Method for preparing a sorbent
A method is described for preparing a sorbent including the steps of: (i) mixing together a particulate copper sulphide material, a particulate support material and one or more binders, (ii) shaping the mixture, and (iii) drying the shaped mixture to form a dried sorbent.
1. A method for preparing a sorbent comprising the steps of:
(i) mixing a particulate copper sulphide material, a particulate support material and one or more binders to form a mixture,
(ii) shaping the mixture by granulating the mixture in a granulator, and
(iii) drying the shaped mixture to form a dried sorbent, and
wherein the shaping comprises granulating the mixture in a granulator using a liquid and the amount of liquid is 0.1 to 0.5 mL/g of mixture.
2. The method according to claim 1 wherein the particulate copper sulphide material is manufactured by roasting copper or a copper compound with elemental sulphur, precipitating copper sulphide from solution, sulphiding a copper compound using hydrogen sulphide, or mixing powdered copper metal with elemental sulphur under conditions that cause the elemental copper and elemental sulphur to react to form one or more copper sulphides.
3. The method according to claim 1 wherein the copper sulphide comprises one or more copper sulphides that are copper (II) sulphide, CuS, or substoichiometric copper sulphides of formula Cu 2-x S where x is 0-1.
4. The method according to claim 1 wherein the particulate copper sulphide has an overall S:Cu atomic ratio of ≥0.8.
5. The method according to claim 4 wherein the particulate copper sulphide has an overall S:Cu atomic ratio of ≥0.9.
6. The method according to claim 4 wherein the particulate copper sulphide has an overall S:Cu atomic ratio of ≥0.95.
7. The method according to claim 1 wherein the particulate copper sulphide material is in the form of a powder with an average particle size, [D 50 ], in the range 5-100 μm.
8. The method according to claim 7 , wherein the particulate copper sulphide material is in the form of a powder with a D 50 in the range of 10-50 μm.
9. The method according to claim 1 wherein the copper content of the dried sorbent is in the range 10-75% by weight, expressed as CuS.
10. The method according to claim 9 wherein the copper content of the dried sorbent is in the range of 15-50% by weight.
11. The method according to claim 1 wherein the particulate support material is alumina, hydrated alumina, titania, zirconia, silica, aluminosilicate, or a mixture thereof.
12. The method according to claim 1 wherein the dried sorbent comprises 20-60% by weight of the particulate support material.
13. The method according to claim 1 wherein the binder is a clay binder, cement binder, or organic polymer binder.
14. The method according to claim 1 wherein the binder is a combination of a cement binder and a clay binder.
15. The method according to claim 14 wherein the relative weights of the cement binder and clay binder is in the range of 1:1 to 3:1.
16. The method according to claim 1 wherein the total amount of the binder in the dried sorbent is in the range of 5-30% by weight.
17. The method according to claim 1 wherein the total metal sulphide content of the sorbent, other than copper sulphide, is ≤5% wt.
18. The method according to claim 1 wherein the sorbent is dried at a temperature up to 120° C.
19. The method according to claim 1 wherein the total metal sulphide content of the sorbent, other than copper sulphide, is ≤1% wt.