阅读说明：本技术 利用锂辉石浮选尾矿低温烧结制备多孔陶瓷材料的方法 (Method for preparing porous ceramic material by utilizing spodumene flotation tailings through low-temperature sintering ) 是由 徐龙华 杨洁 巫侯琴 王周杰 于 2020-03-17 设计创作，主要内容包括：本发明提供了一种利用锂辉石浮选尾矿低温烧结制备多孔陶瓷材料的方法,包括以下步骤：(1)称取原料：锂辉石浮选尾矿65～75％、生坯粘结材料10～12％、高温粘结材料15-25％；向上述固体原料中加水混合搅拌得到浆料；(2)向步骤(1)所得浆料中加入过氧化氢溶液,过氧化氢的加入体积按占固体原料质量比为5～15ml/kg添加,搅拌均匀后通过常压注模成型,静置24h使其充分发泡；(3)将步骤(2)所得物进行脱模烘干,坯体在550～650℃下烧结制得多孔陶瓷材料。本发明方法成功在较低温度下烧结制备出了力学性能优异的高吸水率多孔陶质材料,所得材料气孔率高,最高达56.79％,吸水率高,最高达52.68％。(The invention provides a method for preparing a porous ceramic material by utilizing spodumene flotation tailings through low-temperature sintering, which comprises the following steps: (1) weighing the following raw materials: 65-75% of spodumene flotation tailings, 10-12% of green body bonding materials and 15-25% of high-temperature bonding materials; adding water into the solid raw materials, mixing and stirring to obtain slurry; (2) adding a hydrogen peroxide solution into the slurry obtained in the step (1), wherein the adding volume of the hydrogen peroxide is 5-15 ml/kg of the solid raw material by mass ratio, uniformly stirring, performing normal-pressure injection molding, and standing for 24 hours to fully foam; (3) and (3) demolding and drying the product obtained in the step (2), and sintering the blank at 550-650 ℃ to obtain the porous ceramic material. The method successfully prepares the high-water-absorption porous ceramic material with excellent mechanical properties by sintering at a lower temperature, and the obtained material has high porosity up to 56.79% and high water absorption up to 52.68%.)

1. A method for preparing a porous ceramic material by utilizing spodumene flotation tailings through low-temperature sintering is characterized by comprising the following steps:

(1) weighing the following raw materials in percentage by mass of total solids: 65-75% of spodumene flotation tailings, 10-12% of green body bonding materials and 15-25% of high-temperature bonding materials; adding water into the solid raw materials, mixing and stirring to be in a slurry state to obtain slurry; the green body bonding material is a mixture of sodium carboxymethylcellulose and kaolin, and the mass ratio of the green body bonding material to the kaolin is 1: 19, the high-temperature bonding material is a mixture of low-melting-point glass powder and borax, the mass ratio of the high-temperature bonding material to the borax is 5: 1-2, and the addition amount of water is 0.8 times of the weight of spodumene flotation tailings;

(2) adding a hydrogen peroxide solution with the mass percent of 30% into the slurry obtained in the step (1), adding the hydrogen peroxide solution according to the mass ratio of 5-15 ml/kg of the solid raw material, uniformly stirring, performing normal-pressure injection molding, and standing for 24 hours to fully foam;

(3) and (3) demolding and drying the product obtained in the step (2), and sintering the blank at 550-650 ℃ to obtain the porous ceramic material.

2. The method according to claim 1, wherein the spodumene flotation tailings are tailings obtained after lithium production enterprises extract lithium through a flotation process or tailings obtained after a leaching process.

3. The method according to claim 1, wherein the step of demolding and drying in step (3) is: drying at 60 deg.C for 48h in an electrothermal blowing drier, taking out, demolding, and drying at 120 deg.C for 24h to obtain the final product.

4. The method according to claim 1, wherein the sintering process of the green body in the step (3) is as follows: and (3) after the green body sample is cooled to room temperature, placing the green body sample in a high-temperature experimental furnace for normal-pressure sintering, heating to the sintering temperature at the speed of 8 ℃/min, preserving the heat for 1h, cooling to room temperature along with the furnace after sintering is finished, and taking out.

Technical Field

The invention belongs to the technical field of preparing ceramic materials from industrial solid wastes, and particularly relates to a method for preparing a high-water-absorption porous ceramic material by sintering spodumene flotation tailings at a low temperature.

Background

With the development of society, resource and environment problems are increasingly prominent, how to properly treat solid waste becomes a current hot problem, flotation tailings are used as special solid waste in the solid waste due to the characteristics of the flotation tailings, the yield is high, the pollution problem is complex, the utilization rate is low, and how to recycle the flotation tailings and improve the comprehensive utilization rate becomes a problem to be solved urgently.

The utilization of industrial solid waste as a raw material of the porous water-retaining ceramic industry is an important way for utilizing industrial solid waste on a large scale. Patent publication No. CN105541296A proposes a method for preparing a ceramic material by using copper tailings, and the ceramic material of the copper tailings is prepared by pressure forming; patent publication numbers CN109626957A and CN109467389A use graphite tailings as raw materials, and ceramic archaized bricks and ceramic tiles are respectively prepared by pressure forming. The spodumene flotation tailings are solid wastes discharged after lithium resources are selected by lithium production enterprises through flotation or leaching and other processes, contain a large amount of silicate minerals, and mainly comprise SiO as a chemical component₂The proportion is up to 79.75%, and the main phase composition is rock-making minerals such as quartz and the like. At present, secondary tailings generated after the spodumene flotation tailings are subjected to re-selection are still mainly treated in a stockpiling mode, and the problem of difficult forming caused by improvement of ridge materials and high granularity after spodumene flotation hinders the application of the spodumene flotation tailings in the aspect of porous ceramic materials. On the other hand, the traditional high-pressure forming process is adopted in the patent methods, the traditional process is high in energy consumption and economic cost, the water absorption rate of the prepared ceramic material is low, the energy consumption caused by high-pressure forming can be reduced, the industrial cost for preparing the ceramic material by flotation tailings can be reduced, and the water absorption rate of the ceramic can be improved, so that the technical problem to be overcome is solved.

In addition, the traditional ceramic material preparation has high requirement on the sintering temperature, which is generally higher than 1000 ℃, a large amount of energy is consumed, and how to reduce the sintering temperature of the ceramic material is also a technical problem to be overcome.

If the spodumene flotation tailings can be used for preparing the porous ceramic material by sintering at a relatively low temperature, the burden of treating the tailings of lithium production enterprises can be reduced, the source of porous ceramic raw materials can be expanded, and the sintering temperature of the traditional ceramic material can be effectively reduced. Therefore, how to provide a method for preparing a high-water-absorption porous ceramic material by sintering spodumene flotation tailings at a low temperature is a technical problem to be solved urgently.

Disclosure of Invention

The invention aims to solve the technical problems and provides a method for preparing a high-water-absorption porous ceramic material by sintering spodumene flotation tailings at a low temperature. The method successfully prepares the high-water-absorption porous ceramic material with excellent mechanical properties, greatly saves the energy consumption for sintering the high-water-absorption porous ceramic material at high temperature, omits the ball milling process and the pressure forming process which are needed by tailing raw materials, simplifies the preparation process, and has high utilization rate of spodumene flotation tailings.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a method for preparing a porous ceramic material by low temperature sintering of spodumene flotation tailings, the method comprising the steps of:

(1) weighing the following raw materials in percentage by mass of total solids: 65-75% of spodumene flotation tailings, 10-12% of green body bonding materials and 15-25% of high-temperature bonding materials; adding water into the solid raw materials, mixing and stirring to be in a slurry state to obtain slurry; the green body bonding material is a mixture of sodium carboxymethylcellulose and kaolin, and the mass ratio of the green body bonding material to the kaolin is 1: 19, the high-temperature bonding material is a mixture of low-melting-point glass powder and borax, the mass ratio of the high-temperature bonding material to the borax is 5: 1-2, and the addition amount of water is 0.8 times of the weight of spodumene flotation tailings;

(2) adding a hydrogen peroxide solution with the mass percent of 30% into the slurry obtained in the step (1), adding the hydrogen peroxide solution according to the mass ratio of 5-15 ml/kg of the solid raw material, uniformly stirring, performing normal-pressure injection molding, and standing for 24 hours to fully foam;

(3) and (3) demolding and drying the product obtained in the step (2), and sintering the blank at 550-650 ℃ to obtain the porous ceramic material.

Further, the spodumene flotation tailings are tailings obtained after lithium is extracted by a flotation process or tailings obtained after a leaching process in lithium production enterprises.

Further, the step of demoulding and drying in the step (3) is as follows: drying at 60 deg.C for 48h in an electrothermal blowing drier, taking out, demolding, and drying at 120 deg.C for 24h to obtain the final product.

Further, the sintering process of the green body in the step (3) is as follows: and (3) after the green body sample is cooled to room temperature, placing the green body sample in a high-temperature experimental furnace for normal-pressure sintering, heating to the sintering temperature at the speed of 8 ℃/min, preserving the heat for 1h, cooling to room temperature along with the furnace after sintering is finished, and taking out.

According to the method, the low-temperature glass powder, the borax, the sodium carboxymethylcellulose and the kaolin are added to serve as corresponding bonding materials, and the difficult problem that the spodumene flotation tailings are difficult to form due to large particle size is solved through wet injection molding, the ball milling refining process of raw materials is omitted, the energy consumption is reduced, and the cost for preparing the ceramic material is saved. Wherein, kaolin and sodium carboxymethyl cellulose are used as forming fixing agents of the porous ceramic material, the weight ratio of the sodium carboxymethyl cellulose to the kaolin in the green bonding material is 1: 19, the strength of the dried porous ceramic material green body is greatly enhanced, and the problems of difficult demoulding and easy damage caused by lower strength after the porous ceramic material is dried are solved. The low-melting-point glass powder and the borax form the high-temperature sintering binder, the green body is rapidly expanded and foamed through hydrogen peroxide foaming, the addition of a catalyst manganese dioxide is omitted, the test risk is reduced, the environment is protected (manganese dioxide decomposes into toxic substances, namely trioxypromine tetraoxide at about 535 ℃ and has pollution), the high-water-absorption porous ceramic material with excellent mechanical property is successfully prepared at 550-650 ℃, the energy for sintering the high-water-absorption porous ceramic material at high temperature is greatly saved, and the sintering temperature of the high-water-absorption porous ceramic material can be selectively regulated and controlled by using the melting points of different low-temperature low-melting-point glass powders.

Further, the spodumene flotation tailings are tailings obtained after lithium is extracted by a flotation process or tailings obtained after a leaching process in lithium production enterprises.

Further, the step of demoulding and drying in the step (3) is as follows: drying at 60 deg.C for 48 hr, demoulding, and drying at 120 deg.C for 24 hr.

Further, the sintering process of the green body in the step (3) is as follows: and (3) after the green body sample is cooled to room temperature, placing the green body sample in a high-temperature experimental furnace for normal-pressure sintering, heating to the sintering temperature at the speed of 8 ℃/min, preserving the heat for 1h, cooling to room temperature along with the furnace after sintering is finished, and taking out.

Compared with the prior art, the invention has the following beneficial effects:

(1) the tailings after spodumene flotation are used as main raw materials to prepare the high-water-absorption-rate porous ceramic material, the problem that the spodumene flotation tailings are difficult to treat is solved, the total weight proportion of the spodumene flotation tailings is up to 65-75%, large-scale resource utilization of industrial solid wastes can be realized, and the method has obvious social benefits, environmental benefits and economic benefits.

(2) Aiming at the difficulty that the high-water-absorption porous ceramic material needs to be sintered at high temperature, the invention successfully prepares the high-water-absorption porous ceramic material with excellent mechanical properties at the temperature of 550 ℃, 600 ℃ and 650 ℃ by adding low-temperature low-melting-point glass powder as a high-temperature binder and adding borax according to a certain proportion, and greatly reduces the sintering temperature (generally higher than 1000 ℃) of the ceramic material.

(3) The invention breaks through the technical problem of difficult wet forming of the porous ceramic material, and solves the problem by adding a green bonding material, wherein the bonding material is a mixture of sodium carboxymethyl cellulose and kaolin, and the weight ratio of the sodium carboxymethyl cellulose to the kaolin in the bonding material is 1: 19.

(4) because the used spodumene flotation tailings have certain granularity, the ball milling energy consumption in the production process of the high-water-absorption porous ceramic material can be reduced, a cheap mineral kaolin with finer granularity is used as a binding material, the ball milling energy consumption in the production process of the high-water-absorption porous ceramic material is saved, the granularity characteristic of the spodumene flotation tailings is fully utilized, and the traditional compression molding is replaced by the wet injection molding, so that the compression molding link is saved, the energy consumption is further reduced, the process is simplified, the cost for preparing the high-water-absorption porous ceramic material is saved, and the high economic, social and environmental benefits are achieved.

(5) The product obtained by sintering at low temperature has excellent mechanical property, high water absorption (up to 52 percent) and high porosity (up to 57 percent), can be applied to the fields of bathroom antiskid water permeable bricks, water retention bricks, water absorption materials, building decoration materials and the like, and has high economic, social and environmental benefits.

Drawings

FIG. 1 is a low temperature sintered high water absorption porous ceramic material prepared in example 1 using spodumene flotation tailings as the main raw material. The numbers 1 to 9 in the figure correspond to the patterns obtained in the schemes 1 to 9 in Table 1, respectively.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is described in detail below with reference to the following embodiments, and it should be noted that the following embodiments are only for explaining and illustrating the present invention and are not intended to limit the present invention. The invention is not limited to the embodiments described above, but rather, may be modified within the scope of the invention.

Example 1

The high-water-absorption porous ceramic material is prepared by the following method, wherein the raw materials comprise the following components in parts by weight: the spodumene flotation tailings respectively account for 65 percent, 70 percent and 75 percent of the total solid mass ratio, the high-temperature binding material respectively accounts for 15 percent, 20 percent and 25 percent of the total solid mass, the green binding material accounts for 10 percent of the total solid mass (the mass ratio of the low-melting-point glass powder to the borax in the high-temperature binding material is 5:1, the weight ratio of the sodium carboxymethylcellulose to the kaolin in the green binding material is 1: 19), after the dry materials are mixed and stirred uniformly, water is added into the raw materials to be mixed and stirred, the adding amount of the water is about 0.8 time of the weight of the spodumene flotation tailings, a muddy slurry is prepared, hydrogen peroxide solutions (the concentration is 30 percent) respectively account for 5ml/kg, 10ml/kg and 15ml/kg in volume of the dry materials are weighed by a liquid transfer gun, are poured into the slurry to be mixed and stirred uniformly, injection molding is carried out, and standing is carried out for 24 hours at room temperature to fully foam, and then placing the sample in an electric heating forced air drier to dry for 48h at 60 ℃, taking out and demoulding, continuing to dry for 24h at 120 ℃ after demoulding (fully drying to prevent explosion caused by sudden loss of water in the sintering process), placing the sample in a high-temperature experimental furnace to sinter at normal pressure after the sample of the green body is cooled to room temperature, heating to the sintering temperature of 550 ℃ below zero at the speed of 8 ℃/min, preserving heat for 1h, cooling to room temperature along with the furnace after sintering is finished, and taking out (preventing quenching and cracking). The results of the tests on the bending strength, compression strength, porosity, volume weight and water absorption of the fired product are shown in Table 1.

Example 2

The sample is prepared according to the proportion and the method in the embodiment 1, the temperature is increased from room temperature to the sintering temperature of 600 ℃ at the speed of 8 ℃/min, the temperature is kept for 1h, and the sample is taken out after the sintering is finished and the temperature is cooled to the room temperature along with the furnace. The results of the tests on the bending strength, compression strength, porosity, volume weight and water absorption of the fired product are shown in Table 1.

Example 3

The sample is prepared according to the proportion and the method in the embodiment 1, the temperature is increased from room temperature to the sintering temperature of 650 ℃ at the speed of 8 ℃/min, the temperature is kept for 1h, and the sample is taken out after being cooled to the room temperature along with the furnace after the sintering is finished. The results of the tests on the bending strength, compression strength, porosity, volume weight and water absorption of the fired product are shown in Table 1.

TABLE 1

Comparative example 1

The method of example 1 was followed, wherein the weight ratio of sodium carboxymethylcellulose to kaolin in the green binder material was replaced with 1: 1. 1: 5. 1: 10 other conditions were unchanged, the pattern green body was too sticky to be shaped and demolded.

Comparative example 2

The process of example 1 was followed, wherein the sodium carboxymethylcellulose component of the green binder material was removed and the other conditions were unchanged. The green shapes were formable but the green strengths were too low to be successfully demolded.

Comparative example 3

According to the method of the embodiment 1, the low-melting-point glass powder in the high-temperature bonding material is replaced by the common glass powder, and other conditions are not changed, wherein the sintering temperatures are 550 ℃, 600 ℃, 650 ℃ and 900 ℃ respectively. The test patterns were examined and the results are shown in Table 2.

Comparative example 4

The borax was removed from the high temperature cementitious material by the method of example 1, with the other conditions unchanged. The test patterns were examined and the results are shown in Table 3. The results show that the flexural strength is lower than that of the examples.

TABLE 2

TABLE 3

The flexural strength of the ceramic materials prepared in the above examples and comparative examples is tested according to the bending strength test method of the ceramic material in the national standard GB/T4741-1999, the compressive strength is tested according to the compressive strength test method of the ceramic material in the national standard GB/T4740-1999, the water absorption rate is tested according to the water absorption rate test method of the domestic ceramic in the national standard GB/T3299-2011, and the apparent porosity and the volume weight are tested according to the apparent porosity and the volume weight test method of the porous water-retaining ceramic in the national standard GB/T1966-1996.