PROCESS FOR RECOVERY OF NITRIC ACID FROM WASTE NITRIC ACID AND/OR NITRATE

摘要

A process for recovery of nitric acid comprising incorporating or absorbing waste nitric acid and/or a nitrate in an oil-absorbing inorganic carrier and forming a nitrate-carrier granule containing water in the form of a hydroxide, a hydrate or adsorption moisture in an amount sufficient to generate a vapor of nitric acid stably and being substantially non-sticky at decomposition temperature of the nitrate; heating the formed granule while keeping the substantially non-sticky state in the granule to decompose the nitrate in the granule to a vapor of nitric acid; and recovering the generated vapor of nitric acid is disclosed. According to this process, nitric acid can be directly recovered from waste nitric acid or a nitrate in the form of a vapor of nitric acid without substantial generation of nitrogen oxide gases by using a cheap and easily available inorganic carrier.