The chemical composition requirements of Molaisha are as follows:

I. Main components

Alumina (Al₂O₃): The content is usually between 42% and 77%. For example, the ALO content of Molai sand powder is generally 42%-46%, and the ALO content of sintered mullite (SM series) is 57%-77%.

Silicon dioxide (SiO₂): The content is generally between 51% and 53%. The SiO₂ content of sintered mullite ranges from 23% to 30%.

Mullite phase content: Mullite phase is the main crystal phase of Molaisha, and its content is usually not less than 75%. The mullite phase content of sintered mullite should be ≥80%-90%.

II. Impurity components

Iron oxide (Fe₂O₃): The content is usually controlled at 0.5%-1.5%.

Sodium oxide (Na₂O) and potassium oxide (ko): the total content is generally not more than 0.3%-0.5%.

Calcium oxide (CaO) and magnesium oxide (MgO): The total content usually does not exceed 0.6%-1.5%.

Titanium dioxide (TiO₂): The content is generally not more than 0.1%-0.5%.

III. Other indicators

Refractory: The refractoriness of Molaisha is usually not lower than 1750℃.

Bulk density: generally, it is required to be ≥ 2.5g/cm.

Water content: usually not more than 0.03%.

Ignition loss: generally not more than 0.3%-0.4%.

PH value: usually between 7 and 9.

IV. Testing standards

The detection of chemical composition of Molaisha is usually carried out according to GB/T 6900 or GB/T 21114 standards. These standards ensure that the chemical composition of Molaisha meets the requirements of industrial application.