Process for refining lead bullion
AssigneeStannum Group LLC
InventorsMiguel Pizzuto, Robert Seebeck, Jerry D. Schulz
Life of this patent
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Abstract
A unique pyrometallurgical lead refining process includes adding a Lewis acid component and an Arrhenius base compound to a molten lead bullion. The Lewis acid component and Arrhenius base compound are added in stoichiometric amounts that preferentially remove lighter amphoteric elements from the molten lead bullion, and promote reactions with amphoteric p-block elements in the lead bullion to form over the lead a slag of Lewis bases, thereby forming a slag layer incorporating the metal salts of the amphoteric p-block elements.
Claims20
A process for refining lead bullion to separate lead from impurities including amphoteric p-block elements, copper, sulfur, selenium, and tellurium, the process including:
- maintaining lead bullion at a temperature just above its melting point;
- removing copper from the bullion,
- heating the lead bullion to a processing temperature in the range of 750° F. to 850° F.;
- maintaining the lead bullion at the processing temperature,
- adding a Lewis acid component and an Arrhenius base compound to the molten lead bullion, the Lewis acid being added in stoichiometric amounts to the amounts of lighter amphoteric elements to be preferentially removed from the molten lead bullion to promote reactions with amphoteric p-block elements in the lead bullion to form over the lead bullion a slag of Lewis bases, thereby forming a slag layer incorporating metal salts of the amphoteric p-block elements;
- and
- periodically removing at least a majority of the slag layer from the top of the lead bullion.
A lead refining method comprising:
- heating a lead bullion having impurities including amphoteric elements p-block elements to a processing temperature between about 750° F. and about 850° F.;
- and
- adding a Lewis acid component and an Arrhenius base compound to the molten lead bullion, the Lewis acid being added in stoichiometric amounts to the amounts of lighter amphoteric elements to be preferentially removed from the molten lead bullion to promote reactions with amphoteric p-block elements thereby forming a slag layer incorporating the metal salts of the amphoteric p-block elements on the lead bullion.
A process for refining lead bullion, including:
- maintaining lead bullion at a temperature just above its melting point;
- removing copper from the bullion;
- adding metallic sodium or calcium to the bullion;
- removing the slag created by the addition of the metallic sodium or calcium;
- bringing the lead bullion to a processing temperature in the range of 750° F. to 850° F.;
- maintaining the lead bullion at the processing temperature;
- adding a Lewis acid component and an Arrhenius base compound to the molten lead bullion, the Lewis acid being added in stoichiometric amounts to the amounts of lighter amphoteric elements to be preferentially removed from the molten lead bullion to promote reactions with amphoteric p-block elements thereby forming a slag layer incorporating the metal salts of the amphoteric p-block elements on the lead bullion;
- and
- periodically removing at least a majority of the slag layer from the top of the lead bullion.
Dependencies are inferred from the claim text.