WO1995023834A1

WO1995023834A1 - Coke for metallurgical uses

Info

Publication number: WO1995023834A1
Application number: PCT/GB1995/000465
Authority: WO
Inventors: Peter Robertson Pelling; Rodney Martin Sambrook
Original assignee: Dytech Corp Ltd
Current assignee: Dytech Corp Ltd
Priority date: 1994-03-03
Filing date: 1995-03-03
Publication date: 1995-09-08
Anticipated expiration: 1996-09-03
Also published as: GB2287037B; AU1853095A; GB9404108D0; GB2287037A

Abstract

Spent catalyst is added to coal and the mixture converted to coke in a coke oven.

Description

COKE FOR METALLURGICAL USES

The invention relates to the production of coke useful in the manufacture of metallurgical products such as steel or the like. The invention concerns the inclusion of a waste material together with the coal from which coke is manufactured, which waste material is otherwise costly and inconvenient to treat.

The recycling or disposal of metal-containing solid wastes from catalytic processes is difficult and costly. The wastes contain a complex mixture of materials, the contained metals typically being nickel, vanadium, cobalt, molybdenum, tungsten, tin; and the like. The catalytically active material will typically be presented on a carrier, such as alumina, carbon, silica, zeolite; or the like. The waste material will also contain significant residues from the catalytic process such as carbonaceous material and sulphur. It has now been realised that if these waste materials are used with the coal in the manufacture of coke, the waste material is effectively treated and the coke can then be used in circumstances in which the presence of the catalytically active metals is useful.

According to the invention in one aspect there is provided a method of providing a metal-containing coke for use in the production of steel or the like; the method comprising feeding coal and spent metal catalyst to a coke oven and converting the coal to coke thereby to form a coke containing the catalytically active metal.

The spent catalyst material may be added to the oven alongside the coal or the two may be preblended in appropriate proportions. Typically the spent catalyst will be present in a low concentration to minimise the risk of any damage to the coke oven or carry over of unacceptable level of materials into the metallurgical product to be formed. The concentration is preferably up to 2% by weight, preferably less.

Usually the spent catalyst is used directly or it may be pretreated to adapt it better for the coking process.

The grades of coal used are selected according to the requirements of the finished coke product. The coal may be partly replaced by another source of carbonaceous material, e.g. tar, pitch; or the like.

When the spent catalyst is heated in a coke oven alongside the coal, the catalyst support and the contained metal or metal salts or oxides will remain and be included in the formed coke. The carbonaceous material can be converted into coke or become part of the coke oven gas (which at some installations can be used to heat the coke ovens). The sulphur will join other sulphur released from the coal and will be treated in the usual way and some sulphur may remain in the coke.

The coke oven may be of any appropriate type, having a basic or an acidic lining and in which the coal is heated up to about 1200°C or even higher, e.g. up to 1800°C. Other additives may be present, in known manner.

A coke product of the invention can be used in the manufacture of steel. For example, it can be a reactive coke to be added to the blast furnace charge so contributing valuable alloying elements. A coke may also be used in electrometallurgical furnaces; foundry cupolas; carbide furnaces; and the like. The non-metallic fractions will be included in the steelworks slag.

The invention is capable of uses beyond those specifically mentioned. For example, the coke is useful in the metallurgy of iron, zinc, tin, and other metals. In order that the invention may be well understood it will now be described by way of illustration with reference to the following examples.

Example I

Black pellets of spent catalyst comprising a mixture of carbon, hydrocarbons, sulphur, alumina, nickel, molybdenum and cobalt were added to a coal tar mix in a proportion of less than 2% by weight. The resultant blend was converted to coke in a coke oven. The formed coke was added to a blast furnace charge.

Example II

Granules of spent catalyst comprising a mixture of carbon, hydrocarbons, aluminosilicate, nickel and vanadium, were treated in the manner of Example I.

Claims

1. A method of providing a metal-containing coke for use in the production of steel or the like; the method comprising feeding coal and spent metal catalyst to a coke oven and converting the coal to coke thereby to form a coke containing the catalytically active metal.

2. A method according to Claim 1 , including heating the coal up to 1200°C.

3. A method according to Claim 1 , wherein the coke oven has a basic lining.

4. A method according to Claim 1 , wherein the coke oven has an acidic lining.

5. A method according to any preceding Claim, wherein the coal is at least partly replaced by another carbonaceous material.

6. A method according to any preceding Claim, wherein the proportion of spent catalyst is below 2% by weight of the mixture to be converted.

7. A method according to any preceding Claim, including the subsequent step of using the coke as an additive in a metallurgical process.

8. A method according to Claim 7, wherein the coke is added to a blast furnace and used in the manufacture of steel.