# US 2014/0190648 A1 · Method for curing cold-box foundry shape with gaseous catalyst

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- Number: US 2014/0190648 A1
- Document ID: US20140190648A1
- Status: Published application
- Kind: A1
- Application number: 14/232,343
- Filed: 2012-07-19
- Published: 2014-07-10
- Earliest claimed: 2011-07-19
- Assignees: ASK Chemicals GmbH
- Inventors: Xianping Wang; Douglas J. Desmit; Joerg Kroker
- Web page: https://patentgrep.com/patent/US20140190648A1

## CPC

- B22C 9/123: {Gas-hardening}
- B22C 1/162: {use of a gaseous treating agent for hardening the binder}
- B22C 9/02: Sand moulds or like moulds for shaped castings
- B22C: FOUNDRY MOULDING (moulding refractory materials in general B28B)

## Abstract

A “cold box” process for forming a foundry shape by curing a binder in a foundry mix operates by sequentially introducing a first vaporous curing catalyst to a pattern containing the formed foundry mix, followed by introducing at least a second vaporous curing catalyst. By arranging the amounts of the respective vaporous curing catalysts and the contact times, as well as by using the less active vaporous curing catalyst first, the total amount of curing catalyst used to effect the cure is reduced. Carrier gas may be used with the respective vaporous curing catalysts. Typically, the vaporous curing catalysts are tertiary amines having between three and six carbon atoms.

## Claims

### Claim 1

A “cold box” process for forming a foundry shape, comprising the steps of:
introducing a foundry mix into a pattern to form the foundry shape, the foundry mix comprising a foundry aggregate and an uncured binder;
contacting, in a sequential manner, the formed foundry shape with a first and at least a second vaporous curing catalyst, each curing catalyst capable of curing the formed foundry shape, until the formed foundry shape is sufficiently cured to be handleable; and
removing the formed and cured foundry shape from the pattern.

### Claim 2 (depends on 1)

The process of claim 1, wherein:
the sequential contacting step comprises the substeps of:
contacting the foundry shape with a gas comprising the first vaporous curing catalyst, with or without a catalytically-inert carrier gas and substantially devoid of the second vaporous curing catalyst, resulting in a partially-cured foundry shape; and
contacting the partially-cured foundry shape with a gas comprising the second vaporous curing catalyst, with or without a catalytically-inert carrier gas.

### Claim 3 (depends on 2)

The process of claim 2, wherein:
the first and second vaporous curing catalysts are selected such that, for the binder, the first vaporous curing catalyst is less active than the second vaporous curing catalyst.

### Claim 4 (depends on 1)

The process of claim 1, wherein:
each of the first and second vaporous curing catalysts is a tertiary amine.

### Claim 5 (depends on 4)

The process of claim 4, wherein:
each of the first and second vaporous curing catalysts has between three and six carbon atoms.

### Claim 6 (depends on 5)

The process of claim 5, wherein:
the first vaporous curing catalyst is triethyl amine.

### Claim 7 (depends on 5)

The process of claim 5, wherein:
the second vaporous curing catalyst is dimethylisopropylamine.

### Claim 8 (depends on 5)

The process of claim 5, wherein:
the second vaporous curing catalyst is dimethyl ethyl amine.

### Claim 9 (depends on 5)

The process of claim 5, wherein:
the second vaporous curing catalyst is dimethyl propyl amine.

### Claim 10 (depends on 1)

The process of claim 1, wherein the foundry mix comprises a major amount of the foundry aggregate.

### Claim 11

An apparatus for forming a cured foundry shape from a foundry mix comprising a foundry aggregate and a binder, by way of a “cold box” process, the apparatus comprising:
a core box for containing the foundry shape being formed, the core box having an inlet and a outlet, the inlet and outlet arranged relative to each other to facilitate contact between the binder and a vaporous curing catalyst;
an apparatus for providing a first and a second curing catalyst in a vaporous state, the apparatus comprising:
a first chamber for vaporizing the first catalyst, the first chamber connected to the core box inlet;
a second chamber for vaporizing the second catalyst, connected to the core box through the first chamber; and
a source of a catalytically-inert carrier gas, directly connected to each of the first and second chambers, to propel the respective vaporous curing catalysts through the core box.

### Claim 12 (depends on 11)

The apparatus of claim 11, further comprising:
an apparatus for recovering the vaporous curing catalyst, connected to the outlet of the core box.

### Claim 13 (depends on 12)

The apparatus of claim 12 wherein:
the apparatus for recovering the vaporous curing catalyst comprises apparatus to separate the respective first and second curing catalysts.

### Claim 14 (depends on 1)

The process of claim 1, wherein:
the first and second vaporous curing catalysts are selected such that, for the binder, the first vaporous curing catalyst is less active than the second vaporous curing catalyst.

### Claim 15 (depends on 6)

The process of claim 6, wherein:
the second vaporous curing catalyst is dimethylisopropylamine.

### Claim 16 (depends on 6)

The process of claim 6, wherein:
the second vaporous curing catalyst is dimethyl ethyl amine.

### Claim 17 (depends on 6)

The process of claim 6, wherein:
the second vaporous curing catalyst is dimethyl propyl amine.

### Claim 18 (depends on 3)

The process of claim 3, wherein:
each of the first and second vaporous curing catalysts is a tertiary amine.

### Claim 19 (depends on 14)

The process of claim 14, wherein:
each of the first and second vaporous curing catalysts is a tertiary amine.

### Claim 20

A “cold box” process for forming a foundry shape, comprising the steps of:
introducing a foundry mix into a pattern to form the foundry shape, the foundry mix comprising a major amount of a foundry aggregate and an uncured binder;
contacting, in a sequential manner, the formed foundry shape with a first and at least a second vaporous curing catalyst, each vaporous curing catalyst being a tertiary amine with between three and six carbon atoms and capable of curing the formed foundry shape, until the formed foundry shape is sufficiently cured to be handleable; and
removing the formed and cured foundry shape from the pattern.