Method for sorting a collection of bodies comprising cemented carbide bodies and non-cemented carbide bodies

Patent metadata

Field	Value
Publication number	US-9770720-B2
Application number	US-201514730279-A
Country	US
Kind code	B2
Filing date	Jun 4, 2015
Priority date	Jun 5, 2014
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

The disclosure relates to a method for sorting a collection of bodies including cemented carbide bodies and non-cemented carbide bodies. A melt having one or more of bismuth, tin and lead and having a density in the range of 7.0-12.0 g/cm 3 is provided. The collection is subjected to a sorting process based on density difference by providing the collection in the melt and allowing the bodies to be sorted into a first group at a top surface of the melt and a second group at a bottom of the melt. The first group includes non-cemented carbide bodies having a density lower than the density of the melt and the second group includes cemented carbide bodies having a density higher than the density of the melt. The present disclosure also relates to a method for recycling of cemented carbides comprising the sorting method and recycling of the second group.

First claim

The invention claimed is:

1. A method for sorting a collection of bodies including cemented carbide bodies and non-cemented carbide bodies, the method comprising the steps of:
providing a melt including one or more of bismuth, tin and lead and having a density in the range of from 7.0 g/cm 3 to 12.0 g/cm 3 ;
subjecting said collection to a sorting process based on a density difference by providing said collection in said melt and allowing said collection to be sorted into a first group of bodies collected at a top surface of said melt and a second group of bodies collected at a bottom of said melt based on said density difference, said first group of bodies comprising non-cemented carbide bodies of said collection having a density lower than said density of said melt and said second group of bodies comprising cemented carbide bodies having a density higher than said density of said melt, the sorting process being based on the density difference between the density of the melt and the density of the bodies;
separating said first group of bodies from said melt; and
separating said second group of bodies from said melt.

2. The method according to claim 1 , wherein said melt has a density in the range of from 8.0 g/cm 3 to 11.0 g/cm 3 .

3. The method according to claim 1 , wherein said melt has a density in the range of from 8.0 g/cm3 to 10.0 g/cm3.

4. The method according to claim 1 , wherein said melt has a density in the range of from 8.5 g/cm 3 to 9.5 g/cm 3 .

5. The method according to claim 1 , wherein said melt comprises one or more of bismuth, tin and lead.

6. The method according to claim 5 , wherein said melt is selected from the group of a mixture consisting of bismuth and tin, a mixture consisting of bismuth and lead, a mixture consisting of lead and tin, and a mixture consisting of bismuth, lead and tin.

7. The method according to claim 6 , wherein said melt comprises a mixture of bismuth and tin and having a density in the range of from 8.0 g/cm 3 to 9.5 g/cm 3 .

8. The method according to claim 6 , wherein said melt comprises a mixture of lead and tin and having a density in the range of from 7.5 g/cm 3 to 9.5 g/cm 3 .

9. The method according to claim 6 , wherein said melt comprises a mixture of bismuth and lead and having a density in the range of from 10.2 g/cm 3 to 10.5 g/cm 3 .

10. The method according to claim 6 , wherein said melt comprises a mixture of bismuth, tin and lead and having a density in the range of from 8.5 g/cm 3 to 9.5 g/cm 3 .

11. The method according to claim 6 , wherein said mixture is of eutectic composition.

12. The method according to claim 1 , wherein the temperature of said melt is <400° C.

13. The method according to claim 1 , wherein the method further comprises a step of providing a layer of glycerol on the top surface of said melt.

14. The method according to claim 1 , wherein said melt is stirred during said sorting process.

15. The method according to claim 1 , wherein said non-cemented carbide bodies comprises cermet bodies.

16. A method for recycling of cemented carbides comprising the steps of:
providing a melt including one or more of bismuth, tin and lead and having a density in the range of from 7.0 g/cm 3 to 12.0 g/cm 3 ;
sorting a collection of bodies including cemented carbide bodies and non-cemented carbide bodies so as to obtain a separate first group of bodies comprising non-cemented carbide bodies and a separate second group of bodies comprising cemented carbide bodies;
subjecting said collection to a sorting process based on a density difference by providing said collection in said melt and allowing said collection to be sorted into the first group of bodies collected at a top surface of said melt and a second group of bodies collected at a bottom of said melt based on said density difference, said first group of bodies comprising non-cemented carbide bodies of said collection having a density lower than said density of said melt and said second group of bodies comprising cemented carbide bodies having a density higher than said density of said melt, the sorting process being based on the density difference between the density of the melt and the density of the bodies;
separating said first group of bodies from said melt;
separating said second group of bodies from said melt; and
recycling said second group of bodies.

Assignees

• Sandvik Intellectual Property

Inventors

• Jutterstrom Ulf

Classifications

• C01B31/00

  Chemistry & Metallurgy · mapped topic

• B22F8/00

  Manufacture of articles from scrap or waste metal particles · CPC title

• C22C12/00

  Alloys based on antimony or bismuth · CPC title

• C22B7/004

  separating two or more metals by melting out (liquation), i.e. heating above the temperature of the lower melting metal component(s); by fractional crystallisation (controlled freezing) · CPC title

• B22F2009/001

  from scrap particles · CPC title