Method for separation and utilization of fly ash aluminum-silicon, and tobermorite and silicon oxide obtained through method

A technology for separation of tobermorite and aluminum silicon, which is applied in the direction of silicon oxide, silicon dioxide, calcium/strontium/barium chloride, etc., can solve the problem of low added value of aluminum extraction from fly ash, and achieve the goal of increasing added value Effect

Active Publication Date: 2015-07-29

CHNA ENERGY INVESTMENT CORP LTD +1

6 Cites 1 Cited by

AI-Extracted Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to overcome the defect of low added value of fly ash to extra...

Abstract

The present invention discloses a method for separation and utilization of fly ash aluminum-silicon. The method comprises: (1) contacting fly ash and an alkaline solution to carry out a pre-desilication reaction, and carrying out solid-liquid separation to obtain a desilication solution and desilication fly ash; (2) mixing the desilication fly ash, quick lime and sodium carbonate, sintering to obtain a clinker, and carrying out dissolution on the clinker to obtain a sodium aluminate crude solution and basic calcium silicate; (3) carrying out desilication, carbonation and calcination on the sodium aluminate crude solution to obtain alumina; and (4) adding the basic calcium silicate to the desilication solution obtained in the step (1), adding lime milk to carry out combined causticization dealkalization, and carrying out solid-liquid separation to obtain the tobermorite and the alkaline solution. The present invention further discloses the tobermorite and the silicon oxide obtained by using the method. With the method of the present invention, the added value of the aluminum extraction of the fly ash is substantially improved.

Application Domain

SilicaCalcium/strontium/barium chlorides +3

Technology Topic

CarbonationSodium carbonate +9

Image

Examples

Experimental program(3)

Example Embodiment

[0058] Example 1

[0059] This example is used to illustrate the method for the separation and utilization of aluminum and silicon in fly ash of the present invention.

[0060] (1) Grind fly ash to 250 mesh, remove iron by magnetic separation, contact with 15% by weight sodium hydroxide solution according to liquid-solid ratio 3:1, react at 110°C for 1 hour, and then separate solid-liquid to obtain sodium silicate desilication liquid and desiliconized fly ash;

[0061] (2) Mix the desiliconized fly ash obtained in step (1) with quicklime and sodium carbonate according to the weight ratio of 1:0.2:1.10 and sinter at 1150°C for 1 hour to obtain clinker. After grinding the clinker to 80 mesh, The adjusting solution is dissolved at 80°C according to the liquid-solid volume ratio of 4:1 to obtain crude sodium aluminate solution and basic calcium silicate. The XRD pattern of basic calcium silicate is shown in figure 2 , Carry out chemical composition analysis to basic calcium silicate, analysis result is shown in Table 1;

[0062] (3) Add lime milk to the crude sodium aluminate solution obtained in step (2)? Desiliconization to obtain sodium aluminate semen, and then pass carbon dioxide into the sodium aluminate semen for carbon separation to obtain aluminum hydroxide and carbon separation mother liquor mainly composed of sodium carbonate, and roast the obtained aluminum hydroxide at 900°C for 0.5h , to produce alumina products; evaporate the mother liquor of carbon fraction at 110°C for 2 hours, and then reuse it in step (2);

[0063] (4) Add the basic calcium silicate obtained in step (2) to the desiliconization solution obtained in step (1), and add milk of lime in such an amount that the molar ratio of calcium to silicon after adding milk of lime is 1:0.8, react at 70°C for 1 hour for combined caustic dealkalization, solid-liquid separation to obtain tobermorite and sodium hydroxide solution, and reuse the obtained sodium hydroxide solution in step (1), tobermorite The XRD chart sees image 3 , to analyze the chemical composition of the tobermorite, and the analysis results are shown in Table 2;

[0064] (5) Add the tobermorite obtained in step (4) to 10% by volume of hydrochloric acid, the molar ratio of hydrochloric acid to tobermorite is 1.8:1, and react at 75°C for 1.0h to obtain silica gel and chloride Calcium solution, after solid-liquid separation, dry the silica gel at 105°C for 1.0h to obtain white carbon black, the XRD pattern of white carbon black is shown in Figure 4 , the chemical composition analysis of white carbon black, the analysis results are shown in Table 3; the chemical composition analysis of the calcium chloride solution, the analysis results are shown in Table 4, the calcium chloride solution was evaporated at 120 ° C for 2.0 h, and then dehydrated at 260 ° C After 0.5h, anhydrous calcium chloride was obtained.

Example Embodiment

[0065] Example 2

[0066] This example is used to illustrate the method for the separation and utilization of aluminum and silicon in fly ash of the present invention.

[0067] (1) Grind fly ash to 200 mesh, remove iron by magnetic separation, contact with 10% by weight sodium hydroxide solution according to the liquid-solid ratio of 4:1, react at 90°C for 2 hours, and then separate solid-liquid to obtain sodium silicate desilication liquid and desiliconized fly ash;

[0068] (2) Mix the desiliconized fly ash obtained in step (1) with quicklime and sodium carbonate according to the weight ratio of 1:0.25:1.20 and sinter at 950°C for 2 hours to obtain clinker. After the clinker is ground to 50 mesh, The adjusting solution was dissolved at 70°C according to the liquid-solid volume ratio of 3:1 to obtain the crude sodium aluminate solution and basic calcium silicate. The XRD pattern of basic calcium silicate and figure 2 Similar, not listed, the chemical composition analysis of basic calcium silicate is carried out, and the analysis results are shown in Table 1;

[0069] (3) The sodium aluminate crude liquid obtained in step (2) is subjected to two steps? Desiliconization to obtain sodium aluminate semen, and then pass carbon dioxide into the sodium aluminate semen for carbon separation to obtain aluminum hydroxide and carbon separation mother liquor mainly composed of sodium carbonate, and roast the obtained aluminum hydroxide at 1000°C for 0.5h , to produce alumina products; evaporate the mother liquor of carbon fraction at 130°C for 1.0h, and then reuse it in step (2);

[0070] (4) Add the basic calcium silicate obtained in step (2) to the desiliconization solution obtained in step (1), and add milk of lime in such an amount that the molar ratio of calcium to silicon after adding milk of lime is 1:1.0, react at 65°C for 2 hours for combined caustic dealkalization, solid-liquid separation to obtain tobernaite and sodium hydroxide solution, and reuse the obtained sodium hydroxide solution in step (1), tobermorite The XRD pattern of image 3 Similar, not listed, the chemical composition of tobermorite was analyzed, and the analysis results are shown in Table 2;

[0071] (5) Add the tobermorite obtained in step (4) to 15% by volume of hydrochloric acid, the molar ratio of hydrochloric acid to tobermorite is 2.0:1, and react at 85°C for 1.0h to obtain silica gel and chloride Calcium solution, after solid-liquid separation, dry the silica gel at 140 ° C for 2 hours to obtain white carbon black, the XRD pattern of white carbon black and Figure 4 Similar, not listed, the chemical composition analysis of white carbon black, the analysis results are shown in Table 3; the chemical composition analysis of the calcium chloride solution, the analysis results are shown in Table 4, the calcium chloride solution was evaporated at 150 ° C for 1.0h, and then Dehydrate at 280°C for 0.5h to obtain anhydrous calcium chloride.

Example Embodiment

[0072] Example 3

[0073] This example is used to illustrate the method for the separation and utilization of aluminum and silicon in fly ash of the present invention.

[0074] (1) Grind the fly ash to 300 mesh, and after removing iron by magnetic separation, contact with 20% by weight sodium hydroxide solution according to the liquid-solid ratio of 5:1, react at 140°C for 0.5h, and then separate the solid and liquid to obtain the sodium silicate Silicon liquid and desiliconized fly ash;

[0075] (2) Mix the desiliconized fly ash obtained in step (1) with quicklime and sodium carbonate at a weight ratio of 1:0.30:1.20 and sinter at 1250°C for 0.5h to obtain clinker, which is ground to 100 mesh, The adjusted solution was dissolved at 90°C according to the liquid-solid volume ratio of 6:1 to obtain crude sodium aluminate solution and basic calcium silicate. The XRD pattern of basic calcium silicate and figure 2 Similar, not listed, the chemical composition analysis of basic calcium silicate is carried out, and the analysis results are shown in Table 1;

[0076] (3) The sodium aluminate crude liquid obtained in step (2) is subjected to two steps? Desiliconization to obtain sodium aluminate semen, and then pass carbon dioxide into the sodium aluminate semen for carbon separation to obtain aluminum hydroxide and carbon separation mother liquor mainly composed of sodium carbonate, and roast the obtained aluminum hydroxide at 950°C for 1.0h , to produce alumina products; evaporate the mother liquor of carbon fraction at 140°C for 1.0h, and then reuse it in step (2);

[0077] (4) Add the basic calcium silicate obtained in step (2) to the desiliconization solution obtained in step (1), and add milk of lime in such an amount that the molar ratio of calcium to silicon after adding milk of lime is 1:1.3, react at 95°C for 0.5h for combined caustic dealkalization, solid-liquid separation to obtain tobermorite and sodium hydroxide solution, and reuse the obtained sodium hydroxide solution in step (1), tobernate calcium The XRD pattern of the stone and image 3 Similar, not listed, the chemical composition of tobermorite was analyzed, and the analysis results are shown in Table 2;

[0078] (5) Add the tobermorite obtained in step (4) to 5% by volume of hydrochloric acid, the molar ratio of hydrochloric acid to tobermorite is 2.2:1, and react at 95°C for 1.5h to obtain silica gel and chloride Calcium solution, after solid-liquid separation, dry the silica gel at 150°C for 1.0h to obtain white carbon black, the XRD pattern of white carbon black and Figure 4 Similar, not listed, the chemical composition analysis of white carbon black, the analysis results are shown in Table 3; the chemical composition analysis of the calcium chloride solution, the analysis results are shown in Table 4, the calcium chloride solution was evaporated at 150 ° C for 1.0h, and then Dehydrate at 260°C for 1.0h to obtain anhydrous calcium chloride.

[0079] Table 1 (unit: mass %)

[0080]

[0081] Table 2 (unit: mass %)

[0082]

[0083] Table 3 (unit: mass %)

[0084]

[0085] Table 4

[0086]

[0087] from figure 2 It can be seen from Table 1 that the main component of basic calcium silicate is sodium calcium silicate, and a small amount of calcite phase exists.

[0088] from image 3And it can be seen from Table 2 that the main components of tobermorite are silica and calcium oxide.

[0089] from Figure 4 It can be seen that relatively broad diffraction peaks appear in the region of 22-35 °, indicating that there is amorphous silicon dioxide to exist. As can be seen from Table 3, the purity of the white carbon black obtained by the inventive method can reach 99%. above.

[0090] The method for separating and utilizing fly ash, aluminum and silicon provided by the invention can obtain white carbon black and anhydrous calcium chloride by-products while extracting aluminum, and the purity of white carbon black can reach more than 99%. The method of the invention greatly improves the added value of aluminum extraction from fly ash.

PUM

Description & Claims & Application Information

We can also present the details of the Description, Claims and Application information to help users get a comprehensive understanding of the technical details of the patent, such as background art, summary of invention, brief description of drawings, description of embodiments, and other original content. On the other hand, users can also determine the specific scope of protection of the technology through the list of claims; as well as understand the changes in the life cycle of the technology with the presentation of the patent timeline. Login to view more.

Classification and recommendation of technical efficacy words

Increase added value

Method for separation and utilization of fly ash aluminum-silicon, and tobermorite and silicon oxide obtained through method

AI-Extracted Technical Summary

Problems solved by technology

Abstract

Image

Examples

Example Embodiment

Example Embodiment

Example Embodiment

PUM

Description & Claims & Application Information

Similar technology patents

Method for extracting pigment and pectin from pineapple peels

Crape myrtle pavilion modeling method

Method for preparing single-piece talcum powder

Tobermorite and synthetic method thereof

High-intensity moisture permeable warp knitting layered mesh cloth based on mixed chemical fiber

Classification and recommendation of technical efficacy words

Production method of plant straw partical board containing absorption purifying agent

Preparation of crust oligosaccharide and use

Method for producing low-melting-point renewable polyester for sheath-core polyester through glycol degradation

Bast fiber fabric with protective function and preparation method thereof

Method for preparing almond peptide from almond dregs