阅读说明：本技术 一种净水型免烧陶粒及制备方法 (Water purification type baking-free ceramsite and preparation method thereof ) 是由 张宁 吴海滨 宋慧平 冯政君 李剑锋 程芳琴 于 2020-06-17 设计创作，主要内容包括：本发明涉及净水技术领域,更具体而言,涉及一种净水型免烧陶粒及制备方法；由原料粉煤灰、淀粉、氧化钙、脱硫石膏、过硼酸钠加水造粒制得,同时负载和嵌入碳基催化剂、金属氧化物,工艺简单,制备过程不需要进行高温煅烧,节能环保；独有的高效发泡过程可以在固相状态下在陶粒内部及表面造孔,使得得到的陶粒产品具有高孔隙率,可有效地实现保水保肥,也降低了陶粒的堆积密度；发泡剂过硼酸钠分解后残留的硼酸钠可作为植物提供硼等微量元素；材料中包含的淀粉可以提高材料的微生物亲和性,在环境中降解后也可以释放出少量的孔隙,提高材料的孔隙率；陶粒负载和嵌入碳基催化剂、金属氧化物,对城市地表径流具备净化功能。(The invention relates to the technical field of water purification, in particular to water purification type baking-free ceramsite and a preparation method thereof; the catalyst is prepared by adding water into raw materials of fly ash, starch, calcium oxide, desulfurized gypsum and sodium perborate for granulation, and simultaneously loading and embedding a carbon-based catalyst and a metal oxide, so that the process is simple, high-temperature calcination is not required in the preparation process, and the catalyst is energy-saving and environment-friendly; the unique efficient foaming process can form holes in the inside and on the surface of the ceramsite in a solid phase state, so that the obtained ceramsite product has high porosity, can effectively realize water and fertilizer conservation, and also reduces the stacking density of the ceramsite; residual sodium borate after decomposition of the foaming agent sodium perborate can be used as a plant to provide trace elements such as boron and the like; the starch contained in the material can improve the microbial affinity of the material, and can release a small amount of pores after being degraded in the environment, so that the porosity of the material is improved; the ceramsite is loaded and embedded with a carbon-based catalyst and a metal oxide, and has a purification function on urban surface runoff.)

1. The preparation method of the water purification type baking-free ceramsite is characterized by comprising the following steps of:

s1, weighing 30-75 parts of fly ash, 10-35 parts of starch, 10-40 parts of calcium oxide, 1-2 parts of desulfurized gypsum and 5-20 parts of sodium perborate according to parts by weight, and uniformly mixing to obtain a mixed material;

s2, putting the mixed material in the S1 into a disc granulator, and spraying 30-50 parts by weight of water into the granulator at a flow rate of 1-5 parts per minute to obtain ceramsite green pellets;

s3, sieving the ceramsite green pellets in the S2 to obtain ceramsite green pellets with the particle size of 8-20 mm;

s4, placing the ceramsite green pellets in the step S3 into a steam curing device for curing, wherein the air humidity in the curing device is more than 70%, and the curing temperature program is as follows: curing at 40-70 ℃ for 0.5-2h, then curing at 70-100 ℃ for 2-4h, then oxidizing at 150-;

s5, taking a certain amount of reduced graphene oxide powder, dissolving the reduced graphene oxide powder in deionized water, and performing ultrasonic oscillation for 60min to obtain 1g/L reduced graphene oxide aqueous solution;

s6, dropping 12ml tetrabutyl titanate into 48ml absolute ethyl alcohol under stirring, adding a certain amount of inhibitor, continuing stirring and dropwise adding 4ml H₂O to obtain a solution A;

s7, slowly dripping the solution A prepared in the S6 into the reduced graphene oxide aqueous solution, and stirring until the solution becomes sol;

s8, washing the solid-phase foaming fly ash unfired ceramsite prepared in the S4 with distilled water and ethanol for three times, and then putting the solid-phase foaming fly ash unfired ceramsite into the S7 to dip the solid-phase foaming fly ash unfired ceramsite in the S7 for 1-2 min;

s9, taking out the solid-phase foamed fly ash unfired ceramsite treated by the S8, placing the solid-phase foamed fly ash unfired ceramsite in an oven, and drying the solid-phase foamed fly ash unfired ceramsite for 2 to 4 hours at the temperature of 100 ℃ and 150 ℃;

s10, repeating S8-S93-4 times;

s11, naturally cooling the dried solid-phase foamed fly ash unfired ceramsite, and washing off excessive TiO on the surfaces of carrier particles by deionized water₂Thereby preparing a supported TiO₂And rGO (red graphene oxide) water purification type non-sintered ceramsite.

2. The preparation method of the water purification type baking-free ceramsite according to claim 1, characterized by comprising the following steps: the water temperature in the step S2 is lower than 15 ℃.

3. The preparation method of the water purification type baking-free ceramsite according to claim 1, characterized by comprising the following steps: the rotating speed of the disc granulator is 20-50 r/min, and the inclination angle is 30-50 degrees.

4. The water purification type baking-free ceramsite is characterized by being prepared from the following raw materials in parts by weight: 30-75 parts of fly ash, 10-35 parts of starch, 10-40 parts of calcium oxide, 1-2 parts of desulfurized gypsum, 5-20 parts of sodium perborate and 30-50 parts of water; the water-free type non-fired ceramsite is prepared by loading and embedding a carbon-based catalyst and a metal oxide.

Technical Field

The invention relates to the technical field of water purification, and particularly relates to water purification type baking-free ceramsite and a preparation method thereof.

Background

The ceramsite has rich pores and has the effects of water and fertilizer retention; meanwhile, the culture medium has certain strength and adjustable particle size, and is an excellent horticultural culture medium. However, most of the horticultural ceramsite in the current market is sintered ceramsite, which needs to be calcined at a temperature of over 1000 ℃, so that the horticultural ceramsite has high cost and is not energy-saving and environment-friendly. Therefore, there is a need to develop a non-sintered ceramsite prepared at a low temperature.

The invention with the publication number of CN102701785A discloses a preparation method of fly ash non-sintered ceramsite, which takes fly ash, cement, metal sulfide and the like as main raw materials, and prepares the non-sintered ceramsite after granulation and autoclaved curing, but the method is lack of the process of foaming and pore-forming, and the prepared ceramsite has higher density and undeveloped pores.

The invention patent with publication number CN105060923A discloses a preparation method of light non-fired ceramsite, which uses aluminum powder to foam for pore-forming, but the aluminum powder as a pore-forming agent can generate hydrogen after being fully contacted and reacted with alkali, thereby generating bubbles and forming pores. The ceramsite green ball is solid and contains a small amount of water, but the sufficient contact and reaction between aluminum powder and alkali cannot be guaranteed, so that the foaming and pore-forming effects are poor.

The invention patent with publication number CN108465490A discloses a preparation method of a porous material loaded with nano titanium dioxide, which utilizes nano titanium dioxide and graphene oxide composite aqueous solution as an internal phase of high internal phase emulsion polymerization, and styrene and hydroxyethyl methacrylate are subjected to water-in-oil high internal phase emulsion polymerization to obtain the porous material loaded with nano titanium dioxide on the surface. The method uses organic polymer solution as carrier, and the method and action mechanism are different from the patent.

The invention patent with publication number CN108479415A discloses a graphene oxide composite water treatment membrane and a preparation method thereof, and the membrane has a three-layer composite structure, and is sequentially provided with a high molecular porous material pretreatment layer, a graphene oxide active purification layer and a high molecular porous material supporting layer from top to bottom. The method utilizes a high polymer material as a carrier, and graphene only has adsorption and oxidation functions, which are different from the materials and mechanisms of the method.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention adopts a novel foaming material and technology, and provides the water-purifying type baking-free ceramsite with efficient adsorption, oxidation and catalysis functions and the preparation method thereof.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

a preparation method of water purification type baking-free ceramsite comprises the following steps:

s1, weighing 30-75 parts of fly ash, 10-35 parts of starch, 10-40 parts of calcium oxide, 1-2 parts of desulfurized gypsum and 5-20 parts of sodium perborate according to parts by weight, and uniformly mixing to obtain a mixed material;

s2, putting the mixed material in the S1 into a disc granulator, and spraying 30-50 parts by weight of water into the granulator at a flow rate of 1-5 parts per minute to obtain ceramsite green pellets;

s3, sieving the ceramsite green pellets in the S2 to obtain ceramsite green pellets with the particle size of 8-20 mm;

s4, placing the ceramsite green pellets in the step S3 into a steam curing device for curing, wherein the air humidity in the curing device is more than 70%, and the curing temperature program is as follows: curing at 40-70 ℃ for 0.5-2h, then curing at 70-100 ℃ for 2-4h, then oxidizing at 150-;

s5, taking a certain amount of reduced graphene oxide powder, dissolving the reduced graphene oxide powder in deionized water, and performing ultrasonic oscillation for 60min to obtain 1g/L reduced graphene oxide aqueous solution;

s6, dropping 12ml tetrabutyl titanate into 48ml absolute ethyl alcohol under stirring, adding a certain amount of inhibitor, continuing stirring and dropwise adding 4ml H₂O to obtain a solution A;

s7, slowly dripping the solution A prepared in the S6 into the reduced graphene oxide aqueous solution, and stirring until the solution becomes sol;

s8, washing the solid-phase foaming fly ash unfired ceramsite prepared in the S4 with distilled water and ethanol for three times, and then putting the solid-phase foaming fly ash unfired ceramsite into the S7 to dip the solid-phase foaming fly ash unfired ceramsite in the S7 for 1-2 min;

s9, taking out the solid-phase foamed fly ash unfired ceramsite treated by the S8, placing the solid-phase foamed fly ash unfired ceramsite in an oven, and drying the solid-phase foamed fly ash unfired ceramsite for 2 to 4 hours at the temperature of 100 ℃ and 150 ℃;

s10, repeating S8-S93-4 times;

s11, naturally cooling the dried solid-phase foamed fly ash unfired ceramsite, and washing off excessive TiO on the surfaces of carrier particles by deionized water₂Thereby preparing a supported TiO₂And rGO (red graphene oxide) water purification type non-sintered ceramsite.

Further, the water temperature in the step S2 is lower than 15 ℃.

Further, the rotating speed of the disc granulator is 20-50 revolutions per minute, and the inclination angle is 30-50 degrees.

The water purification type non-sintered ceramsite is prepared from the following raw materials in parts by weight: 30-75 parts of fly ash, 10-35 parts of starch, 10-40 parts of calcium oxide, 1-2 parts of desulfurized gypsum, 5-20 parts of sodium perborate and 30-50 parts of water; the water-free type non-fired ceramsite is prepared by loading and embedding a carbon-based catalyst and a metal oxide.

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

the invention provides a water purification type baking-free ceramsite and a preparation method thereof. Sodium perborate is stable at room temperature, but undergoes decomposition at 40-60 deg.C to produce oxygen and sodium borate, oxygen being inForming air bubbles in the ceramsite, thereby realizing pore forming. The self-decomposition characteristic of the heated sodium perborate ensures the foaming strength and the pore-forming effect. In order to improve the plasticity of the ceramsite and enhance the stability of air bubbles in the ceramsite, a small amount of starch is doped, raw starch is heated in water until the micelle structure is completely collapsed, and starch molecules form single molecules and are surrounded by the water to form a solution state. The starch molecules are chain-shaped or branched and mutually dragged to form a pasty solution with viscosity after being heated, so that a pseudoplastic fluid is formed. The pseudoplastic fluid has no yield stress, has viscosity, and has equivalent plasticity and foam stabilizing capability. Therefore, the starch is added into the raw materials, and the plasticity and the foam stabilizing capability of the material can be obviously improved. In order to prevent the sodium perborate from being decomposed by preheating during the preparation process, the water in the raw materials is required to be cold water and less than 15 ℃. In order to decompose the sodium perborate at a suitable rate, the sodium perborate should be cured at 40-70 deg.C for 0.5-2 h. In order to allow the added starch to be cooked, curing is required for 2-4h at 70-100 ℃. In order to accelerate the hydration of the material, the curing is required to be carried out for 8-12h at the temperature of 150-200 ℃ in a humidity environment of more than 70 percent. The process is simple, high-temperature calcination is not needed in the preparation process, and the preparation method is energy-saving and environment-friendly; the unique efficient foaming process can form holes in the inside and on the surface of the ceramsite in a solid phase state, so that the obtained ceramsite product has high porosity, can effectively realize water and fertilizer conservation, and also reduces the stacking density of the ceramsite; residual sodium borate after decomposition of the foaming agent sodium perborate can be used as a plant to provide trace elements such as boron and the like; the starch contained in the material can improve the microbial affinity of the material, and on the other hand, the starch can release a small amount of pores after being degraded in the environment, so that the porosity of the material is improved; meanwhile, the ceramsite is loaded and embedded with a carbon-based catalyst and a metal oxide, and has a purification function on urban surface runoff by utilizing mechanisms of adsorption, catalysis, oxidation and the like. Can effectively remove SS, COD and NH in urban surface runoff₃-N。

Drawings

FIG. 1 is a schematic view of the microstructure of a water purification type baking-free ceramsite prepared by the invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.