CN1260135C

CN1260135C - Method for rapid preparing ferrate solution

Info

Publication number: CN1260135C
Application number: CN 200310103164
Authority: CN
Inventors: 李党生
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-11-06
Filing date: 2003-11-06
Publication date: 2006-06-21
Anticipated expiration: 2023-11-06
Also published as: CN1613778A

Abstract

The present invention discloses a novel method for preparing a ferric acid salt solution, which takes Fe2O3 as reaction iron. A strong alkali solution and Fe2O3 powder are added to a reactor to be boiled for 1 minute to 2 minutes; a NaClO solution is added to be oxidized for 1 minute to 20 minutes at normal pressure and the temperature of 20 to 70 DEG C; the ferric acid salt solution can be obtained by centrifugation or filtration. The method has the advantages of simple technology, available raw material, low alkali consumption, high reaction speed and no pollution. Residues can be circularly utilized, the cost is low, and the stability of the solution is high. The method can be used for preparing the ferric acid salt solution in situ, wherein the ferric acid salt solution serves as a product to be sold, can also serve as anterior segment procedure of a two step method for preparing K2FeO4, BaFeO4, etc. and can also provide supports for teaching research.

Description

Method for rapidly preparing ferrate solution

Technical Field

The invention relates to a preparation method of a compound, in particular to a method for rapidly preparing a ferrate solution.

Technical Field

Ferrate is a high-efficiency multifunctional water treatment agent integrating disinfection, oxidation and coagulation adsorption into a whole and having no toxic or side effect, and is usually potassium ferrate and sodium ferrate, wherein iron is hexavalent and has strong oxidability. Ferrate can release a large amount of atomic oxygen when dissolved in water, thereby killing germs and viruses in the water very effectively, and simultaneously, the ferrate is reduced into nascent state ferric hydroxide per se, and can remove fine suspended matters in the water efficiently. Experiments prove that the disinfection and decontamination effects of ferrate are comprehensively superior to those of chlorine-containing disinfectants and permanganate due to the strong combined action of oxidation and flocculation. More importantly, the water disinfection and purification device does not generate any substance harmful to human bodies in the whole process of disinfecting and purifying water.

Because of the special chemical property of ferrate, the ferrate has high application value in the water treatment process. However, due to poor stability and immature preparation technology, no industrial production application exists so far. In recent years, many universities and scientific research institutions at home and abroad have been in research on preparation, application and development of ferrate, but most of the ferrate is in the laboratory preparation stage, and no ferrate product is on the market at home and abroad.

The key to the applicationof ferrate as a water treatment agent is the synthesis of a stable product. The preparation method can be divided into three types: wet chemical methods, dry chemical methods and electrochemical methods. The chemical dry method is formed by utilizing a solid-phase reaction of an iron compound and potassium nitrate or potassium peroxide, the reaction needs high temperature, the condition is difficult to control, the product is not uniform enough, and the production rate is low; the electrochemical method is to directly carry out anodic oxidation on metallic iron or oxides thereof to obtain hexavalent chromium, and the method is simple to operate, but the current efficiency is reduced due to electrode side reaction, the reactive power consumption is large, and actual production cannot be carried out at present; the chemical wet method is to oxidize ferric iron (salt) into hexavalent chromium by using hypochlorite, and the method has the advantages of complex operation process, strict reaction conditions, complex process, high cost and easy environmental pollution.

Some experts who have recently been working on this aspect for a long time have proposed that ferrate-containing solutions can be used directly as water purifying and oxidizing agents. The efficiency research of direct wastewater treatment by the method or pollution removal by the ferrate compound medicament by some researchers has obvious effect, and the research is increasing day by day. However, in contrast to the current research on water treatment with ferrate in China, the technology for preparing ferrate is not really mature.

The prior art mainly includes the following documents related to the preparation technology and the application of ferrate: ferrate on-site preparation process and system, patent application number: 01106769.1, respectively; tianbazhen, Qujuhui: test of the possibility of cyclic production of potassium ferrate by chemical method, environmental chemistry, 1999, 18 (2): 173-; songhua, Wangbaohui: green synthesis of oxidant ferrate, chemical notification, 2003(4) 242-; ginger spring, wangcong, etc.: a clean production process for preparing potassium ferrate by a chemical oxidation method, which is modern chemical engineering, 2001, 21 (6): 31-34; majun et al, research on pollution removal efficacy of ferrate complex reagent, water supply and drainage, 1998, 24 (2): 21-24; jiahandong et al, research on deodorizing effect of ferrate solution, environmental pollution and prevention 2002, 24 (2): 82-84; renaliling et al, research on ammonia nitrogen removal from coking wastewater by composite ferrate, water treatment technology, 2002, 28 (6): 360-362.

The chemical wet process preparation in the above documents almost all uses iron salt (ferric chloride or ferric nitrate) as iron raw material (ferric hydroxide or ferrous sulfate as raw material respectively), and the conversion of Fe (III) to Fe (VI) usually takes 20-30 minutes.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a quick and cheap preparation method of ferrate.

The invention adopts the following technical scheme.

The invention aims to obtain cheap and easily-obtained iron oxide (Fe)₂O₃) As raw materials, under the conditions of reducing alkali consumption and changing heating conditions, the time for obtaining a solution with similar concentration is only a few minutes. The preparation reaction principle is as follows:

the preparation method comprises the following steps:

a. adding strong base NaOH solution into the reactor andsimultaneously adding Fe₂O₃Powder with the mol ratio of 4-7: 1, boiling for 1-2 minutes;

b. adding NaClO solution with effective chlorine not less than 10%, NaClO solution and Fe₂O₃The weight ratio of the two is controlled to be 1-10: 1, the oxidation is carried out for 1-20 minutes under the conditions of normal pressure and 20-70 ℃, and the mixture is fully stirred;

c. the ferrate solution can be obtained by centrifugation or filtration.

The strong base NaOH may be replaced by KOH.

As a preferred embodiment of the present invention, an auxiliary agent Na may be added to the resulting ferrate solution₂SiO₃In an amount of Fe₂O₃2-5% by weight. The obtained ferrate solution can be used at normal temperatureTo be stored for more than 1 month.

The method can be used for preparing ferrate solution on site, and the prepared solution can be sold as a product; also can be used as a two-step method for preparing K₂FeO₄、BaFeO₄The former stage and the latter stage are carried out according to the prior art; the method can provide good support for the research of the properties and the application of the product, and can also be used as teaching experiment contents.

The invention has the advantages that:

1. the method overcomes the defects of complex preparation process, poor solution stability and the like of the prior ferrate, has high reaction speed which is more than 10 times of that of the prior art, realizes the existing preparation, and makes the direct application and production of the ferrate solution possible;

2. the reactive iron being Fe₂O₃The excessive NO introduced by the traditional process (ferric chloride or ferric nitrate is used as reaction iron) is reduced₃ ^-Or Cl^-The product has no harmful ions and no pollution, the residue can be recycled, and a more complex process when ferric hydroxide and ferrous sulfate are used as reaction iron is also avoided;

3. the raw materials are easy to obtain, the alkali consumption is low, the reaction is carried out according to the reaction principle of 4/10 in the traditional process under the normal pressure condition, the energy is saved, and the cost is low.

Detailed Description

Example 1

9.6g of Fe were weighed₂O₃Putting the mixture into 40ml of 30% NaOH solution, boiling for 1 minute, adding 20ml of NaClO solution with the available chlorine of 10%, stirring properly under normal pressure, controlling the temperature to be about 70 ℃, reacting for 1-2 min, and centrifuging to obtain the ferrate solution with the concentration of about 1.8 g/L. Adding 0.2g Na into the prepared ferrate solution₂SiO₃. The concentration can be rapidly measured when the reagent is used.

Example 2

9.6g of Fe were weighed₂O₃Putting the mixture into 40ml of 40% NaOH solution, boiling for 2 minutes, adding 20ml of NaClO solution with 15% of available chlorine, stirring properly under normal pressure, controlling the temperature to be about 35 ℃, reacting for 2-3 min, and filtering to obtain the ferrate solution with the concentration of about 2.5 g/L. Adding O.3gNa into the prepared ferrate solution₂SiO₃。

Example 3

9.6g of Fe were weighed₂O₃Puttingthe mixture into 40ml of 30% KOH solution, boiling for 1 minute, adding 25ml of NaClO solution with the available chlorine of 10%, stirring properly under normal pressure, controlling the temperature to be about 60 ℃, reacting for 1-2 min, and centrifuging to obtain the ferrate solution with the concentration of about 2.8 g/L. Adding O.4gNa into the prepared ferrate solution₂SiO₃。

Claims

1. A method of preparing a ferrate solution, comprising the steps of:

a. adding a strong alkaline solution into the reactor and simultaneously adding Fe₂O₃Powder with the mol ratio of 4-7: 1, boiling for 1-2 minutes;

b. adding NaClO solution with effective chlorine not less than 10%, NaClO solution and Fe₂O₃The weight ratio of the two is controlled to be 1-10: 1, the oxidation is carried out for 1-20 minutes under the conditions of normal pressure and 20-70 ℃,fully stirring at the same time;

c. obtaining ferrate solution by centrifugation or filtration;

wherein, the strong base is NaOH or KOH.

2. The method of claim 1, wherein an additive Na is added to the ferrate solution produced₂SiO₃In an amount of Fe₂O₃2-5% by weight.