GB2145104A - Method and material for treating coke oven doors and other metal objects - Google Patents

Abstract

A material that is essentially an acidified, graphite-free aqueous solution of a soluble silicate and a soluble resin (e.g. a carboxy polymethylene resin) is described that will form a lubricating adhesive coating on coke oven doors and/or jambs to prevent leakage of tar and other coke by-products and the resultant build up as heretofore common in the art and the resultant inability of maintaining a sealing relation between the doors and jambs. Other applications include treatment of forging dies and ingot moulds.

Description

SPECIFICATION Method and material for treating metal objects This invention relates to a method and material for treating metal objects which are to be subjected to high temperatures, such as coke ovens and the doors thereon to provide for the sealing of the doors with respect to the jambs during the coking operation.

Coke ovens are provided at their opposite ends with self-sealing doors that depend on a metal to metal contact between the door and the continuous machined surface cast iron jamb.

In a typical example the sealing edge of the door is carried by a flexible frame and the door assembly includes a powerful spring between the door and the locking bar to force the sealing edge against the metal door jamb to prevent the escape of volatile products from the coke oven. Such door and jamb assemblies on the coke side and pusher side of the coke oven commonly fail to maintain a sealing metal to metal relation and tar and other byproducts produced during the coking operation escape and build up between the door and jambs and must be manually removed each time the doors are removed and repositioned when the coke is pushed from the oven.The tar and by-products build up deposits which are difficult to remove and the removal is time consuming so that frequently the doors are repositioned and the desirable sealing relation to effect an efficient coking operation is adversely affected.

In one aspect, the present invention relates to a material capable of forming a penetrating and lubricating adhesive coating on the sealing edges of the doors and jambs that is not affected by the heat of the coking operation and to which tar and other by-products will not adhere with the result that the sealing edges of the doors and jambs which are engaged thereby remain clean and free of tar and other by-product build-up and can effectively seal the coke oven.

The prior art comprises my U.S.Patents Nos. 4,187,334 and 4,187,335 issued February 5, 1980.

According to the invention there is provided a normally liquid suspension material suitable for forming sealing and lubricating adhesive coatings on metal objects which are to be subjected to high temperatures and comprising in the absence of graphite from about 34% to 75% of an aqueous solution of a silicon compound, the solution containing from 30 to 50% by weight of the silicon compound, from about 2% to 10% of concentrated hydrochloric acid having a purity of at least about 90% by weight, and from 20% to 64% of an aqueous solution of a resin, the solution containing from 1 % to 10% by weight of the resin.

The solution of the silicon compound preferably contains from 35% to 45%, most preferably about 40%, of the silicon compound.

The aqueous resin solution may be present in an amount of at least 26%, for example 33%, by weight.

The water soluble resin may be a carboxylated polymer, for example carboxy polymethylene, or the like, carboxylic acids, either C00H or C02H and/or composed of a carboxyl group and a hydroxyl group, carboxyl; oxatyl, carboxy, the acidic COOH group. The soluble silicate provides an effective lubricating and adhesive coating material when applied to the coke oven doors and jambs as by spraying the same thereon which will seal the same and prevent objectional emissions.

The resin may be a carboxy polymethylene powder having a specific gravity of 1.41 and a bulk density of 1 3 Ibs. per cubic foot. It is available as "CARBOPOL" from B.F.Goodrich Chemical Co. and low concentrations mixed with water as herein disclosed produce a thin gel-like liquid with penetrating and adhesive qualities.

In using the material disclosed herein the process involves mixing the materials and then applying the same, for example by spraying using any suitable spraying equipment on cleaned metal surfaces of the metal objects such as coke oven doors and jambs to be treated. One or more coatings may be applied as necessary to build up a smooth unbroken surface of the material in and on the metal parts being treated and the material may be applied to the metal surfaces while they are either hot or cold.

The ability of the material to be applied to the hot metal surfaces is particularly advantageous in a coke oven operation as the doors are removed from the ovens to permit a pusher to move the coke from the ovens while the ovens themselves are maintained at or near coking temperatures.

Those skilled in the art will observe that the heretofore necessary manual cleaning of the doors and door jambs frequently required motorized buggies and similar mechanical equipment and the time of such cleaning is eliminated through the use of the material hereinbefore disclosed.

It will also be observed that the production of metallurgical coke is improved and stabilized by providing for the effective sealing of the coke oven doors made possible with the material herein disclosed.

It has been determined that other applications and uses of the material disclosed herein are possible and such may include the treating of forging dies in the hot forging of metals and the treatment of various metal handling and processing equipment wherein the surface condition of the metal treating equipment is desirably maintained in a smooth condition resisting adhesion or contaminates thereto.

Additionally ingot moulds are advantageously treated with the material of the invention as such treatment expedites the stripping of ingots from the moulds. The following specific example of the material has been found satisfactory for the treatment of coke oven doors and jambs and like metal surfaces.

EXAMPLE Substantially 67% by weight aqueous solution of a water soluble silicate such as sodium silicate wherein the silicate is present at about 40% by weight of the solution, substantially 7% by weight concentrated hydrochloric acid of substantially 90% purity, substantially 18% by weight water, substantially 8% by weight of a water soluble carboxy polymethylene polymer resin as a powder wherein the resin is present at substantially 8% by weight of the solution so as to form a foam upon application to the coke oven doors and jambs.

It will be observed that the invention disclosed in this application avoids the use of graphite particles necessary to the inventions disclosed in GB-A-2055306 and GB-A2055624. Emphasis is now made of the material comprising primarily an aqueous solution of a soluble silicate such as sodium silicate or the like which will form a closely adhering filling and lubricating foam-like material upon application to the coke oven doors and jambs and thus enable the same to be effectively sealed during operation so as to prevent emissions of coal, tar and other coke by-products and the resultant build up as heretofore common in the art with the resulting inability of maintaining a sealing relation between the doors and jambs and the escape of the objectionable pollutants into the atmosphere.

The example in this application discloses the use of the material of the liquid carrier comprising substantially 67% by weight of an aqueous solution of a water soluble silicate such as sodium silicate as set forth in the specification.

The reference to soluble silicates is intended to include any of the widely occurring compounds containing silicon, oxygen, and one or more metals with or without hydrogen. The silicon and oxygen may combine with organic groups to form silicate esters, most rocks, except limestone and dolomite, and many mineral compounds are silicates. Typical natural silicates are gem stones, except diamonds, beryl, asbestos, talc, clays, feldspar, mica.

Portland cement contains a high percentage of calcium silicates.

Since the best known of the synthetic "soluble" silicates is sodium silicate (water glass) it has been used as the preferred example in this disclosure. It has been determined that it is also possible to prepare a desirable sealing, coating, adhesive material incorporating silicic acid, which is a hydrated silica. It has also been determined that silicone, which may be any of a large group of siloxane polymers based on a structure consisting of alternate silicon and oxygen atoms with various organic radicals attached to the silicon may be used.

A commercial example of such material is "SILICLAD", which is a trademark for a water soluble silicon concentrate sold by Clay Adams, Inc.

Although the embodiments of the present invention have been limited as described hereinbefore, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the invention.

Claims (11)

1. A normally liquid suspension material suitable for forming sealing and lubricating adhesive coatings on metal objects which are to be subjected to high temperatures and comprising in the absence of graphite particles from about 34% to 75% of an aqueous solution of a silicon compound, the solution containing from 30 to 50% by weight of the silicon compound, from about 2% to 10% of concentrated hydrochloric acid having a purity of at least about 90% by weight, and from 20% to 64% of an aqueous solution of a resin, the solution containing from 1 % to 10% by weight of the resin.

2. A material according to claim 1, in which the solution of the silicon compound contains from 35% to 45% by weight of the silicon compound.

3. A material according to claim 2, in which the solution of the silicon compound contains about 40% by weight of the silicon compound.

4. A material according to any preceding claim, in which the silicon compound is silicic acid, a silicate or a siloxane.

5. A material according to claim 4, in which the silicon compound is sodium silicate.

6. A material according to any preceding claim, in which the resin is a carboxylated polymer.

7. A material according to claim 6, in which the resin is a carboxy polymethylene resin.

8. A material according to any preceding claim, containing at least 26% by weight of said resin solution.

9. A material according to claim 8, containing at least 33% by weight of said resin solution.

10. A material suitable for forming sealing and lubricating adhesive coatings on metal objects, substantially as hereinbefore described with reference to the Example.

11. A method of forming sealing and lubricating adhesive coatings on metal objects, which comprises applying to the object a material according to any preceding claim.

1 2. A method of treating coke oven doors and/or jambs, which comprises applying to the doors and/or jambs a composition according to any one of claims 1 to 10.