TW201109445A - Method for recycling metal from collection ash or rough refined zinc oxide - Google Patents

Abstract

The invention is a method for recycling metal from collection ash and rough refined zinc oxide comprising steps of providing collection ash and rough refined zinc oxide containing at least ferrite and zinc; melting the collection ash and rough refined zinc oxide in a concentrated sulfuric acid to form a collection ash or rough refined zinc oxide acidic solution, wherein pH is less than 2; then adding another set of collection ash and its rough refined zinc oxide into the filter solution to allow pH go up to 2 to 3.5 so that parts of the collection ash and its rough refined zinc oxide are dissolved; filtering the solution to obtain residue and ferrite-containing zinc sulfate filtered solution; adding zinc-containing compound into the ferrite-containing zinc sulfate filtered solution so that its pH goes up to 3.5 to 7 when the temperature is at 40 to 120DEG C, thereby precipitating ferrite within the filtered solution upon ferrite hydroxide. The invention is that different metal compounds are separated at different pH environments by regulating pH values. The cost can be reduced while using the collection ash and its rough refined zinc oxide to adjust pH value.

Description

201109445 VI. Description of the Invention: [Technical Field of the Invention] The present invention is a method for recovering metal from dust collecting ash or its crude zinc oxide, in particular, a simple and low-cost process from dust collecting ash or its coarse A method of recovering zinc and iron from zinc oxide. [Prior Art]

The dust collection ash is a kind of soot produced by electric arc furnace steelmaking. The main elements in the dust collection ash are oxides containing iron (3 〗 〖%), oxygen (3 〇%), zinc (7)%), manganese (3%), lead (1.5%), and the rest are potassium, sodium, aluminum. , calcium, town, chlorine, antimony, sulfur and other elements, even containing heavy metals such as cadmium, lead, chromium, nickel. Since there are hundreds of thousands of tons of dust-collecting ash containing toxic heavy metals such as cadmium, lead, chromium, zinc and brocade every year in China, and it is bulky and loose, it is difficult to handle. " , 1 问题 问题 ' 主要 主要 主要 主要 主要 主要 主要 主要 主要 主要 主要 主要 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩 掩Containing ^ to discard it at will and secretly 1 These heavy metals will be polluted by groundwater, rivers and oceans. He reduces the method: Μ reduces zinc oxide to zinc vapor, so that zinc and two knives are separated from bismuth zinc and then oxidized to produce oxidation = the zinc oxide recovered contains large:: zinc oxide can only be used as a scouring zinc plant. The faulty and oxidized record PJ5隹; and ., ·, as a commercial grade zinc sold 'so economic value is not high. Fire law and metallurgy chain: the system will put the dust collection ash in the high temperature rotary shovel to reduce the 201109445 gas-like burning 'reduction error and record the g /μ from the ^^ fresh oxide, so that the lead and zinc vapors are evaporated and separated, but will The ship's zinc metal is recovered; the bran is too much, the soil is β ..., and the product to be paid by this side is the oxide containing lead and zinc ~, and this is used as a wrong zinc ore chain, so the utilization value is not high. In wet smelting, the dust ash is first dissolved in sulfuric acid to form zinc sulphide, and the zinc sulphate is purified and then zinc bond is obtained by electrolysis. In addition to zinc oxide and gasified iron, the dust ash contains a large amount of ferrite magnets (MnxZni_xFe2〇4) 'and the properties of ferrite magnets are insoluble in dilute sulfuric acid' but soluble in #vL In order to avoid iron being dissolved, in order to avoid the dissolution of iron, the use of wet ash to avoid the use of concentrated sulfuric acid, but the disadvantage is that zinc dissolution is not complete (dissolution rate σ ancient 7 "0 / mountain, Half of the solution, about 75%), the remaining zinc and all the lead are still in the residue left, and g &1 ν and seeing some of the residue must still be treated in a buried manner. Therefore, there will still be problems with environmental pollution. Even if the fire method is used to smash Λατ altar wet/smelt, it is impossible to recover the largest part of the collected dust ash and discard it, and it is not effective to recover zinc. Therefore, the current collection method of dust collection ash There is still a need for improvement to save costs, which is the current active research goal of the relevant industry. SUMMARY OF THE INVENTION The present inventors have had a method in which the existing methods cannot effectively recover words and iron, and therefore, after long-term research and continuous experimentation, the invention has finally invented this dust collection ash or its smelting. A method of recovering metals from zinc oxide. The object of the present invention is to provide a method for recovering zinc and iron from a dust ash or a crude zinc oxide thereof which is simple and low-cost. = the above object 'The method for recovering metal from the dust collecting ash or its crude oxidation word, the method comprising: j providing dust collecting ash containing at least iron and zinc or its crude oxidation word; 201109445 dust /== : Its crude zinc oxide is dissolved in _ to form a dust collecting fire, eight crude oxidized acidity! ♦ ♦ liquid, the pH is less than 2; another dust ash or its crude zinc oxide is added to the zinc oxide acidic solution, so that the pH rises to 2~35 = dust fire l is refined according to the alkaline solution The residual house is removed to form an acidic filtrate; the zinc-containing compound is added to the acid X-dead filtrate, and the temperature is raised to 3 5~7 at a temperature of 4 〇·12 4 4 ' with argon iron as argon Type precipitation of iron oxide. Wherein the zinc-containing compound includes, but is not limited to, metal (4), zinc oxide (10), zinc carbonate (ZnC〇3), and hydroxide [[(OH)". Wherein, after the zinc sulphate is obtained, the zinc sulphate is electrolyzed to obtain the metal xiao; or the zinc sulphate and the sodium hydride are used to sink the cerium to obtain zinc oxide. The electrolysis condition is 2G~4Qg per liter of material, and the current density is square 丨G (the best electrolysis efficiency is 60~95% under the Bucher ampere. The L after obtaining the ferric oxide is 'high temperature dry ' The iron hydroxide is used to obtain iron oxide. Preferably, after the dust collecting ash or its crude oxidation is provided, the method includes: at least one water washing step to remove the dust collecting ash or its crude zinc oxide. Gas and sodium.

Preferably, the pH of the dust collecting ash or its crude zinc oxide acidic solution is less than one. Preferably, another dust ash or its crude zinc oxide is added to the iron-containing liquid to increase the pH to between 3.5 and 6.

The invention can dissolve concentrated dust ash or its crude zinc oxide by using concentrated sulfuric acid to completely dissolve the iron-zinc compound, and then adjust the pH so that different metal salts are precipitated at different pH 201109445, so when zinc sulfate is produced Iron does not precipitate out 'but the iron is precipitated with iron hydroxide after the pH is raised, and S · The present invention uses the dust collection ash to adjust the pH' so that the dust ash or its coarse zinc oxide can be fully utilized. 'And reducing the cost, the present invention can effectively remove the words and iron from the dust collecting ash or its crude zinc oxide in the case of cost reduction, and avoid waste of valuable metals in the dust collecting ash or its crude zinc oxide. [Embodiment] Referring to Figure - Figure, the present invention is a method for recovering metal from dust ash or its crude oxidation, which includes: providing dust collection containing iron, zinc, sodium, gas, and the like Ash or its crude zinc oxide; washing the dust ash to remove sodium and chlorine; the word dust or its crude zinc oxide is dissolved in concentrated sulfuric acid to form dust ash or its crude zinc oxide acidic solution , #pH is less than 2, preferably pH is less than 1; 另Add another dust collection ash or its crude zinc oxide to the dust ash or its crude zinc oxide acidic solution to raise the pH to 2~3.5 The acidic solution is filtered to remove the residue to form an acidic filtrate; the zinc-containing compound is added to the acidic filtrate, and the pH is raised to between 3.5 and 7 at a temperature of 4 〇 12 〇 ec. It is raised to between 3 5 and 6 'to make iron precipitate in the form of iron hydroxide. When the pH is less than 3 5, no iron hydroxide precipitates. If the pH continues to rise, it must be added = Zinc compounds, so in the case of cost considerations, the pH must be less than 6,4 zinc-containing compounds included but Restricted to zinc metal, oxidized (ZnO) zincate (ZnC〇3), zinc hydroxide, etc., the preferred compound is zinc oxide; 201109445 Filter the acidic filtrate containing iron hydroxide to obtain hydroxide respectively Iron and zinc sulfate filtrate; zinc sulfate may then be electrolyzed to obtain metallic zinc, or zinc sulfate and hydroxide (iv) may be m to obtain zinc oxide; i and the iron hydroxide is dried at a high temperature to obtain iron oxide. Example

The following examples are not intended to limit the invention, but are merely used to exemplify the invention 'to enable a person of ordinary skill in the art to practice the invention' and the actual scope of the invention is still to be For the sake of the present invention, any modification of the quantity, temperature, etc., which is carried out under the principles of the present invention, is still within the scope of the present invention. Example 1 30 kg of dust collection ash was provided, and the ICP-(10) analysis was carried out by an inductively coupled plasma emission photometer (10), and it was found that iron, zinc, sodium, ^ dance, gas and the like were contained (see Figure 2 and Table υ, and the main crystalline phase of the three phases of ferroferric oxide and zinc oxide. Wash the dust ash three times to remove 97% of the chlorine in the coffee and coffee (see Table 2), set Dust ash is dissolved in concentrated sulfuric acid liters, dust ash acidic solution, retanning & 隹 〃 ΡΗ ΡΗ is less than 1, the other - dust ash added: : dust ash acidic solution, so that the positive value rises to 25, In order to collect dust ash acid, the concentration of zinc iron in the liquid rises, after the sputum, the zinc sulphate solution and the braid are added to add 5 kg of the zinc-containing compound to the value of 201109445 in the iron-containing liquid to rise to 3.5, Prepare the island for iron oxide precipitation, and then pass through the zinc-containing zinc sulfate filtrate to obtain ^~~3 aerobic yttrium oxide (tetra) iron and zinc sulphate sputum, liquid, and finally zinc sulphate filtrate into sputum electrolysis, pot啻a Take Junke, the current density is 2〇(2) per square meter, and 20% of the T-chuan 〇 培 , , , , , , , , , , , , , , 93 93 93 93 93 93 93 93 Fresh efficiency iron J%L Zinchuang wrong Li Chong copper one class 'nickel _) Magnesium chromium cadmium jPPtn) _) Ming Na _ (PPm) Silver (PPm) ji' (ppm) Chlorine (ΡΡΙΒ) 29.17 25.56 1.82 1.63 2197.6 68.4 12781 1791.1 157.3 17979 4462 22386 65.5 851.8 12395 Table 1_Contents of elements contained in the initial dust ash

The content of the elements contained in the flat-class I washing long-term T_soluble salt removal rate element for the first time, the second time, the third time, the box is slightly east magnesium Mg) 8% 0%, like {夕", half 9% calcium ( Ca) 21% 3% 2% 0^0/ nano (Na) 62% 8% 3% ^ Ό /〇η Ά gas (Cl) 85% 9% 3% 97% Example 2 & for 100 kg of coarse The zinc oxide is analyzed by an inductive light-weight plasma emission spectrometer (ICP-OES), and it is found that iron, zinc, sodium, magnesium, calcium, gas and the like are contained therein. The crude oxidation word is dissolved in 50%. 1 liter of concentrated sulfuric acid to form a crude zinc oxide acidic solution, the pH of which is less than 1, another crude zinc oxide is added to the crude zinc oxide acidic solution, so that the pH rises to 2.5, so that the thick 201109445 After the liter, the solution is filtered to obtain a zinc-iron concentration solution and a residue solid in the zinc sulfate iron solution.

Adding up to $80 kg of zinc-containing compound to the iron-containing mash, raising the pH to 3.5 to precipitate iron hydroxide, and filtering the filtrate containing zinc hydroxide containing zinc hydroxide to obtain iron hydroxide and zinc sulfate Filtration &, finally, the sulfur-zinc filter liquid is acid-tested to form high-purity zinc oxide, and the acidity and neutralization conditions are 80-120t, neutralized with sodium hydroxide, and the pH is 7_1〇. The purity is 9〇·〇-99·8°/. Zinc oxide. The method of the invention can effectively recover zinc and iron, and the iron can be further used for manufacturing iron cores for motors and transformers, etc., so that the problem that the dust collecting ash processing method cannot effectively recover iron can be solved, and the iron can be effectively provided. Industrial use. BRIEF DESCRIPTION OF THE DRAWINGS The first figure is a schematic flow chart of the present invention. The first figure is an ICP-OES spectrum of the initial dust collection ash in the first embodiment of the present invention. [Main component symbol description]

Claims (1)

201109445 VII. Patent application scope: 1. A method for recovering metal from dust collecting ash or its crude zinc oxide, comprising: providing dust collecting ash containing at least iron and zinc or its crude zinc oxide; Ash or its crude zinc oxide is dissolved in concentrated sulfuric acid to form a dust collecting ash or its crude zinc oxide acidic solution having a pH of less than 2; another dust dust or its crude zinc oxide is added to the dust collecting ash Or the crude zinc oxide acidic solution, the pH is raised to between 2 and 3.5; the acidic solution is filtered to remove the residue to form an acidic liquid; and the zinc-containing compound is added to the acidic filtrate at a temperature of 4 〇 At 12 〇, 'the pH is raised to between 3.5 and 7, so that the iron precipitates in the form of iron oxide. 2. The method for recovering metal from dust ash or its crude zinc oxide as described in claim 1, wherein the zinc-containing compound is selected from the group consisting of zinc metal (Zn), Zinc oxide (Zn〇), zinc carbonate (ZnC03), and zinc hydroxide [Zn(〇H)2]. 3. The method for recovering metal from dust ash or its crude oxidation sulphur as described in the scope of the patent application, in which the dust ash or its crude zinc oxide is provided, is also included in the at least one water washing dust ash. step. 4. A method for recovering metal from dust ash or its crude zinc oxide as described in claim 2, wherein the provision of dust ash or its crude zinc oxide does not include at least one water washing dust ash. step. 5. The method for recovering metal from dust ash or its crude zinc oxide according to any one of claims 1 to 4, wherein ρίί of the dust ash or its crude zinc oxide acidic solution is less than 2. 201109445 6. The method for collecting metal from dust ash or its crude zinc oxide according to any one of claims 4 to 4, wherein the dust ash or its crude zinc oxide is added In the dust collecting ash or its crude zinc oxide acidic solution, the pH is raised to between 3.5 and 6. 7. In the method of recovering metal from dust ash or its crude zinc oxide as described in item 5 of the patent scope, the dust ash or its crude zinc oxide is added to the dust ash or its coarse In the acidic solution of zinc oxide, the pH is raised to between 3.5 and 6. 8. The method for collecting metal from dust ash or its crude zinc oxide according to any one of claims 4 to 4, wherein the sputum further comprises filtering the iron hydroxide-containing after the iron hydroxide sink. The acidic filtrate was used to obtain a filtrate of iron hydroxide and zinc sulfate, respectively. 9. The method for recovering metal from dust collecting ash or its crude zinc oxide according to claim 5, wherein after the iron hydroxide precipitation, filtering the acidic filtrate containing iron hydroxide to obtain hydrogen respectively Iron oxide and zinc sulfate filtrate. 10. The method for recovering metal from dust ash or its crude zinc oxide as described in claim 6, wherein the ferric hydroxide-containing acidic filtrate is filtered after the iron hydroxide precipitation to obtain hydrogen respectively. Iron oxide and zinc sulfate filtrate. 11. A method for recovering metal from dust ash or its crude zinc oxide as described in claim 7, wherein the ferric hydroxide-containing acidic filtrate is filtered after the iron hydroxide precipitation to obtain hydrogen respectively. Iron oxide and zinc sulphate sputum. 12. A method of recovering metal from dust ash or its crude oxygen 201109445 zinc as described in claim 8 wherein zinc sulphate is obtained by electrolysis of zinc sulphate to obtain metal zinc. ^ 13. A method for recovering metal from dust ash or its crude oxidation word as described in claim 9 wherein zinc sulphate is obtained after electrolysis to obtain metal ^ claws 14. The method for recovering metal from dust collecting ash or its crude zinc oxide according to the first aspect of the patent range, wherein after obtaining zinc sulfate, the cerium comprises electrolyzing zinc sulphate to obtain metal zinc. Melon I5. A method for recovering metal from dust ash or its crude oxygen as described in the above-mentioned claim, wherein after obtaining zinc sulfate, the zinc is further subjected to electrolysis to obtain metal zinc. In the case of the money 1φ6 h, please refer to the method of recovering metal from the dust collection ash or its crude oxygen=zinc according to the eighth item of the patent scope. After obtaining the zinc sulfate, the schematic includes precipitating the furnace and sodium hydroxide to Obtained zinc oxide. Μ2: 1 Γ 范围 范围 范围 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 . According to the tenth item of the patented dry 胄 月 从 从 从 或其 或其 或其 或其 或其 或其 或其 或其 或其 或其 或其 或其 或其 或其 或其 或其 或其 或其 或其 或其 : : : : : : : : : : : : : : : : : Zinc. In the zinc sinter patent (4), in the eleventh item, the sulphuric acid and the gas oxidized nano-recycling metal from the dust-collecting ash or the crude oxygen-removing metal are subjected to the sulphate sulphide, After the crude oxygen is obtained, after the iron hydroxide is obtained, the high temperature 12 • 201109445 is further dried to obtain the iron oxide. * The method of recovering metal from the ash or its crude oxidized chemistry as described in item 9 of the U Scope, wherein after obtaining the oxidized iron, the iron hydroxide is further dried at a high temperature to obtain iron oxide. A method for recovering metal from dust collecting ash or its crude zinc oxide as described in claim 10, wherein after obtaining iron hydroxide, the iron hydroxide is further dried at a high temperature to obtain iron oxide. 23. A method of recovering metal from dust ash or its crude zinc oxide as described in the scope of claim 5, wherein after obtaining iron hydroxide, the iron hydroxide is further dried at a high temperature to obtain iron oxide. Schema: (such as the next page) 13