CS225438B1 - Production of alpha-pheo/oh/ of the copperas by wasteless technology - Google Patents

Description

The present invention relates to a process for the production of ε-PeO (OH) by non-waste technology from green, vitriol (oC-FeOCOH) is an important technical raw material and is mainly used in the production of paints, magnetopigments for audio, video, computer memory etc. The production is largely concentrated on processes of oxidizing iron salts with air or oxygen in an alkaline environment by mixing the P 6 salts with the alkali to precipitate hydroxide, which is oxidized by introducing gaseous oxidants. Due to the requirements of the processing industries for the quality of .alpha.-PeO (OH) (grain size, crystalline structure, impurity content, etc.), the reaction mechanism of the oxidation of the precipitated iron hydroxide is of decisive importance. Methods for influencing both the precipitation of hydroxides and their oxidation are therefore the subject of a number of patents.

However, the prior art processes have some serious disadvantages, such as technical problems. mixing the gelling iron hydroxide suspensions, ensuring perfect dispersion of the gaseous oxidizing agents in the hardly miscible suspensions and the associated formation of iron oxides of the desired grain size.

The aforementioned drawbacks have no process for the preparation of -PeO (OH) by the non-waste green vitriol technology of the invention, which consists in reacting aromatic mono- or dinitro compounds with solubilizing groups in the molecule and optionally with other alkyl, halogen substituents , hydroxyls, alkoxyls and NHg groups on aromatic nuclei, vitriol, and alkali metal, caustic earth or ammonium hydroxides or carbonates in an aqueous medium, preferably with the addition of surfactants, at temperatures between 30 ° C and the boiling point of the reaction mixture wherein the pH of the system is maintained above 6.5 and then solid

-2223 438 eC-PeO (OH) is mechanically separated from the solution from which the resulting amino compounds are precipitated with sulfuric, hydrochloric, nitric or phosphoric acid, and after mechanical separation, a solution of inorganic salts with a predominant sulfate content is obtained.

For the preparation of the present invention, a 'green' vitreous may be used, which falls from the production of titanium dioxide or from pickling of metallurgical materials.

Ammonia or an aqueous solution thereof may be used as the pH regulator of the reaction mixture,

In the case of the oxidation of green vitriol by dinitro compounds, only the equivalent of green vitriol corresponding to one nitro group is reacted and the corresponding nitroamino compound is isolated from the reaction mixture. .

The production of? -PeO (OH) can be carried out in a flow stirred reactor where the reaction is carried out. the components mix continuously.

Among the mono- or dinitroso compounds, for example, benzene, toluene, xylenes, diphenyl, diphenylmethane, dibenzyl, stilbene, naphthalene, acenaphthene, carbazole, anthraquinone and a variety of similar nitro compounds useful as tar dyes, pharmaceuticals, agrochemicals and rubber products are suitable. .

The solubilizing groups used in the nitro compounds may be, for example, a sulfo group, a carboxyl group, but also a sulfamido group which causes alkali solubility or a similarly functioning phenolic hydroxyl.

Thus, free acids or their salts can be used, such as nitrobenzenesulfonic acids, nitrotoluenesulfonic acids, nitrated o-, m- and p-xylenesulfonic acids, chloronitrobenzene toluenesulfoic acids, nitrophenolsulfamides, o-, m- and p-nitrobenzoic acids, nitrobuzenedicarboxylic acids such as acid nitrophthalic, 5-nitroisophthalic, nitroterephthalic, 1-nitronaphthalene-5- or -6- or -7- or -8-sulfonic acid, 2-nitronaphthalene-6-sulfonic acid, 4-nitrodiphenyl-4'-sulfonic acid, 4- difenylraetan nitro-4-sulfonic acid ^from p-nitranilinsulfokyselinu l-amino-4-5225 438 nitroantrachi-non-2-sulfonic acid, nitroacenaftensulfonové acid 4-nitro-4--aminostilben * 2,2 ^< 'disulfonic acid, 1-nitronaphthalene-4,8-disulfonic acid, 2-nitronaphthalene-4,8-disulfoic acid, further dinitro compounds such as dinitrobenzenesulfoacids, dinitronaphthalenesulfoacids, 4,4 ^z -dinitrodiphenylethane-2,2'-disulfoic acid, 4, 4 * -dinitrostilben-2,2'-dis ulfoacid, 1-nitronaphthalene-3,6,8-trisulfoacid and virtually all other nitroaromatic sulfoacids and their salts, which have so far been reduced by iron, Bechamp, or sulfites, hydrosulfite or sulfides or other metals, e.g. Zn.

Green vitriol - essentially ferrous sulfate heptahydrate is an affordable and inexpensive raw material; in technical practice, considerable quantities are produced in the production of titanium dioxide or in the pickling of sheet metals in metallurgy. If the content of impurities does not exceed the permissible limit, waste green vitriol may be used.

Among the agents capable of maintaining the desired pH of the reaction medium are hydroxides such as e.g. NaOH, KOH, NH? OH, OaCOHJg, Ba (OH) g, or carbonates such as Na ₂ 00 ^ K ^ CO ^, (ΝΉ ^) ₂ 00 ^ or. Na 2 CO 3, KHCO 3, and the like. NH 4 OH 1 can be used in place of NH 4 OH 1, the introduction of which into the aqueous medium produces hydroxide.

The process according to the invention can be practiced by adding, for example, the selected hydroxide or carbonate to the aqueous solution or suspension of the nitro compound, then heating the mixture to the desired temperature and adding green vitriol. Another alternative may be to mix the nitro compound with green vitriol and, after heating to the specified temperature, the selected hydroxide or carbonate is added. A further variation is the process for the production of? -PeO (OH) by adding concomitant green vitriol and the selected hydroxide or carbonate either in solid form or as solutions to the solution or suspension of the nitro compound in water.

According to the invention, ultrafine-grained cO-FeO (OH) can be prepared by adding additives to the reaction mixtures such as ZnSO4, tartaric acid, citric acid, alkyl sulfates, alkylarylsulfonates, polyglycols, oleic acid, stearic acid and a variety of other known surfactants. active substances which can inhibit the growth of crystals and prevent their agglomeration.

With the use of waste green vitriol, for example from the production of titanium white 225 438, the concomitant impurities can assume the function of crystal growth regulators as well as their agglomeration.

Formation of? -PeO (OH) occurs over a wide temperature range; a temperature interval of 50 to 90 ° C is suitable for the production, in which the reaction rates and the associated heat development are sufficient for the autothermal production process ·

According to the present invention, ε-PeO (OH) can also be produced by selecting a molar ratio for the reaction between the green vitriol and the dinitro compounds so as to reduce only one nitro group so that a partial reduction occurs to give the amino nitro compound. This means that in the reacting system, an oxidizing environment is ensured until the end of the reaction, and therefore unreacted Fe @ - compounds cannot occur as can be the case when the total reduction of nitro compounds is inaccurate.

The principle of separation of individual products from the mixture after the reaction between the green vitriol and the nitro compound can be illustrated by the example of reduction of m-nitrobenzenesulfoacid in aqueous ammonia; the obtained suspension of α-PeO (OH) in an aqueous solution of ammonium m-aminobenzenesulfonate and ammonium sulfate is subjected to mechanical separation, solid oC-PeO (OH) is separated, the filtrate is acidified with sulfuric acid, the separated m-aminobenzenesulfonic acid inner salt is mechanically separated. it separates from the mother liquors, which represent a relatively very ammonium sulfate solution.

Products produced in parallel with ε-PeO (OH) can be used, for example, in the synthesis of tar dyes, in the production of agrochemicals, pharmaceuticals, photochemicals and can serve as semi-finished products for the production of other compounds; sulphate solutions can be used as they are obtained (ammonium sulphate as fertilizer, sodium and potassium sulphates as salting agents in chemical processes, possibly also as fertilizers) or can be converted to solid substances by evaporation of water.

An advantage of the process according to the invention is the possibility of producing o (* - PeO (OH) in the form of very fine particles of uniform grain size).

5 perfect homogenization of reactants.

225 4M

The process according to the invention can be carried out in a continuous manner, or? the chemical transformations are fast enough and the mixing of the components can be easily mechanized and automated. There are no special requirements for the reactors of conventional flow types - even from a corrosion point of view - which is a considerable advantage of this process.

A further advantage of the new process is the fact that at the isolation stage the wounded. The organic sulphates produced by the organic compounds 3e are used as salting-out agents, thereby increasing the proportion of separated organic substances and at the same time reducing their content in the remaining sulphate solutions.

The new process of production of oC-PeO (OH) can be carried out with minimal energy consumption, because the actual oxidation of green vitriol is exothermic and therefore reaction heat can be used to temper the reacting mixture. Also, the insulation of individual products relies on mechanical separations, so that energy-intensive operations such as distillation, solvent extraction distillation extraction, steam exaggeration and melting, which are otherwise common in analogous processes, are excluded from production.

In the accompanying drawings, Fig. 1 represents diffractometric records of both the product produced according to the invention (A) and pure eC-PeO (OH) (B). Giant. Figures 2 and 3 are electron microscope photographic images and represent © C-PeO (OH) produced by reaction between green vitriol and 1,3-dihydrobenzene-4-sulfonic acid in an ammoniacal environment. Giant. Figures 4 and 5 are electron microscopic photographic representations of α-PeO (OH) obtained by reaction between green vitriol and 4,4'-dinitrostilbene-2,2'-disulfonate sodium.

Example 1 mol of sodium m-nitrobenzenesulfonate is mixed with 2.5 l of water, the mixture is heated to 85 ° C and 450 ml of 25% aqueous ammonia and 834 g of green vitriol (PeSO4, 7 L) are added alternately in portions. The pH of the reaction mixture was 7 + 0.5 and the temperature during mixing was 80-90 ° C. After mixing, the suspension was stirred for a further 1/2 hour at 90 ° C.

The iron oxide is filtered off and washed with 300 ml of hot water; After drying at 100 ° C, 247 g of C 6 -PeO (OH) is obtained.

The mother liquors and washings were combined, acidified with 180 g of 30% H ₂ SO 4, cooled to 10 ° C, the precipitated methanilic acid was filtered off, washed with 200 ml of water at 5 ° C and dried; yield 146 g.

The remaining mother liquors contain 2.98 moles of ammonium sulfate and 0.49 moles of sodium sulfate.

In the case where 450 ml of 25% NH 4 OH was used in place, either

467 g of 30% NaOH or 186 g of soda ash, the yield of οό'-ΡθΟ (ΟΗ) is similar and a sodium sulphate solution is obtained in addition to methanilic acid,

If an ammonium salt is used in place of sodium pyrobenzenesulfonate, the residual mother liquors contain only ammonium sulfate.

Example 2 mol of p-nitrobenzoic acid is mixed with 2.5 l of water and neutralized by addition of 25% NH4OH. Using the procedure described in Example 1, the ammonium p-nitrobenzoate solution obtained was treated to ε -PeO (OH), p-aminobenzoic acid and ammonium sulfate solution under the reaction conditions.

The yield of eC -PeO (OH) is 247.5 g; p-aminobenzoic acid is obtained in a yield of 126.0 g and the yield of ammonium sulfate is 328 g. Example 3

270.2 g of 1,3-dinitrobenzene-4-sulfonic acid sodium salt as 86.3% paste is dissolved in 2.5 l of water and the solution is heated to 60 ° C. 450 ml of 25% aqueous ammonia alternately and 834 g of pure green vitriol (PeSO4, 7 HgO), so that the pH of the reaction mixture ranged between 7.5 and 8.5 and the temperature up to 60 ° C spa). The reaction mixture is then held at 65 ° C for 60 min. The solid iron oxide is filtered off and washed with 350 ml of hot water; after drying at 100 ° C, 249 g of eC-PeO (OH) are obtained. The diffractometric record (see Figure 1) revealed that the spectrum of sample (A) consists of a set of characteristic lines, of which the eight most prominent positionally coincide with the spectrum of pure oC-FeO (OH) (B) (literature: JOPDS (Joint Committee) on Powder Diffraction Standards) - 17-536; L, I.Mirkin: Righteous after X-ray analysic analysis of the Christians).

Measured by Cu _Ke £ · radiation

An electron microscope photographic recording at 20,000 and 60,000 magnification shows that the product analyzed consists of agglomerates of very fine particles (see Fig.

and 3) »

The analytically determined iron content (59.62%) and the annealing loss at 950 ° C (15.60%) are very close to the values for α 4 -FeO (OH) with an iron content of 62.85% and an annealing loss of 10.2

The combined mother liquors washed with water after isolation of the oxides were acidified at 30 ° C with 30% H 2 SO 4 to pH 3.5 _; After cooling to 5 ° C, the precipitated solid is filtered off and washed with 200 ml of water at 5 ° C; after drying, 198.4 g of nitroaminobenzenesulfonic acid (a mixture of isomers of 1-amino-3-nitrobenzene-4-sulfoacid and 1-nitro-3-aminobenzene-4-sulfoacid) is obtained. Mother liquors are essentially ammonium sulphate solution »

If 950 g waste green is used in place of 834 g pure green vitriol, vitriol (from titanium dioxide production) composition: 48,0% PeSO ₄ ; 0.2 to 0.7% TiO ₂ ; 1.0 to 1.5% MgO; 0.05% Mn; 0.03% Al 2 O 4 and 0.2 to 0.8% H 2 SO 4 gave virtually the same results.

Example 4

Following a procedure similar to that of Example 3, but with twice the amount of water (5 L) green vitriol (1668 g) and aqueous ammonia (500 mL), 500 g of α-FeO (OH) and 262 g of m-phenylenediamine sulfoacid were obtained. next to ammonium sulfate.

Example 5 4.4 mol ^*> -dinitrostilben 2,2 * -disulfonanu sodium are dissolved in 4.3 1 of water at 50 ° C, followed by concurrently adding a total of 450 ml 25% aqueous ammonia and 834 g FeSO ^ 7 H Alternately in portions so that the pH of the reaction mixture is maintained between 7.5 and 8.5 and the temperature at 85 ° C; after mixing the components, it is stirred for 1/2 hour at ~ ^β ~ 225 438 ° C, then the iron oxide is filtered off and washed with 350 ml of hot water. After drying at 100 ° C, 250.2 g of cC-FeO (OH) are obtained.

The diffractometric pattern corresponds to the spectrum of pure? -FeO (OH). Photographs of particles at 20,000 and 60,000 magnification show that they are very fine particles with dimensions below 1 µm (see Fig.

and 5).

The iron content (58.86%) is somewhat lower than that of pure α-FeO (OH) and the loss on ignition at 950 ° C is 16.30%, a little higher; found values indicate that the obtained << - FeO (OH) contains occluded water.

The mother liquors contain 0.985 mol of 4-nitro-4 ' -aminostilbene-2,2 ' -disulfonic acid, 0.493 mol of sodium sulfate and 2.99 mol of ammonium sulfate.

Example 6 moles of sodium 4,4'-dinitrostilbene-2,2'-disulphonate are dissolved in 7 l of water and at 50 ° C with concurrent addition of 900 ml of 25% aqueous ammonia and 1668 g of green vitriol at pH 8 + 0-, 5 and a temperature of 90 +5 ° C to prepare a mixture of ε-FeO (OH) ·, 4,4'-diaminostilbene-2,2'-disulfonic acid and sodium and ammonium sulphates; this mixture does. filtration, acidification and re-filtration.

The yield of? -FeO (OH) is 502 g, 4,4 &apos; -diaminostilbene-2,2 &apos; -di-sulfonic acid 315 g, sodium sulfate 0.492 mol and ammonium sulfate 4.98 mol.

Examples 7 to 12

By the experimental technique described in the above examples, the oxidation of green vitriol was performed by other nitro compounds, the specifications of which, together with the reaction conditions, are characterized by the following tabular overview.

i *

225 438

t - ¹ Γ0 l l t l 1 1 | 11 10 AND t 1 in I 1 1 what 1 AND 1 -4 1 1 1 and P < Hx řv * f-J • 1 with H 1 1 1 AND H 1 TO 1 1 H 1 H 1 1 P «4 ω P 1 1 the P 1 1 what 1 1 --4 1 what ά 1 Χ · 4 4χ P cl · £ 0 P P · P * p 1 P t t P t » d- O H P D 1 f-J cl · <4 P. the p. 1 the p. the Ρ · 1 P P * t-b P H · AND Hj P Pb d · P cl · J p cl · P d- 1 o o O O P 1 P O P P P 1 H P H P and ta n PV * P * O 1 3 σ ' O O Hj O 1 Hj O Hj O 1 Η Hx <4 P · P 1 1 H · Φ M Hj O P 1 O P O P 1 O the -> 1 pb P «4 CD 3 OJ 1 P anus P 1 P CD O 1 N » P Hj » «4 Hj «4 Hj l o < H P P 1 CD ΓΌ O the cl · 1 the cl · the cl · 1 Φ H · 1 P · 1 P 1 H Φ P 1 Φ P ω P 1 P P ΓΌ cl · 1 1 h- ¹ 1 H I- ¹ H H 1 H · • ί » AND P 1 4 = » H · CD 1 H · Φ H · Φ 1 P O 1 1 P P 1 P P P P l P l 1 1 1 P 1 AND 1 P 1 P 1 1 1 1 1 « 1 1 P Pi and 1 W • Pi 1 w Pi 1 HIM M 1 TO O w ro P řť P -F* 1 ø = x M · £ » Ω O px N < O 1 O 2 1 O w 1 (_I H. M 1 M 1 V * J H · C + 1 1 1 1 1 1 1 1 1 Φ px ro AND l ~ ^ 3 1 1 kO Γ 1 1 O 1 vn 1 O 4 1 d- a 1+ 1 1+ 1 P 1 φ Φ t O O 1 1+ P 1 * P p f-> Pi vn 1 vn 1 vn l 1 O O 1 1 o o < O 1 O Ω O 1 O 1 d- p Ω 1 AND 1 1 O 1 1 t 1 Ω 1 1 1 p Px Ί 1 AND 1 1 t 1 1 1 1 1 1 1 1 1 1 <4x VO AND vo VO vo 1 vo vo 1 tij c + —Ί vn F* - <] WHAT -4 1 CD CSC 1 w 1 1 O N < H 1 1 - <3 VJ vn 1 1 O O 1 1 z-x (D Oť 1 1 1 M 1 1 AND 1 1 t 1 H 1 1 t i.e hp r ^ T * H 1 » »- » q H řT H 1 1 <4 ΓΌ *and 1 -> l ^e 4 1 1 1 «4 1 N 1 -P 1 1 P * £ ω P 1 the P the P 1 P the 1 1 ra ^c 4 3 CD 3 l φ 3 CD 3 1 P · P pb 1 P P * H · AND-* H · 1 H · 1 — J H · 1 ív * H · 1 H P P H · P t H · P H · p 1 P Hj ffi t Hj O O P pj O 1 P O P O 1 C-J. O 3 with Hj P 1 P P P p 1 Hx řs * H · 1 3 <4 CD P 1 P P 1 O 4 P » Η » 1 P Hj 1 Hj Hj 1 Hx what O l p. ΓΌ O and cl · 1 t— ' cl · f-J cl · 1 CD P l AND t— ¹ Φ P 1 M P w P AND P H P 1 » P H * 1 • 4 t-> σ \ p-J 1 3 H · cl · 1 3 H · Φ 1 Φ Φ 1 P · P P AND H · P l O P Ω P 1 P P P 1 P 1 AND i— ¹ ! H 1 1 O O O WHAT 1 1 (Dx • 4 CDx cn 1 the P * AND σ ' 1 4 1 4 1 J H H · 1 CD the 1 Φ the Φ the 1 O P 1 P P 1 P P AND P O AND N t— ¹ »- » t— ¹ 1 o < P 1 CD Hj 1 Hj Hj 1 Φ l 1 P O 1 O O 1 P 1 | 1 1 1 1 1 p. 1 1 and P 1 1 1 F 1 1 1 P

-ΊΟExample 13 228 438

200 ml of water are introduced into a 1 liter glass stirred tank reactor, heated to 70 DEG C., and simultaneously the solutions of sodium metabenzenesulfonate, 87.0 g / l of solution, at a rate of 2.5 l / h, are simultaneously introduced. 25% aqueous ammonia at a rate of 0.45 l / h and at the same time green vitriol is added uniformly at a rate of 834 g / h. The temperature is maintained at 85 + 3 ° C by external reactor temperature control; The pH of the reaction mixture was maintained at 8 +0.5 by controlling the NH 4 OH feed or by adding green vitriol. The resulting slurry falls into a 85 ° C stirred tank, where it stays for an average of about 20 minutes, whereupon the discount! dC -PeO (OH) production is 241 g / h (weighed as dried product).

The mother liquors were not further processed in this case.

Claims (5)

A process for the preparation of α-EeO (OH) by a non-waste green vitreous process characterized by reacting aromatic mono- or dinitro compounds and solubilizing groups in the molecule and optionally other substituents consisting of alkyls, halogens, hydroxyls, alkoxy groups and NHg groups on aromatic nuclei, green vitriol and alkali metal, caustic earth or ammonium hydroxides or carbonates in an aqueous medium, preferably with the addition of surfactants, at temperatures between 30 ° C and the boiling point of the reaction mixture, The system maintains a pH of greater than 6.5, whereupon the solid oT-PeO (OH) is mechanically separated from the solution, from which the resulting amino compounds are precipitated with sulfuric, hydrochloric, nitric or phosphoric acid and after their mechanical separation a solution of inorganic salts with prevailing sulphate content, 2. Method according to claim 1, characterized in that green vitriol is used, which falls off the production of titanium dioxide or from the pickling of metallurgical materials. 3. The process according to items 1 and 2, characterized in that ammonia or an aqueous solution thereof is used to control the pH of the reaction mixture. 4. A process as claimed in any one of claims 1 to 3, wherein only the equivalent of green vitriol corresponding to one nitro group is reacted and the corresponding nitroamino compound is isolated from the reaction mixture, 5. Process according to any one of claims 1 to 4, characterized in that the reaction components are mixed in a continuous stirred tank reactor. 2 drawings