Process for production of potassium silicate solutions by the addition of tempered quartz to hydrothermally reacted quartz and KOH, and hydrothermal reaction thereof

摘要

A process is disclosed for the hydrothermal production of potassium silicate solutions with high SiO.sub.2 :K.sub.2 O molar ratios, by the hydrothermal reaction of quartz sand with aqueous potassium hydroxide solutions at temperatures in the range of 150 to 300 C. at the pressures of saturated water vapor corresponding to these temperatures in a pressure reactor, which is characterized in that the potassium silicate solutions obtained thereby, which have SiO.sub.2 :K. sub.2 O molar ratios of less than 2.75:1, are then reacted with a quartz tempered at temperatures in the range of over 1100 C. up to melting point, the temperatures and pressures also being maintained in the ranges named.