DE377007C - Process for the preparation of urea from calcium cyanamide - Google Patents

Process for the preparation of urea from calcium cyanamide

Info

Publication number
DE377007C
DE377007C DEC28241D DEC0028241D DE377007C DE 377007 C DE377007 C DE 377007C DE C28241 D DEC28241 D DE C28241D DE C0028241 D DEC0028241 D DE C0028241D DE 377007 C DE377007 C DE 377007C
Authority
DE
Germany
Prior art keywords
calcium cyanamide
urea
preparation
cyanamide
calcium
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
DEC28241D
Other languages
German (de)
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
CHEM FAB VORM E SCHERING
ERICH FREUND DR
Original Assignee
CHEM FAB VORM E SCHERING
ERICH FREUND DR
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by CHEM FAB VORM E SCHERING, ERICH FREUND DR filed Critical CHEM FAB VORM E SCHERING
Priority to DEC28241D priority Critical patent/DE377007C/en
Application granted granted Critical
Publication of DE377007C publication Critical patent/DE377007C/en
Expired legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C273/00—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups
    • C07C273/02—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups of urea, its salts, complexes or addition compounds
    • C07C273/06—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups of urea, its salts, complexes or addition compounds from cyanamide or calcium cyanamide

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Description

Verfahren zur Darstellung von Harnstoff aus Kalkstickstoff. ,Gemäß Patent 23930g werden Harnstoffsalze durch Umsetzung von Kalkstickstoff mit Säuren dargestellt. Die Ausführung des Verfahrens setzt die Innehaltung gewisser Vorsichtsmaßregeln hinsichtlich Temperatur und Säurekonzentration voraus.Process for the preparation of urea from calcium cyanamide. ,According to In patent 23930g, urea salts are made by reacting calcium cyanamide with acids shown. The execution of the procedure implies the observance of certain precautionary measures in terms of temperature and acid concentration.

Es wurde nun gefunden, daß sich d-ie Bilclung von Harnstoff aus Kalkstickstoff glatt vollzieht, wenn man Kalkstickstoff nicht mit Säuren, sondern mit wäßrigen Lösungen von Metallsalzen unter geeigneten Bedingungen zur Reaktion bringt. In der Literatur findet sich zwar (Biochemische Zeitschrift 2G, 330/191o) die Angabe, daß durch Einwirkung wäßriger Aluminiumsulfatlösungen auf Kalkstickstoff wäßrige Cyanamidlösungen erhalten werden ;doch führt dieses Verfahren nur zur Bildung von Cyanamid mit seinen Polymeren als Nebenprodukten, während kein Harnstoff entsteht.It has now been found that the formation of urea from calcium cyanamide If you do not use calcium cyanamide with acids, but with aqueous ones Brings solutions of metal salts to reaction under suitable conditions. In the Literature can be found (Biochemische Zeitschrift 2G, 330 / 191o) the statement that by the action of aqueous aluminum sulfate solutions on calcium cyanamide, aqueous cyanamide solutions but this process only leads to the formation of cyanamide with its Polymers as by-products, while no urea is produced.

Es ist nun gelungen, Bedingungen aufzufinden, unter :denen aus Kalkstickstoff-unmittelbar Harnstoff erhalten wird. Wesentlich dafür ist, daß bei Temperaturen über 30° .gearbeitet und' die Konzentration d.e.r Metallsalzlösungen ihrer chemischen Natur in geeigneter Weise angepaßt wird. Voraussetzung ist die Verwendung solcher .Metallsalze, die unlösliche Hydroxyde bilden, wobei man vorteilhaft die zu ihrer vollständigen, Fällung notwendige Menge Kalkstickstoff anwendet. So liefern z. B. 2o prozentige Ferrisalzlösungen bei ioo° mit Kalkstickstoff in sehr .guter Ausbeute Harnstoff. Dabei geht die Geschwindigkeit der Harnstoflib- ildung der Zersetzung -des Kalkstickstoffes parallel, so daß nur (die Dauer der letzteren für :die Zeit der Operation entscheidend ist. Der Vorteil des Verfahrens liegt auch darin, daß trotz höherer Temperatur Dicyandiamicl oder Dicyandiamidin nicht auftritt. Beispiel: In ioo Liter e'ner 2o prozentigen Ferrisulfatlösung, die auf etwa ioo° geheizt und vom Rührwerk bewegt ist, werden 117 kg gepulverter Kalkstickstoff mit 43prozentigem Kalziumgehalt eingetragen. Nach etwa einer Stunde läßt .man abkühlen und saugt ab. Da die Menge des Kalkstickstoffes ausreicht, rum alles E_sen zu fällen, enthält das neutral reagierende Filtrat nur freien Harnstoff in nahezu reinem Zustande. Die eisenhaltigen Niederschläge vom Filterkönnen leicht wieder auf Ferrisalz verarbeitet werden,.We have now succeeded in finding conditions among: those from calcium cyanamide-directly Urea is obtained. It is essential for this that the work is carried out at temperatures above 30 ° and 'the concentration of the metal salt solutions of their chemical nature in a suitable Way is adjusted. The prerequisite is the use of such .metal salts that Form insoluble hydroxides, which are advantageous for their complete, precipitation using the necessary amount of calcium cyanamide. So deliver z. B. 2o percent ferric salt solutions at 100 ° with calcium cyanamide in a very good yield of urea. The speed goes here the urea formation of the decomposition of calcium cyanamide parallel, so that only (the duration of the latter for: the time of the operation is decisive. The advantage the process is also due to the fact that despite a higher temperature Dicyandiamicl or Dicyandiamidine does not occur. Example: In 100 liters of a 2o percent ferric sulfate solution, which is heated to about 100 ° and moved by the agitator, 117 kg are powdered Calcium cyanamide with a calcium content of 43 percent entered. After about an hour lets cool down and sucks off. Since the amount of calcium cyanamide is enough, rum To precipitate all of the iron, the filtrate, which reacts neutrally, contains only free urea in almost pure condition. The ferrous precipitates from the filter can easily processed again on ferric salt.

Claims (1)

PATENTANSPRUCH: `"erfahren zur Darstellung von Harnstoff aus Kalkstickstoff, dadurch gekennzeichnet, daß man wäßrige Lösungen von Metallsalzen, die unlösliche Hydroxyde bilden, auf Kalkstickstoff bei Temperaturen über 3o° einwirken läßt, wobei zweckmäßig so viel Kalkstickstoff angewendet wird, .daß eine vollständige Fällung der Metallsalze eintritt.PATENT CLAIM: `` "Learn about the representation of urea from calcium cyanamide, characterized in that one aqueous solutions of metal salts, the insoluble Form hydroxides, can act on calcium cyanamide at temperatures above 3o °, whereby expediently so much calcium cyanamide is used, that a complete precipitation the metal salts occurs.
DEC28241D 1919-08-05 1919-08-05 Process for the preparation of urea from calcium cyanamide Expired DE377007C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DEC28241D DE377007C (en) 1919-08-05 1919-08-05 Process for the preparation of urea from calcium cyanamide

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEC28241D DE377007C (en) 1919-08-05 1919-08-05 Process for the preparation of urea from calcium cyanamide

Publications (1)

Publication Number Publication Date
DE377007C true DE377007C (en) 1923-06-15

Family

ID=7018583

Family Applications (1)

Application Number Title Priority Date Filing Date
DEC28241D Expired DE377007C (en) 1919-08-05 1919-08-05 Process for the preparation of urea from calcium cyanamide

Country Status (1)

Country Link
DE (1) DE377007C (en)

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