Granulated slag products and processes for their production

Patent metadata

Field	Value
Publication number	US-10167423-B2
Application number	US-201515315766-A
Country	US
Kind code	B2
Filing date	Mar 20, 2015
Priority date	Jun 3, 2014
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A process for preparing solid slag granules from a molten slag composition comprises: (a) providing the molten slag composition; (b) converting the molten slag composition into the solid slag granules in a dispersion apparatus; and (c) sorting the solid slag granules by shape in a separator to produce a plurality of fractions having different sphericities. Granular slag products comprise one or more fractions of solid slag granules produced by the process, and include proppants, roofing granules, catalyst supports, which may be porous or non-porous, and coated or uncoated.

First claim

What is claimed is:

1. A process for preparing solid slag granules from a molten slag composition, comprising:
(a) providing the molten slag composition;
(b) converting the molten slag composition into the solid slag granules in a dispersion apparatus; and
(c) sorting the solid slag granules by shape in a separator to produce a plurality of fractions having different sphericities, wherein at least one of the fractions produced by said sorting consists of said solid slag granules having an average sphericity of greater than 0.6, wherein at least one of the fractions produced by said sorting consists of said solid slag granules having an average sphericity of less than 0.6, and wherein a ratio of said solid slag granules having an average sphericity of greater than 0.6 to said solid slag granules having an average sphericity of less than 0.6 is controllable by adjustment of one or more of the following parameters:
(a) the temperature of the molten slag composition; and
(b) an angle between a gas stream and a falling stream of said molten slag composition, where the dispersion apparatus comprises an atomization apparatus.

2. The process of claim 1 , wherein the dispersion apparatus comprises an atomization apparatus, and said step of converting the molten slag composition into the solid slag granules comprises atomizing the molten slag composition by contacting the molten slag composition with a gas stream in said dispersion apparatus.

3. The process of claim 2 , wherein the atomization apparatus comprises a blower, and said atomizing of the molten slag composition comprises using said blower to blow said gas stream into a falling stream of said molten slag composition in said dispersion apparatus, thereby separating the falling stream of said molten slag composition into droplets which solidify to form said solid slag granules.

4. The process of claim 3 , wherein the blower is adapted to produce a maximum total pressure of less than about 80 inches of water.

5. The process of claim 3 , wherein the solid slag granules are non-porous.

6. The process of claim 3 , wherein the atomization apparatus further comprises an impact plate, and at least some of the solid slag granules are produced by droplets striking the impact plate, wherein said solid slag granules produced by droplets striking the impact plate have an average sphericity of less than 0.6.

7. The process claim 3 , wherein the molten slag composition comprises free iron, and wherein the metallic iron is substantially completely oxidized during said atomizing of the molten slag composition, such that the solid slag granules are substantially non-magnetic.

8. The process of claim 2 , wherein the gas stream comprises air.

9. The process of claim 1 , wherein at least one of the fractions produced by said sorting consists of said solid slag granules having an average sphericity and/or roundness of from 0.7 to about 0.9.

10. The process of claim 1 , wherein said at least one fraction having an average sphericity of less than 0.6 includes elongate granules.

11. The process of claim 10 , wherein the elongate granules include dumbbell-shaped granules and/or fractured dumbbell-shaped granules.

12. The process of claim 1 , further comprising a step of sorting the solid slag granules by density.

13. The process of claim 1 , further comprising a step of mixing the molten slag composition with a density-reducing additive prior to and/or simultaneously with said step of converting the molten slag composition into the solid slag granules in the dispersion apparatus.

14. The process of claim 13 , wherein the step of mixing the molten slag composition with the density-reducing additive comprises injecting the density-reducing additive into the molten slag composition.

15. The process of claim 13 , wherein the density-reducing additive is selected from the group comprising liquid water, steam, carbon, a metal carbonate, and mixtures of any two or more thereof.

16. The process of claim 15 , wherein the step of mixing the molten slag composition with a density-reducing additive comprises expanding the molten slag composition by injecting water and/or steam into the molten slag composition before the step of converting the molten slag composition into the solid slag granules.

17. The process of claim 13 , wherein the solid slag granules have internal voids.

18. The process of claim 1 , further comprising a step of coating at least some of the solid slag granules in a coating apparatus.

19. The process of claim 18 , wherein the coating step comprises coating the solid slag granules with a coating composition selected from the group comprising a resin composition and a ceramic composition.

20. The process of claim 19 , wherein at least one of the fractions produced by said sorting consists of said solid slag granules having an average sphericity of greater than 0.6,
wherein the coating composition comprises a resin composition, and
wherein the coating step is conducted after the step of sorting the solid slag granules by shape.

21. The process of claim 19 , wherein the coating composition comprises a resin composition, wherein the coating step comprises combining the resin composition with the solid slag granules, wherein the solid slag granules are heated to a temperature sufficient to melt the resin composition, and wherein the process further comprises tumbling the solid slag granules with the resin composition to produce polymer-coated slag granules.

22. The process of claim 19 , wherein the coating composition comprises a resin composition, and wherein the process further comprises curing the resin composition during or after the coating step.

23. The process of claim 22 , wherein the curing step comprises crosslinking of the resin composition with a crosslinking activator, wherein the crosslinking activator is included in the resin composition.

24. The process of claim 1 , further comprising the steps of:
(i) providing the molten slag composition in a metallurgical furnace;
(ii) withdrawing the molten slag composition from the metallurgical furnace;
(iii) while maintaining the molten slag composition at a sufficiently high temperature to prevent it from solidifying, transporting the molten slag composition to the dispersion apparatus.

25. The process of claim 24 , wherein a metallurgical composition of the molten slag composition remains constant after it is withdrawn from the metallurgical furnace and until it is converted to said solid slag granules.

26. The process of claim 1 , wherein the separator comprises a spiral separator.

27. The process of claim 1 , wherein the molten slag composition is substantially free of lime.

28. The process of claim 1 , wherein the molten slag composition is a non-ferrous slag.

Assignees

• Hatch Ltd

Inventors

• So Lai Chi
• Faucher Santiago

Classifications

• C22B7/04

  Working-up slag · CPC title

• C09K8/805 Primary

  Coated proppants · CPC title

• B01J23/78

  with alkali- or alkaline earth metals · CPC title

• C04B5/065

  Porous slag · CPC title

• C04B20/1029

  Macromolecular compounds · CPC title