CN1252316C

CN1252316C - Preparation of antimonic oxychloride by electrochemical sacrificial anode protection method

Info

Publication number: CN1252316C
Application number: CN 200310112650
Authority: CN
Inventors: 顾建胜; 郑波; 童剑英
Original assignee: Suzhou University
Current assignee: Suzhou University
Priority date: 2003-12-11
Filing date: 2003-12-11
Publication date: 2006-04-19
Anticipated expiration: 2023-12-11
Also published as: CN1546732A

Abstract

The present invention relates to a method for preparing antimony oxychloride. The present invention is characterized in that metallic antimony is used as an anode, and an insolubility electric conducting material is used as a cathode; the metallic antimony is dissolved by an electrochemical sacrificial anode method, and the antimony oxychloride (SbOCl and Sb4O5Cl2) is obtained by hydrolyzing an electrolyte. The present invention has the characteristics of normal pressure operation of the whole process, simple processes, convenient operation, easy storage of raw material antimony, cyclic use of a hydrolyzing mother solution, no waste liquid and exhaust gas, environmental pollution elimination and cost reduction, and price is lower than that of pure SbCl3 and Sb2O3.

Description

Electrochemical sacrificial anode method for preparing antimony oxychloride

Technical Field

The invention relates to a method for producing antimony oxychloride (SbOCl, Sb)₄O₅Cl₂) In particular to a method for preparing antimony oxychloride by adopting an electrochemical sacrificial anode method.

Background

Antimony oxychloride is a halogen-and antimony-containing antimony compound, with Sb₂O₃、NaSb(OH)₆Compared with antimony flame retardants containing no halogen, the flame retardant has more excellent flame retardant efficiency, and is widely used for flame retarding of synthetic materials such as thermoplastic polymers, rubber, fibers and the like.

The existing antimony oxychloride preparation methods mainly comprise four methods: (1) antimony trichloride hydrolysis method; (2) antimony trichloride-ethanol process, which involves introducing an equimolar amount of SbCl₃Putting the crystal and absolute ethyl alcohol into a glass tube, sealing, heating to 160 ℃ in a tube furnace for several hours, and then cutting the glass tube to obtain SbOCl crystal, wherein the product is required to be refined; (3) the method comprises the steps of reacting SbCl in a concentrated hydrochloric acid medium at a temperature of 109-110 DEG C₃And Sb₂O₃Heating and refluxing, stirring continuously, obtaining antimony oxychloride product, controlling different hydrochloric acid concentrations and respectively obtaining SbOCl and Sb₄O₅Cl₂(ii) a (4) The hydrogen chloride-antimony trioxide method, in which Sb is added in the presence of concentrated hydrochloric acid₂O₃Introducing HCl gas, heating and refluxing at 100-110 deg.C for about 1 hr, and controlling different hydrochloric acid concentrations and HCl gas amounts to obtain SbOCl and Sb₄O₅Cl₂。

The four methods have the characteristics of SbCl₃And Sb₂O₃As a raw material, SbCl₃The material is extremely easy to deliquesce, strong in corrosivity and difficult to store; pure SbCl₃And Sb₂O₃The price of antimony oxychloride is relatively high, thus seriously hindering the practical application of antimony oxychloride. In addition, the preparation method can generate waste liquid and waste gas, pollute the environment and increase the post-treatment cost.

Aiming at the defects of the prior art, the invention provides a method for preparing a novel anti-cancer medicineThe antimony oxychloride (SbOCl, Sb) is effectively prepared by using metal antimony as a raw material through the operations of electrolysis, hydrolysis, filtration, washing and drying₄O₅Cl₂) The method of (1).

Disclosure of Invention

In order to achieve the purpose, the invention adopts the technical scheme that: the method takes metallic antimony as an anode and insoluble conductive material as a cathode, and respectively operates as follows according to different electrolytes: (1) using hydrochloric acid or acid solution containing chloride salt such as sodium chloride as electrolyte, controlling acidity to be 0.5-6 mol/L, electrolyzing at 40-80 ℃,cathodic evolution of H during electrolysis₂And black active antimony powder Sb^*And (4) generating. After the electrolysis is stopped, the mixture is continuously heated and stirred until the black Sb^*The powder disappeared to give a clear solution. (2) Electrolyzing with sodium chloride solution as electrolyte to discharge H from cathode₂And black active antimony powder Sb^*Generating; white deposits appeared near the anode. After the electrolysis is stopped, hydrochloric acid is added, and the mixture is heated and stirred until the black Sb is obtained^*The powder and white deposit disappeared to give a clear solution. (3) Electrolyzing with sodium hydroxide solution as electrolyte to discharge H from cathode₂And black active antimony powder Sb^*Generating: after the electrolysis is stopped, hydrochloric acid is added, and the mixture is continuously heated and stirred until the black Sb^*The powder disappeared to give a clear solution. The insoluble conductive material is selected from one of the following materials: iron, steel, carbon steel, stainless steel, nickel, titanium, copper, graphite.

Hydrolyzing the obtained transparent solution, and respectively carrying out the following treatments: (1) controlling the acidity C of the solution_H+Less than 2.5mol/L (preferably 0.1-2.4 mol/L), stirring and hydrolyzing at 0-40 ℃, separating out white precipitate, filtering, washing and drying to obtain Sb₄O₅Cl₂Powder; (2) making the solution Sb³⁺The concentration is more than or equal to 300g/L, and the acidity C of the solution is controlled_H+Not less than 2.5mol/L (preferably 2.5-2.7 mol/L), stirring and hydrolyzing at 0-40 ℃ to generate white precipitate, and filtering, washing and drying the white precipitate to obtain the SbOCl.

The main reaction is illustrated by taking the example of electrolysis in an acid solution and then hydrolyzing the electrolyte to prepare antimony oxychloride:

electrolysis: anode:

cathode:

(Black active powder)

Heating and stirring:

hydrolysis:

during electrolysis, part of Sb³⁺Reduced to active black antimony powder (with Sb) at the cathode^*Expressed), is soluble when heated and stirred. The electrolysis temperature is not very important, but too high a temperature can cause volatilization of the solution, and too low a temperature can affect electrolysis and active Sb^*The dissolving speed is controlled to be 40-80 ℃. When the acidity of the electrolyte is high, Sb is favored^*The amount of water added during hydrolysis is increased, and the acidity of 0.5-6 mol/L is selected for electrolysis by combining two factors. The antimony oxychloride is dissolved in hot water, so that the hydrolysis temperature is controlled to be 0-40 ℃.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:

1. the whole process is normal pressure operation, the process is simple, and the operation is convenient;

2. the raw material antimony is easy to store and the price is lower than that of pure SbCl₃And Sb₂O₃：

3. The hydrolysis mother liquor can be recycled, basically no waste liquor and waste gas are generated, the pollution to the environment is eliminated, and the cost is reduced.

Drawings

FIG. 1 shows Sb obtained by the present invention₄O₅Cl₂The process flow diagram of (1);

FIG. 2 is a flow chart of the process for obtaining SbOCl according to the present invention.

Detailed Description

The invention is further described with reference to the following figures and examples:

the first embodiment is as follows: referring to the attached figure 1, 1.2g of sodium chloride, 26.0mL of concentrated hydrochloric acid and 40.0mL of water are taken and put into a single-chamber reactor with a metal Sb block as an anode and a Ti sheet as a cathode. The direct current is supplied, the voltage is 2V, the current is 300mA, and the cathode current density is 1300A/m²Electrolyzing at 60 deg.C for 2 hr to discharge H from cathode₂And has black active Sb^*And (5) powder generation. After the electrolysis is finished, taking out the electrode, and continuing heating and stirring until the electrode is black Sb^*And (4) removing insoluble impurities by filtration to obtain a transparent solution. Adding 112.0mL of water, stirring at room temperature of 30 ℃ for half an hour, and separating out a white precipitate: filtering; ethanol (5 mL each) was washed three times; drying (100 ℃, 1 hour) to obtain white Sb₄O₅Cl₂And (3) powder. The hydrolysis mother liquor is used as electrolyte for recycling.

Example two: referring to the attached figure 1, 50.0mL of the hydrolysis mother liquor of the first example is put into a single-chamber reactor with a metal Sb block as an anode and a Ti sheet as a cathode. The direct current is supplied, the voltage is 14V, the current is 300mA, and the cathode current density is 1500A/m²Electrolyzing at 40 deg.C for 1 hr to discharge H from cathode₂And has black active Sb^*And (5) powder generation. After the electrolysis is finished, taking out the electrode, and continuing heating and stirring until the electrode is black Sb^*Disappearance and filtration to remove insoluble impurities to obtain a transparent solution: stirring for half an hour at the room temperature of 28 ℃ to separate out white precipitate; filtering; ethanol (5 mL each) was washed three times; drying (100 deg.C, 1 hr) to obtain white wineColor Sb₄O₅Cl₂And (3) powder. The hydrolysis mother liquor is used as electrolyte for recycling.

Example three: referring to the attached figure 1, 9.0mL of concentrated hydrochloric acid and 50.0mL of water are put into a single-chamber reactor with a metal Sb block as an anode and a Ti sheet as a cathode. The direct current is supplied, the voltage is 6V, the current is 200mA, and the cathode current density is 1300A/m²Electrolyzing at 50 deg.C for 2.5 hr to discharge H from cathode₂And has black active Sb^*And (5) powder generation. After the electrolysis is finished, taking out the electrode, and continuing heating and stirring until the electrode is black Sb^*And (4) removing insoluble impurities by filtration to obtain a transparent solution. Stirring for half an hour at the room temperature of 27 ℃, and separating out white precipitate; filtering; ethanol (5 mL each) was washed three times: drying (100 ℃, 1hour) to obtain white Sb₄O₅Cl₂And (3) powder. The hydrolysis mother liquor is used as electrolyte for recycling.

Example four: referring to FIG. 1, 1.6g of NaCl was dissolved in 40.0mL of water and placed in a single-chamber reactor with a metal Sb block as anode and graphite as cathode. The direct current is supplied, the voltage is 16V, the current is 400mA, and the cathode current density is 1300A/m²Electrolyzing at 50 deg.C for 1 hr to discharge H from cathode₂And has a black colorSb (antimony)^*Powder is generated; a white precipitate formed in the solution. After the electrolysis is finished, the electrode is taken out, 6.0mL of concentrated hydrochloric acid is added, and the mixture is continuously heated and stirred until the black Sb^*And the white precipitate disappeared, and insoluble impurities were removed by filtration to obtain a transparent solution. Stirring for 1 hour at room temperature of 15 ℃ to separate out white precipitate; filtering; ethanol (5 mL each) was washed three times; drying (100 ℃, 1 hour) to obtain white Sb₄O₅Cl₂And (3) powder. The hydrolysis mother liquor is used as electrolyte for recycling.

Example five: referring to FIG. 1, 1.6g of NaOH was dissolved in 40.0mL of water and placed in a single chamber reactor with a metal Sb block as anode and a stainless steel plate as cathode. The direct current is supplied, the voltage is 8V, the current is 300mA, and the cathode current density is 1300A/m²Electrolyzing at 50 deg.C for 1 hr to discharge H from cathode₂And has black active Sb^*And (5) powder generation. After the electrolysis, the electrode was taken out and concentrated hydrochloric acid 13.0 was addedmL, heating and stirring continuously until the color is black Sb^*And (4) removing insoluble impurities by filtration to obtain a transparent solution. Stirring for 1 hour at room temperature of 16 ℃ to separate out white precipitate; filtering; ethanol (5 mL each) was washed three times; drying (100 ℃, 1 hour) to obtain white Sb₄O₅Cl₂And (3) powder. The hydrolysis mother liquor is used as electrolyte for recycling.

Obtained Sb₄O₅Cl₂The product is analyzed by silver nitrate-ammonium thiocyanate method to have chlorine content of 10.96 percent, and is analyzed by iodine standard solution titration to have antimony content of 76.29 percent, and the atomic number fraction ratio of Sb to Cl, x (Sb)/x (Cl), is 2.0: the X-ray diffraction spectrum line of the product is well matched with the theoretical characteristic spectrum line, and the product component is Sb₄O₅Cl₂(ii) a Scanning Electron Microscopy (SEM) showed that the powder was ellipsoidal with an average particle size of about 0.075 μm.

Example six: referring to the attached figure 2, 15.0mL of concentrated hydrochloric acid and 25.0mL of water are put into a single-chamber reactor with a metal Sb block as an anode and a Ti sheet as a cathode. The direct current is supplied, the voltage is 3V, the current is 300mA, and the cathode current density is 1500A/m²Electrolyzing at 40 deg.C for 3 hr, and discharging H from cathode₂And has black active Sb^*And (5) generating powder. After the electrolysis is finished, taking out the electrode, and continuing heating and stirring until the black Sb is formed^*Disappearance and filtration to remove insoluble impurities to obtain a transparent solution: heating and concentrating the solution to obtain Sb³⁺A solution with a concentration of about 400 g/L.

Adding water 3.0m L into the concentrated solution at room temperature of 28 deg.C, stirring for 1 hr, and depositing white fine powder at the bottom; filtering; ethanol wash (5 mL each) three times; drying (100 ℃, 1 hour) to obtain white powder SbOCl. The hydrolysis mother liquor is used as electrolyte for recycling.

The obtained SbOCl product has a chlorine content of 20.00% by silver nitrate-ammonium thiocyanate method, an antimony content of 70.15% by iodine standard solution titration analysis, and a ratio of atomic number fraction of Sb to Cl, x (Sb)/x (Cl), of about 1.0; the X-ray diffraction spectrum line of the product is well consistent with the theoretical characteristic spectrum line, and the product component is SbOCl. Scanning Electron Microscopy (SEM) showed that the powder was spheroidal with a particle size of about 0.3 μm.

Claims

1. A method for preparing antimony oxychloride, which is characterized by comprising the following steps: dissolving metal antimony by using an electrochemical sacrificial anode method with metal antimony as an anode and an insoluble conductive material as a cathode, and hydrolyzing an electrolyte in an acid solution to obtain antimony oxychloride; the solution of at least one of the electrolysis and hydrolysis systems contains chloride ions.

2. The method of claim 1, wherein: the insoluble conductive material is selected from one of the following materials: iron, steel, carbon steel, stainless steel, nickel, titanium, copper, graphite.

3. The method of claim 1, wherein:

the first step, the metal antimony is used as an anode, insoluble conductive material is used as a cathode for electrolysis, and H is discharged from the cathode in the electrolysis process₂And black active antimony powder Sb^*Generating;

secondly, stopping electrolysis, heating and stirring until the black Sb^*The powder disappears to obtain transparent solution;

thirdly, continuously stirring the solution, and hydrolyzing to generate a white precipitate;

and fourthly, filtering, washing and drying to obtain the antimony oxychloride.

4. The method of claim 3, wherein: in the third step, the acidity C of the solution is controlled_H+Stirring and hydrolyzing at the temperature of 0-40 ℃ and less than 2.5mol/L to generate white precipitate; step four to obtain Sb₄O₅Cl₂。

5. The method of claim 3, wherein: in the third step, the solution Sb was controlled³⁺The concentration is more than or equal to 300g/L, and the acidity C of the solution_H+Stirring and hydrolyzing at the temperature of 0-40 ℃ and more than or equal to 2.5mol/L to generate white precipitate; and step four, obtaining SbOCl.

6. The method of claim 3, wherein: the hydrolysis mother liquor can be recycled.