Fixed alkali

Also found in: Medical.
(Old Chem.) a non-volatile base, as soda, or potash, in distinction from the volatile alkali ammonia.

See also: Fixed

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
Ammonium hydroxide, rather than a fixed alkali, is preferred to raise the pH to 9.2-9.5 because it is volatile and will not leave residue in the hair while processing.
reed) non-cellulosic polysaccharides in pulps resulted from increasing ethanol content in the pulping liquor from 20% to 60% (by volume), at a fixed alkali charge of 25%.