CN106630958A - Special elastic floor tile for park walk paths and manufacturing method thereof - Google Patents

Abstract

The invention relates to a special elastic floor tile for park walk paths and a manufacturing method thereof. A rubber elastomer layer is arranged on the surface of the floor tile. The manufacturing method of the floor tile comprises the following steps: mixing a base material, additives, a filler and water to obtain slurry, forming, and firing. The rubber elastomer layer is previously arranged on the surface of the floor tile, thereby preventing the tumbling people from scratches. The arranged rubber elastomer can enhance the comfort of people during walking. Due to the previously arranged rubber elastomer, the rubber elastomer layer can be directly formed on the walk path ground after the floor tiles are well laid. Compared with the existing process of finishing the ground and laying the plastic material or rubber material on the ground, the method disclosed by the invention greatly enhances the laying efficiency and saves the construction period. Meanwhile, the color of the rubber elastomer can be adjusted according to the environment of the surrounding park so as to be coordinated with the surrounding environment.

Description

A kind of resilient floor tile for being exclusively used in park pavement and preparation method thereof

Technical field

The present invention relates to the sidewalk ground tile in road construction field, specifically a kind of bullet for being exclusively used in park pavement Property floor tile and preparation method thereof.

Background technology

Floor tile is a kind of floor decorative material, is also floor tile, and most of floor tile is to be fired to form with clay, its chi Very little specification and shape are also varied, have the advantages that matter it is hard, it is pressure it is wear-resisting, can be moistureproof, and some have Jing after glazing treatment Decoration function, is used for the ground and floor of public building and civil buildings.

In actual life, typically all using floor tile laying when current pavement is laid on the meadow in park, but due to Tile surface is very hard, and old man and child easily lead to scratch when falling down, and after ground tile paving time length, due to paving If problem, the problems such as might have part floor tile and produce tilting, be more prone to cause security incident.

The content of the invention

Floor tile to solve to lay pavement in park is easily caused abrasive problem when people fall down, the invention provides A kind of resilient floor tile for being exclusively used in park pavement and preparation method thereof, the resilient floor tile is by arranging one layer of rubber in tile surface Elastomer, so as to scratch is prevented when people fall down, and due to being provided with rubber elastomer, it is also possible to when improving people's walking Comfort level；Meanwhile, the color of suitable rubber elastomer can be selected, so that itself and the perfect collocation of surrounding enviroment.

The present invention for the technical scheme that adopts of solution above-mentioned technical problem for：It is a kind of to be exclusively used in park pavement flexibly Brick, arranges one layer of rubber elastomer on the surface of floor tile, and the floor tile is mixed and made into mud by base material, additive, filler and water Slurry aftershaping, firing are formed, wherein, according to weight ratio, base material is by the flyash of 14-16 parts, the Calcium Carbide Ash of 8-10 parts, 34-38 The clay of part and the colliery powder of 5-7 parts are mixed, silicon carbide micro-powder of the additive by 9-10 parts fineness less than 30 microns, The vermiculite power of aquamaine stone powder and 0.8-1 part of 2-3 parts fineness less than 30 microns is mixed, iron mine of the filler by 4-6 parts Grinding is sintered after 2h after the red mud mixing of waste residue, the slag of 3-4 parts and 2-3 parts at a temperature of 1650-1700 DEG C to fineness not Obtain more than 30 microns.

Talcum powder in the additive also containing 1-2 parts fineness less than 100 microns.

Dolomite powder in the filler also containing 1-2 parts.

The filler in preparation process, after rapidly being cooled down with the rate of temperature fall of 600-700 DEG C/min after the completion of sintering Grinding is carried out again.

The manufacture method of the above-mentioned resilient floor tile for being exclusively used in park pavement, prepares filler powder first, then above-mentioned ratio Example weighs each material and carries out being mixed and added into water makes the pug that moisture content is 18-20%, and the pug is made after 6-8 days in ageing Floor tile base substrate, then drying, sintering and natural cooling obtain floor tile, finally floor tile surface laying rubber elastomer be Product is obtained, the preparation method of the filler powder is：Iron mine waste residue, slag and red mud are weighed according to above-mentioned ratio, is mixed Fine powder of the grinding to fineness less than 300 microns after conjunction, cooling grinding after then sintering 2h at a temperature of 1650-1700 DEG C Filler is obtained less than 30 microns to fineness.

The pug after ageing 6-8 days is added thereto to the waste oil of pug gross weight 2%, enters after mix is uniform again again Row extrusion molding makes floor tile base substrate.

The drying temperature is 100-120 DEG C.

The sintering is divided into preheating section, three part of warming-up section and furnace zone, wherein, preheating section is to instigate in-furnace temperature from normal Temperature is uniformly increased to 200 DEG C in 2h, and keeps temperature 1-2h, and in the process, in holding furnace, oxygen content is not higher than 4%；

The warming-up section refers to, makes in-furnace temperature uniformly be increased to 800 DEG C in 4h from 200 DEG C, in the process, oxygen in holding furnace Gas content is not less than 45%；

The furnace zone refers to, makes in-furnace temperature uniformly be increased to 1650 DEG C in 2h from 800 DEG C, and keep temperature 3h, here During, in holding furnace, oxygen content is not less than 45%.

In the present invention, when floor tile is made, to prevent from occurring the defects such as crackle in floor tile sintering process, each material is being mixed After pug ageing is made in conjunction, the cement that can be added thereto to base material gross weight 8% carries out mix, carry out again drying after mix is uniform, Sintering and cooling, so as to finally give floor tile.

In the present invention, the rubber elastomer can be made up of following material：According to weight ratio, the rubber elastomer by 26～28 parts of nitrile rubber, 10～12 parts of polyester fiber, 3～4 parts of vulcanizing agent, 3～4 parts of modified hollow glass are micro- Pearl, 2～3 parts of fine silica powder, 0.8～1 part of modified Potassium Tetratitanate Whisker and 4～6 parts of reinforcing agent are at 60～80 DEG C Under the conditions of knead and form, the reinforcing agent by 8～10 parts of sepiolite cashmeres, 1～2 part of modified nano-titanium dioxide, 10～12 parts Tetraethyl orthosilicate is made；The modified hollow glass micro-ball and modified Potassium Tetratitanate Whisker are respectively will be commercially available hollow glass micro- Ball and commercially available Potassium Tetratitanate Whisker are filtered to dry after standing 1-2h after being mixed with the surface modifier of its weight 3-5% and are obtained, institute Compare 3-4 according to weight by KH550, ethanol, acetone and barium hydroxide with surface modifier:80:2-3:1-2 ratio mixing and Into；

The preparation method of wherein reinforcing agent is：According to weight ratio, 10～12 parts of tetraethyl orthosilicates and deionized water are taken according to 1:8- 10 ratio mixing, then the glacial acetic acid of tetraethyl orthosilicate weight 10%, the carbon of tetraethyl orthosilicate weight 5% are sequentially added thereto Powder, the modified nano-titanium dioxide mix homogeneously of 8～10 parts of sepiolite cashmeres and 1～2 part are reacted, in course of reaction, every 20min applies the ultrasound wave 1min of frequency 350-370kHz into reaction system, and question response surpasses to reaction system after terminating Filter obtains pressed powder, and finally by pressed powder, under aerobic conditions, abundant calcination removing carbon dust obtains reinforcing agent；It is described to change Property nano titanium oxide be that commercially available nano titanium oxide is mixed to get with the surface modifier of its weight 3-5%, the surface be modified Agent compares 3-4 according to weight by barium hydroxide, sodium carbonate and KH550:1-2:30 ratio is mixed.

In the rubber elastomer of above-mentioned special composition, containing modified hollow glass micropearl, on the one hand can be dispersed in In the matrix that nitrile rubber and polyester fiber are formed, on the other hand it is to make hollow glass micropearl surface grafting a large amount of in modifying process Silicone hydroxyl, hollow glass micropearl coupled together with matrix by these groups by chemical reaction, it is ensured that the two has good Interface binding power, when by external force, hollow glass micropearl particle is stressed and deforms upon, destroys material in the material, So as to apparatus with shock absorbing, impact property is improved, while crazing can also be caused, terminate crack extension, in certain morphosiss The lower shear yielding for causing matrix, so as to consume substantial amounts of impact energy, can preferably transmit born external force again, improve rubber The compressive strength of glue elastomer, bending strength, impact strength；The sepiolite cashmere for containing also has microcellular structure, with very big Specific surface area, can also absorb vibrations and impact in being distributed to rubber elastomer；

Nano level SiO is allowed as catalyst by the use of barium hydroxide and sodium carbonate mixing₂The surface energy of particle is hard to bear to arrive hydroxyl Effect, so as to contain a number of oxygen-containing functional group, increased nanoscale SiO₂The relevant surface compatability of particle, in nanometer Level SiO₂When particle is sufficiently mixed as inserts and remaining raw material, because SiO₂Granule very little, and specific surface area is big, granular Structure rest materials are increased with its contact area, make SiO₂Particle can be dispersed in material, consequently facilitating SiO₂There is chemical bonding or physical bond at high temperature with remaining material.Additionally, homodisperse nanoscale SiO₂Equivalent to " anchor point ", which can make the reinforcing matrix generated under hot environment in connection, under by external impacts effect, can produce The effect of " stress concentration " so that some matrixes " surrender " around which simultaneously absorb more work of deformation, can also produce in addition " pinning-climb up and over " effect, increases the crackle resistance suffered in extension, consumes work of deformation, so that its toughness increases.

The present invention is used as firing the base material of floor tile with flyash, Calcium Carbide Ash, clay and colliery powder, not only solves powder The recycling of coal ash, Calcium Carbide Ash and gangue the like waste, and also improve the intensity of floor tile after firing（The oxidation for containing Ceramic particle Reinforcement structure is formed in the hot environment with calcium oxide when floor tile is sintered such as aluminum, silicon oxide）, by add by Carborundum can cause the tile surface for burning till to contain some opening pores as additive（Or claim open pore）, these Pore ensure that the compactness combined with rubber elastomer by floor tile, nor can affect the intensity of floor tile；Carborundum is in height Oxidation reaction is susceptible in warm oxidizing atmosphere：SiC+2O₂→CO₂+SiO₂, the reaction started temperature is higher, and 1000 DEG C of beginnings are bright Aobvious oxidation, granule are thinner, then oxidation rate is faster, product CO₂Effusion easily cause billet surface formed open pore, And product SiO₂With greater activity, mullite is generated with oxidation reactive aluminum, strengthen so as to form mullite in floor tile Body；Meanwhile, the kyanite fine powder under high temperature in additive decomposes, and both can ensure that and generates more mullite phase, it is ensured that product Mechanical strength, kyanite start to decompose from 1100 DEG C or so, generate mullite and SiO₂, 1300 DEG C of notable decomposition and inversion later, As the mullitization reaction is with the volumetric expansion of 16-18%, therefore can also fill the hole produced due to Oxidation of SiC Gap, makes single hole diminish, and overall porosity is reduced, and can change shape and the distribution of floor tile inner pore；Due in floor tile Containing substantial amounts of micropore, it is also possible to absorb and weaken the transmission of vibrations；

Beneficial effect：The present invention compared with prior art, with advantages below：

1）The present invention prevents scratch by pre-setting one layer of rubber elastomer on the surface of floor tile, not only when people fall down, And due to being provided with rubber elastomer, comfort level when people walk can be improved, simultaneously as pre-setting caoutchouc elasticity Body so that ground tile paving well after one layer of rubber elastomer is directly formed on footpath ground, with it is existing first arrange ground, Then plastic material being spread on the ground or the method for elastomeric material being compared, the efficiency of laying is greatly improved, construction is saved Duration；Meanwhile, the color of rubber elastomer can be adjusted according to the environment in park around, so which is with surrounding enviroment more Collocation and coordination；

2）The present invention is used as firing the base material of floor tile with flyash, Calcium Carbide Ash, clay and colliery powder, not only solves fine coal The recycling of ash, Calcium Carbide Ash and gangue the like waste, and also improve the intensity of floor tile after firing（The aluminium oxide that contains, Ceramic particle Reinforcement structure is formed in the hot environment with calcium oxide when floor tile is sintered such as silicon oxide）, by adding by carbon SiClx can cause the tile surface for burning till to contain some opening pores as additive（Or claim open pore）, these gas Hole ensure that the compactness combined with rubber elastomer by floor tile, nor can affect the intensity of floor tile；

3）Kyanite fine powder in additive of the present invention decomposes at high temperature, both can ensure that and has generated more mullite phase, it is ensured that The mechanical strength of product, kyanite start to decompose from 1100 DEG C or so, generate mullite and SiO₂, 1300 DEG C are significantly decomposed later Conversion, as the mullitization reaction is with the volumetric expansion of 16-18%, therefore can also fill due to Oxidation of SiC generation Hole, make single hole diminish, overall porosity is reduced, and can change shape and the distribution of floor tile inner pore；

4）The present invention after pug ageing is added thereto to waste oil and carries out mix, not only takes full advantage of discarded waste oil, And due to adding waste oil so that the stickiness of pug and moulding strengthened, so that additive decomposes at high temperature During forming pore, it is greatly lowered due to the defect such as crackle caused by pore and aquamaine stone powder expansion institute.

Specific embodiment

Technical scheme is further elaborated with reference to specific embodiment.

Embodiment 1

A kind of resilient floor tile for being exclusively used in park pavement, arranges one layer of rubber elastomer on the surface of floor tile, and the floor tile is by base Material, additive, filler and water are mixed and made into mud aftershaping, firing and form, wherein, according to weight ratio, base material is by 14 parts Flyash, 8 parts of Calcium Carbide Ash, the colliery powder of 34 parts of clay and 5 parts are mixed, and additive is less than 30 by 9 parts of fineness The vermiculite power of the silicon carbide micro-powder of micron, 2 parts of fineness aquamaine stone powder and 0.8 part less than 30 microns is mixed, filler By grinding after sintering 2h at a temperature of 1650 DEG C after the red mud mixing of 4 parts of iron mine waste residue, 3 parts of slag and 2 parts to fineness Obtain less than 30 microns；

The manufacture method of the above-mentioned resilient floor tile for being exclusively used in park pavement, prepares filler powder first, and then aforementioned proportion claims Take each material and carry out being mixed and added into water and make the pug that moisture content is 18%, the pug makes floor tile base substrate after 6 days in ageing, Then drying, sintering and natural cooling obtain floor tile, and finally the surface laying rubber elastomer in floor tile obtains product, The preparation method of the filler powder is：Iron mine waste residue, slag and red mud are weighed according to above-mentioned ratio, after mixing grinding is extremely Fine powder of the fineness less than 300 microns, after then sintering 2h at a temperature of 1650 DEG C, simultaneously grinding is less than 30 to fineness for cooling Micron obtains filler.

Above for the present embodiment basic embodiment, can more than on the basis of further improved, optimized and limited：

Such as, the Talcum powder in the additive also containing 1 part of fineness less than 100 microns；

And for example, also containing 1 part of dolomite powder in the filler；

And for example, the filler enters after rapidly being cooled down with the rate of temperature fall of 600 DEG C/min after the completion of sintering in preparation process again Row grinding；

For another example, the pug after ageing 6 days is added thereto to the waste oil of pug gross weight 2%, enters after mix is uniform again again Row extrusion molding makes floor tile base substrate；

Again for another example, the drying temperature is 100 DEG C, and axial flow blower is made full use of in drying course, so as to be heated evenly；

Finally, it is described sintering be divided into preheating section, three part of warming-up section and furnace zone, wherein, preheating section be instigate in-furnace temperature from Room temperature is uniformly increased to 200 DEG C in 2h, and keeps temperature 1h, and in the process, in holding furnace, oxygen content is not higher than 4%；

The warming-up section refers to, makes in-furnace temperature uniformly be increased to 800 DEG C in 4h from 200 DEG C, in the process, oxygen in holding furnace Gas content is not less than 45%；

The furnace zone refers to, makes in-furnace temperature uniformly be increased to 1650 DEG C in 2h from 800 DEG C, and keep temperature 3h, here During, in holding furnace, oxygen content is not less than 45%.

Embodiment 2

A kind of resilient floor tile for being exclusively used in park pavement, arranges one layer of rubber elastomer on the surface of floor tile, and the floor tile is by base Material, additive, filler and water are mixed and made into mud aftershaping, firing and form, wherein, according to weight ratio, base material is by 16 parts Flyash, 10 parts of Calcium Carbide Ash, the colliery powder of 38 parts of clay and 7 parts are mixed, and additive is less than by 10 parts of fineness The vermiculite power of 30 microns of silicon carbide micro-powder, 3 parts of fineness aquamaine stone powder and 1 part less than 30 microns is mixed, filler By grinding after sintering 2h at a temperature of 1700 DEG C after the red mud mixing of 6 parts of iron mine waste residue, 4 parts of slag and 3 parts to fineness Obtain less than 30 microns；

The manufacture method of the above-mentioned resilient floor tile for being exclusively used in park pavement, prepares filler powder first, and then aforementioned proportion claims Take each material and carry out being mixed and added into water and make the pug that moisture content is 20%, the pug makes floor tile base substrate after 8 days in ageing, Then drying, sintering and natural cooling obtain floor tile, and finally the surface laying rubber elastomer in floor tile obtains product, The preparation method of the filler powder is：Iron mine waste residue, slag and red mud are weighed according to above-mentioned ratio, after mixing grinding is extremely Fine powder of the fineness less than 300 microns, after then sintering 2h at a temperature of 1700 DEG C, simultaneously grinding is less than 30 to fineness for cooling Micron obtains filler.

Above for the present embodiment basic embodiment, can more than on the basis of further improved, optimized and limited：

Such as, the Talcum powder in the additive also containing 2 parts of fineness less than 100 microns；

And for example, also containing 2 parts of dolomite powder in the filler；

And for example, the filler enters after rapidly being cooled down with the rate of temperature fall of 700 DEG C/min after the completion of sintering in preparation process again Row grinding；

For another example, the pug after ageing 8 days is added thereto to the waste oil of pug gross weight 2%, enters after mix is uniform again again Row extrusion molding makes floor tile base substrate；

Again for another example, the drying temperature is 120 DEG C, and axial flow blower is made full use of in drying course, so as to be heated evenly；

Finally, it is described sintering be divided into preheating section, three part of warming-up section and furnace zone, wherein, preheating section be instigate in-furnace temperature from Room temperature is uniformly increased to 200 DEG C in 2h, and keeps temperature 2h, and in the process, in holding furnace, oxygen content is not higher than 4%；

The warming-up section refers to, makes in-furnace temperature uniformly be increased to 800 DEG C in 4h from 200 DEG C, in the process, oxygen in holding furnace Gas content is not less than 45%；

The furnace zone refers to, makes in-furnace temperature uniformly be increased to 1650 DEG C in 2h from 800 DEG C, and keep temperature 3h, here During, in holding furnace, oxygen content is not less than 45%.

Embodiment 3

A kind of resilient floor tile for being exclusively used in park pavement, arranges one layer of rubber elastomer on the surface of floor tile, and the floor tile is by base Material, additive, filler and water are mixed and made into mud aftershaping, firing and form, wherein, according to weight ratio, base material is by 15 parts Flyash, 9 parts of Calcium Carbide Ash, the colliery powder of 36 parts of clay and 6 parts are mixed, and additive is less than by 9.5 parts of fineness The vermiculite power of 30 microns of silicon carbide micro-powder, 2.5 parts of fineness aquamaine stone powder and 0.9 part less than 30 microns is mixed, and is filled out Fill agent by powder after 2h being sintered at a temperature of 1675 DEG C after 5 parts of iron mine waste residue, the red mud mixing of 3.5 parts of slag and 2.5 parts It is milled to fineness to obtain less than 30 microns；

The manufacture method of the above-mentioned resilient floor tile for being exclusively used in park pavement, prepares filler powder first, and then aforementioned proportion claims Take each material and carry out being mixed and added into water and make the pug that moisture content is 19%, the pug makes ground adobe after 6-8 days in ageing Body, then drying, sintering and natural cooling obtain floor tile, finally floor tile surface laying rubber elastomer produced Product, the preparation method of the filler powder is：Iron mine waste residue, slag and red mud are weighed according to above-mentioned ratio, powder after mixing Fine powder of the fineness less than 300 microns is milled to, and after then 2h being sintered at a temperature of 1675 DEG C, simultaneously grinding does not surpass to fineness for cooling Cross 30 microns and obtain filler.

Above for the present embodiment basic embodiment, can more than on the basis of further improved, optimized and limited：

Such as, the Talcum powder in the additive also containing 1.5 parts of fineness less than 100 microns；

And for example, also containing 1.5 parts of dolomite powder in the filler；

And for example, the filler enters after rapidly being cooled down with the rate of temperature fall of 650 DEG C/min after the completion of sintering in preparation process again Row grinding；

For another example, the pug after ageing 7 days is added thereto to the waste oil of pug gross weight 2%, enters after mix is uniform again again Row extrusion molding makes floor tile base substrate；

Again for another example, the drying temperature is 110 DEG C, and axial flow blower is made full use of in drying course, so as to be heated evenly；

Finally, it is described sintering be divided into preheating section, three part of warming-up section and furnace zone, wherein, preheating section be instigate in-furnace temperature from Room temperature is uniformly increased to 200 DEG C in 2h, and keeps temperature 1.5h, and in the process, in holding furnace, oxygen content is not higher than 4%；

The warming-up section refers to, makes in-furnace temperature uniformly be increased to 800 DEG C in 4h from 200 DEG C, in the process, oxygen in holding furnace Gas content is not less than 45%；

The furnace zone refers to, makes in-furnace temperature uniformly be increased to 1650 DEG C in 2h from 800 DEG C, and keep temperature 3h, here During, in holding furnace, oxygen content is not less than 45%.

Claims (8)

1. a kind of resilient floor tile for being exclusively used in park pavement, arranges one layer of rubber elastomer on the surface of floor tile, it is characterised in that： The floor tile is mixed and made into mud aftershaping, firing by base material, additive, filler and water and forms, wherein, according to weight ratio, Base material is mixed by the colliery powder of the flyash of 14-16 parts, the Calcium Carbide Ash of 8-10 parts, the clay of 34-38 parts and 5-7 parts, Additive by 9-10 parts fineness less than 30 microns silicon carbide micro-powder, 2-3 parts fineness less than 30 microns aquamaine stone powder and The vermiculite power of 0.8-1 parts is mixed, and filler is mixed by the red mud of the iron mine waste residue, the slag of 3-4 parts and 2-3 parts of 4-6 parts After 2h is sintered at a temperature of 1650-1700 DEG C afterwards, grinding is obtained to fineness less than 30 microns.

2. a kind of resilient floor tile for being exclusively used in park pavement according to claim 1, it is characterised in that：In the additive Talcum powder also containing 1-2 parts fineness less than 100 microns.

3. a kind of resilient floor tile for being exclusively used in park pavement according to claim 1, it is characterised in that：In the filler Dolomite powder also containing 1-2 parts.

4. a kind of resilient floor tile for being exclusively used in park pavement according to claim 1, it is characterised in that：The filler exists In preparation process, grinding after rapidly cooling down with the rate of temperature fall of 600-700 DEG C/min after the completion of sintering, is carried out again.

5. a kind of manufacture method of resilient floor tile for being exclusively used in park pavement according to claim 1, prepares filling first Agent powder, then according to it is 18-20%'s that the ratio of claim 1 weighs each material and carries out be mixed and added into water making moisture content Pug, the pug make floor tile base substrate after being aged 6-8 days, and then drying, sintering and natural cooling obtain floor tile, finally Product is obtained in the surface laying rubber elastomer of floor tile, it is characterised in that the preparation method of the filler powder is：Press Iron mine waste residue, slag and red mud are weighed according to the ratio described in claim 1, grinding is less than 300 microns to fineness after mixing Fine powder, after then sintering 2h at a temperature of 1650-1700 DEG C, simultaneously grinding is filled to fineness less than 30 microns for cooling Agent.

6. the manufacture method of a kind of resilient floor tile for being exclusively used in park pavement according to claim 5, it is characterised in that：Institute Pug is stated after ageing 6-8 days, the waste oil of pug gross weight 2% is added thereto to, after mix is uniform again, is carried out extrusion molding again Make floor tile base substrate.

7. the manufacture method of a kind of resilient floor tile for being exclusively used in park pavement according to claim 5, it is characterised in that：Institute Drying temperature is stated for 100-120 DEG C.

8. the manufacture method of a kind of resilient floor tile for being exclusively used in park pavement according to claim 5, it is characterised in that：Institute State sintering and be divided into preheating section, three part of warming-up section and furnace zone, wherein, preheating section is to instigate in-furnace temperature uniform in 2h from room temperature 200 DEG C are increased to, and keep temperature 1-2h, in the process, oxygen content is not higher than 4% in holding furnace；

The warming-up section refers to, makes in-furnace temperature uniformly be increased to 800 DEG C in 4h from 200 DEG C, in the process, oxygen in holding furnace Gas content is not less than 45%；

The furnace zone refers to, makes in-furnace temperature uniformly be increased to 1650 DEG C in 2h from 800 DEG C, and keep temperature 3h, here During, in holding furnace, oxygen content is not less than 45%.