Heat sink formulation

A process for manufacturing a heat storage composition having a specific gravity from about 2.8 to about 4.0 and a volumetric heat capacity that is at least 50% higher than that of a pure clay, said composition comprising the steps of forming a mixture having the composition selected from the class consisting of:

• a) 50-95% oxide of iron and 50-4% of a mixture of clay, an organic binder or an inorganic binder, where said mixture can contain any portion of clay, organic binder or inorganic binder in any proportions provided the mixture adheres to the 50-4% compositional range,
• b) 50-85% oxide of iron, 10-2% of a transition metal oxide other than iron and 50-13% inorganic binder;
• and
• c) 50-80% oxide of iron, 15-5% of talc and 35-15% clay, wherein the oxide of iron is selected from the group consisting of FeO, Fe.sub.2 O.sub.3, Fe.sub.3 O.sub.4, hydrated iron oxide, higher oxides of iron and mixtures of such oxides;
• shaping said composition into a shape;
• and calcining said shape at a temperature and for a time sufficient to render the shape stable.

A process for manufacturing a thermal heat sink composition having a specific gravity from about 2.8 to about 4.0 and a volumetric heat capacity that is at least 50% higher than that of a pure clay, said composition comprising the steps of forming a mixture having the composition selected from the class consisting of:

• a) 50-95% oxide of iron and 50-5% of a mixture of clay, an organic binder or an inorganic binder or an inorganic binder other than clay, where said mixture can contain any portion of clay, organic binder or inorganic binder in any proportions provided the mixture adheres to the 50-5% compositional range,
• b) 50-85% oxide of iron, 10-2% of a transition metal oxide other than iron and 50-13% inorganic binder;
• and
• c) 50-80% oxide of iron, 15-5% of talc and 35-15% clay wherein the oxide of iron is selected from the group consisting of FeO, Fe.sub.2 O.sub.3, Fe.sub.3 O.sub.4, hydrated iron oxide, higher oxides of iron and mixtures of such oxides;
• shaping said composition into a shape;
• and drying said shape at a temperature and for a time sufficient to render the shape stable.