US2184621A - Treated fuels and method of treating the same - Google Patents

Description

Patented Dec. '26, 1939 TREATED FUELS AND METHOD OF TREATING THE SAlVIE Richard 0. Marmaduke, Kansas City, Mo., as-

signor to Sherman Marmaduke, Kansas City,

N Drawing. Application April 6,1938,

Serial No. 200,419

10 Claims.

This invention relates to treated fuels and particularly to a treating material and the application thereof to solid fuels, such as coal, the present application being a continuation in part of my copending application, Serial No. 85,731, filed June 17, 1936.

It is well known that weathering of freshly mined coal results in degradation by reason of its rapid oxidation and disintegration when acted upon by air or other elements. In fact, certain types of coal disintegrate so rapidly that they are reduced to slack in a very short period of time. Degradation also does not cease at the end of the weathering period since handling and shipping of the coal results in breakage and abrasion of the lumps to expose new surfaces to oxidation. Another disadvantage of coal as a fuel is the fire hazard brought about by oxidation of stored fuel where there is sufficient air to effect the oxidation but insufiicient air to carry away the resultant heat, thereby causing spontaneous ignition. The softer grades of fuel which are more readily subject to slacking and mechanical disintegration are especially not desirable as fuels for domestic use because of the dust and dirt resulting therefrom.

I am well aware that various attempts have been made to apply protective coatings to coal, such as wax, oils and the like, but they have not 3 been completely successful in providing a fuel that satisfactorily overcomes the degrading characteristics of coal as a fuel. Many of the treating materials have, in fact, introduced other unfavorable characteristics because they render the coal greasy, odoriferous, and difiicult to handle. For example, crystalline wax, such as paraffin, has been suggested for coal treatment, but pure crystalline wax has not proved satisfactory because of the excessively large amount of wax required and the extremely brittle characteristic thereof when it is congealed on the coal. When handled the wax scales off, leaving the surfaces exposed to weathering and abrasive action, as in the instance of coal not so treated. To overcome the difficulty of crystalline wax, amorphous wax, such as petrolatum, has been used, but the treated coal is extremely messy and disagreeable-to handle. Various oils have been suggested but oil has not proved satisfactory as a protective coating unless an excessive amount, or a viscous oil, is

applied, with the result that such coating is extremely messy to handle and inconvenient to store because of drainage of the oil. Light volatile hydrocarbons are not satisfactory because they '55 are highly odoriferous, evaporate quickly and soak pointed out.

into the pores and capillaries of the coal to such an extent-that they leave the surfaces comparatively dry andsubject to' abrasion.

Fuels have also been treated with wax solutions which'included crude petroleum, kerosene, and 5 other highly volatile vehicles, but vehicles of this character are highly odoriferous, evaporate rap idly and soak into the coal, leaving the wax ex tremely crystalline and brittle'so that it is subject to scaling in the same manner as pure wax. 101

It is the purpose of the present invention. to provide a coating material that affords better protection of solid fuels'without theobjectionable characteristics of the treating materials above In the present invention I provide a material which forms a pliable, slippery coating of crys talline character that is impervious to the action of air and other elements leading to degradation.

The coating material consists of a crystalline wax 20 I of the parafiinic series, blended with a liquid hydrocarbon that tempers the crystalline character of paraffin wax so that it is not subject to scaling, andwhich provides for application in a relatively thin, cohesive film substantially imperceptible, but 25 which thoroughly protects the coal'from disintegrating action of the elements.

, To maintain the tempered character of the wax, the liquid hydrocarbon must be substantially non viscous and of low volatility so that it will not distill ofi at-the melting point of the wax. Since parafiin wax of the character contemplated melts at a temperature of to F., the liquid hydrocarbon should have an initial distillation point nolower than the melting point of the wax, 35 preferably no lower. than 325 F., and aburning rate in excess of 16 hours. This is extremely important because liquid hydrocarbons, such as kerosene and the like, having a burning time of less than 16 hours are too volatile to form a blend 40 having the desired plasticity. I also find it essential in eliminating greasy characteristics of oils and to assure substantially dry set upof the paraffin wax, that the liquid hydrocarbon have'a Saybolt viscosity of no more than seconds at 45 100 F. The non-viscous character of the liquid hydrocarbon is also important in that the blend must penetrate; sufiiciently into the capillaries of the coal to firmly anchor the coating without excess penetration, as in theinstance of volatile hydrocarbons such as'kerosene, benzine, benzol, and similar liquids. The body of the liquid hydrocarbon also important in forming a blend with the ,wax that is stable at ordinary temper 55 atures and not subject to vaporization or softening of the wax.

Many of the non-explosive liquid hydrocarbons of the burning oil series, commonly known and described as fuel oils, which have a distillation point no lower than 325 F., an end point below 775 F., and a burning rate in excess of 16 hours, with a Saybolt Viscosity test of less than 150 seconds at 100 F., may be used, namely a distillate, furnace oil, or gas oil falling within these qualifications. I find from actual practice that Nos. 1, 2 and 3 furnace oils have the specifications set out in the United States Department of Commerce Bulletin No. 0812-35, entitled Commercial Standard Fuel Oils, 3rd edition, is satisfactory. The materials may be blended in various proportions, however, I have found that a blend product consisting of from 8 to 30 per cent parafiin wax to the total Volume produced is economical and gives satisfactory results.

The essential specifications of Nos. 1, 2 and 3 furnace oil, set out as a commercial standard in the above entitled publication, is as follows:

arises when placing it in a bin or moving it for use.

Attention is here directed to the fact that the liquid employed in the blend is not a vehicle for the wax as in the case of kerosene and other volatile liquids, but it acts and remains with the wax to form ahomogeneous compound and a stable blend in producing the coating having characteristics different than a coating formed by wax or oil alone.

What I claim and desire to secure by Letters Patent is:

1. The process of treating solid, individual lumps of coal to resist degradation incidental to weathering and handling the coal, including coating the coal with a crystallizable solution consisting of paraffin wax and a liquid hydrocarbon having a burning time of more than 16 hours and a Saybolt viscosity of less than 150 seconds at 100 F., and effecting crystallization of said applied solution for forming a dry substantially non-volatile film covering on said lumps.

Distillation temperatures Viscosity (seconds) Flaghfipomt Pol-n. N o a (d t 8%; t gaybm 0. re e escnp ion percen nivers P point End (at F.) point Min. Max. Max. Max. Max. Min Max. Min Max Min 1 Afdisltillate oil for use in burners requiring a volatile 100 or legal 150 15 420 600 ue 2 A distillate oil for use in burners requiring a modor legal 190 15 440 620 600 erately volatile fuel. 3 A distillate oil for use in burners requiring a low 110 or legal 200 I 15 3 620 7O viscosity fuel.

In preparing a blend, paraffin wax is heated to the melting point and mixed with heated liquid hydrocarbon to form a homogeneous mixture that may be applied to the coal in various ways, for example, by maintaining the blend in heated condition and applying it in spray, atomized or vapor form to the coal while it is being conveyed or handled at the mine, or the coal may be dipped in the blended solution and the excess material blown off by an air blast or mechanical agitation.

After the blended material has been applied on the coal, it remains in sufiricient plastic condition to prevent scaling, but the coating is sufficiently dry to obviate the greasy and mussy characteristics of coal treated with viscous oils, petrolatum and the like. The coating has sufficient lubricating characteristics to act as a lu: bricant to eliminate grinding and abrasion incidental to shipping of the. coal, so that the surfaces are not exposed to weathering action of the air. The coating is also water-repellant to prevent freezing of the lumps or particles of coal together during freezing temperatures. The lubricating character of the coal facilitates handling and passage through chutes, hoppers, and the like. The coating has suificient fluidity to penetrate and seal the fissures and pores of the coal to the exclusion of the elements.

The treated coal therefore not only has the same calorific value as when mined, but the B. t. u. value is increased by reason of the burnable character of the coating. This character of the coating prevents oxidation by the elements and promotes ignition or kindling of the coal when used. Since the treated coal does not slack it is clean to handle and no dust or dirt 2. The process of treating solid, individual lumps of coal to resist degradation incidental to weathering and handling the coal, including coating the coal With a crystallizable solution consisting of paraffin wax and a liquid hydrocarbon distillate having a burning time of more than 16 hours and a Saybolt viscosity of less than seconds at 100 F., and efiecting crystallization of said applied solution for forming a dry substantially non-volatile film covering on said lumps.

3. The process of forming a dry crystalline film on solid, individual lumps of coal to resist degradation incident to Weathering and handling the coal, including coating the coal with a crystallizable solution consisting of paraffin wax and a liquid hydrocarbon having an initial distillation point above 325 F., an end point below 775 F., a burning time of more than 16 hours, and a viscosity no higher than. 150 seconds at 100 F., whereby said solution when crystallized on said lumps forms a dry substantially non-volatile film of sufiicient pliability to be non-scaling.

4. The process of treating solid, individual lumps of coal to resist degradation incidental to weathering and handling the coal, including coating the coal with a crystallizable solution consisting of paraflin Wax and a liquid hydrocarbon having a burning time of more than 16 hours and a Saybolt viscosity of less than 150 seconds at 100 F., said paraffin wax being in the pro- 1 5. The process of treating solidi, individual lumps of coal to resist degradation incident to weathering and handling of the coal, including coating the coal with a crystallizable solution consisting of paraffin wax and furnace oil having a maximum flash point of from 150 to 200 R, an end point of approximately 600 F., a Saybolt viscosity of approximately seconds at F., and a burning time of more than 16 hours, and eiiecting crystallization of said solution to form a coherent film on said lumps of substantially dry and non-volatile character.

6. The process of treating solid, individual lumps of coal to resist degradation incident to weathering and handling of the coal, including coating the coal with a crystallizable solution consisting of paraffin wax and furnace oil having a maximum flash point of from to 200 R, an end point of approximately 600 F., a Saybolt viscosity of approximately '70 seconds at 100 F., and a burning time of more than 16 hours, the parafiin wax being in the proportion of 8 to 30 per cent paraffin wax to the total volume of the solution to produce a thin crystalline filmlike coating on said lumps of coal which remains dry and substantially non-volatile under storage conditions.

'7. A coal treating preparation consisting of paraffin wax tempered with a liquid hydrocarbon having a burning time of more than 16 hours and a Saybolt viscosity of less than 150 seconds at 100 K, said preparation existing when in applied form as a substantially non-greasy and non-volatile crystalline film. l

8. A coal treating preparation for resisting degradation incidental to weathering and handling of coal, consisting of parafli'n wax and a liquid hydrocarbon having a burning time of more than 16 hours and a Saybolt viscosity of less than 150 seconds at 100 F., said paraflin wax being in the proportion of from 8 to 30 per cent to the total volume of the solution, whereby said solution when applied to the coal exists in a thin pliant and coherent crystalline film of substantially non-volatile character.

9. A coal treating preparation consisting of a blend of paraifin wax and furnace oil having a maximum flash point of from 150 to 200 R, an end point of approximately 600 F., and a Saybolt viscosity of approximately '70 seconds at 100 F., so that said preparation when applied crystallizes and exists as a thin pliable and coherent film of substantially non-volatile character.

, 10. A coal treating preparation consisting of paraflin wax and furnace oil having a maximum flash point of from 150 to 200 R, an end point of approximately 600 F., and a Saybolt viscosity of approximately 70 seconds at 100 F., the paraffin wax being in the proportion of 8 to 30 per cent parafiin wax to the total volume of the solution, said preparation being characterized by ability to crystallize and form a thin pliable film when applied to the coal.

RICHARD C. MARMADUKE.