阅读说明：本技术 一种高抗压强度发泡陶瓷的制备方法 (A kind of preparation method of high compressive strength foamed ceramic ) 是由 朱祥辉 于 2019-08-19 设计创作，主要内容包括：本发明公开了一种高抗压强度发泡陶瓷的制备方法,其依次包括：混料、球磨、喷雾造粒,筛分得到不同粒径范围的不同粉料,将不同粉料按照特定顺序布料到高温匣钵中,将高温匣钵置于窑炉中,按照预设烧成曲线烧成,得到高抗压强度发泡陶瓷成品。本发明通过对于布料方式的变化,提升了热量传导效率,减小了温度梯度；并通过调整烧成曲线,有效控制了发泡陶瓷中气泡相的结构,进而达到高强度与低导热系数的统一。(The invention discloses a kind of preparation methods of high compressive strength foamed ceramic, it successively includes: mixing, ball milling, mist projection granulating, screening obtains the different powders of different-grain diameter range, different powders are expected in high temperature sagger according to particular order cloth, high temperature sagger is placed in kiln, it is burnt into according to default sintering curve, obtains high compressive strength foamed ceramic finished product.The present invention improves heat conduction efficiency, reduces temperature gradient by the variation for distributing mode；And by adjusting sintering curve, the structure of bubble phase in foamed ceramic is effectively controlled, and then reaches the high-intensitive unification with low thermal conductivity.)

1. a kind of preparation method of high compressive strength foamed ceramic characterized by comprising

(1) various raw materials are uniformly mixed according to formula, obtain mixture；

(2) mixture is subjected to ball milling, obtains slurry；

(3) slurry is subjected to mist projection granulating, obtains powder；

(4) powder is sieved, obtain 20 the first powder of purpose of granularity >, granularity be 20~80 the second powders of purpose and The third powder of 80 mesh of granularity <；

(5) by the third powder, the first powder and the second powder, successively cloth is expected in high temperature sagger；

(6) high temperature sagger is placed in kiln, according to default sintering curve be burnt into, obtain high compressive strength foamed ceramic at Product；

Wherein, the sintering curve are as follows:

From room temperature to 1000 DEG C, using the heating rate of 700~800 DEG C/h；

From 1000 DEG C to firing temperature, using the heating rate of 400~550 DEG C/h；

1~1.5h is kept the temperature in firing temperature；

From firing temperature to 600 DEG C, using the rate of temperature fall of 500~800 DEG C/h；

From 600 DEG C to room temperature, using the rate of temperature fall of 300~500 DEG C/h.

2. the preparation method of high compressive strength foamed ceramic as described in claim 1, which is characterized in that described in step (4) The weight of first powder: the weight of the second powder: weight=1:(3~5 of third powder): (1.5~4).

3. the preparation method of high compressive strength foamed ceramic as claimed in claim 2, which is characterized in that the firing temperature is 1140~1160 DEG C, firing period is 5~8h.

4. the preparation method of high compressive strength foamed ceramic as claimed in claim 3, which is characterized in that in step (5), first will Third powder cloth is expected in high temperature sagger, forms first bed of material, then expects the first powder cloth on first bed of material, is formed Second bed of material, then the second powder cloth is expected on second bed of material, form the third bed of material；

First thickness of feed layer: the second thickness of feed layer: third thickness of feed layer=(1.2~2.5): 1:(1.8~3).

5. the preparation method of high compressive strength foamed ceramic as claimed in claim 4, which is characterized in that the high compressive strength The formula of foamed ceramic in parts by weight are as follows:

50~65 parts of the red tailing in Luoyuan, 30~35 parts of steel mill's grain slag, 3~10 parts of clay, 0~5 part of foaming agent, binder 0.1~3 Part；

The sum of each raw material component parts by weight are 100 parts.

6. the preparation method of high compressive strength foamed ceramic as claimed in claim 5, which is characterized in that steel mill's grain slag master It consists of the following components in percentage by weight: SiO₂25~30%, Al₂O₃26~30%, Fe₂O₃0.5~1.5%, TiO₂ 0.1~0.7%, CaO 22~25%, MgO 8~9%, K₂O 0.1~0.5%, Na₂O0.2~1%, MnO₂2~4%, SO₃ 1~2, Cr₂O₃1.5~3%.

7. the preparation method of high compressive strength foamed ceramic as claimed in claim 5, which is characterized in that clay selection black mud, One of mud washing, harbour road mud or ooze are a variety of.

8. the preparation method of high compressive strength foamed ceramic as claimed in claim 5, which is characterized in that the foaming agent is selected One of silicon carbide, carbon dust or ceramic abrading block reclaimed materials are a variety of；The stabilizer selects manganese dioxide.

9. the preparation method of high compressive strength foamed ceramic as claimed in claim 5, which is characterized in that the binder is selected One of sodium carboxymethylcellulose pyce, sodium carboxymethylcellulose, waterglass, polyacrylamide are a variety of.

10. the preparation method of high compressive strength foamed ceramic as described in claim 1, which is characterized in that the high pressure resistance Compression strength >=10MPa of foamed ceramic is spent, bulk density is 150~200kg/m³, water absorption rate≤0.5%, thermal coefficient is ≤0.08W/m·K。

Technical field

The present invention relates to field of inorganic nonmetallic material more particularly to a kind of preparation sides of high compressive strength foamed ceramic Method.

Background technique

Foamed ceramic is a kind of New Building Materials, internal to have a large amount of sealed porosity, therefore has lightweight heat-proof The advantages of heat preservation；Meanwhile existing foamed ceramic for building mostly uses ceramic tile factory polished waste material or other waste (such as granite Waste material, flyash etc.) it is used as base-material, advantageously account for solid waste pollution problem.Therefore, foamed ceramic has extremely wide application Prospect.But existing foamed ceramic compression strength for building low (generally in 0.5~2MPa), thermal coefficient is higher (generally exists 0.1W/mK or so), it limits its application.

According to the common sense of those skilled in the art, the intensity of foamed ceramic depend primarily on foamed ceramic formula and Bubble phase in its structure, wherein control bubble phase morphology is most important: when in bubble phase containing a large amount of random air pockets, The compression strength of foamed ceramic can be reduced；Or it when bubble phase size distribution is uneven, also be easy to cause under compression strength Drop；Or when containing excessive bubble phase in foamed ceramic, it will also result in the decline of compression strength.And on the other hand, work as hair When bubble phase content is promoted in bubble ceramics, thermal coefficient decline, the optimization of heat preservation and soundproof performance.Therefore, low thermal conductivity and highly resistance Compressive Strength, low water absorption are usually that can not get both.

Chinese patent CN109053214A discloses a kind of technique of layering treatment cloth production foamed ceramic, will be a variety of Oxygenate content and grain graininess are all different foamed ceramic particulate material, then produce foamed ceramic material by layer-by-layer distribution. Such set-up mode is additionally favorable for the transmitting of heat, and the foaming for making up temperature gradient generation is uneven, and it is random to reduce foamed ceramic The probability that bulla occurs.But its preparation process is complicated, firing period is long.

Summary of the invention

The present invention also technical problems to be solved are, provide a kind of preparation side of above-mentioned high compressive strength foamed ceramic Method, the foamed ceramic thermal coefficient being prepared is low, compression strength is high, water absorption rate is low.

In order to solve the above-mentioned technical problems, the present invention provides a kind of preparation method of high compressive strength foamed ceramic, Include:

(1) various raw materials are uniformly mixed according to formula, obtain mixture；

(2) mixture is subjected to ball milling, obtains slurry；

(3) slurry is subjected to mist projection granulating, obtains powder；

(4) powder is sieved, obtains 20 the first powder of purpose of granularity >, granularity is 20~80 the second powder of purpose The third powder of material and 80 mesh of granularity <；

(5) by the third powder, the first powder and the second powder, successively cloth is expected in high temperature sagger；

(6) high temperature sagger is placed in kiln, is burnt into according to default sintering curve, obtains high compressive strength foamed ceramic Finished product；

Wherein, the sintering curve are as follows:

From room temperature to 1000 DEG C, using the heating rate of 700~800 DEG C/h；

From 1000 DEG C to firing temperature, using the heating rate of 400~550 DEG C/h；

1~1.5h is kept the temperature in firing temperature；

From firing temperature to 600 DEG C, using the rate of temperature fall of 500~800 DEG C/h；

From 600 DEG C to room temperature, using the rate of temperature fall of 300~500 DEG C/h.

As an improvement of the above technical solution, in step (4), the weight of first powder: the weight of the second powder: the Weight=1:(3~5 of three powders): (1.5~4).

As an improvement of the above technical solution, the firing temperature is 1140~1160 DEG C, and firing period is 5~8h.

As an improvement of the above technical solution, in step (5), first third powder cloth is expected in high temperature sagger, forms the Then one bed of material is expected the first powder cloth on first bed of material, form second bed of material, then the second powder cloth is expected On second bed of material, the third bed of material is formed；

First thickness of feed layer: the second thickness of feed layer: third thickness of feed layer=(1.2~2.5): 1:(1.8~3).

As an improvement of the above technical solution, the formula of the high compressive strength foamed ceramic in parts by weight are as follows:

50~65 parts of the red tailing in Luoyuan, 30~35 parts of steel mill's grain slag, 3~10 parts of clay, 0~5 part of foaming agent, binder 0.1~3 part；

The sum of each raw material component parts by weight are 100 parts.

As an improvement of the above technical solution, steel mill's grain slag mainly consists of the following components in percentage by weight: SiO₂25~30%, Al₂O₃26~30%, Fe₂O₃0.5~1.5%, TiO₂0.1~0.7%, CaO 22~25%, MgO 8~9%, K₂O 0.1~0.5%, Na₂O 0.2~1%, MnO₂2~4%, SO₃1~2, Cr₂O₃1.5~3%.

As an improvement of the above technical solution, the clay select one of black mud, mud washing, harbour road mud or ooze or It is a variety of.

As an improvement of the above technical solution, the foaming agent is selected in silicon carbide, carbon dust or ceramic abrading block reclaimed materials It is one or more；The stabilizer selects manganese dioxide.

As an improvement of the above technical solution, the binder selects sodium carboxymethylcellulose pyce, sodium carboxymethylcellulose, water glass One of glass, polyacrylamide are a variety of.

As an improvement of the above technical solution, compression strength >=10MPa of the high compressive strength foamed ceramic, volume are close Degree is 150~220kg/m³, water absorption rate≤0.5%, thermal coefficient is≤0.08W/mK.

The invention has the following beneficial effects:

1. the present invention sieves powder after granulation, the different powders of different-grain diameter range are formed, and then using specific Cloth sequence carry out cloth；The heat conduction efficiency of green body obtained by cloth is improved, temperature gradient is reduced, effectively controls The structure of bubble phase in foamed ceramic, improves the compression strength of foamed ceramic, while but also thermal coefficient maintain it is lower Level.

2. the present invention is effectively controlled in foamed ceramics and is closed by the Collaborative Control for distributing technique and sintering curve The structure of stomata significantly improves the compression strength of foamed ceramic；It is relatively low to also ensure that foamed ceramic has simultaneously Thermal coefficient (≤0.07W/mK).

Detailed description of the invention

Fig. 1 is a kind of preparation method flow chart of high compressive strength foamed ceramic of the present invention.

Specific embodiment

To make the object, technical solutions and advantages of the present invention clearer, the present invention is made into one below in conjunction with attached drawing Step ground detailed description.Only this is stated, the present invention occurs in the text or will occur up, down, left, right, before and after, it is inside and outside etc. just Position word is not to specific restriction of the invention only on the basis of attached drawing of the invention.

With reference to Fig. 1, the present invention provides a kind of preparation methods of high compressive strength foamed ceramic brick comprising following step It is rapid:

S1: various raw materials are uniformly mixed according to formula, obtain mixture；

S2: the mixture is subjected to ball milling, obtains slurry；

Specifically, control slurry ball milling fineness is that 250 meshes tail over < 0.5%.

S3: the slurry is subjected to mist projection granulating, obtains powder；

S4: sieving the powder, obtains varigrained powder；

Specifically, sieve to the powder, 20 the first powder of purpose of granularity > is obtained, granularity is 20~80 purposes the The third powder of 80 mesh of two powders and granularity <；

Preferably, the weight of the first powder: the weight of the second powder: weight=1:(3~5 of third powder): (1.5~ 4).Preferably, the weight of the first powder: the weight of the second powder: weight=1:(3~5 of third powder): (1.5~4).

S5: varigrained powder is expected in high temperature sagger by particular order cloth；

Specifically, first expecting third powder cloth in high temperature sagger, first bed of material is formed, then expects the first powder cloth On first bed of material, second bed of material is formed, then the second powder cloth is expected on second bed of material, forms third material Layer.

The present invention is by being arranged in two sides for the lesser third powder of partial size and the second powder, by biggish first powder of partial size Material is arranged in centre；Heat is effectively conducted from two sides to center, temperature gradient is reduced, so that foaming is more equal It is even；Meanwhile but also higher firing speed can be used in the subsequent process, to reach bubble in control foamed ceramic Phase reaches the high-intensitive unification with low thermal conductivity.

It should be noted that also proposed similar technical solution of the present invention in existing literature CN109053214A, By the lesser particulate material of partial size incessantly in lower layer, the biggish particle of partial size is incessantly on upper layer；It is low to reduce temperature gradient Temperature exhaust provides channel.However, present inventor has found in the course of the research, the temperature conduction in sintering process is more It is and the conduction by lower layer to upper layer not proposed in existing literature from two sides to center.And inventor passes through many experiments Prove: the temperature on the upside of green body is less than the temperature on the downside of green body, therefore the second thicker powder of granularity is arranged in by the present invention Upside, and the most thin third powder of granularity is arranged in the bottom.By above-mentioned distributing mode, so that the temperature ladder in the present invention Degree is smaller, and more quick heating process can be used in subsequent firing process.In addition, in the prior art, it is also necessary to increase Add additional roll-in prilling, and the present invention then improves granulation performance by the change to Recipe, without additional roller Pressure is granulated.

Preferably, first thickness of feed layer: the second thickness of feed layer: third thickness of feed layer=(1.2~2.5): 1:(1.8 ~3).Each thick layer of this ratio has the effect of preferably reducing temperature gradient.

S6: being placed in kiln for the high temperature sagger, is burnt into according to default sintering curve, obtains high compressive strength foamed ceramic Finished product.

Specifically, the sintering curve are as follows:

From room temperature to 1000 DEG C, using the heating rate of 700~800 DEG C/h；

From 1000 DEG C to firing temperature, using the heating rate of 400~550 DEG C/h；

1~1.5h is kept the temperature in firing temperature；

From firing temperature to 600 DEG C, using the rate of temperature fall of 500~800 DEG C/h；

From 600 DEG C to room temperature, using the rate of temperature fall of 300~500 DEG C/h；

The present invention, hereinafter, using faster heating rate, so that air pressure release is fast in high-temperature liquid-phase, forms bubble at 1000 DEG C Cuclear density is big, and aperture reduces, and open porosity (water absorption rate) reduces, and the void count on hole wall is reduced, and significantly promotes hair Steep the compression strength of ceramics.According to experiment, when using the heating rate of 200 DEG C/h, the compression strength of foamed ceramic only 0.9~ 1.18MPa, and will heat up rate and be promoted to 700 DEG C/h, that is, it may make compression strength to improve to 10.4~12.5MPa.Work as heating Rate is greater than 800 DEG C/h, and the organic matter in mineral can not decompose in time, will cause various defects.It should be noted that only existing Under the premise of using the above-mentioned powder processed of the present invention and distributing technique, it can just will heat up rate and promote quoad hoc.

After 1000 DEG C of temperature >, heating rate is suitably reduced, foaming agent (SiC) and MnO can be effectively facilitated₂Sufficiently point Solution, reduces the thermal coefficient of foamed ceramic.Preferably, from 1000 DEG C to firing temperature, using 400~500 DEG C of heating rate. Further, 1~1.5h is kept the temperature in firing temperature, soaking time is appropriately extended, can promote abundant point of clay pit phase in green body Solution is precipitated mullite crystal, promotes the compression strength of foamed ceramic.

In temperature-fall period, from firing temperature to 600 DEG C, using the rate of temperature fall of 500~800 DEG C/h, this rate of temperature fall can Ensure that the crystal in high-temperature fusant is sufficiently precipitated, strengthens foamed ceramic.From 600 DEG C to room temperature, using 300~500 DEG C of cooling Rate.

Preferably, the firing temperature is 1140~1160 DEG C, and firing period is 5~8h.

Correspondingly, in order to cooperate above-mentioned preparation method, it is also necessary to be optimized to the formula of foamed ceramic:

Specifically, in the present invention, the formula of high compressive strength foamed ceramic brick in parts by weight are as follows:

50~65 parts of the red tailing in Luoyuan, 30~35 parts of steel mill's grain slag, 3~10 parts of clay, 0~5 part of foaming agent, binder 0.1~3 part；The sum of each raw material component parts by weight are 100 parts.

Wherein, steel mill's grain slag refers to blast furnace slag under high temperature fused state, by being become with water rapid cooling Granulation foam shape slag charge；It is creamy white, light and crisp, porous, easily wear into fine powder.It is mainly by following weight percent The group of ratio is grouped as: SiO₂25~30%, Al₂O₃26~30%, Fe₂O₃0.5~1.5%, TiO₂0.1~0.7%, CaO 22~25%, MgO 8~9%, K₂O 0.1~0.5%, Na₂O0.2~1%, MnO₂2~4%, SO₃1~2, Cr₂O₃ 1.5 ~3%.It is ionizable as ionic crystals at high temperature containing 26~30% aluminium oxide in steel mill's grain slag of the invention, and It is combined with CaO in grain slag (content is 22~25%), forms calcium aluminate crystal, quality is extremely hard, helps to promote foamed ceramic Compression strength so that compression strength reaches 8MPa or more.Meanwhile steel mill's grain slag sheet is as cellular clinker, and containing 2~ 5% MnO₂, the two synthesis can reduce the thermal coefficient of foamed ceramic, so that thermal coefficient≤0.07W/mK.

Wherein, the red tailing in Luoyuan is remaining leftover pieces and some sawdusts etc. in the red process in Luoyuan, main It consists of the following components in percentage by weight: SiO₂68~73%, Al₂O₃12~15%, Fe₂O₃1.2~2%, CaO 0.5~ 1.5%, MgO 0.2~0.5%, K₂O 4~5.5%, Na₂O 3~5%, LOI 0.5~3%.The red tail in Luoyuan in the present invention Al in mine₂O₃Accounting is 12~15wt%, Al₂O₃It is mainly derived from feldspar and mica；Mica can be by among high temperature firing process Step is converted into mullite, provides intensity for high compressive strength foamed ceramic；Spectra can promote the crystallization of mullite to convert, Promote intensity.

Steel mill's grain slag in the present invention, the red tailings in Luoyuan are ridge raw material；And accounting is larger, so that in granulation process Biggish particle can not be formed, granularity required for the present invention is obtained.For this purpose, the present invention also added 3~10 in formula Part clay and 0.1~3 part of binder.

Specifically, the clay selects one of Luoyuan sand hill soil, mud washing, black mud, harbour road mud or ooze or a variety of.

Wherein, sand hill soil in Luoyuan refers to the sandy soil on the red mine surface layer in Luoyuan, mainly by following components in percentage by weight group At: SiO₂70~75%, Al₂O₃12~16%, Fe₂O₃0.5~1.5%, CaO 0.3~0.5%, MgO0.01~0.1%, K₂O 4~6%, Na₂O 3~5%, LOI 1~5%；Clay pit phase and the content of feldspar ore phase are higher in the sand hill soil of Luoyuan, Certain plasticity can be provided, firing temperature can be also further decreased.

Wherein, mud washing is the useless mud that sand hill soil in Luoyuan is washed, and average grain diameter is minimum (1 μm of D50 <)；Plasticity pole By force.The mud washing mainly consists of the following components in percentage by weight: SiO₂45~50%, Al₂O₃32~36%, Fe₂O₃ 2 ~3%, CaO 0.01~0.1%, MgO 0.3~0.5%, K₂O 2~3%, Na₂O0.3~0.8%, LOI 8~12%；Water It washes alumina content in mud and is up to 32~36%, mullite can be converted into during high temperature firing, it is strong to promote foamed ceramic Degree.

Wherein, the black mud mainly consists of the following components in percentage by weight: SiO₂61~65%, Al₂O₃20~ 24%, Fe₂O₃1.5~3%, CaO 0.3~1%, MgO 0.3~0.5%, K₂O 1~2%, Na₂O 0.2~0.6%, LOI 5~10%.

Wherein, harbour road mud refers to the mud between Luoyuan bay and river；It is mainly by following components in percentage by weight Composition: SiO₂68~72%, Al₂O₃12~15%, Fe₂O₃2~3%, CaO 3~5%, MgO 1.5~3%, K₂O 3.5 ~5%, Na₂O 1.5~3.5%, LOI 1~8%.The average grain diameter of this harbour road mud is small (1 μm of D50 <), and plasticity is good.

Wherein, ooze is the ooze in Luoyuan bay；It is mainly consisted of the following components in percentage by weight: SiO₂68~ 72%, Al₂O₃11~14%, Fe₂O₃3~4%, CaO 2~3.5%, MgO 1.5~2.5%, K₂O 3~5%, Na₂O 1 ~3%, LOI 3~10%.The average grain diameter of this ooze is small (1 μm of D50 <), and plasticity is good.

Preferably, in the present invention, the clay selects one of black mud, mud washing, harbour road mud or ooze or a variety of. It is further preferred that the clay in the present invention selects the mixture of mud washing and ooze, mud washing, the plasticity of ooze are relatively strong, And its Al₂O₃Content is relatively high, can form mullite crystal at high temperature, promotes the compression strength of foamed ceramic.

Specifically, in the present invention, the binder is selected sodium carboxymethylcellulose pyce, sodium carboxymethylcellulose, waterglass, is gathered One of acrylamide is a variety of.The introducing of binder can advanced optimize granulation performance.

Further, in order to reduce the thermal coefficient of foamed ceramic in the present invention, also containing foaming in formula of the invention 0~5 part of agent；The foaming agent is selected in silicon carbide, carbon dust or ceramic abrading block reclaimed materials (main component is silicon carbide and resin) It is one or more；Preferably, silicon carbide is selected.Foaming agent can decompose generation gas among high temperature firing process, with steel mill Grain slag matches, and the thermal coefficient of foamed ceramic is greatly lowered.Preferably, the addition parts by weight of foaming agent are 0.5~3 part.

Under the synergistic effect of above-mentioned formula and preparation method, the foamed ceramic that the present invention obtains, compression strength >= 10MPa, bulk density are 150~200kg/m³, water absorption rate≤0.5%, thermal coefficient≤0.08W/mK.

With specific embodiment, invention is further explained below: