Determination of silica in boiler water - Database & Sql Blog Articles

Determination of Silica in Boiler Water

The determination of silica in boiler water is a critical process used to monitor and maintain the quality of water in industrial boilers. This method typically involves spectrophotometry, specifically using the silicon molybdenum blue technique with a UV-1200 spectrophotometer. The procedure is based on the reaction between soluble silica and ammonium molybdate under acidic conditions (pH 1.2–1.3), forming a yellow complex that is then reduced to a blue compound. The intensity of the blue color is directly proportional to the silica concentration in the sample. To ensure accurate results, several reagents are required, including ammonium molybdate, stannous chloride, sulfuric acid, sodium silicate, and sodium carbonate. The process also requires careful preparation of standard solutions, calibration curves, and precise handling of samples. Safety precautions must be followed when working with chemicals such as concentrated acids and molybdate solutions. During testing, a 50 mL colorimetric tube is used to prepare both the standard curve and the sample. After adding the appropriate volumes of reagents and allowing the reactions to proceed, the absorbance at 720 nm is measured. This data is then used to calculate the silica content in the water sample. It's important to maintain consistent temperature conditions during the analysis, as variations can affect the accuracy of the results. Additional notes include the importance of cleaning all glassware thoroughly before use, ensuring that the temperature of the sample and standards do not differ by more than ±5°C, and properly storing reagents to prevent degradation. The entire process is well-documented and widely used in water treatment and industrial chemistry laboratories.