US1507674A - Process of briquetting finely-divided materials - Google Patents

Description

No Drawing.

Patented Sept. 9, 1924. l v

UNITED STATES 'rrrnononn NAGEL, or New you, N. x.

raocns'sor nnr'aun'r'rme rmnnymrv'mnn MATERIALS.

To all whom it may concern: Be it known that I, Tmzononn New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Processes of Briquetting Finely-Divided Materials; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same. i

This invention relates to briquettes and the process of producing the same, and has for its object to improve the procedures as well as the products heretofore proposed.

With these and other objects in 'view, the invention consists in the novel steps and combinations of steps constituting the process and in the novel article of manufacture constituting the briquetted product, all as will be more fully hereinafter disclosed and particularly ointed out in theclaims.

This application constitutes'a continuation in part of my copending application, Serial No. 610,369, filed January 2, 1923, and entitled Artificial fuel and method of making the same.

order that the invention may be the more clearly understood, it is said: It is well known that a large number of different substances have been heretofore brought to a finely divided condition, mixed with a binding material, and then subjected to pressure and heat in order to form briquettes therefrom.

In the case of coal, these briquettes have gone into a rather extended use, but it is also well known that their use involves a number of disadvantages. Among the objections that exist may be mentioned the fact that many of them 've ofi smoke and odors when burned, while others are water-soluble. This causes such briquettes to become soft and to disintegrate under weather conditions usually encountered. Other briquettes are too expensive to manufacture. Also, it is recognized that some of the most promising of the prior products soften and flow together when burnin thus forming a plastic mass that cuts 0%" the draft and prevents good combustion.

It is also recognized that in burning many of the prior briquettes the binding material is often consumed faster than the finely divided coal, thus freeing the latter NAGEL, acitizen of the United States, residing at.

Application filed April 21, 1923. I Serial No. 683,806.

from the briquettes and permitting said finely. divided particles to drop unburned.

through the grate with the ashes, or to fill the passages through the burning mass and I choke oif'the draft.

It is the object of this invention, when more specifically stated, to obviate these objections by providing a procedure capable of producing a coal or other briquette, for example, that will not give oif smoke or odors when burned, one that is not water- .soluble in an ordinary sense or to an objectionable extent, one that is hard and dense and less liable to disintegrate than the prior products, and one that can be manufactured withinthe permissible limits of cost.

In carrying out this invention, when coal briquettes are to be made, one may proceed as'follows: The coal, if anthracite for example," may be finely subdivided as usual, or to sizes between, say, of an inch and a 200 mesh size. This finely divided material can be-dried or not as desired. Then take by weight 100 parts of this finely divided coal and thoroughly mix therewith in any suitable manner, say, about 7 parts of what is known in the art of wood pulp manufacture as sulphite pitch. That is, the well known waste liquor from wood pulp mills is boiled down or concentrated to a viscous and adhesive condition when it is called sulphite pitch. To this pitch I add for each 100 parts of coal by weight about 1 parts of phosphoric acid H ,PO

It is best to mix the pitch and phosphoric acid together to form the binder before applying it to the coal. The mass thus produced and consisting of the finely divided coal and binder, is or may be next subjected to the pressure usually employed in the making of briquettes, and thereafter heated to a temperature which ordinarily should not exceed about 800 F., and then cooled. The resulting briquettes are found to possess a water-insoluble, dense, hard, strong structure that burns without emitting smoke or odors, nor do said briquettes softener flow while burning. That is, the mixture of sulphite pitch and phosphoric acid constitutm the binder under the influence of heat, wi 1 be found to have been converted into a hard, strong, tenacious and water-insoluble material that does not run or fuse at the temperature of burning, and therefore serves to hold the coalparticles firmly together during storage, shipment, and use,

The above applies especially to anthracite coal, and coke. WVhen bituminous coal or lignite is employed they first have to be heated to a temperature of at least 800 1 to drive off a substantial portion of the volatile matter previous to comminuting and briquetting the coal.

I am unable to give a satisfactory scientific explanation of the exact chemical changes that take place in the binder under the influence of heat, but it is possible that the orthophosphoric acid, H,PO is first converted to the pyro form, ILP O and finally to the meta form H1 0 in accordance with the well known behavior of these compounds when heated. It is further possible that one or more of these acids react with the constituents of the pitch or with those of the coal, or with both, to form hard, tenacious, water-insoluble compounds therewith. WVhatever may be the true explanation, actual tests have abundantly shown that the finished product possesses the surprising and valuable properties above mentioned. and further that this finished water resisting heated binder that is infusible at the temperature of burning the fuel, has the remarkable property of sticking to and. binding together finely divided substances other than coal, among which may be mentioned flue dustfrom smelter plants containing metallic oxides, soot, etc. In fact, I have found that this unheated mixture of sulphite pitch and phosphoric acid possesses the valuable property of being water-soluble and therefore capable of being easily applied to and binding masses of finely divided materials in general, and that when heated such a change takes place therein that it becomes so hard, strong, and tenacious that it converts a wide range of such materials into hard, strong, tenacious and weather resisting briquettes.

The invention is not limited to the proportions above given, nor to the tempera tures stated. In fact, I have found that instead of using by weight 7 of sulphite pitch, I may use on various coals quantities varying say between "3% and 15%; and instead of using 1 H PO I may use quantities varying between, say, of 1% and 5%. When briquetting other materials such as flue dust, finely divided ores in general, etc., that it may be desired to conglomerate, I use varying quantities of the binding material according to the nature of the material being briquetted, and the use to which it is to be subjected.

Further, the tem erature employed will likewise vary. In the case of coal, it is not necessary to exceed, say, 1000 F., and often not necessary to exceed, say, 400 F.

It will now be clear from the foregoing that I have disclosed a procedure which provides agglomerated lumps, or bodies in general, and especially a fuel product that differs from other prior products in. that it possesses the following qualities, all of which qualities no single prior fuel product possesses, to my knowledge. That is, this product is hard, tough, and sufiiciently water-insoluble to resist softening due to all influences of weather, such as hard rains, etc. It burns freely and does not clinker while burning it emits no smoke or odor and does not soften, flow or disintegrate; and the ash content of the coal is not substantially increased by the binder. By water-insoluble I mean such an insolubility of the agglomerate as will prevent it from softening to an undesirable degree when subjected to rains or other atmospheric conditions. The raw material used in making the binder can be produced in unlimited quantities so that the supply and the cost of the binder will not be materially disturbed by this new industrial application. Further, it is not necessary to use commercially pure phosphoric acid. I have found that a very crude and comparatively inexpensive phosphoric acid which is pro duced by merely treating phosphate rock with sulphuric acid without refining can be employed in my process.

This invention differs from that of my copending application Serial No. 633,805 of even date herewith and entitled Agglomerated finely divided material and process of producing the same, in that this invention employs a binder containing a sulphite pitch.

It is obvious that those skilled in the art may vary the details of my procedure as well as of my product without departing from the spirit of the invention, and therefore I do not wish to be limited to the foregoing disclosure except as may be required by the claims.

What is claimed is:

1. The process of agglomerating a finely divided material which consists in mixing said material with a binder containing sulphite pitch and combined phosphorus, such binder being capable of hardening upon heating; and heating said mixture to a temperature sufficient to harden said binder.

2. The process of agglomerating a finely divided material which consists in mixing said material with a binding organic material containing sulphite pitch and combined. phosphorus, which upon heating is capable of forming a hard water insoluble binder; compressing the mixture thus produced; and heating said mixture to a tem perature sufficient to harden said binder.

3. The process of agglomerating a finely divided material which consists in mixing said material with a binder containing sulphite pitch and combined phosphorus, and

also capable of hardening under the action I of heat; compressing the mixture thus proaction of heat; compressing the mixture thus produced; and heating said mixture to a temperature above 500 F. to harden said binder.

5. The process of agglomerating a finely divided material'which consists in mixing said material with an organic water soluble binder containing a sulphite pitch and combined phosphorus, and capable of hardening upon heating; and heating said mixture to a temperature suflicient to harden said binder.

6. The process of agglomerating a finely divided material which consists in mixing said material with a binding organic material containing sulphite pitch and combined pho horus, which upon heating is caable of orming a hard, water-insoluble inder; compresslng the mixture thus produced; and heating said mixture to a temperature above 600 F. to harden said binder. 7. 'Ihe'process of agglomerating a finely divided material which consists in mixin said material with a binder containing s phite pitch and combined phosphorus, said binder capable of hardenin under the acproduced; and heating said mixture to a temperature above 700 F. to harden said binder.

8. The rocess of briquetting a finely divided car onaceous fuel which consists in mixing said fuel with a binder containing sulphite pitch and a phosphoric acid; com.- pressing the mixture thus produced; and heating said compressed mixture to a temperature above 400 F.

In testimony whereof I aflix my signature.

THEODORE NAGEL.

tion of heat; compressing t e mixture thus