US2436002A - Flux-forming fuel and method for thermally working minerals therewith - Google Patents

Description

Feb, 17, 3948. v. c. WILLIAMS FLUX-FORMING FUEL, AND METHOD FOR THERMALLY WORKING MINERALS THEREWITH Filed Dec. 51, 1942 INVENTOR VIRGIL C. WILLIAMS ATTO R N EY Patented Feb. 17, 1948 FLUX-FORMING FUEL AND METHOD FOR THERMALLY WORKING MIN- ERALS THEREWITH Virgil C. Williams, Evanston, Ill., assignor to The Linde Air Products Company, a corporation of Ohio Application December 31, 1942, Serial No. 470,839

Claims. (Cl. 255-13) This invention relates to a flux-forming fuel, and to a method for thermally working mineral and like materials therewith. More particularly, the invention concerns a flux-forming fuel and a process for forming holes in such meltable mineral materials as iron ore, greenstone, and concrete. The present application is a continuationin-part of Patent No. 2,327,482, entitled "Mineral cutting and piercing, issued August 24, 1943, to R. B. Aitchison, C. W. Swartout, and V. C. Williams.

In Patents 2,286,191 and 2,286,192 of R. B. Aitchison et a1. there are disclosed novel processes and apparatus for thermally working mineral materials. as by piercing in them holes for blasting. Either a spalling procedure or a melting procedure may be followed, depending primarily upon the character of the mineral material to be worked. When forming a hole in material such as iron ore, Ely greenstone, or concrete, the melting procedure is followed by applying against the rock an intense oxy-fuel gas flame from a long blowpipe, and-advancing the blowpipe into the rock as material is melted off and a hole is formed. Usually a continuous stream of an unbonded comminuted exothermically oxidizable metallic flux-forming material is carried into the flame by the fuel gas to burn and provide a large amount of heat, as well as to combine with the molten mineral material or slag and increase its fluidity. A pneumatic powder dispenser ordinarily is provided in the fuel gas supply conduit for suspending the powdered material in the gas before it enters the blowpipe.

Among the comminuted metallic flux-forming materials employed have been iron, ferrosilicon,

ferromanganese, zirconium-silicon, silicomanganese, calcium-silicon, and various mixtures of these materials. Sometimes small quantities of preformed fluxes, such as oxides or salts of metals, are mixed with the metallic material for modifying the slag composition and properties. It has been found that most powdered metallic materials of this character do not ignite quickly enough and burn with sufilcient rapidity to give the optimum heating and fluxing effect. Moreover. it has been found that many such powdered materials can not be pneumatically suspended in the conveying gas stream uniformly and with complete dependability because they tend to clog the passages of the powder dispenser, the conduit lead ng to the blowpipe, and the passages of the blowpipe.

Fuels consisting wholly of comminuted or pulverulent aluminum also have been used, but the resulting large quantities of aluminum oxide have been found to unite with most molten mineral materials to form a pasty viscous slag which can be removed in the fluid condition only with great difliculty.

One of the objects of the present invention is the provision of an unbonded novel comminuted flux-forming fuel characterized by its greatly improvedignitability and combustibility. and by its improved flow characteristics. Another obiect is the provision of such a flux-forming fuel utilizing pulverulent aluminum with other pulverulent metallic materials to impart the foregoing valuable properties, Still another object is the provision of such a fuel using such a small proportion of pulverulent aluminum that the cost of the fuel is low, yet important improvements in the foregoing properties are obtained. Other objects are the provision of a novel and improved method for thermally working mineral and like materials-rapidly and continuously using a powdered fuel containing aluminum: the provision of such a method particularly adapted for the thermal piercing of holes in meltable mineral materials and-the like; and the provision of such a method utilizing an oxy-fuel gas flame and a novel pulverulent flux-forming fuel containing small quantities of aluminum powder to increase the ignitability and combustibility of the chief constituent of the fuel..

The above and other objects...and the novel features of the invention, will become apparent from the following description having reference to the accompanying drawing, wherein:

Fig. 1 is a side elevational view. partly broken away and in section, showing typical apparatus for performing the process of the invention:

Fig. 2 is a longitudinal sectional view of a blowpipe for performing the process;

Fig. 3 is a view of the left end of the blowpipe shown in Fig. 2;.and

Fig. 4 is a cross-sectional view taken on the line 44 of Fig. 2.

The flux-forming fuel of the present invention comprises a comminuted unbonded intimate mixture of pulverulent aluminum with part cles of different pulverulent combustible metallic material having by itself relatively poor flowability, ignitability, and combustibil tv compared with the mixture. Among the metallic materials used with aluminum have been iron. and the alloys ferrosilicon, ferroman anese. zirconium-silicon, silicomanganese, calcium-silicon, and various mixtures of thesematerials in a pulverulent state.

It has been found that pulverulent aluminum 3 offers important advantages in such a mixture when used in relatively small amounts ranging from 0.1% to 10% by weight of the mixture, and preferably from 0.1% to 5%, the remainder being substantially all the particles of the other metallic 5 materiall- Surprisingly:- aluminum powder" has" been found to provide a thin adherent coating to particles of such other materials and. to function as" a solid or dry lubricant facilitating the-rfree'movee; c ment of the particles over and; pastzfeachiother. and through the passages for conveying the pow der mixture to the point ofwuse. As. a result, powdered metals and compoundsi.;:carr.be'corr veyed by a gas stream in much more constant" proportions and with much less likelihood of clogging the passages than: heretoforen- More-r over, the coating of aluminum has relatively good. ignitability and burns rapidly, thus acting as a fuse. whereby the ignition. and burning of, the 2 underlying i irorr a other-metallic particle's in oxygemare f acilitated. Excellent lubricating and heat promoting effects era-obtained by the use in the'mixture of around I 'by-weig'ht' off aluminum powder .based upon thevtotal weight of-the mixture.

It is; "noteworthyfthat the rate ofthermall'y Working aimineralmasaby ther 'method-"fto'-be-describedxm'or "iniidetailhereinafter: IISlIlgftYlfG comminute'd' flux=forming:fu-el "ofthe invention; isconsi'derably increased by the-importantproperties 'oft'the HOVG'I".fll81jlIfiXfilllf-f' Furthermore, excellent heat promotin ijand-powder flowcharacteristics are obtained "more" economically-with. small amounts of aluminum powder-than where larger quantities 'of expensive'aluminum powder are. employed becauseithese characteristics do not A increase proportionately tothe increased amount ofal'uminuzm powderemployed above & 10j%.f i iell Sometimes. smallamounts of preformed fluxes: such as 'pulverulent oXides orrsaltSimay also-be usedf'jn a minor proportion; in "thecomrnin'uted iuelimixture without? reducing-ethe advantages 5 attending the presence of"aluminumf" powder; Moreover, the .novel' properties: 'ofithe powdered fuelfof .the invention" are obtain'edieven though the, size; of j the. aluminum:particles'tbe= varied widely. For instance, fuels contalningal'uminum particles.varying between'MO mesh-andflObmesh Tyler have been used"successfullyfor performing the ,7 method "of" the invention? lii -generalit is best for the; aluminum-to he more finely divided than thesother"powdered:metallic;material with which'it is mixed.

The novel. method for thermallyworking mineraliandflikemasses;'accordiiigtd'thepresent invention, comprises 'separating material from such amass. by applying; an*intense'-,oxy-1fu'el flame to a portionof the mass while-introducing continuously into.v the flame a comminuted unbonded fiux-formingfuelpf thetype'described previously herein. The. aluminum powder] is usedjin every: :case, but? the naturaofthe other component; or, :components of the mixture be. variedfiin "accordance with. the "naturepfthe mass .to be. workediandthe character 'ofi'thersla desired;

Theslag; may .be .removedin either thei'liquid or solidflicondition" by 'the "gaseous productsof 7 combustion; often assisted by'an" auxiliary ejecti'onfluid; Bemoval'pfthe slag inthesolid'fcmtrditibin. is accomplishedby fi'rst quenehingitthe slaggwith, water.:.upon which. iti'either. disinteigrates spontaneously or may be disintegrated passes to the-blowpipe l mechanically. The process is particularly applicable to the piercing of deep blasting holes of circular cross-section extending straight into a mass of mineral material. However, the principles of the invention also may be applied to the production-30f other hol'es-imthenatunesfofigrooves or cutsz' Typical apparatus for performing the process of the invention is shown in Fig. 1 of the drawings.asr-appliedetothe piercing of a deep blasting hole ircularicnoss-section in a mass of mineral material-1 I L; Aifil'ong oxy-acetylene blowpipe l3 applies anintense heating flame against the forward-:face"o'*a,,hb1e 15 in the mass ll, thereby causing materiala'toseparate from the mass as a molten slag. The separated slag is removed from the-holeibyzthesegaseous products of combustion augmented by streams of ejection fluid discharged from the blowpipe l3 near its forward end. As the hole becomes deeper the blowpipe is advanced steadily 'to *heat and separatemamar 'f-rom each newly exposed area-at the far ward-"face-pf the h'ole.-- Gaseous 'oxygen' and acetylene are supplied" tome bloWpipe'l- S through the hoses l-Fand a? respectivelw leadihg fiom suitable sources of suppw Powde'red flux ferming uel' 'iscarried in 'sus-j pensiorr in=one"of thegasese prefrably the acetyl ene." The 'poWd'eF-is i trodu'ced 'intofthe flo'wig streamof acetylene by a pneumaticpowder d f penser 20 connected to a suitable source of acetye leneysuch as a cylinder; by a-hose 22 in wl'1ich a pressure regulatorfi t is -=int;er-posed The= pow derela-den acetylene f-rom the dispensen 2-11 their which 'is*interposed a back pressure or -checl valve-2 h- V Thepowder dispenser Zll mayheofitlie type fully-- described in Patent N'a- 2;286, 7-76 *is'sued June'lfif1942fto-VJCLWilliams eta-II T e back pressure valve 21 may be constructed the manner described in-Patent Nd: 2}286;84I;1-i's sued Jflne16f1942, to-G.'--H". Smit I V Auxiliarydebris=ejection airowwatretfeame for discharge from' theblowpipei3" adjacent; to its? forward end may-be= introduced i'n'to'==--th'e blowpipeithrougha hose Water ior' coolihg the blowpipe mayenterthroughth hose ifi and leavethrougnthe -hose V Onetypeof -'blowpipe' for*performing-the proc esspi theiiiventiomisshownin detall in'Flgs '2 3;- andg lx Eowder laden acetylene-from the-com duit I 9' enters-a' centrartube -29 iand*is discharged centrally at. the forward endchalic -blowpipe: Oxygen from the conduit" ll passes forwardly through; a --conduit'-3"l surronnding' the central tube 29',"and is'thencedi'schargedfrbnr he'tip flr of "the:blowpipe through aseries 'of fiischarge passages "3 fi-l-iarranged on" an annular 'zone sur rounding the" 'centralf'tube-2*9' andconverging'fdr wardlytowardtheilatter 'and toward -ones an; other." The? oxygen" and powder-eladen acetylene thus: mix" outsidethe :bIowpi-pe toform-za flame ofthe'diffu'sion type, which i'sfpeculiarly resistant to, 'flashbacksz" OXygen""is*-'suppl-ied"' ifiwuffideht volume to tburn completely botli?-the acetylene and the powderedfuel? AIY'BjBCtiOn fluid*"such'--as"air"orwater fibm the 'hose'23i 'pass'es forwardly. througl izi'a-"conduit 3]surrounding the conduit 3 fyjandls discharged in: streams from we tip 13 3 toward t the rear'pf the blowpipe through-aserl'es of annularly' ar ranged rearwardly and outwardly incliiied-'passages orzp orts "3 9i'spa'ced' a shcrti distance'frbm the front'of the "blowpipe? x.fthrough the condiiit 15? 'x fp -f' b iin g the blowpipefa stream of water is introduced through the hose 25 and flows for- "ward to the-rear end of the tip 33 through the outside casing 41. The water then passes around the forward end of a bafiie 43 and returns to the rear of the blowpipe, .from which it is discharged through the outlet hose 21.

:; A-few examples of-..the method of the inven tion are given below.

Holes totaling 9% ft. in depth were pierced with an "oxy-acetylene flame at an average rate of li illiinches per minute-in Soudan iron ore (a very denseiiron oxide) using a comminuted flux- -formingffuelmixture consisting by weight 90% of-pulverulent ferromanganese and 10% of pul- 'verulent aluminum, suspended in acetylene gas.

Holes totaling 184 ft.in depth were pierced in Soudan iron ore using a comminuted flux con- "sisting by weight 66.6% of pulverulent ferro of pulverulent zirconiumsilicon, and '7% of pulverulent aluminum.

1 A hole 43%; inches in depth was pierced in manganese; 26.4%

Soudan iron ore --using a flux-forming comusinga flux-forming comminuted fuel mixture consisting by weight 95% of iron powder and 5% of aluminum powder.

Deep holes were pierced in a large block of concrete using a flux-forming comminuted fuel mixture consisting by weight 99% of steel powder and 1% of aluminum powder. Deep holes also were pierced in the same material using a comminuted flux consisting by weight 90% of steel powder and of aluminum powder.

It is to be understood that the comminuted or pulverulent flux-forming fuel, and the process of the invention, are capable of modification within the scope of the invention as defined by the claims attached hereto.

I claim:

1. A flux-forming fuel consisting of a comminuted unbonded intimate mixture of aluminum particles with particles of at least one different combustible metallic material having relatively poor fiowability and ignitability selected from the group consisting of iron, ferrosilicon, ferromanganese, zirconium-silicon, silicomanganese, and calcium-silicon, the aluminum par-- ticles being 0.1% to 10% of the weight of said mixture and the remainder being substantially all particles of said different metallic material.

2. A flux-forming fuel consisting of a comminuted unbonded intimate mixture of aluminum particles with other combustible particles of different metallic material having relatively poor flowability and ignitability, the aluminum particles being 0.1 to 5% of the weight of said mixture and the remainder being substantially all particles of said different metallic material.

3. A flux-forming fuel consisting of a pulverulent unbonded intimate mixture of aluminum powder, with powder of diflerent combustible metallic material having relatively poor flowability and ignitability, the aluminum powder being about 1% by weight of said mixture and the remainder being substantially all powder of said diflerent metallic material.

6 4. flux-forming fuel useful in'" thermally working mineral and mineral-like'masses, said fuel consisting of a comminuted unbondedmixture of particles of iron and of aluminum-"the -aluminum particles being 0.1% to 10% of the weight of said mixture. and the remainder being substantially all iron particles. f 1

5. In a process for thermally working mineral and like masses comprising separating and removing material from such a mass by applying an oxy-fuel flame to a portion thereof while introducingi-nto such flame a comminuted flux- Iminuted' fuel mixture consisting by weight 90% of pulverulent iron and 10% of pulverulent forming fuel, the improvement which consists in introducing said flux-forming fuel as a flowing stream of a comminuted unbonded intimate mixture of pulverulent aluminum, with particles "or at least one combustible metallic'material having relatively poor flowability and ignitability lected from the-group consisting of-iron', ferro- 20 silicon, ferrcmanganese, zirconium-silicon; silicomanganese, and calcium-silicon. the pulverulent 4 aluminum being 0 .l% to 10%- y weight'of-"said mixture and 'theremainder being substantially all said particles of different metallic material, whereby a comminuted flux-forming fuelhaving improved flowability and ignitability is provided and the mineral working operation is expedited.

6. In a process for thermally working mineral and like masses comprising separating and removing material from such a mass by applying an oxy-fuel flame to a portion thereof while introducing into such flame a comminuted fluxforming. fuel, the improvement which consists in introducing said flux-forming fuel as a flowing stream of a comminuted unbonded intimate mixture of pulverulent aluminum. with particles of different combu tible metallic material having relatively poor flowability and ignitability, the pulverulent aluminum be ng 0.1% to 5% by weight of said mixture and the remainder be-- ing substantially all said particles of difierent metallic material, whereby a comminuted fluxforming fuel having improved flowability and ignitability is provided and the mineral working operation is expedited.

7. In a process for thermally working mineral and like masses comprising separating and removing material from such a mass by applying an oxy-fuel flame to a portion thereof while introducing into such flame a comminuted fluxforming fuel, the improvement which consists in introducing said flux-forming fuel as a flowing stream of a comminuted unbonded intimate mixture of aluminum powder, with particles of different combustible metallic material having relatively poor flowability and ignitability. the aluminum powder being about 1% of the weight of saidv mixture and the remainder being substantially all said particles of d fferent metallic mater al, whereby a comm nuted flux-forming fuel having improved flowabillty and ignitability is provided and the mineral working operation is expedited.

8. In a process for thermally working mineral and like masses comprising separating and removing material from such a mass by applying an oxy-fuel flame to a portion thereof while introducing into such flame a comminuted flux-forming fuel, the improvement wh ch consists in introducing said flux-forming fuel as a flowing stream of a comminuted unbonded mixture of particles of iron and of aluminum, the aluminum particles being 0.1% to 10% by weight of said m xture and the remainder being substantially all particles of iron, whereby a comminuted flux-

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