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structural analogues with Hm−X−X−Hn bonding arrangements

‘This’ strong action of ‘salting’outylfot thehy- , ‘drogen ‘chloride makes it‘poslsible to vavoid ‘com-W
‘pl’e’tely the separation e; the‘ ‘nitric acid and the – evaporation‘ of ‘ the solutions obtained’, ‘by’ direct
“current ‘electrolysis >in”diaphragm cells. ‘ It is
” preferable’not to salt out thefproduct within the,» _ I cathode‘compartment of the cell, for thisfwould
disturb3 the- electrolytic‘ reduction, but to‘ per
“i’orm the “salting out in a special vessel. ‘Byrthe
*electrolysis ‘the electrolyte ‘in the’cell becomes
poor in’hydrogenchloride, partly by the migra
wously turning over thevcrystals. . ‘
tion of chlorine ions to the anode and the simul
taneous consumption of hydrogen ions at the
cathode for the reduction of nitric acid, partly by
the binding of hydrogen chloride to the hy
droxylamine freshly formed in the cathode com
partment of the cell. By the present process the
electrolysis is carried out to such an ‘extent that an electrolyte nearly saturated with hydroxyl
amine hydrochloride leaves the cathodev com partment of the cell. This electrolyte poor in
hydrogen chloride is now loaded in the vessel for
salting out, while cooling, with such an amount
of gaseous hydrogen chloride. as has previously
been consumed .in the electrolysis. A pure hy
droxylamine hydrochloride settles atthe bottom
of the liquid. The‘crystals formed are?ltered
and, in order to liberate them from the adhering
mother liquor, they may be washed with washing
lye ‘and water, whereby at once‘a pure market
able product is obtained. The washing, however,
is not absolutely necessary, as the adhering im-I
purities consist only of water,.hydrochloric ‘acid
and some nitric ‘acid._ When the productis care
fully dried these impurities may be evaporated
without decomposition ‘of the. hydroxylamine hy
drochloride. i It is possible, forinstance, to obtain
the moist product still containing mother ‘liquor
in a completely. pure and dry statefby heating it
for 1/2 to lhour to ‘about ‘50° C.., and simultane
The process has the advantage that the small
quantities of nitric acid‘ still contained vinthe
electrolyte do not‘ have to befseparated‘ by elec trolysis before the salting out.‘ ‘ ‘ ‘ ‘ ” ‘
The necessary quantity of nitric” acid, is added
to the mother vliquor remaining‘ ‘after‘the salting
out andthis liquor is then reconducted into‘, the
cathode‘ compartment of thefcell where’it‘is‘satu
rated”again ‘withtfreshlynvforrned hydrokylai’nine v hydrochloride. Thereby théfjcycie is‘c’lo’sedfior _ the main‘duantitjl of the‘ catholyte; ‘ ~ ‘ , A man‘ ‘ orti’on‘of ‘thegcatholyte; namely the
‘ increase ‘of volume‘ formediby Efjl’il’re washing ‘ lyjie,
‘ the addition‘ of’ni’tric a‘cid ‘a’ndisometimes by elec
tric osmosis; however;_ has-to ‘be-worked sepa ‘rately ‘from time meme; 301i course, theincrease
‘ of volume will be con?ned as miiph‘as‘ possibility
v‘avoiding or at- least sparingly’using ‘washing lye
‘ and by applying suitable diaphragm’s which “do
not’lend themselves to electric osmosis’iF‘ln [this
respect it is important ‘thatthfe quantity