Synthesis of sodium A zeolite, useful e.g. in laundry detergent, involves dissolving valuable minerals in clay with hot aqueous sodium hydroxide solution, immediate quenching or dilution, filtration and stirring to precipitate product

摘要

In sodium A zeolite synthesis from clay, the valuable minerals are brought into solution in the hot NaOH solution. The solution is immediately chilled to lower temperature or diluted with water, then filtered to remove undissolved residue, stirred until zeolite is precipitated and finally filtered. In sodium A zeolite synthesis from clay, especially containing allophane and/or halloysite and optionally gibbsite as valuable minerals by treatment with aqueous sodium hydroxide (NaOH) solution at elevated temperature, the valuable minerals are brought into solution in the hot NaOH solution. The solution is immediately chilled to lower temperature or diluted with water, then filtered to remove undissolved residue, stirred until zeolite is precipitated and finally filtered.