Refractories and use thereof

Abstract

A refractory has the form of a dry, mineral batch of fire-resistant mineral materials combined in such a way that refractories which are long-term resistant to fayalite-containing slags, sulfidic melts (mattes), sulfates and non-ferrous metal melts and are used for refractory linings in industrial non-ferrous metal melting furnaces can be manufactured. The refractory at least contains: at least one coarse-grained olivine raw material as the main component; magnesia (MgO) meal; at least one fire-resistant reagent which, during the melting process, acts (in situ) in a reducing manner on non-ferrous metal oxide melts and/or non-ferrous metal iron oxide melts and converts same into non-ferrous metal melts.

Claims

1. Refractory product in the form of a dry, mineral batch of refractory mineral materials, for the production of refractory products for fire-side lining of industrial non-ferrous metal smelting furnaces, the dry, mineral batch comprising a basic batch consisting of the following basic batch components, which are mixed to come to 100 wt.-%: 15 to 74 wt.-% of at least one coarse-grained olivine raw material, with more than 70 wt.-% forsterite and less than 10 wt.-% of iron(III) oxide and having a grain size distribution by at least 95 wt.-%?1.0 mm, as the main component, 25 to 55 wt.-% magnesia meal (MgO meal) having less than 10 wt.-% of iron(III) oxide and less than 2.5 wt.-% of silicate secondary phases and having grain sizes of d.sub.95?1 mm, and 1 to 30 wt.-% of at least one refractory reagent that acts to reduce non-ferrous metal oxide melts and/or non-ferrous metal iron oxide melts during the smelting process (in situ) and to convert them to non-ferrous metal melts, wherein the reagent is fine-grained carbon having a fineness below 1000 ?m and wherein, in a mixture with the other components of the batch, the reagent is homogeneously distributed.

2. Product according to claim 1, wherein the fine-grained carbon is graphite and/or carbon black and/or anthracite and/or coke.

3. Product according to claim 1, comprising the following dry substance compositions: 30 to 65 wt.-% olivine raw material, 30 to 50 wt.-% magnesia meal, 5 to 20 wt.-% reagent.

4. Product according to claim 1, wherein in addition, the dry, mineral batch contains SiC.

5. Product according to claim 1, wherein in addition, the dry, mineral batch contains at least one fine-particle silicic acid that reacts with the MgO meal, when water is added to the dry, mineral batch, to form magnesium silicate hydrate phases.

6. Product according to claim 1, wherein in addition, the dry, mineral batch contains at least one known binder for refractory products, in dry, fine-particle form.

7. Product according to claim 6, wherein the binder is a binder that contains carbon.

8. Product in the form of a molded refractory brick, produced from a refractory batch according to claim 1, by mixing the dry, mineral batch with water and/or a liquid binder for refractory products, to form a moldable fresh mass, and pressing the fresh mass, wherein the reducing reagent is homogeneously distributed in the structure of the brick.

9. Product according to claim 8, having at least one binder phase that has hardened from the binder for refractory products and firmly connects the batch grains.

10. Product according to claim 8, wherein the brick is ceramically fired and has sintering bridges between batch grains.

11. Product according to claim 9, wherein the binder phase has a coke structure.

12. Product according to claim 8, having at least one binder phase, wherein the binder phase contains magnesium silicate hydrate.

13. Refractory product in the form of fire-side refractory masonry in the region of oxidizing smelting processes in an industrial non-ferrous metal smelting furnace built from refractory bricks according to claim 8.

14. Refractory product in the form of a monolithic fire-side refractory lining in the region of oxidizing smelting processes of an industrial non-ferrous metal smelting furnace produced by mixing a dry, mineral batch according to claim 1 with water and/or a liquid binder for refractory products, to form a fresh mass, lining the inner wall of the industrial non-ferrous metal smelting furnace with the fresh mass on the fire side, wherein the reducing reagent is homogeneously distributed in the structure of the lining.

15. Product according to claim 1, wherein the olivine raw material has more than 75 wt.-% forsterite.

16. Product according to claim 1, wherein the magnesia meal has >90 wt.-% or >95 wt.-% MgO.

17. Product according to claim 1, wherein the grain size of the olivine raw material lies by at least 95 wt.-% between 1 and 8 mm.

18. Product according to claim 4, wherein the dry, mineral batch contains the SiC in amounts up to 15 wt.-%.

19. Product according to claim 4, wherein the dry, mineral batch contains the SiC in amounts up to 10 wt.-%.

20. Product according to claim 5, wherein the dry, mineral batch contains the at least one fine-particle silicic acid in amounts up to 10 wt.-%.

21. Product according to claim 5, wherein the dry, mineral batch contains the at least one fine-particle silicic acid in amounts from 0.5 to 6 wt.-%.

22. Product according to claim 6, wherein the dry, mineral batch contains the at least one known binder in amounts up to 10 wt.-%.

23. Product according to claim 6, wherein the dry, mineral batch contains the at least one known binder in amounts up to 6 wt.-%.

24. Product according to claim 7, wherein the binder is tar and/or pitch and/or a synthetic resin binder.

25. Product according to claim 1, wherein the dry, mineral batch consists of the basic batch.

26. Product according to claim 8, wherein the brick is dried and/or tempered.

27. Product according to claim 13, wherein the industrial non-ferrous metal smelting furnace is a copper smelting furnace.

28. Product according to claim 14, wherein the lining is dried and/or tempered.

29. Product according to claim 14, wherein the industrial non-ferrous metal smelting furnace is a copper smelting furnace.

30. Refractory product in the form of fire-side refractory masonry in the region of inviscid non-ferrous metal oxides in an industrial non-ferrous metal smelting furnace, built from refractory bricks according to claim 8.

31. Refractory product in the form of fire-side refractory lining in the region of inviscid non-ferrous metal oxides in an industrial non-ferrous metal smelting furnace, produced by mixing a dry, mineral batch according to claim 1 with water and/or a liquid binder for refractory products to form a fresh mass, and lining the inner wall of the industrial non-ferrous metal smelting furnace with the fresh mass on the fire side, wherein the reducing reagent is homogeneously distributed in the structure of the lining.

32. A smelting method comprising: building a smelting furnace from refractory bricks according to claim 8, the refractory bricks forming fire-side refractory masonry of the smelting furnace, the refractory bricks facing a furnace zone within the smelting furnace; and smelting non-ferrous metal in the furnace zone of the smelting furnace in an oxidizing manner.

Description

(1) The invention will be explained in greater detail below, using examples, and will be clarified using a drawing as an example. The figures show:

(2) FIG. 1 a pressed, non-fired refractory brick according to the invention;

(3) FIG. 2 a crucible composed of brick according to the invention, after a test with sulfidic matte melt;

(4) FIG. 3 a crucible composed of brick according to the invention, after a test with copper oxide/iron oxide melt;

(5) FIG. 4 a crucible according to DE 10 2012 015 026 A1, after a test with sulfidic matte melt;

(6) FIG. 5 a crucible according to DE 10 2012 015 026 A1, after a test with copper oxide/iron oxide melt.

(7) FIG. 1 shows a pressed, non-fired refractory brick according to the invention, produced from the following formulation:

(8) TABLE-US-00001 Grain fraction mm Amount % Raw material Olivine 1-4 52 Melt magnesia 0-1 39 Graphite 5 Antioxidants 4 100 Binder Phenol-resol resin 3

(9) The brick according to the invention was dried at 200? C., to a residual moisture of 1.3 wt.-%.

(10) The matrix of the brick according to the invention demonstrates a support structure composed of relatively coarse olivine grains 1 (dark grains), finer grains 2 (white), as well as fine and micro-fine grains of MgO (not visible) and micro-fine black material 3 composed of graphite.

(11) The resistance of the invention with regard to fayalitic melt and copper melt is already known from DE 10 2012 015 026 A1.

(12) The superiority of the invention as compared with DE 10 2012 015 026 A1 and magnesia chromite bricks used until now consists in the resistance, as already described, with regard to copper oxide melt, copper iron oxide melt, and copper sulfide melt. This superiority is evident from the following crucible tests according to DIN 51069.

(13) A sulfidic matte melt, as well as a copper oxide-iron oxide melt from copper smelting was used, having the following mineral phase components:

(14) Phase components of sulfidic matte melt:

(15) bornite Cu.sub.5FeS.sub.4

(16) Cu.sub.2S

(17) wurtzite Zn.sub.0.6Fe.sub.0.4S

(18) cuprospinel CuFe.sub.2O.sub.4

(19) copper Cu

(20) Phase components of copper oxide-iron oxide melt:

(21) delafossite CuFeO.sub.2

(22) cuprospinel CuF.sub.2O.sub.4

(23) cuprite Cu.sub.2O

(24) copper Cu

(25) The chemical composition of the sulfidic matte melt was the following:

(26) TABLE-US-00002 SiO.sub.2 0.29% Al.sub.2O.sub.3 0.17% Fe.sub.2O.sub.3 14.50% Cr.sub.2O.sub.3 0.00% TiO.sub.2 0.00% CaO 0.05% MgO 0.09% SO.sub.3 27.40% NiO 0.00% CuO 56.20% ZnO 0.57% PbO 0.32%

(27) The chemical composition of the copper oxide-iron oxide melt was the following:

(28) TABLE-US-00003 SiO.sub.2 13.60% Al.sub.2O.sub.3 0.34% Fe.sub.2O.sub.3 33.60% Cr.sub.2O.sub.3 0.16% TiO.sub.2 0.00% CaO 0.09% MgO 0.29% SO.sub.3 0.07% NiO 0.28% CuO 48.20% ZnO 0.89% PbO 1.51%

(29) The slag, as a powder, was placed into a recess or a crucible of a non-fired brick according to the invention that had been prepared for a crucible test, heated to 1350? C., and held at this temperature for 6 h. After cooling, the crucibles were sawed open diagonally. The two molten slags did not penetrate into the brick. Corrosion of the brick according to the invention is also very slight, as can be seen from the contours of the crucible, which are still sharp. The sulfidic matte melt remained in the crucible completely, without any infiltration or dissolution processes being evident (FIG. 2). In the case of the test with copper oxide-iron oxide melt, it can furthermore be clearly seen that a major portion of the slag was reduced to metallic copper by means of the reagent contained (FIG. 3).

(30) In comparison, crucible tests were conducted using crucibles that were produced according to DE 10 2012 015 026 A1. The same slags were used for this purpose. After cooling and diagonal cutting of the crucibles, it was shown that the sulfidic melt partially penetrated into the brick according to DE 10 2012 015 026 A1 (FIG. 4). Furthermore, it was shown that the copper oxide-iron oxide melt completely penetrated into the brick according to DE 10 2012 015 026 A1 (FIG. 5). In contrast, the completely solidified copper melt 8 can still be found in crucible 4 from the FSM brick 10. Almost nothing penetrated into the brick.

(31) The brick according to the invention therefore comprises the following advantages as compared with the brick according to DE 10 2012 015 026 A1: in terms of application technology: The brick according to the invention is not penetrated by sulfidic matte melt and copper oxide-iron oxide melt, and therefore wears more slowly than a brick according to DE 10 2012 015 026 A1, because of the greater thermomechanical resistance.