Process for copper converting
The process for converting a copper sulphide matte to blister copper, is achieved by adding the copper sulphide matte and flux to a suitable agitated slag phase; and injecting, from a discharge tip at the lower end of a top-submerged lance, an oxidizing gas suitable for reacting with the matte to produce blister copper which forms or adds to a continuous blister copper phase below the slag phase. The lance tip is located within the slag phase at a depth enabling the injected gas to agitate the slag phase, and to react with copper sulphide matte dispersed therein, while precluding a substantial proportion of the gas from contacting the continuous blister copper phase.
1. A process for converting a copper sulfide matte to blister copper, wherein the process includes the steps of:
adding the copper sulfide matte and flux to an agitated iron based silicate slag phase; and
injecting, from a discharge tip at the lower end of a top-submerged lance, an oxidizing gas suitable for reacting with the matte to produce blister copper which forms or adds to a continuous blister copper phase below the iron based silicate slag phase;
wherein the depth of the iron based silicate slag phase and the level at which the discharge tip of the lance is located in the slag phase are such that the injected oxidizing gas agitates the slag phase and reacts with copper sulfide matte dispersed in the slag phase but so that a jet or stream of the injected oxidizing gas is unable to pass through a lower surface of the slag phase and the oxidizing gas within the jet or stream is precluded from contacting the continuous copper phase.
2. The process of claim 1 , wherein the slag phase has a depth of from about 500 mm up to about 2 m.
3. The process of claim 1 , wherein the slag phase has a depth of from about 700 mm to about 1.7 m.
4. The process of claim 1 , wherein the injection is at a mid-region of the height of the slag phase.
5. The process of claim 1 , wherein the injection is near the upper surface of the slag phase.
6. The process of claim 1 , wherein the injection is directed downwardly and laterally outwardly for agitating substantially the entire slag phase for substantially uniform dispersal of the copper sulfide matte throughout the slag phase.
7. The process of claim 1 , wherein the iron based silicate slag is a lime modified iron silicate slag.
8. The process of claim 7 , wherein the iron based silicate slag is a ferrous calcium silicate olivine slag.
9. The process of claim 7 , wherein the iron based silicate slag is an iron silicate fayalite slag.
10. The process of claim 7 , wherein the iron based silicate slag has a ratio of Fe to SiO2 of from 1.14 to 2.11, a weight to weight ratio of CaO to Fe of from 0.15 to 0.92, and a weight to weight ratio of CaO to SiO2 of from 0.22 to 1.11.
11. The process of claim 10 , wherein the weight to weight ratio of Fe to SiO2 is from 1.14 to 1.55.
12. The process of claim 1 , wherein a reductant is added to the slag phase for reducing the formation of magnetite and thereby suppressing foaming of the slag phase.
13. The process of claim 12 , wherein the reductant is lump coal.
14. A process for converting a copper sulfide matte to blister copper, wherein the process includes the steps of: adding the copper sulfide matte and flux to an agitated iron based silicate slag phase; and injecting, from a discharge tip at the lower end of a top-submerged lance, an oxidizing gas suitable for reacting with the matte to produce blister copper which forms or adds to a continuous blister copper phase below the iron based silicate slag phase; wherein the depth of the iron based silicate slag phase and the level at which the discharge tip of the lance is located in the slag phase are such that the injected oxidizing gas agitates the slag phase and reacts with copper sulfide matte dispersed in the slag phase but so that a jet or stream of the injected oxidizing gas is unable to pass through a lower surface of the slag phase and the oxidizing gas within the jet or stream is precluded from contacting the continuous copper phase, and tapping the blister copper produced periodically or at intervals.