Process for producing boron compounds from borate ores
OwnerStephen I. Sallayinventor
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Abstract
High purity ammonium pentaborate or boric acid is produced from alkali metal and alkaline earth metal borate ores by a relatively non-corrosive technology requiring low energy, without polluting the environment, by treating finely ground borate ores with ammonia and sulphur dioxide or ammonium sulphite in the presence of methanol. Useful by-products, such as sulphites, or fertilizers, such as ammonium phosphates, can be obtained. If the ore is rendered anhydrous prior to treatment, there is produced methylborate-ammonia adduct which upon hydrolysis is transformed into ammonium pentaborate and boric acid.
Claims15
A process for producing purified ammonium pentaborate from a finely ground alkali metal or alkaline earth metal tetraborate ore, comprising contacting said ore with ammonium sulphite in the presence of methanol and sufficient water whereby the trimethylborate-ammonia adduct intermediate formed hydrolyzes into ammonium pentaborate, separating the resulting methanol solution of said ammonium pentaborate from the concurrently formed methanol-insoluble alkali metal or alkaline earth metal sulphites and gangue, and recovering said ammonium pentaborate from said solution.
A process for producing trimethyl borate-ammonia adduct from a finely ground anhydrous alkali metal or alkaline earth metal borate ore, comprising contacting said ore with ammonium sulphite in the presence of methanol and recovering said adduct from the reaction mixture.
Dependencies are inferred from the claim text.