Method for preparing cementing material from electrolytic manganese dioxide waste residues

Abstract

The invention discloses a method for preparing a cementing material by using electrolytic manganese dioxide waste residues, which comprises the following steps: adding CaO with the mass percent of 5% into the electrolytic manganese dioxide waste residues, calcining at 402 + / -3 DEG C for 1-2 hours, and ball-milling the calcined electrolytic manganese dioxide waste residues until the particle size is less than or equal to 38m and the specific surface area is more than or equal to 450m / kg; the fineness and the specific surface area of the electrolytic manganese dioxide waste residues are effectively improved, so that the electrolytic manganese dioxide waste residues are more easily mixed with other materials and have a chemical reaction, the resource utilization rate and the high-value utilization rate of the waste residues are improved, and the prepared electrolytic manganese dioxide residue-based cementing material has excellent mechanical properties and durability.

Description

Technical Field

[0001] This invention relates to the field of electrolytic manganese dioxide technology, and more specifically to a method for preparing cementitious materials using electrolytic manganese dioxide waste residue. Background Technology

[0002] Electrolytic manganese dioxide residue is the acid leaching and pressure filter residue produced during the electrolytic manganese dioxide production process. Its chemical composition is complex, containing not only SiO2, Al2O3, and Fe2O3, but also fluorides and metallic components such as Mn, Cd, Cu, Ni, and Pb.

[0003] In response to the ecological and environmental problems caused by electrolytic manganese dioxide waste residue, how to properly handle and dispose of it has become a key focus of the industry. Among these, the resource-based treatment of electrolytic manganese dioxide waste residue is a particularly hot research topic. Some institutions or units have conducted a lot of related research on the resource-based treatment and utilization of electrolytic manganese dioxide waste residue, such as using manganese slag to produce complete fertilizer. However, these treatment methods either consume too little (small addition ratio) or are not technically mature, so they are rarely used by enterprises or society and are difficult to promote and apply. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing cementitious materials using electrolytic manganese dioxide waste residue, so as to solve the problems existing in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing electrolytic manganese dioxide slag-based cementitious material, comprising the following steps: (1) adding 5% by mass of CaO to electrolytic manganese dioxide waste slag, calcining at 402±3℃ for 1-2 hours, and ball milling the calcined electrolytic manganese dioxide waste slag to a particle size ≤38µm and a specific surface area ≥450 m². 2 / kg; (2) Add Ca(H2PO4)2 to the ball-milled electrolytic manganese dioxide waste residue and mix for 3 min, then add slag, cement clinker, NaOH, and water glass and mix for 3 min. The mass percentage of electrolytic manganese dioxide waste residue, slag, cement clinker, Ca(H2PO4)2, NaOH, and water glass is ≤20%. 55-60%, 20-25%, 2%, 2%, 3%, water glass modulus 1.8-2.0; (3) Add 0.2% sodium tripolyphosphate aqueous solution at a water-to-gel ratio of 1:0.38-0.4 and stir for 5 minutes; (4) After pouring, perform standard curing for 28 days at 25±1℃ and humidity ≥95%.

[0006] As a preferred option, the electrolytic manganese dioxide waste residue after calcination in step (1) is first washed with hot water at 60°C, dried, and then ball-milled. The liquid-solid ratio of the hot water to the electrolytic manganese dioxide waste residue is 3:1.

[0007] Preferably, the exhaust gas after calcination in step (1) is treated by a spray tower and activated carbon adsorption.

[0008] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention realizes the high-value utilization of electrolytic manganese dioxide waste residue, transforming waste into valuable resources and solving the problems of storage space occupation and leakage pollution.

[0009] 2. The electrolytic manganese dioxide slag-based cementitious material prepared by this invention has excellent mechanical properties and durability, and can be widely used in the field of civil engineering to replace traditional cementitious materials and reduce production costs.

[0010] 3. This invention effectively improves the fineness and specific surface area of ​​electrolytic manganese dioxide waste residue, making it easier to mix with other materials and undergo chemical reactions, thereby improving the resource utilization rate of the waste residue. Detailed Implementation

[0011] The technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0012] Example 1: A method for preparing an electrolytic manganese dioxide slag-based cementitious material, comprising the following steps: (1) Adding 5% CaO by mass to the electrolytic manganese dioxide waste residue, i.e., the amount of CaO added is 5% of the amount used for the electrolytic manganese dioxide waste residue, calcining at 405℃ for 1 hour, and treating the tail gas after calcination by spraying tower and activated carbon adsorption. The tail gas is mainly the gas produced by decomposing ammonia nitrogen compounds. The calcined electrolytic manganese dioxide waste residue is first washed with hot water at 60℃, dried, and then ball-milled. The liquid-solid ratio of hot water to electrolytic manganese dioxide waste residue is 3:1. The electrolytic manganese dioxide waste residue is ball-milled to a particle size of 36µm and a specific surface area of ​​480 m². 2 / kg; (2) Add Ca(H2PO4)2 to the ball-milled electrolytic manganese dioxide waste residue and mix for 3 min, then add slag, cement clinker, NaOH, and water glass and mix for 3 min. The mass percentage of electrolytic manganese dioxide waste residue, slag, cement clinker, Ca(H2PO4)2, NaOH, and water glass is 15%. 55%, 25%, 2%, 2%, 3%, water glass modulus 2.0, the above percentages are the percentages of the component in the total mixture; (3) Add an aqueous solution containing 0.2% sodium tripolyphosphate at a water-to-gel ratio of 1:0.4 and stir for 5 minutes, the percentage is the percentage of sodium tripolyphosphate in the mass of the aqueous solution; (4) After pouring, perform standard curing for 28 days at 24℃ and 98% humidity.

[0013] Example 2: A method for preparing an electrolytic manganese dioxide slag-based cementitious material, comprising the following steps: (1) Adding 5% CaO by mass to the electrolytic manganese dioxide waste residue, i.e., the amount of CaO added is 5% of the amount used for the electrolytic manganese dioxide waste residue, calcining at 399°C for 2 hours, and treating the tail gas after calcination by spraying tower and activated carbon adsorption. The tail gas is mainly the gas produced by decomposing ammonia nitrogen compounds. The calcined electrolytic manganese dioxide waste residue is first washed with hot water at 60°C, dried, and then ball-milled. The liquid-solid ratio of hot water to electrolytic manganese dioxide waste residue is 3:1. The electrolytic manganese dioxide waste residue is ball-milled to a particle size of 38µm and a specific surface area of ​​450 m². 2 / kg; (2) Add Ca(H2PO4)2 to the ball-milled electrolytic manganese dioxide waste residue and mix for 3 min, then add slag, cement clinker, NaOH, and water glass and mix for 3 min. The mass percentage of electrolytic manganese dioxide waste residue, slag, cement clinker, Ca(H2PO4)2, NaOH, and water glass is 20%. 60%, 20%, 2%, 2%, 3%, water glass modulus 1.8, the above percentages are the percentages of the component in the total mixture; (3) add 0.2% sodium tripolyphosphate aqueous solution at a water-to-gel ratio of 1:0.38 and stir for 5 minutes, the percentage is the percentage of sodium tripolyphosphate in the mass of the aqueous solution; (4) after pouring, perform standard curing for 28 days at 26℃ and 95% humidity.

[0014] Example 3: A method for preparing an electrolytic manganese dioxide slag-based cementitious material, comprising the following steps: (1) Adding 5% CaO by mass to the electrolytic manganese dioxide waste residue, i.e., the amount of CaO added is 5% of the amount used for the electrolytic manganese dioxide waste residue, calcining at 400℃ for 1.3 hours, and treating the tail gas after calcination by spraying tower and activated carbon adsorption. The tail gas is mainly the gas produced by decomposing ammonia nitrogen compounds. The calcined electrolytic manganese dioxide waste residue is first washed with hot water at 60℃, dried, and then ball-milled. The liquid-solid ratio of hot water to electrolytic manganese dioxide waste residue is 3:1. The electrolytic manganese dioxide waste residue is ball-milled to a particle size of 30µm and a specific surface area of ​​490m². 2 / kg; (2) Add Ca(H2PO4)2 to the ball-milled electrolytic manganese dioxide waste residue and mix for 3 min, then add slag, cement clinker, NaOH, and water glass and mix for 3 min. The mass percentage of electrolytic manganese dioxide waste residue, slag, cement clinker, Ca(H2PO4)2, NaOH, and water glass is 18%. 58%, 23%, 2%, 2%, 3%, water glass modulus 1.8, the above percentages are the percentages of the component in the total mixture; (3) Add an aqueous solution containing 0.2% sodium tripolyphosphate at a water-to-gel ratio of 1:0.4 and stir for 5 minutes, the percentage is the percentage of sodium tripolyphosphate in the mass of the aqueous solution; (4) After pouring, perform standard curing for 28 days at 25℃ and 96% humidity.

[0015] Example 4: A method for preparing an electrolytic manganese dioxide slag-based cementitious material, comprising the following steps: (1) Adding 5% CaO by mass to the electrolytic manganese dioxide waste residue, i.e., the amount of CaO added is 5% of the amount used for the electrolytic manganese dioxide waste residue, calcining at 402℃ for 1.1 hours, and treating the tail gas after calcination by spraying tower and activated carbon adsorption. The tail gas is mainly the gas produced by decomposing ammonia nitrogen compounds. The calcined electrolytic manganese dioxide waste residue is first washed with hot water at 60℃, dried, and then ball-milled. The liquid-solid ratio of hot water to electrolytic manganese dioxide waste residue is 3:1. The electrolytic manganese dioxide waste residue is ball-milled to a particle size of 33µm and a specific surface area of ​​460m². 2 / kg; (2) Add Ca(H2PO4)2 to the ball-milled electrolytic manganese dioxide waste residue and mix for 3 min, then add slag, cement clinker, NaOH, and water glass and mix for 3 min. The mass percentage of electrolytic manganese dioxide waste residue, slag, cement clinker, Ca(H2PO4)2, NaOH, and water glass is 16%. 55%, 25%, 2%, 2%, 3%, water glass modulus 2.0, the above percentages are the percentages of the component in the total mixture; (3) Add an aqueous solution containing 0.2% sodium tripolyphosphate at a water-to-gel ratio of 1:0.38 and stir for 5 minutes, the percentage is the percentage of sodium tripolyphosphate in the mass of the aqueous solution; (4) After pouring, perform standard curing for 28 days at 25℃ and 97% humidity.

[0016] The final products of the above embodiments were subjected to compression and flexural strength tests using the ISO 679 standard. The results are as follows:

[0017] The leaching toxicity test was conducted using the HJ / T 299 sulfuric acid-nitric acid method, which conforms to GB5085.3-2007. The results are as follows:

[0018] The drying shrinkage rate test results are as follows:

[0019] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing cementitious materials using electrolytic manganese dioxide waste residue, characterized in that, Includes the following steps: (1) Add 5% CaO by mass to the electrolytic manganese dioxide waste residue and calcine it at 402±3℃ for 1-2 hours. After calcination, the electrolytic manganese dioxide waste residue is ball-milled to a particle size ≤38µm and a specific surface area ≥450 m² / kg. (2) Add Ca(H2PO4)2 to the ball-milled electrolytic manganese dioxide waste residue and mix for 3 min. Then add slag, cement clinker, NaOH and water glass and mix for 3 min. The mass percentages of electrolytic manganese dioxide waste residue, slag, cement clinker, Ca(H2PO4)2, NaOH and water glass are ≤20%, 55-60%, 20-25%, 2%, 2% and 3%, respectively. The modulus of water glass is 1.8-2.

0. (3) Add an aqueous solution containing 0.2% sodium tripolyphosphate at a water-to-gel ratio of 1:0.38-0.4 and stir for 5 minutes; (4) After pouring, the mixture shall be cured for 28 days under standard conditions at 25±1℃ and humidity ≥95%.

2. The method according to claim 1, characterized in that: Step (1) The calcined electrolytic manganese dioxide waste residue is first washed with hot water at 60℃, dried and then ball-milled. The liquid-solid ratio of hot water to electrolytic manganese dioxide waste residue is 3:

1.

3. The method according to claim 1, characterized in that: Step (1) The exhaust gas after calcination is treated by a spray tower and activated carbon adsorption.

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