US 4,398,673 AGranted

Method of classifying and comminuting a gypsum ore or the like

AssigneeDomtar Industries Inc.

InventorWalter L. Gonnason

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Abstract

A method is disclosed for separating a relatively soft component from a relatively hard component of mineral ore and then comminuting the softer component. The separation is performed by impact crushing the ore to reduce the softer component to particulate material of a smaller dimension than that of the harder component after which the components are separated by screening. The comminution is performed by further impact crushing the softer component to further reduce same and separating sufficiently small particles. Relatively large particles are also removed and the remainder of the softer component is recycled through the comminution process. The method is primarily applicable to the separation of chert from gypsum and comminuting the gypsum in the processing of gypsum ore.

Claims6

Dependent claims

A method of concentrating and comminuting the gypsum component of a gypsum ore having gypsum and chert components characterized by substantial differences in hardness, the steps comprising:

reducing the ore to a partially fragmented product by impaction at a velocity in the range of 7,800 to 9,800 feet per minute against a hard surface which will fracture a substantially greater proportion of the gypsum component;
separating by size the partially fragmented product into a first waste product and a first stage product, the first stage product being smaller in size than the first waste product, the particles of the first stage product being in the range of no greater than 1/2 inch in cross section;
impacting said first stage product at a velocity in the range of 14,100 to 16,400 feet per minute against a hard surface which will fracture a substantially greater proportion of the gypsum component than of the chert component to produce a partially comminuted product;
separating by size the partially comminuted product into finished product, recycle product, and second waste product, the products being of increasing size from finished to second waste product, the particles of the finished product being in the range of no greater than 0.0058 inches in cross section, the particles of the second waste product being in the range of greater than 0.0331 inches in cross section;
and
returning the recycle product to the impacting step.

3 more elements

A method of concentrating and comminuting the gypsum component of a gypsum ore having gypsum and chert components characterized by substantial differences in hardness, the steps comprising:

as a first stage, reducing the ore to lumps;
impacting the lumps against a first hard surface at a first impact velocity in the range of 7,800 to 9,800 feet per minute which will fracture a substantially greater proportion of the gypsum component than of the chert component to produce a partially fragmented product;
separating by size the partially fragmented product into first stage product and first waste product, the particles of the first stage product being in the range of no greater than 0.5 inches in cross section, the first waste product being larger than the first stage product;
as a second stage, impacting said first stage product against a second hard surface at a second impact velocity in the range of 14,100 to 16,400 feet per minute which will again fracture a substantially greater proportion of the gypsum component than the chert component to product a partially comminuted product;
separating by size the partially comminuted product into finished product, recycle product, and second waste product, the particles of the finished product being in the range of no greater than 0.0058 inches in cross section, the particles of the recycle product being in the range of greater than 0.0058 and no greater than 0.0331 inches in cross section, the particles of the second waste product being in the range of greater than 0.0331 inches in cross section;
and
returning the recycle product to the second stage for further processing.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/210,011Filed 24 Nov 1980 · continuation in part
Priority: 12 Jun 1980
Granted: 16 Aug 1983
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

B02C 23/14
Separating or sorting of material, associated with crushing or disintegrating: with more than one separator
B02C 13/1807
With beaters rigidly connected to the rotor: the material to be crushed being thrown against an anvil or impact plate
B02C 19/0056
Other disintegrating devices or methods: specially adapted for specific materials not otherwise provided for
B02C
Crushing, pulverising, or disintegrating in general

Family

Serial158,947Parent of this continuation-in-part · filed 12 Jun 1980
US 4,398,673 AThis patent

From the US filing history. Foreign family members aren’t listed.

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