Process for recovering usable materials from waste material containing metals and non-metals

Claim 2

A process for separating scrap comprised of non-ferromagnetic metals into several fractions by specific gravity, which scrap has been recovered from waste products composed of metals and non-metals in a preliminary treatment, said preliminary treatment comprising the steps of grinding said waste and reducing the particle size to a size ranging up to about 50 mm, magnetically separating ferromagnetic components from the ground waste and separating by a primary specific-gravity separation non-metallic components from the non-ferromagnetic metallic portion of the ground waste, the said process comprising the steps of mixing said non-ferromagnetic metallic portion with a heavy, preferably aqueous suspension medium having a specific gravity of at least 2.2, feeding said mixture to a secondary specific-gravity separator comprising a hydrocyclone having a top angle of the cone-shaped part ranging between 45° to 90°, separating the non-ferromagnetic portion into first and second portions, discharging the first portion comprised of the suspension and a specifically heavy fraction from the tip of the secondary hydrocyclone, said heavy fraction comprised of metals having a specific gravity of more than 3.0, discharging the second portion comprised of the suspension and a specifically lighter fraction from the overflow of the hydrocyclone, said lighter fraction comprised of metals having a specific gravity of less than 3.0, and draining the suspension away from the heavy and lighter fractions.

Claim 3

The process as claimed in claim 1, wherein said reduced scrap contains particles having a size ranging up to about 70 mm, and wherein the ratio of the internal diameter of the vortex finder to that of the tangential feed pipe of the secondary hydrocyclone is less than 1.5, and the ratio of the internal diameter of the feed pipe to that of the cylindrical part of the secondary hydrocyclone between 0.22 and 0.28.

Claim 4

The process according to claim 1, further including the step of mixing the lighter fraction comprised of metals having a specific gravity of less than 3.0 with a suspension medium of the same composition as in said secondary hydrocyclone, feeding said mixture to at least one tertiary specific-gravity separator comprising a hydrocyclone having a top angle of the cone-shaped part ranging between 15° to 25°, separating the lighter fraction, discharging from the tip of the tertiary hydrocyclone, a portion of the suspension medium together with a middle metal fraction comprised of aluminum, discharging from the overflow of the tertiary hydrocyclone another portion of the suspension medium together with a lightest metal fraction comprised of lighter metals and alloys and draining the suspension medium away from the middle and lightest fractions.

Claim 5

The process according to claim 3, wherein the specifically lighter fraction and heavy suspension medium are passed to a supply vessel provided with an overflow, and wherein the supply vessel is mounted higher than the tertiary hydrocyclone so that the mixture of the suspension medium and the lighter fraction is supplied to the tertiary hydrocyclone at a predetermined, constant pressure.

Claim 6

The process according to claim 4, wherein the heavy suspension passed to the supply vessel is composed of the suspension medium which is discharged together with said specifically lighter fraction at the overflow of the secondary hydrocyclone and of the suspension medium which is drained from the material discharged at the tip of the secondary hydrocyclone.

Claim 7

The process as claimed in claim 3, wherein the primary specific-gravity separation includes the steps of mixing the ground waste from which the ferromagnetic component has been removed with a separating medium comprised of water, feeding the mixture to at least one primary hydrocyclone, separating the components in the mixture, discharging from the tip of the primary hydrocyclone a portion of the separation medium together with the nonferromagnetic metal portion of the ground waste, discharging from the overflow of the primary hydrocyclone another portion of the separating medium together with non-metallic components within the ground waste and draining the separating medium from the separated portions of the ground waste.

Claim 8

The process as claimed in claim 6 including the additional steps of recycling the water used in the primary hydrocyclone by passing at least part of the water through at least one cyclone-thickener, discharging accumulated fine impurities from the tip of the cyclone-thickener, discharging purified water from the overflow of the cyclone-thickener, spraying the purified water on the desired draining metal fractions, regenerating the diluted suspension medium used in the secondary and tertiary hydrocyclones drained from the portions separated therein, and collecting the water withdrawn during the regenerating for use in the primary hydrocyclone.

Claim 9

The process as claimed in claim 1, wherein the primary specific-gravity separation includes the steps of mixing the ground waste from which the ferromagnetic component has been removed with a separating medium comprised of water feeding the mixture to at least one primary hydrocyclone, separating the components in the mixture, discharging from the tip of the primary hydrocyclone a portion of the separation medium together with the non-ferromagnetic metal portion of the ground waste, discharging from the overflow of the primary hydrocyclone another portion of the separating medium together with non-metallic components within the ground waste and draining the separating medium from the separated portions of the ground waste.

Claim 10

The process as claimed in claim 8 including the additional steps of recycling the water used in the primary hydrocyclone by passing at least part of the water through at least one cyclone-thickener, discharging accumulated fine impurities from the tip of the cyclone-thickener, discharging purified water from the overflow of the cyclone-thickener, spraying the purified water on the desired draining metal fractions, regenerating the diluted suspension medium used in the secondary hydrocyclone drained from the portions separated therein, and collecting the water withdrawn during the regenerating for use in the primary hydrocyclone.

Claim 11

The process according to claim 1, wherein the step of draining the metal fractions of the suspension includes the additional step of submerging the metal fractions in a washing liquid.

Claim 12

The process according to claim 1, wherein the waste products comprise discarded cars or parts thereof.

Claim 13

An installation for separating scrap comprised of non-ferromagnetic metals into several fractions by specific-gravity, which scrap has been recovered from waste products composed of metals and non-metals by treatment in a primary installation comprising means for reducing in size and grinding said waste so as to produce particles ranging in size up to about 70 mm, means for magnetically separating ferromagnetic components from the ground waste and a primary specific-gravity separator for separating non-metallic components from the non-ferromagnetic portion of said ground waste, said installation in combination with said primary installation comprising at least one secondary specific-gravity separator comprising a hydrocyclone having a top angle of the cone-shaped part ranging between 45° to 90°, means for mixing said non-ferromagnetic metal scrap together with a heavy suspension medium to form a mixture thereof, means for conveying this mixture to at least one said secondary hydrocyclone, first suspension medium recovery means for collecting heavy medium for direct mixing with said non-ferromagnetic metal scrap and second suspension medium conveying means for recovery of dilute suspension medium, said second recovery means including draining screens and rinsing screens positioned respectively adjacent the discharge-opening at the tip of the secondary hydrocyclone and at the overflow of the secondary hydrocyclone in order to drain the suspension from the discharged fractions and regeneration means for regeneration of the diluted suspension medium from the rinsing screens wherein the ratio of the internal diameter of the vortex finder to that of the tangential feed pipe of the secondary cyclone is less than 1.5, and wherein the ratio of the internal diameter of the feed pipe to that of the cylindrical part of the secondary cyclone is between 0.22 and 0.28.

Claim 14

An installation for separating scrap comprised of non-ferromagnetic metals into several fractions by specific-gravity, which scrap has been recovered from waste products composed of metals and non-metals by treatment in a primary installation comprising means for reducing in size and grinding said waste so as to produce particles ranging in size up to about 70 mm, means for magnetically separating ferromagnetic components from the ground waste and a primary specific-gravity separator for separating non-metallic components from the non-ferromagnetic portion of said ground waste, said installation in combination with said primary installation comprising at least one secondary specific-gravity separator comprising a hydrocyclone having a top angle of the cone-shaped part ranging between 45° to 90°, means for mixing said non-ferromagnetic metal scrap together with a heavy suspension medium to form a mixture thereof, means for conveying this mixture to at least one said secondary hydrocyclone, first suspension medium recovery means for collecting heavy medium for direct mixing with said non-ferromagnetic metal scrap and second suspension medium conveying means for recovery of dilute suspension medium, said second recovery means including draining screens and rinsing screens positioned respectively adjacent the discharge-opening at the tip of the secondary hydrocyclone and at the overflow of the secondary hydrocyclone in order to drain the suspension from the discharged fractions and regeneration means for regeneration of the diluted suspension medium from the rinsing screens wherein the ratio of the internal diameter of the vortex finder to that of the tangential feed pipe of the secondary cyclone is less than 1.5, and wherein the ratio of the internal diameter of the feed pipe to that of the cylindrical part of the secondary cyclone is between 0.22 and 0.28.

Claim 15

An installation for separating scrap comprised of non-ferromagnetic metals into several fractions by specific gravity, which scrap has been recovered from waste products composed of metals and non-metals by treatment in a primary installation comprising means for reducing in size and grinding said waste, so as to produce particles ranging in size up to about 50 mm, means for magnetically separating ferromagnetic components from the ground waste, a primary specific-grvity separator for separating non-metallic components from the non-ferromagnetic portion of said ground waste, said installation in combination with said primary installation comprising at least one secondary hydrocyclone having a top angle of the cone-shaped part between 45° to 90° and, connected in series with said secondary hydrocyclone, at least one tertiary hydrocyclone having a top angle of the cone-shaped part between 15° to 25°, means for mixing said non-ferromagnetic metal scrap together with a heavy suspension medium to form a mixture thereof, means for conveying this suspension medium to said secondary hydrocyclone and means for supplying the fraction discharged at the overflow of said secondary hydrocyclone to said tertiary hydrocyclone together with a heavy suspension medium of the same composition as in said secondary hydrocyclone, draining screens and rinsing screens positioned so as to receive the fractions discharged at the discharge-opening at the tip of said secondary hydrocyclone, at the overflow of said tertiary hydrocyclone and the discharge-opening at the tip of said tertiary hydrocyclone, and means for regenerating the diluted suspension withdrawn from said rinsing screens.

Claim 16

An installation for separating scrap comprised of non-ferromagnetic metals into several fractions by specific gravity, which scrap has been recovered from waste products composed of metals and non-metals by treatment in a primary installation comprising means for reducing in size and grinding said waste, so as to produce particles ranging in size up to about 50 mm, means for magnetically separating ferromagnetic components from the ground waste, a primary specific-grvity separator for separating non-metallic components from the non-ferromagnetic portion of said ground waste, said installation in combination with said primary installation comprising at least one secondary hydrocyclone having a top angle of the cone-shaped part between 45° to 90° and, connected in series with said secondary hydrocyclone, at least one tertiary hydrocyclone having a top angle of the cone-shaped part between 15° to 25°, means for mixing said non-ferromagnetic metal scrap together with a heavy suspension medium to form a mixture thereof, means for conveying this suspension medium to said secondary hydrocyclone and means for supplying the fraction discharged at the overflow of said secondary hydrocyclone to said tertiary hydrocyclone together with a heavy suspension medium of the same composition as in said secondary hydrocyclone, draining screens and rinsing screens positioned so as to receive the fractions discharged at the discharge-opening at the tip of said secondary hydrocyclone, at the overflow of said tertiary hydrocyclone and the discharge-opening at the tip of said tertiary hydrocyclone, and means for regenerating the diluted suspension withdrawn from said rinsing screens.

Claim 17

An installation according to claim 13, wherein the ratio of the internal diameter of the vortex finder to that of the tangential feed pipe of said secondary cyclone is less than 1.5, and wherein the ratio of the internal diameter of the feed pipe to that of the cylindrical part of said secondary cyclone is between 0.22 and 0.28.