US1318709A - of london - Google Patents

Description

UNITED STATES PATENT OFFICE.

CLAUDE THEODORE JAMES V AUTIN, OF LONDON, ENGLAND, ASSIGNOR 'IO THEBMALLOY LIMITED, OF LONDON, ENGLAND.

' IGNITIBIiE METALLIC MIXTURE AN D PROCESS FOR PREPARING THE SAME.

No Drawing.

To all whom it may concern:

Be it known that I, CLAUDE THEODORE JAMEs VAUTIN, a subject of the King of England, residing in London, England, {have invented a certain new and useful Improved Ignitible Metallic Mixture and Process for Preparing the Same, of which the following is a specification.

This invention relatesto ignitible metallic \mixtures, such for example as that commonly known wherein powdered aluminium and powdered iron oxid are intimately mixed together with the result that, if a sufficiently high temperature be created 10- cally in the powder, combustion will proceed of itself under the oxidationof the aluminium and the reduction of the iron.

Such materials as heretofore prepared 4 and used have given rise to difficulty under certain conditions of employment, by reason of the two constituents 'becoming more or less separated by segregation. One method of overcoming this difficulty has been tried by. which a combining material was added to the powder, which combining material was inert and was added in the least possible proportions so as to interfere as little as possible with the normal chemical and heat reactions. Nevertheless the addition of such a binding material slightly delayed thereaction, and when the mixture was highly compressed to form a solid substance, the latterwas not so easy to ignite as the loose powder without thebinding material.

It is the main object of the present invention to provide a process for preparing an ignitible metallic mixture in the form of a solid body which shall be superior to that just above described.

Various pulverized mixtures of one or more heavy or light metallic powders with sulfur alone or a sulfur compound alone, have heretofore been proposed for various purposes. These mixtures, however, were loose and did not constitute a solid body such as that provided by the process according to my invention; also the generation of heat by these loose powders is apparently so slow that they could not be used for incendiary bombs or like purposes, and I make .no claim to any such loose mixtures.

It has also been proposed to employ in the form of a solid body a mixture of aluminium with a sulfur-containing compound for the manufacture of metal castings or Specification of Letters Patent.

Patented Oct. 14, 1919.

Application filed April 10,1919. Serial No. 289,177.

, metallic mixture consists in heating sulfur tea temperature not exceeding 200 C. until 1t, becomes plastic, and adding thereto with constant stirring a finely divided metallic substance, for example a finely divided metal such as aluminium. Conveniently, a plastic mass obtained as ust described or prepared by heating a mixture of sulfur and finely divided metal to the said temperature with constant stirring is cast into the desired shape while still plastic and allowed to set hard. If desired, oxid of iron may be mixed with the finely divided metal before the mixture is heated. Further, according to the invention, an ignitible body in solid form may be made by a process consisting in mixing a metallic sulfid, for example iron pyrites, in the form of a fine powder, with finely divided sulfur in the proportion of from 15% to 50% by weight of the said sulfid, heating the mixture of sulfur and sulfid to a temperature below the burning point of sulfur (for example not exceeding 200 C.) with constant stirring until the mixture becomes a plastic mass, subsequently allowing the mass to become cool and hard, reducing the massto powder and employing the powder thus obtained in substitution for or for part of the sulfur in the process described above in the two preceding paragraphs.

' The free sulfur employed according to the present invention has the advantage of being itself combustible and, further, of readily forming metallic sulfids with an exothermic reaction, and in the product resulting from the process according to the invention itis present in such form as to constitute both a binding material and a chemically-reacting material. In one form of the product the sulfur is present in combining proportion with a metal or in more than such proportion. The combining material in the product may comprise a metallic sulfid and sulfur intimately mixed. together, the sulfid being preferably a natural sulfid; for example, when iron is used as the metal, iron pyrites is the preferred sulfid.

The proportion of sulfur employed will the sulfur content the less plastic and the more fluid is the result when hot.

By way of example to' illustrate the nature of the present invention, thefollowing mixtures may be cited Mixture A )-.A mixture of ahtmimlum powder and -suZfu1'.F or the aluminium powder ordinary aluminium scrap containmg excellent for-such purposes as incendiing about 87% of aluminiumand 7 %8% of zinc may be employed the powder beingreduced to pass a QO-mesh screen or finer. For the sulfur ordinary commercial finelydivided sulfur of 97% purity at least is employed.

Thesematerials are so mixed and proportioned that the materials combine to give A1 8 and ZnS with substantially no excess of sulfur.

This material in itself constitutes an excellent ignitible mixture provided the local temperature to ignite it be high enough. 'On the other hand, the temperature of the mix ture can be raised to the'ignition tempera- 'ture of sulfur in air without combination ordinarily known as alumino-thermic mixture consisting of a -mixture of powdered aluminium with the usual zinc adulteration when scrap aluminium is used and ferrosoferric oxid in proportions such that the final result of the reaction is a mixture of A1 0 and Zn() and iron.

Here again alternatively, pure aluminium powder free from zinc may be used. giving the commonly known mixture. Either the above specified alumino-thermic mixture or the said known mixture is hereinafter described as Mixture Mimi-are (0).This mixture consists of one part of Mixture (A) and two parts of Mixture (B). The calculated proportions of the ingredients for this double mixture are intimately mixed and then heated to a temperature not exceeding 200 C. with constant stirring until the contents become plastic.

The. plastic mass obtained with the hot sulfur .in any of the above mixturesmay be cast or rammed direct into bomb-cases or moldsas desired. In a shorttime, for ex- -of (A) and nine of (B).

i'than. is'i'the resultant product .from ,Mixture (B) alone. This extrafiuidity is frequently of considerable value.

Whereas the Mixture (C) iscited as beary bombs, for other purposes the proporsay equal quantities of each down to one Another mode of carrying out the present invention is now described by way of example. Iron pyrites is groundto an impalpable powder and mixed with 40% of its own weight of sulfur. The mixture is then heated with constant stirringto about 190 C. until the wholebecomes ahomogeneous plastic mass. This is then poured out and allowed to become cool and set hard. The

hard-mass 1 is then crushed and ground to a powder and is then employed exactly as,is

the sul ur in the mixtures? above described. .Alternatively it may be used to replace part only, instead of the whole, of the sulfur in .those mixtures.

The mixture of sulfur and metallic sulfid 'is somewhat safer to, handle during the process of manufacture than is the mixture wherein sulfur alone is employed as the binding material without admixture thereto of a metallic sulfid. The mixture thus provided has other qualities which constitute it a desirable alternative to, or addition to, the sulfur employed in the manner described above.

This invention is not limited to the e ployment of sulfur or sulfur and metallic sulfid in mixtures of only the precise char- ;acter quoted above, but extends to the use ofthese materials as a binding and combining material in any solid ignitible metallic mixture.

What I claim as my invention and desire to secure by Letters Patent is 1. A process for preparing an ignitible solid body consistinginmixing a finely divided metal and free sulfur in combining proportions with one another together with a finely divided metal and an oxid, which second said metaland oxid together constitute an ignitible mixture, in heating the mixture to a temperature not exceeding 200 'tions of (A) and (B) may be varied from C. with constant stirring until the mixture becomes a plastic mass, andin leavingthe mass to set into a solid condition.

2. A process for preparing an ignitible solid body consisting in mixing a finely divided metal and free sulfur 'in....co g proportions with-one another together with an oxygen compound-=. ;of another metal in powdered form, in heating themixture to a temperature not exceeding 200 C. with constant stirring until the mixture becomes a plastic mass and in leaving the mass to setv into a solid condition.

3. A process for preparing an ignitible solid body consisting in mixing finely di vided aluminium, an oxid of iron, and free sulfur in combining proportions with one another, in heating the mixture to a temperature not exceeding 200 C. with constant stirring until the mixture becomes a plastic mass, and in leaving the mass to set into a solid condition. A

4. A process for preparing an ignitible solid body consisting in mixing a metallic sulfid in the form of a fine powder with finely divided sulfur in the'proportion of from 15% to 50% by weight of the said sulfid, heating the mixture'to a temperature not exceeding 200 C. with constant stirring until it becomesga plastic mass, and adding thereto with constant stirring a finely divided metallic substance.

51 A process for preparing an ignitible solid body consisting in grinding a metallic sulfid to a fine powder, mixing finely divided sulfur therewith in the proportion of from 15% to 50% by weight of the said sulfid, subsequently heating the mixture to a temperature not exceeding 200 C. with constant stirring until it becomes a plastic mass, leaving the mass to become cool and hard, reducing the mass to powder, mixing the powder thus obtained with powdered sulfur, heating the mixed powders to a temperature not exceeding 200 C. until it becomes a plastic mass, and adding thereto with constant stirring a finely divided metallic substance.

6. A process for preparing an ignitible solid body consisting in mixing ametallic sulfid in the form of a fine powder with finely divided sulfur in the proportion of from 15% to 50% by weight of the said sulfid, heating the mixture to a temperature not exceeding 200 C. with constant stirring until it becomes aiplastic mass, leaving the mass to become cool and-hard, reducing'the mass to powder, mixing the powder thusobtained with a finely divided metal and. heating the mixed powders to a temperature not exceeding 200 C. with constant stirring until the mixture becomes a plastic mass, and casting the said mass into the desired shape while stillplastic and permitting it to set.

7. A process for preparing an ignitible solid body consisting in grinding ametallic sulfid to a fine powder, mixing finely-die vided sulfur therewith in the proportion of from 15% to 50% by weight of the said sulfid, subsequently heating the mixture toa temperature not exceeding 200 C. with constant stirring until it becomes a plastic mass, leaving the mass to become cool and -haird',freducing. the mass to powder; mixing sulfur and finely divided aluminium, heating the mixed powders to a temperature not exceeding 200 C. with constant stirring until the mixture becomes a plastic mass, and casting the mass thus obtained into the desired shape while still plastic and permitting it to set.

81A process for preparing an ignitible solid body consisting in-mixing a metallic sulfid in the form of a fine powder with finely divided sulfur in the proportion of from 15% to 50% by weight of the said sulfid, heating the mixture to a temperature not exceeding 200 C. with constant stirring until it becomes a plastic mass, leaving the 'mass to become cool and hard, reducing the 7 mass to powder, mixing the powder thus obtained with a finely divided metal in combining proportions with one another together with a finely divided metal and an oxid, which second said metal and oxid together constitute an ignitible mixture, heating the mixture thus obtained to a temperature not exceeding 200 C. with constant stirring .thep'owder thus obtained with powdered I until the mixture becomes a plastic mass, and

' leaving the mass thus obtained to set into a solid condition.

9. A rocess for preparing an ignitible solid bo y consisting in mixing a metallic sulfid in the form of a fine powder with finely divided sulfur in the proportion of from 15% to 50% by weight of the said sulfid, heating the mixture to a temperature not exceeding 200 C. with constant stirring until it becomes a plastic mass, leaving the mass to, become cool and hard, reducing the mass to powder, mixin the powder thus obtained together with finely divided aluminium, an oxid of iron and powdered sulfur in combining proportions with one another, heating the mixture to a temperature not exceeding 200 C. with constant stirring until it becomes a plastic mass, and leaving the mass to set into a solid condition.

I form of a compact solid body consisting of free: sulfur, finely divided aluminium, and

powdered iron pyrites.

' 12. An ignitible metallic mixture in the form of a compact solid body consisting of a mixture of finely divided aluminium, free sulfur and an oxygen compound of iron in powdered form.

13. An ignitible metallic mixture in the form of a compact solid body consisting of finely divided aluminium, free sulfur,-a free metallic sulfid, and an oxid of iron in pow-' dered form. r

1 1. A process for preparing an lgnitible metallic mixture in solid form, consisting in heating a finely ground metallic sulfid, sulfur and a metallic substance to a temperature not exceeding 200 (3., with constant stirring until the mixture becomes a plastic mass, and then permitting the mixture 15. A process for preparing an ignitible metallic mixture in solid 'form, consisting in heating finely ground iron pyrites, sulfur and a finely divided substance to a temperature not exceeding 200 C., with constant stirring until the mixture becomes a plastic mass, and then permitting said mixture to set.

In testimony whereof I aflix my signature.

CLAUDE THEODORE JAMES VAU'IIN.