STUDY OF THE EFFECTIVENESS OF ANTI-SCALANTS ON THE PROCESS OF CALCIUM SULFATE FORMATION
Rubrics: 1. CHEMISTRY
Authors:
1.
Mendeleev Univrsity of Chemical Technology
(Technology of inorganic substances and electrochemical processes, professor)
employee from 01.01.2002 to 01.01.2025
Mendeleev Univrsity of Chemical Technology (Technology of inorganic substances and electrochemical processes, professor)
employee
Moscow, Russian Federation
employee from 01.01.2002 to 01.01.2025
Mendeleev Univrsity of Chemical Technology (Technology of inorganic substances and electrochemical processes, professor)
employee
Moscow, Russian Federation
2.
RHTU im. D.I. Mendeleeva
(Tehnologii neorganicheskih veschestv i elektrohimicheskih processov)
graduate student from 01.01.2019 until now
Moscow, Russian Federation
graduate student from 01.01.2019 until now
Moscow, Russian Federation
Type:
Article
eLocation:
Status:
Published
Received:
07.08.2025
Accepted:
07.08.2025
Published:
07.08.2025
Language:
Russian
Keywords:
CALCIUM SULFATE, ANTISCALANTS, NUCLEATION, CRYSTALLIZATION
Abstract (English):
The process of sediment formation was studied using four groups of model calcium sulfate solutions with fourfold supersaturation (C(CaSO4) = 0.0598 mol/l) relative to the equilibrium concentration (C*(CaSO4) = 0.0145 mol/l) with the addition of antiscalants with a luminescent label as an example. The first and second groups of solutions contained an antiscalant based on the PAA polymer with the addition of phosphors F1 and F2 (PAA-F1 and PAA-F2), the third group contained an antiscalant based on HEDP organophosphonates with the addition of phosphor F (HEDP-F), and the fourth group contained an antiscalant based on PSI polyimides with the addition of phosphor NI (PSI-NI). A blank solution of calcium sulfate with fourfold supersaturation served as a comparison solution. Using complexometric and electrochemical methods of analysis based on different physical principles, kinetic dependences C(CaSO4) = f(τ), pH = f(τ), χ = f(τ) were obtained at temperatures of 25°C, 35°C and 45°C. Comparison of the curves allowed us to compare the efficiency of antiscalants by the duration of the nucleation period. It was found that the duration of the nucleation period estimated by conductometric methods of solution analysis is almost 2 times longer than the nucleation period estimated by the complexometric method of analysis. Presumably, this is explained by the adhesion of the inhibitor with the phosphor additive on the sensors, causing an error in measuring the values of specific electrical conductivity and pH, and, consequently, an erroneous interpretation of the data obtained. It has been shown that the antiscalants of the first and second groups (PAA-F1 and PAA-F2) are the most effective in the doses recommended by the manufacturers, ensuring the stability of solutions of fourfold supersaturation for over 91 days at T=25°C. Thermal instability of luminophores has been detected, leading to a significant decrease in their effectiveness and quantitative analysis error, which must be taken into account in each specific application. For the purpose of rational use, it is advisable to reduce the dose of antiscalants A1 and A2 recommended by the manufacturers.
The process of sediment formation was studied using four groups of model calcium sulfate solutions with fourfold supersaturation (C(CaSO4) = 0.0598 mol/l) relative to the equilibrium concentration (C*(CaSO4) = 0.0145 mol/l) with the addition of antiscalants with a luminescent label as an example. The first and second groups of solutions contained an antiscalant based on the PAA polymer with the addition of phosphors F1 and F2 (PAA-F1 and PAA-F2), the third group contained an antiscalant based on HEDP organophosphonates with the addition of phosphor F (HEDP-F), and the fourth group contained an antiscalant based on PSI polyimides with the addition of phosphor NI (PSI-NI). A blank solution of calcium sulfate with fourfold supersaturation served as a comparison solution. Using complexometric and electrochemical methods of analysis based on different physical principles, kinetic dependences C(CaSO4) = f(τ), pH = f(τ), χ = f(τ) were obtained at temperatures of 25°C, 35°C and 45°C. Comparison of the curves allowed us to compare the efficiency of antiscalants by the duration of the nucleation period. It was found that the duration of the nucleation period estimated by conductometric methods of solution analysis is almost 2 times longer than the nucleation period estimated by the complexometric method of analysis. Presumably, this is explained by the adhesion of the inhibitor with the phosphor additive on the sensors, causing an error in measuring the values of specific electrical conductivity and pH, and, consequently, an erroneous interpretation of the data obtained. It has been shown that the antiscalants of the first and second groups (PAA-F1 and PAA-F2) are the most effective in the doses recommended by the manufacturers, ensuring the stability of solutions of fourfold supersaturation for over 91 days at T=25°C. Thermal instability of luminophores has been detected, leading to a significant decrease in their effectiveness and quantitative analysis error, which must be taken into account in each specific application. For the purpose of rational use, it is advisable to reduce the dose of antiscalants A1 and A2 recommended by the manufacturers.
Keywords:
CALCIUM SULFATE, ANTISCALANTS, NUCLEATION, CRYSTALLIZATION
CALCIUM SULFATE, ANTISCALANTS, NUCLEATION, CRYSTALLIZATION
