CN1085625C

CN1085625C - Preparation of high-purity superfine electron-level ferric oxide powder

Info

Publication number: CN1085625C
Application number: CN00111081A
Authority: CN
Inventors: 陈代荣; 焦秀玲; 于铭勤; 张立宏
Original assignee: Shandong University
Current assignee: Shandong University
Priority date: 2000-04-25
Filing date: 2000-04-25
Publication date: 2002-05-29
Anticipated expiration: 2020-04-25
Also published as: CN1267640A

Abstract

The present invention belongs to the field of inorganic non-metallic materials. The present invention has the primary coverage that iron ore, industrial hydrochloric acid and liquid ammonia are utilized as key raw materials for preparing course ferric chloride solution, and ferric chloride solution with high purity is obtained by extraction and purification; then, by precipitation by leading the liquid ammonia and a hydrothermal reaction, the ultra-fine electronic-grade powder of alpha-Fe2O3 with high purity and the granularity of 0.03 to 0.20 micrometers is prepared. The present invention solves the existing problems of the prior art, such as complicated technique, high production cost, environment pollution, etc., and the present invention has the advantages of simple technique, low production cost, easy industrial production in a large scale, no environment pollution, etc.

Description

High-purity superfine electronic grade ferric oxide powder and preparation method thereof

The invention relates to a method for preparing high-purity superfine electronic grade ferric oxide (α -Fe)₂O₃) A preparation method of powder belongs to the field of inorganic nonmetallic materials.

α-Fe₂O₃The powder is used for magnetic material, electronic and telecommunication element material and for coloring fluorescent powder of color kinescope, and can raise red light brilliance and prolong service life. The more uniform the particle structure of the powder, the more regular the particles, the smaller the particle size and the better the material performance.

Preparation of α -Fe₂O₃The powder method is generally the following process route, and the used raw materials are scrap iron, titanium dioxide byproduct ferrous sulfate, steel mill pickling waste liquid crystallized iron salt and other waste byproducts:

the prior preparation process has the defects of complex process, high production cost, uneven powder granularity, large environmental pollution and the like.

The invention aims to solve the problems of low product purity, high cost, great environmental pollution and poor powder granularity in the prior art, and provides a new process route which comprises the following steps:

the method mainly comprises the steps of preparing a rough ferric chloride solution by using iron ore, industrial hydrochloric acid and liquid ammonia as main raw materials, extracting and purifying to obtain a high-purity ferric chloride solution, and then performing liquid ammonia precipitation and hydrothermal reaction to obtain the high-purity superfine electronic grade α -Fe with the granularity of 0.03-0.20 micrometer₂O₃The powder is prepared by the following specific steps:

1) firstly, according to the weight ratio of iron ore to hydrochloric acid of 1: 3-10, adding 29-31% industrial hydrochloric acid to be diluted with water to 16-22% and putting the iron ore into a reactor, stirring for 0.2-2 hours, introducing chlorine gas, wherein the weight ratio of the industrial hydrochloric acid to the iron ore is determined according to the ore type, the ratio of hematite to magnetite is 1: 100-150, the ratio of magnetite to magnetite is 1: 7-10, adding 0.01-1% concentration and 170-800 ten thousand molecular weight polyacrylamide solution into the reacted solution, the weight ratio of polyacrylamide to iron ore is 1: 1000-3000, settling for 0.1-1 hour, naturally cooling to room temperature, filtering to obtain a rough ferric chloride solution, and then, obtaining a rough ferric chloride solution

2) Adding hydrochloric acid into the rough ferric chloride solution to enable the concentration of free acid to reach 2-5 mol/L, extracting with methyl isobutyl ketone or tributyl phosphate/benzene or tributyl phosphate/sulfonated kerosene, wherein the volume ratio of an organic phase to an aqueous phase is 1: 0.5-3, back-extracting the organic phase with pure water or dilute ammonia water with the concentration of 0.05-0.5 mol/L, the volume ratio of the aqueous phase to the organic phase is 1: 0.7-2.0, adding polyacrylamide solution into the aqueous phase, settling for 0.1-1 hour, filtering to obtain a refined ferric chloride solution, and then adding the polyacrylamide solution into the aqueous phase to settle for 0.1-1 hour to obtain a refined ferric chloride solution

3) Adding a refined ferricchloride solution into a reactor, adding liquid ammonia until the pH value of the solution reaches 4-9, heating to 160-200 ℃ at a heating rate of 2-10 ℃/min, keeping the temperature for 2-8 hours, cooling to room temperature at a cooling rate of 2-10 ℃/min, centrifuging to separate out a precipitate, washing with purified water for three times, and then washing with purified water

4) And (3) putting the precipitate into a muffle furnace, heating to 400 ℃ at a heating rate of 3-10 ℃/min, keeping the temperature for 1-4 hours, and naturally cooling to room temperature to obtain the high-purity superfine electronic-grade ferric oxide powder.

The superfine α -Fe prepared by the method of the invention₂O₃The crystal form of the powder is a corundum structure, the appearance of the particles is uniform spherical, ellipsoidal or rhombic, the size is 0.03-0.20 micrometer, and the powder has good material performance.

The preparation method provided by the invention belongs to the preparation of α -Fe by an acid method₂O₃Powder, but different from any existing method, has the advantages that the refined ferric chloride solution which can be used for hydrolysis is obtained by extracting and back-extracting the crude ferric chloride solution obtained by the acidolysis of iron ore by industrial hydrochloric acid, wherein the residual small amount of extractant simultaneously controls α -Fe₂O₃The iron oxide powder obtained by the method of the invention is α -Fe with corundum structure₂O₃The particle size is 0.03-0.20 micron, the difference between the maximum particle radius and the minimum particle radius is only 0.01 micron, the uniformity is good, and the method has high material performance and chemical activity.

The invention has another characteristic that other reagents can be recycled or partially recycled except the iron raw material and the hydrochloric acid in the whole preparation process, and the environment pollution can not be generated, which is used for preparing α -Fe by an acid method₂O₃The other characteristic of the invention is α -Fe₂O₃The powder has high purity, and has very low content of impurity ions except water, such as silicon content of 46 × 10^-6，Fe₂O₃The content is not less than 99.9%.

Example 1

Adding 7 parts of 22% industrial hydrochloric acid into 1 part of magnetite powder, stirring for 0.5 hour for dissolving, naturally cooling to room temperature, adding 0.005 part of 0.25% polyacrylamide solution, settling for 0.2 hour, filtering, adding 2 parts of 22% industrial hydrochloric acid into filtrate, extracting the solution with 9 parts of tributyl phosphate/benzene mixed solution (volume ratio 1: 1) to obtain an organic phase I and a raffinate II, performing three-time back extraction on the organic phase I with 9 parts of deionized water to obtain an aqueous phase I and an organic phase II, continuously extracting the raffinate with the organic phase II to obtain an organic phase III, performing three-time back extraction on the organic phase III with 9 parts of deionized water, mixing the obtained aqueous phase and the aqueous phase I, adding 0.005 part of 0.25% polyacrylamide solution, settling for 0.5 hour, filtering to obtain a refined ferric chloride solution, introducing liquid ammonia into the solution until the pH value is 5, placing the solution into a reaction vessel, reacting at 160 ℃ for 4 hours, naturally cooling to room temperature, centrifugally separating, washing the solid product with deionized water three times, roasting at 400 ℃ for 1 hour to obtain Fe in the product₂O₃99.92% of silicon and 32X10 of silicon^-6The particles are diamond-shaped and have a size of 0.04-0.05 μm.

Example 2

Taking 1 part of magnetite powder, adding 6 parts of industrial hydrochloric acid with the concentration of 22%, stirring for 0.5 hour for dissolution, introducing 0.12 part of chlorine, naturally cooling to room temperature, adding 0.004 part of 0.25% polyacrylamide solution, settling for 0.2 hour, filtering, adding 2 parts of 22% industrial hydrochloric acid into filtrate, extracting the solution with 8 parts of tributyl phosphate/benzene mixed solution (volume ratio is 1: 1) to obtain an organic phase I and a raffinate II, and then extractingThen, carrying out three-time back extraction on the organic phase I by using 8 parts of deionized water to obtain a water phase I and an organic phase II, then, continuously extracting raffinate by using the organic phase II to obtain an organic phase III, carrying out three-time back extraction on the organic phase III by using 8 parts of deionized water, mixing the obtained water phase with the water phase I, adding 0.004 part of 0.25 percent polyacrylamide solution, settling for 0.5 hour, filtering to obtain a refined ferric chloride solution, introducing liquid ammonia into the solution until the pH value is 5.5, placing the solution into a reaction vessel, reacting for 4 hours at 200 ℃, naturally cooling to room temperature, carrying out centrifugal separation, washing a solid product with the deionized water for three times, roasting for 1 hour at 600 ℃, and carrying out Fe roasting on the product₂O₃99.90 percent of silicon content and 46 multiplied by 10 percent of silicon content^-6The particles are spherical and have a size of 0.09 to 0.10 micrometer.

Claims

1. A preparation method of high-purity superfine electronic grade ferric oxide is characterized in that after iron ore and industrial hydrochloric acid are used as main raw materials to prepare a crude ferric chloride solution, a refined ferric chloride solution is obtained through extraction and purification, and then liquid ammonia precipitation is carried out to prepare high-purity superfine electronic grade ferric oxide powder with the granularity of 30-200 nm, and the preparation method comprises the following steps:

3) Adding a refined ferric chloride solution into a reactor, adding liquid ammonia until the pH value of the solution reaches 4-9, heating to 160-200 ℃ at a heating rate of 2-10 ℃/min, keeping the temperature for 2-8 hours, cooling to room temperature at a cooling rate of 2-10 ℃/min, centrifuging to separate out a precipitate, washing with purified water for three times, and then washing with purified water

2. The method for preparing high purity electronic grade ferric oxide powder as claimed in claim 1, wherein the acid solution obtained by extracting the crude ferric chloride solution with organic solvent is partially reused for acidolysis of iron ore, and is partially neutralized with dilute ammonia water to produce agricultural ammonium chloride, and the organic extractant is washed with water and then recycled.

3. The ultrafine ferric oxide powder prepared by the method according to claim 1, wherein the crystal form of the powder is corundum, the particle shape is uniform spherical, ellipsoid or rhombohedral, the particle size is 0.03-0.20 micron, and the difference between the maximum particle radius and the minimum particle radius is 0.01 micron.