Method for removing chrome and/or nickel from liquid slags
AssigneeHolcim Ltd.
InventorAlfred Edlinger
Life of this patent
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Abstract
In a method for dechroming and/or denickelifying liquid slags or slag mixtures, in which the liquid slag is charged onto a metal bath, in particular an iron bath, and reduced by feeding carbon or carbon carriers, the carbon feed into the metal bath is effected until a decrease of the Cr and/or Ni oxide contents of the slag to a value of between 0.8 wt.-% and 0.2 wt.-%. As the pregiven Cr oxide content range of the slag is reached, reductants having higher reduction potentials such as, e.g., Al, Ca, Si, Fe—Si or Ca—Si are added in order to lower the Cr and/or Ni oxide contents to below 0.15 wt.-%, preferably below 0.08 wt.-%.
Claims4
A method for dechroming and/or denickelifying liquid slags or slag mixtures, in which the liquid slag is charged onto a metal bath, in particular an iron bath, and reduced by feeding carbon or carbon carriers, characterized in that the carbon feed into the metal bath is effected until a decrease of the Cr and/or Ni oxide contents of the slag to values of between 0.8 wt.-% and 0.2 wt.-% and that, upon attainment of the pregiven Cr oxide content range of the slag, reductants having higher reduction potentials such as, e.g., Al, Ca, Si, Fe—Si or Ca—Si are added in order to lower the Cr and/or Ni oxide contents to below 0.15 wt.-%, preferably below 0.08 wt.-%.
Dependencies are inferred from the claim text.