RU1789509C - Method of producing manganese carbonate - Google Patents

Abstract

The invention relates to methods for producing carbonic manganese used to produce high quality manganese-zinc ferrites. Manganese carbonate is obtained from wastewater produced by hydroquinone by treating wastewater in the presence of ammonium persulfate in an amount of 2.0-3.0 wt.% Of the mass of manganese contained in the solution and pH 6.5-7.0, filtering the resulting mixture with subsequent separation of the solution and its treatment with aqueous ammonia in the presence of hydroxylamine sulfate, exposure of the resulting suspension, separation of the mother liquor from manganese-containing precipitate, recovery of the precipitate with sulfuric acid to pH 6.0-6.5, exposure of the resulting suspension, sample Botko with aqueous ammonia to a pH of 8,6-9,0 with the separation of the manganese-containing precipitate, dissolving the precipitate in the sulfuric acid treatment of the resulting solution of ammonium carbonate with further isolation, washed and dried title product. 1 tab. ё

Description

The invention relates to methods for producing carbonic manganese used to produce high quality manganese-zinc ferrites.

A number of methods are known for processing manganese-containing effluents resulting from the oxidation of aniline in the production of hydroquinone.

A method for producing manganese carbonate from wastewater from the production of hydroquinone consists in purifying a solution of manganese sulfate from iron, heavy metals, organic impurities, followed by treating the solution with barium fluoride paste to remove calcium and precipitating manganese carbonate with ammonium carbonate.

The disadvantage of this method is the increased content of calcium and magnesium impurities in the final product.

Closest to the claimed is a method for producing manganese carbonate from aniline oxidation products.

The essence of the method consists in the fact that a solution of manganese sulfate, which is a waste product, is preliminarily purified from iron by oxidation

(O-t-T

Fe in Fe with H202 from heavy metals with a solution of ammonium sulfide from organic impurities by treatment with activated carbon. Purification from alkali and alkaline earth metals is carried out by treating with an aqueous solution of ammonia to a pH of 8.6-9.0 at 50-70 ° C in the presence of hydroxylamine sulfate,

-VI

oo

ABOUT

ate about

exposure of the suspension, separation of the contaminated mother liquor from the manganese-containing precipitate, its subsequent repulpation with sulfuric acid to pH 6.0-6.5, exposure of the suspension, treatment of the suspension with aqueous ammonia to pH 8.6-9.0, followed by separation of the precipitate and dissolving it in sulfuric acid and treating it with a carbon ammonium salt, followed by washing and drying the precipitate.

The disadvantage of this method is the relatively low yield of the target product (80%), associated with the loss of manganese during purification.

The purpose of the invention is to increase the yield of the target product and simplify the process.

This goal is achieved in that carbonic manganese is obtained from wastewater, a waste product of hydroquinone production, by adding to the initial solution containing manganese sulfate in an amount of 230-250 g / dm, ammonium persulfate in an amount of May 2-3. % with respect to the manganese contained in the solution and the reaction pH in the range of 6.5-7.0, followed by purification from organic impurities, alkali and alkaline earth metals, precipitation from a purified solution of manganese carbonate with a solution of carbon ammonium salt, followed by washing and drying of the product.

- An example. A glass with a stirrer is placed in a thermostat, pour 1 liter of wastewater containing manganese sulfate. The concentration of the solution was adjusted with distilled water to 230 g / dm3.

15 g of activated carbon are loaded into the solution. By supplying an aqueous solution of ammonia, the pH was adjusted to 6.5. The solution is heated to a temperature of 70 ° C, 1.7 g of ammonium persulfate are added, which corresponds to May 2. % with respect to manganese in solution, while the suspension takes an acidic reaction (pH 3). Raise the pH value to 6.5-7.0 by adding an aqueous solution of ammonia, maintain the contents of the glass for 1 h at a temperature of 60-80 ° C and filter ..

To prevent oxidation of Mn + 2 to Mn + and Mn +, 2.0-2.5 g of hydroxylamine sulfate is added before ammonia precipitation. By supplying ammonia, the pH was adjusted to 8.6-9.0, heated to 60 ° C and held for 1 hour to form basic manganese salts. The precipitate is wrung out, transferred to a beaker with a stirrer, 1-1.5 g of hydroxylamine sulfate is added, it is poured with distilled water () and stirred for 10 minutes.

Sulfuric acid is metered into the suspension to a pH of 6.0-6.5, maintained for 0.5 hours, then the pH is adjusted to 8.6-9.0 with ammonia and held for 1 hour, after which the precipitate is squeezed and

subjected to two washes.

The washed and squeezed precipitate is stirred with water (0.7-0.75) dm3 and dissolved in sulfuric acid. When the pH of the solution reaches 3.0-4.0, the acid supply is stopped, the solution is cooled to 25 ± 5 ° C and carbonic manganese is isolated from it with a solution of ammonium carbonate (340 ± 40) g / dm3. The precipitate is squeezed out and washed with distilled water until there are no sulfates in industrial waters and dried in an oven at a temperature of 70-90 ° C to a mass fraction of manganese of 43-45%.

The yield of the finished product is 90%.

The effect of the amount of introduced ammonium persulfate on the purity of manganese carbonate and the loss of manganese are given in the table.

Example. Manganese synthesis completed

carbon dioxide from wastewater produced by hydroquinone with varying amounts of ammonium persulfate additive. The data obtained are also given in the table.

As can be seen from the table of the prototype

(see Example 1) samples were obtained that meet the requirements of TU, and the loss of manganese in the sludge at the stage of purification from heavy and easily hydrolyzable metals was 10-13 wt.%. Total losses are higher due to

losses at the stage of cleaning from alkaline and alkaline earth elements.

In Example 2, the addition of 1% ammonium persulfate was insufficient to completely remove the heavy metals. Examples

h-4 indicate a sufficient amount of ammonium persulfate to purify the manganese solution at the requirements of TU of the target product and a significant reduction in the conversion of manganese to sludge.

A further increase in the amount of ammonium persulfate (Examples 5-6) leads to an increase in manganese losses and consumption of ammonium persulfate without significantly improving the quality of the target product.

at a pH of precipitation of impurities outside the optimal range (Examples 7-8), either nickel, copper, zinc and lead are not sufficiently purified (see Example 7) or losses of manganese due to the formation of its hydroxides increase (see Example 8).

Thus, the use of the claimed method will allow, in comparison with the prototype, to increase the yield of the target product and to obtain high-quality manganese-zinc ferrites used in electronic technology, as well as the process by reducing the number of filtration stages and combining the processes of purification from easily hydrolyzed, heavy metals and organic impurities in one process. The claimed method excludes the use of toxic (NH4) 2S and explosive spare N262.

Formula A method for producing manganese carbonate from wastewater of hydroquinone production, including purification of wastewater from lightly hydrated and heavy metals, filtering the resulting mixture, followed by separation of the solution and processing its aqueous ammonia solution in the presence of hydroxylamine sulfate, aging the resulting suspension, separating the mother liquor from the manganese-containing precipitate, repulping the precipitate with sulfuric acid to a pH of 6.0-6.5, holding the resulting suspension, treating it with an aqueous solution f additives of ammonium persulfate and the pH of the solution on the quality of the obtained carbonic manganese and loss of manganese at the stage of wastewater treatment from lightly hydrolysing and heavy metal

Note: Wastewater produced by hydroquinone has the following composition, May. %:

manganese sulfate 24.71; sulfuric acid 1.58; pyrolusite 0.14 ammonium sulfate 3.58; impurities of 1.42; quinone 0.10; calcium sulfate 0.32; water the rest.

ammonia to pH 8.6-9.0 with separation of the manganese-containing precipitate, dissolving the precipitate in sulfuric acid, treating the resulting solution with ammonium carbonate with further isolation, washing and drying of the target product, characterized in that, in order to increase the yield of the target product and simplify of the process, wastewater from light hydrolyzing and heavy metals is carried out in the presence of ammonium persulfate in an amount of 2.0-3.0 wt.% of the mass of manganese contained in the solution and pH 6.5-7.0.