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AssigneeStamicarbon B.V.
InventorsAlbert T. Basten, Hubert H. Dreissen
Estimating the term…
The present invention relates to a process for separating scrap essentially consisting of non-ferromagnetic metals into several fractions by specific gravity in which only one heavy separating medium is required. The scrap has been recovered from waste products composed of metals and non-metals by reducing the particle size of the waste through grinding to a size less than 50 mm including particles as small as 0.5 mm. Thereafter, the ferromagnetic components are magnetically separated from the ground waste and the ground waste is fed to a primary specific-gravity separator where non-metallic components are separated from the non-ferromagnetic portion of the ground waste. Thereafter, further separation of the non-ferromagnetic portion in a secondary and, in some cases, tertiary separators is accomplished.
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.degree. to 90.degree., 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.
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.degree. to 90.degree., 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.
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.degree. to 90.degree. and, connected in series with said secondary hydrocyclone, at least one tertiary hydrocyclone having a top angle of the cone-shaped part between 15.degree. to 25.degree., 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.
Dependencies are inferred from the claim text.