US1916078A - Explosive - Google Patents

Description

' Patented June 27, 1933 EXPLOSIVE I invention relates to explosives and more particularly explosives of the nitro ;.glycerine type.

In the ammonium' nit r'ate class sible explosives of the above type, which are used mainly in gaseous and dusty coal mines,

only a comparatively low percentage ofnitroglycerine or its modificationscan beused,

and this lovrgpercentage of-nitroglycerineror its modifications, Inalres theinitiation and propagation s'ensitiveness of; this type-of, ex-

V. plosivecomparatively low,, especially after storage. g For :example, the upper vlimit of 12% and'usually is 10%. v a ,7

I: 'Emfther,;while for-,yarious reasons, a low density explosive is desired in some tcoal mi ing 291 513 03 h ne al-mi alumnusn y. n me y by ne e e n h nitroglycerine in such explosives is generally ,amount of carbonaceous material, cannot be jutilized with .this typegof explosive for the in. terms sot ethev number of i '1 A x8 carf reason. that I a limit is reached-such as from 10 to 12% of carbonaceous material beyond which; a -I'urther increase interferes with the .sensitiyenfessoftheexplosivess This maybe defined in another waye Density as applied to mining, explosives is ordinarily expressed tridges in lbs, of the" finished explosive ,and; is dependent gof course on the choice of ingredients, especially of the "carbonaceous I material, and on the; manner in which} the x p siv s. a M d l-0n pa t paper*cartrjidges ordinarily useds exp Q i n rma y 1' u e f r, m ns, s

lating the choice and quantity ofingredients nable s gaj maximum cartridge count of between 17 5 and 180 to be attained. -However,

It would be of advantage to overcome this v higher cartridge'count is. often desired and if this is attempted by the ordinary methods, the results are insensitive explosives which are a menace to safety and efliciency of blast- I The use of sodium nitrate in explosive com-' positions has been somewhat limited due to its well known sluggish character inherent in its property of releasing its oxygen slowly.

sluggishness as this would increase the initiation and propagation sensitiveness and Application 'filed July 10,

1928. SerialNo; 991,694. bring aboutfmore eifici'ent and safer blasting espec ally -1n those cases where, due to pe- CUl1&I";CQIld1l'/].OI1S, as in coalmining, eXplo 'sives of low ,nitroglycerine zcontentlwe'r'e heretofore 1 considered sate, other ,va ieties being, dangerous in ,suchlnstances. 'Recent suggestions in the PILOI aIU tO utilize sodium nitrate havebeen'tiedup with a simultaneous incorporationof ammonium nitrate as the principal: impregnating agent "as ,where can bonaceous material ;has}been impregnated with, ammonium nitrate prior to its admixture; with sodium nitrate, .or. where adhesive blends of ammonium nitrate and sodium ni-- trate arefirst prepared. But it will be noted that these prior art suggestions are directed not to nitroglycerine type explosives, since in the'first example referred toabove no nitroglycerine was used,,while in the case of the adhesive blendscompositioma. relatively 7 low percentage of nitrog1ycerinenot over ,5 %-5-was used, which is is customary with lower type of explosives in which this-low percentage oi nitroglycerine is used as sensiz izing ingredient but :not as the principal explosive'ingredientf Among the objects and present invention, ,is the production of exadvantages of the plosives of thenitroglycerine type of rela tively low densityor high cartridge count, which are sensitive, safe and efiicient. iAnd more particularlyan object of the present=---invention"istheproduction of explosives otthevcharacter set forth above wherein -a--low density is obtainable without .runfavorablywaffectingthe:sensitiveness of the nesplos v s P duc nawrda e w h i invention.v v

Other and further objects and advantages will appear from the more detailed description set forth below, it being understood however that this more detailed description is given by way of illustration and not by way of limitatiomsince various changes may be made therein by those skilled in the art without departing from the scope and spirit of this invention as herein set forth.

It has now been found that if the sodium nitrate is incorporated into the cells of the carbonaceous material and an explosive be-1 made including, in its composition, .a sufficient amount of nitroglycerine, or its modifications, to act as the principal detonating and sensitizing agent, satisfactory explosives of the nitroglycerine type are obtainable,

and the prior'artdificultiesheretofore e11 countered are eliminated.

. To obtain-the desired incorporation of the carbonaceous material With sodium nitrate,

the carbonaceous material may, be mixed with Water and then'sodiu mnitrate added causing it to be dissolved 'in'the wat ,ithe

solution to be absorbed by the carbonaceous material, and the surplus water subsequently evaporated. Or the sodium nitrate may first be dissolved in thewater, the carbonaceous material then mixed with the solution in or der to absorb said solution, and then the excess jwater evaporated therefrom." Or if de sired, a solution of sodium nitrate may :be sprayed u'pon the desired carbonaceous material in a closed vessel. in the' presence of por'ated with sodium nitrate in a manner such "asthat set'forth above and containing 30% high pressure steam' (say about 100'poun'd. pressure), andthe pressurefthen released so that the resultant expansion bursts the cells of the carbonaceous'material and the sodium nitrate "is deposited Within the material.

"Ofco'urse any other desirable method of impregnatingthe carbonaceous material with the sodium nitrate may be utilized. 'The proportion'of sodiu'm'nitrate to the material 'tobe treated is-variable depending on the density desired in the produc '1 Thelfollovving example Will serve as an illustration of a'method' of making an explosive in accordancewith the present invention. "The carbonaceous material incoro'f so'dium nitrate to 7 0 of the carbonaceous material, the carbonaceous material in this e'xample'desirably being of lo vves tavaili able density is utilized in a composition con- This admixture of inaar iaiusia the lowest available densitycarbonaceousmaterial,

.claim ,oflow density should, be employed. Balsa Wood may be desirably used in this connection, but 'theinvention is not limited toa certain kind of carbonaceous material as the treatment hereinabove set forth can be. applied to agreat variety of such'materials hav istics. I I a I A Assetforth above, nitroglycerine or its modifications may be used in making the eX- plosives referred 'to,'-an'd these modifications include nitrated solutions of sugar in glycerine, nitrated mixtures of glycerine and glycol, or glycerine and polyglycerine, or glycerine and chlorhyd'rirn'etc.

' In the preferredexplosives made inaccordance vvith-this invention, the amounts of nitroglycerine fall below 8%. V 1 V I .Having thus set forth my invention, LI

1; In a processiof making explosives ,'the

or its .modificationshould not h 1g various densities and other character-" steps 'of mixing" a sodium nitrate solution r,

with carbonaceous material under pressure, and'then releasing the. pressure whereby the sodium nitrate is deposited Within" the cells of the carbonaceous material;

2. In a process of making explosives,

tvherein sodium nitrate solution and carbonaceous materlal are maintained under pressure, the step of releasing the pressure "so that the sodium nitrate is deposited Within the cells of the carbonaceous material.

" 3.In a processor making explosives, the steps of mixing a solution of a salt used in explosive compositions with carbonaceous material under pressure, and then releasing the pressure Whereby'th'esalt is deposited..,

Within the cells of the carbonaceous materiaL' 7 r p BERT SCHLESS.