A method for resource processing of iron-containing raw materials

Abstract

The present application relates to a kind of resource processing method of iron-containing raw material, when iron, zinc in solution is separated, by jointly using zinc protective agent and iron morphology control agent, adjust pH and pass into oxidizing agent, make iron ion precipitate in the form of iron oxide, reduce the adsorption amount of zinc in the process of iron oxide precipitation, reduce the zinc content in iron powder.In the leaching of lead and calcium in lead-calcium slag, a leaching solution containing lead-strengthening solvent, calcium solvent and calcium-solvent is used, which makes gypsum and lead sulfate enter the solution at the same time, then by adjusting pH, calcium is combined with sulfate again to precipitate as gypsum, and under the dual action of high pH (6-12) and lead-strengthening solvent, lead is left in the solution, thereby reducing the lead content in gypsum and achieving the purpose of separating calcium and lead.The present application realizes the separation of zinc and iron in the wet system and converts them into iron compounds and zinc salts, improving the purity of the products, so as to be further processed as qualified products or iron / zinc concentrate raw materials.

Description

Technical Field

[0001] This invention relates to the field of resource utilization technology for iron-containing raw materials. Background Technology

[0002] In lead-zinc smelting, various iron-containing waste residues are generated, including zinc leaching residue, iron alum slag, and iron-containing neutralization slag. These waste residues lack effective treatment methods due to their high iron content and complex composition. Zinc leaching residue refers to the residue produced after roasting and leaching zinc-containing raw materials during zinc smelting. Typically, zinc-containing raw materials can be zinc concentrate, zinc slag, or zinc oxide ore. During leaching, acidic solutions such as sulfuric acid and ammonium chloride are usually used to dissolve the zinc ions, forming a zinc-containing solution. After leaching, the residue is separated. The residue still contains certain amounts of metallic elements such as zinc, lead, copper, and iron, as well as non-metallic elements such as silicon, aluminum, calcium, and magnesium. Because of the high zinc content in the residue, it is called zinc leaching residue.

[0003] The zinc content varies in zinc-containing raw materials such as zinc concentrate, zinc slag, and zinc oxide ore, resulting in different zinc contents in zinc leaching residue. Generally, the zinc content in zinc leaching residue is around 20-30% (some zinc leaching residues have zinc contents as low as below 10%), the lead content is usually 5-15%, the silica content is usually 10-20%, and the iron content is usually 15-25%. Zinc in zinc leaching residue exists in the forms of zinc oxide and zinc sulfide, but also in small amounts in other forms. Lead, silicon, and ferrosilicon are the main elements in zinc leaching residue, and their specific contents are related to factors such as the source of raw materials and leaching conditions. Zinc leaching residue contains various harmful and valuable elements, posing potential impacts on the environment and resources. Therefore, the treatment of zinc leaching residue has always been a research hotspot in the field of zinc metallurgy. Currently, the main methods for treating zinc leaching residue include pyrometallurgical treatment, which recovers the useful components.

[0004] Pyrometallurgical treatment refers to a process that separates the target metal by heating, melting, or oxidizing raw materials at high temperatures. This mainly includes side-blown furnace processes, fuming furnace processes, and rotary kiln processes. Among these, a side-blown furnace is a processing device that uses an oxygen flow to separate waste residue and metal under high-temperature conditions. The side-blown furnace process for zinc leaching residue generally includes the following steps: ① crushing the zinc leaching residue; ② feeding the crushed zinc leaching residue into a side-blown furnace, where the metal in the residue is separated from the slag using an oxygen flow under high-temperature conditions, generating metal shavings and gaseous waste gas; ③ collecting and processing the generated metal shavings, using methods such as magnetic separation and flotation to separate non-ferrous metals and iron; ④ purifying the generated gaseous waste gas through dust removal, desulfurization, and other treatments. Although the side-blown furnace process can separate valuable elements from zinc leaching residue, it has high energy consumption, requires a large amount of oxygen, and is costly. It is also prone to secondary pollution, as the waste gas may contain harmful substances such as sulfur dioxide, which can easily cause secondary pollution during further treatment.

[0005] A rotary kiln is a rotating cylinder used to heat, dry, and calcine materials. The process of treating zinc leaching slag in a rotary kiln generally includes: ① removing impurities and moisture; ② feeding the slag into the rotary kiln; ③ high-temperature calcination, which allows the useful substances in the zinc leaching slag to separate and be recovered, but also generates a large amount of waste gas and dust; ④ discharging the calcined product from the rotary kiln, cooling and pulverizing it to obtain the final product; ⑤ waste gas treatment: harmlessly treating the waste gas and dust generated by the rotary kiln. Although rotary kiln treatment is highly efficient and has a high recovery rate, and is relatively environmentally friendly, its energy consumption is still high. The electricity and fuel consumption for heating the rotary kiln is significant, and improper operation can easily lead to accidents. Furthermore, treating zinc leaching slag in a rotary kiln requires the construction of a dedicated production line and equipment, resulting in high investment costs.

[0006] In summary, current methods for treating zinc leaching residue (including other iron-containing raw materials) typically involve pyrometallurgical processes (including side-blown furnaces, flue gas furnaces, and rotary kilns). These processes heat the raw materials to approximately 1000°C, utilizing the high melting points and low volatility of elements such as iron, calcium, magnesium, and silicon to separate more volatile elements like lead and zinc in gaseous form. While this method can recover lead and zinc from iron-containing raw materials, it suffers from the following problems:

[0007] (1) Elements such as iron, calcium, magnesium, and silicon cannot be separated from each other and will form eutectic waste residue. The iron content in the waste residue is low and cannot meet the requirements of iron concentrate powder, so the iron element in the waste residue cannot be recovered.

[0008] (2) Lead and zinc are recovered in the form of gas and then enriched into secondary zinc oxide by condensation. However, secondary zinc oxide contains lead and zinc compounds, and the composition is random and not fixed. Secondary processing is required to obtain industrial products of lead and zinc.

[0009] (3) For iron-containing raw materials containing sulfates, sulfur will be converted into acidic gases such as sulfur dioxide during the pyrometallurgical recovery process. The exhaust gas needs to be purified through exhaust gas treatment, which will cause potential environmental pollution and high environmental protection treatment costs.

[0010] Despite the numerous problems with pyrometallurgical processes, most iron-containing raw materials are still processed using this method. The main reason is that in existing hydrometallurgical systems, zinc and iron are easily co-deposited, and there is a lack of effective methods to separate the zinc and iron elements in the solution. This results in zinc and iron products with low purity, failing to meet the required product quality. Summary of the Invention

[0011] (a) Technical problems to be solved

[0012] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a resource-based treatment method for iron-containing raw materials. By adding appropriate solvents and designing specific treatment steps, zinc and iron in the solution can be separated and converted into products that meet national standards, thus solving the problem of difficult separation of zinc and iron in wet processing.

[0013] (II) Technical Solution

[0014] This invention provides a method for the resource utilization of iron-containing raw materials, comprising:

[0015] S1. Iron-containing raw materials are mixed with acid solutions to leach out metal element M from the iron-containing raw materials. Metal element M is a metal element that can combine with acid to form a soluble salt. After leaching, metal element M enters the acid hydrolysis solution to obtain acid hydrolysis solution and lead-calcium slag. Metal element M includes zinc, iron, manganese, magnesium, cadmium, nickel and copper. The reaction temperature is 0-110℃ and the pH value is -2 to 3.

[0016] S2. The acid hydrolysate is subjected to one or more of the following methods: temperature-controlled crystallization, concentrated crystallization, and addition of inert salt, so that some of the zinc, iron, manganese, magnesium, cadmium, nickel, and copper elements in the acid hydrolysate crystallize into precipitates. After solid-liquid separation, iron-containing precipitate and crystallization mother liquor are obtained.

[0017] The iron-containing precipitate is a sulfate, nitrate, chloride, perchlorate, or acetate containing zinc and iron elements; or the iron-containing precipitate is a double sulfate, double nitrate, chloride, perchlorate, or acetate containing zinc and iron alkali salt ions; the alkali salt ions are potassium, sodium, or ammonium ions;

[0018] S3. Add the iron-containing precipitate or its aqueous solution to the iron precipitation solution, and introduce an oxidant to carry out an oxidation reaction. The iron element is converted into iron oxide powder. After separation, the zinc element is retained in the iron removal solution, and iron oxide powder and iron removal solution are obtained. The iron precipitation solution contains a zinc protectant, an iron morphology control agent and an inert salt. The reaction temperature is 0 to 110°C and the pH value is 5-13.

[0019] The iron oxide powder is one or a combination of two or more of iron hydroxide, iron oxide, iron(III) oxide, and hydrated iron oxide;

[0020] The oxidant is one or a combination of two or more of air, oxygen, hydrogen peroxide, potassium permanganate, manganese dioxide, and lead dioxide; the zinc protectant is a complexing agent capable of forming a strong complex with zinc ions, wherein the valence state of the formed zinc complex ions is greater than +2 or less than -2; the iron morphology control agent is a complexing agent capable of forming a weak complex with ferric ions, wherein the concentration of the formed iron complex ions in the iron precipitation solution is less than 1*10⁻⁶. -5 Complexing agent at mol / L;

[0021] S4. Remove zinc from the iron removal solution generated in S3 by zinc salt precipitation or electrolysis;

[0022] The electrolysis method involves passing direct current into the iron removal solution, which produces metallic zinc at the cathode.

[0023] The zinc salt precipitation method is as follows: by adjusting the pH and / or temperature of the iron removal solution, the zinc in the iron removal solution is converted into zinc salt precipitate, and a zinc removal solution is obtained (manganese, magnesium, cadmium, nickel and copper remain in it); the reaction temperature is 0 to 110℃, and the pH value is 4 to 12;

[0024] S5. Dissolve the zinc salt precipitate in a circulating carbonization solution containing zinc solvent, control the pH value between 6.0 and 12.0, and then filter to remove impurities to obtain a purified zinc solution; adjust the pH value of the purified zinc solution to 5.0-11.0, and perform carbonization treatment to convert zinc into zinc carbonate precipitate and circulating carbonization solution. The circulating carbonization solution is recycled in this step.

[0025] According to a preferred embodiment of the present invention, when the iron-containing raw material contains lead-calcium compounds, the present invention further includes steps S6-S8:

[0026] S6. The lead-calcium slag produced in S1 is mixed and reacted with a leachate containing lead-enhancing solvent, calcium solvent, calcium co-solvent and inert salt to dissolve the lead and calcium elements in the lead-calcium slag. After separation, tailings and lead-calcium solution are obtained. The reaction temperature is 0 to 110℃ and the pH value is 7 to 13.

[0027] The lead-enhancing solvent is a sulfur-containing complexing agent with strong complexing ability for lead ions; the lead-enhancing solvent is one or a combination of two or more of cysteine, cystine, mercaptopropionic acid, mercaptopropanol, mercaptoethanol, mercaptomethionine, methimazole, etc., and the amount added to the reaction system is 0.01-500 g / L.

[0028] S7. Adjust the pH of the lead-calcium solution generated in S6 to 6-12 (lead sulfate precipitation is accelerated when the pH is below 5 and below 4, and the precipitation is fastest when the pH is below 3; at the same time, use lead-enhanced solvent to prevent lead from precipitating), so that the calcium in the solution is separated in the form of calcium sulfate, and gypsum precipitate and lead-containing solution are obtained; the gypsum precipitate is one or a combination of two or more of calcium sulfate dihydrate, calcium sulfate hemihydrate, and anhydrous calcium sulfate.

[0029] S8. A carbon source is introduced into the lead-containing solution produced in S7 to convert the lead into lead carbonate precipitate. After separation, lead carbonate and circulating leachate are obtained. The circulating leachate is returned to S6 as leachate.

[0030] The carbon source is one or a combination of two or more of carbon dioxide, sodium carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, potassium carbonate, and potassium bicarbonate, and the amount added to the reaction system is 0.01-500 g / L.

[0031] It should be noted that in step S1, zinc, iron, manganese, magnesium, cadmium, nickel, and copper are leached from the iron-containing raw material through acid leaching and separated from the lead-calcium slag. In step S2, the solution of zinc, iron, manganese, magnesium, cadmium, nickel, and copper is precipitated out as iron-containing raw material through crystallization. In step S3, iron and zinc are separated from the iron-containing raw material, and iron is extracted. Steps S4-S5 extract zinc from the iron-containing raw material, steps S6-7 extract calcium from the lead-calcium slag, and step S8 extracts lead from the lead-calcium slag. That is, steps S6-8 treat the lead-calcium slag, and steps S2-5 treat the acid leaching solution containing zinc, iron, manganese, magnesium, cadmium, nickel, and copper. Therefore, steps S6-8 can be performed in parallel with steps S2-5, or steps S6-8 can be performed before steps S2-5.

[0032] Since step S2-5 is mainly used to solve the problem of the difficulty in separating iron and zinc in solutions containing both iron and zinc, when the iron-containing raw material in S1 does not contain lead-calcium compounds, step S2-5 can obtain iron oxide powder and zinc carbonate precipitate that can be used as concentrates, and in this case, the operation of step S6-8 is not necessary.

[0033] In this application, inert salt refers to a soluble salt mainly used to control the total ion concentration (increase ion potential) of the reaction system. Inert salt usually does not directly participate in the reaction, but it can interfere with the reaction rate and the degree of reaction completion by increasing the total concentration of soluble ions, such as promoting the leaching rate, crystallization rate / crystallization rate, or preventing iron ions from combining into stable complexes, thereby improving the iron ion oxidation rate and the separation efficiency of iron and zinc.

[0034] According to a preferred embodiment of the present invention, in S1, the acid solution is one or a combination of two or more of the following: sulfuric acid solution, nitric acid solution, sulfurous acid solution, perchloric acid solution, and hydrochloric acid solution.

[0035] The iron-containing raw material is a waste residue containing zinc and iron elements. The waste residue includes one or more of the following: iron-containing neutralization slag, iron alum slag, zinc leaching slag, secondary zinc oxide, steelmaking fly ash, and zinc-containing furnace ash generated during lead / zinc / copper smelting.

[0036] According to a preferred embodiment of the present invention, in step S1, an inert salt and a catalyst are added to the acid solution; the catalyst is one or a combination of two or more of cobalt, manganese sulfates, nitrates, chlorides, perchlorates, acetates, and carbonates, and the amount added to the reaction system is 0.01-500 g / L; the inert salt is one or a combination of two or more of potassium / sodium / ammonium / ferric / ferrous / zinc sulfates, nitrates, chlorides, perchlorates, acetates, and carbonates, and the amount added to the reaction system is 0.01-500 g / L. By adding salt and catalyst in step S1, a better leaching effect is achieved, including increasing the leaching rate and leaching yield.

[0037] According to a preferred embodiment of the present invention, in S2, the crystallization temperature is -30 to 90°C; the inert salt is one or a combination of two or more of potassium / sodium / ammonium sulfates, nitrates, chlorides, perchlorates, acetates, and carbonates, and the amount added to the reaction system is 0.01-500 g / L.

[0038] According to a preferred embodiment of the present invention, in S3, the zinc protective agent is one or a combination of two or more of the following: ethylenediamine, propylenediamine, hydroxyethylethylenediaminetriacetic acid, hydroxyethylidene diphosphate, aminotrimethylidene phosphate, diethylenetriaminepentamethylidene phosphate, tripolyphosphate, pyrophosphate, ethylenediaminetetraacetic acid, propylenediaminediacetic acid, ethylenediaminediacetic acid, ethylene glycol diethyl ether diaminetetraacetic acid, diethyl ether diaminetetraacetic acid, propylenediaminetetraacetic acid, hydroxyethylethylenediaminetriacetic acid, 2-aminobenzoic acid-N,N-diacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraaminehexaacetic acid, cyclohexanediaminetetraacetic acid, diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, sodium catechol-3,5-disulfonate, xylenol orange, and catechol purple; the amount added to the reaction system is 0.01-500 g / L.

[0039] The iron morphology control agent is one or a combination of two or more of the following: glutamic acid, valine, histidine, aspartic acid, leucine, isoleucine, alanine, proline, serine, phenylalanine, arginine, threonine, glycine, lysine, asparagine, glutamine, methionine, ornithine, taurine, citrulline, sarcosine, acetic acid, phthalic acid, and nicotinic acid, and the amount added to the reaction system is 0.01-500 g / L.

[0040] The inert salt is one or a combination of two or more of the following: potassium / sodium / ammonium sulfates, nitrates, chlorides, perchlorates, acetates, and carbonates, and the amount added to the reaction system is 0.01-500 g / L.

[0041] According to a preferred embodiment of the present invention, in S4, the zinc salt precipitate is a zinc-containing sulfate, nitrate, chloride, perchlorate, or acetate; or,

[0042] The zinc salt precipitate is a sulfate double salt, nitrate double salt, chloride, perchloric acid double salt, or acetic acid double salt containing zinc and potassium / sodium / ammonium ions;

[0043] In S5, the reaction temperature is between 0 and 110°C; the zinc solvent is one or a combination of two or more of ammonia, ethylamine, propylamine, imidazole, and ethylenediamine, and the amount added to the reaction system is 0.01-500 g / L.

[0044] According to a preferred embodiment of the present invention, in S6, the calcium solvent is one or a combination of two or more of the following: hydroxyethyl ethylenediamine triacetic acid, hydroxyethylidene diphosphate, aminotrimethylidene phosphate, diethylenetriaminepentamethylidene phosphate, tripolyphosphate, pyrophosphate, ethylenediaminetetraacetic acid, propylenediamine diacetic acid, ethylenediamine diacetic acid, ethylene glycol diethyl ether diaminetetraacetic acid, diethyl ether diaminetetraacetic acid, propylenediaminetetraacetic acid, hydroxyethyl ethylenediamine triacetic acid, 2-aminobenzoic acid-N,N-diacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraaminehexaacetic acid, cyclohexanediaminetetraacetic acid, and aminotriacetic acid, and the amount added to the reaction system is 0.01-500 g / L;

[0045] The calcium co-solvent is one or a combination of two or more of the sulfates, chlorides, nitrates, and perchlorates of sodium, potassium, ammonium, magnesium, calcium, zinc, manganese, nickel, copper, cadmium, and lead ions, and the amount added to the reaction system is 0.01-500 g / L; the inert salt is one or a combination of two or more of the sulfates, nitrates, chlorides, perchlorates, acetates, and carbonates of potassium, sodium, ammonium, calcium, and magnesium, and the amount added to the reaction system is 0.01-500 g / L.

[0046] According to a preferred embodiment of the present invention, the pH is adjusted in S1, S3, S4, S5 and S6 by using an organic base, an inorganic base, an organic acid or an inorganic acid to control the pH value of the solution.

[0047] The organic base is one or more of methylamine, ethylamine, ethylenediamine, propylenediamine, and propylamine; the inorganic base is one or more of ammonia, potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, ammonium carbonate, calcium oxide, and calcium hydroxide; the organic acid is one or more of formic acid, acetic acid, oxalic acid, propionic acid, and citric acid; and the inorganic acid is one or more of sulfuric acid, hydrochloric acid, nitric acid, perchloric acid, and phosphoric acid.

[0048] In step S7, the pH value of the solution is adjusted by evaporating alkaline gas to cause calcium to precipitate in the form of gypsum; the alkaline gas is ammonia, monoethanolamine, ethylenediamine, ethylamine or methylamine, and the alkaline gas generated by evaporation is directly recycled or converted back into alkali through condensation absorption for pH adjustment in S1, S3, S4, S5 and S6.

[0049] According to a preferred embodiment of the present invention, when the iron-containing raw material in S1 is a solution containing iron and zinc, the acid leaching in step S1 and the crystallization precipitation treatment in step S2 are omitted. The iron-containing solution is directly used as the starting material for step S3, and the processes in steps S3-S5 are performed. That is, the iron-containing solution is added to the iron precipitation solution, and an oxidizing agent or the like is introduced for subsequent processing.

[0050] According to a preferred embodiment of the present invention, step S2 is omitted, that is, the acid hydrolysate generated in S1 is used as the starting material for step S3 and processed in accordance with steps S3-S5.

[0051] According to a preferred embodiment of the present invention, the crystallization mother liquor generated in step S2 is further used as the starting material for step S3 and processed in accordance with steps S3-S5.

[0052] (III) Beneficial Effects

[0053] This invention improves the existing wet process system, achieving the separation of iron and zinc in the wet process system. The separated iron oxide powder and zinc carbonate precipitate have high grades and can be used as iron or zinc concentrate for further purification.

[0054] In step S1, this invention improves the leaching rate and extraction rate of zinc, iron, manganese, magnesium, cadmium, and copper from iron-containing raw materials by adding inert salts, catalysts, and one or more combinations of sulfates, nitrates, chlorides, perchlorates, acetates, and carbonates of potassium, sodium, ammonium, ferric iron, ferrous iron, zinc, zinc, nitrates, chlorides, perchlorates, acetates, and carbonates to the acid solution (sulfuric acid, nitric acid, sulfurous acid, perchloric acid, or hydrochloric acid). In step S2, the total purity of zinc, iron, manganese, magnesium, cadmium, nickel, and copper elements in the iron-containing precipitate is improved by crystallization. In step S3, zinc protectant, iron morphology control agent, and inert salts are added to the precipitation solution, while an oxidant is introduced to selectively protect zinc and convert iron ions into iron oxide powder, thereby separating zinc and iron under solution conditions. The iron oxide powder is used as a product output or as a raw material for further purification of iron concentrate. In step S4, zinc ions are converted into zinc salt precipitate through electrolytic reduction or zinc salt precipitation and adjustment to a suitable pH, thus separating zinc ions from ions such as manganese, magnesium, cadmium, nickel, and copper. In step S5, the zinc salt precipitate is dissolved in a solution containing zinc solvent, controlling the pH value between 6.0 and 12.0, allowing zinc to enter the solution as water-soluble ions. After filtration to remove impurities, a purified zinc solution is obtained. This step removes impurities such as manganese, magnesium, cadmium, nickel, and copper introduced during the zinc salt precipitation process in S4. The purified zinc solution is then further adjusted to make zinc an amphoteric metal, allowing it to dissolve again in the solution. Carbonation treatment converts zinc into zinc carbonate precipitate, thereby increasing the purity of zinc carbonate for use as a product or as a raw material for further purification of zinc concentrate. In step S6, the lead-calcium slag produced by acid leaching in S1 is redissolved in a leaching solution containing lead-enhancing solvent, calcium solvent, calcium co-solvent, and inert salts to obtain tailings and a lead-calcium solution; substances that cannot be redissolved are included in the tailings. In step S7, the pH of the solution is adjusted to 6-12 by evaporating alkaline gas. Based on the fact that the pH ranges for lead sulfate and calcium sulfate precipitation do not overlap, a lead-enhanced solvent is used to prevent lead precipitation, causing calcium sulfate (gypsum) to precipitate, while the lead remains in the solution, resulting in a lead-containing solution. In step S8, the lead-containing solution is carbonated to obtain lead carbonate. Lead carbonate is then used as a product for output or as a raw material for further purification of lead concentrate. Attached Figure Description

[0055] Figure 1 This is a flowchart of a method for resource recovery of iron-containing raw materials according to the present invention. Detailed Implementation

[0056] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0057] The technical difficulties to be overcome by this invention include:

[0058] ① The process of reacting iron-containing raw materials with an acidic solution to dissolve zinc and iron into the solution is relatively simple. However, separating the zinc and iron in the solution is a major challenge in hydrometallurgy. The precipitation process of iron in the solution mainly involves: iron ions first forming ferric hydroxide colloids, which then aggregate and dehydrate to obtain iron oxide, thus yielding iron concentrate mainly composed of iron oxide. During the precipitation process, iron, being a high-valence metal hydroxide, easily forms colloids. Therefore, zinc in the solution is easily adsorbed onto the surface of the ferric hydroxide colloids. During the dehydration process of ferric hydroxide, zinc is deposited on the surface of iron oxide in an adsorbed form, replacing some iron ions and forming zinc ferrite. This results in the produced iron concentrate always containing 2-5% zinc. Since zinc is a harmful element in the ironmaking industry, iron concentrate produced by conventional methods cannot be used as a raw material for ironmaking.

[0059] To address this technical challenge, this invention proposes the combined use of an iron morphology control agent and a zinc protectant in an iron-zinc mixed solution. This isolates the surface of ferric hydroxide from zinc ions, thereby controlling the zinc content in the iron concentrate and resulting in a lower zinc impurity content in the iron concentrate separated in step S3. The iron morphology control agent (organic complexing agent) has a certain complexing ability (weak complexing) for iron. The organic complexing agent adsorbs on the surfaces of ferric hydroxide and iron oxide, forming an organic isolation layer. This organic isolation layer inhibits the adsorption of zinc ions and promotes the growth of iron oxide particles, resulting in a coarser iron concentrate product that is easier to filter. On the other hand, the zinc protectant has a strong complexing ability (strong complexing) for zinc, and the formed zinc complex is a highly charged molecule that forms electrostatic repulsion with the organic isolation layer of the iron colloid, further isolating the surface collisions between zinc and the iron colloid. The zinc protectant, through strong complexation and electrostatic isolation, prevents iron colloids from contacting zinc ions and adsorbing zinc during dehydration crystallization and crystal growth. Therefore, the resulting iron concentrate has an extremely low zinc content, meeting the zinc requirements for iron concentrate used in steel smelting. After iron precipitation, the zinc in the solution can be separated by electrolysis or crystallization, thus achieving the separation of zinc and iron.

[0060] ② After the iron-containing raw material is leached with an acid solution (step S1), soluble elements such as zinc, copper, iron, manganese, and magnesium are recovered in the acid hydrolysis solution, while elements such as lead, calcium, and silicon remain in the slag in the form of lead sulfate, calcium sulfate, and silicon dioxide. The separation of lead sulfate, calcium sulfate, and silicon dioxide is also a major challenge in hydrometallurgy.

[0061] To address this technical challenge, in step S6 of this invention, the combined action of lead-enhancing solvent, calcium solvent, and calcium co-solvent is utilized to dissolve lead sulfate simultaneously with gypsum dissolution. Lead and calcium contained in the lead-calcium slag (containing lead sulfate, calcium sulfate, and silica, etc.) are selectively leached into the solution, yielding a lead-calcium solution. Then, the solution pH is adjusted to 6-12. Taking advantage of the fact that lead sulfate precipitates more readily below pH 5.5, and utilizing the strong complexing ability of the lead-enhancing solvent for lead, lead ions are prevented from crystallizing along with the gypsum during the gypsum crystallization process, ensuring that lead remains in the solution and thus guaranteeing the quality of the gypsum product. On the other hand, carbon dioxide has the ability to compete for lead ions in the lead complex of the lead-enhancing solvent, causing the lead ions to convert into lead carbonate precipitate, thereby obtaining a high-quality lead carbonate product. Therefore, this invention utilizes the combined action of lead-enhancing solvent, calcium solvent, and calcium co-solvent to solve the problems of the poor solubility and separation of calcium sulfate and lead sulfate, resulting in high-quality gypsum and lead concentrate products.

[0062] like Figure 1 The diagram shown is a flowchart of a method for resource recovery of iron-containing raw materials according to the present invention.

[0063] S1. Iron-containing raw materials are mixed with acid solutions to leach out metal element M from the iron-containing raw materials. Metal element M is a metal element that can combine with acid to form a soluble salt. After leaching, metal element M enters the acid hydrolysis solution to obtain acid hydrolysis solution and lead-calcium slag. Metal element M includes zinc, iron, manganese, magnesium, cadmium, nickel and copper. The reaction temperature is 0-110℃ and the pH value is -2 to 3.

[0064] S2. The acid hydrolysate is subjected to one or more of the following methods: temperature-controlled crystallization, concentrated crystallization, and addition of inert salt, so that some of the zinc, iron, manganese, magnesium, cadmium, nickel, and copper elements in the acid hydrolysate crystallize into precipitates. After solid-liquid separation, iron-containing precipitate and crystallization mother liquor are obtained.

[0065] The iron-containing precipitate is a sulfate, nitrate, chloride, perchlorate, or acetate containing zinc and iron elements; or the iron-containing precipitate is a double sulfate, double nitrate, chloride, perchlorate, or acetate containing zinc and iron alkali salt ions; the alkali salt ions are potassium, sodium, or ammonium ions;

[0066] S3. Add the iron-containing precipitate or its aqueous solution to the iron precipitation solution, and introduce an oxidant to carry out an oxidation reaction. The iron element is converted into iron oxide powder. After separation, the zinc element is retained in the iron removal solution, and iron oxide powder and iron removal solution are obtained. The iron precipitation solution contains zinc protectant, iron morphology control agent and inert salt. The reaction temperature is 0 to 110℃ and the pH value is 5-13.

[0067] The iron oxide powder is one or a combination of two or more of iron hydroxide, iron oxide, iron(III) oxide, and hydrated iron oxide;

[0068] The oxidant is one or a combination of two or more of air, oxygen, hydrogen peroxide, potassium permanganate, manganese dioxide, and lead dioxide; the zinc protectant is a complexing agent capable of forming a strong complex with zinc ions, wherein the valence state of the formed zinc complex ions is greater than +2 or less than -2; the iron morphology control agent is a complexing agent capable of forming a weak complex with ferric ions, wherein the concentration of the formed iron complex ions in the iron precipitation solution is less than 1*10⁻⁶. -5 Complexing agent at mol / L;

[0069] S4. Remove zinc from the iron removal solution generated in S3 by zinc salt precipitation or electrolysis;

[0070] The electrolysis method involves passing direct current into the iron removal solution, which produces metallic zinc at the cathode.

[0071] The zinc salt precipitation method is as follows: by adjusting the pH and / or temperature of the iron removal solution, the zinc in the iron removal solution is converted into zinc salt precipitate, and a zinc removal solution is obtained (manganese, magnesium, cadmium, nickel and copper remain in it); the reaction temperature is 0 to 110℃, and the pH value is 4 to 12;

[0072] S5. Dissolve the zinc salt precipitate in a circulating carbonization solution containing zinc solvent, control the pH value between 6.0 and 12.0, and then filter to remove impurities to obtain a purified zinc solution; adjust the pH value of the purified zinc solution to 5.0-11.0, and perform carbonization treatment to convert zinc into zinc carbonate precipitate and circulating carbonization solution. The circulating carbonization solution is recycled in this step.

[0073] According to a preferred embodiment of the present invention, when the iron-containing raw material contains lead-calcium compounds, the present invention further includes steps S6-S8:

[0074] S6. The lead-calcium slag produced in S1 is mixed and reacted with a leachate containing lead-enhancing solvent, calcium solvent, calcium co-solvent and inert salt to dissolve the lead and calcium elements in the lead-calcium slag. After separation, tailings and lead-calcium solution are obtained. The reaction temperature is 0 to 110℃ and the pH value is 7 to 13.

[0075] The lead-enhancing solvent is a sulfur-containing complexing agent with strong complexing ability for lead ions; the lead-enhancing solvent is one or a combination of two or more of cysteine, cystine, mercaptopropionic acid, mercaptopropanol, mercaptoethanol, mercaptomethionine, methimazole, etc., and the amount added to the reaction system is 0.01-500 g / L.

[0076] S7. Adjust the pH of the lead-calcium solution produced in S6 to 6-12 (lead sulfate precipitation is faster when the pH is below 5.5 and below 4, and fastest when the pH is below 3), so that the calcium in the solution is separated in the form of calcium sulfate, and gypsum precipitate and lead-containing solution are obtained; the gypsum precipitate is one or more of dihydrate calcium sulfate, hemihydrate calcium sulfate, and anhydrous calcium sulfate.

[0077] S8. A carbon source is introduced into the lead-containing solution produced in S7 to convert the lead into lead carbonate precipitate. After separation, lead carbonate and circulating leachate are obtained. The circulating leachate is returned to S6 as leachate.

[0078] The carbon source is one or a combination of two or more of carbon dioxide, sodium carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, potassium carbonate, and potassium bicarbonate, and the amount added to the reaction system is 0.01-500 g / L.

[0079] It should be noted that in step S1, zinc, iron, manganese, magnesium, cadmium, nickel, and copper are leached from the iron-containing raw material through acid leaching and separated from the lead-calcium slag. In step S2, the solution of zinc, iron, manganese, magnesium, cadmium, nickel, and copper is precipitated out as iron-containing raw material through crystallization. In step S3, iron and zinc are separated from the iron-containing raw material, and iron is extracted. Steps S4-S5 extract zinc from the iron-containing raw material, steps S6-7 extract calcium from the lead-calcium slag, and step S8 extracts lead from the lead-calcium slag. That is, steps S6-8 treat the lead-calcium slag, and steps S2-5 treat the acid leaching solution containing zinc, iron, manganese, magnesium, cadmium, nickel, and copper. Therefore, steps S6-8 can be performed in parallel with steps S2-5, or steps S6-8 can be performed before steps S2-5.

[0080] Since step S2-5 is mainly used to solve the problem of the difficulty in separating iron and zinc in solutions containing both iron and zinc, when the iron-containing raw material in S1 does not contain lead-calcium compounds, step S2-5 can obtain iron oxide powder and zinc carbonate precipitate that can be used as concentrates, and in this case, the operation of step S6-8 is not necessary.

[0081] Furthermore, when the iron-containing raw material in S1 is a solution containing iron and zinc, the acid leaching in step S1 and the crystallization precipitation in step S2 can be omitted, and the iron- and zinc-containing solution can be directly used as the starting material for step S3, proceeding with steps S3-S5. Alternatively, step S2 can be omitted, i.e., the acid hydrolysate generated in S1 can be used as the starting material for step S3, proceeding with steps S3-S5. Or, the present invention further uses the crystallization mother liquor generated in step S2 as the starting material for step S3, proceeding with steps S3-S5.

[0082] The main technical problem this invention aims to solve is how to separate and convert zinc and iron in a wet process system into iron compounds and zinc salts, thereby improving their purity so that they can be used as qualified products or iron / zinc concentrate raw materials for further processing. Simultaneously, if the iron-containing raw material contains lead and calcium compounds, the invention further extracts and separates valuable elements such as lead and calcium, converting them into qualified products or lead concentrate raw materials.

[0083] The features and technical effects of the present invention will be illustrated below with reference to specific embodiments. Unless otherwise specified, % in the following embodiments refers to mass percentage.

[0084] Example 1

[0085] This embodiment describes a method for processing raw materials containing zinc, lead, calcium, and iron, including the following steps:

[0086] (1) Add 5 kg of zinc leaching residue to 50 L of aqueous solution containing 10 g / L ferrous sulfate and 20 g / L zinc sulfate, adjust the pH value to -0.5 with sulfuric acid, react at 80 °C for 5 hours, and then separate the acid hydrolysate and lead-calcium residue.

[0087] (2) The obtained acid hydrolysate is crystallized at 0°C for 2 hours, and then the iron-containing precipitate and crystallization liquid containing zinc sulfate and ferric sulfate are separated. The crystallization liquid is returned to step (1) for recycling.

[0088] (3) The obtained iron precipitate was dissolved in 1 part water to form a solution. The solution was then gradually added to an iron precipitation solution containing 100 g / L ethylenediamine, 200 g / L phenylalanine and 50 g / L ammonium sulfate. The pH was adjusted to 7.0 with ammonia water, oxygen was introduced, and the reaction was carried out at 100°C for 5 hours. The mixture was then separated to obtain an iron concentrate product containing 60% iron and 0.1% zinc, as well as an iron removal solution.

[0089] (4) The obtained iron removal solution is used to obtain metallic zinc at the cathode by electrolysis using a 100 square centimeter graphite cathode.

[0090] (5) The lead-calcium slag obtained in step (1) is added to a leachate containing 50 g / L cysteine, 150 g / L hydroxyethylidene diphosphate, 50 g / L copper sulfate and 100 g / L ammonium sulfate. The pH is adjusted to 10.0 with sodium hydroxide. After reacting at 60°C for 5 hours, the residue and lead-calcium solution are separated to obtain tailings and lead-calcium solution.

[0091] (6) The lead-calcium solution obtained in step (5) is boiled and evaporated at 100°C, the pH value is adjusted to 8.0, and the solution is separated after reacting for 5 hours to obtain gypsum dihydrate with a purity of 99% and lead-containing solution.

[0092] (7) The lead-containing solution obtained in step (6) is introduced into carbon dioxide gas and reacted at 90°C for 5 hours. The solution is then separated to obtain a lead carbonate product with a purity of 98% and a circulating leachate. The circulating leachate is returned to step (5) as a leachate for recycling.

[0093] Example 2

[0094] This embodiment describes a method for processing raw materials containing zinc, lead, calcium, and iron, including the following steps:

[0095] (1) Add 10 kg of iron alum slag to 50 L of aqueous solution containing 100 g / L zinc sulfate, adjust the pH value to 1 with sulfuric acid, introduce sulfur dioxide gas, react at 70 °C for 3 hours, and then separate the acid hydrolysate and lead-calcium slag.

[0096] (2) The acid hydrolysate obtained in step (1) is crystallized at 30°C for 20 hours. Then, an iron-containing precipitate and crystallization solution containing zinc sulfate and ferrous sulfate are separated. The crystallization solution is returned to step 1 for recycling.

[0097] (3) The iron precipitate obtained in step (2) is gradually added to an iron precipitation solution containing 50 g / L triethylenetetramine, 150 g / L glutamic acid and 200 g / L ammonium sulfate. The pH value is adjusted to 8.0 with sulfuric acid, air is introduced, and the reaction is carried out at 70°C for 6 hours. Then the product is separated to obtain an iron concentrate product containing 61% iron and 0.2% zinc and an iron removal solution.

[0098] (4) The iron removal solution obtained in step (3) is electrolyzed using a 100 square centimeter graphite cathode to obtain metallic zinc with a purity of 98%.

[0099] (5) The lead-calcium slag obtained in step (1) is added to a leachate containing 0.5 g / L cystine, 250 g / L ethylenediaminetetraacetic acid, 200 g / L nickel sulfate and 100 g / L ammonium sulfate. The pH is adjusted to 9.5 with ammonia water. After reacting at 70°C for 2 hours, the residue and lead-calcium solution are separated to obtain tailings and lead-calcium solution.

[0100] (6) Evaporate the lead-calcium solution obtained in step (5) at 70°C, adjust the pH value to 9.0, and separate after reacting for 1 hour to obtain gypsum dihydrate with a purity of 99.5% and lead-containing solution.

[0101] (7) The lead-containing solution obtained in step (6) is introduced into carbon dioxide gas and reacted at 80°C for 2 hours. The solution is then separated to obtain a lead carbonate product with a purity of 98% and a circulating leachate. The circulating leachate is returned to step (5) for recycling.

[0102] Example 3

[0103] In this embodiment, the iron-containing raw material is a solution containing iron and zinc. In this case, steps (1)-(2) in Examples 1-2 can be omitted, and we can start directly from step (3):

[0104] (3) 50L of a mixed solution containing ferrous sulfate and zinc sulfate was gradually added to an iron precipitation solution containing 5g / L tetraethylenepentamine, 10g / L pyrophosphate, 260g / L phenylalanine and 200g / L sodium sulfate. The pH was adjusted to 9.0 with ammonia water, air was introduced, and the reaction was carried out at 80°C for 3 hours. The mixture was then separated to obtain an iron concentrate product containing 55% iron and 0.2% zinc, as well as an iron removal solution.

[0105] (4) The iron removal solution obtained in step (3) is adjusted to pH 7.0 with sulfuric acid, cooled to 30°C and kept for 1 hour to separate the zinc salt precipitate and solution. The solution can be recycled in this step or returned to step (3) for use.

[0106] (5) Dissolve the zinc salt precipitate obtained in step (4) with 100 g / L ammonia water and adjust the pH to 9.0. After filtration, adjust the pH of the solution to 7.0 with sulfuric acid. Then, pass carbon dioxide through to obtain zinc carbonate precipitate. Then separate to obtain zinc carbonate product and solution with a purity of 98%.

[0107] Example 4

[0108] This embodiment omits step (2) from Example 1 and directly uses the acid hydrolysate generated in step (1) as raw material for the following treatment:

[0109] (3) The acid hydrolysis solution generated in step (1) is gradually added to an iron precipitation solution containing 50 g / L triethylenetetramine, 150 g / L glutamic acid and 200 g / L ammonium sulfate. The pH value is adjusted to 8.0 with sulfuric acid, air is introduced, and the reaction is carried out at 70°C for 6 hours. Then the product is separated to obtain iron concentrate containing 62% iron and 0.1% zinc, as well as an iron removal solution.

[0110] (4) The iron removal solution obtained in step (3) is electrolyzed using a 100 square centimeter graphite cathode to obtain 99% pure metallic zinc.

[0111] (5) The lead-calcium slag obtained in step (1) is added to a leachate containing 0.5 g / L cystine, 250 g / L ethylenediaminetetraacetic acid, 200 g / L nickel sulfate and 100 g / L ammonium sulfate. The pH is adjusted to 9.5 with ammonia water. After reacting at 70°C for 2 hours, the residue and lead-calcium solution are separated to obtain tailings and lead-calcium solution.

[0112] (6) Evaporate the lead-calcium solution obtained in step (5) at 70°C, adjust the pH value to 9.0, and separate after reacting for 1 hour to obtain gypsum dihydrate with a purity of 99% and lead-containing solution.

[0113] (7) The lead-containing solution obtained in step (6) is introduced into carbon dioxide gas and reacted at 80°C for 2 hours. The solution is then separated to obtain a lead carbonate product with a purity of 99% and a circulating leachate. The circulating leachate is returned to step (5) for recycling.

[0114] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for the resource utilization of iron-containing raw materials, characterized in that, It includes: S1. Iron-containing raw materials are mixed with acid solutions to leach out metal element M from the iron-containing raw materials. Metal element M is a metal element that can combine with acid to form a soluble salt. After leaching, metal element M enters the acid hydrolysis solution to obtain acid hydrolysis solution and lead-calcium slag. Metal element M includes zinc, iron, manganese, magnesium, cadmium, nickel and copper. The reaction temperature is 0-110℃ and the pH value is -2 to 3. S2. The acid hydrolysate is subjected to one or more of the following methods: temperature-controlled crystallization, concentrated crystallization, and addition of inert salt, so that some of the zinc, iron, manganese, magnesium, cadmium, nickel, and copper elements in the acid hydrolysate crystallize into precipitates. After solid-liquid separation, iron-containing precipitate and crystallization mother liquor are obtained. The iron-containing precipitate is a sulfate, nitrate, chloride, perchlorate, or acetate containing zinc and iron elements; or the iron-containing precipitate is a double sulfate, double nitrate, chloride, perchlorate, or acetate containing zinc and iron alkali salt ions; the alkali salt ions are potassium, sodium, or ammonium ions; S3. Add the iron-containing precipitate or its aqueous solution to the iron precipitation solution, and introduce an oxidant to carry out an oxidation reaction. The iron element is converted into iron oxide powder. After separation, the zinc element is retained in the iron removal solution, and iron oxide powder and iron removal solution are obtained. The iron precipitation solution contains a zinc protectant, an iron morphology control agent and an inert salt. The reaction temperature is 0 to 110°C and the pH value is 5-13. The iron oxide powder is one or a combination of two or more of iron hydroxide, iron oxide, iron(III) oxide, and hydrated iron oxide; The oxidant is one or a combination of two or more of air, oxygen, hydrogen peroxide, potassium permanganate, manganese dioxide, and lead dioxide; the iron morphology control agent is capable of forming a weakly bound complex with ferric ions, and the concentration of the formed iron complex ions in the precipitating solution is less than 1*10. -5 A complexing agent of mol / L; the zinc protectant is one or a combination of two or more of the following: ethylenediamine, propylenediamine, hydroxyethylethylenediaminetriacetic acid, hydroxyethylidene diphosphate, aminotrimethylidene phosphate, diethylenetriaminepentamethylidene phosphate, tripolyphosphate, pyrophosphate, ethylenediaminetetraacetic acid, propylenediaminediacetic acid, ethylenediaminediacetic acid, ethylene glycol diethyl ether diaminetetraacetic acid, diethyl ether diaminetetraacetic acid, propylenediaminetetraacetic acid, hydroxyethylethylenediaminetriacetic acid, 2-aminobenzoic acid-N,N-diacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraaminehexaacetic acid, cyclohexanediaminetetraacetic acid, diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, sodium catechol-3,5-disulfonate, xylenol orange, and catechol purple; S4. Remove zinc from the iron removal solution generated in S3 by zinc salt precipitation or electrolysis; The electrolysis method involves passing direct current into the iron removal solution, which produces metallic zinc at the cathode. The zinc salt precipitation method is as follows: by adjusting the pH and / or temperature of the iron removal solution, the zinc in the iron removal solution is converted into zinc salt precipitate to obtain a zinc removal solution; the reaction temperature is 0 to 110℃ and the pH value is 4 to 12. S5. Dissolve the zinc salt precipitate in a circulating carbonization solution containing zinc solvent, control the pH value between 6.0 and 12.0, and then filter to remove impurities to obtain a purified zinc solution; adjust the pH value of the purified zinc solution to 5.0-11.0, and perform carbonization treatment to convert zinc into zinc carbonate precipitate and circulating carbonization solution. The circulating carbonization solution is recycled in this step.

2. The method for resource utilization of iron-containing raw materials according to claim 1, characterized in that, When the iron-containing raw material contains lead-calcium compounds, the processing method further includes steps S6-S8, as follows: S6. The lead-calcium slag produced in S1 is mixed and reacted with a leachate containing lead-enhancing solvent, calcium solvent, calcium co-solvent and inert salt to dissolve the lead and calcium elements in the lead-calcium slag. After separation, tailings and lead-calcium solution are obtained. The reaction temperature is 0 to 110℃ and the pH value is 7 to 13. The lead-enhancing solvent is a sulfur-containing complexing agent with strong complexing ability for lead ions; the lead-enhancing solvent is one or a combination of two or more of cysteine, cystine, mercaptopropionic acid, mercaptopropanol, mercaptoethanol, mercaptomethionine, and methimazole, and the amount added to the reaction system is 0.01-500 g / L. S7. Adjust the pH of the lead-calcium solution produced in S6 to 6-12, so that the calcium in the solution is separated in the form of calcium sulfate, and gypsum precipitate and lead-containing solution are obtained. Gypsum precipitate is one or more of calcium sulfate dihydrate, calcium sulfate hemihydrate, and anhydrous calcium sulfate; S8. A carbon source is introduced into the lead-containing solution produced in S7 to convert the lead into lead carbonate precipitate. After separation, lead carbonate and circulating leachate are obtained. The circulating leachate is returned to S6 as leachate. The carbon source is one or a combination of two or more of carbon dioxide, sodium carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, potassium carbonate, and potassium bicarbonate, and the amount added to the reaction system is 0.01-500 g / L.

3. The method for resource utilization of iron-containing raw materials according to claim 1, characterized in that, In S1, the acid solution is one or a combination of two or more of the following: sulfuric acid solution, nitric acid solution, sulfurous acid solution, perchloric acid solution, and hydrochloric acid solution. The iron-containing raw material is a waste residue containing zinc and iron elements. The waste residue includes one or more of the following: iron-containing neutralization slag, iron alum slag, zinc leaching slag, secondary zinc oxide, steelmaking fly ash, and zinc-containing furnace ash generated during lead / zinc / copper smelting.

4. The method for resource utilization of iron-containing raw materials according to claim 1, characterized in that, In S1, an inert salt and a catalyst are added to the acid solution; the catalyst is one or a combination of two or more of the following: cobalt, manganese sulfate, nitrate, chloride, perchlorate, acetate, and carbonate, and the amount added to the reaction system is 0.01-500 g / L; the inert salt is one or a combination of two or more of the following: potassium / sodium / ammonium / ferric / ferrous / zinc sulfate, nitrate, chloride, perchlorate, acetate, and carbonate, and the amount added to the reaction system is 0.01-500 g / L.

5. The method for resource recovery of iron-containing raw materials according to claim 1, characterized in that, In S2, the crystallization temperature is -30 to 90°C; the inert salt is one or more of potassium / sodium / ammonium sulfates, nitrates, chlorides, perchlorates, acetates, and carbonates, and the amount added to the reaction system is 0.01-500 g / L.

6. The method for resource utilization of iron-containing raw materials according to claim 1, characterized in that... In S3, the amount of zinc protective agent added to the reaction system is 0.01-500 g / L; The iron morphology control agent is one or a combination of two or more of the following: glutamic acid, valine, histidine, aspartic acid, leucine, isoleucine, alanine, proline, serine, phenylalanine, arginine, threonine, glycine, lysine, asparagine, glutamine, methionine, ornithine, taurine, citrulline, sarcosine, acetic acid, phthalic acid, and nicotinic acid, and the amount added to the reaction system is 0.01-500 g / L. The inert salt is one or a combination of two or more of the following: potassium / sodium / ammonium sulfates, nitrates, chlorides, perchlorates, acetates, and carbonates, and the amount added to the reaction system is 0.01-500 g / L.

7. The method for resource utilization of iron-containing raw materials according to claim 1, characterized in that, In S4, the zinc salt precipitate is a zinc-containing sulfate, nitrate, chloride, perchlorate, or acetate; or, The zinc salt precipitate is a sulfate double salt, nitrate double salt, chloride, perchloric acid double salt, or acetic acid double salt containing zinc and potassium / sodium / ammonium ions; In S5, the reaction temperature is between 0 and 110°C; the zinc solvent is one or a combination of two or more of ammonia, ethylamine, propylamine, imidazole, and ethylenediamine, and the amount added to the reaction system is 0.01-500 g / L.

8. The method for resource utilization of iron-containing raw materials according to claim 2, characterized in that... In S6, the calcium solvent is one or a combination of two or more of the following: hydroxyethyl ethylenediamine triacetic acid, hydroxyethylidene diphosphate, aminotrimethylidene phosphate, diethylenetriaminepentamethylidene phosphate, tripolyphosphate, pyrophosphate, ethylenediaminetetraacetic acid, propylenediamine diacetic acid, ethylenediamine diacetic acid, diethyl ether diaminetetraacetic acid, diethyl ether diaminetetraacetic acid, propylenediaminetetraacetic acid, hydroxyethyl ethylenediamine triacetic acid, 2-aminobenzoic acid-N,N-diacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraaminehexaacetic acid, cyclohexanediaminetetraacetic acid, and aminotriacetic acid; and the amount added to the reaction system is 0.01-500 g / L. The calcium co-solvent is one or a combination of two or more of the sulfates, chlorides, nitrates, and perchlorates of sodium, potassium, ammonium, magnesium, calcium, zinc, manganese, nickel, copper, cadmium, and lead ions, and the amount added to the reaction system is 0.01-500 g / L; the inert salt is one or a combination of two or more of the sulfates, nitrates, chlorides, perchlorates, acetates, and carbonates of potassium, sodium, ammonium, calcium, and magnesium, and the amount added to the reaction system is 0.01-500 g / L.

9. The method for resource utilization of iron-containing raw materials according to claim 2, characterized in that, The methods for adjusting pH in S1, S3, S4, S5, and S6 are: using organic bases, inorganic bases, organic acids, or inorganic acids to control the pH value of the solution; The organic base is one or more of methylamine, ethylamine, ethylenediamine, propylenediamine, and propylamine; the inorganic base is one or more of ammonia, potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, ammonium carbonate, calcium oxide, and calcium hydroxide; the organic acid is one or more of formic acid, acetic acid, oxalic acid, propionic acid, and citric acid; and the inorganic acid is one or more of sulfuric acid, hydrochloric acid, nitric acid, perchloric acid, and phosphoric acid. In step S7, the pH value of the solution is adjusted by evaporating alkaline gas to cause calcium to precipitate in the form of gypsum; the alkaline gas is ammonia, monoethanolamine, ethylenediamine, ethylamine or methylamine, and the alkaline gas generated by evaporation is directly recycled or converted back into alkali through condensation absorption for pH adjustment in S1, S3, S4, S5 and S6.

10. The method for resource utilization of iron-containing raw materials according to claim 1, characterized in that, When the iron-containing raw material in S1 is a solution containing iron and zinc, the acid leaching in step S1 and the crystallization precipitation in step S2 are omitted, and the iron-containing solution is directly used as the starting material for step S3, and the processes in steps S3-S5 are performed; or Omit step S2, that is, use the acid hydrolysate generated in S1 as the starting material for step S3, and process it according to steps S3-S5; or The crystallization mother liquor generated in step S2 is then used as the starting material for step S3 and processed according to steps S3-S5.

Images