Demetallized slag for abrasives and/or roofing granules and related methods

Patent metadata

Field	Value
Publication number	US-2024400873-A1
Application number	US-202418803306-A
Country	US
Kind code	A1
Filing date	Aug 13, 2024
Priority date	Apr 14, 2021
Publication date	Dec 5, 2024
Grant date	—

Abstract

Some methods for making a granular material comprise crushing demetallized slag particles with one or more crushers and screening the crushed demetallized slag particles with one or more screens to separate the demetallized slag particles into two or more fractions, the granular material comprising at least one of the fractions of the demetallized slag particles. Prior to the crushing, ones of the demetallized slag particles having a size that is less than or equal to 2 inches can account for at least 90% of the demetallized slag particles. An iron-compound content of the demetallized slag particles, by weight, can be less than or equal to 10%. Crushing and screening can be performed such that ones of the demetallized slag particles of the granular material having a size that is less than or equal to 1.25 mm account for at least 90% of the demetallized slag particles of the granular material.

First claim

1 . A method for making a granular material, the method comprising:
crushing demetallized steel slag particles with one or more crushers, wherein:
prior to the crushing, ones of the demetallized steel slag particles having a size that is less than or equal to 2 inches account for at least 90% of the demetallized steel slag particles; and
an iron-compound content of the demetallized steel slag particles, by weight, is less than or equal to 10%; and
screening the crushed demetallized steel slag particles with one or more screens to separate the demetallized steel slag particles into two or more fractions, the granular material comprising at least one of the fractions of the demetallized steel slag particles; wherein crushing and screening the demetallized steel slag particles is performed such that ones of the demetallized steel slag particles of the granular material having a size that is less than or equal to 1.25 mm account for at least 90% of the demetallized steel slag particles of the granular material.

2 . The method of claim 1 , wherein:
the one or more crushers comprise primary and secondary crushers; crushing the demetallized steel slag particles comprises crushing at least one of the fractions of the screened demetallized steel slag particles with the secondary crusher; and screening the demetallized steel slag particles comprises screening the demetallized steel slag particles crushed with the secondary crusher.

3 . The method of claim 1 , wherein each of the crusher(s) comprises a vertical shaft impact crusher.

4 . The method of claim 1 , wherein crushing and screening the demetallized steel slag particles is performed such that ones of the demetallized steel slag particles of the granular material having a size that is less than or equal to 0.90 mm account for at least 90% of the demetallized steel slag particles of the granular material.

5 . The method of claim 1 , comprising drying the demetallized steel slag particles.

6 . The method of claim 5 , wherein drying is performed such that less than or equal to 0.50% of the demetallized steel slag particles, by weight, comprises water.

7 . The method of claim 1 , comprising making the demetallized steel slag particles at least by:
removing one or more metallic components from furnace steel slag particles at least by passing the furnace steel slag particles through a demetallizer one or more times; crushing the furnace steel slag particles; and screening the crushed furnace steel slag particles with one or more screens to separate the crushed furnace steel slag particles into two or more fractions, the demetallized steel slag particles comprising at least one of the fractions.

8 . The method of claim 7 , wherein making the demetallized steel slag particles includes:
after passing the furnace steel slag particles through the demetallizer at least once, screening the furnace steel slag particles with one or more screens to separate the furnace steel slag particles into two or more fractions, wherein ones of the particles of a first one of the fractions having a size that is greater than or equal to 8 inches account for at least 90% of the particles of the first fraction; and removing the metallic component(s) includes passing the first fraction through the demetallizer.

9 . The method of claim 7 , wherein removing the metallic component(s) is performed with one or more magnets of the demetallizer.

10 . The method of claim 7 , wherein crushing the furnace slag is performed with a jaw crusher.

11 . The method of claim 7 , wherein the furnace steel slag particles comprises calcium oxide (CaO), iron (III) oxide (Fe 2 O 3 ), silicon dioxide (SiO 2 ), aluminum oxide (Al 2 O 3 ), magnesium oxide (MgO), and manganese (II) oxide (MnO).

12 . The method of claim 1 , wherein the demetallized steel slag particles comprise electric arc furnace steel slag.

13 . A plurality of steel slag particles, wherein:
ones of the steel slag particles having a size that is less than or equal to 1.25 mm and greater than or equal to 0.14 mm account for at least 90% of the steel slag particles; and an iron-compound content of the steel slag particles, by weight, is less than or equal to 10%.

14 . The steel slag particles of claim 13 , wherein ones of the steel slag particles having a size that is less than or equal to 0.90 mm and greater than or equal to 0.14 mm account for at least 90% of the steel slag particles.

15 . The steel slag particles of claim 13 , wherein the iron-compound content of the steel slag particles, by weight, is less than or equal to 5%.

16 . The steel slag particles of claim 13 , wherein the steel slag particles comprise electric arc furnace slag.

17 . The steel slag particles of claim 13 , wherein the steel slag particles comprise calcium oxide (CaO), silicon dioxide (SiO 2 ), aluminum oxide (Al 2 O 3 ), magnesium oxide (MgO), and manganese (II) oxide (MnO).

18 . The steel slag particles of claim 13 , wherein:
the steel slag particles are an abrasive blast media; and in a cleaning process in which the abrasive blast media is ejected at a pressure of 100 pounds per square inch from a No. 4 blast nozzle positioned 18 inches away from a surface of a hot rolled carbon steel substrate that includes mill scale, the abrasive blast media is configured clean the surface of the hot rolled carbon steel substrate at a cleaning rate of at least 135 square feet of the surface per hour (ft 2 /hr) such that the surface complies with SSPC-SP 10.

19 . The steel slag particles of claim 18 , wherein the cleaning rate is at least 140 ft 2 /hr.

20 . The steel slag particles of claim 18 , wherein in the cleaning process the abrasive blast media is ejected from the nozzle at a consumption rate of between 6 . 0 and 7 . 0 pounds per minute (lb/min).

Assignees

• Harsco Technologies LLC

Inventors

• Sandy Brandon
• Deangelo Dominic

Classifications

• C21D7/06

  by shot-peening or the like · CPC title

• B24C1/086

  Descaling; Removing coating films · CPC title

• B02C23/14

  with more than one separator · CPC title

• B02C23/12

  with return of oversize material to crushing or disintegrating zone · CPC title

• B02C13/14

  with vertical rotor shaft, e.g. combined with sifting devices · CPC title