# US 2020/0399725 A1 · Cast iron inoculant and method for production of cast iron inoculant

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- Number: US 2020/0399725 A1
- Document ID: US20200399725A1
- Status: Published application
- Kind: A1
- Application number: 16/957,286
- Filed: 2018-12-21
- Published: 2020-12-24
- Earliest claimed: 2017-12-29
- Assignees: Elkem ASA
- Applicants: Elkem Asa
- Inventors: Oddvar KNUSTAD
- Web page: https://patentgrep.com/patent/US20200399725A1

## CPC

- C21C 1/105: {Nodularising additive agents}
- C22C 33/08: Making cast-iron alloys
- C21C: PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C22C: ALLOYS (treatment of alloys C21D, C22F)

## Abstract

An inoculant for the manufacture of cast iron with spheroidal graphite is disclosed, the inoculant has a particulate ferrosilicon alloy having between 40 and 80% by weight of Si; 0.02-8% by weight of Ca; 0-5% by weight of Sr; 0-12% by weight of Ba; 0-15% by weight of rare earth metal; 0-5% by weight of Mg; 0.05-5% by weight of Al; 0-10% by weight of Mn; 0-10% by weight of Ti; 0-10 by weight of Zr; the balance being Fe and incidental impurities in the ordinary amount, wherein the inoculant additionally contains, by weight, based on the total weight of inoculant: 0.1 to 15% of particulate Sb2S3, and optionally between 0.1 and 15% of particulate Bi2O3, and/or between 0.1 and 15% of particulate Sb2O3, and/or between 0.1 and 15% of particulate Bi2S3, and/or between 0.1 and 5% of one or more of particulate Fe3O4, Fe2O3, FeO, or a mixture thereof, and/or between 0.1 and 5% of one or more of particulate FeS, FeS2, Fe3S4, or a mixture thereof, a method for producing such inoculant and use of such inoculant.

## Claims

### Claim 1

An inoculant for the manufacture of cast iron with spheroidal graphite, wherein said inoculant comprises
a particulate ferrosilicon alloy consisting of between about 40 to 80% by weight Si;
0.02-10% by weight Ca;
0-15% by weight rare earth metal;
0-5% by weight Al;
0-5% by weight Sr;
0-5% by weight Mg;
0-12% by weight Ba;
0-10% by weight Zr;
0-10% by weight Ti;
0-10% by weight Mn;
wherein at least one, or the sum, of elements Ba, Sr, Zr, Mn, or Ti is (are) present in an amount of at least 0.05% by weight, the balance being Fe and incidental impurities in the ordinary amount,
wherein said inoculant additionally contains, by weight, based on the total weight of inoculant: 0.1 to 15% by weight of particulate Sb2O3.

### Claim 2 (depends on 1)

The inoculant according to claim 1, wherein the ferrosilicon alloy comprises between 45 and 60% by weight of Si.

### Claim 3 (depends on 1)

The inoculant according to claim 1, wherein the ferrosilicon alloy comprises between 60 and 80% by weight of Si.

### Claim 4 (depends on 1)

The inoculant according to claim 1, wherein the rare earth metals include Ce, La, Y and/or mischmetal.

### Claim 5 (depends on 1)

The inoculant according to claim 1, wherein the inoculant comprises 0.5 to 10% by weight of particulate Sb2O3.

### Claim 6 (depends on 1)

The inoculant according to claim 1, wherein the inoculant is in the form of a blend or a physical mixture of the particulate ferrosilicon alloy and the particulate Sb2O3.

### Claim 7 (depends on 1)

The inoculant according to claim 1, wherein the particulate Sb2O3 is present as a coating compound on the particulate ferrosilicon alloy.

### Claim 8 (depends on 1)

The inoculant according to claim 1, wherein the inoculant is in the form of agglomerates or briquettes made from a mixture of the particulate ferrosilicon alloy and the particulate Sb2O3.

### Claim 9 (depends on 1)

The inoculant according to claim 1, wherein the particulate ferrosilicon based alloy and the particulate Sb2O3 is added separately but simultaneously to liquid cast iron.

### Claim 10 (depends on 1)

A method for producing an inoculant according to claim 1, the method comprises:
providing a particulate base alloy consisting of
between 40 to 80% by weight of Si;
0.02 to 10% by weight Ca;
0-15% by weight rare earth metal;
0-5% by weight Al;
0-5% by weight Sr;
0-5% by weight Mg;
0-12% by weight Ba;
0-10% by weight Zr;
0-10% by weight Ti;
0-10% by weight Mn;
wherein at least one, or the sum, of elements Ba, Sr, Zr, Mn, or Ti is (are) present in an amount of at least 0.05% by weight, the balance being Fe and incidental impurities in the ordinary amount, and adding to the said particulate base alloy 0.1 to 15% by weight particulate Sb2O3, to produce said inoculant.

### Claim 11 (depends on 10)

A The method according to claim 10, wherein the particulate Sb2O3 is mixed or blended with the particulate base alloy.

### Claim 12 (depends on 1)

A method for manufacturing of cast iron with spheroidal graphite, by adding the inoculant according to claim 1 to the cast iron melt prior to casting, simultaneously to casting or as an in-mould inoculant.

### Claim 13 (depends on 12)

The method according to claim 12, wherein the particulate ferrosilicon based alloy and the particulate Sb2O3 is added as a mechanical mixture or a blend to the cast iron melt.

### Claim 14 (depends on 12)

The method according to claim 12, wherein the particulate ferrosilicon based alloy and the particulate Sb2O3 is added separately but simultaneously to the cast iron melt.