Patent ID: 11905218
Assignee: REFRACTORY INTELLECTUAL PROPERTY GMBH & CO. KG
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  F | IPC C  F

Claim 12:
13. A method for the production of a product comprising the following steps:
providing a batch, where the batch is for producing a refractory product, the batch comprising the following components:
a first raw material component, consisting of grains of magnesia;
a second raw material component, consisting of coated grains, comprising the following features:
the coated grains have a grain size of at least 2 mm;
the coated grains consist of magnesia, the surface of which has a coating of alumina at least in sections;

shaping the batch into a shaped unfired refractory product;
firing the shaped unfired refractory product into a shaped fired refractory ceramic product, the shaped fired refractory product comprises the following features:
the shaped fired refractory ceramic product has a chemical composition according to which the following oxides are present in the following proportions:
MgO: at least 92% by mass;
Al2O3: 1.5 to 7% by mass;
Fe2O3: less than 3% by mass;
CaO+SiO2: 1 to 3% by mass;

the shaped fired refractory ceramic product comprises the coated grains having the following features:
the coated grains have a grain size of at least 2 mm;
the coated grains consist of magnesia, the surface of which has a coating of magnesia spinel at least in sections; and
the coating of magnesia spinel having a thickness in the range from 10 to 500 μm.