JPS60387B2 - Manufacturing method of hydrated iron oxide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for obtaining hydrated iron oxide from Fe ions extracted into an organic phase.

There have been a huge number of patent applications related to methods for producing iron oxide for magnetic materials, but all of them are based on the conditions for precipitating Fe ions in an aqueous solution. The process is done by adjusting the temperature, time and oxidation rate.

However, since there are many impurities in the Fe-containing aqueous solution, there is a drawback that hydrated iron oxide having the desired properties cannot be obtained. In addition, in the conventional technology, hydrated iron oxide is used by adding alkali to Fe ions contained in strong acid, so the acid cannot be recovered, and the amount of alkali used is large, making the produced iron oxide expensive. There was a drawback. The present invention was made to overcome the drawbacks of conventional methods, and includes alkyl phosphoric acids, alkylaryl phosphoric acids, dialkyldithiophosphoric acids, diaryldithiophosphoric acids,
One or more extractants selected from the group of hydroxyoximes and carboxylic acids are diluted with petroleum hydrocarbon to extract and contain Fe ions, and the organic solvent contains a reducing agent. or no NH4HF2
, Fe ions are stripped into an aqueous phase by contacting with a stripping aqueous solution containing an N ratio of F, and then the Fe ions in the aqueous phase are converted into hydrated iron oxide by adjusting the H + ion concentration of the stripping aqueous solution. This article relates to a method for producing hydrated iron oxide, which is characterized by its characteristics.

Note that the present invention is based on Tokudo Sho 50, which has already been disclosed.
It is also possible to combine the techniques of Japanese Patent Application No. 089433, Japanese Patent Application No. 54-3699, and Japanese Patent Application No. 55-11930.

The details of the present invention will be explained below based on the drawings, but the present invention is not limited thereto.

First, the flow sheet shown in FIG. 1 will be explained.

One or more extractants selected from the group consisting of alkyl phosphoric acids, alkylaryl phosphoric acids, dialkyldithiophosphoric acids, diaryldithiophosphoric acids, hydroxyoximes, and carboxylic acids are diluted with a petroleum hydrocarbon. Organic solvent A containing Fe ions and NH4HF2
Or remove the peeling (aqueous) solution C containing the N ratio F in the peeling step B.
By contacting at
-... mR2Fe12N ratio Fko2R・N ratio + FeF2
10......■In addition to formulas (1} and {2), side reactions such as formula '3} may also occur. R3F
e+ is 4HF 2 days + (N ratio) 3FeFF...
...'3} Next, the stripping solution C containing Fe is led to a neutralization step D, and by adjusting the H+ ion concentration with NH3 or NH40 days, hydrated iron oxide E can be produced as shown in the formula {4}.

FeF210F-+ is ratio OH2Fe00H ↓ Jushu ratio F 10 days 20... (4} Furthermore, if there is an excess of Nurion OH, Fe00 days will be changed all at once as shown in the formula '5} generate.

R3Fe+Suhi+3NH40 NigitsuneNH40Fe00H
+S/N ratio F+Day 20...'51 At the same time, NH4F is regenerated in the neutralization process D and returned to the stripping process B as stripping liquid C.

Note that reducing agent F (N2 day 4, day 2 S, S02, etc.) may be added to the stripping aqueous solution containing N day day F2 and NH4F, or reducing agent F may be added at the initial stage when adjusting the H+ ion concentration of the stripping solution. It is also possible to change the state of hydrated iron oxide by adding . Furthermore, Fe after adjusting the H+ ion concentration
By allowing the suspension of the 00-day precipitation to stand for a long time, needle-like crystals of hydrated iron oxide E can be obtained.

The flow sheet of FIG. 2 is the same as that of FIG. 1 except that the extraction step date and the heating step Q are added.

That is, in the pre-process of stripping process B, Fe ions are extracted from any aqueous solution J containing Fe ions using the same extractant (organic solvent A) as in the flow sheet of FIG.
}, '7-In addition to setting the extraction process date as shown in the formula, Fe3103R, day2 R3Fe19th day...
■Fe2 112R・HkoR2Fe12th 10……{7}
A heating step C is provided in which hydrated iron oxide E obtained in neutralization step ○ in FIG. 1 is heated in air K to produce acicular iron oxide M. The gas G obtained in the heating step Q is used again as a stripping liquid C. Fig. 3 shows the flow sheet of Fig. 1 with the same extraction step and heating step Q as shown in Fig. This is a flow sheet that includes a process for producing metallic iron powder N.

In addition, in the neutralization process D, air K is blown in and the temperature condition is set to 4.
By adjusting the temperature to 0°C to 100°C, the conversion ratio of ferrous to ferric iron can be adjusted and acicular hydrated iron oxide can be produced. The extractants used in the present invention are shown below.

The group of alkyl phosphoric acids is selected from among the compounds shown in 1 to 'q below: where R is an alkyl group generally containing from 4 to 1 needle carbon atoms.

D2EHPA (di-2-ethylhexyl phosphoric acid) shown in Reference Examples and Examples belongs to the above-mentioned group, and the alkyl group is C
8th, 7th.

The alkylaryl phosphoric acids used in the invention are selected from the following group: (wherein R generally represents an alkyl group containing from 4 to 18 carbon atoms and A generally represents an aryl group).

OPPA (octylphenyl phosphoric acid) shown in the reference example has the above formula where R=C8,7 and A=C7.

The group of alkyl dithiophosphoric acids or aryldithiophosphoric acids used in the present invention is selected from among the following compounds: (wherein are generally alkyl or aryl groups containing from 4 to 18 carbon atoms).

○2EHPDTA (di-2-ethylhexyl-dithiophosphoric acid) shown in the reference example has R=C8,7 in the above formula.

The hydroxyoximes used in the present invention are selected from the following group of compounds: (wherein R=day, C&, or B, and X=C, day).

Hydroxyoximes similar to this can of course be used.

SME-529 shown as a reference example is a trade name of Shell Kagaku (■) and is the above-mentioned compound where R=CQ.

The carboxylic acid-based extractants used in the present invention are then selected from the following group of compounds: (wherein R is generally an alkyl group having from 4 to 1 carbon atoms).

V-10 (Versatile) shown in Reference Examples and Examples
10) is a trade name of Shell Kagaku (1) and belongs to the above-mentioned group, and the alkyl group has 9 to 11 carbon atoms.

The petroleum hydrocarbon diluent used in the present invention may be aromatic, aliphatic, or a mixture thereof. Miscellaneous carbon-hydrogen mixtures such as kerosene are also commonly used.
The extractant in the organic solvent is selected from the groups of alkyl phosphoric acid, alkylaryl phosphoric acid, dialkyldithiophosphoric acid, diaryldithiophosphoric acid, hydroxyoxime, and carboxylic acid depending on the properties of the aqueous solution containing the target Fe ions and the content thereof. Depending on the types of impurities to be extracted and their coexistence ratios, one or more types are selected, and the type of extractant and the method of mixing the extractants are determined.

The extractant concentration is similarly determined depending on the target aqueous solution and impurities, but is generally adjusted to 2 to 90% (by volume) before use. When the present invention is implemented industrially, there are the following advantages.

'11 High-purity hydrated iron oxide can be obtained at low cost, and by heating and reducing it, it can be sold as a high-purity magnetic material.

'21 Iron removal in the wet smelting process of non-ferrous metals can be performed economically. ``As a result, the loss of coexisting valuable metals is suppressed, so the extraction rate of non-ferrous metals is improved.

{3} It can be used to treat industrial waste that contains a large amount of iron and valuable metals, and since the iron it contains can also be sold as a magnetic material, economical recycling becomes possible.

'4} If used to recover waste acids (FiN03, HF, HC〆, specific S04 monoacid and concentrated acid) used for surface treatment of metal materials and metal products, process management of the pickling tank becomes easy. Moreover, since the contained Fe ions can be sold as electronic materials, it can be used as a pharmaceutical recovery device.

The present invention will be specifically explained below with reference to Examples and Reference Examples.

Reference Example 1 NH4F and N in the stripping solution were sampled using an organic solvent consisting of 30% D2EHPA and 70% n-paraffin extracted at a ratio of 13.6 ions of Fe30 ions.
Varying the specific HF2 concentration from 50 to 15 females/event, NH3
Table 1 shows the results of determining the peeling rate by adjusting the pH.

Furthermore, the relationship between the NH4F concentration in the stripping solution and the stripping rate is shown in FIG. Table 1. However, peeling conditions: ○/A=1, cooling time: 1 minute, temperature: 28.

Experiments were conducted with 5qo.

Reference Example 2 An experiment was conducted in which Fe ions were extracted using an organic solvent prepared by diluting various extractants with isoparaffin.

Table 2 shows the peeling results when 30 Fe ions were extracted, and Table 3 shows the peeling results when 20 Fe ions were extracted. For each organic solvent, the diluent is imparaffin, and the stripping solution is NH4FIOOg.
The experiment was conducted using No. 1, initial pH = 9, O/A = 1, cooling time: 1 sample, and temperature: 28.500.

The following extractants were used in Table 2 and Table 3. ethylhexyl dithiophosphoric acid), SME-529 (Shell Chemical brand name,
hydroxyoxime).

Example 1 Fe ions in an organic phase consisting of 30% D2EHPA and 70% isoparaffin are exfoliated into an aqueous phase, and the aqueous phase contains Fe ions and crystals of ferric ammonium fluoride such as (NH4)3FeF6 or (NH4)2FeF. Add NH3 or N to the suspension
As a result of neutralization by adding specific OH, dissolved Fe ions in the water phase change to hydrated iron oxide as shown in the formula {4}, and crystals of iron ammonium fluoride also change to hydrated oxidation as shown in the following formula turned into iron.

(N) 3FeF6 10 ga days 40 days ko Fe00H↓10 haiku N
Ratio F 10 days 20...'8' Figure 5 shows the relationship between the total concentration of dissolved Fe ions and iron ammonium fluoride in relation to the p-law of the aqueous phase in this case.

In the figure, "L" and "lt" are the cases where 15 female and 8 female NH4F were used, respectively. Example 2 Fe ions 18. Extract the crane/so, then N ratio F20
After contacting with a stripping solution containing 0g of water for 2 days and removing almost 100% of the Fe ions in the organic phase, 60g of
After leaving it for a minute, the pH was raised to 10 with NH3 gas and then flooded to 600 to 800. The resulting hydrated iron oxide was observed under an electron microscope, and as a result, needle-shaped crystals were obtained.

Example 3 Fe20 ions were added to an organic solvent prepared by diluting 3002EHP+20% V-10 with kerosene for 8.5 hours. After extraction, the pH of the N ratio F20 female/sleeve exfoliated aqueous solution was raised to pH = 10 using NH3, and the temperature was 80 qo to 10 qo.
Hold at 0°C for 2 hours, then continue blowing air for 6 hours.
As a result of observing the hydrated iron oxide obtained during time aging with an electron microscope, it was confirmed that no needle-shaped crystals were obtained.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the flow sheet of the present invention, and FIG. 2 is a diagram showing the flow sheet of the present invention.
A reference flow sheet diagram for carrying out the method of the present invention, which includes an extraction step for extracting Fe ions from an ion-containing aqueous solution and a heating step for hydrated iron oxide, and FIG. Figure 4 is a reference flow sheet diagram for carrying out the method of the present invention, including a heating step for thermally reducing hydrated iron oxide in an air stream containing 2, and Figure 4 shows the relationship between the concentration of N in the stripping solution and the stripping rate. Figure 5 shows the pH of the stripping aqueous solution.
FIG. 3 is a diagram showing the relationship between the total concentrations of dissolved Fe ions and iron ammonium fluoride. A...Organic solvent, (containing Fe ions), B...
...Peeling process, C...Removal liquid, D...
Neutralization step, E... Hydrous iron oxide, F...
Reducing agent, G...Gas, Day...Extraction process, J...Fe ion-containing aqueous solution, K...Air, L...Day 2-containing air flow , M...acicular iron oxide,
N: Needle-shaped metallic iron powder, Q: Heating process. Groove - Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1 selected from the group consisting of alkyl phosphoric acid, alkylaryl phosphoric acid, dialkyldithiophosphoric acid, diaryldithiophosphoric acid, hydroxyoxime and carboxylic acid.
The organic solvent is obtained by diluting a species or two or more extractants with a petroleum hydrocarbon to extract and contain Fe ions,
NE_4HF_2NH^ with or without reducing agent
Fe is removed by contacting with a stripping aqueous solution containing 4F.
A method for producing hydrated iron oxide, which comprises exfoliating ions into an aqueous phase, and then converting Fe ions in the aqueous phase into hydrated iron oxide by adjusting the concentration of H^+ ions in the aqueous exfoliation solution.