US1944910A - Explosive composition and method of making - Google Patents

Description

Patented Jan. 30, 1934 UNITE EXPLOSIVE COMPOSITION AND METHOD or MAKING Clifford A. Woodbury, Media, Pa., assignor to E. I. du Pont cle Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing.

Application May 23, 1931 Serial No. 539,630

14 Claims.

My invention relates to a high explosive composition and more particularly to a high explosive composition from which other explosive compositions of different types and strengths can subsequently be made.

High explosives of different types, as made at the present time, comprise mixtures of a variety of different ingredients. Among the ingredients used are nitroglycerin and similar nitric esters, gelatinizing agents for the nitroglycerin, various oxygen carrying ingredients, such as ammonium nitrate, sodium nitrate, potassium chlorate, etc., absorbents for the nitroglycerin, such as wood pulp, starch, flour, corn meal and other different materials of similar composition, anti-acid materials, such as chalk for neutralizing incipient acidity that may develop, sulphur, sodium chloride and various other materials.

The materials mentioned above are all used for specific reasons and according to well defined principles which are familiar to those skilled in the art. By varying the proportions and kinds of the various ingredients used, it is readily possible to control the strength, density, velocity, sensitiveness, water resistance, fumes and other properties of the explosive to suit the purpose to which the explosive is to be applied According to the ingredients used in dynamites and their properties, various well recognized types of dynamites are produced which are classified by those skilled in the art, into the following general groups:

. Straight dynamites Ammonia dynamites Gelatin dynamites Ammonia gelatins Permissible dynamites It will be seen from the above that there are many types of high explosive compositions and that their properties are the result of formulating the powders according to certain definite and well defined principles.

Dynamite manufacture, at the present time, is carried out in plants of considerable size, and must, of necessity, involve many preliminary operations. Among such operations may be mentioned the preparation and mixing of nitrating acids, the manufacture of ammonium nitrate, the preparation and control of various non-explosive ingredients, including their drying, grinding, and screening, as well as the manufacture of nitroglycerin and the disposal of the nitrating waste acids. The above operations are costly and complicated, and require central manufacturing ouawgor types of dynamites desired. No other method 5 of producing the various explosives required has been possible prior to the present invention.

The manufacture of the finished dynamite at central explosive plants has been necessary because of the fact that it is impossible to transport 55 safely large quantities of nitroglycerin. Nitroglycerin is a necessary ingredient in all the usual dynamite compositions, and is the most hazardous to produce of the various ingredients.

The shipment of nitroglycerin by itself on railroads, for example, is out of the question from a safety point of view.

The transportation of nitroglycerin after its simple absorption in the necessary amount of materials such as wood pulp, is comparatively safe provided the mixture does not contain more than 60 percent of nitroglycerin. 75 percent straight dynamite is manufactured but, for reasons of safety, must be transported by water.

This is necessary because of the possibility of so exudation of nitroglycerin from the absorbent causing a dangerous condition.

It will be readily apparent to one skilled in the art that only a very limited number of different explosives having very limited properties could be manufactured from these high strength straight dynamites. Various high nitroglycerin content gelatins are commonly sold in which the nitroglycerin is fixed by gelatinization with varying amounts of nitrocotton but the proportions usually employed give a gelatin so firm that it cannot subsequently be broken up and mixed with other materials to form a satisfactory dynamite.

I have now discovered a new and improved method for rendering nitroglycerin safe for transportation, at the same time maintaining it in such mixtures as to allow of its subsequent use in explosives. I have found that the use of mixtures of the following compositions gives the desired advantages, and that the heretofore inherout disadvantages are thereby overcome.

In mixtures of the above compositions, a balance is maintained, with increasing nitroglycerin content, between the two mixing materials, nitrono cotton and wood pulp. This is done by increasing the amount of nitrocotton as the nitroglycerin content is increased and the wood pulp content decreased. By proceeding thus, a decrease in the amount of absorbent is compensated for by an increase in viscosity and gelatinization. The increased gelatinization automatically reduces the amount of wood pulp necessary to hold the nitroglycerin securely. The amount of nitrocotton must be so controlled as to produce a product of satisfactory physical characteristics.

The compositions described above are permissible for shipment: They do not allow the exudation of nitroglycerin, and are sufiiciently low in viscosity so that they can subsequently be coinbined with other ingredients to form the different compositions desired.

There are many possible combinations of materials, which are within the scope of my invention. However, I prefer to use as a starting composition, one consisting of per cent nitroglycerin, 1 per cent nitro ott n, 13 per cent wood pulp and l per cent chalk. With the above starting composition, it is possible to manufacture any of the above-mentioned five general classes of explosives. For example, if I wish to manufacture to per cent straight nitroglycerin dynamite, I may use i7 pounds of the above-mentioned starting composition and 53 pounds of non-explosive ingredients consisting of 9 pounds of wood pulp and 2M pounds of sodium nitrate. If I wish to make to per cent straight nitroglycerin gelatin dynamite, I may use 58.9 pounds of the abovementioned. starting mixture, 43.1 pounds of sodi um and 1 pound of corn meal.

The composition may also be any one of those covered by my copending application, Serial No. 539,631, filed May 23, 1931.

From the composition described practically all the standard dynamites can be made when the proper amounts of other readily available materials are mixed with the starting composition. The different compositions can be incorporated in standard mixing equipment and the powders are found to have the properties desired.

The advantages of my new method of compounding high explosive compositions can be readily seen. The new method permits high explosives of all types to be made without the necessity of manufacturing nitroglycerin at the same place. By using this method, it is possible for mixtures containing high percentages of nitroglycerin to be transported safely, and to be mixed elsewhere subsequently with the desired proportions of ingredients available locally. Substantial savings in transportation costs can be thus realized. Other advantages will readily suggest themselves to those skilled in the art.

It is to be understood that various minor changes may be made in the compositions without departing from the spirit of the invention. For example, in place of nitroglycerin alone, this compound may be used mixed with various similar materials such as are frequently used for the depression of its freezing point. Such materials comprise nitrated polymerized glycerin, nitrated sugars, nitroglycol, nitrated chlorhydrins, etc. Similarly, in place of wood pulp, other carbonaceous combustible materials of relatively high absorption value may be used, such as, for example, balsa wood, bagasse pith, and other various pithy materials.

As many apparently widely different embodiments of this invention may be made without departing from the spirit thereof, it is to be understood that I do not limit myself to the foregoing examples or descriptions except as indicated in the following patent claims.

I claim:

1. An explosive composition capable of being subsequently combined with additional ingredients to form various types 'of nitroglycerin high explosives which composition comprises between 75 and percent of at least one liquid nitric ester, between 0.5 and 2.5 per cent of a gelatinizing agent, and between 23.5 and 6.5 per cent of a combustible absorbent material.

2. An explosive composition capable of being subsequently combined with additional ingredients to form various types of nitroglycerin high explosives which composition comprises between 75 and 90 per cent nitroglycerin, between 0.5 and 2.5 per cent of a gelatinizing agent for the nitroglycerin, and between 23.5 and 6.5 per cent of an absorbent material.

3. An explosive composition capable of being subsequently combined with additional ingredients to form various types of nitroglycerin high explosives which composition comprises between 7 5 and 90 per cent nitroglycerin, between 0.5 and 2.5 of a gelatinizing agent, and between 23.5 and 6.5 per cent of a combustible absorbent material.

a. An explosive composition capable of being subsequently combined with additional ingredients to form various types of nitroglycerin high explosives which composition comprises between '75 and 90 per cent nitroglycerin, between 0.5 and 2.5 per cent nitrocotton, and between 23.5 and 6.5 per cent of a combustible absorbent material.

5. An explosive composition capable of being subsequently mixed with additional ingredients to form various types of nitroglycerin high explosives, which composition comprises between 75 and 90 per cent nitroglycerin, between 0.5 and 2.5 per cent nitrocotton, and between 23.5 and 6.5 per cent wood pulp.

6. An explosive composition capable of being subsequently combined with additional ingredients to form various types of nitroglycerin high explosives which composition comprises about 85 per cent nitroglycerin, about 1 per cent nitrocotton, and about 13 per cent combustible absorbent material.

7. An explosive composition capable of being subsequently combined with additional ingredients to form various types of nitroglycerin high explosives, which composition comprises about 85 per cent nitroglycerin, about 1 per cent nitrocotton, about 13 per cent wood pulp, and about 1 per cent chalk.

8. A method of manufacturing a dynamite composition which comprises preparing a substantially unbalanced explosive composition comprising nitroglycerin and less than the normal amount of non-explosive or dope ingredients required to produce a finished dynamite composition, compensating for the decrease in the amount of absorbent by introducing a small amount of nitrocotton so as to' increase the viscosity and gelatinization of the product to hold the nitroglycerin in place against leakage, thereby producing a composition having physical characteristics rendering it safe for handling and transportation, and subsequently combining therewith the dope ingredients to produce a dynamite of lower nitroglycerin content.

9. A method of manufacturing a dynamite composition which comprises preparing a substantially unbalanced explosive composition substantially free of oxygen yielding salts comprising nitroglycerin and less than the normal amount of non-explosive or dope ingredients required to produce a finished dynamite composition, compensating for the decrease in the amount of absorbent by introducing a small amount of nitrocotton so as to increase the viscosity and gelatinization of the product to hold the nitroglycerin in place against leakage, thereby producing a composition having physical characteristics rendering it safe for handling and transportation, and subsequently combining therewith the dope ingredients to produce a dynamite of lower nitroglycerin content.

10. A method of manufacturing a dynamite composition which comprises preparing a substantially unbalanced explosive composition comprising nitroglycerin and less than the normal amount of non-explosive or "dope ingredients required to produce a finished dynamite composition, compensating for the decrease in the amount of absorbent by introducing not more than 2.5 per cent. nitrocotton, thereby producing a composition having physical charactertistics rendering it safe for handling and transportation, and subsequently combining therewith the dope ingredients to produce a dynamite of lower nitroglycerin content.

11. A method of manufacturing a dynamite composition which comprises preparing a substantially unbalanced explosive composition containing substantiallybetween and 90 per cent. of at least one liquid nitric ester, between 0.5

and 2.5 per cent. of a gelatinizing agent for the nitric ester, and between 23.5 and 6.5 per cent. of an absorbent material, thereby making a composition having physical characteristics that render it safe for handling and transportation, and subsequently breaking down the composition and combining therewith the dope" ingredients to produce a dynamite of lower nitroglycerin content.

12. The method of claim 11 in which the combustible absorbent material is a combustible taken from a group consisting of wood pulp, starch, flour, vegetable piths, and a cereal prodnot.

13. A method of manufacturing a dynamite composition which comprises preparing a substantially unbalanuced explosive composition containing substantially between '75 and 90 per cent. nitroglycerin, between 0.5 and 2.5 per cent. of a gelatinizing agent for the nitroglycerin, and between 23.5 and 6.5 per cent. of an absorbent material, thereby making a composition having physical characteristics that render it safe for handling and transportation, and subsequently breaking down the composition and combining therewith the dope ingredients to produce a dynamite of lower nitroglycerin content.

14. The method of claim 13 in which the combustible absorbent material is a combustible taken from a group consisting of wood pulp, starch, flour, vegetable piths, and a cerial product.

CLIFFORD A. WOODIBURY.