Solvay Chemicals Gmbh

David W Smith

James D Phillip

Jessica A Mote

Alain Vandendoren

Ronald O Hughes

Jessica A Motte

A method for removing impurities from a waste solid to provide at least a portion of a suitable crystallizer feed to a process for making crystalline sodium carbonate, bicarbonate, and/or other derivatives. The method comprises: contacting the waste solid with a leach solution to dissolve at least one impurity and dissolving the resulting leached residue. Leaching may include heap percolation. The leach solution may comprise a crystallizer purge liquor, a process waste effluent, a mine water, or mixtures thereof. The method may further comprise adding a magnesium compound to the resulting leached residue during or after its dissolution to remove another impurity. The waste solid preferably comprises a pond solid containing such impurities. The pond solid may be recovered from a pond receiving crystallizer purge liquor(s) and/or other process waste effluent(s). The pond solid may contain sodium carbonate, any hydrate thereof, sodium bicarbonate, and/or sodium sesquicarbonate. The impurities to be removed may comprise sodium chloride, sodium sulfate, silicates, and/or organics.

Impurities removal from waste solids in the production of soda ash, sodium bicarbonate and/or other derivatives

A magnesium treatment for removing water-soluble impurities in a process for making crystalline sodium carbonate, bicarbonate, or sulfite. A waste comprising such impurities is treated with a magnesium compound to form water-insoluble matter which is removed to form a purified solution. The treatment may be performed on a solution which contains the waste and optionally dissolved calcined trona. The purified solution may be used as a feedstock to form crystalline soda ash, and/or used as a reactant to produce crystalline sodium sulfite or bicarbonate via reaction with SOor CO. In preferred embodiments, the waste may comprise a purge or weak liquor, a reclaimed solid, or combinations thereof. The water-soluble impurities may be silicates and/or foam-causing impurities, and the waste may contain sodium bicarbonate, sodium sesquicarbonate, and/or one or more sodium carbonate hydrates, such as decahydrate.

Growing community of inventors

Rock Springs, WY, United States of America

David W Smith