THE STUDY OF THE PRECIPITATE FORMATION PROCESS IN SILICATE-ALKALI MIXTURE IN THE PRESENCE OF SALT WATER

Autor: Оlga Titova, Natalia Stoliarova, Zoia Hrushak, Tetiana Kravchuk
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Vìsnik Nacìonalʹnogo Avìacìjnogo Unìversitetu, Vol 75, Iss 2, Pp 75-82 (2018)
ISSN: 2306-1472
1813-1166
Popis: Purpose: The aim of this article is investigation of the precipitation process when diluting silicate solution with salt water. The precipitation process changes have been analyzed with pH value increasing of the initial silicate-alkali mixture. Methods: Methods of direct and reverse titration were used for the determination of silicate relative concentration in the supernatant liquid. pH metrics was used for determination pH value change of silicate-alkali mixtures during experiment performance. Results: the precipitation process proceeds more intensively when ratio of silicate and salt water is 40 ÷ 60; the precipitate amount consistently decreases with pH value increase in initial mixture in the result of mixing with salt water; necessary residue concentration of silicate in a solution should be 1.5-2 mass % for a gel formation process; the most significant changes of mixture pH values occurs when salt water content is above 50 %. Discussion: It is necessary to determine silicate concentration in the supernatant liquid (filtrate) for the determination minimal silicate concentration necessary for gel formation when mixing silicate mixtures with salt water. It was determined that silicate amount in the supernatant liquid increases for all ratios of silicate and salt water with pH value increase in the initial mixture, besides it is necessary to increase part of salt water in a mixture with pH value increase for obtaining the same concentration of silicate in the supernatant liquid. It was found, that gel formation (for a mixture with initial pH = 11.72) occurred at silicate residue concentration in the solution equal to 0.25-0.3 from the initial one. Thus, it was found that minimal silicate concentration in a solution may be 1.5-2.0 mass %.
Databáze: OpenAIRE