Methods of treating silicious materials to form silicon carbide for use in refining ferrous material

Claim 2

A PROCESS FOR FERROUS METAL REFINING COMPRISING THE STEPS OF MIXING SILICON MATERIAL CONTAINING OXYGEN BEARING SILICON COMPOUNDS AND OXYGEN COMPOUNDS OF IRON WITH AT LEAST A STOICHIMETRIC AMOUNT OF CARBON TO COMBINE WITH THE OXYGEN BEARING SILICON COMPOUNDS IN THE MATERIAL TO FORM SILICON CARBIDE AND REDUCE OXYGEN COMPOUNDS OF IRON TO THE METALLIC STATE, HEAING THE MIXTURE IN A FIRST VESSEL IN A NONOXIDIZING AMOSPHERE TO A TEMPERATURE IN EXCESS OF 2500*F., HOLDING THE TEMPERATURE TILL THERE IS NO FURTHER REACTION BETWEEN THE OXYGEN BEARING SILICON COMPOUNDS AND CARBON, REMOVING THE RESULTING PRODUCT FROM SAID FIRST VESSEL, ADDING THE RESULTING PRODUCT TO MOLTEN FERROUS METAL IN A SECOND VESSEL, ADDING FERROUS SCRAP AND LIME FOR SLAG FORMATION TO THE MOLTEN METAL INJECTING HIGH VELOCITY JESTS OF OXYGEN GAS ONTO THE SURFACE OF THE MOLTEN FERROUS METAL TILL THE SILICON AND CARBON CONTENTS OF THE MOLTEN FERROUS METAL HAVE ATTAINED THE DESIRED LEVEL, ADDING FERROUS MATERIAL TO THE MOLTEN IRON IN AN AMOUNT SUFFICIENT TO MAINTAIN THE DESIRED FERROUS METAL POURING TEMPERATURE, SEPARATING THE MOLTEN SLAG FROM THE MOLTEN FERROUS METAL AND POURING THE RESULTING MOLTEN FERROUS METAL INTO MOLDS, TO CONVERT THE MOLTEN FERROUS METAL INTO SOLID FORMS.

Claim 3

A process as claimed in claim 1 in which the iron containing silicious material is heated with an excess of carbonaceous material above that stiochiometric amount necessary to form silicon carbide with the silicious material.

Claim 4

A process as claimed in claim 1 wherein a portion of molten ferrous metal is retained in the second vessel to form the molten metal and repeating the steps of the process beginning with the addition of the resultant product from the first vessel to the molten metal in the second vessel.

Claim 5

A process as claimed in claim 1 wherein the ferrous material added to maintain the desired pouring temperature is selected from the group consisting of ferrous scrap, prereduced iron, iron ore lumps, concentrate pellets and ore briquettes.

Claim 6

A process as claimed in claim 1 wherein the carbon is in the form of coking coal and the mixture is coked in the first vessel which is a coking furnace at a temperature in excess of 2500*F. in a non-oxidizing atmosphere generated by the partial combustion of the volatile matter released within the furnace by the coking of the coal.

Claim 7

A process as claimed in claim 5 wherein the coking furnace is a rotary hearth furnace.

Claim 8

A process as claimed in claim 5 wherein the coking furnace is a by product coking furnace.

Claim 9

A process as claimed in claim 5 wherein the coking furnace is a beehive coking furnace.

Claim 10

A process for ferrous metal refining comprising mixing silicious material with sufficient carbonaceous material containing oxygen bearing silicon compounds and oxygen compounds of iron to combine with the oxygen bearing silicon compounds in the silicious material to form silicon carbide and reduce oxygen compounds of iron to metallic iron, heating the mixture in a non-oxidizing atmosphere to a temperature in excess of 2500*F., holding the temperature till there is no further reaction between the oxygen bearing silicon compounds and carbon, grinding the resulting product to liberate the particles of metallic iron, removing the metallic iron magnetically, adding the non-magnetic residue to powered iron ore or iron ore concentrates, agglomerating the mixture, adding the resulting agglomerated product to molten ferrous metal, adding ferrous scrap and lime to the molten ferrous metal, injecting high velocity jets of oxygen gas onto the surface of the molten ferrous metal till the contents of the silicon and carbon have attained the desired level, adding ferrous metal the group consisting of ferrous scrap iron ore lumps concentrate pellets and mixtures thereof to the molten ferrous metal in an amount sufficient to attain the desired final ferrous metal pouring temperature, separating the molten slag from the molten ferrous metal, and pouring the resulting molten ferrous metal into molds, to convert it into solid forms.

Claim 11

A process for ferrous metal refining comprising mixing silicious material with sufficient carbonaceous material containing oxygen bearing silicon compounds and oxygen compounds of iron to combine with the oxygen bearing silicon compounds in the silicious material to form silicon carbide and reduce oxygen compounds of iron to metallic iron, heating the mixture in a non-oxidizing atmosphere to a temperature in excess of 2500*F., holding the temperature till there is no further reaction between the oxygen bearing silicon compounds and carbon, grinding the resulting product to liberate the particles of metallic iron, removing the metallic iron magnetically, adding the non-magnetic residue to powered iron ore or iron ore concentrates, agglomerating the mixture, adding the resulting agglomerated product to molten ferrous metal, adding ferrous scrap and lime to the molten ferrous metal, injecting high velocity jets of oxygen gas onto the surface of the molten ferrous metal till the contents of the silicon and carbon have attained the desired level, adding ferrous metal the group consisting of ferrous scrap iron ore lumps concentrate pellets and mixtures thereof to the molten ferrous metal in an amount sufficient to attain the desired final ferrous metal pouring temperature, separating the molten slag from the molten ferrous metal, and pouring the resulting molten ferrous metal into molds, to convert it into solid forms.

Claim 12

A process as claimed in claim 9 in which after magnetically removing iron from the processed iron containing silicious material the non-magnetic residue is ignited in air to burn out the carbon, the ignited residue than being agglomerated.

Claim 13

A process as claimed in claim 10 in which after igniting the non-magnetic residue in air, the resulting product is treated with one or more of the mineral acids consisting of sulfuric, hydrochloric, nitric or hydrofluoric acid of mixtures thereof to dissolve all of the non-silicon carbide constituents of the product, washing the product in water, decanting, filtering and drying product, agglomerating the dried produCt and adding the resulting product to molten iron.