Disclosure of Invention
The invention aims to provide a method for selectively leaching zinc in zinc ferrite-containing waste residue by mechanical activation and directional reduction. The method is based on the traditional zinc hydrometallurgy, and utilizes a ball mill to mechanically activate the zinc ferrite-containing waste residue, so that zinc in the zinc ferrite-containing waste residue is directionally reduced and selectively leached, and iron is made to be Fe3O4In the form of slag.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows: a leaching method of zinc in waste residue containing zinc ferrite at least comprises the following steps:
S1adding the waste residue containing zinc ferrite and a reducing agent into a ball milling tank according to a certain proportion, and performing ball milling to obtain a mechanically activated material;
S2under stirring, the mechanically activated material is added with H with a certain mass concentration2SO4Leaching in a solution;
S3after the leaching reaction is completed, carrying out suction filtration and drying.
A leaching method of zinc in waste residue containing zinc ferrite at least comprises the following steps:
S1adding the waste slag containing zinc ferrite into a ball milling tank, and performing ball milling to obtain a mechanically activated material;
S2under stirring, the mechanically activated material and the reducing agent are put into H with certain mass concentration2SO4Leaching in a solution;
S3after the leaching reaction is completed, carrying out suction filtration and drying.
Preferably, the reducing agent is selected from Na2SO3、H2C2O4、NaHSO3、(NH4)2SO3、NH4HSO3、ZnSO3And the like.
Preferably, the waste slag containing zinc ferrite comprises zinc calcine and electric furnace steelmaking dust.
Preferably, the material of the ball milling tank is any one of stainless steel, polytetrafluoroethylene, zirconia and silicon carbide.
Preferably, the ball-to-material ratio during ball milling is 1: 0.5-3, the ball milling frequency is 30 Hz, and the ball milling time is 1-8 h.
Preferably, the ratio of the mass of zinc ferrite in the waste residue containing zinc ferrite to the mol of the reducing agent is 5 g: 0.01 to 0.05 g/mol, preferably 5 g: 0.01 to 0.02 g/mol.
Preferably, H2SO4The mass concentration of the solution is not lower than 50 g/L, preferably not lower than 60 g/L; the leaching time is not less than 60 min.
Preferably, in H2SO4The mass of the zinc ferrite-containing waste residue and H when leached in solution2SO4The volume ratio of the solution (solid-to-liquid ratio) was 100 g/L.
Compared with the prior art, the invention has the following advantages:
(1) by mechanical activation in a reducing agent (Na)2SO3、H2C2O4、NaHSO3、(NH4)2SO3、NH4HSO3、ZnSO3Etc.) can lead ZnFe in the waste residue containing zinc ferrite to be reacted2O4The decomposition is more thorough, the leaching rate of zinc in a low-concentration sulfuric acid solution (70 g/L) reaches more than 95 percent, the leaching rate of iron is extremely low and is less than 0.2 percent, and the concentration of iron in the leaching solution is less than 20 ppm.
(2) The invention selectively realizes the leaching of zinc, reduces the generation of hazardous waste, reduces the time and cost of zinc smelting, and ensures that Zn is obtained2+The iron is leached to the maximum extent under the low acid concentration, and the iron is left in the slag in the form of ferroferric oxide, thereby solving the problem of iron vitriol slag in the zinc hydrometallurgy process from the source.
Detailed Description
The invention is further elucidated with reference to the figures and embodiments.
The invention can reduce ZnFe in waste residue containing zinc ferrite by mechanically activating the waste residue containing zinc ferrite2O4Stability of (5) and ZnFe2O4Effects of distortion and local destruction of the crystal lattice and formation of various defects, ZnFe2O4Reduction of stability leads to reduced Fe2+Is easier to migrate into the zinc ferrite to replace Zn2+Thereby realizing Zn2+Is leached of Fe2+Entering the zinc ferrite crystal to form magnetite. The magnetite is a spinel structure, is insoluble in dilute acid and alkali, is easy to separate from leaching slag, avoids the generation of iron-vanadium slag and realizes resource recovery.
The waste slag containing zinc ferrite mainly comprises zinc calcine, electric furnace steelmaking dust and the like. The electric furnace steelmaking dust is a product in the electric furnace steelmaking process, is generated by rapidly heating an electric arc furnace, and is generated under the conditions of high temperature (1600 ℃) and violent stirring, metal in smelting is evaporated at high temperature, is carried out of a furnace body by rising hot air flow, is oxidized, vulcanized or chlorinated in a dust collection system, is directly carried by the hot air flow to the dust collection system and is deposited in a dust collector to form the electric furnace steelmaking dust, and zinc in the electric furnace steelmaking dust mainly exists in the form of zinc oxide, and a few zinc ferrite exists in the form of zinc ferrite. The zinc calcine is a product obtained by roasting zinc concentrate, is a brown micro-granular solid, and mainly comprises zinc oxide, zinc ferrite and zinc silicate. The invention is not only suitable for separating iron and zinc in zinc ferrite in zinc calcine and dust collected by steel smelting plants, but also suitable for directional reduction and separation of other zinc ferrite-containing substances.
The zinc calcine used in the following examples is from the zinc industry llc company in shanxi han, the main components are zinc oxide, zinc ferrite and zinc silicate, and the total zinc content in the zinc calcine of the factory is 74.52% and the zinc ferrite content is about 10wt% by combining XRF, XRD and mineralogy analysis methods. The used ball grinding balls are zirconia big balls with the diameter of 10 mm and zirconia small balls with the diameter of 6 mm, the quantity of the big balls is basically consistent with that of the small balls, the diameter and the material of the ball grinding balls do not need to be particularly limited, and when the big balls and the small balls with different grain diameters are ground together, the mechanical activation effect is best.
Example 1
In this example, zinc in zinc calcine is leached selectively by a mechanical activation method, and the flow process is shown in fig. 2.
(1) Mixing zinc calcine with Na2SO3Adding 50 g of the raw materials into a zirconia ball-milling tank according to the proportion of 0.04 mol, mechanically activating the raw materials, adding ball-milling balls according to the ball-material ratio of 1: 2, setting the frequency to be 30 Hz, and carrying out ball-milling for 4 hours to obtain a mixture A; preparing a certain volume of H with the concentration of 50 g/L2SO4Taking the solution as leachate, weighing a certain amount of mixture A according to the solid-to-liquid ratio (the ratio of the mass of the zinc calcine to the volume of the leachate) of 100g/L, and slowly adding the weighed mixture A into H under stirring2SO4Reacting in the solution for 120 min to obtain a mixed system B;
(2) and (4) after suction filtration, drying, wherein the leaching amount of zinc is 28.36 g, the leaching rate of zinc can reach 76.11% through calculation, and iron is not leached into the solution.
Example 2
In this example, zinc in zinc calcine is leached selectively by a mechanical activation method, and the flow process is shown in fig. 2.
(1) Mixing zinc calcine with Na2SO3Adding 50 g of the mixture into a ball zirconia grinding tank in a proportion of 0.04 mol, mechanically activating the mixture, adding ball grinding balls according to a ball-to-material ratio of 1: 2, setting the frequency to be 30 Hz, and carrying out ball grinding for 2 hours to obtain a mixture A; preparing a certain volume of H with the concentration of 60 g/L2SO4Taking the solution as leachate, weighing a certain amount of mixture A according to the solid-to-liquid ratio (the ratio of the mass of the zinc calcine to the volume of the leachate) of 100g/L, and slowly adding the weighed mixture A into H under stirring2SO4Reacting in the solution for 120 min to obtain a mixed system B;
(2) after suction filtration and drying, the leaching amount of zinc is 31.24 g, the leaching rate of zinc can reach 83.83% through calculation, and iron is not leached into the solution.
Example 3
In this example, zinc in zinc calcine is leached selectively by a mechanical activation method, and the flow process is shown in fig. 2.
(1) Mixing zinc calcine with Na2SO3Adding 50 g of the raw materials into a zirconia ball-milling tank according to the proportion of 0.04 mol, mechanically activating the raw materials, adding ball-milling balls according to the ball-material ratio of 1: 2, setting the frequency to be 30 Hz, and carrying out ball-milling for 4 hours to obtain a mixture A; preparing a certain volume of H with the concentration of 60 g/L2SO4Weighing a certain amount of mixture A according to a solid-to-liquid ratio (the ratio of the mass of zinc calcine to the volume of leachate) of 100g/L, slowly adding the weighed mixture A into a sulfuric acid solution under stirring, and reacting for 120 min to obtain a mixed system B;
(2) and (3) after suction filtration, drying, wherein the leaching amount of zinc is 33.15 g, the leaching rate of zinc can reach 88.97 percent through calculation, and the concentration of iron in the solution is 14.23 ppm.
Example 4
In this example, zinc in zinc calcine is leached selectively by a mechanical activation method, and the flow process is shown in fig. 2.
(1) Mixing zinc calcine with Na2SO3Adding 50 g of the raw materials into a zirconia ball-milling tank according to the proportion of 0.05 mol, mechanically activating the raw materials, adding ball-milling balls according to the ball-material ratio of 1: 1, setting the frequency to be 30 Hz, and carrying out ball-milling for 3 hours to obtain a mixture A; preparing a certain volume of H with the concentration of 60 g/L2SO4Weighing a certain amount of mixture A according to a solid-to-liquid ratio (the ratio of the mass of zinc calcine to the volume of leachate) of 100g/L, slowly adding the weighed mixture A into a sulfuric acid solution under stirring, and reacting for 120 min to obtain a mixed system B;
(2) after suction filtration and drying, the leaching amount of zinc is 33.23 g, the leaching rate of zinc can reach 89.18% through calculation, and iron is not leached into the solution.
FIG. 1 is an X-ray diffraction chart of example 4, wherein FIG. 1(a) shows zinc calcine to which 0.05 mol of Na was added2SO3Zinc calcine after 3 h of mechanical activation and 60 g/L H2SO4Comparing XRD patterns of the leaching residue obtained after leaching, and FIG. 1(b) is a graph of FIG. 1(a)And (4) large graphs. As can be seen from fig. 1, after mechanical activation, the characteristic peak of zinc oxide in the zinc calcine is obviously enhanced, and the characteristic peak of zinc ferrite (actually, the zinc ferrite and ferroferric oxide are superimposed) is enhanced; 60 g/L H was used2SO4After leaching, the characteristic peak of zinc oxide in leaching residue is obviously reduced, and the characteristic peak of partial zinc oxide disappears; in addition, the characteristic peak of the ferroferric oxide is enhanced compared with the slag after mechanical activation, which shows that the mechanical activation indeed leads the zinc ferrite to be directionally reduced into zinc oxide and ferroferric oxide (because the ferroferric oxide and the zinc ferrite have a spinel structure, the positions of the characteristic peaks are almost overlapped, and only the characteristic peak of the ferroferric oxide is shifted to the right compared with the zinc ferrite).
Example 5
In this example, zinc in zinc calcine is leached selectively by a mechanical activation method, and the flow process is shown in fig. 2.
(1) Adding zinc calcine and oxalic acid into a zirconia ball milling tank according to the proportion of 50 g: 0.01 mol for mechanical activation, adding ball milling balls according to the ball-to-material ratio of 1: 2, setting the frequency to be 30 Hz, and carrying out ball milling for 5 hours to obtain a mixture A; preparing a certain volume of H with the concentration of 70 g/L2SO4Weighing a certain amount of mixture A according to a solid-to-liquid ratio (the ratio of the mass of zinc calcine to the volume of leachate) of 100g/L, slowly adding the weighed mixture A into a sulfuric acid solution under stirring, and reacting for 120 min to obtain a mixed system B;
(2) and (3) after suction filtration, drying, wherein the leaching amount of zinc is 36.70 g, the leaching rate of zinc can reach 98.51% through calculation, and the concentration of iron in the solution is 23.25 ppm.
Example 6
In this example, zinc in zinc calcine is leached selectively by a mechanical activation method, and the flow process is shown in fig. 2.
(1) Adding zinc calcine and oxalic acid into a zirconia ball milling tank according to the proportion of 50 g: 0.02 mol for mechanical activation, adding ball milling balls according to the ball-to-material ratio of 1: 2, setting the frequency to be 30 Hz, and carrying out ball milling for 3 hours to obtain a mixture A; preparing a certain volume of H with the concentration of 70 g/L2SO4Weighing a solution according to the solid-to-liquid ratio of 100g/L (the ratio of the mass of the zinc calcine to the volume of the leaching solution)Slowly adding the weighed mixture A into a sulfuric acid solution under stirring to obtain a quantitative mixture A, and reacting for 120 min to obtain a mixed system B;
(2) after suction filtration and drying, the leaching amount of zinc is 35.64 g, the leaching rate of zinc is calculated to be 95.65%, and the concentration of iron in the solution is 4 ppm.
Example 7
In this example, zinc in zinc calcine is leached selectively by a mechanical activation method, and the flow process is shown in fig. 2.
(1) Adding zinc calcine and oxalic acid into a zirconia ball milling tank according to the proportion of 50 g: 0.02 mol for mechanical activation, adding ball milling balls according to the ball-to-material ratio of 1: 2, setting the frequency to be 30 Hz, and carrying out ball milling for 3 hours to obtain a mixture A; preparing a certain volume of H with the concentration of 70 g/L2SO4Weighing a certain amount of mixture A according to a solid-to-liquid ratio (the ratio of the mass of zinc calcine to the volume of leachate) of 100g/L, slowly adding the weighed mixture A into a sulfuric acid solution under stirring, and reacting for 60 min to obtain a mixed system B;
(2) after suction filtration and drying, the leaching amount of zinc is 33.16 g, the leaching rate of zinc is 89.00 percent by calculation, and the concentration of iron in the solution is 15 ppm.
Example 8
In this example, zinc in zinc calcine is leached selectively by a mechanical activation method, and the flow process is shown in fig. 2.
(1) Mixing zinc calcine with NaHSO3Adding 50 g of the raw materials into a zirconia ball-milling tank according to the proportion of 0.04 mol, mechanically activating the raw materials, adding ball-milling balls according to the ball-material ratio of 1: 2, setting the frequency to be 30 Hz, and carrying out ball-milling for 3 hours to obtain a mixture A; preparing a certain volume of H with the concentration of 70 g/L2SO4Weighing a certain amount of mixture A according to a solid-to-liquid ratio (the ratio of the mass of zinc calcine to the volume of leachate) of 100g/L, slowly adding the weighed mixture A into a sulfuric acid solution under stirring, and reacting for 120 min to obtain a mixed system B;
(2) after suction filtration and drying, the leaching amount of zinc is 35.60 g, the leaching rate of zinc is calculated to be 95.54%, and the concentration of iron in the solution is 4.25 ppm.
Example 9
In this example, zinc in zinc calcine is leached selectively by a mechanical activation method, and the flow process is shown in fig. 2.
(1) Calcining zinc and NH4HSO3Adding 50 g of the raw materials into a zirconia ball-milling tank according to the proportion of 0.02 mol, mechanically activating the raw materials, adding ball-milling balls according to the ball-material ratio of 1: 2, setting the frequency to be 30 Hz, and carrying out ball-milling for 5 hours to obtain a mixture A; preparing a certain volume of H with the concentration of 70 g/L2SO4Weighing a certain amount of mixture A according to a solid-to-liquid ratio (the ratio of the mass of zinc calcine to the volume of leachate) of 100g/L, slowly adding the weighed mixture A into a sulfuric acid solution under stirring, and reacting for 120 min to obtain a mixed system B;
(2) after suction filtration and drying, the leaching amount of zinc is 36.10 g, the leaching rate of zinc is calculated to be 96.89%, and the concentration of iron in the solution is 2.46 ppm.
Example 10
(1) Adding 50 g of zinc calcine into a zirconia ball milling tank for mechanical activation, adding ball milling balls according to the ball-to-material ratio of 1: 2, setting the frequency to be 30 Hz, and carrying out ball milling for 3 hours; preparing a certain volume of H with the concentration of 70 g/L2SO4Solution of zinc calcine and (NH)4)2SO3The zinc calcine ball milling slag and (NH) are weighed according to the proportion of 50 g to 0.01 mol4)2SO3Mixing the weighed zinc calcine ball-milling slag and (NH) under stirring4)2SO3Slowly adding H according to the solid-to-liquid ratio of 100g/L (the ratio of the mass of the zinc calcine to the volume of the leaching solution)2SO4Reacting in the solution for 120 min;
(2) after suction filtration and drying, the leaching amount of zinc is 32.65 g, the leaching rate of zinc is calculated to be 87.63 percent, and the concentration of iron in the solution is 5.46 ppm.
Example 11
In this example, zinc in zinc calcine is leached selectively by a mechanical activation method, and the flow process is shown in fig. 2.
(1) Mixing zinc calcine and ZnSO3Adding 50 g of the mixture into a zirconia ball milling tank in a proportion of 0.01 mol, mechanically activating the mixture, and adding balls according to a ball-to-material ratio of 1: 2Grinding balls, setting the frequency to be 30 Hz, and performing ball milling for 3 hours to obtain a mixture A; preparing a certain volume of H with the concentration of 70 g/L2SO4Weighing a certain amount of mixture A according to a solid-to-liquid ratio (the ratio of the mass of zinc calcine to the volume of leachate) of 100g/L, slowly adding the weighed mixture A into a sulfuric acid solution under stirring, and reacting for 120 min to obtain a mixed system B;
(2) after suction filtration and drying, the leaching amount of zinc is 35.68 g, the calculated leaching rate of zinc is 95.76%, and the concentration of iron in the solution is 6.85 ppm.
Example 12
(1) Adding electric furnace steelmaking dust (the content of zinc ferrite is about 20 wt%) and oxalic acid into a zirconia ball-milling tank according to the proportion of 50 g: 0.01 mol for mechanical activation, adding ball-milling balls according to the ball-material ratio of 1: 2, setting the frequency to be 30 Hz, and carrying out ball-milling for 2 hours to obtain a mixture A; preparing a certain volume of H with the concentration of 70 g/L2SO4Weighing a certain amount of mixture A according to a solid-to-liquid ratio (the ratio of the mass of zinc calcine to the volume of leachate) of 100g/L, slowly adding the weighed mixture A into a sulfuric acid solution under stirring, and reacting for 120 min to obtain a mixed system B;
(2) after suction filtration and drying, the leaching amount of zinc is 34.70 g, the leaching rate of zinc is calculated to be 93.12%, and the concentration of iron in the solution is 7.59 ppm.
As can be seen from the above examples, the present invention utilizes the mechanical activation method to make zinc ferrite lattice generate distortion and defect, and the zinc ferrite is directionally reduced into ZnO which is easy to dissolve in acid and Fe which is not easy to dissolve in acid3O4The zinc is made to enter the solution and the iron is left in the slag, the zinc ferrite-containing waste slag is leached by sulfuric acid after mechanical activation, the leaching rate of the zinc reaches more than 95 percent, and the concentration of the iron in the solution is lower than 20 ppm. The method not only reduces the dosage of acid and saves cost, but also separates zinc and iron and shortens the process flow of zinc extraction while ensuring the zinc leaching rate.
Comparative example 1
(1) 50 g of zinc calcine is weighed and prepared into a certain volume of H with the concentration of 70 g/L2SO4Solution with solid-to-liquid ratio of 100g/L (mass of zinc calcine)The volume ratio of the zinc calcine to the leaching solution), slowly adding the weighed zinc calcine into a sulfuric acid solution under stirring, and reacting for 120 min to obtain a mixed system B;
(2) after suction filtration and drying, the leaching amount of zinc is 19.60 g, the leaching rate of zinc is calculated to be 52.60%, and the concentration of iron in the solution is 70.60 ppm.
Comparative example 2
(1) 50 g of zinc calcine and 0.01 mol of oxalic acid are weighed to prepare a certain volume of H with the concentration of 70 g/L2SO4Adding the weighed zinc calcine and oxalic acid into the solution slowly under stirring according to the solid-to-liquid ratio of 100g/L (the ratio of the mass of the zinc calcine to the volume of the leaching solution)2SO4Reacting in the solution for 120 min;
(2) after suction filtration and drying, the leaching amount of zinc is 21.84 g, the leaching rate of zinc is calculated to be 58.62 percent, and the concentration of iron in the solution is 61.73 ppm.