US1932535A - Treating coal - Google Patents

Description

Oct. 31, 1933.

H. J. ROSE ET AL TREATING GOAL 2 Sheets-Sheet 1 Filed June 1, 192 9 PUMP M WW 1 M. ii i1 Z I; 1% M 312% a k 25L Wk 2% J 5?? V 2 33.; My if gig? w M W; 2% 1 4 w 1;; j Z 3; CHM. m rfm l fl a 5;

Oct. 31, 1933.

Filed June 1, 1929 H. J. ROSE ET AL 1,932,535

TREATING GOAL 2 Sheets-Sheet 2 ATORN Patented Oct. 31, 1933 UNITED STATES.

PATENT OFFICE TREATING COAL Harold J. Rose,

Penn Township,

Allegheny Application June 1, 1929.

Serial No. 367,788

1 Claim. (Cl. 44-1) This invention relates to a process and apparatus for treating coal and more particularly to the blending of coal and the removal of sulphur, ash and other non-coking constituents therefrom.

As set forth in our copending application Serial No. 97,467, filed March 25, 1926, coal may be dissolved in oils, tar, and other organic materials and the undissolved constituents may be removed by filtration, decantation and centrifuging.

Various organic materials may be used for dissolving coal. Solvents which have been found to be particularly useful are high boiling cuts of coal tar and water-gas tar, anthracene, phenanthrene, resins, high-temperature cracking products from proteleum, and various sulphurtreated oils and tars. Oil-gastar, Pintsch gas tar, and wood tar may also be used. The portions of the coal which remain undissolved are ash, minerals containing sulphur and the mineral charcoal or fusain.

In accordance with the present invention, material to be freed from ash and other matter or to be blended is placed in a porous container and the heated dissolving oils allowed to percolate through the said material, or the container with the charge is submerged in the heated dissolving oil. The coal dissolves in the oil and the resulting coal solution passes out of the container through the pores, leaving behind the insoluble matter. The temperature of the dissolving oil may vary, and the time of treatment to completely dissolve the soluble matter in the coal will vary accordingly, that is, at higher temperatures the time of treatment is shorter than at lower temperatures.

The material to be treated may be either coal, mixtures of a plurality of coals, or solid or liquid coal solutions which have previously been produced in accordance with the process described in the above application.

By the present process, it has been found possible to obtain very intimate mixtures of coals with or without other materials. If it is desired to mix' two or more coals for, coking or other purposes, these coals may be mixed in the desired proportions and treated with the dissolving agent, or the coals may beseparately treated and the resulting solutions mixed together in the desired proportions, thus obtaining a hitherto unknown homogeneity. For example, high volatile and low volatile coals are blended to produce mixtures having excellent coking properties. Also, a

poorly coking, or non-coking material, or a cata-- lytic material such as aluminum chloride or zinc chloride, may be distributed throughout the liquid blend before de-oiling.

Apparatus which may be used for dissolving coal or blending coals and removing insoluble matter, are shown in the accompanying drawings, in which Figures 1, 2 and 3 are cross-sectional views of various forms of apparatus for practicing our invention; 4

Fig. i is a cross-sectional view of a modification and shows means for rotating the porous containers for coal; and

Fig. 5 is a cross-sectional view of a further modification and shows means for raising and lowering. the porous containers.

In the, apparatus shown in Fig. 1, a porous container 1 for coal is supported within a contain er 2 for oil by any suitable means such as a support 3. The container 1 is preferably a wire basket of fine mesh and has a bottom and cylindrical side, the top edge of which is attached to the bottom end 4 of the support 3. The support 3-may comprise any means of support such as hooks or a cylinder having openings 31!. for the passage of vapors.

The top of the oil container 2 has an opening 5 through which the support 3 and container 1 may be raised and lowered, or withdrawn when desired. The flange 6 at the top of the support 3 extends outwardly slightly beyond the edge of the opening 5 and is adapted to reston the top of the oil container 2. A lid '7 is placed over the tops of the container 2 and support 3.

Any desirable cooling means 8 may be placed within the support 3. The condenser or cooling means 8 is supplied with any suitable cooling fluid for which pipe 9 serves as an inlet and pipe 10 as an outlet.

Interior heating means such as coil 11 or exterior heating means such as an annular cham*- ber 12, or both, may be employed. Steam or other hot gases may be passed through coil 11.

In the operation of the apparatus shown in Fig. 1, coal is placed in the porous container 1 and oil in the container 2. The level of the oil in container 2 is below the bottom of the container 1. The oil is heated to its boiling point and the condensed vapors collecting on the surface of condenser 8 drip down onto the coal and dissolve it while passirigbetween the particles to the bottom of container 2. The uneondensed vapors pass out through vent 13. When the solution in container 2 has become sufficiently concen- 1 other suitable method and fresh solvent supplied to the container 2.

During .the process of extracting or leaching coal or coal solutions in wire baskets or other porous containers, a filter pad builds up on the walls and bottom and helps to stop the passage of insoluble material. As soon as this pad of mineral charcoal, ash, etc., has built up to such a thickness that the flow of coal solution becomes too slow, the basket is allowed to drain and the pad of insoluble material is removed.

In some instances, it may be desirable to coat the walls and bottom of the basket with a layer of filter aids in order to facilitate the proper removal of ash and other insoluble materials. The filter aids may, if desired, be suspended in the coal solution entering the basket or may be mixed with coal before charging.

As shown in Fig. 2, the oil may be withdrawn from the bottom of the container 2 and passed into the top and sprayed over the coal in the porous container. The oil passes out through pipe 14 and is pumped through a heater 15 and thence to a spray 16. The oil then passes through the body of coal and the coal solution falls to the bottom of chamber 2 from which it passes through pipe 14 again and is recirculated. When the solution has reached the desired concentration, it may be withdrawn through pipe 17 and fresh oil introduced through pipe 18.

In the apparatus shown in Figs. 1 and 2, instead of stationary baskets, vibrating or gyratory sieves may be used or stirring means may be placed in the baskets.

In the apparatus shown in Figs. 3, a and 5, to be described, the coal is subjected to a leaching process, that is, the coal placed in baskets similar to those described above is submerged in the oil or solvent.

In Fig. 3, a battery of oil containers 19-24. is shown having suspended in each container a filter basket for coal. The battery may be heated by any suitable heating means. Above the battery is a pipe 25 for supplyig oil to any one of the containers 19-24 through branch pipes 26-31, and for removing the solution from any one of the said containers through branch pipes 32-37. Each of the branch pipes 26-31 and 32-37 is provided with a valve, and pipe 25 is provided with valves 38-43. Pipe 44 supplies compressed air to each of the containers through branch pipes 45-50, each of which is provided with a valve. Pipes 51-56 serve for the passage of gases or vapors from each of the containers to the vent 57.

Each of the containers may be provided with stirring means v 58 for stirring the coal and/or the oil. The stirring should be vigorous enough to keep the coal in suspension to facilitate filtering and to bring about the proper contact between coal and solvent.

The apparatus shown in Fig. 3 is constructed so that there may be a countercurrent or concurrent treatment of coal with oil.

To start the countercurrent process, fresh coal is placed in each of the filter baskets and fresh dissolving oil in each of the containers in the battery, the coal being submerged in the oil. It may be assumed that the coal is to be passed from the right to the left and oil from left to right. Fresh oil will always be passed into container 19 and a concentrated solution of coal in oil withdrawn from container 24:. Fresh coal will enter container 24 and the refuse withdrawn from container ie. The position of the solid. matter in the baskets in each stage of the process is indicated by the dotted areas.

Assuming that the coal in container 19 is completely extracted, the basket is withdrawn and each of the baskets in the other containers is moved to the left and lowered in to the next adjacent container. That is, the basket in container 20 is placed in container 19, the basket in container 21 in container 20 and so on. The

basket withdrawn from container 19 is cleaned,

if so desired, fresh coal placed therein, and lowered into container 24.

At the same time, concentrated coal solution is withdrawn from container 24 and each batch of solution in the other containers passed into the next adjacent container to the right. Fresh oil is passed into container 19 and the extraction again carried on until substantially all of the coal in container 19 is extracted.

Assuming that all the valves in pipe 25 and its branches are closed, and liquid is to be passed to the right from one container to the next, for instance, from 19 into 20, the valves in branch pipes 32 and 27 are opened and compressed air which is admitted through pipe 45 forces the liquid from the one container to the other;

It is obvious that by the proper manipulation of the valves in pipe 25 and is branches and in the branches of the compressed air line 44, liquid may be passed out of and to any of the containers or from one container to any one of the others. If for any reason, one of the containers is not in use, the liquid may be shunted across it without causing delay, particularly when a countercurrent or concurrent treatment is employed.

In a concurrent treatment, fresh oil and fresh coal are brought together in a container at one end of the battery and the exhausted material or refuse, and saturated coal solution are withdrawn from the container at the other end of the battery.

If desired, the branch pipes 26-31 may be so arranged as to discharge liquid directly into the filter baskets. In this way, the liquid is made to flow through the bed of coal as it enters the container and a more rapid soaking of the coal takes place.

In Fig. 4, a battery of coal-treating chambers is shown in which means for rotating the filter baskets 1 in the oil are employed. Each of the baskets is provided with a shaft 59 and attached thereto by any suitable means. In this particular modification, rotation of the shafts causes the baskets to rotate about a vertical axis although it may readily be conceived that the baskets may be so mounted as to be rotated about a horizontal axis.

The shafts 59 may be rotated by any suitable means as by bevel gears 60 and 61.

In Fig. 5, means are shown by which the baskets are raised and lowered to cause a vertical movement of the coal through the oil. In the preferred arrangement, a cylinder 62, rigidly supported and projecting downwardly a short distance from the top of an oil container, acts as a guide for cylinder 63 which slides up and down within cylinder 62, the overlapping portions of the cylinders being somewhat longer than the distance through which the basket is to be moved.

The basket is attached to the lower end of cylinder 63 and the up-and-down motion is im parted to it by connecting rod 6% and crank-shaft 65, the crank being attached to the shaft by a link 66.

By the process and apparatus of this invention it is possible that sulphur present in coal as iron pyrites, marcasite, etc., may be substantially quantitatively-removed. However, more or less sulphur is always present in coal as organic sulphur which is ordinarily very diflicult to remove.

Owing to the fact that we are able to put coal into a fluid condition, it is possible for us to treat the coal to remove also organic sulphur. Organic sulphur may be precipitated as a solid metallic sulphide or it may be adsorbed by certain solids. To accomplish this, such sulphur precipitating materials as metals, namely, copper, lead, etc., metallic oxides such as cupric oxide, cuprous oxide, lead oxide, calcium oxide, etc., or metal salts, such as carbonates, or other solids such as silica gel, etc., may be used.

These materials may be mixed with the coal in the wire baskets prior to, or at the time of solution, with the result that the sulphided material remains in the baskets with the other insoluble substances. The solid residue left in the baskets after the above treatment, generally consists of iron pyrites, slate, mineral charcoal and the sulphided material.

Large particles of sulphur minerals, especially when free from coal, are generally easily removed by existing coal washing processes, but

the smaller particles are quite difiicult or impossible to remove by such processes. Of the visible forms of sulphur the so-called cat-faces and pyrite facings in coal are the most troublesome to remove by existing processes. When coal is crushed for washing, even as fine as one-quarter inch size, a large part of this sulphur adheres to the coal particles and a large part of that which breaks free is slimed or broken into thin scales which have a tendency to flow off with the washed coal.

By the process of the present invention, practically all the visible forms of sulphur minerals and even particles of microscopic size are easily removed and it is possible to prepare a coal blend of hitherto unknown purity, particularly with respect to low ash and low sulphur content. This may be accomplished even with coal from dirty coal seams.

We claim as our invention:

A process of treating coal which comprises mixing coal with a sulphur precipitating material adapted to remove organic sulphur from coal, passing heated oil through the mixture to dissolve the coal and separating the solution from the undissolved matter.

HAROLD J. ROSE.

WILLIAMH.HILL.

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