阅读说明：本技术 一种利用锂辉石浮选尾矿制备免烧地聚物材料的方法 (Method for preparing baking-free geopolymer material by utilizing spodumene flotation tailings ) 是由 徐龙华 杨洁 巫侯琴 金娇 于 2020-11-11 设计创作，主要内容包括：本发明公开了一种利用锂辉石浮选尾矿制备免烧地聚物材料的方法,包括以下步骤：(1)按重量百分比称取75～80％锂辉石浮选尾矿和20％～25％的活性调节剂；(2)向步骤(1)的原料中添加占原料总重量30～50％的增强剂,混合均匀；(3)加入模数为3.3、质量浓度40％的硅酸钠溶液,并搅拌至稀泥状,所述硅酸钠溶液的加入量为锂辉石浮选尾矿重量的40％；(4)将步骤(3)所得物进行常压注模成型；(5)将步骤(4)所得物采用烘干装置进行烘干,取出后自然冷却至室温,制得锂辉石浮选尾矿免烧地聚物材料。本发明方法制备了力学性能优异的免烧地聚物材料,节省了高温烧结制备材料的能耗,同时锂辉石浮选尾矿的利用率高。(The invention discloses a method for preparing a baking-free geopolymer material by utilizing spodumene flotation tailings, which comprises the following steps: (1) weighing 75-80% of spodumene flotation tailings and 20-25% of activity regulator according to weight percentage; (2) adding a reinforcing agent accounting for 30-50% of the total weight of the raw materials into the raw materials in the step (1), and uniformly mixing; (3) adding a sodium silicate solution with the modulus of 3.3 and the mass concentration of 40%, and stirring the mixture to be in a slurry shape, wherein the adding amount of the sodium silicate solution is 40% of the weight of the spodumene flotation tailings; (4) performing normal pressure injection molding on the product obtained in the step (3); (5) and (4) drying the product obtained in the step (4) by using a drying device, taking out the product, and naturally cooling the product to room temperature to obtain the sintering-free geopolymer material of the spodumene flotation tailings. The method disclosed by the invention has the advantages that the baking-free geopolymer material with excellent mechanical properties is prepared, the energy consumption for preparing the material by high-temperature sintering is saved, and meanwhile, the utilization rate of spodumene flotation tailings is high.)

1. A method for preparing a baking-free geopolymer material by utilizing spodumene flotation tailings is characterized by comprising the following steps of:

(1) respectively weighing 75-80% of spodumene flotation tailings and 20-25% of activity regulator as raw materials according to weight percentage, wherein the activity regulator is a mixture of fly ash and metakaolin according to a weight ratio of 1: 14;

(2) adding a reinforcing agent accounting for 30-50% of the total weight of the raw materials into the raw materials in the step (1), and uniformly mixing; the reinforcing agent is a mixture of quartz sand and standard sand in a weight ratio of 1: 1;

(3) adding a sodium silicate or potassium silicate solution with the modulus of 3.3 and the mass concentration of 40% into the product obtained in the step (2), and stirring the mixture to be in a slurry shape, wherein the adding amount of the sodium silicate or potassium silicate solution is 40% of the weight of the spodumene flotation tailings;

(4) performing normal pressure injection molding on the product obtained in the step (3);

(5) and (4) drying the product obtained in the step (4) by using a drying device, taking out the product, and naturally cooling the product to room temperature to obtain the sintering-free geopolymer material of the spodumene flotation tailings.

2. The method according to claim 1, wherein the spodumene flotation tailings obtained in the step (1) 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 in the step (2), the particle size of the reinforcing agent mixture is 5-40 meshes.

4. The method as claimed in claim 1, wherein the injection molding bar mold in the step (4) is a six-up mold having a size of 10 x 60mm and a single column mold having a column pattern of Φ 20 x 20.

5. The method of claim 1, wherein the step of drying in step (5) comprises: and laying a layer of absorbent paper at the bottom of the mold for injecting the film, placing the sample in a drying device for drying for 12 hours at 60 ℃ after injection molding, then continuously drying for 48 hours in the reverse direction, and taking out and demoulding.

6. The method of claim 5, wherein the step of drying in step (5) further comprises: and after demoulding, continuously drying for 48 hours at the temperature of 60 ℃.

7. The method of claim 1, wherein the drying device in step (5) is an electric hot air drying oven.

Technical Field

The invention belongs to the technical field of preparing non-fired materials by using industrial solid waste resources, and particularly relates to a method for preparing a non-fired geopolymer material by using spodumene flotation tailings.

Background

With the development of industrial society, environmental problems brought by the development of a large number of resources are increasingly prominent, how to properly treat solid wastes becomes a hot problem in the current society, flotation tailings are used as special solid wastes in the solid wastes due to the characteristics of the flotation tailings, and the problems of huge yield, complex pollution problem and low utilization rate exist. How to recycle the flotation tailings and improve the comprehensive utilization rate of the flotation tailings becomes a problem to be solved urgently.

The preparation of related materials by utilizing industrial solid waste tailings is an important way for treating industrial solid waste. In the patent publication CN105541296A, a method for preparing a ceramic material from copper tailings is proposed, which is to prepare a copper tailings ceramic material by pressure forming; in patent publications CN109626957A and CN109467389A, graphite tailings are used as raw materials, and ceramic archaized bricks and ceramic tiles are prepared by pressure forming. The traditional high-pressure forming process is adopted in the patent methods, high-temperature sintering is needed, the process is high in energy consumption and economic cost, and the technical problem to be overcome in the field is solved if the energy consumption caused by high-pressure forming and sintering is reduced and the huge energy consumption of materials prepared from flotation tailings is reduced.

It is assumed that if the sintering-free geopolymer material can be prepared by utilizing spodumene flotation tailings, the burden of treating the tailings of lithium production enterprises can be reduced, geopolymer raw material sources can be expanded, and the energy consumption caused by high-temperature sintering can be effectively reduced. However, at present, there is no referable preparation method, and how to provide a method for preparing a baking-free geopolymer material by utilizing spodumene flotation tailings becomes 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 baking-free geopolymer material by utilizing spodumene flotation tailings. The method successfully prepares the baking-free geopolymer material with excellent mechanical property, greatly saves the energy consumption for preparing the material by high-temperature sintering, omits the ball milling process and the pressure molding process which are needed by tailing raw materials, optimizes the preparation process, overcomes the deformation problem in the drying 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 baking-free geopolymer material by utilizing spodumene flotation tailings comprises the following steps:

(1) respectively weighing 75-80% of spodumene flotation tailings and 20-25% of activity regulator as raw materials according to weight percentage, wherein the activity regulator is a mixture of fly ash and metakaolin according to a weight ratio of 1: 14;

(2) adding a reinforcing agent accounting for 30-50% of the total weight of the raw materials into the raw materials in the step (1), and uniformly mixing; the reinforcing agent is a mixture of quartz sand and standard sand in a weight ratio of 1: 1;

(3) adding a sodium silicate or potassium silicate solution with the modulus of 3.3 and the mass concentration of 40% into the product obtained in the step (2), and stirring the mixture to be in a slurry shape, wherein the adding amount of the sodium silicate or potassium silicate solution is 40% of the weight of the spodumene flotation tailings;

(4) performing normal pressure injection molding on the product obtained in the step (3);

(5) and (4) drying the product obtained in the step (4) by using a drying device, taking out the product, and naturally cooling the product to room temperature to obtain the sintering-free geopolymer material of the spodumene flotation tailings.

The method of the invention realizes the successful preparation of the baking-free geopolymer material with excellent mechanical property under the conditions of baking-free and no need of pressure molding, greatly saves the energy for preparing the material by high-temperature sintering, and overcomes the problem that the material is easy to deform. The method selects the mixture of the fly ash and the metakaolin as a granularity and volcanic ash activity regulator, selects the quartz sand to be compounded with the standard sand to improve the compressive strength of the geopolymer, strictly controls the process conditions and the raw material dosage in each step, and can maximally ensure the quality of the obtained burning-free geopolymer through an optimized process obtained after a large amount of groping. The invention also saves the ball milling process and the pressure forming process of the raw materials, saves energy and has the utilization rate of spodumene flotation tailings as high as 80 percent.

Further, the spodumene flotation tailings obtained in the step (1) are tailings obtained after lithium is extracted by a flotation process or tailings obtained after a leaching process in lithium production enterprises.

Further, in the step (2), the particle size of the reinforcing agent mixture is 5-40 meshes.

Further, the injection molding strip mold in the step (4) is a six-part mold with the size of 10 × 10 × 60mm, and a single column mold with the column pattern of Φ 20 × 20 is selected.

Further, the drying step in step (5) includes: and laying a layer of absorbent paper at the bottom of the mold for injecting the film, placing the sample in a drying device for drying for 12 hours at 60 ℃ after injection molding, then continuously drying for 48 hours in the reverse direction, and taking out and demoulding.

Further, the step of drying in step (5) further includes: and after demoulding, continuously drying for 48 hours at the temperature of 60 ℃.

Further, the drying device in the step (5) is an electric heating air blowing drying box.

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

(1) the non-fired geopolymer material is prepared by using tailings obtained after spodumene flotation as a main raw material, so that the problem of difficulty in treatment of the spodumene flotation tailings is solved, wherein the spodumene flotation tailings account for 75-80% of the total weight, the large-scale resource utilization of industrial solid wastes can be realized, and the non-fired geopolymer material has obvious social benefits, environmental benefits and economic benefits.

(2) The invention breaks through the technical problem that the preparation of the material by utilizing the tailings must be pressed and molded and sintered at high temperature, and aims at the difficulty, the geopolymer material with excellent chemical property is successfully prepared under the condition of no firing by an alkali excitation mode, so that the energy consumption is greatly reduced.

(3) The invention breaks through the technical problem of low mechanical property of geopolymer materials caused by fine granularity, solves the problem by adding a mixture of standard sand and quartz sand (5-40 meshes) in a mass ratio of 1:1, and obtains the geopolymer materials with excellent mechanical property.

(4) The spodumene flotation tailings have certain granularity, so that the ball milling energy consumption in the production process of the high-water-absorption porous ceramic material can be reduced, and a low-cost mineral metakaolin with finer granularity is used as a binding material, so that the ball milling energy consumption in the production process of a geopolymer material is saved, and the granularity characteristic of the spodumene flotation tailings is fully utilized; the invention replaces the traditional pressure forming by adopting the wet injection molding, which saves the pressure forming link, further reduces the energy consumption, simplifies the process, saves the cost for preparing the porous ceramic material with high water absorption rate and has very high economic, social and environmental benefits.

(5) The problem of deformation in the drying process is solved by a special drying method, and the geopolymer is easy to deform during drying in the actual production and preparation.

(6) The alkaline-activated baking-free geopolymer product has excellent mechanical property, smaller deformation and regular molding, can be applied to the fields of baking-free bricks, geopolymer, hazardous waste solidification, industrial solid waste treatment, building decoration materials and the like, and has high economic, social and environmental benefits.

Drawings

FIG. 1 is a unfired geopolymer material from spodumene flotation tailings prepared according to formulation number 3 of example, wherein the left side is a bar form (10X 60mm) for testing the flexural strength of the test specimen and the right side is a cylindrical test specimen (phi 20X 20mm) for testing the compressive strength of the test specimen.

FIG. 2 is a non-fired geopolymer material of spodumene flotation tailings prepared with the formulation number 7 in Table 2.

FIG. 3 is a flow chart of two drying methods in example 1 and comparative example 7 of the present invention.

Fig. 4 shows samples obtained in two drying modes, wherein the left side is a sample prepared by a conventional drying and demolding mode, and the right side is a sample prepared by the drying mode of the invention.

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 baking-free geopolymer material is prepared by weighing the raw materials according to the raw material formulas in the table 1, wherein the raw materials in the table 1 comprise the following components in parts by weight: the mass ratio of the spodumene flotation tailings to the total solid is 75% (serial numbers 1-3) and 80% (serial numbers 4-6), respectively, and the mass ratio of the corresponding mixture of the fly ash and the metakaolin (the mass ratio is 1:14) to the total solid is 25% (serial numbers 1-3) and 20% (serial numbers 4-6), respectively. In addition, a mixture (5-40 meshes) of quartz sand and standard sand is prepared from the following raw materials in a mass ratio of 1:1, the addition amounts thereof were 30% (Nos. 1 and 4), 40% (Nos. 2 and 5), and 50% (Nos. 3 and 6), respectively, based on the total solid mass. After the dry materials are uniformly mixed, a sodium silicate solution (with the mass concentration of 40%) with the modulus of 3.3 is added and stirred to be in a slurry shape, wherein the adding amount of the sodium silicate solution is about 40% of the weight of spodumene flotation tailings (40 ml is taken in table 1).

And (3) padding a piece of absorbent paper (replacing filter paper) on the bottom of the die by normal pressure injection molding, drying at 60 ℃ for 12h, and then reversely drying for 48 h. And demolding and drying the obtained product for 48 hours, taking out, and naturally cooling to room temperature to obtain the spodumene flotation tailing geopolymer material.

The flexural strength and the compressive strength of the obtained non-fired product are tested, the specific test method refers to the flexural strength test method of the ceramic material GB/T4741-1999 and the compressive strength test method of the ceramic material GB/T4740-1999, and the test results are shown in Table 1.

TABLE 1

FIG. 1 is a physical diagram of the unfired geopolymer material of spodumene flotation tailings prepared according to formulation No. 3 in the above example. As can be seen from the figure, the surface of the obtained sample has large particles, namely quartz sand and standard sand, and the effect of enhancing the mechanical property can be achieved.

Tests were conducted by replacing the sodium silicate solution in the formulation of table 1 above with a potassium silicate solution, and the results were substantially the same as those in table 1. It is shown that the spodumene flotation tailing geopolymer material of the invention can be well obtained by excitation with potassium silicate solution.

Comparative example 1

According to the preparation method of the example 1, the spodumene flotation tailings with the mass accounting for 75% of the total solid mass are tested, the ratio of quartz sand to standard sand is adjusted, corresponding raw material formulas are searched, the formulas are shown as 7, 8 and 9 in the table 2, and the compression strength of the obtained material is lower than that of the example.

Comparative example 2

The proportions of fly ash and metakaolin were adjusted according to the preparation method of example 1, and the formulations are shown in tables 2 at 10, 11 and 12, and the compression strength of the resulting material was tested to be lower than that of the examples. Wherein the pattern green body can not be molded after the metakaolin and the fly ash are removed, and is difficult to dry.

TABLE 2

Fig. 2 is a physical diagram of the unfired geopolymer material prepared from the spodumene flotation tailings formula No. 7 in table 2, and it can be seen from the appearance of fig. 2 that the geopolymer material has a smooth surface and no particles, and the mechanical properties of the obtained material are reduced compared with those of fig. 1 corresponding to the condition that quartz sand and standard sand are not added in the formula.

Comparative example 3

According to the method of the example 1, the metakaolin with low melting point is replaced by the ordinary kaolin, and other conditions are unchanged, and tests show that the flexural strength and the compressive strength of the obtained material are both less than 10MPa and far lower than the schemes in the example table 1.

Comparative example 4

According to the method of the embodiment 1, the metakaolin with low melting point is replaced by the fly ash, and other conditions are unchanged, and tests show that the flexural strength and the compressive strength of the obtained material are both less than 10MPa and far lower than the scheme in the embodiment table 1.

Comparative example 5

According to the method of the embodiment 1, the modulus of the sodium silicate is replaced by 2.7, 2.1, 1.5, 0.9 and 0.3, other conditions are unchanged, and the flexural strength and the compressive strength of the obtained material are both less than 20MPa and are far lower than the scheme in the embodiment table 1.

Comparative example 6

According to the method of the embodiment 1, the concentration of the sodium silicate solution is replaced by 20%, 10%, 5% and 1%, other conditions are unchanged, and the flexural strength and the compressive strength of the obtained material are both less than 20MPa and are far lower than the scheme in the embodiment table 1.

Comparative example 7

According to the method of example 1, the formulas of serial No. 2 in table 1 and serial No. 7 in table 2 were respectively adopted, the drying step was changed to injection molding and then direct drying (see fig. 3, wherein the operations of filling absorbent paper at the bottom of the mold and reverse drying were not performed), and it was found that the obtained samples were all significantly bent (see the photograph of the product after demolding at the upper right corner of fig. 3, the sample obtained by subjecting the formula of serial No. 7 at the upper layer to two drying methods, and the sample obtained by subjecting the formula of serial No. 2 at the lower layer to two drying methods), and the drying results of the multiple samples were shown in fig. 4, wherein the left side is the sample obtained by the conventional drying method (direct drying after injection molding), and the right side is the sample obtained by using the drying method of example 1 (sample of serial no.