阅读说明：本技术 一种硅酸镁陶质材料及其制备方法 (Magnesium silicate ceramic material and preparation method thereof ) 是由 孙红娟 唐颂 彭同江 罗利明 王璨 于 2021-09-26 设计创作，主要内容包括：本发明提供了一种硅酸镁陶质材料及其制备方法。制备方法包括：将含蛇纹石矿物的原料进行干燥和破碎,得到第一粉体；或者,将含蛇纹石矿物的原料进行干燥和破碎,得到第一粉体,再将第一粉体进行焙烧,得到第二粉体；将第一粉体和/或第二粉体与配料进行混合,获得混合物料粉体；将混合物料粉体进行造粒,获得球形颗粒状坯体；将球形颗粒状坯体进行干燥和烧结,获得硅酸镁陶质材料。硅酸镁陶质材料包括硅酸镁陶粒和/或硅酸镁陶砂,硅酸镁陶粒的直径为5mm～30mm,硅酸镁陶砂的直径为150μm～5mm。本发明以主要含蛇纹石的岩石、废石、尾矿为原料生产硅酸镁陶质材料,实现了多种固体废物的资源化利用。(The invention provides a magnesium silicate ceramic material and a preparation method thereof. The preparation method comprises the following steps: drying and crushing a raw material containing a serpentine mineral to obtain first powder; or drying and crushing the raw material containing the serpentine mineral to obtain first powder, and roasting the first powder to obtain second powder; mixing the first powder and/or the second powder with ingredients to obtain mixed material powder; granulating the mixed material powder to obtain a spherical granular blank; and drying and sintering the spherical granular blank to obtain the magnesium silicate ceramic material. The magnesium silicate ceramic material comprises magnesium silicate ceramic particles and/or magnesium silicate ceramic sand, the diameter of the magnesium silicate ceramic particles is 5-30 mm, and the diameter of the magnesium silicate ceramic sand is 150 mu m-5 mm. The invention takes the rocks, waste rocks and tailings mainly containing serpentine as raw materials to produce the magnesium silicate ceramic material, thereby realizing the resource utilization of various solid wastes.)

1. The preparation method of the magnesium silicate ceramic material is characterized by comprising the following steps of:

drying and crushing a raw material containing a serpentine mineral to obtain first powder; or drying and crushing the raw material containing the serpentine mineral to obtain first powder, and roasting the first powder to obtain second powder;

mixing the first powder and/or the second powder with ingredients to obtain mixed material powder;

granulating the mixed material powder to obtain a spherical granular blank;

drying and sintering the spherical granular blank to obtain the magnesium silicate ceramic material;

the ingredients comprise one or more of carbide slag powder, fly ash powder, yellow sand powder, silica slag powder, feldspar beneficiation tailing powder, nepheline beneficiation tailing powder, illite clay waste slag powder, bentonite waste slag powder and waste glass powder.

2. The method of producing a magnesium silicate ceramic material according to claim 1, wherein the serpentine mineral-containing raw material comprises one or more of serpentine, serpentine mill tailings, and chrysotile mill tailings.

3. The method for preparing a magnesium silicate ceramic material according to claim 1, wherein the first powder comprises, by mass, 25-40: 35-40: 2-10: 2-15: 2 to 5 of MgO and SiO₂、CaO、Fe₂O₃And Al₂O₃The particle diameter of the first powder is less than 150 mu m.

4. The method of claim 1, wherein the calcination step is carried out at 650-1200 ℃ for 2-90 min in one of a vertical kiln, a rotary kiln or a pre-decomposition kiln, and the second powder has an olivine as a main crystal phase.

5. The method of producing a magnesium silicate ceramic material according to claim 1, wherein the particle size of the ingredients is 75 μm or less.

6. The method of preparing a magnesium silicate ceramic material according to claim 1, wherein the mixing the first powder and/or the second powder with the ingredients comprises:

under the condition that the first powder is mixed with the ingredients, the adding amount of the ingredients is 20-40% of the mass of the first powder; or

Under the condition that the second powder is mixed with the ingredients, the adding amount of the ingredients is 15-30% of the mass of the second powder; or

Under the condition that the first powder, the second powder and the ingredients are mixed, the mass ratio of the first powder to the second powder to the ingredients is 40-80: 10-40: 10 to 40.

7. The method of producing a magnesium silicate ceramic material according to claim 1, wherein the granulation step is wet granulation, and comprises: rotating the mixed material powder at the rotating speed of 30-70 r/min for 5-20 min, then adding water and a binder, and continuing to rotate and granulate for 30-90 min, wherein,

the adding amount of the water is 8-16% of the mass of the mixed material powder, and the adding amount of the binder is 4-20% of the mass of the mixed material powder.

8. The method of producing a magnesium silicate ceramic material as claimed in claim 1, wherein said process of drying the spherical granular green body comprises: drying the spherical granular blank at the temperature of 60-110 ℃ for 30-90 min; the sintering link is sintering for 3-120 min at 800-1250 ℃.

9. A magnesium silicate ceramic material, characterized in that it is produced by the production method according to any one of claims 1 to 8.

10. The magnesium silicate ceramic material according to claim 9, wherein the bulk density of the magnesium silicate ceramic material is 300 to 1100kg/m³The heat conductivity coefficient is less than or equal to 0.14W/(m.k), the compressive strength is more than or equal to 0.5MPa, and the water absorption rate is 2-15%; the magnesium silicate ceramic material comprises magnesium silicate ceramic particles and/or magnesium silicate ceramic sand, the diameter of the magnesium silicate ceramic particles is 5-30 mm, and the diameter of the magnesium silicate ceramic sand is 150 mu m-5 mm.

Technical Field

The invention belongs to the technical field of resource utilization of waste ore and waste residue and the technical field of materials, and particularly relates to a preparation method for preparing a magnesium silicate ceramic material by using a raw material containing serpentine minerals as a raw material, and a magnesium silicate ceramic material product.

Background

China is a large country with serpentine mine resources, and the proven reserves exceed 5 hundred million tons. The serpentine generates a large amount of crushed ores in the mining process, and tailings with the granularity of 2-3 cm account for 1/3-1/2 of the mined ores. According to statistics, the amount of the discarded fine ore is up to 10 ten thousand tons every year. The fine ores are rich in magnesium oxide, silicon dioxide, iron oxide and calcium oxide, and are valuable mineral resources. However, an effective utilization way is still lacked so far, and a plurality of mining areas mainly use stockpiling, so that potential pollution is brought to the environment while a large amount of precious land resources are occupied.

On the other hand, the ceramsite has the characteristics of light weight, high strength and the like, is widely applied in various domestic fields, can replace increasingly scarce natural building materials such as sandstone and the like in the building field for producing concrete, and the ceramic sand with the particle size of less than 5mm obtained after screening has good chemical and thermal stability, can be used for replacing natural river sand to produce light concrete, light mortar and the like, is a high-quality natural sandstone replacement resource, and is in short supply in the building field.

Disclosure of Invention

The present invention aims to address at least one of the above-mentioned deficiencies of the prior art. For example, one of the purposes of the invention is to provide a method for preparing a magnesium silicate ceramic material which takes serpentine-containing rocks, waste rocks and tailings as raw materials, has the advantages of simple preparation method, energy conservation and emission reduction, high added value of products and high ecological environmental benefit. For another example, another object of the present invention is to provide a magnesium silicate ceramic material with excellent properties of low density, light weight, porosity, strong water absorption, good thermal insulation, high strength, fire resistance, flame retardancy, etc., wherein the magnesium silicate ceramic material comprises magnesium silicate ceramic particles and/or magnesium silicate ceramic sand.

In order to achieve the above objects, an aspect of the present invention provides a method for preparing a magnesium silicate ceramic material, comprising the steps of: drying and crushing a raw material containing a serpentine mineral to obtain first powder; or drying and crushing the raw material containing the serpentine mineral to obtain first powder, and roasting the first powder to obtain second powder; mixing the first powder and/or the second powder with ingredients to obtain mixed material powder; granulating the mixed material powder to obtain a spherical granular blank; drying and sintering the spherical granular blank to obtain the magnesium silicate ceramic material; the ingredients comprise one or more of carbide slag powder, fly ash powder, yellow sand powder, silica slag powder, feldspar beneficiation tailing powder, nepheline beneficiation tailing powder, illite clay waste slag powder, bentonite waste slag powder and waste glass powder.

In an exemplary embodiment of the invention, the serpentine mineral-containing feedstock may include one or more of serpentine, serpentine mill tailings, and chrysotile mill tailings.

In an exemplary embodiment of the invention, the first powder may include 25 to 40 mass ratio: 35-40: 2-10: 2-15: 2 to 5 of MgO and SiO₂、CaO、Fe₂O₃And Al₂O₃The particle size of the first powder may be 150 μm or less, for example, the particle size of the first powder is 10 to 150 μm.

In an exemplary embodiment of the present invention, the firing process may be firing at 650 to 1200 ℃ for 2 to 90 min; for example, the material can be baked at 950 to 1150 ℃ for 12 to 25 min. The roasting is carried out in one of a vertical kiln, a rotary kiln or a pre-decomposition kiln, and the main crystal phase of the second powder can be olivine.

In an exemplary embodiment of the invention, the particle size of the ingredients may be 75 μm or less, for example, the particle size of the ingredients is 2, 3, 4, 10, 20, 30, 40, 50, 60, 70, 71, 74, 75 μm.

In an exemplary embodiment of the invention, the formulation may include one or more of carbide slag powder, silica slag powder, feldspar mill tailings powder, nepheline mill tailings powder, illite clay waste slag powder, bentonite waste slag powder, and waste glass powder, such as, for example, carbide slag powder and/or silica slag powder, such as, for example, feldspar mill tailings powder and/or nepheline mill tailings powder, such as, for example, illite clay waste slag powder, bentonite waste slag powder, and waste glass powder, and the like.

In an exemplary embodiment of the present invention, the mixing the first powder and/or the second powder with the ingredients may include:

under the condition that the first powder is mixed with the ingredients, the adding amount of the ingredients is 20-40% of the mass of the first powder; furthermore, the addition amount of the ingredients is 20-40% of the mass of the first powder, such as 21%, 25%, 26%, 30%, 35%, 38% and the like.

Or under the condition that the second powder is mixed with the ingredients, the adding amount of the ingredients is 15-30% of the mass of the second powder.

Or under the condition that the first powder, the second powder and the ingredients are mixed, the mass ratio of the first powder, the second powder and the ingredients is 40-80: 10-40: 10-40; further, the mass ratio of the first powder to the second powder to the ingredients is 45-75: 12-38: 12 to 29.

In an exemplary embodiment of the present invention, the granulation process may be wet granulation, and may include: rotating the mixed material powder for 5-20 min at the rotating speed of 30-70 r/min, then adding water and a binder, and then continuing to perform rotary granulation for 30-90 min, wherein the adding amount of the water is 8-16% of the mass of the mixed material powder, and the adding amount of the binder is 4-20% of the mass of the mixed material powder.

In an exemplary embodiment of the present invention, the process of drying the spherical granular blank may be: drying the spherical granular blank at the temperature of 60-110 ℃ for 30-90 min; the sintering link can be sintering at 800-1250 ℃ for 3-120 min.

According to another aspect of the invention, the magnesium silicate ceramic material is prepared by any one of the preparation methods.

In an exemplary embodiment of the inventionIn an embodiment, the magnesium silicate ceramic material has a bulk density of 300-1100 kg/m³The heat conductivity coefficient is less than or equal to 0.14W/(m.k), the compressive strength is more than or equal to 0.5MPa, and the water absorption rate is 2-15%; the magnesium silicate ceramic material can comprise magnesium silicate ceramic particles and/or magnesium silicate ceramic sand, the diameter of the magnesium silicate ceramic particles is 5-30 mm, and the diameter of the magnesium silicate ceramic sand is 150 mu m-5 mm.

Compared with the prior art, the beneficial effects of the invention can comprise at least one of the following:

(1) the product takes rocks, waste rocks and tailings mainly containing serpentine as raw materials to produce the magnesium silicate ceramic material, a small amount of ingredients are added, the main ingredients are mostly solid wastes, and after resource utilization, the product has important ecological and sustainable development significance for resource protection, saving, high-value utilization and ecological environment protection;

(2) the recycling of the tailings, the waste rocks and the tailings has important ecological and environmental significance on the safety, environmental protection, reclamation and greenness of the tailings pond;

(3) the preparation method for obtaining the novel magnesium silicate ceramic material by processing and treating the rocks, waste rocks and tailings mainly containing serpentine as raw materials has the advantages of simple and convenient production process, energy conservation and emission reduction, high product added value, high ecological environmental benefit and the like, and has important significance for developing new material industry and social economy;

(4) asbestos fibers in rocks, waste rocks and tailings are decomposed and transformed into non-toxic and harmless olivine and pyroxene through roasting treatment and sintering treatment, so that the detoxification treatment of the asbestos fibers is realized;

(5) the prepared magnesium silicate ceramic material can comprise magnesium silicate ceramic particles and/or magnesium silicate ceramic sand, has the excellent properties of small density, light weight, porosity, strong water absorption, good heat preservation performance, high strength, fire resistance, flame retardance and the like, and has wide application in the aspects of building materials, flower cultivation, soil improvement, adsorbing materials, filtering materials and the like.

Drawings

Figure 1 shows a flow chart of a method of preparation of an exemplary embodiment 1 of the method of the present invention.

Detailed Description

Hereinafter, the magnesium silicate ceramic material and the method for preparing the same according to the present invention will be described in detail with reference to exemplary embodiments.

Exemplary embodiment 1

As shown in fig. 1, in the present exemplary embodiment, the preparation method of the magnesium silicate ceramic material may be implemented by the following steps:

s1, obtaining the first powder and/or the second powder

In this example, the raw material containing the serpentine mineral was dried and crushed to obtain the first powder. Here, the serpentine mineral-containing raw material may include one or more of serpentine, serpentine mill tailings and chrysotile mill tailings, and the serpentine mineral-containing raw material is mainly a layered silicate mineral, and generally does not contain sulfate and halogen compound minerals.

The drying process can be carried out in a dryer, parameters such as the temperature and the time of the dryer are adjusted, so that the moisture content of the dried raw material containing the serpentine mineral is less than or equal to 5 percent, such as 1.0 percent, 1.5 percent, 3.5 percent, 4.5 percent and the like, the obtained powder is prevented from agglomerating while the crushing rate is ensured, and the agglomeration is easy when the moisture content exceeds 5 percent. The drying temperature of the dryer can be 60-150 ℃, such as 80, 100, 140 ℃ and the like, and the drying time is 30-150 min, such as 40, 60, 80, 120min and the like.

The crushing process can be carried out by adopting a closed crushing mode, so that the crushing efficiency is improved, and the uniform granularity can be ensured. The crushing process can be carried out in a closed workshop, so that the method is environment-friendly and can prevent the serpentine fiber from diffusing into the environment to cause adverse effects.

The moisture content (free water) of the obtained first powder is below 5%, the moisture content is controlled within the range, the implementation of subsequent processes is facilitated, and when the moisture content is higher than 5%, excessive energy is consumed in the roasting process, cracks are easy to generate, and the roasting quality is reduced.

The first powder obtained here comprises, by mass, 25 to 40 (for example, 26, 30, 35, 39): 35-40 (e.g., 36, 37, 38, 39): 2-10 (e.g., 3, 5, 7, 8, 9): 2-15 (e.g., 3, 5, 10, 14): 2 to 5 (e.g., 3, 4, 5) of MgO and SiO₂、CaO、Fe₂O₃And Al₂O₃. In addition, the particle size of the first powder is 150 μm or less, for example, the particle size of the first powder is 10 to 150 μm, and when the particle size of the first powder is less than 10 μm, the specific surface area of the powder is too large, the surface energy is high, the powder is easily agglomerated, and excessive energy is consumed in the production process, which is uneconomical; when the particle size of the first powder exceeds 150 microns, the uniformity of subsequent products can be influenced, so that the proper particle size range of the first powder can be 10 microns-150 microns, a certain fineness can be ensured, and later-stage granulation is facilitated; and powder agglomeration caused by over-fineness can be avoided, and later granulation is influenced.

In this embodiment, the serpentine mineral-containing raw material may be dried and crushed to obtain a first powder, and then the first powder may be calcined to obtain a second powder. That is, the first powder and the second powder can be obtained simultaneously or only the second powder can be obtained. The main crystal phase of the obtained second powder is olivine, the obtained second powder has no structural water compared with the first powder, and serpentine mineral with the main crystal phase of asbestos phase is converted into olivine by roasting, so that the serpentine mineral is subjected to phase inversion and detoxification.

The drying and crushing processes are the same as above, and are not described in further detail herein.

The roasting process can be carried out for 2 min-90 min at 650-1200 ℃, the heating rate is 10-30 ℃/min, and the first powder can be placed in one of a vertical kiln, a rotary kiln or a precalcination kiln for roasting. The calcination temperature is too low (such as lower than 650 ℃), asbestos phase in the serpentine mineral is not completely transformed into olivine, the phase-transformation detoxification effect cannot be achieved, and the calcination temperature is too high (such as higher than 1200 ℃), so that over-sintering occurs, partial phases are fused, the particle density after sintering is large, the quality of subsequent products is reduced, and the energy consumption is increased. The roasting time is too short to achieve the roasting effect, the roasting time is too long, the energy consumption is increased, and the product economy is reduced.

S2, mixing with the ingredients to obtain mixed material powder

Specifically, the first powder obtained in step S1 may be mixed with ingredients to obtain a mixed material powder, where the amount of the ingredients added is 20 to 40% of the mass of the first powder; or mixing the second powder obtained in the step S1 with ingredients to obtain a mixed material powder, wherein the amount of the ingredients added is 15-30% of the mass of the second powder; the first powder and the second powder obtained in the step S1 may be mixed with the ingredients, and the mass ratio of the first powder to the ingredients may be 40 to 80 (for example, 41, 50, 55, 60, 70, 79): 10-40 (e.g., 11, 15, 20, 23, 30, 36, 39): 10-40 (e.g., 11, 14, 20, 23, 30, 36, 39). The addition amount of the ingredients is selected within the range, so that the obtained product has low density and high strength, and meets the corresponding product quality requirement.

In other words, the invention has three batching modes, the first batching mode is as follows: only the first powder is obtained, and the first powder is mixed with the ingredients; the second material preparation mode is as follows: only the second powder is obtained, and the second powder is mixed with the ingredients; the third material preparation method comprises the following steps: obtaining first powder and second powder, and mixing the first powder, the second powder and ingredients. The final products obtained by the three burdening modes are the same, and the difference lies in that the technological processes of different burdening modes are different: the first batching mode omits roasting of the first powder, and actually roasting of the first powder is carried out after granulation, so that the advantage of the roasting process of the first powder is omitted, but because phase inversion detoxification is not carried out, dust has certain adverse effect on the environment in the mixing process of the first powder and the batching; the second material mixing mode reduces the adverse effect of the first mode, but increases the roasting process; and the third material mixing mode increases the preparation flexibility, can be applied to the first powder (raw material) obtained by roasting and the second powder (clinker) obtained by roasting, and has more flexible process.

Here, the ingredients may include one or more of carbide slag powder, fly ash powder, yellow sand powder, silica slag powder, feldspar mill tailing powder, nepheline mill tailing powder, illite clay waste slag powder, bentonite waste slag powder, and waste glass powder. The ingredients are mainly solid waste materials rich in silicon or silicon and magnesium, so that the content of magnesium silicate in the ceramic material can be increased, and in addition, the particle size of the ingredients can be below 75 micrometers, for example, the particle size of the ingredients is 5-75 micrometers, and for example, the particle size of the ingredients is 45-70 micrometers.

S3, granulating to obtain spherical granular blank

Specifically, the mixed material powder obtained in step S2 is granulated and shaped by a granulating and shaping machine to obtain a spherical granular green body, and the shaping is performed to increase the roundness and sphericity of the granules and to make the granules smooth and round.

The granulation process can be wet granulation, the mixed material powder is placed in a granulator and rotated for 5-20 min at the rotating speed of 30-70 r/min, then water and a binder are added, and the granulation is continued for 30-90 min in a rotating mode, wherein the adding amount of the water is 10-15% of the mass of the mixed material powder, and the adding amount of the binder is 4-20% of the mass of the mixed material powder. For example, the binder may be a 3-10% concentration aqueous solution of polyvinyl alcohol, the water is industrial water, and for example, the binder may be other commonly used reagents in the field, which are not described herein in detail, and after granulation is finished, the granules are shaped on a spherical shaping machine for 5-30 min, so that spherical granular blanks with better sphericity and roundness are obtained.

S4, obtaining the magnesium silicate ceramic material

Specifically, the spherical granular green body obtained in the above step S4 is dried and sintered to obtain a magnesium silicate ceramic material. Here, the main phase composition of the magnesium silicate ceramic material is olivine, pyroxene, quartz, and magnetite. The magnesium silicate ceramic material can comprise magnesium silicate ceramic particles and/or magnesium silicate ceramic sand, for example, the volume density of the prepared magnesium silicate ceramic material can be 300-1100 kg/m³The heat conductivity coefficient is less than or equal to 0.14W/(m.k), the compressive strength is greater than or equal to 0.5MPa, the water absorption is 2-15%, the diameter of the magnesium silicate ceramic material can be 150 mu m-30 mm, the diameter of the magnesium silicate ceramic particle is 5 mu m-30 mm, and the diameter of the magnesium silicate ceramic sand is 150 mu m-5 mm.

The drying process may be drying at 60-110 deg.C for 30-90 min, such as drying at 60-80 deg.C for 60-90 min, or drying at 100-110 deg.C for 30-40 min. The drying process may also be performed in a kiln used for sintering to optimize the process and increase efficiency. For example, the drying and sintering may be performed in a shaft kiln, a roller kiln or a rotary kiln, or, for example, the drying and sintering may be performed in other apparatuses commonly used in the art, which will not be described in detail herein. Here, the tail gas in the roasting step in the step S1 may be cooled to 105 ℃, and then the spherical granular green body may be dried for 30-40 min.

The sintering step can comprise: sintering at 800-1250 ℃ for 3-120 min. For example, the sintering temperature may be 810, 830, 850, 900, 920, 960, 980, 1000, 1040, 1050, 1060, 1090, 1110, 1160, 1180, 1190, 1210, 1230, 1240 ℃, etc.; for example, the sintering time may be 5, 6, 10, 24, 50, 70, 80, 90, 100, 110, 114, 115min, and the like. Wherein the heating rate of heating to the sintering temperature can be 10-30 ℃/h, so as to obtain the magnesium silicate ceramic material; for example, the ramp rate may be 11, 15, 19, 21, 25, 27, 29 min/deg.C. In the temperature range, a better sintering effect can be achieved, so that the magnesium silicate ceramic material product obtained after sintering has high strength and low density, when the temperature is lower than 750 ℃, the strength of the sintered product is low and is difficult to reach the high strength standard, and is higher than 1200 ℃, energy is easily consumed, the density of the sintered product is increased, the product performance and the use quality are reduced, so that the optimal sintering temperature range exists, the sintering time is also the same, the time is too low, the sintering effect cannot be achieved, the time is too long, the over-sintering is easily caused while the energy is consumed, the product density is increased, and the optimal effect cannot be achieved. For the temperature rising speed, if the temperature rising rate is too high, the particles are heated unevenly and are easy to crack in the sintering process, and if the temperature rising speed is too low, the working procedure is too long in time, and the production efficiency is affected.

In addition, in this embodiment, after the magnesium silicate ceramic material is obtained in step S4, a post-treatment may be performed, that is, the magnesium silicate ceramic material is sieved to obtain magnesium silicate ceramic particles and magnesium silicate ceramic sand with different diameters, and the sieving method may be performed by using a vibrating sieve.

Exemplary embodiment 2

In the present exemplary embodiment, the method for preparing the magnesium silicate ceramic material may include the steps of:

1) drying the raw material containing the serpentine mineral, and crushing the dried raw material in a closed-circuit crushing mode to obtain first powder, wherein the first powder comprises the following components in percentage by mass: 25-40% MgO, 35-40% SiO₂、2～10％CaO、2～15％Fe₂O₃And 2-5% Al₂O₃And the grain diameter of the first powder is not less than 10 μm and not more than 150 μm.

The obtained first powder can be placed in a vertical kiln, a rotary kiln or a pre-decomposition kiln to be roasted for 2min to 90min at the temperature of 650 ℃ to 1200 ℃ to obtain second powder of which the main crystal phase is olivine.

2) And mixing the first powder and/or the second powder with ingredients to obtain mixed material powder, wherein the ingredients can comprise one or more of carbide slag powder, fly ash powder, yellow sand powder, silica slag powder, feldspar ore dressing tailing powder, nepheline ore dressing tailing powder, illite clay waste slag powder, bentonite waste slag powder and waste glass powder. The first powder and ingredients can be mixed, and the adding amount of the ingredients is 20-40% of the mass of the first powder; or mixing the second powder with ingredients, wherein the adding amount of the ingredients is 15-30% of the mass of the second powder; the powder mixing method also comprises the following steps of mixing a first powder, a second powder and ingredients, wherein the mass ratio of the first powder to the second powder to the ingredients is (40-80): 10-40: 10 to 40.

3) And uniformly mixing the mixed material powder, putting the mixed material powder into a granulator, wherein the rotating speed of the granulator can be 30-70 r/min, then adding the binder and water, and continuously rotating the granulator for 30-90 min. So as to obtain the spherical granular blank.

4) And drying the spherical granular blank at 105 ℃ for not less than 4 hours until the weight is constant, and sintering at 800-1250 ℃ for 40-120 min to obtain the magnesium silicate ceramic material. After the magnesium silicate ceramic material is screened, the magnesium silicate ceramic particles and/or the magnesium silicate ceramic sand can be respectively obtained. The drying and sintering can be carried out in a shaft kiln, a roller kiln or a rotary kiln, but the drying procedure and the sintering procedure can be carried out in the same kiln.

The technical solution of the present invention is further explained by detailed examples below.

Example 1

The specific preparation method of this example is as follows:

(1) placing the serpentine in a dryer 60℃Drying for 90min, and crushing in a closed crushing mode to obtain first powder with water content of 4%. The first powder comprises 30% of MgO and 38% of SiO₂10% of CaO, 8% of Fe₂O₃And 4% of Al₂O₃And the balance being unavoidable substances. The first powder has a particle size of 50 to 100 μm.

And then placing the first powder in a pre-decomposition kiln from room temperature to 1200 ℃, and roasting at 1200 ℃ for 10min to obtain second powder with the main crystal phase of olivine. Wherein the temperature rise rate is 15 ℃/h.

(2) Mixing the first powder, the fly ash powder and the yellow sand powder according to a mass ratio of 60: 15: 25, and uniformly mixing in a dry powder mixer for 30min to obtain mixed material powder. Wherein the particle size of the quicklime powder and the fly ash powder is 45-75 mu m.

(3) And granulating the mixed material powder by adopting a wet method, rotating the mixed material powder for 20min at the rotating speed of 40r/min, adding 12% of water and 8% of binder, continuously rotating and granulating for 80min, and shaping for 10min by using a granulating and shaping machine to obtain a spherical granular blank.

(4) And (2) cooling the hot tail gas generated by the precalcining kiln in the step (1) to 105 ℃, introducing the cooled hot tail gas into a vertical kiln, drying the spherical granular blank for 30min, heating the spherical granular blank to 1150 ℃ at a rate of 25 ℃/min, and sintering the spherical granular blank for 10min to obtain a product A.

The bulk density of the product A is 500-1100 kg/m³The thermal conductivity coefficient is 0.12W/(m.k), the compressive strength is 0.8MPa, and the water absorption is 10%. The particle size of the product A is between 150 mu m and 20mm, and after the product A is screened by a vibrating screen, magnesium silicate ceramsite with the particle size between 5mm and 20mm and magnesium silicate ceramic sand with the particle size between 150 mu m and 5mm are obtained.

Example 2

The specific preparation method of this example is as follows:

(1) drying serpentine beneficiation tailings in a dryer, crushing in a closed crushing mode, and drying at 70 ℃ for 120min to obtain first powder with the water content of 3%. The first powder comprises 38% of MgO and 32% of SiO₂5% of CaO, 10% of Fe₂O₃And 5% of Al₂O₃The balance being unavoidable materials; the first powder has a particle size of 10 to 100 μm.

And then placing the first powder in a rotary kiln, raising the temperature from room temperature to 750 ℃ at a heating rate of 10 ℃/min, and keeping the temperature for 60min for roasting to obtain second powder of which the main crystal phase is olivine.

(2) The second powder, illite clay waste residue powder and bentonite waste residue powder are mixed according to the mass ratio of 80: 10: 10, and uniformly mixing in a dry powder mixer for 30min to obtain mixed material powder. Wherein the particle size of the illite clay waste residue powder and the bentonite waste residue powder is 45-75 mu m.

(3) And granulating the mixed material powder by adopting a wet method, rotating the mixed material powder in a granulator for 15min at the rotating speed of 60r/min, adding 15% of water and 15% of binder, continuing to operate for 70min, and shaping for 15min by using a shaping machine to obtain a spherical granular blank.

(4) And (2) cooling the hot tail gas generated by the rotary kiln in the step (1) to 105 ℃, introducing the hot tail gas into a vertical kiln, drying the spherical granular blank for 30min, heating the spherical granular blank to 1050 ℃ at a speed of 10 ℃/h, and sintering the spherical granular blank for 30min to obtain a product B.

The bulk density of the product B is 300-800 kg/m³The product B is magnesium silicate ceramsite with the thermal conductivity coefficient of 0.10W/(m.k), the compressive strength of 0.6MPa, the water absorption of 12 percent and the diameter of 10-20 mm.

Example 3

The specific preparation method of this example is as follows:

(1) putting the chrysotile mill tailings into a dryer, drying at 130 ℃ for 40min, and crushing in a closed crushing mode to obtain first powder with the water content of 1%. The first powder comprises 35% of MgO and 38% of SiO₂2% of CaO, 12% of Fe₂O₃And 5% of Al₂O₃The particle size of the first powder is 10-150 μm.

And then the first powder is put into a vertical kiln and heated to 850 ℃ at the speed of 5 ℃/min, and is roasted for 30min, so that second powder with the main crystal phase of olivine is obtained.

(2) Mixing the first powder, the second powder, the carbide slag powder and the waste glass powder according to a mass ratio of 60: 15: 10: 15, and uniformly mixing in a dry powder mixer for 30min to obtain mixed material powder. Wherein the particle size of the carbide slag powder and the waste glass powder is 45-75 mu m.

(3) And granulating the mixed material powder by adopting a wet method, rotating the mixed material powder in a granulator for 18min at a rotating speed of 50r/min, adding 10% of water and 10% of a binder, continuing to operate for 60min, and shaping for 20min by using a shaping machine to obtain a spherical granular blank. (4) And (2) cooling the hot tail gas generated by the rotary kiln in the step (1) to 105 ℃, introducing the hot tail gas into a vertical kiln, drying the spherical granular blank for 35min, heating the temperature to 900 ℃ at a speed of 15 ℃/h, and sintering the blank for 90min to obtain a product C.

The bulk density of the product C is 800-1100 kg/m³The product C has a particle size of 150-2000 mu m and is made of magnesium silicate ceramic sand, the thermal conductivity is 0.10W/(m.k), the compressive strength is 1.0MPa, the water absorption is 2%, and the particle size of the product C is between 150 and 2000 mu m.

Example 4

The specific preparation method of this example is as follows:

(1) placing the serpentine mill tailings in a dryer, drying at 80 ℃ for 30min, and crushing in a closed crushing mode to obtain first powder with the water content of 2.5%. The obtained first powder comprises 34% of MgO and 36% of SiO₂5% of CaO, 7% of Fe₂O₃And 3% of Al₂O₃And the balance being unavoidable substances. The particle size of the first powder is 10-150 μm.

And then the first powder is put into a pre-decomposition kiln and heated to 1150 ℃ at the speed of 15 ℃/min, and is roasted for 10min, so that second powder with the main crystal phase of olivine is obtained.

(2) And (3) mixing the second powder and nepheline beneficiation tailing powder according to the mass ratio of 80: 20, and uniformly mixing in a dry powder mixer for 30min to obtain mixed material powder. Wherein the grain size of the nepheline beneficiation tailing powder is 45-75 μm. The second powder has a particle size of 10 to 150 μm.

(3) And granulating the mixed material powder by adopting a wet method, rotating the mixed material powder in a granulator for 5min at the rotating speed of 70r/min, adding 13% of water and 12% of binder, continuing to operate for 80min, and shaping for 15min by using a shaping machine to obtain a spherical granular blank.

(4) And (2) cooling the hot tail gas generated by the precalcining kiln in the step (1) to 105 ℃, introducing the cooled tail gas into a vertical kiln, drying the spherical granular blank for 25min, heating the dried spherical granular blank to 1100 ℃ at a speed of 10 ℃/h, and sintering the dried spherical granular blank for 25min to obtain a product D.

The bulk density of the product D is 600-1200 kg/m³The thermal conductivity coefficient is 0.12W/(m.k), the compressive strength is 0.8MPa, the water absorption is 6 percent, the particle size of the product D is between 150 mu m and 20mm, and after the product D is screened by a vibrating screen, the magnesium silicate ceramsite with the particle size between 5mm and 20mm and the magnesium silicate ceramic sand D with the particle size between 150 mu m and 5mm are obtained.

Example 5

The specific preparation method of this example is as follows:

(1) placing serpentine and chrysotile mill tailings in a dryer, drying at 70 ℃ for 40min, and crushing in a closed-circuit crushing mode to obtain first powder with the water content of 3%. The obtained first powder comprises 33% of MgO and 35% of SiO₂9% of CaO, 10% of Fe₂O₃And 4% of Al₂O₃The particle size of the first powder is 10-150 μm.

(2) Mixing the first powder and the silica slag powder according to a mass ratio of 70: 30, and uniformly mixing in a dry powder mixer for 40min to obtain mixed material powder. Wherein the particle size of the silica slag powder is 50 to 100 μm.

(3) And granulating the mixed material powder by adopting a wet method, rotating the mixed material powder in a granulator for 15min at a rotating speed of 50r/min, adding 9% of water and 10% of a binder, continuing to operate for 50min, and shaping for 10min by using a shaping machine to obtain a spherical granular blank.

(4) And (2) cooling the hot tail gas generated by the precalcining kiln in the step (1) to 105 ℃, introducing the cooled hot tail gas into a vertical kiln, drying the spherical granular blank for 30min, heating the dried spherical granular blank to 1050 ℃ at a speed of 20 ℃/h, and sintering the dried spherical granular blank for 40min to obtain a product E.

The bulk density of the product E is 400-1000 kg/m³The thermal conductivity coefficient is 0.1W/(m.k), the compressive strength is 0.9MPa, the water absorption is 4 percent, the particle size of the product E is between 150 mu m and 20mm, and after the product E is screened by a vibrating screen, the magnesium silicate ceramsite with the particle size between 5mm and 20mm and the magnesium silicate ceramic sand with the particle size between 150 mu m and 5mm are obtained.

In summary, the magnesium silicate ceramic material and the preparation method thereof of the present invention have at least one of the following beneficial effects:

1) rocks, waste rocks and tailings mainly containing serpentine are used as raw materials, and low-grade resources and solid waste residues are utilized;

2) the production process is simple and convenient, energy is saved, emission is reduced, the added value of the product is high, the ecological environment benefit is high, and the like, and the method has important significance for developing new material industry and social economy;

3) the recycling of the tailings, the waste rocks and the tailings has important ecological and environmental significance on the safety, environmental protection, reclamation and greenness of the tailings pond;

4) asbestos fibers in rocks, waste rocks and tailings are decomposed and transformed into non-toxic and harmless olivine and pyroxene through roasting treatment and sintering treatment, so that the detoxification treatment of the asbestos fibers is realized;

5) the magnesium silicate ceramic material prepared by the preparation method can comprise magnesium silicate ceramic particles and/or magnesium silicate ceramic sand, has the excellent properties of small density, light weight, porosity, strong water absorption, good heat preservation performance, high strength, fire resistance, flame retardance and the like, and has wide market prospect and remarkable economic, environmental and social benefits;

6) the magnesium silicate ceramic material has wide application in the aspects of building materials, flower cultivation, soil improvement, adsorption materials, filter materials and the like.

Although the present invention has been described above in connection with the exemplary embodiments and the accompanying drawings, it will be apparent to those of ordinary skill in the art that various modifications may be made to the above-described embodiments without departing from the spirit and scope of the claims.