Electrolytic metal manganese slag treatment method

Abstract

The invention relates to the technical field of metallurgy, in particular to an electrolytic manganese metal slag treatment method. Comprising the following steps that firstly, the electrolytic metal manganese slag is dried, and dried manganese slag and ammonia-containing wet flue gas are obtained; step 2 and / or step 3; the second step comprises the steps that the dried manganese slag is mixed with an activating agent and a reducing agent and then roasted, and first sulfur-containing flue gas and high-temperature roasted slag are obtained; crushing the high-temperature roasting slag to obtain active micro powder; the roasting temperature is 900 to 1050 DEG C; and the third step comprises the following steps: grinding and mixing the dried manganese slag and the coal-series solid waste, adding a pore-forming agent, granulating to obtain raw material balls, and sintering to obtain the second sulfur-containing flue gas and ceramsite lightweight aggregate. According to the treatment method, on the premise that harmlessness, reduction and recycling of the electrolytic metal manganese slag are achieved, the potential value of the manganese slag is fully excavated, the additional value of the manganese slag product is higher, meanwhile, the production cost and product indexes can be better improved through the solid waste synergistic effect, and multiple purposes are achieved at one stroke.

Description

Technical Field

[0001] The present invention relates to the technical field of metallurgy, and particularly relates to a method for treating electrolytic manganese residue. Background Art

[0002] Electrolytic manganese residue (hereinafter referred to as EMR) is a solid waste obtained from manganese ore. Specifically, after the manganese ore is ground, it is leached with sulfuric acid solution, and the industrial waste residue discharged after pressure filtration generally has a moisture content of about 30%. EMR is a fine-grained black solid waste, which is acidic or weakly acidic, and has a density of 2-3 g / cm 3 , and after direct discharge, the moisture content will be higher due to the rainwater that can be stored, showing a muddy paste; after air drying, the particles will agglomerate together and have a certain mud plasticity. According to different ore grades and production processes, for every 1 ton of electrolytic manganese produced, the average amount of manganese residue discharged is 8-10 tons. Therefore, the output of electrolytic manganese residue is large. If only treated by stacking, landfilling and other methods, it will occupy a large amount of land resources. Moreover, electrolytic manganese residue contains toxic and harmful substances such as soluble sulfates, heavy metals, and residual acids, which will cause serious ecological impacts on the soil and groundwater in the discharge area and its surrounding areas. It is urgent to carry out harmless and resourceful treatment of electrolytic manganese residue.

[0003] Due to the requirements of the electrolytic manganese process, EMR often contains ammonia, elements such as Ca, Al, Si, Mn, S, and a small amount of elements such as Cr, Ni, Zn, Cu, etc., but the content of non-ferrous metals is very low and the recovery value is small. Since EMR contains relatively high amounts of sulfates such as calcium sulfate, manganese sulfate, and iron sulfate, the main current ways of treating and resourcefully using it are to replace gypsum for making cement retarders, producing cement concrete, wall materials and other building materials.

[0004] However, the high content of sulfates and residual acids in electrolytic manganese residue will reduce the cement setting rate and affect the cement performance when used in large quantities. The original manganese residue and the calcined manganese residue have low hydration activity due to the lack of composition adjustment and activation treatment, limited application scope and dosage, low product added value, and have not been widely promoted and applied. In addition, electrolytic manganese residue contains harmful substances such as ammonium sulfate and heavy metal ions. If directly applied to building materials production, it will affect the production process and cause phenomena such as easy frosting and cracking and poor quality of the products; at the same time, these heavy metals will enter the water environment with rainwater, threatening ecological safety. Therefore, in view of the deficiencies of the existing methods for treating electrolytic manganese residue, the present invention proposes a method for treating electrolytic manganese residue. Summary of the Invention

[0005] In order to solve the deficiencies of the method for treating electrolytic manganese residue, the present invention proposes a method for treating electrolytic manganese residue. The above object can be achieved by the following implementation modes of the technical solutions: A method for treating electrolytic manganese residue, comprising the following steps: Step 1: Dry the electrolytic manganese residue to obtain dry manganese residue and ammonia-containing wet flue gas; Step 2 and / or Step 3; The said Step 2 includes: Mix the dry manganese residue with an activator and a reducing agent and then roast to obtain the first sulfur-containing flue gas and high-temperature roasted slag; Crush the high-temperature roasted slag to obtain active micropowder; The roasting temperature is 900~1050°C; The said Step 3 includes: Grind and mix the dry manganese residue with coal-based solid waste, add a pore-forming agent for granulation to obtain green pellets, and sinter to obtain the second sulfur-containing flue gas and ceramsite lightweight aggregate.

[0006] Optionally, the electrolytic manganese residue is air-dried electrolytic manganese residue with a water content of 15%~20%. Typically and non-limitingly, the electrolytic manganese residue can be naturally air-dried for 2~3 days to obtain air-dried electrolytic manganese residue; and since the manganese residue will naturally agglomerate due to its own certain viscoplasticity after air-drying, the obtained air-dried electrolytic manganese residue can be broken up to a particle size of less than 20 mm and then subjected to the subsequent drying step.

[0007] Optionally, in Step 1, the drying treatment is carried out at 400~600°C, the drying time is 20~60 min, and the water content in the dry manganese residue is controlled to be less than 5%. Avoiding the decomposition of sulfur-containing compounds during drying at too high a temperature, so as to prevent the separation of sulfur and ammonia from being realized.

[0008] Optionally, Step 1 further includes preparing ammonia water from the ammonia-containing wet flue gas. The prepared ammonia water can be returned to the electrolytic manganese step for use to realize the recycling of materials.

[0009] Optionally, it further includes the step of screening the dry manganese residue to obtain manganese slag pellets and manganese slag fines; Further optionally, the oversize material with a size greater than or equal to 5 mm is manganese slag pellets, and the undersize material with a size less than 5 mm is manganese slag fines; Even more optionally, the manganese slag pellets participate in Step 2, and the manganese slag fines participate in Step 3. Screening the materials according to the particle size in advance can reduce the generation of dust in the subsequent processes.

[0010] Optionally, the activator in Step 2 includes at least one of phosphogypsum slag, mine dust sludge, and mine waste rock; Further optionally, the mine dust sludge includes limestone mine dust sludge. Mine dust sludge is waste such as fine dust generated during ore mining and the mud formed after it encounters water; Mine waste rock is the rock stripped during the mining process.

[0011] Optionally, the reducing agent includes at least one of anthracite, coke, and semi-coke.

[0012] Optionally, the mass ratio of the dried manganese slag, activator, and reducing agent in the second step is 100:5-20:3-8.

[0013] Optionally, the roasting time in the second step is 1-2 h.

[0014] Optionally, in the second step, the high-temperature roasted slag is pulverized, and its residue on a 45-μm sieve is controlled to be not more than 15%, and the specific surface area is not less than 350 m 2 / kg.

[0015] Optionally, an admixture is added during the pulverization process, and the mass of the admixture is 0.1%-5% of the high-temperature roasted slag. The admixture includes grinding aids, proprietary activators, etc., and can be selected as needed or used in a certain proportion, such as sodium silicate can be used as an admixture to stimulate the release of more reactive silica, alumina, etc. from the material and improve the compressive strength of the material.

[0016] Optionally, the weight ratio of the dried manganese slag, coal-based solid waste, and pore-forming agent in the third step is 100:30-50:10-30.

[0017] Optionally, the dried manganese slag, coal-based solid waste, and pore-forming agent are collectively referred to as dry materials, and the water spraying amount during pelletizing in the third step accounts for 8%-18% of the total amount of dry materials.

[0018] Optionally, the diameter of the green pellets is 10-20 mm. Typically and non-limitingly, a disk pelletizer, a cylindrical pelletizer, etc. can be used for pelletizing.

[0019] Optionally, the pore-forming agent is an organic biomass pore-forming agent.

[0020] Optionally, the coal-based solid waste includes at least one of coal gangue, fly ash, and slag.

[0021] Optionally, the pore-forming agent includes at least one of straw, rice husk, and sawdust; further optionally, the particle size of the pore-forming agent is ≤2 mm.

[0022] Optionally, the sintering temperature in the third step is 1050-1180 °C, and the sintering time is 10-30 min.

[0023] Optionally, in the third step, the oversized materials with a size greater than or equal to 5 mm are sieved out after sintering as lightweight ceramsite aggregates. During sintering, due to the influence of the nature of the raw materials themselves, large pieces of materials will inevitably adhere. The adhered ceramsite can be separated by an appropriate cracking method and then screened; the undersized materials can be sold as ceramsite sand or returned to the process of grinding the fine manganese slag and coal-based solid waste.

[0024] Optionally, in step three, before sintering, there is also a step of aging the green balls. Aging can enhance the strength of the green balls and reduce the wear of the green balls during the process of entering and leaving the transport bins.

[0025] Optionally, it includes the step of preparing sulfuric acid using the first sulfur-containing flue gas and / or the second sulfur-containing flue gas as raw materials. During the roasting process of step two and the sintering process of step three, sulfur-containing compounds such as sulfates in the dried manganese slag will decompose to generate sulfur-containing flue gas. The sulfur-containing flue gas can be used to prepare sulfuric acid after dust removal and can further be used to prepare other products containing sulfate radicals. Moreover, the sulfur content in the first sulfur-containing flue gas and the second sulfur-containing flue gas obtained in the present invention is relatively high, which can be used to prepare concentrated sulfuric acid. The concentrated sulfuric acid prepared can be returned to the electrolytic manganese process for use, realizing the recycling of materials.

[0026] In the electrolytic metal manganese slag treatment method provided by the present invention, the active micropowder prepared in step two can be sold as building materials, filling materials, etc., and the lightweight ceramsite aggregate prepared in step three can be sold as building materials, etc.

[0027] The technical solution of the present invention has the following advantages: The process of the present invention can realize the staged extraction and conversion of residual ammonium sulfate components in manganese slag to produce chemical products such as ammonia water and concentrated sulfuric acid, and can also jointly produce active micropowder and lightweight ceramsite aggregate from solid manganese slag. It can flexibly change the product production mode according to market demand, with fast market adaptability. This process can achieve continuous treatment, with high production efficiency, high thermal efficiency, low energy consumption, and little environmental pollution. It has the characteristics of better product performance, more product types, high product added value, high total output value, and good adaptability of process raw materials. At the same time, the diversification of products also enhances the market adaptability of this process. On the premise of realizing the harmlessness, reduction, and resource utilization of electrolytic metal manganese slag, the present invention also fully explores the potential value of electrolytic metal manganese slag, making the electrolytic metal manganese slag products have higher added value, and can improve production costs and product indicators through the solid waste synergistic effect, achieving multiple benefits. Description of the Drawings

[0028] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 It is a process flow schematic diagram of the treatment method provided in Embodiments 1 to 6 of the present invention. Detailed Embodiments

[0030] The various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation on the present invention, but rather as a more detailed description of certain aspects, features, and implementation manners of the present invention. It should be understood that the terms described in the present invention are only for describing particular embodiments and are not used to limit the present invention.

[0031] In addition, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0032] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention.

[0033] Regarding the use of "comprising", "including", "having", "containing", etc. herein, they are all open-ended terms, meaning including but not limited to.

[0034] The electrolytic manganese residue treatment method provided by the present invention includes the following steps: Step 1: Dry the electrolytic manganese residue to obtain dry manganese residue and ammonia-containing wet flue gas; Step 2 and / or Step 3; Step 2 includes: Mix the dry manganese residue with an activator and a reducing agent and then roast to obtain a first sulfur-containing flue gas and high-temperature roasted slag; Crush the high-temperature roasted slag to obtain active micropowder; The roasting temperature is 900-1050°C; Step 3 includes: Grind and mix the dry manganese residue with coal-based solid waste, add a pore-forming agent for granulation to obtain green pellets, and sinter to obtain a second sulfur-containing flue gas and ceramsite lightweight aggregate. Step 1 is a drying and deammoniation process, and Steps 2 and 3 are a micropowder roasting process and a ceramsite sintering process respectively; Subsequently, steps for preparing ammonia water from the ammonia-containing wet flue gas or preparing sulfuric acid from the sulfur-containing flue gas obtained in Steps 2 and 3 can be added according to needs. Then the entire electrolytic manganese residue treatment process is mainly divided into a drying and deammoniation process, a micropowder roasting process, and a ceramsite sintering process, and can also be connected to a chemical ammonia recovery and sulfuric acid production process. The purposes of each process are different and are organically connected together. The present invention changes the way of directly roasting electrolytic manganese residue in a kiln in the prior art. In terms of desulfurization of electrolytic manganese residue, it is to obtain solid products and sulfur-containing flue gas simultaneously through a pretreatment drying step and the synergistic effect of activated solid waste. For the preparation process of active micropowder, on the one hand, it improves the activity of the active micropowder prepared from high-temperature roasted slag and improves the utilization rate of high-temperature roasted slag; on the other hand, it can also increase the concentration of sulfur dioxide in the sulfur-containing flue gas, reduce the cost of the subsequent sulfuric acid preparation step, and at the same time reduce the roasting energy consumption. The control of the roasting temperature further reduces the sulfur content in the obtained active micropowder and also improves the activity index of the product. For the preparation process of ceramsite lightweight aggregate, it is to improve the sintering characteristics of the obtained ceramsite through a pretreatment drying step and the synergistic effect of coal-based solid waste, add a pore-forming agent for granulation, sinter to prepare ceramsite lightweight aggregate and sulfur-containing flue gas; At the same time, a building material ceramsite product and a sulfuric acid product that can be further produced are obtained.

[0035] In some embodiments, before the step of drying the electrolytic manganese residue in Step 1, it further includes the steps of air-drying and dispersing the electrolytic manganese residue. The air-drying can be natural air-drying, and the dispersing is because caking will inevitably occur during the air-drying process, and the air-dried electrolytic manganese residue needs to be dispersed to a particle size less than 20 mm.

[0036] In some embodiments, the drying treatment in Step 1 is carried out at 400-600°C, the drying time is 20-60 min, and the water content in the dry manganese residue is controlled to be less than 5%. When drying, the temperature is below 600°C. Too high a temperature will cause the decomposition of sulfates in the electrolytic manganese residue, making sulfur elements enter the ammonia-containing wet flue gas and unable to effectively separate ammonium sulfate; Too low a temperature results in low drying efficiency and ineffective ammonia recovery.

[0037] In some embodiments, waste heat utilization can be achieved. In the drying and deammoniation process and the fine powder roasting process, the hot dried manganese slag and the hot high-temperature roasted slag can be rapidly cooled by blowing air. The hot air generated during this process can be returned to the electrolytic metal manganese slag drying and deammoniation process for use, or can be used as the combustion-supporting hot air when fuels are burned in various kilns, thereby improving the thermal utilization efficiency of the entire system.

[0038] In some embodiments, renewable energy fuels can be used. For example, biomass raw materials can not only be used as pore-forming agents for ceramsite, but also be used as fuels in various roasting kilns. This can reduce the process carbon consumption index, reduce coal consumption, and also co-process various organic solid wastes.

[0039] Example 1 This example provides a method for treating electrolytic metal manganese slag. The process schematic diagram is referred to Figure 1 , and specifically includes the following steps: (1) After the electrolytic metal manganese slag after pressure filtration is naturally air-dried for 2 days, the moisture content drops to 15%. After being dispersed, it is sent into a drying kiln and dried at 500 °C for 0.5 h, producing dried manganese slag and ammonia-containing wet flue gas. The moisture content of the dried manganese slag is lower than 5%. The ammonia-containing wet flue gas is sent to a chemical plant for ammonia recovery to produce ammonia water.

[0040] (2) The dried manganese slag is screened. The oversize material with a size greater than or equal to 5 mm is manganese slag granular material; the undersize material with a size less than 5 mm is manganese slag fine material.

[0041] (3) Take the manganese slag granular material, use phosphogypsum slag and limestone mine dust (mass ratio 1:1) as activators, and anthracite powder as a reducing agent. After mixing according to the mass ratio of manganese slag granular material: activator: reducing agent = 100:10:4, it is directly put into a roasting kiln and roasted at 1050 °C for about 1 h. The first sulfur-containing flue gas and high-temperature roasted slag are obtained. The high-temperature roasted slag is cooled rapidly by blowing air, and then about 1% of sodium silicate is added and ground until the residue on a 45 μm sieve is lower than 10% and the specific surface area is 410 m 2 / kg, and then active micropowder is obtained. It is detected according to the active index detection method provided in GB / T 2847-2022 (the same below). The 7-day active index is measured to be 72%, and the 28-day active index is 86%. The sulfur content in the active micropowder is 1% and the ammonia content is 0%.

[0042] (4) Take fine manganese slag, use the coal furnace slag after primary grinding as the coal-based solid waste, and use rice husk as the pore-forming agent. Take each raw material according to the mass ratio of fine manganese slag, coal-based solid waste, and pore-forming agent of 100:42:15. First, grind and mix the fine manganese slag and the coal-based solid waste evenly, and then add the pore-forming agent and continue to mix thoroughly. Then, use a disk pelletizer for pelletizing. When pelletizing, the water spraying amount accounts for 12% of the total dry material, the diameter of the green pellets is 10 - 20 mm, and the green balls are aged for 1 day. The aged green pellets are then put into a ceramsite sintering kiln for sintering treatment, and sintered at a temperature of 1150 °C for 15 minutes. Obtain the second sulfur-containing flue gas and the sintered ceramsite. The sintered ceramsite enters the cooling kiln, and after natural cooling, it is discharged from the tail of the cooling kiln. After screening the sintered ceramsite, the oversize material larger than or equal to 5 mm is taken as the ceramsite lightweight aggregate, and the undersize material less than 5 mm is sold as ceramsite sand. The obtained ceramsite lightweight aggregate is detected according to the reference standard GB / T17431.2 - 2010 (the same below), and its cylinder compressive strength is 880 kg / m 3 。

[0043] Send the first sulfur-containing flue gas and the second sulfur-containing flue gas to the chemical process to produce concentrated sulfuric acid.

[0044] Example 2 This example provides a method for treating electrolytic manganese slag, and the process schematic diagram refers to Figure 1 , and specifically includes the following steps: (1) After the electrolytic manganese slag after pressure filtration is naturally air-dried for 2 days, the moisture content drops to 15%. After being broken up, it is sent into a drying kiln and dried at 400 °C for 1 h, producing dried manganese slag and ammonia-containing wet flue gas. The water content of the dried manganese slag is lower than 5%. Send the ammonia-containing wet flue gas to the chemical process to recover ammonia and produce ammonia water.

[0045] (2) Screen the dried manganese slag. The oversize material larger than or equal to 5 mm is the manganese slag granular material; the undersize material less than 5 mm is the fine manganese slag.

[0046] (3) Take the manganese slag granular material, use phosphogypsum slag and limestone mine dust (mass ratio 1:1) as the activator, and use anthracite pulverized coal as the reducing agent. After primary mixing according to the mass ratio of manganese slag granular material, activator, and reducing agent of 100:20:8, directly put it into a roasting kiln and roast at 1050 °C for about 2 h. Obtain the first sulfur-containing flue gas and the high-temperature roasted slag. Blast air-cool the high-temperature roasted slag to quickly cool it, and then add about 1% of sodium silicate and grind it until the residue on a 45 μm sieve is lower than 10% and the specific surface area is not lower than 405 m 2 / kg, and then obtain the active micropowder, whose 7-day activity index reaches 76% and 28-day activity index is 95%. The sulfur content in the active micropowder is 1.2% and the ammonia content is 0%.

[0047] (4) Take fine manganese slag, use fly ash after primary grinding as coal-based solid waste, and use straw as a pore-forming agent. Take each raw material according to the mass ratio of fine manganese slag, coal-based solid waste, and pore-forming agent of 100:30:10. First, grind and mix the fine manganese slag and coal-based solid waste evenly, and then add the pore-forming agent and continue to mix thoroughly. Then, use a disk pelletizer for pelletizing. When pelletizing, the water spraying amount accounts for 14% of the total dry material, the diameter of the green pellets is 10 - 20 mm, and the green balls are aged for 1 day. The aged green balls are then put into a ceramsite sintering kiln for sintering treatment, and sintered at a temperature of 1180 °C for 10 minutes. Obtain the second sulfur-containing flue gas and the sintered ceramsite. The sintered ceramsite enters the cooling kiln and is naturally cooled and discharged from the tail of the cooling kiln. After screening the sintered ceramsite, the oversize material larger than or equal to 5 mm is taken as ceramsite lightweight aggregate, and the undersize material of 5 mm is sold as ceramsite sand. The cylinder compressive strength of the ceramsite lightweight aggregate is 990 kg / m 3 。

[0048] Send the first sulfur-containing flue gas and the second sulfur-containing flue gas to the chemical process to produce concentrated sulfuric acid.

[0049] Example 3 This example provides a method for treating electrolytic manganese slag, and the process schematic diagram refers to Figure 1 and specifically includes the following steps: (1) After the electrolytic manganese slag after pressure filtration is naturally air-dried for 2 days, the moisture content drops to 15%. After being broken up, it is sent into a drying kiln and dried at 600 °C for 20 minutes to produce dried manganese slag and ammonia-containing wet flue gas. The water content of the dried manganese slag is less than 5%. Send the ammonia-containing wet flue gas to the chemical process to recover ammonia and produce ammonia water.

[0050] (2) Screen the dried manganese slag. The oversize material larger than or equal to 5 mm is manganese slag granular material; the undersize material smaller than 5 mm is fine manganese slag.

[0051] (3) Take manganese slag granular material, use phosphogypsum slag and limestone mine dust (mass ratio 1:1) as activators, and use anthracite powder as a reducing agent. After primary mixing according to the mass ratio of manganese slag granular material, activator, and reducing agent of 100:5:3, directly put it into a roasting kiln and roast at 900 °C for about 2 hours. Obtain the first sulfur-containing flue gas and high-temperature roasted slag. Blast air-cool the high-temperature roasted slag to quickly cool it, and then add about 1% of sodium silicate and grind it until the residue on a 45 μm sieve is lower than 10% and the specific surface area is not lower than 410 m 2 / kg, and then obtain active micropowder. Its 7-day activity index reaches 67%, and its 28-day activity index is 84%. The sulfur content in the active micropowder is 0.9% and the ammonia content is 0%.

[0052] (4) Take fine manganese slag, use the coal furnace slag after primary grinding as the coal-based solid waste, and use straw as the pore-forming agent. Take each raw material according to the mass ratio of dry manganese slag, coal-based solid waste, and pore-forming agent of 100:40:15. First, grind and mix the fine manganese slag and the coal-based solid waste evenly, and then add the pore-forming agent for full mixing. Then, use a disk pelletizer for pelletizing. When pelletizing, the water spraying amount accounts for 18% of the total dry material. The diameter of the green pellets is 10 - 20 mm, and the green balls are aged for 1 day. The aged green balls are then put into a ceramsite sintering kiln for sintering treatment, and sintered at a temperature of 1140 °C for 20 min. Obtain the second sulfur-containing flue gas and the sintered ceramsite. The sintered ceramsite enters the cooling kiln, and after natural cooling, it is discharged from the tail of the cooling kiln. After screening, the oversize material larger than or equal to 5 mm of the sintered ceramsite is used as ceramsite lightweight aggregate, and the undersize material less than 5 mm is sold as ceramsite sand. The cylinder compressive strength of the ceramsite lightweight aggregate is 875 kg / m 3 。

[0053] Send the first sulfur-containing flue gas and the second sulfur-containing flue gas to the chemical process to produce concentrated sulfuric acid.

[0054] Example 4 This example provides a method for treating electrolytic manganese slag, and the process schematic diagram refers to Figure 1 and specifically includes the following steps: (1) After the electrolytic manganese slag after pressure filtration is naturally air-dried for 2 days, the moisture content drops to 15%. After being dispersed, it is sent to a drying kiln and dried at 600 °C for 20 min, producing dry manganese slag and ammonia-containing wet flue gas. The water content of the dry manganese slag is lower than 5%. Send the ammonia-containing wet flue gas to the chemical process to recover ammonia and produce ammonia water.

[0055] (2) Screen the dry manganese slag. The oversize material larger than or equal to 5 mm is manganese slag granular material; the undersize material less than 5 mm is fine manganese slag.

[0056] (3) Take the manganese slag granular material, use phosphogypsum slag and limestone mine dust (mass ratio 1:1) as the activator, and use coke as the reducing agent. After primary mixing according to the mass ratio of manganese slag granular material, activator, and reducing agent of 100:20:8, directly put it into a roasting kiln and roast at 900 °C for about 2 h. Obtain the first sulfur-containing flue gas and the high-temperature roasted slag. Blast air-cool the high-temperature roasted slag to quickly cool it, and then add about 1% of sodium silicate and grind it until the residue on a 45 μm sieve is lower than 10% and the specific surface area is not lower than 390 m 2 / kg, and then obtain the active micropowder. Its 7-day activity index reaches 70%, and the 28-day activity index is 85%. The sulfur content in the active micropowder is 1% and the ammonia content is 0%.

[0057] (4) Take manganese slag fine material, use coal furnace slag after primary grinding as coal-based solid waste, and use sawdust as pore-forming agent. Take each raw material according to the mass ratio of manganese slag fine material, coal-based solid waste, and pore-forming agent of 100:30:20. First, grind and mix the manganese slag fine material and coal-based solid waste evenly, then add the pore-forming agent and continue to mix thoroughly. Then, use a disc pelletizer to pelletize. During pelletizing, the water spraying volume accounts for 10% of the total dry material. The diameter of the raw material ball is 10-20mm. The raw material ball is then aged for 1 day. The aged raw material ball is then put into the ceramsite sintering kiln for sintering treatment at 1180℃ for 20 minutes. The second sulfur-containing flue gas and the roasted ceramsite are obtained. The roasted ceramsite enters the cooling kiln and is discharged from the cooling kiln tail after natural cooling. After sintering, the ceramsite is screened and the sieve material of 5mm or more is taken as ceramsite lightweight aggregate, and the sieve material of 5mm or less is taken as ceramic sand. The cylinder compressive strength of ceramsite lightweight aggregate is 970 kg / m 3 .

[0058] The first sulfur-containing flue gas and the second sulfur-containing flue gas are sent to a chemical process to produce concentrated sulfuric acid.

[0059] Example 5 This embodiment provides a method for treating electrolytic manganese slag. Figure 1 , specifically including the following steps: (1) After the electrolytic manganese slag is filtered, it is naturally air-dried for 2 days until the moisture content is reduced to 15%. After being broken up, it is sent to a drying kiln and dried at 600℃ for 20 minutes to produce dry manganese slag and ammonia-containing wet flue gas. The moisture content of the dry manganese slag is less than 5%. The ammonia-containing wet flue gas is sent to the chemical industry to collect ammonia and produce ammonia water.

[0060] (2) The dried manganese slag is screened, and the material on the screen with a size greater than or equal to 5 mm is manganese slag granular material; the material under the screen with a size less than 5 mm is manganese slag fine material.

[0061] (3) Take manganese slag pellets, use phosphogypsum slag and limestone mine dust (mass ratio 1:1) as activators, use coke as reducing agent, mix them according to the mass ratio of manganese slag pellets, activator and reducing agent of 100:15:6, and then directly put them into the roasting kiln for roasting at 900℃ for about 2 hours. The first sulfur-containing flue gas and high-temperature roasting slag are obtained, and the high-temperature roasting slag is blown and air-cooled to make it cool quickly. Then, about 1% of sodium silicate is added and ground to a 45μm sieve residue of less than 10% and a specific surface area of not less than 370m 2 After adding 1000mg / kg of active micropowder, the active micropowder had an activity index of 69% at 7 days and 82% at 28 days. The sulfur content in the active micropowder was 1.1% and the ammonia content was 0%.

[0062] (4) Take the fine manganese slag. Use the coal furnace slag after primary grinding as the coal-based solid waste and sawdust as the pore-forming agent. Take each raw material according to the mass ratio of fine manganese slag, coal-based solid waste, and pore-forming agent of 100:50:30. First, grind and mix the fine manganese slag and the coal-based solid waste evenly, and then add the pore-forming agent for full mixing. Then, use a disk pelletizer for pelletizing. When pelletizing, the water spraying amount accounts for 8% of the total dry material. The diameter of the green pellets is 10 - 20 mm, and the green balls are aged for 1 day. The aged green balls are then put into a ceramsite sintering kiln for sintering treatment, and sintered at a temperature of 1160 °C for 25 min. Obtain the second sulfur-containing flue gas and the sintered ceramsite. The sintered ceramsite enters the cooling kiln and is naturally cooled, and then discharged from the tail of the cooling kiln. After screening the sintered ceramsite, the oversize material larger than or equal to 5 mm is taken as the ceramsite lightweight aggregate, and the undersize material of 5 mm is sold as ceramsite sand. The cylinder compressive strength of the ceramsite lightweight aggregate is 912 kg / m 3 。

[0063] Send the first sulfur-containing flue gas and the second sulfur-containing flue gas to the chemical process to produce concentrated sulfuric acid.

[0064] Example 6 This example provides a method for treating electrolytic manganese slag. The process schematic diagram is referred to Figure 1 , and specifically includes the following steps: (1) After the electrolytic manganese slag after pressure filtration is naturally air-dried for 2 days, the moisture content drops to 20%. After being dispersed, it is sent into a drying kiln and dried at 400 °C for 1 h, producing dried manganese slag and ammonia-containing wet flue gas. The moisture content of the dried manganese slag is lower than 5%. Send the ammonia-containing wet flue gas to the chemical process to recover ammonia and produce ammonia water.

[0065] (2) Screen the dried manganese slag. The oversize material larger than or equal to 5 mm is the manganese slag granular material; the undersize material smaller than 5 mm is the fine manganese slag.

[0066] (3) Take the manganese slag granular material, use phosphogypsum slag and mine waste rock (mass ratio 1:1) as the activator, and semi-coke as the reducing agent. After primary mixing according to the mass ratio of manganese slag granular material, activator, and reducing agent of 100:5:8, directly put it into a roasting kiln and roast at 1000 °C for about 2 h. Obtain the first sulfur-containing flue gas and the high-temperature roasted slag. Blast air-cool the high-temperature roasted slag to quickly cool it, and then add about 1% of sodium silicate and grind it until the residue on a 45 μm sieve is lower than 10% and the specific surface area is not lower than 405 m 2 / kg, and then obtain the active micropowder. Its 7-day activity index reaches 75%, and the 28-day activity index is 86%. The sulfur content in the active micropowder is 0.8% and the ammonia content is 0%.

[0067] (4) Take manganese slag fine material, use coal gangue after primary grinding as coal-based solid waste, and use straw as pore-forming agent. Take each raw material according to the mass ratio of manganese slag fine material, coal-based solid waste, and pore-forming agent of 100:40:20. First, grind and mix the manganese slag fine material and coal-based solid waste evenly, then add the pore-forming agent and continue to mix thoroughly. Then, use a disc pelletizer for pelletizing. During pelletizing, the amount of water sprayed accounts for 14% of the total dry material. The diameter of the raw material ball is 10-20mm. The raw material ball is then aged for 1 day. The aged raw material ball is then put into the ceramsite sintering kiln for sintering treatment at 1050℃ for 30 minutes. The second sulfur-containing flue gas and the roasted ceramsite are obtained. The roasted ceramsite enters the cooling kiln and is discharged from the cooling kiln tail after natural cooling. After sintering, the ceramsite is screened and the sieve material of 5mm or more is taken as ceramsite lightweight aggregate, and the sieve material of 5mm or less is taken as ceramic sand. The cylinder compressive strength of ceramsite lightweight aggregate is 860 kg / m 3 .

[0068] The first sulfur-containing flue gas and the second sulfur-containing flue gas are sent to a chemical process to produce concentrated sulfuric acid.

[0069] Example 7 This comparative example provides a method for treating electrolytic manganese slag. Compared to Example 1, the only difference is that step (2) is omitted. Instead, the resulting dried manganese slag is divided equally by mass, with half subjected to step (3) and the other half subjected to step (4). The resulting active fine powder has a 7-day activity index of 72% and a 28-day activity index of 84%. The sulfur content of the active fine powder is 0.9%. However, a large amount of dust is generated in the kiln during the preparation process, causing environmental pollution.

[0070] Comparative Example 1 This comparative example provides a method for treating electrolytic manganese slag. The only difference from Example 1 is that the undried electrolytic manganese slag in Example 1 is directly subjected to step (3), i.e., after batching, it is placed in a roasting kiln and roasted at 1050°C for 1 hour. The active micropowder obtained after grinding has a 7-day activity index of 48% and a 28-day activity index of 66%. Because the raw materials were not air-dried or further dried, agglomeration occurred, the particle size increased, and the roasting was insufficient, ultimately resulting in poor particle activation of the active micropowder.

[0071] Comparative Example 2 This comparative example provides a method for treating electrolytic manganese slag. The only difference from Example 1 is that anthracite powder is not added as a reducing agent in step (3). The resulting active fine powder has a 7-day activity index of 52% and a 28-day activity index of 67%. The sulfur content of the active fine powder is 2.8%. This high sulfur content results in poor performance.

[0072] Comparative Example 3 This comparative example provides a method for treating electrolytic manganese slag. Compared with Example 1, the only difference is that the roasting temperature in step (3) is adjusted to 800 °C. The obtained active micro-powder has a 7-day activity index of 48% and a 28-day activity index of 55%. The sulfur content in the active micro-powder is 5.2%. The sulfur content is high and the performance is poor.

[0073] Comparative Example 4 This comparative example provides a method for treating electrolytic manganese slag. Compared with Example 1, the only difference is that no activator is added in step (3). The obtained active micro-powder has a 7-day activity index of 63% and a 28-day activity index of 75%. The sulfur content in the active micro-powder is 1%. The sulfur content is high and the performance is poor.

[0074] Comparative Example 5 This comparative example provides a method for treating electrolytic manganese slag. Compared with Example 1, the only difference is that no coal-based solid waste is added in step (4). The firing yield of the obtained lightweight ceramsite aggregate is less than 50%, which affects the production capacity and efficiency.

[0075] Obviously, the above examples are only for illustration and are not intended to limit the implementation. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all implementations here. The obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A method for treating electrolytic manganese residue, characterized in that It includes the following steps: Step 1: Dry the electrolytic manganese residue to obtain dry manganese residue and ammonia-containing wet flue gas; Step 2 and / or Step 3; The said Step 2 includes: Mix the dry manganese residue with an activator and a reducing agent and then roast to obtain the first sulfur-containing flue gas and high-temperature roasted slag; Crush the high-temperature roasted slag to obtain active micropowder; The roasting temperature is 900~1050°C; The said Step 3 includes: Grind and mix the dry manganese residue with coal-based solid waste, add a pore-forming agent for granulation to obtain green pellets, and sinter to obtain the second sulfur-containing flue gas and ceramsite lightweight aggregate.

2. The electrolytic manganese residue treatment method according to claim 1, wherein The said electrolytic manganese residue is air-dried electrolytic manganese residue with a water content of 15%~20%; And / or, in Step 1, the drying treatment is carried out at 400~600°C, the drying time is 20~60 min, and the water content in the dry manganese residue is controlled to be less than 5%; And / or, Step 1 further includes preparing ammonia water from the ammonia-containing wet flue gas; And / or, it further includes the step of screening the dry manganese residue to obtain manganese residue pellets and manganese residue fines.

3. The electrolytic manganese residue treatment method according to claim 2, wherein In the step of screening the dry manganese residue to obtain manganese residue pellets and manganese residue fines, the oversize material with a size greater than or equal to 5 mm is manganese residue pellets, and the undersize material with a size less than 5 mm is manganese residue fines.

4. The electrolytic manganese residue treatment method according to claim 3, wherein, The said manganese residue pellets participate in Step 2, and the said manganese residue fines participate in Step 3.

5. The electrolytic manganese residue treatment method according to claim 1, characterized in that The activator in the said Step 2 includes at least one of phosphogypsum residue, mine dust sludge, and mine waste rock; And / or, the reducing agent includes at least one of anthracite, coke, and semi-coke; And / or, in the said Step 2, the mass ratio of the dry manganese residue, activator, and reducing agent is 100:5~20:3~8.

6. The electrolytic manganese residue treatment method according to claim 1, wherein The roasting time in the said Step 2 is 1~2 h.

7. The electrolytic manganese residue treatment method according to claim 1, wherein, In the said Step 3, the mass ratio of the dry manganese residue, coal-based solid waste, and pore-forming agent is 100:30~50:10~30; And / or, collectively refer to the dry manganese residue, coal-based solid waste, and pore-forming agent as dry materials, and the water spraying amount during granulation in the said Step 3 accounts for 8%~18% of the total mass of the dry materials; And / or, the diameter of the green pellets is 10~20 mm; And / or, the pore-forming agent is an organic biomass pore-forming agent; And / or, the coal-based solid waste includes at least one of coal gangue, fly ash, and coal furnace slag.

8. The electrolytic manganese residue treatment method according to claim 7, wherein The pore-forming agent includes at least one of straw, rice bran, and sawdust.

9. The electrolytic manganese residue treatment method according to claim 1, characterized in that The sintering temperature in the said Step 3 is 1050~1180°C, and the sintering time is 10~30 min; And / or, in the said Step 3, the oversize material with a size greater than or equal to 5 mm is screened and taken as the ceramsite lightweight aggregate after sintering; And / or, in the said Step 3, before sintering, it further includes the step of aging the green pellets.

10. The electrolytic manganese residue treatment method according to claim 1, characterized in that, It includes the step of preparing sulfuric acid from the first sulfur-containing flue gas and / or the second sulfur-containing flue gas as raw materials.

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