Treatment method of electrolytic manganese slag

Abstract

The present invention provides a method for treating electrolytic manganese slag. The method comprises the following steps: sealing and stirring the electrolytic manganese slag and a modifier, and vacuuming to obtain modified manganese slag and a first flue gas, wherein the first flue gas is used to prepare an ammonia solution; mixing the modified manganese slag with a flux for oxidation smelting to obtain a first slag and a second flue gas, wherein the second flue gas is used to prepare concentrated sulfuric acid; mixing the first slag with a reducing agent and a regulator for reduction smelting to obtain a second slag, a third flue gas and a reduced metal liquid, adding a desulfurization and phosphorus agent to the reduced metal liquid for desulfurization and phosphorus removal to obtain a desulfurized phosphorus metal liquid; quenching and solidifying the second slag to obtain glass slag, and mixing the glass slag with an activator for grinding to obtain active micropowder. The present invention can synergistically treat a variety of sulfur-containing multi-metal solid wastes in electrolytic manganese slag, fully recover ammonia, sulfur and valuable metal resources in manganese slag, and realize the comprehensive utilization of all solid wastes in the whole process, with great social and economic benefits.

Description

Technical Field

[0001] The invention relates to the technical field of industrial metal waste slag treatment, and in particular to a method for treating electrolytic manganese slag. Background Art

[0002] Electrolytic manganese slag is an industrial waste residue obtained by leaching the metal elements in manganese ore with sulfuric acid solution and filtering it. The water content is generally about 30%. Electrolytic manganese slag is a black solid waste composed of fine particles, which is acidic or weakly acidic, with a density of 2~3g / cm 3 If it is discharged directly, the water content will be higher due to the storage of rainwater, and it will be in a muddy state. After air drying, the particles will agglomerate and have mud plasticity. Depending on the ore grade and production process, the amount of manganese slag discharged for every ton of electrolytic manganese metal produced is an average of 8 to 10 tons. Therefore, the output of electrolytic manganese slag is large and occupies a large amount of land resources. Moreover, electrolytic manganese slag contains toxic and harmful substances such as soluble sulfates, heavy metals, and residual acids, which have a serious ecological impact on the local and surrounding soil and groundwater. Therefore, it is urgent to dispose of electrolytic manganese slag harmlessly and as a resource.

[0003] Affected by the electrolytic manganese metal process requirements, electrolytic manganese slag often contains ammonia, Ca, Al, Si, Mn, S, Fe, and Cr, Ni, Zn, Cu, etc., wherein the non-ferrous metal content is low and the recovery value is small. However, Mn and Fe content are higher in some manganese slags, which have recovery value. In addition, due to the presence of more sulfates in electrolytic manganese slag, such as calcium sulfate, manganese sulfate, ferric sulfate, etc., the main approach to its treatment and resource utilization is currently to replace gypsum as a raw material for building materials such as cement retarder, cement concrete, and wall materials. For example, patent of invention CN 110467365 A uses electrolytic manganese slag to prepare cement, CN 108585721 A uses electrolytic manganese slag and steel slag tailings to produce autoclaved aerated blocks, and CN 109482624 A uses electrolytic manganese slag to produce sintered lightweight aggregate, etc.

[0004] In addition, electrolytic manganese slag has a high sulfur content, and industrial sulfuric acid can be prepared by high-temperature calcination or roasting, such as patents CN 105217580 B, CN 110482612 A, etc., which realizes the recycling of sulfur in manganese slag, and the product has high added value. Moreover, manganese slag contains more iron and manganese elements, and metal oxides can be separated by roasting and magnetic separation processes, such as patent CN 106755950 B. Manganese iron alloy can be prepared by adding manganese ore and using electric furnace smelting, such as patent CN105624438 B, which realizes the recovery of valuable metal elements in electrolytic manganese slag.

[0005] However, existing technologies for treating electrolytic manganese slag are mostly focused on single-field applications such as the use of electrolytic manganese slag as building materials or the extraction of valuable metal elements. These technologies are easily restricted by factors such as the regionality of the industry, the lack of cross-disciplinary technical connectivity, and insufficient development of core process equipment. They are unable to maximize the value of the electrolytic manganese slag, and the products are single, with low added value, insufficient applicability, and high market risks.

[0006] Electrolytic manganese slag contains high levels of sulfate and residual acid. Large-scale use will reduce the cement setting rate and affect cement performance. The original manganese slag and calcined manganese slag have low hydration activity due to incomplete sulfur decomposition and high sulfur content, which limits the scope of application and dosage, and the product has low added value, and has not been widely promoted and applied. In addition, electrolytic manganese slag contains harmful substances such as ammonium sulfate and heavy metal ions. If it is directly used in building materials production, it will not only affect the production process, but also the product quality will be poor, and it is prone to frost and cracking. Moreover, these heavy metals will enter the water environment with rainwater, threatening ecological safety. Summary of the invention

[0007] The main purpose of the present invention is to provide a method for treating electrolytic manganese slag to solve the problems of single product, low added value, insufficient applicability and serious environmental pollution in the prior art when treating electrolytic manganese slag.

[0008] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided a method for treating electrolytic manganese slag, comprising the following steps: step S1, mixing the electrolytic manganese slag with a modifier, performing sealed stirring and negative pressure suction, to obtain modified manganese slag and a first flue gas, the first flue gas is used to prepare an ammonia solution; step S2, mixing the modified manganese slag with a flux for oxidative smelting, to obtain a first slag and a second flue gas, the second flue gas is used to prepare concentrated sulfuric acid; step S3, mixing the first slag with a reducing agent and a regulating agent for reduction smelting, to obtain a second slag, a third flue gas and a reduced metal liquid, adding a desulfurization and phosphorus agent to the reduced metal liquid for desulfurization and phosphorus, to obtain a desulfurized phosphorus metal liquid; step S4, quenching and solidifying the second slag to obtain glass slag, mixing the glass slag with an activator for pulverization, to obtain active micropowder.

[0009] Furthermore, in step S1, the first flue gas is subjected to ammonia solution production to obtain ammonia production wastewater; the ammonia production wastewater is subjected to a first wastewater treatment to obtain a first sludge and / or a first sludge, which is then sent to an oxidation smelting step.

[0010] Furthermore, the electrolytic manganese slag comprises, by weight percentage, 8-27% calcium oxide, 5-13% manganese oxide, 2-11% iron oxide, 15-52% sulfur trioxide, 0.5-2% ammonia water, 15-28% silicon oxide and residual impurities; and / or the modifier comprises one or more of quicklime, calcined dolomite, slaked lime, steel slag powder and desulfurized gypsum; and / or by weight percentage, the modifier is 5-20% of the electrolytic manganese slag.

[0011] Furthermore, in step S2, the second flue gas is subjected to the first waste heat power generation, and dust removal and concentrated sulfuric acid preparation are performed in sequence to obtain acid-making wastewater; the acid-making wastewater is subjected to the second wastewater treatment to obtain second sludge and / or second slag, which are then sent to the oxidation smelting step.

[0012] Further, the flux comprises 40-90% CaO by weight; and / or the flux comprises one or more of limestone, dolomite, industrial by-product gypsum and steel slag; and / or the flux is 20-50% of the electrolytic manganese slag by weight.

[0013] Furthermore, the oxidation smelting is carried out in a smelting furnace, which is a side-blown furnace, a bottom-blown furnace, a top-blown furnace or an induction furnace; and / or the temperature of the oxidation smelting is 1220~1360℃.

[0014] Furthermore, step S3 also includes the following steps: subjecting the third flue gas to secondary combustion and then to second waste heat power generation, the power generation tail gas enters the flue gas chemical process or grinding step, and is finally discharged after desulfurization treatment.

[0015] Furthermore, the desulfurized phosphorus molten metal is cast into ingots to obtain metal ingots; and / or the reduced metal liquid is desulfurized to obtain desulfurized phosphorus slag; the desulfurized phosphorus slag is sent to an oxidation smelting step; and / or the desulfurized phosphorus agent includes one or more of quicklime, calcium carbide, calcined magnesite, calcined dolomite, metallic magnesium and soda.

[0016] Furthermore, the carbon content in the reducing agent is greater than 30% by weight; and / or the reducing agent includes one or more of lump coal, coke, semi-coke, biochar and waste graphite electrodes; and / or the reducing agent is 10-20% of the electrolytic manganese slag by weight.

[0017] Furthermore, the adjusting agent is 2-10% of the electrolytic manganese slag by weight; and / or the adjusting agent is manganese-containing or iron-containing natural minerals and / or solid waste.

[0018] Furthermore, the reduction smelting is carried out in a metallurgical furnace, which is an electrode furnace, an arc furnace, a plasma furnace, a side-blown furnace, a bottom-blown furnace or an induction furnace; and / or the temperature of the reduction smelting is 1400~1650℃.

[0019] Furthermore, step S4 also includes the step of preparing one or more of cement, concrete and prefabricated parts using the active micropowder as raw material.

[0020] Furthermore, the rapid cooling and solidification method is water quenching and / or air quenching; and / or the activator includes one or more of fly ash, quicklime, gypsum, slag, steel slag, clinker, cement, sodium silicate and sodium hydroxide; and / or the activator is 0.2-20% of the glass slag by weight; and / or the grinding equipment is one or more of a ball mill, a vertical mill and a roller mill.

[0021] Furthermore, the desulfurized phosphorus metal liquid is pig iron liquid, manganese-containing pig iron liquid or manganese-iron alloy liquid.

[0022] Furthermore, the specific surface area of ​​the active micropowder is ≥350 m 2 / kg, 7-day activity index ≥70%, 28-day activity index ≥95%.

[0023] By applying the technical solution of the present invention, ammonia, sulfur and valuable metal resources in manganese slag can be economically and fully recovered, and ammonia solution, concentrated sulfuric acid and metal liquid can be prepared. The tailings can be used to prepare active micropowders, and further can be used to prepare building materials. The treatment method of the present invention can synergistically treat a variety of sulfur-containing multi-metal solid wastes and realize the comprehensive utilization of all solid wastes in the whole process. The method of the present invention can effectively avoid the acidification and heavy metal pollution of soil and water bodies caused by the storage of electrolytic manganese slag, as well as the occurrence of environmental safety problems such as land occupation, safety hazards, and ecological damage, and has huge social and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1 A schematic diagram of a treatment process of electrolytic manganese slag according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0026] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0027] Terminology explanation:

[0028] Active micropowder: A type of powder material that can form various hydration products and harden through hydration reaction in alkaline aqueous solution, that is, a powder material with potential hydration activity.

[0029] Clinker: A semi-finished cement product formed by calcining cement raw materials such as limestone and clay at high temperature until they are partially or completely melted and then cooled.

[0030] Activity Index: refers to the ratio of the compressive strength of the test specimen measured by standard testing methods to the compressive strength of the comparison specimen.

[0031] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged under appropriate circumstances to describe the embodiments of the present invention.

[0032] As described in the background technology of the present invention, the prior art has the problems of single product, low added value, insufficient applicability and serious environmental pollution when treating electrolytic manganese slag. In order to solve the above problems, in a typical embodiment of the present invention, a method for treating electrolytic manganese slag is provided, comprising the following steps: step S1, mixing the electrolytic manganese slag with a modifier, performing sealed stirring and negative pressure suction, obtaining modified manganese slag and a first flue gas, the first flue gas is used to prepare an ammonia solution; step S2, mixing the modified manganese slag with a flux for oxidation smelting, obtaining a first slag and a second flue gas, the second flue gas is used to prepare concentrated sulfuric acid; step S3, mixing the first slag with a reducing agent and a regulator for reduction smelting, obtaining a second slag, a third flue gas and a reduced metal liquid, adding a desulfurization and phosphorus agent to the reduced metal liquid for desulfurization and phosphorus, and obtaining a desulfurization and phosphorus metal liquid; step S4, quenching and solidifying the second slag to obtain glass slag, mixing the glass slag with an activator for grinding, and obtaining active micropowder.

[0033] The electrolytic manganese slag of the present invention refers to the electrolytic manganese slag that has been subjected to filter pressing treatment. The present invention firstly seals and stirs the electrolytic manganese slag with the modifier, during which the active components in the modifier react with the free water in the electrolytic manganese slag to produce OH - ions and release heat, OH - Same as NH in electrolytic manganese slag 4 + The ammonia solution is converted into ammonia gas and water vapor under the influence of heat. Negative pressure suction is carried out under sealed stirring state, which is conducive to the conversion of ammonia solution into ammonia gas and overflow. Various gases generated in this process are collected to obtain ammonia-containing flue gas (first flue gas). The ammonia-containing flue gas is used as a raw material to prepare ammonia solution. The ammonia solution can be sold as a commodity or used by electrolytic manganese enterprises.

[0034] Secondly, the modified manganese slag is mixed with flux for oxidation smelting. During this process, the modified manganese slag and flux are rapidly heated and melted, and the sulfur-containing compounds in the manganese slag are rapidly decomposed or oxidized into gases such as sulfur dioxide and sulfur trioxide. The various gases generated in the oxidation and melting process are combined to obtain sulfur-containing flue gas (second flue gas). The sulfur-containing flue gas is used as a raw material to prepare concentrated sulfuric acid, which can be sold as a commodity or used by electrolytic manganese enterprises.

[0035] Then, the first slag is mixed with a reducing agent and a regulating agent for reduction smelting. Under the action of the reducing agent, the metal oxides in the first slag are reduced to reduced metal liquid. A desulfurization and phosphorus agent is added to the reduced metal liquid to remove the sulfur and phosphorus elements in the metal liquid to obtain a desulfurized and phosphorus-depleted metal liquid, which can be sold to smelting or casting companies. Among them, the regulating agent is used to adjust the slag shape, supplement the sulfur content of the flue gas, and increase the metal output. At the same time, the flue gas (third flue gas) generated during the reduction smelting process is collected.

[0036] Finally, the second slag is rapidly cooled and solidified to make it amorphous to obtain glass slag, which is then mixed with an activator and ground into powder. The degree of dissociation of the aluminosilicate network in the glass slag is improved, and the active Si and Al contents are thereby increased, thereby obtaining active micropowder with high potential hydration activity and low residual heavy metals.

[0037] The method of the present invention fully utilizes the components of the electrolytic manganese slag to simultaneously prepare ammonia solution, concentrated sulfuric acid, metal liquid and active micropowder by subjecting the electrolytic manganese slag to "negative pressure sealing self-heating deammoniation - oxidation smelting rapid desulfurization - reduction smelting metal extraction - tailings vitrification composite excitation". The product variety is diverse, the value is high, the application is in many fields, the market risk is small, and there are no environmental safety issues such as acidification of soil and water bodies and heavy metal pollution caused by the storage of electrolytic manganese slag, as well as land occupation, safety hazards, ecological damage, etc. The method can realize the resource utilization and harmless treatment of the electrolytic manganese slag, and has huge social and economic benefits.

[0038] In a preferred embodiment, in step S1, the first flue gas is subjected to ammonia aqueous solution to obtain ammonia wastewater; the ammonia wastewater is subjected to a first wastewater treatment to obtain a first sludge and / or a first sludge, which is then sent to an oxidation smelting step. When the first flue gas is used to produce an ammonia aqueous solution, a conventional chemical ammonia production process can be used. Under the above conditions, the wastewater generated in the ammonia production process is treated, and the obtained sludge or sludge is sent to the oxidation smelting step for recycling, so that the solid waste in the ammonia production process can be more fully recycled.

[0039] In a preferred embodiment, the electrolytic manganese slag comprises, by weight percentage, 8-27% calcium oxide, 5-13% manganese oxide, 2-11% iron oxide, 15-52% sulfur trioxide, 0.5-2% ammonia water, 15-28% silicon oxide and residual impurities; and / or the modifier comprises one or more of quicklime, calcined dolomite, slaked lime, steel slag powder and desulfurized gypsum; and / or the modifier is 5-20% of the electrolytic manganese slag by weight percentage.

[0040] Under the above conditions, the electrolytic manganese slag can react more fully with the modifier, which is more conducive to fully recovering the ammonia in the electrolytic manganese slag. - The content is insufficient and cannot be compared with NH 4- A full reaction may affect the recovery of ammonia and the concentration of the prepared ammonia solution, resulting in ammonia loss, and causing problems such as ammonia escape and environmental impact in subsequent treatment processes. If the amount of modifier used is too much, the modifier will be excessive, which will lead to an increase in the melting temperature of the slag in the subsequent process and an increase in the slag viscosity, thereby increasing the temperature required for subsequent smelting and increasing the processing cost.

[0041] In order to make more effective use of the waste heat of the desulfurized flue gas and further reduce energy consumption, in a preferred embodiment, in step S2, the second flue gas is subjected to the first waste heat power generation, and after dust removal and concentrated sulfuric acid preparation, acid-making wastewater is obtained. The dust removal and purification and concentrated sulfuric acid preparation steps are carried out in the conventional chemical acid-making process. In order to make more effective use of the solid waste in the acid-making process, in a preferred embodiment, the acid-making wastewater is subjected to the second sewage treatment to obtain the second sludge and / or the second slag, which are then sent to the oxidation smelting step. The second sludge and / or the second slag can be used as return material. It should be noted that "return material" in this application refers to: a by-product that can continue to be used as a front-end process raw material in the process production process. This term is commonly understood by those skilled in the art and will not be repeated here.

[0042] In order to make the modified manganese slag oxidized and smelted more quickly, in a preferred embodiment, the flux includes 40-90% CaO by weight; and / or the flux includes one or more of limestone, dolomite, industrial by-product gypsum and steel slag; and / or by weight, the flux is 20-50% of the electrolytic manganese slag. The industrial by-product gypsum can be derived from engineering gypsum solid waste residues such as flue gas desulfurization gypsum, fluorite, phosphogypsum and titanium gypsum. The melting point of the modified manganese slag is about 1100-1250°C, and the decomposition temperature of the sulfur-containing compounds in the modified manganese slag is about 600-1150°C. In order to facilitate the melting of the modified manganese slag and the decomposition of the sulfur-containing compounds in the modified manganese slag, in a preferred embodiment, the oxidative smelting is carried out in a smelting furnace, which is a side-blown furnace, a bottom-blown furnace, a top-blown furnace or an induction furnace; and / or the temperature of the oxidative smelting is 1220-1360°C; and / or the atmosphere of the oxidative smelting is maintained at O 2 The volume content is 0.3~4%.

[0043] Under the above conditions, the modified manganese slag can melt and flow more quickly, and the sulfur-containing compounds can be decomposed into sulfur dioxide, sulfur trioxide and other gases more quickly, so that sulfur-containing flue gas can be obtained more quickly in a short time. If the oxidation smelting temperature is too low, the fluidity of the slag is poor. If the oxidation smelting temperature is too high, it will consume too much energy and increase costs.

[0044] In order to more fully recycle the waste heat of flue gas, in a preferred embodiment, step S3 also includes the following steps: the third flue gas is subjected to secondary combustion for second waste heat power generation, the power generation tail gas enters the flue gas chemical process or grinding step, and finally is discharged after desulfurization treatment. In addition, the third flue gas can also be subjected to secondary combustion and then waste heat power generation to make more full use of the energy of the third flue gas. Among them, the flue gas chemical process refers to the flue gas acid production, including conversion and absorption processes.

[0045] For the purpose of facilitating the transportation and external sale of metal, in a preferred embodiment, the desulfurized phosphorus metal liquid is cast into ingots to obtain metal ingots. In order to facilitate the recycling of the solid slag produced in the desulfurized phosphorus process, in a preferred embodiment, the reduced metal liquid is desulfurized to obtain desulfurized phosphorus slag; the desulfurized phosphorus slag is sent to the oxidation smelting step. Under the above conditions, the sludge or slag obtained by sewage treatment and the desulfurized phosphorus slag are returned to the smelting furnace, and are quickly heated to a melt at a high temperature, and can be heat-conducted to the modified manganese slag, which is more conducive to the rapid melting of the modified manganese slag and the decomposition of sulfur-containing oxides. While the solid slag is recycled, the heat conduction effect is better exerted. In order to further reduce the impurity elements such as S and P in the metal liquid, in a preferred embodiment, the desulfurized phosphorus agent includes one or more of quicklime, calcium carbide, calcined magnesite, calcined dolomite, metallic magnesium and soda. Under the above conditions, the impurity S and P elements in the desulfurized phosphorus metal liquid can be further reduced to below the corresponding standard range.

[0046] In order to further improve the degree of reduction of metal oxides in slag and more fully recycle valuable metals, in a preferred embodiment, the carbon content in the reducing agent is greater than 30% by weight; and / or the reducing agent includes one or more of lump coal, coke, blue charcoal, biomass charcoal and waste graphite electrodes; and / or the reducing agent is 10-20% of the electrolytic manganese slag by weight. The adjusting agent is 2-10% of the electrolytic manganese slag by weight, and / or the adjusting agent is a manganese- or iron-containing natural mineral and / or solid waste, preferably manganese ore and / or iron ore. Under the above conditions, the metal yield can be more fully increased.

[0047] In order to more fully carry out the reduction and melting reaction, thereby improving the recovery rate of valuable metals, in a preferred embodiment, the reduction smelting is carried out in a metallurgical furnace, which is an electrode furnace, an arc furnace, a plasma furnace, a side-blown furnace, a bottom-blown furnace or an induction furnace; and / or the temperature of the reduction smelting is 1400-1650° C. If the reduction smelting temperature is lower than 1400° C., the metal reduction effect is poor and the metal recovery rate is low. If the temperature is higher than 1650° C., the energy consumption is high, the damage to the reduction smelting furnace structure is large, and the cost is high.

[0048] In a preferred embodiment, step S4 further includes the step of preparing one or more of cement, concrete and prefabricated parts using the active micropowder as raw material. The active micropowder of the present invention has harmful substances such as heavy metal ions removed, so it can be directly used in large quantities in the production of building materials, with high product quality, and is not prone to problems such as frost cracking and environmental pollution. It can more fully increase the amount of solid slag used in the field of building materials, thereby further realizing the comprehensive utilization of electrolytic manganese slag.

[0049] In order to obtain amorphous glass slag more smoothly and efficiently, in a preferred embodiment, the rapid cooling and solidification method is water quenching and / or wind quenching. Industrial production usually uses direct water flushing or compressed air blowing, and the amount of coolant used is relatively abundant. In a preferred embodiment, the cooling rate of water quenching is 180~220℃ / s; and / or the cooling rate of wind quenching is 87~95℃ / s. In order to further improve the stimulating effect of the activator on glass slag, so as to be more conducive to obtaining high-quality active micropowder, in a preferred embodiment, the activator includes one or more of fly ash, quicklime, gypsum, slag, steel slag, clinker, cement, sodium silicate and sodium hydroxide; and / or the activator is 0.2~20% of the glass slag by weight percentage. In order to obtain active micropowders with smaller specific surface area and greater activity, thereby further improving the utilization value of active micropowders in the field of building materials and reducing the difficulty of utilization, in a preferred embodiment, the grinding equipment is one or more of a ball mill, a vertical mill and a roller mill.

[0050] In order to further improve the product value, in a preferred embodiment, the desulfurized phosphorus metal liquid is pig iron liquid, manganese-containing pig iron liquid or manganese-iron alloy liquid. In a preferred embodiment, according to the above preparation method of the present invention, the specific surface area of ​​the obtained active micropowder is ≥350 m 2 / kg, 7-day activity index ≥70%, 28-day activity index ≥95%.

[0051] Typically but not limiting, by weight percentage, the modifier is 5%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20% of the electrolytic manganese slag or a range consisting of any two of them; the flux is 20%, 25%, 30%, 35%, 40%, 45%, 50% of the electrolytic manganese slag or a range consisting of any two of them; the reducing agent is 10%, 12%, 14%, 15%, 16%, 18%, 20% of the electrolytic manganese slag or a range consisting of any two of them; the adjusting agent is 2%, 4%, 6%, 8%, 10% of the electrolytic manganese slag or a range consisting of any two of them; by weight percentage, the activator is 0.2%, 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20% of the glass slag or a range consisting of any two of them.

[0052] Typically, but not limiting, the temperature of the oxidation smelting is 1220°C, 1250°C, 1300°C, 1350°C, 1360°C or a range consisting of any two of these values.

[0053] Typically, but not limiting, the temperature of the reduction smelting is 1400°C, 1450°C, 1500°C, 1550°C, 1600°C, 1650°C or a range consisting of any two of them.

[0054] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0055] Example 1

[0056] The schematic diagram of the treatment process of electrolytic manganese slag is shown in Figure 1 .

[0057] The composition of electrolytic manganese slag is: 14% calcium oxide, 9% manganese oxide, 8% iron oxide, 32% sulfur trioxide, 1.5% ammonia water, 22% silicon oxide and the remaining impurities.

[0058] By weight percentage, the modifier (slaked lime) is 12% of the electrolytic manganese slag, the flux (limestone) is 35% of the electrolytic manganese slag, the reducing agent (lump coal with a carbon content of about 80%) is 15% of the electrolytic manganese slag, and the adjusting agent (iron ore) is 6% of the electrolytic manganese slag; by weight percentage, the activator (fly ash) is 12% of the glass slag.

[0059] Step S1, stirring the electrolytic manganese slag and the modifier in a sealed mixer, and then loading the stirred mixture into a negative pressure silo, collecting the ammonia generated during the suction process to obtain ammonia-containing flue gas, the main components of which include NH 3 , H 2 O、N 2 , after the ammonia-containing flue gas is sent to the chemical ammonia production process for treatment, an ammonia solution with a mass concentration of 18% and ammonia production wastewater are obtained, the ammonia solution is sold or returned to the electrolytic manganese enterprise for reuse, the ammonia production wastewater is treated, the obtained water is sent to the chemical ammonia production process for recycling, and the obtained sludge or slag is sent to the oxidation smelting furnace for use as a melt material;

[0060] Step S2: The modified manganese slag and flux are fed into a side-blown furnace filled with high-temperature melt. The smelting temperature in the furnace is controlled to be 1300°C. Combustion-supporting air and fuel are blown into the furnace for combustion. The oxygen volume content in the furnace is set to 3%. The SO generated during the process is collected. 2 、SO 3The sulfur-containing gas is discharged from the furnace, and after waste heat power generation and dust removal and purification treatment, it is sent to the chemical acid production process for treatment to obtain concentrated sulfuric acid with a concentration of 98% and acid production wastewater. The concentrated sulfuric acid is sold or used by electrolytic manganese enterprises. The acid production wastewater is treated, and the obtained water is sent to the chemical ammonia production process for recycling. The obtained sludge or slag is sent to the oxidation smelting furnace for use as melt material;

[0061] Step S3, adding the slag, reducing agent and adjusting agent produced by oxidation smelting into the electrode furnace, reducing and depleting the metal elements in the slag, controlling the smelting temperature in the furnace to 1500°C, discharging and collecting the generated reduced molten metal, adding a desulfurization and phosphorus agent into the reduced molten metal, obtaining desulfurized molten metal and desulfurized phosphorus slag, casting the desulfurized molten metal into metal ingots for sale, and returning the desulfurized phosphorus slag, which is mainly CaO, to the oxidation smelting furnace for use as a melt material; during the reduction smelting process, the molten metal containing CO, H 2 After secondary combustion, the waste heat of flue gas such as O is sent to power generation, and the remaining low-heat tail gas is used for flue gas chemical process and glass slag grinding process. Finally, the tail gas is discharged after desulfurization treatment;

[0062] Step S4, placing the molten tailings produced by the reduction smelting into a water quenching pool, using a water spray quenching method to cool the molten tailings at 1500°C to 500°C within 5 seconds, so that it is quenched and solidified to obtain glass slag; adding an activator to the glass slag, using a ball mill at 90°C for 2 hours to obtain a specific surface area of ​​420 m 2 / kg, the active micropowder has an activity index of 86% in 7 days and 102% in 28 days, and is sold to cement, concrete, prefabricated parts and other building materials companies.

[0063] Example 2

[0064] The only difference from Example 1 is:

[0065] By weight percentage, the modifier (calcined dolomite) is 5% of the electrolytic manganese slag, the flux (gypsum) is 50% of the electrolytic manganese slag, the reducing agent (coke with a carbon content of about 90%) is 10% of the electrolytic manganese slag, and the adjusting agent (manganese ore) is 2% of the electrolytic manganese slag; by weight percentage, the activator (fly ash) is 20% of the glass slag.

[0066] Example 3

[0067] The only difference from Example 1 is:

[0068] By weight percentage, the modifier (slaked lime) is 20% of the electrolytic manganese slag, the flux (dolomite, limestone) is 20% of the electrolytic manganese slag, the reducing agent (waste graphite electrode with a carbon content of about 98%) is 20% of the electrolytic manganese slag, and the adjusting agent (iron ore) is 10% of the electrolytic manganese slag; by weight percentage, the activator (sodium silicate) is 0.2% of the glass slag.

[0069] Example 4

[0070] The only difference from Example 1 is:

[0071] The temperature of oxidation smelting is 1220℃; the atmosphere of oxidation smelting contains O 2 The volume content is 4%; the smelting furnace is a bottom-blown furnace;

[0072] The temperature of reduction smelting is 1650℃; the metallurgical furnace is an electric arc furnace;

[0073] Step S4, putting the molten tailings produced by reduction smelting into an air cooler, using air rapid cooling to cool the 1650°C molten tailings to 700°C within 10 seconds, so that it is rapidly cooled and solidified to obtain glass slag; adding an activator to the glass slag, and using a ball mill to grind it at 90°C for 2 hours.

[0074] Example 5

[0075] The only difference from Example 1 is:

[0076] The temperature of oxidation smelting is 1360℃; the atmosphere of oxidation smelting contains O 2 The volume content is 0.3%; the smelting furnace is a top-blown furnace;

[0077] The temperature of reduction smelting is 1400℃; the metallurgical furnace is a plasma furnace;

[0078] Step S4, putting the molten tailings produced by reduction smelting into an air cooler, using air rapid cooling to cool the 1400°C molten tailings to 700°C within 8 seconds, so that it is rapidly cooled and solidified to obtain glass slag; adding an activator to the glass slag, and using a ball mill to grind it at 90°C for 2 hours.

[0079] The specific surface area, 7-day activity index and 28-day activity index of the active micropowder prepared in the above examples are shown in Table 1.

[0080] Test method:

[0081] Activity index test: refer to GB / T 18046-2017 for testing.

[0082] Table 1

[0083]

[0084] From the above, it can be seen that by adopting the method provided by the present invention, the components of the electrolytic manganese slag are fully utilized to prepare ammonia solution, concentrated sulfuric acid, metal liquid, and active micropowder by subjecting the electrolytic manganese slag to "negative pressure sealing self-thermal deamination - oxidation smelting rapid desulfurization - reduction smelting metal extraction - tailings vitrification composite excitation". The products are diverse in variety, high in value, applicable to many fields, and have low market risks. In addition, there are no environmental safety issues such as acidification of soil and water bodies and heavy metal pollution caused by the storage of electrolytic manganese slag, as well as land occupation, safety hazards, and ecological damage. The resource utilization and harmless treatment of electrolytic manganese slag can be achieved, and the social and economic benefits are huge.

[0085] In addition, it can be seen that when all process parameters are within the preferred range of the present invention, the obtained active micropowder and other products have higher value.

[0086] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for treating electrolytic manganese slag, characterized in that: The following steps are involved: Step S1, mixing electrolytic manganese slag and a modifier, stirring in a sealed manner, and suctioning under negative pressure to obtain modified manganese slag and a first flue gas, wherein the first flue gas is used to prepare an ammonia solution; Step S2, mixing the modified manganese slag with a flux for oxidative smelting to obtain a first molten slag and a second flue gas, wherein the second flue gas is used to produce concentrated sulfuric acid; Step S3, mixing the first slag with a reducing agent and a regulating agent for reduction smelting to obtain a second slag, a third flue gas and a reduced metal liquid, adding a desulfurization and phosphorus removal agent to the reduced metal liquid for desulfurization and phosphorus removal to obtain a desulfurized and phosphorus removal metal liquid; Step S4, rapidly cooling and solidifying the second molten slag to obtain glass slag, and mixing the glass slag with an activator and grinding them to obtain active micro powder; Wherein, the electrolytic manganese slag comprises, by weight percentage, 8-27% calcium oxide, 5-13% manganese oxide, 2-11% iron oxide, 15-52% sulfur trioxide, 0.5-2% ammonia water, 15-28% silicon oxide and the remainder impurities; The temperature of the oxidation smelting is 1220-1360°C, and the temperature of the reduction smelting is 1400-1650°C; The adjusting agent is 2-10% of the amount of the electrolytic manganese slag, and the adjusting agent is manganese-containing or iron-containing natural minerals and / or solid waste.

2. The processing method according to claim 1, characterized in that: In the step S1, the first flue gas is subjected to ammonia solution production to obtain ammonia production wastewater; the ammonia production wastewater is subjected to a first wastewater treatment to obtain a first sludge and / or a first sludge, which is then sent to the oxidation smelting step.

3. The processing method according to claim 1 or 2, characterized in that: The modifier includes one or more of quicklime, calcined dolomite, slaked lime, steel slag powder and desulfurized gypsum; and / or the modifier is 5-20% of the electrolytic manganese slag in terms of weight percentage.

4. The processing method according to claim 1 or 2, characterized in that: In the step S2, The second flue gas is subjected to first waste heat power generation, and dust removal and concentrated sulfuric acid preparation are performed in sequence to obtain acid-making wastewater; the acid-making wastewater is subjected to second wastewater treatment to obtain second sludge and / or second slag, which are then sent to the oxidation smelting step.

5. The processing method according to claim 1 or 2, characterized in that: The flux comprises 40-90% CaO by weight; and / or The flux comprises one or more of limestone, dolomite, industrial by-product gypsum and steel slag; and / or In terms of weight percentage, the flux is 20-50% of the electrolytic manganese slag.

6. The processing method according to claim 1 or 2, characterized in that: The oxidation smelting is carried out in a smelting furnace, which is a side-blown furnace, a bottom-blown furnace, a top-blown furnace or an induction furnace.

7. The processing method according to claim 1 or 2, characterized in that: The step S3 further comprises the following steps: The third flue gas is subjected to secondary combustion and then subjected to second waste heat power generation, and the power generation tail gas enters the flue gas chemical process or the grinding step, and is finally discharged after desulfurization treatment.

8. The processing method according to claim 1 or 2, characterized in that: The step S3 further comprises the following steps: Casting the desulfurized phosphorus molten metal into ingots to obtain metal ingots; and / or Desulfurizing the reduced metal liquid to obtain desulfurized phosphorus slag; feeding the desulfurized phosphorus slag into the oxidation smelting step; The desulfurization phosphorus agent includes one or more of quicklime, calcium carbide, calcined magnesite, calcined dolomite, metallic magnesium and soda.

9. The processing method according to claim 1 or 2, characterized in that: The carbon content of the reducing agent is greater than 30% by weight; and / or The reducing agent comprises one or more of lump coal, coke, blue charcoal, biomass charcoal and waste graphite electrodes; and / or In terms of weight percentage, the reducing agent accounts for 10-20% of the electrolytic manganese slag.

10. The processing method according to claim 1 or 2, characterized in that: The reduction smelting is carried out in a metallurgical furnace, which is an electrode furnace, an electric arc furnace, a plasma furnace, a side-blowing furnace, a bottom-blowing furnace or an induction furnace.

11. The processing method according to claim 1 or 2, characterized in that: The step S4 also includes the step of preparing one or more of cement, concrete and prefabricated parts using the active micropowder as raw material.

12. The processing method according to claim 1 or 2, characterized in that: The rapid cooling and solidification method is water quenching and / or air quenching; and / or The activator comprises one or more of fly ash, quicklime, gypsum, slag, steel slag, clinker, cement, sodium silicate and sodium hydroxide; and / or In terms of weight percentage, the activator is 0.2-20% of the glass slag; and / or The grinding equipment is one or more of a ball mill, a vertical mill and a roller mill.

13. The processing method according to claim 1 or 2, characterized in that: The desulfurized phosphorus metal liquid is pig iron liquid, manganese-containing pig iron liquid or manganese-iron alloy liquid.

14. The processing method according to claim 1 or 2, characterized in that: The specific surface area of ​​the active micropowder is ≥350 m 2 / kg, 7-day activity index ≥70%, 28-day activity index ≥95%.

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