Recycling method of electrolytic manganese ammonium sulfate double salt

Abstract

The invention discloses a cyclic utilization method of electrolytic manganese ammonium sulfate double salt. The method comprises the steps that S1, crushed manganese mineral powder is fed into a calcining furnace to be calcined under shielding gas, the typical calcining temperature ranges from 600 DEG C to 700 DEG C, the calcining time ranges from 0.5 h to 5 h, and the main reaction carried out in the calcining furnace is MnCO3 = MnO + CO2 (gas); s2, ammonium sulfate double salt is preheated and dewatered through CO2 released by the calcinator, then the dewatered ammonium sulfate double salt enters the calcinator, the ammonium sulfate double salt and manganese mineral powder are mixed and roasted under the protection of shielding gas, the typical roasting temperature can be 500 DEG C, the roasting time is 1-10 hours, and the main reaction carried out in the calcinator is MnO + (NH4) 2SO4 = MnSO4 + 2NH3 superscript + H2O superscript. According to the cyclic utilization method of the electrolytic manganese ammonium sulfate double salt, the manganese mineral powder is activated by using the ammonium sulfate double salt, so that the reuse of sulfate radicals is realized, and the requirement on sulfuric acid in the leaching process is obviously reduced.

Description

Technical Field

[0001] The invention relates to the technical field of solid waste resource utilization, in particular to a recycling method of electrolytic manganese ammonium sulfate double salt. Background Art

[0002] Electrolytic manganese ammonium sulfate complex salt is a solid waste generated during the electrolytic production of metallic manganese, mainly comprising ammonium sulfate, manganese sulfate and magnesium sulfate. The source of ammonium sulfate is sulfuric acid dissolution of manganese ore and ammonia water adjustment of the pH value of the electrolyte. Every ton of metallic manganese produced will produce 1.2 tons of ammonium sulfate complex salt. The large accumulation of ammonium sulfate complex salt not only wastes precious resources, but also seriously pollutes the environment. The existing methods for treating ammonium sulfate complex salt are mostly for recovering manganese and magnesium, and less for treating ammonium sulfate. The main methods for recycling ammonium sulfate include high-temperature calcination deamination, calcium oxide deamination, and low-temperature catalytic production of ammonia water and sulfuric acid by ammonium sulfate. These methods either have complicated processes or introduce new substances, causing new pollution problems.

[0003] The decomposition of ammonium sulfate can simultaneously recover SO2 and ammonia water, which is an important way to realize the recycling of ammonium sulfate. Since ammonium sulfate double salt is produced in the process of preparing electrolyte from manganese ore powder, the use of ammonium sulfate double salt to pretreat manganese ore powder is an ideal recycling method for ammonium sulfate solid waste. The reaction of ammonium sulfate and manganese carbonate (the main component of manganese ore) to generate manganese sulfate will not only significantly reduce the amount of sulfuric acid used in the acid leaching process of manganese ore powder, but also realize the recovery of ammonia. Patent CN111825106 reports a two-stage calcination treatment method for electrolytic manganese ammonium sulfate double salt, which uses ammonium sulfate double salt and manganese ore powder for mixed calcination, and recovers ammonia water and sulfuric acid at the same time. The chemical reaction involved in this method is:

[0004]

[0005] However, the SO2 and NH3 released simultaneously by this method are difficult to separate and recover, and the reaction temperature of ammonium sulfate double salt and manganese ore powder is seriously mismatched with their decomposition temperature range, resulting in the inability of ammonium sulfate double salt to fully react with manganese ore powder, making it difficult to obtain manganese sulfate, and thus realize the recycling of sulfate and ammonia. Summary of the invention

[0006] The object of the present invention is to provide a recycling method for electrolytic manganese ammonium sulfate double salt to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for recycling electrolytic manganese ammonium sulfate double salt comprises the following steps:

[0009] S1: The crushed manganese ore powder is sent to the calcining furnace for calcination under protective gas. The typical calcination temperature is 600-700℃ and the calcination time is 0.5-5 hours. The main reactions in the calcining furnace are:

[0010] MnCO3=MnO+CO2↑;

[0011] S2: The ammonium sulfate double salt is preheated and dehydrated by using the CO2 released by the calcining furnace. The dehydrated ammonium sulfate double salt then enters the calcining furnace and is mixed with manganese ore powder for roasting under the protection of protective gas. The typical roasting temperature can be 500°C and the roasting time is 1-10 hours. The main reactions carried out in the roasting furnace are:

[0012] MnO+(NH4)2SO4=MnSO4+2NH3↑+H2O↑;

[0013] S3: absorbing the cooled NH3 with water to obtain ammonia water;

[0014] S4: The solid mixture obtained in the roasting furnace is cooled in an inert atmosphere. After cooling, the solid mixture is leached with a leaching liquid to obtain MnSO4 and solid slag.

[0015] As a further solution of the present invention: the calcining furnace and the roasting furnace are rotary kilns, muffle furnaces or fluidized beds, and the "one calcination and one roasting" process is used to achieve the simultaneous preparation of manganese sulfate and ammonia water. The "one calcination and one roasting" two-unit operation is carried out in a rotary kiln or fluidized bed, and can also be carried out in a two-stage furnace or two independent single-stage furnaces.

[0016] As a further solution of the present invention: the "one calcination" refers to the high-temperature calcination of manganese ore powder, and the "one roasting" refers to the mixed roasting of manganese ore powder and ammonium sulfate double salt.

[0017] As a further solution of the present invention: the protective gas can be an inert atmosphere such as nitrogen, or a reducing atmosphere or a weak oxidizing atmosphere such as CO2.

[0018] As a further solution of the present invention: the ammonium sulfate double salt can be the ammonium sulfate double salt directly obtained during the electrolysis process, or can be the ammonium sulfate double salt after recovering manganese and magnesium.

[0019] As a further solution of the present invention: the leaching liquid can be water or 0.1-5 molar sulfuric acid.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The recycling method of electrolytic manganese ammonium sulfate double salt uses ammonium sulfate double salt to activate manganese ore powder, realizes the reuse of sulfate ions, and significantly reduces the demand for sulfuric acid in the leaching process.

[0022] 2. The recycling method of the electrolytic manganese ammonium sulfate double salt reduces the demand for additional ammonia water in the manganese sulfate electrolyte process by recovering ammonia.

[0023] 3. The recycling method of electrolytic manganese ammonium sulfate double salt uses the generated CO2 and NH3 to preheat the ammonium sulfate double salt and manganese ore powder, saving energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The present invention is a process diagram of a recycling method of electrolytic manganese ammonium sulfate double salt. DETAILED DESCRIPTION

[0025] Embodiment 1

[0026] See also Figure 1 In an embodiment of the present invention, a method for recycling electrolytic manganese ammonium sulfate double salt comprises the following steps:

[0027] S1: The crushed manganese ore powder is sent to the calcining furnace for calcination under protective gas. The typical calcination temperature is 700℃ and the calcination time is 1 hour. The main reactions in the calcining furnace are:

[0028] MnCO3=MnO+CO2↑;

[0029] S2: The ammonium sulfate double salt is preheated and dehydrated by using the CO2 released by the calcining furnace. The dehydrated ammonium sulfate double salt then enters the calcining furnace and is mixed with manganese ore powder for roasting under the protection of protective gas. The typical roasting temperature can be 500°C and the roasting time is 1-10 hours. The main reactions carried out in the roasting furnace are:

[0030] MnO+(NH4)2SO4=MnSO4+2NH3↑+H2O↑;

[0031] S3: absorbing the cooled NH3 with water to obtain ammonia water;

[0032] S4: The solid mixture obtained in the roasting furnace is cooled in an inert atmosphere. After cooling, the solid mixture is leached with a leaching liquid to obtain MnSO4 and solid slag.

[0033] As a further solution of the present invention: the calcining furnace and the roasting furnace are rotary kilns, muffle furnaces or fluidized beds, and the "one calcination and one roasting" process is used to achieve the simultaneous preparation of manganese sulfate and ammonia water. The "one calcination and one roasting" two-unit operation is carried out in a rotary kiln or fluidized bed, and can also be carried out in a two-stage furnace or two independent single-stage furnaces.

[0034] As a further solution of the present invention: the "one calcination" refers to the high-temperature calcination of manganese ore powder, and the "one roasting" refers to the mixed roasting of manganese ore powder and ammonium sulfate double salt.

[0035] As a further solution of the present invention: the protective gas can be an inert atmosphere such as nitrogen, or a reducing atmosphere or a weak oxidizing atmosphere such as CO2.

[0036] As a further solution of the present invention: the ammonium sulfate double salt can be the ammonium sulfate double salt directly obtained during the electrolysis process, or can be the ammonium sulfate double salt after recovering manganese and magnesium.

[0037] As a further solution of the present invention: the leaching liquid can be water or 0.1-5 molar sulfuric acid.

[0038] The method described in this embodiment includes calcining manganese ore powder, roasting the calcined manganese ore powder and ammonium sulfate double salt, absorbing ammonia, cooling and leaching the roasted mixture. First, the manganese ore powder is calcined in a muffle furnace at a temperature of 700° C. for 1 hour. Then, the ammonium sulfate double salt directly obtained in the electrolysis process and the calcined manganese ore powder are roasted under nitrogen protection at a roasting temperature of 500° C. The obtained solid mixture is leached in water to obtain a manganese sulfate solution and solid slag. Experimental results show that: in the mixture of ammonium sulfate double salt directly roasted at 500° C. and manganese ore powder, 100% of the ammonium sulfate double salt undergoes decomposition reaction and does not react with the manganese ore powder. The amount of manganese leached in water is 3%, which comes from the manganese sulfate in the ammonium sulfate double salt. In comparison, in the mixture obtained by "calcining and roasting", 77% of the ammonium sulfate reacts with the manganese ore powder, and the amount of manganese leached in water is 75%.

[0039] Embodiment 2

[0040] See also Figure 1 In an embodiment of the present invention, a method for recycling electrolytic manganese ammonium sulfate double salt comprises the following steps:

[0041] S1: The crushed manganese ore powder is sent to the calcining furnace for calcination under protective gas. The typical calcination temperature is 600℃ and the calcination time is 1 hour. The main reactions in the calcining furnace are:

[0042] MnCO3=MnO+CO2↑;

[0043] S2: The ammonium sulfate double salt is preheated and dehydrated by using the CO2 released by the calcining furnace. The dehydrated ammonium sulfate double salt then enters the calcining furnace and is mixed with manganese ore powder for roasting under the protection of protective gas. The typical roasting temperature can be 500°C and the roasting time is 1-10 hours. The main reactions carried out in the roasting furnace are:

[0044] MnO+(NH4)2SO4=MnSO4+2NH3↑+H2O↑;

[0045] S3: absorbing the cooled NH3 with water to obtain ammonia water;

[0046] S4: The solid mixture obtained in the roasting furnace is cooled in an inert atmosphere. After cooling, the solid mixture is leached with a leaching liquid to obtain MnSO4 and solid slag.

[0047] As a further solution of the present invention: the calcining furnace and the roasting furnace are rotary kilns, muffle furnaces or fluidized beds, and the "one calcination and one roasting" process is used to achieve the simultaneous preparation of manganese sulfate and ammonia water. The "one calcination and one roasting" two-unit operation is carried out in a rotary kiln or fluidized bed, and can also be carried out in a two-stage furnace or two independent single-stage furnaces.

[0048] As a further solution of the present invention: the "one calcination" refers to the high-temperature calcination of manganese ore powder, and the "one roasting" refers to the mixed roasting of manganese ore powder and ammonium sulfate double salt.

[0049] As a further solution of the present invention: the protective gas can be an inert atmosphere such as nitrogen, or a reducing atmosphere or a weak oxidizing atmosphere such as CO2.

[0050] As a further solution of the present invention: the ammonium sulfate double salt can be the ammonium sulfate double salt directly obtained during the electrolysis process, or can be the ammonium sulfate double salt after recovering manganese and magnesium.

[0051] As a further solution of the present invention: the leaching liquid can be water or 0.1-5 molar sulfuric acid.

[0052] The method described in this embodiment includes calcining manganese ore powder, roasting the calcined manganese ore powder and ammonium sulfate double salt, absorbing ammonia, cooling and leaching the roasted mixture. First, the manganese ore powder is calcined in a muffle furnace at a temperature of 600° C. for 1 hour. Then, the ammonium sulfate double salt directly obtained in the electrolysis process and the calcined manganese ore powder are roasted under nitrogen protection at a roasting temperature of 500° C. The obtained solid mixture is leached in water to obtain a manganese sulfate solution and solid slag. Experimental results show that 62% of the ammonium sulfate in the mixture obtained by "calcining and roasting" reacts with the manganese ore powder, and the manganese leaching amount in water is 60%.

[0053] It should be noted that the above embodiments all belong to the same inventive concept, and the description of each embodiment has its own focus. For matters that are not described in detail in some embodiments, reference may be made to the description in other embodiments.

[0054] The above-mentioned embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for recycling electrolytic manganese ammonium sulfate double salt, characterized in that: The steps include: S1: The crushed manganese ore powder is sent to the calcining furnace for calcination under protective gas. The typical calcination temperature is 600-700℃ and the calcination time is 0.5-5 hours. The main reactions in the calcining furnace are: MnCO3=MnO+CO2↑; S2: The ammonium sulfate double salt is preheated and dehydrated by using the CO2 released by the calcining furnace. The dehydrated ammonium sulfate double salt then enters the calcining furnace and is mixed with manganese ore powder for roasting under the protection of protective gas. The typical roasting temperature can be 500°C and the roasting time is 1-10 hours. The main reactions carried out in the roasting furnace are: MnO+(NH4)2SO4=MnSO4+2NH3↑+H2O↑; S3: absorbing the cooled NH3 with water to obtain ammonia water; S4: The solid mixture obtained in the roasting furnace is cooled in an inert atmosphere. After cooling, the solid mixture is leached with a leaching liquid to obtain MnSO4 and solid slag.

2. The recycling method of an electrolytic manganese ammonium sulfate double salt according to claim 1, characterized in that: The calcining furnace and the roasting furnace are rotary kilns, muffle furnaces or fluidized beds, and the "one calcination and one roasting" process is used to simultaneously prepare manganese sulfate and ammonia water. The "one calcination and one roasting" two-unit operation is carried out in a rotary kiln or fluidized bed, and can also be carried out in a two-stage furnace or two independent single-stage furnaces.

3. The recycling method of an electrolytic manganese ammonium sulfate double salt according to claim 3, characterized in that: The "one calcination" refers to the high-temperature calcination of manganese ore powder, and the "one roasting" refers to the mixed roasting of manganese ore powder and ammonium sulfate double salt.

4. The recycling method of an electrolytic manganese ammonium sulfate double salt according to claim 1, characterized in that: The protective gas may be an inert atmosphere such as nitrogen, or a reducing atmosphere or a weakly oxidizing atmosphere such as CO2.

5. The method for recycling electrolytic manganese ammonium sulfate double salt according to claim 1, characterized in that: The ammonium sulfate double salt may be the ammonium sulfate double salt directly obtained during the electrolysis process, or may be the ammonium sulfate double salt obtained after manganese and magnesium are recovered.

6. The method for recycling electrolytic manganese ammonium sulfate double salt according to claim 1, characterized in that: The leaching solution may be water or 0.1-5 molar sulfuric acid.

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