Deutsche Gold- Und Silber-scheideanstalt Vormals Roessler

Degussa Aktiengesellschaft

Werner Heimberger

Gerd Schreyer

Friedhelm Geiger

Theodor Lussling

Wolfgang Weigert

Hermann Schmitt

Friedrich Bittner

Kurt Puschner

Norbert Kriebitzsch

Martin Petzold

Kurt Henkel

Horst Hillenbrand

Johannes Heilos

Gerhard Bach

The residual gases obtained in the production of cyanuric chloride having a pressure of 1-5 bar (absolute) preferably 1-4 bar, are worked up by leading them into the lower portion of a column, reacted in the column with at least the equivalent amount of hydrogen cyanide to form cyanogen chloride and led in countercurrent flow to the water charged to the upper portion of the column whereupon the aqueous solution of cyanogen chloride formed is withdrawn from the lower portion of the column and preferably is returned into the production portion of the plant for recovery of the cyanogen chloride while the purified waste gas of the column leaves in the upper portion of the column.

Working up of the residual gases resulting from the production of

To obtain a cyanogen chloride which is practically free from water and preferably also free from hydrogen cyanide, hydrogen chloride and organic compounds, the crude cyanogen chloride is fractionally distilled. The return is led in countercurrent flow to the crude gas, thereby takes up the impurities and is further evaporated in the lower portion of the column, respectively in a special apparatus, by a liquid whose temperature is higher than the boiling temperature of cyanogen chloride. Thereby this liquid also takes up the impurities. The purification action is aided by a wash for the crude cyanogen chloride connected in series before it enters the fractionating column. It is very advantageous to combine the process with a plant for the production of cyanogen chloride.

Process for the recovery of pure cyanogen chloride

There is provided a process for the purification of ammonia or ammonium salt containing waste waters using alkali metal or alkaline earth metal hypochlorites comprising adjusting the waste water to an initial pH of 8-10.5 with an alkaline material and then treating the waste water with an alkali metal or alkaline earth metal hypochlorite in an amount practically equivalent to the ammonia or ammonium salt, in a given case while lowering the pH during the evolution of nitrogen by additional neutralization of this pH to about 6-8 whereupon only after the end of the evolution of nitrogen the pH of the waste water, if it deviates from 7, is adjusted to the neutral region in known manner. The initial pH is preferably adjusted with the help of an alkali or alkaline earth hydroxide, most preferably it is adjusted to a pH of 8-9 with the help of a buffer salt.

Process for the purification of waste water containing ammonia and

Cyanogen chloride or cyanogen bromide is prepared by reaction of hydrogen cyanide with hydrogen chloride or hydrochloric acid (or hydrogen bromide or hydrobromic acid) and hydrogen peroxide in aqueous medium in the presence of cupric and ferric ions under superatmospheric pressure, preferably between 1.5 and 16 bar, and the cyanogen chloride (or cyanogen bromide) recovered separated from oxygen and nitrogen. In a preferred form of the invention, the hydrogen chloride or hydrochloric acid is either partially or entirely formed directly in the recycling catalyst solution of cupric and ferric ions by reaction of chlorine and hydrogen cyanide, either with or without pressure.

Process for the production of cyanogen chloride using hydrogen peroxide

Finely divided solid cyanuric chloride is produced by feeding a jet of liquid cyanuric chloride into a separatory container, cooling the liquid cyanuric chloride with recycling inert gases to such an extent that the cyanuric chloride is separated in crystalline form, washing the thereby warmed cyanuric chloride vapor or dust containing gases free of cyanuric chloride in countercurrent flow with an inert liquid that is a good solvent for cyanuric chloride in a washing column connected to the outlet side of the separatory column, thus simultaneously cooling the gases, and subsequently again returning the gases to the separatory container, while the temperature of the cyanuric chloride containing washing liquid which has increased in the washing process is again brought to the original temperature by leading it in the cycle over a heat exchanger and spraying the inside of the pipe connected to the separatory container and leading to the washing column constantly with the washing liquid while dividing a partial stream of the cyanuric chloride containing washing liquid in a distillation column into pure liquid cyanuric chloride which is recycled into the separatory column and into pure washing liquid which is recycled into the washing column.

Process for the production of finely divided solid cyanuric chloride

Cyanogen is prepared by passing hydrogen cyanide together with hydrogen peroxide into a solution of copper(II) bromide, chloride, cyanide, nitrate, or sulfate containing ferric ions that is maintained at a temperature between 0.degree. and 100.degree. C.

Process of preparing dicyan

Cyanogen chloride and hydrogen chloride are produced by reacting hydrogen cyanide and chlorine, separating from the gaseous mixture on the one hand hydrogen chloride and on the other hand cyanogen chloride which in a given case can also contain chlorine, by absorption in a halohydrocarbon which has a boiling point between that of cyanogen chloride and cyanuric chloride and after distillative separation of the dissolved cyanogen chloride-chlorine mixture returning the solvent to the absorption column, the process includes

Process for the production of cyanogen chloride and hydrogen chloride

Cyanogen chloride is purified and the service life of activated carbon is increased in the subsequent trimerization of the cyanogen chloride to cyanuric chloride by process comprising reacting hydrogen cyanide with chlorine, in a given case in the presence of cyanogen chloride produced in the presence of water, which in a given case contains chlorine. The improvement comprises passing the cyanogen chloride over granular gamma aluminum oxide with an alkali metal or in a given case an alkaline earth metal content of 0 to 3 weight % at 20.degree.-100.degree.C., preferably 30.degree.-60.degree.C.

Process for the production of cyanogen chloride

Cyanogen chloride is purified and the service life of activated carbon is increased in the subsequent trimerization of the cyanogen chloride to cyanuric chloride by process comprising reacting hydrogen cyanide with chlorine, in a given case in the presence of cyanogen chloride produced in the presence of water, which in a given case contains chlorine. The improvement comprises passing the cyanogen chloride over granular commercial sodium aluminum silicate or a molecular sieve of the mordenite type, at 20.degree.-100.degree.C., preferably 30.degree.-60.degree.C.

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Hanau, Germany

Werner Heimberger