Boiler descaling agents are primarily compounded from alkali and alkaline substances, with the finished product being a pale red or white powder. Inside the boiler, they undergo a chemical reaction with sulfate and silicate scale, forming carbonates. This is the principle by which the descaling agent transforms the hard and difficult-to-remove sulfate scales into loose ones. The transformed carbonate scales are insoluble in water, but during the transformation, they will either fall off the pipe walls or become crumbly and dispersed, being decomposed by the tannin substances in the descaling agent.

Sludge, easily removable by hand or mechanical means, to achieve the descaling purpose.