Process for the acid digestion of metal-containing compounds
Aqueous leachant compositions and processes for using the same comprising: (a) providing a metal-containing compound; and (b) subjecting the metal-containing compound to an acid digestion comprising contacting the metal-containing compound with an aqueous leachant; wherein the aqueous leachant comprises a mixture selected from the group consisting of: (i) sulfuric acid and one or more alkanesulfonic acids having alkane moieties selected from the group consisting of propyl, ethyl and methyl groups, at a weight ratio of alkanesulfonic acid to sulfuric acid of 1:1000 to 1:1; (ii) sulfuric acid and one or more salts of alkanesulfonic acids having alkane moieties selected from the group consisting of propyl, ethyl and methyl groups, at a weight ratio of salt of alkanesulfonic acid to sulfuric acid of 1:9 to 1:99.
1. A process comprising:
providing a metal-containing compound; and
subjecting the metal-containing compound to an acid digestion comprising contacting the metal-containing compound with an aqueous leachant;
wherein the aqueous leachant comprises a mixture of:
sulfuric acid and one or more alkanesulfonic acids having alkane moieties selected from the group consisting of propyl, ethyl and methyl groups, at a weight ratio of alkanesulfonic acid to sulfuric acid of 1:39 to 1:1.
2. The process according to claim 1 , wherein the concentration of the sulfuric acid is 0.1 to 50% by weight.
3. The process according to claim 1 , wherein the concentration of the one or more alkanesulfonic acids is 0.001 to 50% by weight.
4. The process according to claim 1 , wherein the alkanesulfonic acid comprises methanesulfonic acid.
5. The process according to claim 1 , wherein the leachant further comprises one or more surfactants selected from the group consisting of nonionics, anionics, cationics, amphoterics and mixtures thereof.
6. The process according to claim 5 , wherein the surfactant is present at a concentration of 0.01 to 0.3% by weight, such that a reduction in the contact angle on glass by at least 10° after 1 second in 2% strength aqueous H 2 SO 4 solution at 23° C. is provided.
7. The process according to claim 5 , wherein the surfactant is present at a concentration of 0.05 to 0.25% by weight, providing for a reduction in the contact angle on glass by at least 20° after 0.5 second in 2% strength aqueous H 2 SO 4 solution at 23° C.
8. A copper-winning process comprising the process according to claim 7 .
9. The process according to claim 1 , wherein the metal-containing compound comprises a metal component selected from the group consisting of copper, titanium, CaF 2 , zinc, lead, molybdenum, antimony, bismuth, mercury, cobalt, nickel, aluminium, lanthanum, lanthanides, uranium or a combination thereof.
10. The process according to claim 9 , wherein the metal-containing compound comprises a metal component selected from the group consisting of copper, zinc, lanthanum, lanthanides, uranium and combinations thereof.
11. The process according to claim 9 , wherein the metal-containing compound comprises a metal component selected from the group consisting of copper, titanium, CaF 2 and combinations thereof.
12. The process according to claim 1 , wherein the metal-containing compound comprises a metal component selected from the group consisting of copper, titanium, CaF 2 , and combinations thereof.
13. A copper-winning process comprising the process according to claim 1 .
14. The process of claim 1 , wherein the metal-containing compound comprises copper.
15. The process of claim 1 , wherein the metal-containing compound comprises a metal component selected from the group consisting of titanium, CaF 2 , zinc, lead, molybdenum, antimony, bismuth, mercury, cobalt, nickel, aluminium, lanthanum, lanthanides, uranium or a combination thereof.
16. The process of claim 1 , wherein the metal-containing compound comprises TiO 2 or CaF 2 .