Properties and structures of Sodium silicate – sand mixtures components

Abstract

Article is devoted to the questions of structuring regularities detection in sodium silicate – sand mixtures and possibility of forecasting and changing their properties determination. Studies have been performed using quartz sand and sodium silicate solute, and also quartz sand placket with sodium silicate solute. It has been discovered that sand flow ability does not depend on the size of its particles, and the largest value acquires with the content of free water (moisture) less than 0.2% by weight. It has been established that apparent density of rare and placket sand, compacted by vibration, is additive to fractional mass content in it of particles normalized fractions and increases from 1100 to 1900 kg/m3 with average size of its grains decreasing from 0.82 to 0.16 mm and with their fineness modulus increasing from 20 to 60. According to experimental data, analytical relationship between content of sodium silicate in sodium silicate solute and specific density of sodium silicate solute has been elaborated. Estimation of sodium silicate solute drying method influence on residual water content in it has been realized. It has been shown that depending on sodium silicate solute amount in mixture, its physical state up to the time of mixture structuring beginning and method of solidification, the structure of solidified sodium silicate solute in structured sodium silicate – sand mixture may vary from dense-oriented to foam-disoriented, contain or not contain residual water. Obtained data using and recording will allow not only reduce the cost of new sodium silicate – sand mixtures developing, increase prediction of their properties accuracy, but also open a new direction for methods of their implementation in foundry molds and rods production.