Recovery of nickel chloride and sulfur from waste products
AssigneeTexaco Inc.
InventorsFan-Sheng Tao, Joseph B. Mitchell
Life of this patent
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Abstract
Waste containing sulfur and nickel sulfide is heated to volatilize sulfur and reacted with hydrogen chloride to form nickel chloride.
Claims10
The method of treating a charge composition containing elemental sulfur and an insoluble sulfide of a transition metal to recover therefrom the metal in a soluble form and elemental sulfur which comprises
- heating said composition under essentially anaerobic conditions, to a temperature above the volatilization point of sulfur thereby volatilizing sulfur and forming a residue which is substantially free of elemental sulfur;
- separating said volatilized sulfur from said residue;
- recovering said separated sulfur;
- acidifying said residue with an acid containing an anion which forms a water-soluble salt of said transition metal thereby forming solubilized metal salt and hydrogen sulfide;
- withdrawing said hydrogen sulfide;
- and
- recovering said solubilized metal salt.
The method of treating a charge composition containing elemental sulfur and nickel sulfide to recover therefrom elemental sulfur and nickel chloride which comprises
- heating said composition under essentially anaerobic conditions to 120.degree. C.-460.degree. C. thereby volatilizing sulfur and forming a residue which is substantially free of elemental sulfur;
- separating said volatilized sulfur from said residue;
- condensing said volatilized sulfur thereby forming condensed elemental sulfur;
- recovering said condensed elemental sulfur;
- treating said residue with hydrogen chloride thereby forming nickel chloride and hydrogen sulfide;
- withdrawing said hydrogen sulfide;
- and
- recovering said nickel chloride;
The method of treating a charge composition containing 94-100 parts of elemental sulfur and 0.01-2.5 parts of sulfide of a transition metal including nickel, to recover therefrom the metal in water-soluble form and elemental sulfur of higher purity than is present in said charge composition which comprises
- heating said composition under essentially anaerobic conditions to a temperature above the volatilization temperature of about 120.degree. C. of said sulfur and below about 400.degree. C. thereby volatilizing sulfur and forming a residue which contains less sulfur than is present in said charge composition and said residue containing a sulfide of a transition metal including nickel;
- separating said volatilized sulfur from said residue;
- condensing said volatilized sulfur thereby forming condensed elemental sulfur;
- recovering said condensed elemental sulfur;
- treating said residue with hydrogen chloride thereby forming nickel chloride and hydrogen sulfide;
- withdrawing said hydrogen sulfide;
- and
- recovering said nickel chloride.
Dependencies are inferred from the claim text.