Separation of calcium from metal compounds
AssigneeDrinkard Metalox, Inc.
InventorsWilliam F. Drinkard, Jr., Hans J. Woerner
Life of this patent
Estimating the term…
Abstract
A method of separating calcium from mixtures of metal oxides, sulfides, nitrates and carbonates. Particulate calcium containing mixtures are leached with nitric acid to form calcium nitrate and metal nitrates, which are heated to dryness and to form metal oxides, while not affecting the calcium nitrate. The resulting mixture is then leached with water to obtain a calcium nitrate containing leachate and a residue of low solubility metal oxides and insoluble metal oxides. If desired, the calcium nitrate can be decomposed to form a lime product.
Claims19
A method of separating calcium from other elements in a mixture of calcium-containing metal oxides, nitrates, sulfides, and carbonates, comprising:
- leaching the mixture with nitric acid to form a calcium-containing metal nitrate mixture;
- raising the temperature of the calcium containing metal nitrate mixture to a temperature sufficient to decompose all contained nitrates except calcium nitrate;
- and
- leaching the calcium containing metal nitrate mixture with water to obtain a calcium containing leachate and a residue of low solubility oxides and insoluble oxides.
A method of treating dolomitic limestone to separate calcium from magnesium, comprising:
- leaching the limestone with nitric acid to form a leachate containing water and a solid residue;
- separating and evaporating water from the leachate at a temperature from ambient to about 200.degree. C. to obtain a separated solid;
- heating the separated solid to a temperature of about 330.degree. to about 430.degree. C. to convert the magnesium to MgO;
- and
- washing the heated solid with water to obtain a calcium containing leachate product and insoluble MgO residue.
A method of separating calcium from other elements in a mixture of calcium-containing metal nitrates, comprising:
- heating the calcium-containing mixture to a temperature of from about 200.degree. C. to about 500.degree. C.;
- and
- leaching the calcium-containing mixture with water to obtain a calcium-containing leachate and a residue of low solubility oxides and insoluble oxides.
Dependencies are inferred from the claim text.