SU139680A1 - A method of making mineral paint "Moskovskaya krasna" A.S. Kozlova - Google Patents

Description

Basically auth. St. № 112347 and dependent auth. St. N ° 126970 described a method for obtaining a mineral paint (Moscow Red A.S. Kozlova) by precipitation from solutions of copper salts with potassium ferrocyanndium (sodium) in a weakly ammonia or neutral medium in the presence of an excess of ammonium salt.

In accordance with the proposed method, in order to reduce the consumption of ferrocyanide, the latter is synthesized from cyanogen, iron sulfate and soda ash in the form of a dilute solution, which is later used to precipitate copper salts from weakly acidic copper sulfate solutions containing an excess of ammonium sulfate.

The resulting precipitate of copper ferrocyanide by reaction with an aqueous solution of ammonia is converted into the double salt of copper and ammonium ferrocyanide (Moscow A.S. Kozlova).

With such a paint manufacturing method, the consumption of ferrocyanide is reduced by 20-25% due to an increase in the cyan-melt utilization ratio, while obtaining the ferrocyanide in the form of dilute solutions. At the same time, the operation of salting out solid ferrocyanide sodium (potassium) with sodium chloride and the unavoidable loss of ferrocyanide with mother liquors, as well as the processes of its filtration and drying, are eliminated.

Example. In an iron cylindrical reactor with a conical bottom (capacity 5.2 m), equipped with a mechanical stirrer and a supply of live steam, prevent 3.0 m of water (or wash water from washing the sludge) and 740-770 kg of 42% cyanine swim. After the termination of the release of acetylene into the reactor while the mixer is running, load 1 m of an aqueous solution containing 280-300 kz for 1 hour.

L 139680- 2 100% ferrous sulfate (FeSO4: 7Н2О) and heat the revavadion mixture for one hour at 60-70 °. Then, without turning off the agitators, 250-300 kg. Of 100% soda ash are loaded into the reactor and, after complete precipitation of calcium, the pulp containing 300 kg of Na4Pe (CH) b is filtered. The sodium ferrocyanide solution is collected in a collector, and the slurry is washed with water and returned, the washings are transferred to the reactor to dissolve the next portion of cyanoplast. The resulting solution of sodium ferrocyanide (5 m), at 40–50 ° and being stirred, is loaded into a second reactor (with a capacity of 10.2 m), into which 2 m of copper sulfate solution (250 kg of 100% CuSO4.5H20), 2 m of ammonium sulphate solution (700 kg of 100% (NH4) 2SO4) and 10-20 kg of vitriol oil (based on 100% H2SO4). Then, with continuous stirring, to the reaction mixture, having a temperature of 40-50 °, for 1 hour, 1 m of a solution containing 190-200 kg of 25% -H NH40H is added and the mixture is continued to move for 1 to 2 hours at 40 - 45 ° to the complete conversion of the red-brown precipitate of copper ferrocyanide Cu2Re (CN) b to the red precipitate of the double salt (HH4) 2 Scr (CN) b. Then, the stirring is stopped and the double salt is left in the mother liquor for 4-6 hours. After that, with stirring, neutralize 110–120 kg of sulfuric acid (vitriol oil) to a slightly alkaline reaction. After neutralization, the paint is filtered on a filter press, washed with water to the required content of soluble salts (0.5-3.0%) and either packaged in a paste form, or it exists at 60-70 ° and ground into a fine powder. The dry paint yield is 290-300 kg.

Subject invention

The method of manufacturing mineral paint (Moskovskaya Krasna A.S. Kozlov) according to the author's certificate No. 112347 and the author's certificate No. 126970, characterized in that, in order to reduce the consumption of materials and reduce the finished product, sodium ferrocyanide is synthesized from cyanoplast, sulphate of sulphate of iron sulphate in the form of a dilute solution, which is used as an intermediate in the precipitation of a weakly acidic solution of copper sulphate, containing an excess of ammonium salt, with the transfer of copper ferrocyanide sediment to double salt of ferrocyanide methium and ammonium ammonia solution.