US1880116A - Explosive composition - Google Patents

Description

?atented Sept. 27, 1932 uiarra stars F H Ii RICHARD H STRATTON, OFJBERKELEY, CALIFORNIA, ASSIGNOR TO ATLAS POWDER COMPANY, OF WILMINGTON, DELAWARE, A. CORPORATION OF DELAWARE v nxrLosIvE coMros'rrIoN N 0 Drawing.

This invention relates to explosive composions and particularly to the type known as dynalnites and to the use of'novel carbonaceous combustible materials in the preparation F- of such explosive compositions. VThe chief object of the invention is to provide novel, economical, solid, carbonaceous combustible ingredients, having relatively high densities and relatively low absorbencies for the liquid explosive" ingredients. F u-rther objects will become apparent with the following description of my invention, such as, for example, (l) the provision of carbonaceous in-- gredients for dynamite with little or no de:

sensitizing effects on the explosive ingredients in contact therewith and (2) the provision of carbonaceous ingredients for dyna-.

mitehaving domestic sources of supply. I

So-called dynamites usually comprise one or more solid and/or liquid explosive'com; pounds, such as nitrogylcerine, nitroglycol, nitropolyglycerine, dinitrotoluene, trinitrotoluene, nitrocotton, nit-ro-starch, and the like; one or more oxygen carrying salts, such volved with the choosing of a fuel for a dynamite are described herewith. First, the fuel must be such that it will not induce instability in the explosive compound or compounds, with which it is to be in direct conas ammonium nitrate, sodium nitrate and sensitivities Application filed February 27, 1931. Serial at. 518,916.

tact; second, it must be such that it will not desensiti-ze the explosive compound or compounds after extended contact; third, it must be such that it will hold the liquid constituents by absorption and thereby prevent exu-' dation orx leakage, without having so much excess absorption that the explosive will be Y 'rendered too insensitive to be detonated by ordinary explosive initiators and to propagate efiiciently; fourth, it must have proper density or, specific gravity to impart the re-' quired density to the ultimate ex losive for the desired density of loading; fi th, it must. have proper particle size and be of such physical structure as to not only-impart-the desired velocity of detonation but also to provide proper aeration in the ultimate explosive, when mixed with the other ingredients; sixth, its color must be as light as possible to impart a good appearance to the ultimate explosive; seventh, its chemical composition must be such as to provide the evolution of a "large volume of gaseous products of combustion, resulting in good strength effects by the ultimate explosive; and eighth, it must reqzire an amount of oxygen to complete its 0 mbustion, which can be provided by lim- 1 ited amounts of economical oxygen carriers,

in order to assure the evolution of minimum amounts of poisonous gases in the products 7 of detonation of the ultimate explosive. From'theabove, it will be seen that there areseveral requisites which are common to all types of dynamite fuels, whereas other,

' requisites are dependent upon the particular types of 'ultimateexplosive compositions involved. The chief requisites of the latter type are those involving thedensity, the fineness (particle size) and thefabsorbency of the dynamite fuel. For example, a dynamite of the straight nitroglycerine type requires a highly absorptive fuel, such as wood pulp, sawdust and the like, in order that. the liquid nitroglycerine will be held by absorption en-' tirely, whereas a low density permissible explosive, having a relatively small nitroglycerine content, requires a low density fuel, with as low' absorbency as possible, such as bagasse pith and the like.

Likewise, it is just as important to have a satisfactory fuel, having a relatively high density and a relatively low absorptive cag pacity for liquid explosives, for use 1n controlling the density and absorption of many types of dynamite. For certain types of dynamlte, such as, for example, low strength gelatin dynamites, practically no cellular ab sorption is required at all; the nitroglycerine being merely held by gelatinization with nitrocotton and by adherence to the surfaces the low strength nitroglycerine dyn mites,

the intermediate-stren hs of gelati dynamite and nearly all 0 the so-called ammo- In this case, just nium nitrate dynamites. enough absorption must be provided to prevent the exudation or leakage of the liquid ingredients;- an excess of absorption being avoided by the useof the relatively dense,

and relatively poor absorbent type of fuel.

; Heretofore, vegetable ivory meal has been extensively .iulfill the functions of a relatively denseand and almost exclusively used to poorly absorbent fuel. 1 "It is derived from the vegetable ivory nut, which is imported into.

the United States from tropical countries,

chiefly for the purpose of making buttons; the-scrap and waste material from the button manufacture being reduced to eomminuted cform for use as the dynamite-fuel. availability of this material is accordingly directly and entirely dependent upon the operation ofthevegetable ivory button fac .tories, since the high cost ofimporting the vegetable ivory nuts would prohibit their importation for use in dynamite alone. In

view of this situation, it is quite evident that it would be advantageous to have a similar type of-dynamite fuel, the source of supply of which is domestic as well as more stable and assured. 1

After extensive research andthe study and trial of-many types of carbonaceous materi- I als from various sources, I have discovered a material which not only fulfills all of the general or commonereq uisites for a dynamite fuel, but also fulfills all of the special requisltes, peculiar to a fuel having relatively high density and low absorbency. This material is eomminuted almond hulls, which I have also referredto as almond hull pulp.

Comminuted almond hulls or almond hull I pulp has the'advantages over vegetable ivory meal, of being a domestically grown product, and of being aiby-product from an edible nut.

For these reasons, its supply is more stable;

" less subject to the normal fluctuations of the meal.

manufacturing industry than that of vegetable ivory meal, and more economical.

Extensive-tests have also shown almond hull pulp to induce noobjectionable destabilizing or desensitizing elfects on such liquid explosive as nitroglycerine and nitroglycol.

It has also been found to require exactly the same amount of oxygen, per unit weight, tocomplete its combustion, as ordinary wood pulp. Its ash content (about 2%) is also well within the normal range for commonly used dynamite fuels and its ultimate analysis shows the proportions of carbon and hydrogen to be quite comparable with various carbonaceous materials, which have long been used successfully as dynamite fuels. Satisfactory explosive strength results also confirm the satisfactory gas producing quality for almond hull pulp, when used in liberal quantities in dynamite. Its light ochre color is also quite satisfactory for a dynamite fuel of its type.

Although the density of almond hull pulp is not quite as high as that of vegetable ivory meal, it is sufliciently high to be used almost as a direct substitute for vegetable ivory Experiments have shown that the same density maybe retained in a dynamite composition by replacing a small amount of a comparatively light and highly absorbent fuel, {in addition to the replacement of all of the vegetable ivory meal, in the original composition. By using this procedure, the almond hull pulp not only has the advantage of entirely replacing all of the vegetable ivory meal but also may have the advantage of replacing a portion of a more costly absorbent fuel as well. In fact,'it has been determined that the slightly lower density of almond hull pulp, as compared with vegetable ivorymeal, entails a corresponding slight increase in absorbency,'which permits of the substitution procedure, described above, with the retention of proper absorp- ;tion as well as density in the ultimate dynamite composition. N

The following table shows examples of dynamite compositions, which serve to illustrate the application of the substitution P Q' cedure described above.

40% dynamite A 35% gelatin (amm. mt. type) dynamite Nitrocotton.

Number 6! 1%X8 ctgs. per 50 pounds Sensitiveness to detonation. Velocity oi detonation-MP5.

, "pensive and troublesome methods which have.

Additional examples of dynamite compositions, using almond hull pulp as a fuel, are shown in the following table:

Per cent Per cent Per cent N itroglycerine 22. 5 19. 5 10. 5 TNT 2. 3 8. 5 Nitrocotton 3 Ammonium nitrate 5. 0 75. 0 Ammonium perchloratm 5. 0 Nitrate of soda 54. 8 52. 0 5. 0 Almond hull pulp 4. 6 14. 0 5. 5 Starch 5. 0 Sulphun 5. 0 Ant-acid 5 1.0 .5 Sawdust 5. 0 Bagasse pith 3. 5

To those versed in the art of formulating dynamite compositions, it is well known that the particle size or fineness of a carbonaceous dynamite fuel plays an important part in afi'ecting various properties of the ultimate dynamite composition, examples of which are the velocity of detonation, the sensitiveness, the cohesiveness, the Water resistance and the density. It is for this reason that various degrees in the fineness of such fuels as vegetable ivory meal have been employed to control such properties in a dynamite composition, as exemplified above.

The degree of fineness of almond hull pulp, I have discovered, has very similar effects on these properties as that of vegetable ivory meal. In fact, almond hull pulp has an additional' advantage over vegetable ivory meal,

"because of the fact that vegetable ivory scrap often includes a large proportion of relatively fine particles, whereas almond hulls are usually obtainable in comparatively coarse form; thereby permitting a larger proportion of relatively coarse almond hull pulp to be derived from almond hulls, if desired, than the proportion of relatively coarse vegetable v ivory meal, derivable from the average rim of ivory nut scrap.

Another advantage arising from the use of almond hull pulp, particularly in relatively coarse form, in contradistinotion to the use of. other forms of ground nut shells, is the ease and completeness with which the meats may be separated from the hulls. I am aware of the fact that it has heretofore been proposed to use other forms of nuts, such, for example, as walnuts and pecans.

However, the use of almond hulls presents marked advantages over any other nut shells or hulls which have ever been proposed for the purpose stated. For example, the patent to Bar'ab, No. 1,280,634 discloses the very exto be resorted to to separate the shells of such T nuts as walnuts and pecans from the adherent meats which are found clinging to them when they are received by the explosives manufacturers. Further, walnut and pecan nut shells are much more oily that almond hulls, and oily materials are .desensitizers and must be avoided, in the relationship in which I amount of almond hull namely, as a substitute for ground vegetable ivory. Further, almond hulls present a difference in kind even with respect to the scarce and expensive ground vegetable ivory for which I propose to substitute it, in that it is decidedly less gritty than the ground vegetable ivory and it is well recognized that grittiness of dynamite particles involves an increased hazard in use as well as in manufacture. Almond hull pulp possesses the desired low absorbency or the capacity to retainthe nitroglycerine in the form of a surface film rather than as an absorbed constituent without being so compact as to enter into combustion with diificulty. In this respect it is superior to the more expensive ground vegetable ivory and by its use it is possible to make gelatlns and low nitroglycerine dynamites with good propagation sensitiveness and very ployed as a dynamite fuel, although I preferit to include no particles, sufficiently large to be held on ascrgen having a 0.10 inch square-opening, for-my purpose. While I have found thatlalmond hulls may be suitably reduced to almond hull pulp by means of either an attrition millor squirrel-cage mill,"it is to be understood that my invention is not limited to these types of mills, but that any type of mill, grinder, pulverizer or disintegrator may be used to reduce the almond hulls toalmond hull pulp of any fineness desired,.without being outside the scope of my invention.

It should also be clearly understood that the almond hullpulp may be substituted for all or part of one or more combustible fuels, in any type of explosive composition and that it may beused either alone or in conjunction with other combustible materials, without departing from.my invention, and that the pulp employed may be varied at will, since I contemplate using up to about of the same. It is also understood that the invention covers the use of almond hull pulp in conjunction with various types of-liquid explosive materials, both in then liquid and gelatinized states. As examples of liquid explosives that may be employed, in conjunction with almond hull pulp, I may mention nitroglycerine, tetra nitrodiglycerine, glycol dinitrate or oily dinitrotoluene. Various solid explosive materials may be. used; for example, crystalline di-- per cent of almond hull pulp as a combustible dued for safety toward the ignition of gases or dusts in mines, in ways well. known to those skilled in the art.

To avoid any possible misinterpretation, I wish it clearly understood that the terms comminuted almond hulls and almond hull pulp are inclusive of the terms ground a1-- mond shells.

Having described my invention, what I claim is:

1. A dynamite containing almond hull pulp as a combustible'ingredient.

2. A gelatin dynamite containing almond hull pulp as a combustible ingredient.

3. A non-gelatinous dynamite containing almond hull pulp as a combustible ingredient.

4. A dynamite composition containing from one-half of one per cent ,to twenty-five ingredient. p

5. A dynamitecomprising a fuel consisting of comminuted almond hulls and a liquid explosive ingredient for whichsaid almond hulls have at least partial absorbent capacity.

6. A dynamite comprising an oxidizing material, comminuted almond hulls and a liquid explosive ingredient for which said almond hulls have cnt capacity. L

7. A dynamite'comprising an oxidizing material, comminuted almond hulls and a liquid explosive ingredientfor which said almond hulls have at least a partial absorbent capacity, and whereinthe almond hulls at least a partial absorbhave been comminuted to such a degree as to pass through a 0.10 inch square opening.

8. A dynamite comprising a carbonaceous fuel consisting of almond nitroglycerine. I

' In testimony whereof I, RI'GfiARn H. STRAT- TON, affix my signature.

RICHARD H. STRATTON.

hull pulp, and