US2405278A - Ferroalloy briquette and manufacture of same - Google Patents

Description

Patented Aug. 6, 1946 FERROALLOY BRIQUETTE AND MANUFAC- TUBE OF SAME Galbert L. Vance, Zanesville, Ohio, assignor'to Ohio Ferro-Alloys Corporation, Canton, Ohio, a

corporation of Ohio No Drawing.

7 Claims.

The invention relates to briquettes of metals or ferro alloys for use as additions, deoxidizers, and the like, in the making of iron and steel, as Well as to th manufacture of such briquettes.

It is customary in the manufacture of iron and steel to make additions of various metals or ferro alloys such as chromium, silicon, manganese, phosphorus, and the like, to the charge or melt, either as alloys or deoxidizers.

In order to producethe desired results it is necessary that a definite quantity of the desired metal product or ferro alloy be added to the charge or melt and it is therefore necessary that each piece or lump of the metal or ferro alloy addition will have a definite metallic content.

To this end it has long been common ractice to form briquettes of a definite known weight of the desired metal or ferro alloy, in finely divided form, mixed with a binder such as Portland cement, clay, lime or similar materia1.-

The use of. pitch, tar, or a mixture thereof, as a binder in the production of briquettes of various materials is not new, but to the best of my knowledge neither. of these .m'aterials has ever been actually'used as a binderfor briquettesof metals or ferro alloys that are subjected to temperatures higher than the melting or fusion point of the pitch ortar, and it has been generally believed by the steel industry that pitch or tar. do not form suitable binding agents for such use because .of the erroneous belief that they would immediately burn away in the furnace Permitting the briquettes to disintegrate and exposing the readily oxidizable alloys to the oxidizing flames of the furnace so that they are lost in whole or at least in part. f

As an example of the erroneous belief that pitch or tar is not a suitable binder for ferro alloy briquettes attention iscalled to Greiner PatentNo. 1,551,554 of September 1, 1925, for a Process for smelting iron alloys.

Pitch or tar were not regarded as suitable ma- Application December 11, 1943, Serial No. 513,953

Another object is the formation of a, briquette of such metalliferousproducts bound together with pitch or tar under extreme pressure.

A still further object is to provide a method of producing a briquette of this character by mixing ferro alloy material with a small amount of hot pitch or tar and subjecting the same to a suitable pressure to form a briquette.

Still another object of the invention is the provision of a ferro-alloy briquette for use as a furnace addition, which comprises ferro-alloy fragments bound together into a briquette with a binder of tar or pitch which is reinforced by small paper strips, leather shavings or the like, so that the briquette may withstand rough handling at low temperatures.

The above objects, together with others apparent to those skilled in the art, or which may be later referred to, may be attained-by carrying out the invention in the manner hereinafter described in detail.

In carrying out the invention to produce the briquettes from any desired ferro alloy such as terials for binding ferro-alloy briquettes as it was believed that they wouldimmediately burn away in the furnace and thus would not protect the alloys against the hot air in the furnace.

I have found by actual experience however that such theories were erroneousand that pitch or tar is not only a suitable binding agent but that briquettes of a mixture of ferro-alloy fragments and pitch or tar, formed under sufiicient pressure, give very satisfactory results.

It is therefore the object of the present invention to provide a briquette for furnace additions composed of one or more ferro alloys in finely.

' silicon, manganese, chromium, phosphorus, or the like, the desired alloy or alloys may be in small pieces, or in finely divided condition, or a mixture of the two. To this I add a small amount, usually about 3 to 5 per cent by weight of pitch or tar or a mixture of the two, preferably having a high melting point, and preferably hot. I

The ferro alloy and binder are intermixed and may be placed in a mold, of suitable size and shape to produce the briquette desired and subjectedto extreme pressure, preferably about two tons per square inch or the briquette may be formed in an extruding press with less pressure.

Briquettes made in this manner have suflicient strength ,to withstand severe abuse at normal, and at even higher, handling and transportation temperatures. However, at temperatures well below freezing such briquettes may lose a portion of their strength.

1 Therefore, in cases where severe abuse is called for at low'temperatures the briquettes can be reinforced by incorporating small strips of heavy paper such as wrapping paper, leather shavings, or the like, during the binding or briquette forming stage. .Thesestrips of paper or leather act like reinforcing rods in a concrete structure and sufficiently strengthen the briquettes to permit rough handling of the same at temperatures well below freezing. 1

Actual commercial tests" of the ferro alloy quettes described herein were made under varying conditions to determine the silicon recovery as" compared to the silicon recoveryfrom standard silvery iron. These tests are as follows:

EXAMPLE No. l

Cupola 72f using l'l-ounce pressure; opera- EXAMPLE No. 3

Cupola 48 blast pressure 9 ounces 2.8lbs. Si added er'toninthe ladle=.12 .127 tlon eight .hours w1th. a continuous stream of p metal from the cupola. The test covers three 5 Silvery iron charge days oper tion and on th second y ferro- 1 silicon briquettes were substituted for silvery sy .5 a 1 40 lbs. Splegel lIGD 1.23% S1 S1 iron on the basis of contamed slhcon. 3151 Return map 150% Si Regular charge 10 1,500 lbs. Total 21 05 1. 45% s1 100 8. 1 11 iron 2.55% gi yu g g-1 3. g1 150 s. etul'n scrap 1. 0 i s. 1 735 lbs. Purchased 8018 115021. s1 12501118. 81 m Charge 151135 sllvery 1575% '7.. 2L36 s} 1 0501b5 Steelcrap 014% Si 1 471b Si p 7 30;lbs. Briquettes(OFA)46.57 s1 13.95 lbs. 81 1,000 1 15 40 lbs. Spiegel iron 1.23% s1. .f .4911). 81

' a 3801bs. Return scrap 1.50% Si 5. 70 lbs. Si Bnquette charge 1,500Ibs. 'Iotal 21. 51 lbs. s1 1,40 81 100 lberi iron 2.557 s1 2.551115. 81 150 lbs. Return scrap i802; s1 240018.8 1 52% S1 745 lb's; Purchased scrap 1.70% Si. 1. 12.67 lbs. S1

5.5 lbs. Briquettes 16.5% Si 2.55 lbs. S1 20 Analysis 1,000.51bs. 20.11 lbs. 81 Test Sicharge 011 21 1 2188 1 2111% 1 0 Si 8 P M11 Per cent silicon in ladle metal Silvery 22 a. 11 1.50 84 SB111 iquettes- $8 51 1. 24 .01 108 .84 Re al- Bri uette Re ar 5 1 099 i Tune 01 test g i g Briquettes 22 3.08 1. 40 .068 090 .82

1, 10 1.81 r 1. 1; Tensile V it? i351 1:36 Test 5. 8.1. Transverse 1. 83 1.80 1.98

123 8"15 ,0 .330 EXAMPLE No. 2 44,000 2,835 .279 I, p 50,890 3,005 .391 cufpola melting 16 tons per hour made four test runs as follows: Tesjtsfih and C with silvery iron and fB and D replacing silvery iron with fe rro silicon briquettes as described above. Two types of iron were made each day 111101118 Tcharges useewere as follows:

, l in the manner described are charged into a v Pofinds .Regmar Pounds cupola, or into a bath of molten metal in a fur- WY. .mix, s1 mix, lbs. 81 lime or ladle, in either an oxidizing or reducing lbs. flame, som burning of Volatile gases will be p noted but the pitch or tar binder does not burn Bessemer-pig (Si 2.457)." 1,025 1,025 10 if er i in h 1 u i 1 Returns 12.10%) 0 .1 1,820 21; 10 910 20:40 o m tt g e bnq to d but Steel scrap (Si ().15 0,10 42 co es and contmues to 0d the brlquette toe y 1 8( 3- .3. 1.1 9.. gether protecting the readily oxidizable alloys m 2-500 1 23 2,500 54 5 u t l they are me ted, alloyed, combined 01 used r .50 as desired.

I claim: 7 H p 7 soft, 1. The method of making a. briquette for iron Silicon briquettes iron 11 00 108 Regular Pounds or steel making additions which consistsin mix- I V S1 11X, 3- S1 ing ferro-alloy fragments with a binder taken 7 55 from a group consisting of tar and pitch in- Bessemer pig (Si 2.45%)... 1,025 25.10 1,025 25.10 fzorporatmg. Small Stnps 0f.remforcm.g matelflal Returns s12.10% 1, 02 29.20 1,042 21.00 mto the mixture and forming the mixture into scrap olfizdfuui- 7g (1x15 422 r a briquette I 16011 1'1 6 8 orm 5 1 (m q 4 2. The method of making a brlquette for non P 2,500 62-41 2,500 55-63 0 or steel making additionswhich consists in' mixi ing ferro-alloy fragments with-a binder taken Analysis of heats -Test A B o '1) Sample #1 Sample #2 Sample #1 Sample #2 Sample #1 Sample #2 Sample #1 Sample #2 '..Si l i0011-,per cent 2.32 1.11 2.82 1.88 2.31 I 1.00 2.31 202 Totalcarbon... 8-60 3.33 a. 55 3.39 3.56 3.41 3.65 .55, 'Tensile, p. s. 1-

22,930 30,090 "25,050 29,110 23,380 20, 800 v11, 550 20, 850 Transverse-.- 8,. 4,300 .-a,480 4,090 3,920 4,010 2,020 4,210 Deflection (in 188 183 10 ,200 112 ;,119 Brinnel -191 163 "119' 110 131 187 from a group consisting of tar and pitch incorporating small strips of paper into the mixture, and forming the mixture into a briquette.

.3. The method of making a briquette for iron or steel making additions which consists in mixing ferro-alloy fragments with a binder taken from a group consisting of tar and pitch incorporating leather shavings into the mixture and forming the mixture into a briquette.

4. The method of making a briquette for iron or steel making additions which consists in mixing ferro-alloy fragments with a binder of hot, high melting point pitch incorporating small strips of reinforcing material into the mixture and applying suitable pressure to form the mixture into a briquette.

5. A briquette for iron or steel'making additions composed of ferro-alloy fragments and a binder taken from a group consisting of tar and pitch and small strips of reinforcing material incorporated in the briquette.

6. A briquette for iron or steel making additions composed of ferro-alloy fragments and a binder taken from a group consisting of tar and pitch and. smallstrips of paper incorporated in the briquette.

'7. A briquette for iron or steel making additions composed of ferro-alloy fragments and a binder taken from a group consisting of tar and pitch and leather shavings incorporated in the floriquette.

CALBERT L. VANCE.