GB183089A - Improvements relating to the neutralisation and drying of sulphate of ammonia - Google Patents

Abstract

183,089. Weyman, .G. Dec. 1, 1921. Ammonium sulphate.-Commercial ammonium sulphate is neutralized by the addition of a solid neutralizing-agent, preferably in powdered form, to the acid salt while it is being centrifuged. The neutralizing-agent, which should be one capable of evolving a gas when in contact with the warm salt, is preferably added after the bulk of the mother liquid has been expelled, and is introduced into the centrifuge so that it becomes spread on the inner surface of the crystals in the lower portion of the basket. The flow of the remaining liquor then disseminates the neutralizing-agent, or the gas evolved therefrom, throughout the mass. The salt is preferably discharged from the centrifuge before neutralization is complete, the continued decomposition of the reagent in contact with the hot salt serving to complete the process and, in addition, to dry the salt. The amount of neutralizing-agent required may be less than the theoretical. A centrifuge with means for distributing a neutralizing-agent in the basket thereof comprises a casing a, containing the basket b. The neutralizing agent is supplied from a worm feeder d, through a conduit e, the rate of feed cf the reagent being controlled by the turning of the handle g. Air under pressure may be blown in through the pipe f to facilitate the distribution of the reagent, which may be further distributed by means of chains k, attached to a ring l, so that they fly outwards, and also by means of the conical bottom h of the centrifuge.