process for the treatment of an aqueous solution of formaldehyde concentration to obtain, at the same time, a solid polymer of formaldehyde.and a solution to control of formaldehyde concentration.

摘要

Solid formaldehyde polymers are prepared by introducing into a concentrated aqueous solution of formaldehyde, the pH of which has been adjusted to from 9 to 10, 20 to 75% of a formaldehyde polymer (based on the formaldehyde present in the solution), keeping the temperature of the mixture at from 20 to 40 DEG C. to polymerize the formaldehyde and then separating the solid polymer from the aqueous solution obtained which has a formaldehyde content of from 29 to 40%. A part of the solid polymer formed may be used as the added polymer. Caustic potash may be used to adjust the pH. Apparatus for carrying out the process, which may be continuous or discontinuous is described.