US1545620A - Process of producing coke - Google Patents

Description

' stantial portion of the organic sulphur never- Patented July 14, 1925.

UNITED STATES PATENT OFFICE.

WALTER EDWIN TRENT, OF WASHINGTON, DISTRICT OF COLUMBIA.

PROCESS OF PRODUCING COKE.

No Drawing.

have invented certain new and useful Improveme'nts in Processes of Producing Coke, of which the following is a specification.

The invention relates to a process for producing metallurgical coke in which the organic sulphur originally contained in the coal is dissolved in the s a'g when the coke is consumed in a blast furnace. I

In the past, efiorts have been made to keep the sulphur out of iron made in blast furnaces by mixing with the coal undergoing a coking treatment, a substance such as limestone. The coarsely ground coal, when mixed with limestone and subjected to a coking action, causes some of the sulphur to combine with the limestone, producing in the coke calcium sulphide, but this reaction is not entlrely satisfactory for. the reason that a very subcomes in contact with the limestone in view of the size of the coal, and therefore a substantial part of the sulphur comes in contact with the pig iron in the blast furnace.

rises a process portion of the from becoming The present invention com by which the most substantia organic sulphur is prevented associated with the iron.- In accordance with this invention very finely ground particles of limestone or lime hydrate or an equivalent substance mixed with Oll, are unzformly distributed or mixed with finely ground coal particles forming a plastic mass in which there is a close association between the sulphur and the limestone. On account of the uniformit of the mixture when the mass is coked tie sulphur of the coal is taken up as calcium sulphide and is dissolved in the slag and discharged from the furnace during a blast furnace operation, thereby preventing deleterious quantities of sulphur from becoming associated with the IIOIl.

In a more specific aspect, the invention comprises a process wherein coal is first finely pulverized, and then preferabl saturated with water. Finely pulverize limestone is mixed withhydrocarbon oil, and these substances then commingle with the water saturated or suspended coal particles. The agitation causes the oil, limestone and carbon content of the coal to intimately Application filed October 6, 1923. Serial No. 667,046.

associate and form a homogeneous plastic mass, excluding water and a substantial portlon of the wet impurities originally contalned in the coal which have no affinity for the oil after once receiving a coating or saturation with water, the specific reaction which occurs having been fully described and broadly claimed in my Patent, No. 1420164 The product produced consists of a. plastlc mass in which the fine particles of limestone are uniformly distributed throughout the mass so that the limestone particles are in very close association with the organic sulphur whereby the coking of the mass causes the sulphur to be largely taken up as calcium sulphide. This coking also causes some of the sulphur to be dis charged from the coal as a vapor ,in the form of sulphur gases. When the coke thus produced is used in a blast furnace the calcium sulphide is absorbed in the slag and dis- 'charged from the furnace, thereby preventing the deleterious sulphur from coming in contact with the pig iron.

In carrying out my process, I preferably take a bltuminous coal of any des1red grade and reduce this coal bya wet grinding to a fineness suflicient to pass through a screen havlng 1.00 meshes perlinear inch. I then lacethis coal in water suspension or at east wet the coal with water. A hydrocarbon oil-which may be fuel oil, gas oil, crude oil or the like, is mixed with limestone which is alsovery finely ground, preferably to the fineness equal to the fineness of the coal. .The oil should be in the proportion of about one-fourth of the coal, or that i's to say, with four tones of coal I preferably use about one ton of oil. The quantity of limestone added maybe from ten'to twelve percent of the oil by weight, although thls will vary considerably, depending upon the sulphur content of coal used and also the type of oil, because many "oils contain a sulphur content, andit is an object to re- 1n the body of oil so as to be uniformly distributed in said oil. The oil with the suspended particles of limestone is then introduced to an agitatingvessel containing the water suspended coal. These substances are at this time mostthoroughly agitated,

the oil serving to coat or film the coal and to been coated with oil, it has no afiinity carry with it the suspended particles of limestone. Sufficient agitation will cause the oil and coal with the limestone to agglomerate or amalgamate in dense plastic masses of a consistency resembling mortar, or in marble-like agglomerates. Ash forming substances, iron sulphides, etc., originally contained in the coal detached by the fine grinding thereof are excluded from said amalgamated masses together with a greater portion of thewater so that the amalgamated mass consists largely of coal oil, limestone and a small quantity of water. The coal impurities are rejected because having once been saturated in water, they have no aflinity for the oil. It is to be observed, however, that the limestone having once been saturated with the oil and after havinfg once or the water. and therefore remains with the oil and coal while the ash formingsubstances are eliminated.

The thorough agitation of these materials, as before stated, results in formation of the amalgamated substances in which the fine particles of lime have been carried by the oil into intimate contact with the coal and becomes uniformly distributed throughout the masses. The lime particles being 1n di rect or intimate contact with the various individual coalparticles, and also with the oil, it is therefore closely associated with the organic sulphur contained in the coal particles and also with the sulphur of the o1 When a mass of the amalgamated material is introduced to the coke oven and subjected to a temperature, some of the organic sul phur leaves as sulphur gases, but the predominating ortion thereof'chemically combines with t e limestone and forms in the coke calcium sulphide. Because of the in timate mixture of-the limestone with the coal and oil, substantially all of this sulphur is caused to unite with the limestone producing calcium sulphide. The coke thus produced when used in a blast furnace in the reduction of iron ores, causes a release of the calcium sulphide which is absorbed in the slag in the furnace, and is discharged therefrom without contact with the pi iron. 7

The iron thus produced, therefore, is not subjected toany substantial quantity of sulphur and for this reason an improved procluct can be obtained.

As a specific example of the proportions which I have successfully used in carrying out my process I find that with a coal containing from 1 to 1.5 percent sulphur remainin therein, that suflicient limestone should e added to the oil to represent from 1 to 3 percent of calcium in the final coke. Generally one ton of the fuel oil is used with approximately four tons of coal. Before this oil is added to the coal, pulverized limestone of an impal able fineness, pref erably equal to the neness of the coal, which may be from 100 to 200 meshes per 'inch, is added to the oil, and if the coal is not exceedingly high in sulphur, this quantity of limestone would be sufiicient to perform the reaction herein described. As previously stated, however, the relative quantities may vary, depending upon the amount of sulphur'the coal contains, and also on the t pe of coal used, but with the usual-rune coking bituminous coals, the examples cessful.

The rocess may be applied to oils that are big in sulphur. for'the purpose of desulphurizing the oil'by first making the oil lime coal mixture then distilling out the oil as gases and condensible vapors.

Having thus described my invention what I claim is:

1. The herein described process, which given above have proven succonsists in mixing pulverized coal with 1 water, in adding pulverized lime to a liquid the pulverized coal to form an amalgamated mass.

2. The herein described process, which consists in introducing to hydrocarbon oils a quantity of finely pulverized limestone, and in intimately mixing said limestone with finely reduced coal to form an amalgamated mass of a plastic consistency.

'3. The herein described process, which consists in mixing a substance possessing the properties of lime with hydrocarbon oil, and in then agitating such materials with finely reduced coal to form a" plastic mass. Y Y

4. A process of the character described, consisting in comm-ingling hydrocarbon oil with finely pulverized coal having a sulphur content to form a substantially plastic mass, and in incorporating with the hydrocarbon oil an agent adapted to be thoroughly distributed throughout the plastic mass of coal and oil to intimately contact with the sulphur content of the coal and possessing the properties of forming with said sulphiu' when the mass is heated calcium sulphide.

- 5. A purifying proces, consisting in intimately mixing finely pulverized'coal containing a sulphur content and a hydrocarform with said sulphur when the mass is subjected to a coking. temperature calcium sulphide.

7. A purifying process, which consists in mixing comminuted coal,' hydrocarbon oil and reagent to form a homogeneous mass and to bring said reagent into intimate contact with the sulphur contained in the coal to remove said sulphur when the mass is subjected to acoking temperature.

8. A purifying process, which consists in mixing comminuted; coal, hydrocarbon oil and reagent to form a homogeneous mass and to bring said agent into intimate contact with the sulphur contained in the coal to remove said sulphur when the ma& is subjected to a coking temperature as calcium and sulphide compounds.

9. The herein described process consistaceous material. and oxides of the calcium group to form a homogeneous substantially plastic mass.

10..The herein described process which consists in mixing comminuted coal, a mineraloil, and oxides of the calcium group to form a homogeneous mass with said materials distributed throughout the same.

11. The herein described process consisting in thoroughly mixing a mineral oil with a' wet finely reduced comminuted' mineral carbonaceous material and pulverized oxides of the calcium group.

In testimony whereof I affix my signa- WALTER EDWIN TRENT.