A porous ceramic particle based on spodumene flotation tailings, its preparation method and application

Abstract

The application provides a porous ceramicite based on lithium feldspar flotation tailings and a preparation method and application thereof, and belongs to the technical field of water treatment filter materials.The porous ceramicite based on lithium feldspar flotation tailings provided by the application comprises the following raw material components in percentage by weight: 60-75% of lithium feldspar flotation tailings and 25-40% of gasification fine slag.The raw materials of the application are all solid wastes, so the process is simple, the cost is low, the lithium feldspar flotation tailings and the gasification fine slag can be fully utilized, the prepared ceramicite has high porosity and high water absorption, and can be well used as a water treatment filter material.

Description

Technical Field

[0001] This invention belongs to the field of water treatment filter media technology, specifically relating to a porous ceramic particle based on spodumene flotation tailings and its preparation method and application, involving the resource utilization of spodumene flotation tailings and the harmless treatment of gasification fine slag. Background Technology

[0002] Ceramic granules for water treatment possess characteristics such as large specific surface area, low bulk density, high chemical stability, and porous structure that facilitates biofilm formation, making them frequently used in the water treatment field. In wastewater treatment, biological ceramsite reactors can effectively perform pretreatment, improving the efficiency of subsequent processes. Ceramsite filter media can play an effective role in wastewater biological filters and can also serve as a substrate for landscape water bodies and wetlands. Compared with traditional filter media, ceramsite filter media is more economical due to its use of locally sourced materials, especially since it is made from industrial solid waste (tailings, coal-based solid waste, etc.) instead of traditional non-renewable raw materials such as clay or shale. This not only conserves natural resources but also achieves the goal of "treating waste with waste."

[0003] Tailings refer to the waste residue discharged after valuable concentrates are extracted from ore mined from metallic or non-metallic mines in concentrators. These tailings are large in quantity and contain both useful and harmful components. Indiscriminate discharge of tailings not only causes environmental pollution but also leads to resource loss. The resource utilization of tailings is one of the key research directions in the current green economy. Therefore, many researchers have conducted research on adding tailings and other solid wastes to clay to produce ceramsite, and some progress has been made.

[0004] However, in the research on using tailings to produce ceramsite, it is still necessary to add a relatively large amount of raw materials such as clay, bauxite, and silica in order to prepare ceramsite filter media with performance that meets the standards.

[0005] For example, patent document CN 103086741 A provides a biological ceramsite filter material for lead-zinc sulfide ore flotation tailings and its preparation method. Although 80-90 wt% of lead-zinc sulfide ore flotation tailings are added to its raw material formula, 8-18.5 wt% of clay and binder materials are still required to prepare ceramsite filter material with a water absorption rate of more than 23%. Moreover, under this raw material formula, the firing temperature needs to be raised to 1240℃, which has the disadvantage of high firing temperature and low water absorption rate and porosity of the resulting ceramsite filter material.

[0006] In addition, patent document CN 114180870 A discloses a tin tailings ceramsite and its preparation method, which is made by mixing, stirring, granulating, and sintering 30-60% tin tailings powder, 35-55% silica powder, 1-7% alumina powder, and 1-5% gas-generating components. Although this method uses tin tailings to prepare ceramsite, it requires the addition of a large amount of silica and alumina to the raw materials. Furthermore, the water absorption rate of the prepared ceramsite material is only 5.69%, which cannot meet the requirements of high water absorption rate and porosity for water treatment ceramsite filter particles.

[0007] For example, patent document CN 115557775 A discloses a titanium tailings-based ecological ceramsite, which is prepared from 45-75% titanium tailings, 20-45% fly ash from municipal solid waste incineration, and the remainder being waste glass. Although this patent document solves the problem that traditional ceramsite preparation methods require the addition of large amounts of clay and alumina, and uses solid waste to prepare ceramsite, the calcination temperature of this method needs to reach 1110-1150℃ and the calcination time is 1-2 hours. This method has the disadvantages of high calcination temperature and long calcination time. In addition, the porosity of the ceramsite prepared by this method is still relatively low.

[0008] Therefore, existing methods for preparing ceramsite using flotation tailings either require the addition of substances such as clay and silica to the raw materials, resulting in high raw material costs; or they require high firing temperatures and long firing times, resulting in high firing costs. In addition, ceramsite prepared by existing methods generally suffers from low water absorption and porosity.

[0009] my country boasts abundant spodumene resources, ranking second in the world. Flotation is widely used in spodumene beneficiation plants both domestically and internationally, resulting in a large amount of spodumene flotation tailings. Currently, there are no reports of using spodumene flotation tailings to prepare water treatment ceramsite. Therefore, how to prepare water treatment ceramsite using spodumene flotation tailings, and find a method to produce ceramsite filter media entirely from solid waste without adding raw materials such as clay or silica, while simultaneously reducing the firing temperature and time of the ceramsite and improving the water absorption and porosity of the resulting ceramsite, has become an urgent technical problem to be solved. Summary of the Invention

[0010] This invention aims to solve the aforementioned technical problems by providing a porous ceramsite based on spodumene flotation tailings, its preparation method, and its application. The technical objective of this invention is to provide a method for preparing porous ceramsite for water treatment using spodumene flotation tailings, addressing the issues of high raw material costs associated with the addition of clay, silica, or other raw materials in existing ceramsite preparation methods, and the high processing costs resulting from long sintering temperatures and times when using solid waste. Simultaneously, this invention significantly improves the water absorption rate and porosity of existing ceramsite.

[0011] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0012] The present invention first provides a porous ceramsite based on spodumene flotation tailings, which, by weight percentage, comprises the following raw material components: 60-75% spodumene flotation tailings and 25-40% gasification fine slag.

[0013] Furthermore, the porous ceramsite comprises the following raw material components by weight percentage: 60% spodumene flotation tailings and 40% gasification fine slag.

[0014] Furthermore, the chemical composition of the spodumene flotation tailings, by weight percentage, includes the following components:

[0015] SiO275.28%, Al2O315.64%, Na2O 4.57%, MgO 0.02%, K2O3.61%, Fe2O30.46%, CaO 0.09%.

[0016] Furthermore, the chemical composition of the gasified fine slag, by weight percentage, includes the following components:

[0017] SiO234.22%, Al2O317.29%, Na2O 3.63%, MgO 1.62%, K2O1.41%, Fe2O317.71%, CaO 14.39%.

[0018] Furthermore, the porous ceramsite has a porosity of 47.12–52.35% and a water absorption rate of 28.01–32.47%.

[0019] The second objective of this invention is to provide a method for preparing porous ceramsite based on spodumene flotation tailings as described in any of the preceding claims, comprising the following steps:

[0020] S1: Dry the spodumene flotation tailings and gasification slag raw materials to constant weight;

[0021] S2: Weigh out the spodumene flotation tailings and gasification slag according to the raw material ratio and mix them evenly.

[0022] S3: Add deionized water to the mixed raw materials, stir evenly, and then send it to the granulator for granulation. Then polish it to obtain raw material balls.

[0023] S4: Dry the raw material balls;

[0024] S5: After drying, the raw material pellets are heated to 400-500℃ for 20 minutes at a heating rate of 10℃ / min. Then, they are kept at 1050-1100℃ for 10-30 minutes. After calcination, the temperature is lowered with the furnace. When the temperature drops below 100℃, the finished ceramsite is taken out.

[0025] Furthermore, the particle size range of the spodumene flotation tailings and gasification slag in step S1 is 50 mesh to 200 mesh.

[0026] Furthermore, the amount of deionized water added in step S3 is 25% of the total weight of the mixed raw materials.

[0027] Furthermore, the drying temperature in step S4 is 105°C.

[0028] A third objective of this invention is to provide porous ceramic particles as described above, or their application as water treatment filter media.

[0029] The beneficial effects of this invention are as follows:

[0030] 1) In the existing process of preparing ceramsite using industrial solid waste as raw material through high-temperature calcination, either the sintering temperature is too high or the residence time is too long, or the raw materials need to be supplemented with clay, silica and other raw materials. However, the present invention uses solid waste to prepare ceramsite, and the standard ceramsite product can be obtained at a calcination temperature of 1050℃~1100℃ and a sintering residence time of 10~30min.

[0031] 2) This invention uses spodumene flotation tailings and gasification slag as raw materials, all of which are solid waste. This process is not only simple and low-cost, but also allows for the full utilization of spodumene flotation tailings and gasification slag. While turning "waste" into treasure, it not only saves valuable resources such as clay and shale, but also avoids the large-scale discharge and accumulation of spodumene flotation tailings and gasification slag, reducing environmental pollution and achieving the goals of resource utilization, harmlessness, and reduction of solid waste. It also realizes the transformation of waste into treasure and the treatment of waste with waste, while responding to national policies and reducing the environmental burden.

[0032] 3) The ceramsite prepared by this invention has the characteristics of high water absorption and high porosity. Attached Figure Description

[0033] Figure 1 This is a flowchart of the preparation of water treatment ceramic particles using spodumene flotation tailings and gasification fine slag, provided in an embodiment of the present invention.

[0034] Figure 2 This is a porous ceramic particle material prepared in Example 1 using spodumene flotation tailings and gasification slag as raw materials.

[0035] Figure 3 This is a SEM microstructure image of the porous ceramic aggregate material prepared in Example 1. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described in detail below with reference to embodiments. It should be noted that the following embodiments are for explanation and illustration only and are not intended to limit the invention. Non-essential improvements and adjustments made by those skilled in the art based on the above description are still within the scope of protection of this invention.

[0037] According to the standard for artificial ceramsite filter media for water treatment (CJ / T 299—2008), the sum of the breakage rate and wear rate, mud content, hydrochloric acid solubility, porosity, and specific surface area of ​​the ceramsite filter media should meet the requirements of Table 1. Furthermore, the water content added during the mixing stage has a significant impact on the preparation of raw material balls. When the water content is too high, the obtained raw material balls are too soft, losing the necessary strength, and are prone to sticking and deformation during polishing. Conversely, when the water content is too low, the raw material balls extruded by the granulator are easily loose, and it also easily causes clogging of the granulator. The performance indicators of the water treatment ceramsite of this invention meet the requirements for ceramsite filter media for water treatment, and all exceed the standard indicators.

[0038] Table 1. Item Indicators of Artificial Ceramic Filter Media

[0039]

[0040]

[0041] The water treatment ceramsite of the present invention is prepared from the following raw materials by mass percentage: 60-75 wt.% spodumene flotation tailings and 25-40 wt.% gasification fine slag.

[0042] The main chemical composition of the raw materials involved in the following examples is shown in Table 2.

[0043] Table 2: Main Chemical Composition of Raw Materials (wt.%)

[0044]

[0045] Example 1

[0046] A method for preparing porous ceramsite based on spodumene flotation tailings, wherein the raw material composition by weight percentage is: 60% spodumene flotation and 40% gasification fine slag;

[0047] Its preparation method includes the following steps:

[0048] S1: Place the raw materials in an oven and dry them to a constant weight. The oven temperature is 105℃ and the drying time is 12 hours.

[0049] S2: Weigh the corresponding weight of raw materials according to the formula ratio and mix them thoroughly;

[0050] S3: Pour the mixed raw materials into a stainless steel container, add 25% deionized water, mix well and let stand for 10 minutes.

[0051] S4: Put the mixed raw materials into a granulator to granulate and form them. The diameter of the granulator's outlet is 6mm.

[0052] S5: After placing the formed raw material balls in the oven for 5 minutes, transfer them to the polishing machine and roll them for 20 minutes to make the particles more rounded.

[0053] S6: Use a sieve to remove unqualified raw material balls, and dry the raw material balls in an oven at 105℃;

[0054] S7: Place the dried raw material pellets in an electric resistance furnace for calcination. The heating rate is 10℃ / min, the preheating temperature is 450℃, the preheating time is 20min, the calcination temperature is 1050℃, and the holding time is 30min. After calcination, the furnace is cooled down. When the temperature drops below 100℃, the finished ceramsite is taken out and allowed to cool down at room temperature before packaging.

[0055] The performance of the calcined ceramsite in this example was tested, and the sum of the breakage rate and abrasion rate was 0.17%, with a specific surface area of ​​3.548 × 10⁻⁶. 4 cm 2 / g, porosity 52.35%, hydrochloric acid solubility 0.68%, water absorption rate 32.47%, meeting the main performance standard requirements of CJ / T 299—2008 for water treatment ceramic filter media.

[0056] Example 2

[0057] The difference between this embodiment and Embodiment 1 is that the raw material composition is 65% spodumene flotation and 35% gasification fine slag, while other operating steps and conditions remain unchanged.

[0058] The performance of the calcined ceramsite in this example was tested, and the sum of the breakage rate and abrasion rate was 0.17%, with a specific surface area of ​​3.261 × 10⁻⁶. 4 cm 2 / g, porosity 50.54%, hydrochloric acid solubility 0.44%, water absorption rate 30.79%, meeting the main performance standard requirements of CJ / T 299—2008 for water treatment ceramic filter media.

[0059] Example 3

[0060] The difference between this embodiment and Embodiment 1 is that the raw material composition is 70% spodumene flotation and 30% gasified fine slag, the preheating temperature is 500℃, the roasting temperature is 1100℃, the roasting time is 20min, and other operating steps and conditions remain unchanged.

[0061] The performance of the calcined ceramsite in this example was tested, and the sum of the breakage rate and wear rate was 0.17%, with a specific surface area of ​​3.076 × 10⁻⁶. 4 cm 2 / g, porosity 49.27%, hydrochloric acid solubility 0.48%, water absorption rate 29.40%, meeting the main performance standard requirements of CJ / T 299—2008 for water treatment ceramic filter media.

[0062] Example 4

[0063] The difference between this embodiment and Embodiment 1 is that the raw material composition is 75% spodumene flotation and 25% gasified fine slag, the preheating temperature is 400℃, the roasting temperature is 1080℃, the roasting time is 10min, and other operating steps and conditions remain unchanged.

[0064] The performance of the calcined ceramsite in this example was tested, and the sum of the breakage rate and wear rate was 0.27%, with a specific surface area of ​​2.760 × 10⁻⁶. 4 cm 2 / g, porosity 47.12%, hydrochloric acid solubility 0.63%, water absorption rate 28.01%, meeting the main performance standard requirements of CJ / T 299—2008 for water treatment ceramic filter media.

[0065] Comparative Example 1

[0066] The water treatment ceramsite raw material in this comparative example uses 100% spodumene flotation tailings, and the preparation method is as follows:

[0067] S1: Place the raw materials in an oven and dry them to a constant weight. The oven temperature is 105℃ and the drying time is 12 hours.

[0068] S2: Pour the dried spodumene flotation tailings into a stainless steel container, add 25% deionized water, mix well and let stand for 10 minutes.

[0069] S3: Put the raw material into a granulator to granulate and form it. The diameter of the granulator's outlet is 6mm.

[0070] S4: After placing the formed raw material balls in the oven for 5 minutes, transfer them to the polishing machine and roll them for 20 minutes to make the particles more rounded.

[0071] S5: Use a sieve to remove unqualified raw material balls, and dry the raw material balls in an oven at 105℃;

[0072] S6: Place the dried ceramsite in a resistance furnace for calcination. The heating rate is 10℃ / min, the preheating temperature is 450℃, the preheating time is 20min, the calcination temperature is 1100℃, and the calcination time is 20min. After calcination, the furnace is cooled down. When the temperature drops below 100℃, the finished ceramsite is taken out, cooled to room temperature, and packaged.

[0073] The performance of the calcined ceramsite from this comparative example was tested, and the sum of the breakage rate and wear rate was 0.11%, with a specific surface area of ​​0.932 × 10⁻⁶. 4 cm 2 / g, porosity 23.12%, hydrochloric acid solubility 0.57%, water absorption 2.59%. Because only spodumene flotation tailings were used as raw material, the content of metal oxides used as fluxing agents in spodumene flotation tailings is low, and no pore-forming agents are present. This results in a high firing temperature for the ceramsite, leading to low porosity and water absorption. Consequently, the main performance characteristics of the resulting ceramsite product do not meet the main performance standards for water treatment ceramsite filter media in CJ / T 299—2008.

[0074] Comparative Example 2

[0075] The difference between this comparative example and Comparative Example 1 is that the raw material for water treatment ceramic particles is 100% gasification fine slag, while other operating steps and conditions remain unchanged.

[0076] The performance of the calcined ceramsite from this comparative example was tested, and the sum of the breakage rate and wear rate was 0.23%, with a specific surface area of ​​1.437 × 10⁻⁶. 4 cm 2 The particle size distribution is as follows: / g, porosity 25.54%, hydrochloric acid solubility 0.87%, water absorption 3.67%. Because only gasification slag was selected as raw material, the SiO2 content in the gasification slag did not meet the standard requirements, resulting in insufficient support for the ceramsite skeleton. Furthermore, the high content of metal oxides as fluxing agents caused the liquid phase generated by the melting of metal oxides to fill the pores after the residual carbon was burned off, leading to ceramsite shrinkage. Consequently, both porosity and water absorption were low, and the main performance characteristics of the resulting ceramsite product did not meet the main performance standards for water treatment ceramsite filter media in CJ / T 299—2008.

[0077] Comparative Example 3

[0078] The difference between this comparative example and Comparative Example 1 is that the raw material for the water treatment ceramsite is 90% spodumene flotation tailings and 10% gasification fine slag, while other operating steps and conditions remain unchanged.

[0079] The performance of the calcined ceramsite from this comparative example was tested, and the sum of the breakage rate and wear rate was 0.18%, with a specific surface area of ​​1.523 × 10⁻⁶. 4 cm 2The particle size distribution is 10.67%, the porosity is 29.83%, the hydrochloric acid solubility is 0.67%, and the water absorption rate is 10.67%. The main performance characteristics of the prepared ceramsite product do not meet the main performance standards of CJ / T 299—2008 for water treatment ceramsite filter media.

[0080] Comparative Example 4

[0081] Similar to the treatment in Comparative Example 3, the raw material for water treatment ceramsite was changed to 20% spodumene flotation tailings and 80% gasification fine slag, while other operating steps and conditions remained unchanged.

[0082] The performance of the calcined ceramsite from this comparative example was tested, and the sum of the breakage rate and wear rate was 0.12%, with a specific surface area of ​​1.923 × 10⁻⁶. 4 cm 2 The particle size distribution is 1 / g, the porosity is 38.83%, the hydrochloric acid solubility is 0.72%, and the water absorption rate is 19.49%. The main performance characteristics of the prepared ceramsite product do not meet the main performance standard requirements of CJ / T 299—2008 for water treatment ceramsite filter media.

[0083] Comparative Example 5

[0084] Referring to the scheme in patent CN 115557775 A, the raw material composition of the ceramsite, by mass percentage, is selected as follows: 45% spodumene flotation tailings, 45% municipal solid waste incineration fly ash, and 10% waste glass. Water treatment ceramsite was prepared according to the preparation process of Example 1 of this invention. The results showed that the sum of the breakage rate and wear rate of the ceramsite was 0.18%, and the specific surface area was 2.715 × 10⁻⁶. 4 cm 2 / g, porosity 42.24%, hydrochloric acid solubility 0.70%, water absorption rate 21.96%.

[0085] In summary, under the same conditions, by proportioning spodumene flotation tailings and gasification slag according to the chemical composition range of the raw materials of this invention, a "1+1>>2" effect can be achieved. Conversely, it is difficult to prepare ceramsite with high water absorption, high porosity, and excellent performance.

Claims

1. A porous ceramsite based on lithium feldspar flotation tailings, characterized in that, The porous ceramsite is composed of the following raw material components by weight percentage: lithium aluminosilicate flotation tailings 60-75%, gasification fine slag 25-40%; the porosity of the porous ceramsite is 47.12-52.35%, and the water absorption rate is 28.01-32.47%.

2. The porous ceramsite based on lithium spodumene flotation tailings according to claim 1, characterized in that, The porous ceramsite is composed of the following raw material components by weight percentage: lithium aluminosilicate flotation tailings 60%, gasification fine slag 40%.

3. The porous haydite based on lithium spodumene flotation tailings according to claim 1, characterized by that, The chemical composition of the lithium aluminosilicate flotation tailings includes the following components by weight percentage: SiO2 75.28%, Al2O3 15.64%, Na2O 4.57%, MgO 0.02%, K2O 3.61%, Fe2O3 0.46%, CaO 0.09%.

4. The porous haydite based on lithium spodumene flotation tailings according to claim 1, characterized in that, The chemical composition of the gasification fine slag includes the following components by weight percentage: SiO2 34.22%, Al2O3 17.29%, Na2O 3.63%, MgO 1.62%, K2O 1.41%, Fe2O3 17.71%, CaO 14.39%.

5. A method for the production of porous ceramsite based on lithium feldspar flotation tailings according to any one of claims 1 to 4, characterized by, The method comprises the following steps: S1: drying the lithium aluminosilicate flotation tailings and the gasification fine slag raw materials to constant weight; S2: weighing the lithium aluminosilicate flotation tailings and the gasification fine slag according to the raw material ratio and mixing them uniformly; S3: adding deionized water to the mixed raw materials, stirring them uniformly, and then sending them to a granulator for granulation, and then polishing to obtain green balls; S4: drying the green balls; S5: preheating the dried green balls to 400-500°C at a temperature rising rate of 10°C / min for 20 min, and then keeping the temperature at 1050-1100°C for 10-30 min, and then cooling the calcined product in the furnace until the temperature is below 100°C, and then taking out the ceramsite product.

6. The production method according to claim 5, wherein The particle size of the lithium aluminosilicate flotation tailings and the gasification fine slag in step S1 is 50-200 mesh.

7. The preparation method according to claim 5, characterized in that, The amount of the deionized water added in step S3 accounts for 25% of the total weight of the mixed raw materials.

8. The preparation method according to claim 5, characterized in that, The drying temperature in step S4 is 105°C.

9. The porous ceramsite of any one of claims 1-4 or prepared by the method of any one of claims 5-8 for use as a water treatment filter.

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