CN105110382A - Method for preparing high-purity gamma-Fe2O3 iron oxide red pigment - Google Patents

Abstract

The invention relates to a method for preparing high-purity gamma-Fe2O3 iron oxide red pigment. The method includes the following steps: firstly, dissolving the ferrous sulfate solid in water, controlling the obtained solution to be at a certain temperature, adding a certain amount of a flocculating agent, and keeping at a certain temperature; after a certain time, filtering to obtain a refined ferrous sulfate solution; adding saturated ammonium bicarbonate solution into the refined ferrous sulfate solution for synthesizing iron carbonate and iron hydroxide precipitate with high magnetic properties under the conditions of a certain temperature and a pH value. According to the invention, the method is low in cost and simple and convenient to operate; the obtained product is high in stability and suitable for industrial production.

Description

A kind of high-purity gamma-Fe 2o 3the preparation method of ferric oxide red colorant

Technical field

The present invention relates to a kind of high-purity gamma-Fe ₂o ₃the preparation method of ferric oxide red colorant.

Background technology

At the initial stage year sixties, ferrite is for obtained 900 DEG C of calcinings after raw material mixing with the vitriol of analytical pure manganese, zinc, iron.Ferrite cost obtained is in this way high, and environmental pollution is serious.Meanwhile, oxidation ironworks development a kind of " high magnetic permeability ferric oxide ", it does precipitation agent with oxalic acid, because of high cost, is all successively eliminated.

Within 1970, M.J.Ruther delivers " burning ferric oxide for ferritic spraying " first.The feature of this method is with pickle solution during steel rolling for raw material, and obtain in high-temperature spray roasting, product is inexpensive.Be characterized in that product impurity is as SiO ₂content is high, and equipment material requires high, and technical difficulty is large, has formula oxidation ironworks, many Shandongs abroad, but can produce SiO ₂content low, the ferric oxide producer of good physical and chemical properties only has only a few.Domestic as Baosteel, Anshan iron and steel plant, Wuhan Iron and Steel Plant, all successively introduces Shandong formula ferric oxide technology of preparing, but can't produce high-quality iron oxide pigment.

The main method of current martial ethiops industry has sulphate process and Lu Si nanofarad.Sulphate process with enamel iron sheet and sulfuric acid for pigment for raw materials cost is high, quality is good, be applicable to manufacture high-grade magnetic material, this nanofarad of Shandong ferric chloride Solution is carried out roasting oxidation obtain product, can be raw material with steel mill's spent pickle liquor, cost is lower, but product specification is low, is applicable to prepare low-grade magnetic material.By the approach that the method that titanium white by product thing ferrous sulfate is raw material manufacture high-purity magnetic iron oxide is the high purity ferric oxide production method that pollution administration is new with exploration, current Chinese CN110499A discloses the process for purification of titanium dioxide ferrous sulfate.The method is dissolved by ferrous iron, adds sulfuric acid, iron sheet, acidolysis reduction removal of impurities, the processes such as freezing and crystallizing.There are the following problems in suitability for industrialized production for the method: 1. produce a large amount of titanium hydroxide precipitations in hydrolytic process, the pure and impure ratio of sedimentation material is about 2:1, and the stillness of night is easy to filter, but turbid liquid filters very difficult.If discard turbid liquid, then the yield of ferrous sulfate is too low.2. in hydrolytic process, concentration reduces, and pure and impure than increasing, hydrolysis yield is high, but in crystallisation process, concentration is higher, and yield is lower, and crystallization yield is 25%-30%, total recovery only about 20%.The method that prior art adopts be in and oxidation style, the synthetic method bicarbonate of ammonia that Chinese patent CN1049142A adopts regulates pH value, and blowing air oxidation generate Fe(OH) ₃precipitation, water content is large, and this method has following shortcoming: 1 Fe(OH formed) ₃precipitation water content is large, and in cotton-shaped, be difficult to filtration washing, wash water is many, industrial operation difficulty.2. in product, magnesium addition content easily exceeds standard, 3.Fe(OH) ₃precipitation is long for time of drying, needs 3-5 hour, and in block after calcining, need to pulverize, production sequence is many, and energy consumption is high.

Summary of the invention

In order to solve above-mentioned technical problem, the object of this invention is to provide a kind of high-purity gamma-Fe ₂o ₃the preparation method of ferric oxide red colorant.After the method removal of impurities, yield can reach more than 90%, and require that synthesizing the precipitation produced is easy to filtration washing, without the need to pulverizing, and be suitable for suitability for industrialized production, product fine, magnetic function is strong simultaneously.

In order to realize above-mentioned object, present invention employs following technical scheme:

A kind of high-purity gamma-Fe ₂o ₃the preparation method of ferric oxide red colorant, the method comprises the following steps:

1) purify, tentatively obtained copperas solution is passed into steam and is warming up to 55 ~ 65 DEG C, in the copperas solution after intensification, add the flocculation agent of 0.25 ~ 0.4% of copperas solution total mass; Stir 5-10 minute, treat that flocculation agent is evenly distributed, place 10 ~ 15 hours;

2) filter, with 300 ~ 350 object sieves by its clear liquor and precipitate and separate, get clear liquor and be POV ferrous iron solution;

3) synthesis oxidation, the POV ferrous iron solution prepared is placed in reaction container, and in reaction container, adds the saturated ammonium bicarbonate soln prepared, the content detecting mixed serum residual sulfuric acid ferrous iron after feeding intake controls at 3.5 ~ 4.5g/100ml; And in reaction container, pass into air slurries are oxidized, pass into air, and heat up to slurries, temperature controls at 55 ~ 65 DEG C; Iron oxide red intermediate slurries are taken out after 4 ~ 6 hours in reaction;

4) iron oxide red intermediate slurries are placed in deposit bucket, carry out rinsing with tap water to it by rinsing, and rinsing is complete carries out suction filtration to iron oxide red intermediate slurries, after obtaining dense thick slurries afterwards;

5) press filtration, obtains filter cake, then dries in 100 ~ 110 DEG C of baking ovens iron oxide red intermediate filter cake;

6) calcine, 240 ~ 280 DEG C of temperature lower calcinations 1.5 ~ 3 hours; After having calcined, superfine grinding is carried out to the block material obtained, can finished product be obtained.

As preferably, by titanium white by product thing ferrous sulfate solid, be dissolved in the water, and put into enough iron sheets, prepare copperas solution.

Principle of the present invention is: by water-soluble for titanium white by product thing ferrous sulfate solid, this solution is muddy and has a lot of macroscopic impurity and heavy metal element and ferrous sulfate solid long-term exposure to define a large amount of ferric sulfate in atmosphere, so put into enough iron sheets in rough copperas solution, make Zero-valent Iron that the ferric ion contained in solution is reduced into ferrous ion, because flocculation agent has very strong adsorption for the beavy metal impurity produced in reaction process and other impurity, and at the temperature of 80 DEG C, there is the strongest throwing out, therefore a certain amount of flocculation agent can be added in the copperas solution of rough 80 DEG C and carry out removal of impurities.

In oxidative synthesis process, there are ferrous sulfate and ammonium bicarbonate soln at 60 DEG C, react when passing into air.Concrete equation is as follows:

FeSO ₄+2NH ₄HCO ₃ FeCO ₃↓+（NH ₄) ₂SO ₄+H ₂O+CO ₂↑

3CO ₃ ^2-+2Fe ²⁺+3H ₂O 2Fe(OH) ₂↓+3CO ₂↑

4Fe(OH) ₂＋O ₂ 4γ-FeOOH＋2H ₂O

γ-FeOOH γ-Fe ₂O ₃

The present invention is owing to have employed above-mentioned technical scheme, and after the method removal of impurities, yield can reach more than 90%, and require that synthesizing the precipitation produced is easy to filtration washing, without the need to pulverizing, and be suitable for suitability for industrialized production, product fine, magnetic function is strong simultaneously.

Accompanying drawing explanation

Fig. 1 is schema of the present invention.

Embodiment

Get 40kg titanium white by product thing FeSO ₄dissolution of solid is in 60kg water, make copperas solution, enough iron sheets are placed in copperas solution, in copperas solution, pass into steam, temperature is controlled at 80 DEG C, and PH is controlled about 5, take out liquid and put into deposit bucket, and in deposit bucket, add the flocculation agent of liquid mass 1/100 quality, place 48 hours, take out clear liquor.

104 liters, the ferrous sulfate that concentration is 37.5% is added in reaction container, pass into air to ferrous sulfate to heat, temperature is controlled between 60 DEG C, and open stirring, open air, air flow control is made slowly to add reaction container at the ammonium bicarbonate soln that the concentration prepared is 14.3% by 2.1m3/h., after adding ammonium bicarbonate soln, about half an hour carries out PH mensuration and residual sulfuric acid ferrous content mensuration to reactant in bucket, PH controls about 6.2, ferrous sulfate content controls at about 4% Shi Weijia, if ferrous sulfate content is higher than 5%, then continue to add appropriate ammonium bicarbonate soln, ferrous sulfate content is controlled at 3.5-4.5%.Reaction is continued 2 hours and starts feeding, rinsing is carried out to feed liquid, carry out suction filtration to ferrous sulfate content without after residue, the material of suction filtration is positioned in the baking oven of 105 DEG C and dries.Calcine in the retort furnace block material of oven dry being put in 250 DEG C, calcination time controls at 2 hours, finally carries out superfine grinding to the magnetic oxygenated iron block material after calcining, namely obtains the red finished product of high-purity magnetic iron oxide.

Claims (2)

1. a high-purity gamma-Fe ₂o ₃the preparation method of ferric oxide red colorant, is characterized in that the method comprises the following steps:

1) purify, tentatively obtained copperas solution is passed into steam and is warming up to 55 ~ 65 DEG C, in the copperas solution after intensification, add the flocculation agent of 0.25 ~ 0.4% of copperas solution total mass; Stir 5-10 minute, treat that flocculation agent is evenly distributed, place 10 ~ 15 hours;

2) filter, with 300 ~ 350 object sieves by its clear liquor and precipitate and separate, get clear liquor and be POV ferrous iron solution;

3) synthesis oxidation, the POV ferrous iron solution prepared is placed in reaction container, and in reaction container, adds the saturated ammonium bicarbonate soln prepared, the content detecting mixed serum residual sulfuric acid ferrous iron after feeding intake controls at 3.5 ~ 4.5g/100ml; And in reaction container, pass into air slurries are oxidized, pass into air, and heat up to slurries, temperature controls at 55 ~ 65 DEG C; Iron oxide red intermediate slurries are taken out after 4 ~ 6 hours in reaction;

4) iron oxide red intermediate slurries are placed in deposit bucket, carry out rinsing with tap water to it by rinsing, and rinsing is complete carries out suction filtration to iron oxide red intermediate slurries, after obtaining dense thick slurries afterwards;

5) press filtration, obtains filter cake, then dries in 100 ~ 110 DEG C of baking ovens iron oxide red intermediate filter cake;

6) calcine, 240 ~ 280 DEG C of temperature lower calcinations 1.5 ~ 3 hours; After having calcined, superfine grinding is carried out to the block material obtained, can finished product be obtained.

2. a kind of high-purity gamma-Fe according to claim 1 ₂o ₃the preparation method of ferric oxide red colorant, is characterized in that, by titanium white by product thing ferrous sulfate solid, being dissolved in the water, and putting into enough iron sheets, prepare copperas solution.