The name of the invention: coke oven for precast block refractory
Technical field
[0001]
　The present invention relates to a precast block refractory suitably used in coke ovens.
Background technique
[0002]
　Conventionally, in a coke oven, silica brick have been used are lined. However, the use of silica brick, it is necessary to applying a number of bricks, there is a problem that it takes time to construction. In recent years, especially in hot repair construction, construction is often performed using a precast block refractory easy silica quality is large compared to the silica brick.
[0003]
　Such precast block refractory is required to have the hot properties of the structure. Especially in the coke oven, in addition to hot strength, under a load expansion behavior and the load under shrinkage at high temperatures (hereinafter collectively referred to as the load under inflation and deflation behavior) stabilization is sought. If the load under deflated behavior at high temperature is not stable (if deformation due to the load under expansion or under load shrinkage at high temperature is large), the hindered the resistance is increased operation when extruding the coke, precast there is a possibility that block refractory itself is damaged.
[0004]
　In Patent Document 1, a fused quartz as a main raw material, a technique of using Portland cement as a binding agent. However, large amount of Portland cement as a binder to the coke oven for precast block refractories (e.g., the main raw material 2-10% by weight) when used in, the hydration reaction of Portland cement, under load at high temperature there is a problem that the large contraction.
[0005]
　In Patent Document 2, as a binding agent (curing agent), in place of the alumina cement, which is generally used conventionally to use a colloidal silica and sodium silicate, it is trying to suppress the load under shrinkage at high temperatures . However, when using colloidal silica and sodium silicate, hot strength is lowered.
CITATION
Patent Document
[0006]
Patent Document 1: JP 56-78476 Patent Publication
Patent Document 2: JP 2013-189322 JP
Summary of the Invention
Problems that the Invention is to Solve
[0007]
　An object of the present invention is to provide, together with a high hot strength is to load under deflated behavior at high temperatures to provide a stable coke ovens for precast block refractories.
Means for Solving the Problems
[0008]
　The present inventors have conducted extensive studies in order to solve the above problems. For example, as described in Patent Document 1, if the cement was heavily used as a binding agent, under load shrinkage at high temperatures by hydration reaction with cement was not stabilized. In the case of using colloidal silica and sodium silicate as a binder, hot strength is lowered. Accordingly, the present inventors have found that in the coke oven for precast block refractory siliceous, or using a large amount of cement as a binder, instead of or with the colloidal silica and sodium silicate as binder, as a binder component P 2 O 5 by applying the components, while maintaining a high hot strength, knowledge was obtained that can be stably controlled under load deflating behavior at high temperatures.
[0009]
　That is, coke oven for precast block refractory of the present invention, the coke oven for precast block refractory siliceous, P 2 O 5 which is characterized by containing components 2 mass% 0.3 mass% or more of it is.
Effect of the invention
[0010]
　According to the present invention, exhibits high hot strength, expansion and contraction behavior under load is stable coke oven for precast block refractory at high temperatures is obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011]
FIG. 1 is a graph showing a load under deflated behavior of Examples and Comparative Examples.
DESCRIPTION OF THE INVENTION
[0012]
　Coke oven for precast block refractory of the present invention, siliceous, i.e. SiO 2 is a coke oven for precast block refractory mainly containing component. Specific SiO 2 content of components are in the range of common technical knowledge, preferably 99 wt% or more 65 wt% or less, more preferably at least 80 wt% 99 wt% or less.
[0013]
　SiO 2 as component sources, fused silica, silica (calcined silica, raw silica, etc.), etc. fumed silica, various siliceous material can be used, in the present invention, the raw material formulation, the amount of fused silica 65 mass% or more, more preferably not less than 72 mass%. The amount of silica is 17 wt% or less, the amount of fumed silica is preferably not less than 15% by mass to 0.5% by mass. That is, from the point that can counteract contraction due to dehydration during drying, the amount of fused silica at 65% by mass or more, the amount of silica is preferably either not more than 17 wt%. In this case, the amount of silica may be 0 mass%. From the viewpoint of maintaining the high hot strength, the amount of fumed silica is preferably at 15 wt% or less than 0.5 wt%. Further, the particle size of the siliceous material is preferably used in combination from the aggregate top size 5mm in consideration of packing and workability to submicron particles. Furthermore, the thermal expansion and shrinkage under a load (hereinafter referred to as "under load deflating rate".) In order to more stably, it is preferable that the above coarse particles 1mm and 25% by weight or more.
　As the raw material other than the siliceous material may be used in combination with alumina raw material as the main aggregate. The alumina material can be used fused alumina, sintered alumina. However, SiO 2 when the component is less than 65 wt%, the addition of a large amount of alumina material for hot strength is lowered undesirably.
[0014]
　P In coke ovens for precast block refractory of the present invention 2 O 5 component is functions as a binder component as described above, its content is 2 mass% or less than 0.3 wt%. P 2 O 5 content of the component is less than 0.3 wt% does not exhibit a pound functions as a binder component. P 2 O 5 when the content of component exceeds 2 mass%, the low-melting material (SiO 2 -P 2 O 5 system) that is produced in excess, is deformed due to contraction under load at high temperature increases .
[0015]
　P 2 O 5 As the component source can be used phosphates, in this case, Na are contained as impurities in the phosphate 2 O component and the K 2 from O components that suppress the formation of low-melting material, precast block it is preferably in total at most 0.5 wt% as the content of the refractory in.
[0016]
　Also, maintaining the raw material blend of the coke oven for precast block refractory of the present invention, the amount of curing accelerator is preferably at least 0.05 wt% from the viewpoint of increasing the strength at the time of curing, and a high hot strength it is preferred from the viewpoint of at most 1.9 mass%. As the curing accelerator, magnesia fine powder, slaked lime, and the like.
[0017]
　Additionally, coke ovens for precast block refractory of the present invention preferably contains no cement. If it contains cement, but under load contraction caused by hydration reaction of cement, if cement-free, it is possible to suppress the load under contraction.
[0018]
　Coke oven for precast block refractory of the present invention, the main raw material as the aforementioned silica raw material (SiO 2 sodium phosphate (P as component source) and binder 2 O 5 component source) were blended, and if necessary , organic fibers as other additives, dispersants, accelerators, retarders, blended sintering aid or the like, the construction water qs (e.g. 5% to 7% by weight) in the obtained raw material formulation in terms of the addition, the kneading, molding, curing, demolding, that drying can be obtained by the manufacturing method of the conventional precast block refractory.
Example
[0019]
　The respective raw materials were blended according to the material formulation shown in Table 1, after the addition of 6.5 wt% of the construction water, kneaded, molded, cured, demolded, specimens of the coke oven for precast block refractories obtained by drying with the expansion and contraction behavior and hot bending strength under load was measured, were comprehensive evaluation. In addition, it was analyzed chemical components of the obtained test piece. Here, fused silica, calcined silica, the raw silica and fused alumina of particle size and each less than 5-1mm and 1 mm 6: was a mixture in a ratio of 4. Further, the particle size of the fumed silica was used as an average particle diameter of 0.5 [mu] m. Incidentally, each chemical component of the raw materials, fused silica SiO 2 99.7 wt% of the component, firing silica is SiO 2 component 99.5 wt%, raw silica is SiO 2 99.7% by weight of component, fumed silica SiO 2 96 wt% of the component, Na 2 O ingredient 0.2 wt%, fused alumina is Al 2 O 3 of 100 weight%, phosphoric acid soda P 2 O 5 65 wt% of the component, Na 2 the O component 23 wt%, sodium silicate of SiO 2 64% by weight of component, Na 2 O component 22 mass%, colloidal silica SiO 2 the components 40 wt%, Portland cement SiO 2 24 wt% of the component, magnesia fines 100 mass% of MgO component, slaked lime was used containing 100 mass% of CaO.
[0020]
　Deflating behavior under load conforms to JIS R 2207-2 in a temperature range of up to 1300 ° C. from room temperature was measured under a load of 0.2 MPa. Under load inflation and deflation rate, Yu the case in the range of less than 0.5% -0.1% or more (◎), - if the range of less than 0.3% or more -0.1% or + 0.5 good cases in the range of less than% to + 0.7% (○), - the range of the case, or less than 0.7% to + 0.8% in the range of 0.5% or more and less than -0.3% If a soluble (△), - 0.5% or less than + 0.8% or more and impossible (×), was passed variable (△) or more. Incidentally, - (minus) is under load shrinkage, + (plus) means the load under inflation.
[0021]
　Hot bending strength was measured in accordance with JIS R 2213 in 1000 ° C.. Incidentally, the test piece in a furnace and held for 1 hour in order to measure temperature, to measure the hot bending strength. Hot bending strength is superior over 10MPa (◎), less than 10MPa good than 5MPa (○), allowed to 5MPa or more and less than 3 MPa (△), it was impossible (×) less than 3 MPa, the variable (△) or It was passed.
[0022]
　The overall evaluation, in the above-mentioned two evaluation, Yu (◎) Yu a case where two (◎), Yu (◎) and good (○) in the case of combined good with (○), Yu (◎) or good (○) and allowed the case of a combination of a variable (△) (△), and impossible not allowed a case where there is a (×) (×), was passed a soluble (△) or more.
[0023]
　These evaluation results are also shown in Table 1.
[0024]
[Table 1]

[0025]
　In Table 1, Examples 1-15 are all coke oven for precast block refractories in the range. Comprehensive evaluation is the variable (△) or more, expansion and contraction behavior under load, both hot flexural strength, were acceptable levels.
[0026]
　Comparative Example 1, P 2 O 5 is less example the content of the component. A sufficient bond function is obtained, the hot bending strength was less than acceptable level. On the other hand, Comparative Example 2, P 2 O 5 is higher examples the content of the component. Low melting material (SiO 2 -P 2 O 5 for) is excessively generated, deflating behavior under load is not less than acceptable level.
[0027]
　Comparative Example 3, Al 2 O 3 in the coke oven for precast block refractory mainly containing component, P as binder component 2 O 5 is an example of applying the components. The expansion and contraction behavior under load is not less than the acceptable level.
[0028]
　Comparative Example 4 is an example corresponding to the above patent document 1, an example of applying the colloidal silica and sodium silicate as a binder. Hot bending strength was less than acceptable level.
[0029]
　Comparative Example 5 is an example of using only Portland cement as a binder. The expansion and contraction behavior under load is not less than the acceptable level.
[0030]
　Further, FIG. 1 is a graph showing a load under deflated behavior from room temperature of Example 1 and Comparative Example 5 to 1300 ° C.. Phosphate (P as binder 2 O 5 Example satisfies the scope of the present invention containing a combination of component source) 1 is deflated behavior under load is stable, the Portland cement as a binding agent a large amount (5 wt%) Comparative example were formulated into 5 shrinks under significantly load from around 1000 ° C..
The scope of the claims
[Requested item 1]
　In coke ovens for precast block refractory siliceous, P 2 O 5 coke oven for precast block refractory, characterized by comprising components 2 mass% 0.3 mass% or more.
[Requested item 2]
　SiO 2 coke oven for precast block refractory according to claim 1 containing component to 99 wt% or more 65 wt%.
[Requested item 3]
　SiO 2 coke oven for precast block refractory according to claim 1 containing component 80 wt% to 99 wt% or less.
[Requested item 4]
　In the raw material compounding, coke oven for precast block refractory according to any one of claims 1 to 3 the amount of fused silica is not less than 65 mass%.
[Requested item 5]
　In the raw material mixing, 17% by weight the amount of silica or less, precast coke oven according to claim 1, any one of the 4 amount of fumed silica is less than 0.5 wt% to 15 wt% block refractory.
[Requested item 6]
　　In the raw material compounding, coke oven for precast block refractory claimed in any one of 5 the amount of the curing accelerator is less than 1.9 mass% to 0.05 mass%.
[Requested item 7]
　As a binder, a coke oven for precast block refractory according to any one of claims 1 to 6 containing no cement.