CA2055253A1 - Dual bond taphole mix - Google Patents

Dual bond taphole mix

Info

Publication number
CA2055253A1
CA2055253A1 CA 2055253 CA2055253A CA2055253A1 CA 2055253 A1 CA2055253 A1 CA 2055253A1 CA 2055253 CA2055253 CA 2055253 CA 2055253 A CA2055253 A CA 2055253A CA 2055253 A1 CA2055253 A1 CA 2055253A1
Authority
CA
Canada
Prior art keywords
taphole
mix
sized
mesh
calcined
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
CA 2055253
Other languages
French (fr)
Inventor
Gustave O. Hughes
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dresser Industries Inc
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of CA2055253A1 publication Critical patent/CA2055253A1/en
Abandoned legal-status Critical Current

Links

Landscapes

  • Ceramic Products (AREA)

Abstract

DUAL BOND TAPHOLE MIX

ABSTRACT OF THE INVENTION
A taphole mix which contains a dual bond system including a liquid novolak resin and a powdered pitch.
Such a mix develops a quick initial set and a slow final set. This mix has been found to be highly effective in the soaking bar practice used to seal tapholes in blast furnaces. The preferred mix contains about 72 wt.% calcined fireclay aggregate sized - 3 mesh, 10 wt.% crude kyanite, sized -100 mesh, 3 wt.%
coke breeze, sized -1/4", and plus additions of about 10.5 wt.% powdered pitch, 8.5 wt.% methylnapthalene #2 solvent, and 2 wt.% liquid novolak resin.

Description

20~2~3 DUAL i3OND TAe~QLE MIX

~ACXQR(~ OF TH E I~IY~Q~
The present inventlon relates to taphole mixes rOr use in metal-maklnq ~urnaces and particularly large production blast furnaces. Tapholes (also re~erred to s as iron notches) are notch-shaped ports located ln t~e lower hearth Or metal-~aking ~urnaces.
At the present tim- resin bondet taphole ~ixes are utilized to seal tapholes in such ~urnaces. These mixes typically contain high alumina or calcined fireclay aggrègates, optional SiC or graphite, crude clay, high carbon yielding resins, silicon powder, and a solvent for the resin such as triethylene glycol.
U.S. Patent 4,792,578 describes such materials and the advantages of the resin binder over prior art which dealt with pitch or coal tar as the binder and creosote as the solvent.
In practice, taphole mixes are placed in a device called a mud gun. This "gun" is actually an extruder which is swung up to the taphole. The extruder pushes the taphole mix into the taphole of the furnace against the air pressure within the confines of the furnace.
The "gun" is held against the taphole until the taphole mix hardens. After a given time, the taphole mix has sufficient strength so that the gun can be removed and the taphole is safely sealed. To reopen the taphole for tapping, a drill is usad. Typical tapholes are about 12 n wide with a height of about 18" and a depth of about 6'. Tapholes are plugged after each cast. A
typlcal blast furnace is tapped about 10 times per day.
Recently, many blast furnace operators have begun to use a ~o-called soaking bar practice to seal their tapholes. In the soaking bar practice, after the tapholq mix is extruded into the taphole, the mix is allowed to harden for a ~ufficient time until the gun can be removed without the mix collapsing. Then a solid metal bar i5 insarted through the semi-set taphole mix to allow heat to b~ drawn up the entire lenqth Or the taphole. ~hls procedure provldeq the temperature re~ulred to permanently set the taphols ~ix .
To begin a cast from the furnace, the soakinq bar is si~ply retracted and at tho end of the cast the taphole is again resealed to pr~vent slag and burden rrOm escaplng th- rurnac-.
Although conventional taphole miXes work reasonably well is soaking bar applications, there is a need for an improved taphole mix which sets quickly so as to support a soaking bar readlly and which is easy to work with.

] ~52~3 conventional taphole mixes ~hich utilize coal tar pitch or petroleum pitch are initially so~t but with heat set at relatively steady rates. The present invention utilizes a dual bond consisting o~ llquid novolak resin and e~ther coal tar pitch or petroleum pitch. In this system, the resin ~tarts to s~t at a faster rate than the pitch. This ensures that the taphole mix has sufficient strength so that the "gun"
can be removed from the hole in a relatively short tlme. By controlling the amount of resin in the mix, the taphole mix can have sufficient strength so that the soaking bar can be inserted through the taphole without tearing away the plugged mass. After the soaking bar i~ in the taphole, the pitch then sets and begins to carbonize. A very strong bond is thus created .
The dual bond of liquid novolak resin and either coal tar pitch or petroleum pitch also offers several unique and unexpected features. First and foremost, this dual bond system allows furnace operators to safely seal the taphole using the soaking bar practice within a predictable and acceptable time frame. Such a desirable feature was not possible with conventional mixes. S~cond, a mix containing these two binders has an extrudable consistency at a lower solvent level than a mix which only contains coal tar pitch or petroleum pitch. This lower solvent level provides for easier extrusion and also results in a lower apparent poro~ity. Less extrusion pressure is desirable in term~ of equipment life and maintenance and lower apparent porosity is highly desirable since it can reduce erosion during a cast. A mix containing the dual bond, for example, showed a 23% decrease in coked porosity and a 50% decrease in extrusion pressuxe.
Accordingly, a principal object of the present invention iB to provldo an improved taphole mix which 2~253 ls hlghly Orrectivo ln th- Joakln~ bar practlce used to seAl taphole- ln blagt rurnacos. Another and more speclrlc ob~ect or the lnventlon 19 the provislon Or a dual bond taphole mix ln which the resin starts to set at a faster rate than the pitch so that the gun can be removed in a relatively short time. Yet still another object o the present lnventlon ls to provide a taphole mix which ls easlly extruded and has a lower apparent porosity. Other objects and rurther scope Or applicability o~ the present invention wlll become apparent ~rom the detailed description to follow taken in conjunction with the accompanying drawing.

20~2~3 ~RI~EF DEsc~IpTIoN--F_THE--~BA~
Flg. 1 ig a graph lllUstratlng cold crushlng str~ngth v~rsus tl~ at SOO~F.

2~2~

qE~L~ DESCRIPTI0N OF T~ E~EE~E~ E~Q~IM~T
In Fig. 1 ~r the drawln~s, a rirst curve labelled A repre-cnts the cold crushing strength Or an exemplary ~ix of the present invention including both a pitch and novolak resin binder and a second curve la~elled 8 illustrates the cold cru~hing strength o~ a conventional ~ix containing only a pltch binder. The variation between curves A and B in tho flrst 2 hours shows that the dual bond initlally develop~ strength faster than a mix containing only a pltch binder.
In accordance with the present invention, an exemplary mix contains 65 to 95 wt.t refractory aggreqate, sized -3 mesh either individually or in combination with the following aggregates: silica, lS calcined fireclay, calcined high alumina aggregate, calcined bauxit~, andalusite, fused alumina, tabular alumina, coke breeze, silicon carbide or graphite. The mix also includes O to 20 wt.~ crude kyanite, sized -100 mesh and S to 15 wt.% crude ball clay. The mix may also contain O to 20 wt.% .erro-silicon nitride powder which is effect~ive in providing improved erosion resistance in large furnaces and 0 to 5 wt.~ powder silicon which may be effective in improving hot strength. Plus additions include 1 to 4 wt.% liquid novolaX rosin, such as RL 2304 manufactured by ~orden, Inc., 8 to 14 wt.% powdered pitch either coal tar pitch or potroleu~ pitch, and 6 to 15 wt.% solvent such as methylnapthalene #2 or #5 which is needed to dissolve th6 pitch.
A specific taphole mix of the present invention which provides the improved properties and allows operators to follow the soaking bar practice in a controlled, trouble-free manner includes:
72% calcined fireclay aggregate 10 crudo kyanite 10 ball clay 5 graphite 3 coarse carbon 20S~2~
) Plus addltions 2~ liquld novolak resln 10.5 ~ine coal tar pitch 8.5 solvent While the inventlon has been described in connection with a prer-rred embotiment, it 1~ not intendHd to limit the JCOp- O~ th- inv-ntlon to the particular ~orm set ~orth, but, on the contrary, lt is intended to cover such alternatlves, modi~icatlons, and equivalents as may be included within the spirit and scope o~ the invention a~ derlned by the appended claim~.

Claims (7)

1. In a taphole mix, the improvement comprising a dual bond system including a liquid novolak resin and a powdered pitch.
2. The improved taphole mix according to claim 1 consisting essentially of 65 to 95 wt.%
refractory aggregate sized -3 mesh, 0 to 20 wt.% crude kyanite, sized -100 mesh, 5 to 15 wt.% crude ball clay, and plus additions of 1 to 4 wt.% liquid novolak resin, 8 to 14 wt.% powdered pitch, and 6 to 15 wt.%
methylnapthalene solvent.
3. The improved taphole mix according to claim 2 wherein the refractory aggregate is selected from the group comprising silica, calcined fireclay, calcined high alumina aggregate, calcined bauxite, andalusite, fused alumina, tabular alumina, coke breeze, silicon carbide, graphite and combinations thereof.
4. In a soaking bar method of sealing a taphole in a metal-making furnace, the improvement comprising applying an improved dual bond taphole mix including both a liquid novolak resin and a powdered pitch.
5. The method of claim 4, wherein said improved taphole mix comprises 65 to 95 wt.% refractory aggregate sized -3 mesh, 0 to 20 wt.% crude kyanite, sized -100 mesh, 5 to 15 wt.% crude ball clay, and plus additions of 1 to 4 wt.% liquid novolak resin, 8 to 14 wt.% powdered pitch, and 6 to 15 wt.% methylnapthalene solvent.
6. The method of claim 5, wherein the refractory aggregate is selected from the group comprising silica, calcined fireclay, calcined high alumina aggregate, calcined bauxite andalusite, fused alumina, tabular alumina, coke breeze, silicon carbide, graphite and combinations thereof.
7. The method or claim 4, wherein said furnace is a blast furnace.
CA 2055253 1991-02-20 1991-11-12 Dual bond taphole mix Abandoned CA2055253A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US65816991A 1991-02-20 1991-02-20
US658,169 1991-02-21

Publications (1)

Publication Number Publication Date
CA2055253A1 true CA2055253A1 (en) 1992-08-22

Family

ID=24640186

Family Applications (1)

Application Number Title Priority Date Filing Date
CA 2055253 Abandoned CA2055253A1 (en) 1991-02-20 1991-11-12 Dual bond taphole mix

Country Status (2)

Country Link
CA (1) CA2055253A1 (en)
MX (1) MX9200718A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7485186B2 (en) * 2002-06-17 2009-02-03 American Clay Enterprises, Llc Clay plaster
CN110642631A (en) * 2019-10-11 2020-01-03 鄂尔多斯市瀚博科技有限公司 Ramming material for ladle lining and preparation method thereof

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7485186B2 (en) * 2002-06-17 2009-02-03 American Clay Enterprises, Llc Clay plaster
US7789960B2 (en) 2002-06-17 2010-09-07 Armin Croft Elsaesser Clay plaster
US8007586B2 (en) 2002-06-17 2011-08-30 Armin Croft Elsaesser Clay plaster
CN110642631A (en) * 2019-10-11 2020-01-03 鄂尔多斯市瀚博科技有限公司 Ramming material for ladle lining and preparation method thereof
CN110642631B (en) * 2019-10-11 2022-03-01 鄂尔多斯市瀚博科技有限公司 Ramming material for ladle lining and preparation method thereof

Also Published As

Publication number Publication date
MX9200718A (en) 1992-08-01

Similar Documents

Publication Publication Date Title
JP5324830B2 (en) Blast furnace outlet closure material
US5866490A (en) Monolithic refractory and gunning material using the refractory
KR900003315B1 (en) Repair-material of brick
EP1420003B1 (en) Repair refractory composition
EP0434421B1 (en) Protective layer for linings in metallurgical furnaces and the like
CA2055253A1 (en) Dual bond taphole mix
JP3020625B2 (en) Mud material for blast furnace taphole
US4468780A (en) Method of lining a steel-making furnace
US4436678A (en) Method for hot repairing the inside of a furnace
KR100891860B1 (en) Taphole mix of blast furnace having high corrosion resistivity and superior adhesive property
KR960015652B1 (en) Composition of mud
JP4510229B2 (en) Blast furnace outlet mud material
JP2992211B2 (en) Taphole blocking material
JP2002160981A (en) Stopper for pig iron tap hole of blast furnace
CN117800715A (en) Micro-expansion high-strength wear-resistant zirconium-inlaid fire clay and preparation method thereof
JPH08231278A (en) Material for closing tap hole
JPS61146772A (en) Spray mending method
JPH06263523A (en) Production of carbon-containing unburned brick
JP2610280B2 (en) Mud material for blast furnace taphole
JPS60103105A (en) Method for plugging tap hole of blast furnace
JPH06345551A (en) Refractory for casting molding
JP3223039B2 (en) High durability baking repair material
JPH11349383A (en) Closing material for molten pig iron tapping port
JPS5912620B2 (en) Blast furnace tap hole blocking material
JPS5827232B2 (en) Monolithic refractories with excellent corrosion resistance

Legal Events

Date Code Title Description
EEER Examination request
FZDE Dead