US1772695A - Explosive and process for making - Google Patents

Description

Patented Aug. 12, 1930 ROBERT G. WULFF, 03 L08 ANGELES, CALIFORNIA EXPLOSIVE AND PROCESS FOR MAKING No Drawing. Application. filed Harchl,

This invention relates to an explosive which is capable of becomingharmless within a reasonably short interval after being loaded into a bore hole. One of the objects of this invention is to produce such an explosivehaving the added advantage of producing less and less carbon monoxide the later it is fired. Other explosives of this class, the liquid oxygen explosives, produce more'and more carbon monoxide the later they are fired, because the I oxidizing agent evaporates very rapidly.

Another 'object 'of my invention is to produce an explosive'which may be easily m1xed together at place of use from relatively harmless and cheap materials. My explosive comprises a solid oxidizing agent and a volatile combustible. Liquid oxygen explosives comprise a volatile oxidizing agent and a fixed combustible.

An advantage of myexplosive is that the oxygen-bearing constituent" is solid, and

. the climate or the nature of the work, so as to control the rate of evaporation. I do this by adding heavier or lighter hydrocarbons.

In my explosive, the oxidizing agent may be a chlorate or perchlorate. It may alternativelyjbe ammonium nitrate or' other nitrate, or even a perox'ide', such as calcium or barium peroxide. The combustibleis a normally gaseoushydrocarbon, such as propane or butane, preferably the latter. Very volatile casin head gasoline or petroleum ether is also suitable, but pure liquefied butane is 1929. Serial No. 345,249.

preferred. Also a mixture of hydrocarbons containing butane and lighter constituents may be used.

My explosive is produced by wetting the oxidizing agent with the combustible to saturation, over saturation, or undersaturation, in respect to either'the'capacity of the oxidizing agent for physically holding the combustible or for oxidizing it. I prefer to oversaturate the oxidizing agent in both respects since the volatility of the combustible soon diminishes the excess of the latter. The saturation is preferabl' accomplished by dipping a cartridge 0 oxidizin agent, in a porous or open envelope, suc as of cloth or paper, completely into a container full of liquefied combustible. The oxidizing agent, now saturated, is then lifted out and thereafter used, as an explosive as soon sible; that is, loaded into the bore proximately within half an hour. plosive will lose its power of ex at least of exploding violently, i is attempted after a longer interval than an hour. The exact time depends upon the tightness to which the bore hole is tamped, and other factors, such as the size of the bore hole hole ap- The ex-. loding or and the volatility of the combustible. While I may fire the explosive with only a fuse or electric squib when only low explosive power is required, I find that for high exiplosive force it is necessary to ex lode the ly a No.

mixture with a detonator, prefera 8 fulminate detonator.

Under some conditions, for instance, in hot climates, I find it advisable to alter the composition of my explosive to the extent of adding an" absorbent material to the oxidizing agent before mixing the combustible therewith. Such absorbents are referably incombustible, such as silica gel, liieselguhr, or adsorbent clay. I may use combustible adsorbents such as activated charcoal, wood flour or, sawdust, but only in small percentages, that is, 5% by, weight or less of the oxidizing as posthe firing following ranges:

/ Per cent Oxidizing agent 60-95 Absorbent 1-15 Volatile combustible 5-40 Proportions are intended to be varied according to the-kind of work to be done and the specific material employed.

The mixture should be so adjusted so that at the time it is tobe fired, there is no excess or deficiency of combustible with reference to the amount of oxidizing agent present.

The container necessary may or may not.

be combustible. It must allow the volatile combustible to leave the charge as it evaporates. This may be accomplished by having a container with a hole near the top comlose, dlnitrotoluene, trinitrotoluene, etc.

municating to the atmosphere. It may also be done by making the container wall of suitable porosity therefor, while at the same time preferably retaining the combustible as long as it is inthe liquid phase. 7

After the mixing has once taken place, the combustible is not to be hindered from evaporating except by the resence of an absorbent or'by the resence o the tamping in the bore hole. Bot of these do not absolutely prevent escape of the combustible. I'may use a permeable container for my ex losive, however, such as a cardboard cylin er, pa er wraping, cloth bag, or even asbestos ag. The atter, while expensive, has the advantage that the oxidizingcharge maybe packaged and shipped,out"of contact with any combustible substance whatever so that'fire risk is eliminated.

In order to'diminish the hygroscopic tend-j enciesof any of my oxidizing agents, I may coat the particles thereof with any of the usual protective coatings, such as nitro-celllpoxidizing agents may be varied as to their particle size from crystals the approximate size of a pea down to a finely round condition. In general the more finely ivided the oxidizing agent, the quicker. and more powerful will be the explosive. I

' Instead of using a singleoxidizing agent I may mix those which I haveenumerated, but a chlorate or peroxide should never be mixed with ammonium nitrate.- I may substitute for part of expensive oxidizing agents, however, such as perchlorates, up to 50% of cheaper ones, such as-sodium nitrate- In cases where an explosive of the maxiexplosive up to hydrocarbon liquid, such as a mixture of propane and butane, even with small proportions of ethane.

I claim as my invention:

1. An explosive comprising an unsealed combustible liquid more volatile than pentane and a solid oxidizin' agent.

2. An explosive accor ing to claim 1 in which the volatile combustible liquid is a hydrocarbon normally gaseous at atmosp eric temperature and pressure.

3. An explosive comprising a mixture of a solid oxidizing agent and a liquefied normally gaseous mixture of hydrocarbons substantially open to theatmosphere.

4. An explosive comprising a perchlorate and a liquefied normally gaseous mixture of hydrocarbons substantially open to the atmosphere'. 1

5, An explosive comprising a perchlorate,

an alkali-metal nitrate and a liquefied nor-v mally gaseous mixture of hydrocarbons substantially open to the atmosphere.

6. An explosive comprising a solid oxidizing agent, an absorbent and a substantial proportion of an unconfined petroleum hydrocarbon liquid more volatile than pentane.

7. An explosive comprising a solid oxidizing agent, a non-combustible absorbent and a su stantial proportion of an unconfined petroleum hydrocarbon than pentane. o

8. An unsealed explosive comprising an oxidizing salt and a volatile combustible liquid a substantial proportion of which is liquid butane. 9. An. explosive having a liquefied volatile oxidizable constituent and capable of losing. its explosive power after a few hours exposure to atmospheric temperature and pres- A liquid more volatile sure by reason of the evaporation of its said 1 oxidizable constituent.

10. 'Anexplosive comprising a solid oxidizing agent and an initial excess of a combustible liquid more volatile than pentane over that required for complete consumption of the oxygen of the oxi plosive tions of tem erature and pressure of being altered. as to its oxygen balance so that more complete combustion will occur after an interval of exposure to such atmospheric -con ditions. p

11. An explosive comprising an oxidizing salt, finely divided aluminum and a substan tial proportion of a liquid hydrocarbon more volatile than entane. v

12. An exp osive com rising an oxidizing salt, silicagel and a su tantial proportion 'zing agent, said exeing capable at atmospheric condi asse ses of a liquid hydreeerben mere missile shim pentaneq 13. An expiesive eemprisin en @Xidisin 7 salt, silica gel, aluminum pew er and iiqizi bumme a 14. An explosive comprising an exidizing salt the particles whereof have s. pretestive coating and a, substantial pmportien ef a liquid hydreeerben mere veietiie fuham penbane.

m 15. The process of making an explesive adapted to seem lose iis explosive power under atmospheric cenditiens which com rises dipping a charge eemprisin an oxi izing ssh:

eenta-ined in a porous is ric cemteimer into a vessel centeimng a substantial quemtisy M a liquefied mixture 05 bydmcar one more volatile than penises, and then withdrawing said charge.

1.6..Ti1e process 0f making an expiesive capable of soon losing its espiosive sewer umier atmospheric conditions which cemprises'wettin a charge eemprising an exidizing salt he d in a persons oonisiner, with a substantial quensity ef-s hydmesrimnw ceuos liquid more volatile than pentane,

In testimony whereof, I. have iwreunte set my hand at Les Angeies, California, this 2nd day ,of March, 1929.

RQBERT G. WLFF.