The molten iron in blast furnace, come out to shed the passageway of classics from taphole, it is trough namely, divide again among them advocate channel, broken bits channel and iron channel, advocate the function of channel is depart molten iron and broken bits, advocate the broken bits in channel from cast aside broken bits implement lintel coping enters taphole channel, namely broken bits channel, molten iron from cast aside broken bits implement passageway of lintel bottom molten iron, namely iron channeling passes, iron of implementation broken bits is detached. The fireproof material of the laid in channel, call iron channel makings normally. Namely channel of blast furnace taphole makes line and the fireproof data that when repairing, use. Get in taphole channel use process of molten iron erode, drossy chemistry is eroded, the influence such as the thermal shock stress that wave motion of airy oxidation, temperature produces. Advocate channel is important, molten iron velocity of flow fast, temperature is high, bear the joint action of broken bits iron, broken bits channel and iron channel had shed broken bits and iron respectively, velocity of flow is slower, discharge is lesser, temperature is inferior also, of fireproof to channel line material erode slower also.
As blast furnace large change and aggrandizement smelt, discharge of broken bits iron increases temperature of the iron that reach broken bits to rise, the use condition that taphole channel uses fireproof data is more and more abominable. According to statistic, in be being used up to the unit of fireproof material in molten iron, taphole field (iron channel makings and mud of prepare Chinese medicine by roasting it in a panbig gun) occupy about 71% , taphole channel is built during battle of furnace of blast furnace generation and upkeep costs and price of mud of prepare Chinese medicine by roasting it in a panbig gun always close, expenditure of more accessory than repairing a blast furnace newly to reach its equipment is tall still. For this, each unit uses the material of fireproof material to reach the design of function, structure, method that build line to wait character to taphole channel, have the research of extensive development. More and more use pouring expect or pound dozen of makings, large blast furnace has 2 commonly, 3 taphole, basically use pouring makings, small blast furnace is odd iron mouth commonly in, use pound dozen of makings or wash-and-wear and pouring makings, because fireproof material technology progresses, some small blast furnace also are used now pouring makings. But no matter be pouring,pound dozen of makings, the iron channel material that blast furnace uses basically is Al2O3, SiC, form of C qualitative adventitious is fireproof material, belong to low cement namely or exceed low cement pouring makings, and pound dozen of makings and repair makings.
One, channel of blast furnace taphole uses Al2O3, SiC, C is qualitative pouring makings:
From 20 centuries 70 time begin to develop Al2O3, SiC, C is qualitative pouring makings, as indeterminate form fireproof material technology progresses, developed clay union of union, aluminous acerbity calcic cement, silicon collosol union, ρ - 2 hydrogen of Al2O3 union, phosphoric acid are aluminous the Al2O3 such as union, SiC, C is qualitative pouring makings. The skill that adds construction and maintenance to wait progresses, developed again avoid roast and pouring makings, wash-and-wear model pouring makings, do as one pleases pouring makings, environmental protection pouring makings. But it is to belong to Al2O3 from beginning to end, SiC, C is qualitative pouring makings. Representative burden sees a table 1.
The representative burden that expresses makings of 1 iron channel (W) %
In pouring mix into of the beard in makings accelerates dry agent or explosion proof agent, basically fiber of aluminium of aluminium powder, lactic acid, polystyrene and dimension of carbolic drill steel wait, in order to suit fast and roast.
Taphole channel is pouring makings have high quality, medium character and low tasted cent. High quality main by electric frit compact corundum, board shape corundum is made up, for large and medium-sized blast furnace is used. The corundum that use palm is blocked to make up in, in offerring, small blast furnace is used. Low block article make up with tall aluminous aluminous grog.
In recent years, around Al2O3, SiC, channel of C department iron is pouring makings have a lot of research, the iron channel that the compact corundum that replaces electric frit method with the board shape corundum that agglomeration law produces makes up is pouring makings, in taphole advocate position of line of channel broken bits is used, flake to original craze the phenomenon has clear improvement, have good anti-impact properties, eliminated pouring inside makings job line pull stress, solved pouring the craze problem of makings. With frit of report of natural raw material inferior Bai Gangyu is replaced with industrial alumina of the compact corundum of electric frit super- channel of low cement iron is pouring expect in large blast furnace trough is used, obtain same use result, managing cost. To reduce pouring the manufacturing cost of makings, somebody uses makings of leveling of special type aluminous alumina to replace palm corundum to make aggregate, in matrix same situation falls, expect with the iron channel of palm corundum aggregate performance is comparative, its are fought erode summary difference, it is better that impervious appears a gender, have better integral performance, can replace palm corundum partly. Return some research to use aluminous chromic broken bits to replace Al2O3 of palm corundum preparation, SiC, C iron channel is pouring makings, the result is: Replace 0-34% of palm corundum aggregate when aluminous chromic broken bits when, pouring the normal temperature of makings, high temperature capability is good, when when 200 eye fine pink is replaced by aluminous chromic broken bits, bulk density, high temperature is fought fold the function such as intensity to rise, and appreciably raises the aggressivity that fight broken bits. Iron channel makings introduces aluminous chromic broken bits to reduce cost not only, managing still resource, reduced environmental pollution. Return some to use the pyrophyllite with inferior value, rutile and coke complex Sialon, body of pink of TiNC answer photograph replaces traditional Al2O3, SiC, C is qualitative pouring the corundum of the of 30% high cost in makings, carborundum, alumina is small pink, the intensity after heat treatment rises, advocate channel connects iron makings to amount to 15, 170 thousand T, cover 2 times when irrigating, because degenerative layer is thinner, can save Al2O3, SiC, C is pouring makings dosage.
To raise the heatproof shake sex that iron channel expects, somebody introduces the andalusite of distinct size, reduce as andalusite granuality, apparent pore rate is reduced gradually, after bulk density is reduced first, turn big, heatproof shake sex rises.
Fight oxidisability to rise, early or late somebody considers to add NiO or ZrB2 or nitrogen change ferrosilicon to wait, among them nitrogen changes ferrosilicon to be in atmosphere of high temperature oxidation, pouring the Si3N4 in the oxidation ferrosilicon of makings surface oxidizes above all generate SiO2, make the principal part of oxidation layer, as the oxidation that Tie Xiangcai expects, form ferric oxide, dropped the melting point of oxidation layer, and reduced fuse-element viscosity, form enclothe the oxidation layer at material surface, and prevent carbolic element combustion. Because nitrogen changes ferrosilicon to add a capacity little, the iron of material interior is with ferric oxide the form exists, not big to influence of performance characteristics of material high temperature. Taphole channel distributes the line that it is broken bits and iron line, broken bits line asks to have the better sex that fight broken bits, and iron line requirement has to ferric oxide taller fight erode ability.
Line of iron of prep above of content of SiC of broken bits line, because SiC can rise,fight broken bits ability. SiC content problem causes wide attention, a few more Euramerican national Al2O3, SiC, C is qualitative pouring makings contain SiC 20% left and right sides, of Japan pouring content of the SiC in makings 70% the left and right sides, a few research of our country think SiC content 35% advisable. Add SiC content further, fluidity becomes poor, bulk density drops, remains expands the quantity increases, the sex that fight broken bits becomes poor. Because this raises SiC content to must choose good dispersive dose, adjust good grain composition, in order to improve construction performance. MgO content should add in iron line, with counteractive FeO erode, because pointed spar fights FeO,erode ability stronger. Iron fluid and broken bits interface, should use give attention to two or morethings to fight the fireproof stuff that broken bits and iron eat, namely the corundum of content of tall SiC, taller black lead, carborundum, charcoal is qualitative pouring makings. In broken bits and line of airy have a common boundary, be oxidized strongly by airy, want to choose to fight broken bits and the fireproof material that fight oxidation to wait.
The look of iron channel makings that combines with cement is compared, ρ - what Al2O3 is united in wedlock is pouring makings have higher intensity and the better sex that fight broken bits. As a result of ρ - Al2O3 has strong hydrolysis character, hydrolysis is too fast, make pouring makings liquidity is lost inside short time, cause pouring makings cannot normal construction. The dispersive dose with accordingly right choice and join delay to coagulate agent boric acid or use delay to coagulate model ρ - Al2O3 appears very important. Dispersive agent sort has get together carboxylic acid salt, 6 slant phosphoric acid natrium + condensate of naphthalene sulphonate formaldehyde, polypropylene acerbity natrium, 3 get together condensate of cyanogen amine formaldehyde. Get together among them carboxylic acid salt is better, but the price is high, it is next 6 slant phosphoric acid natrium + the value of going from place to place of condensate of naphthalene sulphonate formaldehyde is great. And join boric acid to be able to make ρ - Al2O3 union is pouring makings there still is good liquidity after 90min, can contented construction asks.
ρ - Al2O3 union is pouring makings, its collect makings can use natural raw material, also can use synthetic raw material, applicable to acerbity, alkaline or neuter raw material. As low as existence of union of silica raw material in all melting point (1595 ℃ ) , if be used below not high temperature, but what preparation has high strenth, bulk to stabilize is pouring makings. With basic raw material, if the reaction such as magnesia generates pointed spar, rise pouring the function of makings. And it is better to cooperate the effect with neuter and fireproof raw material.
The Al2O3 that large blast furnace uses, SiC, C is qualitative pouring pair of its function such as the carbolic source that stuff place uses, bond, accretion and environmental protection have bigger effect. At present Al2O3, SiC, channel of C qualitative iron is pouring expecting use carbolic cause is common is bulbiform bitumen or coke, join a quantity to be normally 1, 3wt% , however bulbiform bitumen contains benzene and Bi constituent, the Huang Yan of carcinogen arises when high temperature is used. Coke is contained sulfur and volatilize cent, healthy to human body generation is minatory.
For this, pouring to channel of swage of macrobian, environmental protection the development of makings, cause the attention of people, it is to carbon the source has thorough and careful research above all. If somebody is used,join the carbon black that build bead, because build a carbon black to contain carbon the volume is high (＞ 98% ) , the area that compare a list is small (＜ 12m2/g) , do not pollute an environment, make pouring material composition is compact, hot condition strength is great, the aggressivity that fight broken bits is admirable. Return somebody to join CarboresP of pink of a kind of colophony that contain carbon in iron channel makings, its benzene and Bi content has 0.03% only (W) the left and right sides, and incomplete carbon quantity is as high as 85% (W) above, and use silicon dissolve cementation close, not only do not pollute an environment, and still have construction time short, heatproof shake sex is good, chemical stability is strong, it is better to fight oxidisability wait for an advantage. Its reason depends on in below low temperature, silicon collosol dehydrate is formed, Si, O, Si, gel network structure, intensity of the low temperature in assuring, mo Laishi of many fiber shape is generated below high temperature, for pouring makings provided higher normal temperature and high temperature strength. And be in add fiber of organic explosion proof, foaming agent AC, silicon collosol union is not affected pouring of makings fight cruel crack function, and ρ , what Al2O3 is united in wedlock is pouring makings go against fight cruel crack function, it is the significant step that increases strength.
Return somebody to replace carbon through adding Si3N4 of substance of Sialon precursory form, the performance that excogitates Sialon union is good, the do as one pleases with friendly environment is pouring makings. In burden, should join Al2O3 small white 13% , silicon small pink 4% , aluminium acid calcic cement 3% , Si3N4 6% , carbonization is boracic 0, 4% , 6 slant phosphoric acid natrium is the agent that decrease water, the do as one pleases that can obtain flow to be worth 185mm to control is pouring makings. Because Si3N4 and broken bits iron are not easy,joining Si3N4 is embellish is wet, make material fights broken bits sex to increase, sialon is generated to be oxidized not easily in use process, changed material matrix to combine a form, the firm that elevated matrix, direct union leads solid photograph, rose to fight broken bits sex. After joining carbonization boron, in warm up oxidation of melt into of the oxygen in the process is boracic, in in lukewarm next melt are fluid photograph, stimulative material agglomeration, make its intensity increases. Photograph of formation the glass that contain boron, compact oxidation film is formed in material surface, reduced the farther oxidation of material, achieve the goal that fights oxidation. Return some to use carbon black N990 to regard carbon as the source, also somebody uses HY of new-style carbon source, 1, it is the carbolic particle through building bead namely, have low-down sulfur content, belong to an environment friendly profile makings, the iron channel that makes up for carbolic source with it is pouring makings, use in spot of blast furnace of some ironworks 2580m3, not fumy, fight the oxidation, sex that fight broken bits first-rate.
2, in small blast furnace uses Al2O3, SiC, C pounds dozen of makings to reach character wash-and-wear and pouring makings
2.1, pound dozen of makings:
As a result of in small blast furnace is individual taphole commonly, taphole time interval is short, cannot assure general and pouring the conserve that makings construction place needs, roast time, so taphole channel is to use commonly not roast and direct use pound dozen of makings, of the combinative system that uses a kind not to produce vapour in use process namely pound dozen of makings, after achieving construction thereby need not roast can the purpose of direct taphole.
Channel of taphole of small blast furnace pounds the bases of dozen of makings to be in: W(Al2O3)=15%---69% , w(SiC+C)=10%---25% ;
The bases that broken bits channel expects is: W(Al2O3)=35%---45% , w(SiC+c)=15%---30% .
Ask matter content of tall aluminous aluminous grog is low, agglomeration is good (bibulous rate ＜ 4.5% ) . Grain group becomes: 8, 2mm40%---60% , 2---0.074mm30%---40% , black carborundum is less than 100 eye, carbon material can use black lead or metallurgy is anxious.
The exercise sex that pounds dozen of makings to rise and the agglomeration function in using, can add soft qualitative clay or Peng embellish land. With tar (or anthracene is oily) + bitumen makes bond, need not add water, pound after hitting need not roast can connect molten iron directly. But the flue gas in using is bigger, can pollute an environment. Make bond with colophony of liquid state phenolic aldehyde also need not roast, can connect molten iron directly, also be to avoid roast pound dozen of makings, lighter to environmental pollution. Somebody studies carborundum and phenolic aldehyde colophony add a capacity to Al2O3, SiC, the influence that C pounds dozen of makings function character, think when W(SiC)15% , pound dozen of makings intensity tall, bulk density is bigger, join a quantity to increase as SiC, pound dozen of makings to fight thermal shock sex to rise, wearability increases, but when W(SiC) exceeds 15% , wearability is reduced. When phenolic aldehyde colophony 5% (W) when, pound dozen of makings intensity taller, exceed 5% , the function that pounds dozen of makings is reduced, wearability also is reduced, when exceeding 6% , fight thermal shock sex to be reduced apparently. Still what phenolic aldehyde colophony is united in wedlock pound dozen of makings storage life short, the proposal is the spot is allocated use directly. Oxidize to prevent carbon to expect, mix metallic Al pink, Si pink and size normally, make carborundum, carbon material and aluminous aluminous grog mix together well, add silica fine pink to make shrinkproof lotion.
Collosol of useful also silicon does the iron channel of bond to pound dozen of makings, its are main raw material is especially medium corundum of aluminous aluminous grog, palm, carborundum and bulbiform bitumen, metallic silicon pink and carbonization boron burn an agent for antioxidant and hurried, add SiO2 and α at the same time - Al2O3 exceeds small pink and clay and explosion proof fiber. Join 2% (W) silicon small pink, 3% (W) clay or 0, fiber of 05% organic explosion proof combines Al2O3 to silicon collosol, SiC, the bulk density impact that C pounds dozen of makings character is not big, but to its intensity has certain effect; Contain 6% (W) α , Al2O3 small pink, 3% (W) clay has very high strength, it is good to and fight erode ability. Added fiber of organic explosion proof to rise to pound the intensity after dozen of makings is roast, and the sex that fight broken bits is reduced somewhat. Silicon collosol combines Al2O3, SiC, C pounds dozen of makings, all show after 1450C to calcine certain quality increases, be helpful for bulk stability and the sex that fight broken bits. But pound dozen of makings service life is too brief, especially dropping grog dot, general 3, 7 days are about to repair. Because pound dozen of taphole channel liner,be bottom surface only commonly compare relatively close-grained, and channel is reached to help place under exterior layer very loose, do not be able to bear or endure erode. And what pledge to same capable person is pouring makings, bulk density is higher, each place is evener, more be able to bear or endure erode, service life is longer, construction maintenance is convenient, and taphole field environment is neat. But small blast furnace is used,pound dozen of makings, it is foul atomsphere, extremely confused before general furnace.
Should use environmental protection model avoid roast pound dozen of makings, if somebody uses the resin that contain carbon + vegetable oil + colophony of aldehyde of close amine Niao + carbolic pink does Al2O3, SiC, the bond that C pounds dozen of makings character, this kind pounds dozen of makings not only avoid roast, and harmful material content is little, harmless to human body, without soot, small to environmental influence. If use pouring makings, must be wash-and-wear and pouring makings, namely pouring hind 1h can drawing of patterns, and but instantly conflagration is roast 1, molten iron is passed on 2h wheeler.
2.2, wash-and-wear and pouring makings:
In recent years, the iron channel of taphole of mouth of odd iron of small blast furnace in be aimed at is pouring makings had a large number of research. If Heibei combines an university to use all sorts of pink of jade of Baigang of palm corundum, carborundum, 325 eye, bulbiform bitumen, silicon give priority to want raw material, AC vesicant is explosion proof agent, it is bond with ash of Secar71 cement, silicon and silicon collosol respectively. Consider to reach: Join AC vesicant to be able to be reduced pouring makings dehydrate temperature, and dehydration temperature range is very wide, rose pouring of makings fight cruel crack a gender. Its principle is: In cement bond, AC vesicant and cement and water reaction make gas, tiny open pore is formed when aeriform transgression, advantageous water divides eduction, rise fight cruel crack a gender; White of electric frit magnesia is joined in system of silicon ash union, form M, S, H gel, not only increased strength, and heating in the process slow dehydrate, be helpful for pouring of makings fast and roast, rise fight cruel crack a gender; Silicon collosol union is pouring makings dehydration is controlled in 100C, dehydration is gently, advantageous and pouring of makings fight cruel crack a gender. Join 0.05% 3 get together phosphoric acid natrium (STP) make the lotion that decrease water, pouring the fluidity of makings and fight cruel it is good to crack a gender. Silicon collosol union is pouring strength of the low temperature in makings is better, high temperature generates Molaishi, increase strength further, but volume expansion ratio is older, the aggressivity that fight broken bits is poorer.
Trough of Chu Tie type uses small noodles or vermicelli made from bean or sweet potato starch of close corundum of as a result, palm corundum, carborundum, silicon, alumina small pink is main raw material, add agent of compound explosion proof, what acerbity calcic cement combines pure phosphor aluminium is fast roast and pouring makings. Do not have on 580m3 blast furnace repair use 3 months continuously, connect iron to measure above of 180 thousand T.
3, channel of blast furnace taphole repairs makings:
Taphole channel is local attaint undertakes repairing is to lengthen taphole channel the important by way of of service life. And can reduce fireproof material dosage, reduce manufacturing cost, the pollution that reduces litter to discharge pair of environments.
3.1, gush filling makings:
The condition of local and fast heat that basically solves channel of iron of large blast furnace to use a process is repaired, temperature is 100, 1450 ℃ , the Al2O3 that somebody studies to with phosphoric acid 2 hydrogen aluminium is united in wedlock, SiC, filling makings of C qualitative gush has good performance. Magnesia is blocked to be solidify agent in choosing at the same time (1, 2% ) , with phosphoric acid 2 hydrogen aluminium is in spray gun mouth is ejective mixture gush arrives repair a face to go up not to flow drip, but fast solidify agglomeration. When ply of gush filling layer 180, 250mm, gush is over 10min can taphole, use 12d continuously, gross crossing iron 48 thousand T, gush filling layer still has a few incomplete line. The congener spray that is united in wedlock with cement commonly expects use 5d is controlled, cross iron to measure left and right sides of 20 thousand T. Hot gush fills have wet with half dry method two kinds.
3.2, high temperature do as one pleases repairs makings:
Use the Al2O3 that pledges with material with makings of channel of iron of large blast furnace, SiC, C pledges do as one pleases is repaired makings, bitumen and colophony are compound bond. Because the reasonable collocation of compound bond reachs the use of suspension agent, makings of do as one pleases has good high temperature liquidity, construction is convenient. Swing iron of frit of classics drifting the mouth, slaggy erode with erode, form perforative sex break, cause whole swing liner drifting the mouth is fireproof material discards as useless, after using makings of do as one pleases to repair, service life rises 10, 20% , advocate the join place of channel, iron channel, broken bits channel is easy generation crackle, local frit damage is big by channel, use makings of do as one pleases to repair, improved service life.
3.3, do as one pleases is pouring makings:
Taphole channel, especially advocate channel front is eroded more serious, mar faster, divide outside using local gush to fill, usable also do as one pleases is pouring makings repair. Because mould and leftover iron channel expect an aperture is lesser, appearance is not neat, the do as one pleases with use liquidity better is pouring makings undertake repairing, can very good settlement problem. Do as one pleases is pouring expecting is support itself is self-prossessed difference produces take its natural course and achieve the result with gas, gentle and close-grained booth with potential energy. Do as one pleases is pouring the raw material that stuff place uses and material of original iron channel are basic and same, but should notice grain grading, with thick: In: Fine grained is 20: 45: 35, its exceed fine pink and fine pink than be 0.35, 0.5 when liquidity is good. And be achieved even (1) high temperature intensity is high, be able to bear or endure erode, fight erode, it is good to fight stability of oxidation, thermal shock; (2) fast and roast not scamper is cracked; (3) as firm as remaining liner union, do not stick broken bits iron. Unit of some scientific research do as one pleases pouring expect in iron of 2000m3 blast furnace channel damages serious place is used, after raising good pattern, with do as one pleases pouring makings undertake repairing, the quantity that connect iron amounts to above of 100 thousand T.
3.4, set irrigate:
Alleged set irrigate, it is in trough attaint arrives after certain level namely, cleared iron sheet is residual, withhold remaining liner, raise upper mould to provide next irrigate the new liner that goes up to pledge with material with incomplete line. Reduced fireproof material to use up not only so, cover repeatedly irrigate go down to be able to accomplish remaining fireproof material 0 discharge, achieve the goal that protects an environment. Our country great majority uses cold law to cover irrigate, because pare iron sheet is residual, drop temperature at the same time, so can cold set irrigate. Special those who put forward is Bao Gang channel of taphole of blast furnace of stainless steel 2500m3 uses heat to cover irrigate, the basis is investigated is concussion intermediate zone of line of area broken bits, iron and above frit damage are more serious, and advocate line of channel broken bits, iron use respectively those who differ is pouring makings, broken bits line pouring makings SiC content is high, iron line SiC content is inferior. If cover,irrigate use two kinds pouring makings, bring to construction process complex, and face of have a common boundary produces crackle easily. For this, treasure steel development goes content of a kind of SiC 18% (W) Al2O3, SiC, C is qualitative pouring makings, in line of broken bits, iron frit caustic agrees basically, rate of average frit caustic is 24mm/ iron of 10 thousand T, cover through successive heat the quantity that connect iron is repaired to be able to amount to 390 thousand T in be being irrigated.
Above repairs a method a few kinds, OK and flexible for emergency use is used, can use a kind of method, OK also a few kinds of methods are used jointly,
4, last word
Iron channel makings is the main component that blast furnace uses fireproof data, uses raw material is artificial complex blocks material high mostly, the price is high. Have 2, the large blast furnace of 3 taphole basically uses Al2O3, SiC, C is qualitative fireproof and pouring makings; What have a taphole only is medium small blast furnace basically uses Al2O3, SiC, what C pounds dozen of makings character or avoid roast explosion proof to crack is wash-and-wear and pouring makings. According to use condition, the iron channel makings of two kinds of types must be had fight molten iron to erode, fight slag to erode, the good point with fight the function such as oxidation heatproof shake stability, good.
To prolong the service life that iron channel expects, reduce fireproof material to use up, what expect to iron channel at any time want to mar a part to undertake repairing in use process, the basis mars a circumstance, the adoption of flexible for emergency use gush fills, or set irrigate, or do as one pleases is pouring, or a few kinds of methods undertake jointly at the same time, achieve a requirement.
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