US3970546A — Method and apparatus for separating non-ferrous m…

Claim 1

Independent Claim 170 words

A method for separating non-ferrous metal from waste material comprising non-ferrous metal and low conductivity conductive material; said method comprising the steps of: a. sizing the waste material to a particle size not more than about 4 inches; b. feeding the sized waste material particles to a grounded electrode; c. pinning the waste material particles to said grounded electrode by subjecting the waste material particles to ion bombardment from a D.C. corona discharge electrode; d. maintaining the low conductivity conductive particles pinned to said grounded electrode by subjecting the waste material particles to discharge from an A.C. corona discharge electrode; e. inducing a charge, opposite in polarity to said D.C. corona discharge electrode, on the non-ferrous metal particles and attracting the non-ferrous metal particles away from said grounded electrode by subjecting the waste material particles to an electrostatic field imposed between a static D.C. electrode and said grounded electrode; said static D.C. electrode having the same polarity as said D.C. corona discharge electrode; and f. collecting the non-ferrous metal particles.

Claim 2

Independent Claim 170 words

A method for separating non-ferrous metal from waste material comprising non-ferrous metal and low conductivity conductive material; said method comprising the steps of: a. sizing the waste material to a particle size not more than about 4 inches; b. feeding the sized waste material particles to a grounded electrode; c. pinning the waste material particles to said grounded electrode by subjecting the waste material particles to ion bombardment from a D.C. corona discharge electrode; d. maintaining the low conductivity conductive particles pinned to said grounded electrode by subjecting the waste material particles to discharge from an A.C. corona discharge electrode; e. inducing a charge, opposite in polarity to said D.C. corona discharge electrode, on the non-ferrous metal particles and attracting the non-ferrous metal particles away from said grounded electrode by subjecting the waste material particles to an electrostatic field imposed between a static D.C. electrode and said grounded electrode; said static D.C. electrode having the same polarity as said D.C. corona discharge electrode; and f. collecting the non-ferrous metal particles.

Claim 3

Dependent Claim 33 words

A method as recited in claim 1 further comprising the step of subjecting the waste material to magnetic separation to remove ferrous metal prior to feeding the waste material to the grounded electrode.

Claim 4

Dependent Claim 39 words

A method as recited in claim 1 further comprising the step of subjecting the waste material to preliminary classification to remove fine particles and material of low bulk density prior to feeding the waste material to the grounded electrode.

Claim 5

Dependent Claim 16 words

A method as recited in claim 3 wherein said preliminary classification is effected by air classification.

Claim 6

Dependent Claim 81 words

A method as recited in claim 4 wherein the waste material fed to said grounded electrode has a bulk density greater than about 1.0 g./cm. 3 ; the size ratio of the largest to smallest particles in said material fed to the grounded electrode is not more than about 8 to 1, and said material is fed to the electrode at a rate lying in the range from about 50 to about 100 pounds per hour per inch of electrode length.

Claim 7

Dependent Claim 83 words

A method as recited in claim 5 wherein the waste material fed to the grounded electrode has a bulk density greater than about 2.0 g./cm. 3 ; the size ratio of the largest to smallest particles in the material fed to the grounded electrode is not more than about 3 to 1, and said waste material is fed to the grounded electrode at a rate lying in the range from about 100 to about 200 pounds per hour per inch of electrode length.

Claim 8

Dependent Claim 26 words

A method as recited in claim 1 further comprising the step of reducing the moisture content of the waste material to less than about 3 percent.

Claim 9

Dependent Claim 62 words

A method as recited in claim 7 wherein the sizing of the waste material is effected by shredding and screening; the moisture content of the waste material is reduced to less than about 1 percent; and the resistivity of said low conductivity conductive material after reduction in the moisture content is greater than about 10 - 2 ohms per centimeter at 20°C.

Claim 10

Dependent Claim 16 words

A method as recited in claim 1 wherein said grounded electrode comprises a rotating conductive roll.

Claim 11

Dependent Claim 24 words

A method as recited in claim 9 wherein the diameter of said roll lies in the range from about 6 to about 36 inches.

Claim 12

Dependent Claim 59 words

A method as recited in claim 10 wherein the diameter of said roll lies in the range from about 14 to about 24 inches; the rate of rotation of said roll lies in the range from about 8 to about 25 revolutions per minute; and the polarity of said D.C. corona electrode and said D.C. static electrode is negative.

Claim 13

Dependent Claim 31 words

A method as recited in claim 9 wherein waste material having a particle size less than about 1/8 inch is removed prior to feeding the waste material to said grounded electrode.

Claim 14

Dependent Claim 52 words

a method as recited in claim 12 wherein the particle size of the waste material fed to the grounded electrode lies in the range from about 1/4 inch to about 3 inches; and the waste material particles have an average shape factor lying in the range from about 15 to about 25.

Claim 15

Dependent Claim 36 words

A method as recited in claim 1 wherein the D.C. corona electrode, the A.C. corona electrode and the D.C. static electrode are charged with potentials lying in the range from about 20 to about 40 kilovolts.

Claim 16

Dependent Claim 36 words

A method as recited in claim 14 wherein the D.C. corona electrode, the A.C. corona electrode, and the D.C. static electrode are charged with potentials lying in the range from about 25 to about 35 kilovolts.

Claim 17

Dependent Claim 150 words

A method as recited in claim 1 wherein the collected non-ferrous metal material includes residual non-conductive and low conductivity conductive material, further comprising the steps of: feeding the collected material to a second grounded electrode; pinning the collected material to said second grounded electrode by subjecting the collected material to ion bombardment from a second D.C. corona discharge electrode; maintaining the low conductivity conductive particles pinned to said second grounded electrode by subjecting the collected material to discharge from a second A.C. corona discharge electrode; inducing a charge on the non-ferrous metal material opposite in polarity to said second D.C. corona discharge electrode and attracting the non-ferrous metal material away from said second grounded electrode by subjecting the collective material to an electrostatic field imposed between a second static electrode and said second grounded electrode; said second static electrode having the same polarity as said second D.C. corona discharge electrode.

Claim 18

Dependent Claim 31 words

A method as recited in claim 1 wherein the collected non-ferrous metal material includes residual amounts of other materials, further comprising the step of subjecting the collected material to air tabling.

Claim 19

Dependent Claim 165 words

Apparatus for separating non-ferrous metal from waste material comprising non-ferrous metal and low conductivity conductive material, said apparatus comprising: a. a grounded conductive roll adapted for rotation in one direction; b. means for feeding waste material to said roll at a first sequential point; c. a D.C. corona electrode at a second sequential point in the direction of rotation of the roll, spaced from the periphery of the roll and adapted to subject material on the roll to D.C. corona discharge; d. an A.C. corona electrode at a third sequential point in the direction of rotation of the roll, spaced from the periphery of the roll and adapted to subject material on the roll to A.C. corona discharge; and e. a D.C. static electrode at a fourth sequential point in the direction of rotation of the roll, spaced from the periphery of the roll and adapted to subject material on the roll to an electrostatic field imposed between said static electrode and the grounded roll.

Claim 20

Dependent Claim 165 words

Apparatus for separating non-ferrous metal from waste material comprising non-ferrous metal and low conductivity conductive material, said apparatus comprising: a. a grounded conductive roll adapted for rotation in one direction; b. means for feeding waste material to said roll at a first sequential point; c. a D.C. corona electrode at a second sequential point in the direction of rotation of the roll, spaced from the periphery of the roll and adapted to subject material on the roll to D.C. corona discharge; d. an A.C. corona electrode at a third sequential point in the direction of rotation of the roll, spaced from the periphery of the roll and adapted to subject material on the roll to A.C. corona discharge; and e. a D.C. static electrode at a fourth sequential point in the direction of rotation of the roll, spaced from the periphery of the roll and adapted to subject material on the roll to an electrostatic field imposed between said static electrode and the grounded roll.

Claim 21

Dependent Claim 23 words

Apparatus as recited in claim 18 wherein said roll has a diameter lying in the range from about 6 to about 36 inches.

Claim 22

Dependent Claim 23 words

Apparatus as recited in claim 19 wherein said roll has a diameter lying in the range from about 14 to about 24 inches.

Claim 23

Dependent Claim 19 words

Apparatus as recited in claim 18 wherein said D.C. corona electrode and said A.C. corona electrode are focusing electrodes.

Claim 24

Dependent Claim 58 words

Apparatus as recited in claim 18 wherein said D.C. corona electrode, said A.C. corona electrode, and said D.C. static electrode are each spaced from said roll a distance lying in the range from about 2 to about 4 inches and are adjustably mounted whereby the spacing between each of said electrodes and said roll can be individually varied.

Claim 25

Dependent Claim 54 words

Apparatus as recited in claim 18 further comprising a splitter at a fifth point in the direction of rotation of said roll spaced from the roll a distance lying in the range from about 2 to about 4 inches and adjustably mounted whereby the spacing between said splitter and the roll can be varied.

Claim 26

Dependent Claim 39 words

Apparatus as recited in claim 18 further comprising a second D.C. corona electrode between said D.C. corona electrode and said A.C. corona electrode, spaced from said roll and adapted to subject material on the roll to D.C. corona discharge.

Claim 27

Dependent Claim 39 words

Apparatus as recited in claim 18 further comprising a second A.C. corona electrode between said A.C. corona electrode and said D.C. static electrode, spaced from said roll and adapted to subject material on the roll to A.C. corona discharge.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1979-07-20	1980-01-19	1980-07-20	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1983-07-20	1984-01-19	1984-07-20	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1987-07-20	1988-01-19	1988-07-20	$7700.00	Window Closed / Lapsed

Method and apparatus for separating non-ferrous metal from waste material

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