding the worn grinding balls and the worn rock pieces from lodging in the aperture.

Claims22

Dependent claims

A grinding mill, comprising:

a shell defining a mill shell chamber therein in which a charge including grinding balls and ore-bearing rocks is positioned, the shell being rotatable in a predetermined direction about a central axis thereof for comminution of the ore-bearing rocks to produce a mixture including a fluid and worn rock pieces from the ore-bearing rocks, wherein the commnution of the ore-bearing rocks forms the grinding balls into worn grinding balls;
a discharge end wall attached to the shell, the discharge end wall extending between an outer edge thereof connected to the shell and an inner edge thereof at least partially defining a central opening in the discharge end wall;
and
a discharge end wall system, comprising:
a plurality of discharge grate assemblies;
and
a plurality of pulp chambers located between the respective discharge grate assemblies and the discharge end wall, for directing the mixture received therein toward the central opening, to exit the grinding mill therethrough,
wherein each said discharge grate assembly is positioned to screen the mixture flowing from the mill shell chamber into each said pulp chamber respectively as the shell rotates about the central axis,
wherein each said discharge grate assembly is rotatable with the shell about the central axis between a lowered condition, in which the mixture is flowable through at least part of each said discharge grate assembly into the pulp chamber adjacent thereto respectively, and a raised condition, in which the discharge grate assembly is positioned above the charge, and
wherein each said discharge grate assembly comprises:
a body comprising a plurality of elongate apertures therein, formed to screen the mixture flowing therethrough from the mill shell chamber into the pulp chamber,
wherein each said aperture extends between respective first and second ends thereof, the first end having a predetermined first end width and the second end of the aperture having a predetermined second end width that is larger than the first end width,
wherein each said aperture is defined by aperture walls formed in the body;
and
wherein the aperture walls comprise first and second end walls that are at least partially rectilinear and partially define the first and second ends respectively, the first and second end walls being formed to impede the worn grinding balls and the worn rock pieces in the mixture from lodging in the aperture.

12 more elements

A discharge grate assembly in a discharge end wall system in a mill shell of a grinding mill, the mill shell defining a mill shell chamber therein in which a charge including grinding balls and rocks is positioned, the mill shell being rotatable about a central axis thereof for comminution of the rocks to produce a mixture including a fluid and worn rock pieces from the rocks, wherein the comminution of the rocks forms the grinding balls into worn grinding balls, the discharge grate assembly comprising:

a body having a front side facing the mill shell chamber and an opposite rear side, the body comprising a plurality of apertures for permitting the fluid and the rock pieces having a predetermined maximum permitted size sufficiently small to pass through the apertures into a pulp chamber located adjacent to the rear side of the body,
wherein each said aperture is defined by aperture walls formed in the body, each said aperture extending between first and second ends thereof, the first end being defined by a first rectilinear wall having a predetermined first end width and the second end of the aperture being defined by a second rectilinear wall having a predetermined second end width that is greater than the first end width, to impede the worn grinding balls and the worn rock pieces from being lodged in the aperture.

A discharge end wall system mounted on a discharge end wall of a mill shell in a grinding mill, the mill shell defining a mill shell chamber therein in which a charge including rocks and grinding balls is positioned, the mill shell being rotatable about a central axis thereof for comminution of the rocks to produce a mixture including a fluid and worn rock pieces, wherein the comminution of the rocks forms the grinding balls into worn grinding balls, the discharge end wall system comprising:

a plurality of pulp lifters radially arranged on the discharge end wall relative to the central axis, the pulp lifters being located to partially define pulp chambers;
and
a plurality of discharge grate assemblies positioned between the pulp chambers and the mill shell chamber, for screening the mixture moving into the pulp chambers from the mill shell chamber,
wherein each said discharge grate assembly comprises a body with a plurality of elongate apertures therein for screening the mixture,
wherein each said elongate aperture is defined by aperture walls formed in the body, the aperture walls comprising first and second end walls and first and second side walls extending between the respective first and second end walls,
wherein each said aperture is defined by a center line thereof intersecting each of the first and second ends at midpoints thereof, and
wherein the first and second end walls are rectilinear and located orthogonal to the center line of the aperture.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/334,067Filed 28 May 2021 · us provisional application
Priority: 29 May 2020
Published: US 2021/0370310 A12 Dec 2021
Granted: 12 Sep 2023
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

B02C 17/1855
Discharging devices combined with sorting or separating of material: with separator defining termination of crushing zone, e.g. screen denying…
B02C 17/04
Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special…: with…
B02C 17/10
Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special…: with one…
B02C 17/1825
Details: lifting devices