CN101481118B - Method for preparing zeolite molecular sieve from fly ash by using alkali fusion-steaming process - Google Patents

Abstract

The invention discloses a method for preparing zeolite molecular sieve by fly ash through adopting alkaline fusion-steam. The method takes fly ash as a raw material melting with solid sodium hydroxide at a high temperature. The liquid melt and a small amount of steam react for 12 hours inside a reaction kettle, so the zeolite molecular sieve is generated. The method has simple equipment and simple and convenient operation, the fly ash grog refractory does not need to be grinded, and a small amount of steam water (nonsolvent water) is needed to participate in the reaction. Therefore, the production process does not pollute the environment, the range of the reaction temperature is larger, the reaction time is short, and the energy source is saved. The invention is a simple, convenient and feasible method for preparing the zeolite molecular sieve with a microcellular structure, is more particularly suitable for the industrial production in mass, and provides a good application way for the multipurpose use of the fly ash.

Description

Utilization of fly ash alkali fusion-steaming process prepares the method for zeolite molecular sieve

Technical field

The present invention relates to the method for a kind of flyash utilization of waste material (processing), the method for particularly a kind of utilization of fly ash alkali fusion-steam production zeolite molecular sieve.

Background technology

Zeolite is a kind of crystalline aluminosilicate, and silicon wherein, aluminium atom all form silicon-oxy tetrahedron or aluminum-oxygen tetrahedron with Sauerstoffatom, the three-dimensional framework that connects into complexity, opens by shared Sauerstoffatom between the tetrahedron, the duct and the cavity of the rule that distributing in the structure.These ducts and cavity can be in conjunction with the molecules of specific size, and positively charged ion wherein has interchangeability.Therefore, zeolite have very big specific surface area with good absorption, separate, performance such as ion-exchange, catalysis, have purposes widely in fields such as petrochemical complex, environment protection.Multi-field have a good prospects for application, become the new focus in investigation of materials field, hole.Industrial synthesis zeolite is to adopt water glass, sodium aluminate, Al (OH) ₃9H ₂Industrial chemicals such as O, sodium metaaluminate, cost height and complex process.

China's flyash quantity discharged reaches 1.6 hundred million tons, and still increases with annual 1000 ten thousand tons speed, and its utilization ratio also belongs to low-level in China, China to the utilization of coal ash rate only between 30%～40%.At present, the technique means of Comprehensive Utilization Power Plant waste flyash improves constantly, the goods and materials product that utilizes flyash production to help national economy has become the main flow of using flyash, it is mainly used in building brickmaking, cement raw material, roadbed material, soil improvement agent, loading material of rubber etc., and usage quantity far is unable to catch up with the speed that increases newly of annual flyash, flyash still need significantly be developed and go deep into to utilize, especially utilize main chemical compositions wherein, with the high value added product is that the Application and Development that leads is a direction of flyash future development, it also is the hot issue that present insider extremely pays close attention to, for example, utilize flyash to produce cement, the aluminum oxide road that moved towards the industrialization, and utilize flyash to produce white carbon black, technology such as molecular sieve also are in the stage of fumbling of industry.

The composition of the mineral substance of flyash is mainly quartz, mullite, vitreum and a spot of carbon, magnetite etc., and main chemical composition is SiO ₂, Al ₂O ₃, both content are more than 70%.In view of the composition of flyash and the volcanic ash that forms natural zeolite have similarity, 1985, Holler ^[1]Deng the research that utilizes the flyash synthesis zeolite that takes the lead in having carried out, this research has been pointed out a feasible approach for total utilization of PCA and searching synthesis of molecular sieve new raw material, and its achievement in research has just caused extensive concern once announcing.Thereafter, the various countries researchist utilize the different places of production flyash, prepared dissimilar zeolite molecular sieves by different synthetic process.According to the domestic and foreign literature report as can be known, the method for synthetic zeolite mainly contains original position water (solvent) thermal synthesis method ^[2], the hot method of alkali fusion-water (solvent) ^{[3] [4]}, microwave assisting method ^{[5] [6]}, add crystal seed method ^[7]Etc. technology (document sees reference).These methods not only energy consumption big, environment is polluted greatly, and the transformation efficiency of generation zeolite is not high yet.Given this, the flyash synthetic zeolite is difficult to realize industrialization, and majority state also is in the experimental study stage at present.

Reference:

【1】Holler?H，Wirsching?U.Zeolites?formation?from?fly?ash[J].Mineral，1985，63(1)：21-43。

【2】Querol?X，Plana?F，Alastuey?A，et?al.Synthesis?of?Na-zeolites?fromfly?ash[J].Fuel，1997，76(8)：793-799。

【3】Shigemoto?N，Shirakami?S，Hirano?S，et?al.Preparation?andcharacterization?of?zeolites?from?coal?fly?ash[J].Chem?Soc?Jpn，1992，5：484-492。

【4】SingerA，Berkgaut?V.Cation?exchange?p?roperties?of?hydrothermallytreated?coal?fly?ash[J].Environ?Sci?Technol，1995，29(9)：1748-1753。

【5】Querol?X，Alastuey?A，Lopez-SolerA.A?fastmethod?for?recycling?flyash：microwave-assisted?zeolite?synthesis[J].Environ?Sci?Techno，1997，31(9)：2527-2533。

【6】Miki?I，Hidenobu?T，Yukari?E，et?al.Microwave-assisted?zeolitesynthesis?from?coal?fly?ash?in?hydrothermal?p?rocess[J].Fuel，2005，84：1482-1486。

【7】La?Rosa?J?L，Kwan?S，Grutzeck?MW.Zeolite?formation?in?class?FflyAsh?blended?cement?pastes[J].JAm?Ceram?Soc，1992，75(6)：1574-1578。

Summary of the invention

The object of the invention is, the method for a kind of utilization of fly ash alkali fusion-steam production zeolite molecular sieve is provided, and this method is suitable for industrialization flyash is produced zeolite product, also will open up a kind of new approach for the recycling of flyash.

In order to realize above-mentioned task, the present invention takes following technical solution:

1, the method for a kind of utilization of fly ash alkali fusion-steam production zeolite molecular sieve is characterized in that, specifically comprises the steps:

Step 1 is got a certain amount of flyash ball milling;

Step 2 is got a certain amount of NaOH solid, grind the back with etc. the ball milling flyash of quality mix, obtain mixture;

Step 3 with mixture fusion 2 hours～3 hours under 850 ℃ of temperature in retort furnace, generates the flyash grog;

Step 4 is got the flyash grog and is put into the tetrafluoroethylene reactor; And press the flyash grog: water=2: 1 (m/v, g/mL) ratio is got tap water, and tap water joined in the little reagent bottle, should also together put in the tetrafluoroethylene reactor by little reagent bottle, keep water to separate with the flyash grog during placement, the water in the little reagent bottle is used to produce steam;

Step 5 is under room temperature to 200 ℃ even the higher condition with reactor in temperature range, places 12 hours, can generate zeolite molecular sieve.

The temperature of above-mentioned preferred reactor is 100 ℃.

The present invention adopts alkali fusion-steaming process that flyash grog and water vapor are reacted, and the high more speed of response of temperature will be accelerated, and can generate zeolite product (temperature variation does not influence the kind of product); Compare with the present both at home and abroad method of synthetic zeolite, processing unit simple (can with the better various containers of sealing property), the time spent is short, energy consumption is little, be convenient to operation and transformation efficiency is very high and the pollution of having avoided water (solvent) thermal synthesis method to cause a large amount of waters that environment is brought.

Description of drawings

Fig. 1 is a process flow sheet of the present invention;

Fig. 2 is that grog M amplifies 8000 times of SEM figure;

Fig. 3 is that zeolite N amplifies 20000 times of SEM figure;

Fig. 4 is the XRD contrast figure of grog M and zeolite N

The present invention is described in further detail below in conjunction with accompanying drawing.

Embodiment

Referring to Fig. 1, the method according to utilization of fly ash alkali fusion of the present invention-steam production zeolite specifically comprises the steps:

1, get flyash and with XRD and XRF analysis means flyash is analyzed, the chemical ingredients in the flyash mainly is: SiO ₂Account for 54.20%, Al ₂O ₃Account for 26.40%, all the other are other impurity; Its main thing is mullite and quartz mutually;

2, get a certain amount of flyash and grind, then with etc. the NaOH solid (deviation＜20%) that grinds of quality mix, obtain mixture;

3, mixture is placed in the retort furnace, under 850 ℃ of temperature fusion 2-3 hour, generate the flyash grog; This flyash grog is the alkali fusion thing, and outward appearance is the green particles shape, and its is remembered as material M;

4, take by weighing 2g material M, and get 1 little reagent bottle, be added with 1mL tap water (material M and tap water deviation are not more than 0.5g/mL) in the bottle, together putting into the tetrafluoroethylene reactor (notes keeping water and flyash grog not to mix with water during placement, water wherein is used to produce steam, for the absorption of flyash grog);

5, reactor is placed in 100 ℃ of baking ovens under the condition, places and take out reaction product after 12 hours, be designated as product N through washing, separation, oven dry post precipitation;

The thing of measuring flyash grog M and product N with XRD and SEM respectively reaches pattern composition (Fig. 2, Fig. 3) mutually, and visible reaction product N is zeolite molecular sieve (Fig. 4); Can also see the about 1 μ m size of zeolite grain by SEM figure.

Certainly, also reactor can be placed under room temperature to 200 ℃ even the higher condition, place 12 hours, can generate zeolite molecular sieve.The high more speed of response of temperature that experiment showed, through the contriver will be accelerated, and temperature variation does not influence the kind of product.

Claims (1)

1. the method for utilization of fly ash alkali fusion-steam production zeolite molecular sieve is characterized in that, specifically comprises the steps:

Step 1 is got a certain amount of flyash ball milling;

Step 2 is got a certain amount of NaOH solid, grind the back with etc. the ball milling flyash of quality mix, obtain mixture;

Step 3 with mixture fusion 2 hours～3 hours under 850 ℃ of temperature in retort furnace, generates the flyash grog;

Step 4 is got the flyash grog and is put into the tetrafluoroethylene reactor; And in the flyash grog: the ratio of water=2: 1g/mL is got tap water, and tap water joined in the little reagent bottle, should also together put in the tetrafluoroethylene reactor by little reagent bottle, keep water to separate with the flyash grog during placement, the water in the little reagent bottle is used to produce steam;

Step 5 is under 100 ℃ the condition, to place 12 hours in temperature with reactor, can generate zeolite molecular sieve.

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