Study of the infrared absorption spectra of various additive ashes

Conclusions

• 1. Study of ash IR spectra permits inferences as to the relative contents of sulfates, carbonates, oxides, and phosphates in the ash.

• 2. The concentrations of metals, phosphorus, and other elements in the additive ash depend strongly on the calcination method, and primarily on calcination temperature. At relatively low calcination temperatures, carbonates and oxides form along with the sulfates, as do phosphates if phosphorus is present in the additive. At high temperatures, the carbonate and phosphate concentrations decline. Acquisition of reproducible results therefore requires strict regulation and standardization of calcination conditions.

• 3. Additive-ash composition depends on the sulfur concentration in the oil in which the additive is dissolved.