Method for Improving the Durability of Carbon or Graphite Electrodes by Using Tio2 -Containing Products

Abstract

The invention relates to a method for producing carbon or HV graphite electrodes, in which a carbon carrier is mixed with a hydrocarbon-containing binder, and the mixture is subjected to a coking process and/or graphitization process, and one or more synthetic titanium compounds are additionally added to the raw materials. The titanium compound is preferably comprised of TiO2. Iron oxide can be added as an accompanying substance.

Description

In a preferred embodiment of the process, iron oxide, as well as the synthetic titanium compound, is added to the raw materials, it being possible for the iron to be in different oxidation states. The amount of iron oxide added is preferably up to 70 wt. % and particularly preferably 5 to 50 wt. % of the amount of synthetic titanium compound added. The iron oxide has a particle size d₅₀ preferably of 0.01 μm to 2000 μm and particularly preferably of 0.1 to 1000 μm.

An advantage of the process according to the invention is that the free pore volume of the electrodes is reduced by the refractory, finely particulate titanium compounds formed (e.g. TiC, TiN, TiCN). This advantageously reduces the attack of gases and liquid media on the electrode matrix and reduces the electrode consumption rate. Furthermore, the reduced pore volume can have an advantageous effect on the cracking behaviour of the electrodes. The reduced pore volume increases the density of the electrodes, advantageously reducing their resistivity. Any sulfur present is bound as FeS by the preferred addition of iron oxide.

Claims

1. A process for the production of a carbon or graphite electrode comprising mixing a carbon bearer with a binder comprising a hydrocarbon and subjecting the mixture to at least one of a coking or graphitization process, and introducing at least one synthetic titanium compound into said mixture.

2. The process according to claim 1, wherein the synthetic titanium compound is added to the carbon bearer, the binder or the mixture of carbon bearer and binder.

3. The process according to claim 1, wherein an electrode is impregnated with the synthetic titanium compound is added to tar pitch, and the tar pitch to which the synthetic titanium compound has been added.

4. The process according to claim 1, wherein the synthetic titanium compound comprise TiO2.

5. The process according to claim 1, wherein the synthetic titanium compound is provided in a mixture comprising a companion substance.

6. The process according to claim 5, wherein said comparison substance is at least one of substances iron oxide, silicon oxide, calcium oxide or magnesium oxide.

7. The process according to claim 1, wherein the synthetic titanium compound is added to the raw materials in a proportion of 0.5 to 30 wt. %, calculated without any companion substances and based on the total weight of all the raw materials.

8. The process according to claim 1, wherein the synthetic titanium compound has a preferred particle size d50 of 0.001 μm to 2000 μm.

9. The process according to claim 5, wherein iron oxide is added as the companion substance.

10. The process according to claim 9, wherein the amount of iron oxide added is 5 to 50 wt. % of the amount of synthetic titanium compound added.

11. The process according to claim 9, wherein the iron oxide is added in an amount of up to 70 wt. % of the amount of the synthetic titanium compound.

12. The process according to claim 9, wherein the iron oxide comprises iron having different oxidation states.