Carborundum brick standard and manage change target

The carborundum that different union combines carborundum together to make different sort namely is fireproof material. Does common combinative form have: ? ?Si3N4) of  of  of rare ⒌ of Min of  of word of  of rare ⒛ of Min of technetium of  of wholesale of two Min rare ⒀ combines punish, recrystallization (R-SiC) and silicon of reaction agglomeration ooze. Carborundum pledges the property of fireproof material depends on combinative appearance.

 

① clay combines carborundum product (Clay-SiC)

 

It is prevailing carborundum simple fireproof stuff. It is combine 10%~40% clay and carborundum grain one case burden, squelch or pound dozen after shaping firing in general kiln furnace can. The Ma Fu of furnace of kiln of zincic smelting furnace, pottery and porcelain board wait for use Clay-SiC.

 

② oxide combines carborundum product (SiO2-SiC)

 

It is more actually it is combinative appearance with SiO2. It is fine pink of the SiO2 small pink 5%~10% or quartz and SiC grain collective burden, need to add flux sometimes, after suppress shapes, be in general kiln furnace firing. Its characteristic is to be in firing go up in SiC grain with wrap up of film of the SiO2 in use process, fight oxidisability greatly excel Clay-SiC, high temperature intensity is very high also. This kind of product is used extensively make fire china (> 1300 ℃ ) kiln furnace refractory slab, life raises one times above than Clay-SiC.

 

③ Mo Laishi combines carborundum product (Mullite-SiC)

 

In the burden that adds small pink of α-Al2O3 small pink and SiO2 SiC, suppress shapes, into Molaishi in the Al2O3 in agglomeration process and SiO2 union; uses a process in, the SiO2 that SiC oxidizes and becomes also forms Molaishi with Al2O3 partly. Stability of thermal shock of this kind of material is good, use extensively at making china use saggar, refractory slab.

 

④ nitrogen changes silicon to combine carborundum product (Si3N4-SiC)

 

metallic silicon pink and SiC arenaceous a burden, after shaping, in nitrogen protection falls firing, si and N2 reaction form Si3N4 to rise SiC union thereby. This kind of material is used extensively at making blast furnace be provided with carborundum brick, fireproof kiln to wait.

 

Goods of ⑤ recrystallization carborundum (R-SiC)

 

It is raw material with α-SiC, join effective exterior activator to make α-SiC makings starch through proper grain grading, pouring after shaping (also suppress shapes) agglomeration falls at the high temperature of 2000 ℃ above in Ar atmosphere or vacuum sintering furnace, siC evaporates and recrystallization is condensed to combine SiC grain thereby in SiC grain copula. Intensity of its high temperature is high, fight oxidation ability strong, thermal shock stability is good, it is stuff of good high temperature project. The kiln furnace of industry of pottery and porcelain, emery wheel uses R-SiC beam to build kiln car, can use to 1600 ℃ .

 

Goods of carborundum of silicon of ooze of ⑥ reaction agglomeration (SiSiC)

 

The suppress after mixing in proportion with α-SiC and black lead pink or vacuum are crowded piece shape, heat to be controlled to 1650 ℃ , adopt fluid posture or base substrate of infiltration of Si of gas phase general, make generate β-SiC with the reaction since black lead, rise α-SiC grain union, achieve compact change. The characteristic of this material: A. Without open pore, the O2 when using cannot infiltration arrives data is inside, have consequently extremely strong fight oxidize and fight corrode ability;b. Below high temperature fight double losing strength is R-SiC, carrying capacity rises substantially: C. Very good heat conduction ability and wear-resisting function: D. Till use temperature limit (1350 ℃ ) , its bulk stability is very good;e. As a result of the Si of infiltration 10%~20% , its are highest working temperature does not exceed 1350%~1380 ℃ , than R-SiC low;f. The 2~3 that service life is Si-SiC times. The use temperature of this kind of material can satisfy the requirement with most pottery and porcelain and firing emery wheel, oneself the pit that makes new generation provides data, have the tendency that replaces Si3N4-SiC and R-SiC kiln to provide greatly.

 

Carborundum goods definition is various, it is to use carborundum data, according to all sorts of craft, make and become. Carborundum goods can be divided it is a lot of kinds.

 

1, Si3N4-SiC brick

 

Si3N4-SiC brick is to use SiC and Si pink to be raw material, via the firing refractory products after nitrogen is changed. SiC, Si3N4 is covalent bond compound, agglomeration is very difficult. In the SiC grain of much grading and fine pink, join the industrial silicon white of mill, si and N2 undertake 2N2+3Si→Si3N4 reaction agglomeration below high temperature. The Si3N4 that generates when reaction and SiC grain are united in wedlock cheek by jowl and form the carbonization silica brick that is combinative appearance with Si3N4. Consider to discover, most Si3N+ union is acicular or fiber shape structure, all round grain of consist in SiC or the hole place of SiC grain, si3N4 shows freely stagger structure and SiC grain to be united in wedlock cheek by jowl, make have very high normal temperature and high temperature strength.

 

2, Sialon-SiC brick

When 1700 ℃ , in the square phasor that forms in Si3N4-Al4N4-Al4O6-Si3O6 place, have it is start with Si3N4 to 4/3(Al2O3, a1N) is outspread, comprise the β-Sialon photograph that changes inside quite big range, have it is start cardinal principle with Si2N2 to X photograph direction outspread, comprise the O-Sialon photograph that changes inside lesser limits. In the manufacturing process of Si3N4-SiC goods, join right amount add thing, make oxygen enters Si3N4 crystal lattice, make appearance of a certain quantity of β-Sialon solid fuse-element, can make a Sialon-SiC brick thereby

 

3, combine SiC brick oneself

Industrial silicon and carbon are joined in industrial α-SiC raw material, the reaction of Si(s)+C→SiC(s) produces below high temperature reducing atmosphere, generate β-SiC, be united in wedlock with grain of former unripe high temperature α-SiC, make out combine SiC material, make goods has good performance. Express the 3 SiC that produce for our country to pledge the SiC of refractory products and abroad pledges the manage of refractory products changes target, with abroad congener product photograph is compared, the SiC that our country produces pledges each respect index all achieved refractory products the level of foreign congener product.

 

The sort of carborundum goods and utility:

Industry of 1. nonferrous metal smelt applies

 

Use carborundum to have high temperature resistant, strength is great, heat conduction performance is good, fight concussion, make high temperature heat secondhand material, be like furnace of firm fill distill. Rectification furnace tower dish, aluminous electrobath, copper is molten furnace liner, zinc powder furnace uses arc template, thermocouple protects a canal to wait a moment.

 

Respect of 2. steely industry applies

 

Those who use carborundum is anti-corrosive, fight caustic of thermal shock wear-resisting. The characteristic with good heat conduction, used at liner of large blast furnace to improve service life. Use its coefficient of thermal conductivity, heat radiation, the character with high fever great strength, make laminose kiln provide, can reduce kiln to have a capacity not only, still improved the outfit capacity of kiln furnace and product quality, shortened production is periodic, it is glaze of pottery and porcelain carbonadoes the indirect material that burns agglomeration ideal.

     

The application of industry of 3. metallurgy mineral separation

 

Carborundum hardness is next to diamond, have stronger wear-resisting performance, it is room of wear-resisting conduit, impeller, pump, come back stream implement, the good stuff that mine fights liner, providing wear-resisting performance is cast-iron, the 5-20 of balata service life times, also be one of good stuff of aviation flight runway.

 

Architectural pottery, the application of respect of emery wheel industry uses its coefficient of thermal conductivity. Heat radiation, the character with high fever great strength, make laminose kiln provide, can reduce kiln to have a capacity not only, still improved the outfit capacity of kiln furnace and product quality, shortened production is periodic, it is glaze of pottery and porcelain carbonadoes the indirect material that burns agglomeration ideal.

Manage changes target:

 

Project	Oxide combines carborundum to turn	Corundum carbonization silica brick	Silica brick of Mo Laishi carbonization	Silicon not brick
SiC%	≥ 90	≥ 70	≥ 65	≥ 20
Al2O3%	-	-	≥ 20	≥65
Bulk density G/cm 3	≥ 2.6	≥ 2.7	≥ 2.3	≥ 2. 55
Apparent pore rate %	≤ 17	≤ 22	≤ 20	≤19
Intensity of normal temperature compression Mpa	≥ 100	≥ 100	≥ 80	≥ 80
Loading bate begins temperature ℃ ( 0.2mpa , 0.6% )	≥ 1650	≥ 1700	≥ 1600	≥ 1600
Coefficient of thermal conductivity (1000 ℃ ) , w/(m· K)	10-15	6	-	-