Specification of William Edward Newton : preparing hydrate of magnesia.

  • Newton, William Edward.
Date:
1874
Catalogue details

Licence: Public Domain Mark

Credit: Specification of William Edward Newton : preparing hydrate of magnesia. Source: Wellcome Collection.

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    Newton's Improved Process for Preparing Hydrate of Magnesia, Where liquor ammonice fortior containing some twenty-six and one half per cent, of ammonia is used from thirty to forty pounds will be found amply sufficient for the purpose ; but when simple liquor ammonise is used containing about ten and a half per cent, of ammonia it will take from two to three times as many pounds to produce the 5 same result. In each case however sufficient should be used to insure the thorough precipitation of the magnesia, and for this purpose it is better to dilute the ammonia with a sufficiency of water to prevent evaporation before it combines with the sulphuric acid of the magnesia. The materials above mentioned having been thoroughly mixed with 10 each other they may, if desired, be subjected to heat through the aid of steam in the manner employed and described in the Specification of the Patent above referred to. Whether or not heat be used sufficient agitation must be employed to prevent the coagulation of the magnesia on the bottom and sides of 15 the vessel. When this has been done the solution and mixture may be allowed to settle, as a rule twenty-four hours, or thereabouts, will be found amply sufficient for the purpose. The clear liquor containing a portion of the resultant sulphate of ammonia is then drawn off, and more distilled water added in quantity sufficient to replace the liquor 20 withdrawn, and the mass is agitated for ten minutes to half an hour, and again allowed to settle, when it may be drawn off as before. This operation may be repeated for three or four times more when it will be found sufficiently pure for the purpose desired. The sulphate of ammonia being much more easily removed by washing 25 than the resultant solution of the sulphates of soda and potash of the aforesaid patented process, the use of ammonia materially lessens the time, labor, and expense of the process. Or instead of simply using cold water for the washing process, heat with agitation may be employed either in the form of steam, or in any 30 other suitable form, in which case the boiling may be sufficiently prolonged during one or two washings to entirely expel the sulphate of ammonia, thereby leaving nothing behind but the hydrate of magnesia (in its pure form) suspended in the water; but if desired it may be >vashed once or twice more to insure the utmost purity of the product. 35