Calumite is used in all types of soda-lime-silica glass production. The level of Calumite usage depends on factors such as glass colour, glass composition and local raw materials. The level of Calumite is usually expressed as a percentage of the dry sand weight.
In float glass, Calumite is typically used at 4 to 8% of the dry sand weight. In container glass the amount of Calumite varies with the colour of the glass being produced, from 4% for cosmetic flint production to 30% of the dry sand weight in amber glass. In fibre glass the level is typically 11% of the dry sand weight and in glass bulbs and tubes 4%.
Use of Calumite requires adjustments to the batch depending on the raw materials currently being used. Typically, use of Calumite would reduce the amount of limestone, dolomite and also alumina source such as nepheline syenite or an alkali feldspar. In many cases it is possible for Calumite to be the sole alumina source, often simplifying the batch recipe.
Calumite Limited and Calumite S.R.O. both employ experienced glass technologists to work with customers to maximise the benefits that can be achieved by using Calumite. We have wide experience of implementing Calumite in many different glass furnaces around the world. We are able to offer advice with batch and redox calculations when determining the different stages of Calumite implementation and offer on-site technical support for the duration of a trial and beyond. Our knowledge of furnace operation, glass quality and colour analysis ensure a smooth transition to using Calumite.