US1233144A - Smelting process. - Google Patents

Description

NILS TESTRUP, OF LONDON, ENGLAND, AND THOMIAS RIG-BY, 0F DUMFRIES, SCOTLAND, ASSIGNORS TO VTETCARBONIZING LIMITED, OF LONDON, ENGLAND.

SMELTING PROCESS.

Specification of Letters Patent.

Patented July 10, 1917.

No Drawing. Original application filed December 6, 1911, Serial No. 664,144. Divided and. this application filed February 9, 1914. Serial No. 817,637.

To all whom it may concern:

Be it known that we, NlLS Tns'rnur, a subject of the King of Great Britain and Ireland, and residing at 3 Dean Farrar st., London, S. W., England, and THOMAS Riser, a subject of the King of Great Britain and Ireland, and residing at 61 Lor'eburn street, Dumfries, Scotland, have invented a certain new and useful Smelting Process, of which the following is a specification.

This invention relates to the smelting ofmetalliferous ores, such as iron ore, its obj ect being to provide an improved method of utilizing peat as a reducing agent. Hitherto in using peat for such a purpose, the chief difficulties have been the obtaining of a con tinuous supply of dry peat, since this was dependent upon weather conditions, and preventing choking of the furnace as a result of the crumbly nature of the material when coked.

It has been found that these disadvantages are overcome by the use of peat which has been subjected to the Ekenberg process, known as wet carbonization, which consists in heating the peat under pressure suflicient to prevent ebullition to a temperature of about 180 (1, until its water binding properties are destroyed. Having thus been treated, the peat can readily be de-wa-tered by filter-pressing, which produces press cakes suitable for use as the reducing agent, when directly added to the furnace charge, or after having been further dried and converted into briquets, which are then added to the charge.

In this way, preliminary coking hitherto usual is rendered unnecessary, as it takes place in the furnace itself, while the hard" ness and crushing strength of the coke thus produced from the filter press cakes is equal to that of the best wood charcoal, and that from the briquets equal to the crushing strength of the best smelting coke, with the result that such coke is able to carry the weight of the charge.

The present invention therefore consists in the application of wet carbonized peat as a reducing agent for the smelting of metalliferous ores, in which the material is used in the form of press cakes or briquets, which are added to the furnace charge.

In carrying the invention into effect, as applied to smelting iron ore in a shaft furnace of the type described in Patent No. 1106166, the peat is heated to a tei'nperature of about 180 0., in a carbonizer of the wellknown concentric tubular type, under pressure suflicient to prevent ebullition, until the water binding properties of the peat have been destroyed, whereupon the mate rial is subjected to filter pressing, which results in the production of filter press cakes having a water content of about 70 per cent. To the furnace charge, consisting of iron ore and limestone, the filter press cakes are added, either as such, or as briquets formed after drying the material until its water con tent is about 5 per cent. In gradually de scending therethrough the peat becomes coked by the hot uprising gases from the hot zone, while the products of destructive distillation pass off with the shaft gases at the top of the shaft, and are treated for recovery of nitrogen and tar, preferably by introducing the gases into the foul main of an ammonia recovery gas producer if, as often occurs, such is used for power, and fuel gas generation in the plant and which latter may conveniently also be supplied with peat press cake, briquets, or a mixture thereof.

An intimate mixture of the furnace and producer gases resultsin such an event and the combustible value of the latter is consequently enhanced.

e have observed that the te nperature of coking the material in question is less important as affecting the strength of the product than the pressure employed in forming the cake or briquet, and consequently low coking temperatures such as prevail in the shaft can be used, and a high nitrogen recovery obtained.

Having now described our invention what we claim as new and desire to secure by Letters Patent is 1. A method of smelting metalliferous ores by means of peat blocks, according to which said blocks are finally rendered suitable for use as a reducing agent by the action of the waste heat of the furnace after their insertion therein in admixture with the ore as part of the furnace charge.

2. A method of smelting metalliferous ores by means of peat blocks, according to which said blocks are formed of peat which has been dewatered after heat treatment adapted to destroy its water binding properties, and are finally rendered suitable for use as a reducing agent by the action of the Waste heat of the furnace after their insertion therein in admixture with the ore as part of the furnace charge. 7

3. A- method of smelting metalliferous ores by means of peat blocks, according to Which said blocks are formed of peat which has been subjected to a temperature of 180 C. under pressure sufficient to prevent ebullition and then had its liberated water removed by filter pressing, and are finally rendered suitable for use as a reducing agent by theaction of the Waste heat'of the furnace after their insertion therein in admixture with the ore as part of the furnace charge.

4:. A 'method of smelting metalliferous ores by means of peat, consisting in heating the peat to a high temperature under pressure sufficient to prevent ebullition, filter pressing the material to remove Water liberated by the heating, further drying the material, consolidating the same into bri- Gopies of this pat ent maybe obtained for quets and admixing said briquets with the ore as part of the furnace charge so that the peat is finally rendered suitable for use as a reducing agent by the Waste heat of the smelting process.

5. A method of smelting metalliferous ores by means of peat, consistin in subjecting peat to heat treatment adapted to set free the Water contained therein, removing said Water as by filter pressing, forming the solid material into blocks and admixing said blocks with the ore as part of the furnace charge so that the peat is finally rendered suitable for use as a reducing agent by the Waste heat of the smelting process.

In testimony whereof We have hereunto signed our names to this specification in the presence of two subscribing Witnesses.

NILS TESTRU P.

T. RIGBY. Witnesses:

Rom. J. NORTON, T. ZACHAN.

five cents each, by addressing the Commissioner of Patents. Washington, I). G.