Method for microwave treatment of manganese nodule

Abstract

The invention belongs to the technical field of deep sea manganese nodule treatment, and particularly relates to a method for microwave treatment of manganese nodules. When manganese nodules are treated in the prior art, the defects that an additional reducing agent needs to be added, a large amount of by-product gas polluting the environment exists in products, the reaction rate is low, the treatment time is long, energy consumption is high, pollution is large, and the separation efficiency of gangue components in minerals is low exist. In order to solve the problems, the method for microwave treatment of the manganese nodule comprises the following steps of microwave preheating activation, ore grinding premixing, microwave reduction acid leaching, sulfuration precipitation, microwave sulfuration smelting, oxygen-enriched blowing, microwave roasting oxygen pressure leaching, multi-stage extraction and microwave treatment. And the structure of the manganese-containing aggregate in the raw ore is destroyed, and gas-phase components in the raw ore overflow, so that the leaching rate and the recovery rate of valuable metals are greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of deep-sea manganese nodule processing, and particularly relates to a method for processing manganese nodules with microwaves. Background Art

[0002] Deep-sea manganese nodules are also called deep-sea polymetallic nodules. In the process of developing and utilizing deep-sea polymetallic nodule resources, smelting is an important link. So far, more than 30 methods for treating polymetallic nodules have been proposed at home and abroad. The number of methods and the breadth of ideas are beyond the reach of any land mine, and new treatment methods are still being explored. According to literature reports, the current polymetallic nodule treatment methods can be roughly divided into two categories: fire-wet combined process and full wet process.

[0003] The following methods are widely used (the "valuable metals" mentioned below refer specifically to metals with recovery value such as Mn, Fe, Cu, Co, Ni, etc. in deep-sea manganese nodules): Reduction smelting-leaching process: The basic principle of smelting alloys with polymetallic nodules as raw materials is to use the difference in properties that Mn is difficult to reduce to metal (its oxide free energy is high), while Fe, Ni, Co, Cu and other oxides are easier to reduce to metal. Ni, Co, Cu and Fe in the valuable metals are selectively reduced at high temperature, and Mn is reduced from high-valent oxides to MnO and enters the slag phase. Reduction smelting obtains high-iron alloys and manganese-rich slag enriched with major metals. Various metals are recovered and separated from the alloy phase by hydrometallurgical methods, and the manganese-rich slag is further reduced while hot to prepare silicon-manganese alloy.

[0004] Reduction smelting-sulfidation-leaching process: first, the dried manganese nodules are selectively reduced and smelted with a carbonaceous reducing agent at a temperature of about 1420°C to produce manganese-rich slag and Cu-Ni-Co-Fe alloy; then the Cu-Ni-Co-Fe alloy is roasted and oxidized to remove most of the Fe and residual Mn, and then pyrite, gypsum and other sulfiding agents are added to convert Cu, Co, Ni and residual Fe in the alloy into sulfides to form low matte; then the low matte is oxidized and blown at a temperature of about 1350°C to remove the iron therein to obtain high matte; finally, the obtained high matte is ground and slurried and then oxygen pressure leached with sulfuric acid as the leaching agent to obtain Cu, Co and Ni solutions, and Cu, Ni, Co and other products in the valuable metals are recovered by solvent extraction, electrolysis and precipitation; and the manganese-rich slag is reduced and smelted with lime at a temperature of 1600°C to produce qualified manganese alloy.

[0005] Roasting-leaching process: Based on the chemical composition and mineral characteristics of polymetallic nodules, polymetallic nodules are roasted for pretreatment to change the mineral structure and make it easier to handle, and then the valuable metals are recovered by wet process. Roasting methods include chlorination roasting, sulphation roasting and reduction roasting, and leaching methods include acid leaching, ammonia leaching and water leaching.

[0006] The above-mentioned prior art mainly uses pyrometallurgical roasting / smelting to first make Mn enter the slag phase, and strategic metals such as Fe, Co, Cu, Ni enter the alloy phase or matte phase, and then separate the above strategic metals by hydrometallurgical methods, or simply prepare them into alloys directly. No matter which method is used, its essence is to separate Mn from strategic metals such as Fe, Co, Cu, Ni, etc.

[0007] The above method has the following disadvantages: (1) the pyrometallurgical roasting / smelting step requires the addition of additional reducing agents, such as carbon powder, coke, coal powder, etc., and the product contains a large amount of by-product gases such as carbon dioxide, dioxins, carbon sulfides, etc. that pollute the environment and increase the processing cost; the reaction rate is low and the heating time is long; the processes such as grinding, sorting, carbon blending, smelting / roasting, product grinding and sorting have high energy consumption and high pollution, large operating equipment and high construction cost, and complex process; (2) the wet leaching step has a low rate and a long leaching time; the amount of acid used is large, which is easy to produce waste acid; the alloy formed has high hardness and high melting point, and is difficult to handle later; the separation efficiency of gangue components in the mineral is low. Summary of the invention

[0008] In view of the problems existing in the prior art, the present invention provides a method for treating manganese nodules with microwaves. The main components of the deep-sea manganese nodules used include MnO 2 (25%~40%)、SiO 2 (14%~20%), Fe 2 O 3 (5%~10%)、Al 2 O 3 (3%~6%), MgO (1%~5%), CaO (1%~5%), Na 2 O (1%~3%), NiO (1%~3%), CuO (1%~3%), Co 2 O 3 (0.1%~0.3%), etc. The method includes the following contents: (1) Microwave preheating activation: The manganese nodule ore is preheated and activated by microwaves. The structure of manganese agglomerates in the ore is destroyed, and the gas phase components in the ore overflow to obtain activated manganese nodules. The specific method of microwave preheating activation is as follows: use microwave heating with a power of 300W~500W and a frequency of 2.3GHz~2.8GHz to make the temperature of the raw ore 300℃~500℃, keep the microwave frequency unchanged and adjust the microwave power, keep the temperature at this temperature for 20min~30min, so that the structure of manganese aggregates in the raw ore is destroyed, SO 2 , Cl 2 The gas phase components overflow in situ, making the original ore structure loose, producing a large number of voids and holes, and the valuable metal elements are decomposed to obtain activated manganese nodules.

[0009] (2) Grinding and premixing: Grinding the activated manganese nodules prepared in step (1) to obtain activated manganese nodule ore powder, adding a reducing agent, high-grade matte, to the activated manganese nodule ore powder and mixing to obtain a premixed activated ore powder; For every 100g of activated manganese nodule ore powder, add 30g~100g of high-grade matte.

[0010] (3) Microwave reduction acid leaching: under a microwave environment, sulfuric acid as a leaching agent and high-grade matte as a reducing agent are added to the premixed activated ore powder obtained in step (2) to form a leaching system for reduction activation leaching to obtain a microwave acid leaching solution containing Mn, Co, Ni, Cu, Fe ions and impurities and Fe-containing acid leaching residue; Reduction activation leaching makes MnO in the ore powder 2 and Co 2 O 3 The mineral phase is reduced and dissociated, reconstructed into soluble MnSO 4 and CoSO 4 At the same time, the free CuO, NiO and other minerals are dissolved by sulfuric acid and converted into copper sulfate and nickel sulfate.

[0011] The microwave environment is to use microwave heating with a power of 100W to 200W and a frequency of 2.3GHz to 2.8GHz to make the temperature of the reduction activation leaching system 60°C to 100°C, then adjust the microwave power while keeping the microwave frequency unchanged, and keep the temperature for 30min to 60min to perform reduction activation leaching.

[0012] For every 100g of premixed activated ore powder, add 30g~100g of high-grade matte; Every 1g of premixed activated mineral powder corresponds to 7mL~10mL of sulfuric acid, and the concentration of sulfuric acid is 0.6mol / L~1.6mol / L.

[0013] The grade of the high-grade matte in steps (2) and (3) is 60%-75%, and the main components are as follows: Cu 60%-70%, S 20%-25%, Fe 5%-20%; the sum of the above main components is less than 100%; The high-grade matte comes from pre-purchased copper smelting matte raw material or is produced by oxygen-enriched blowing in step (6).

[0014] The microwave acid leaching solution also contains impurities, which include compounds containing elements such as Si, Al, Mg, Ca, and Na in addition to compounds containing Mn, Co, Ni, Cu, and Fe that are not completely leached from the premixed activated ore powder. In this step, the recovery of all valuable metals (Mn, Co, Ni, Cu, and Fe) and the preliminary separation of Fe are achieved (a small part of Fe is dissolved in the microwave acid leaching solution, and most of Fe remains in the acid leaching residue). The Fe-containing acid leaching residue can continue to deeply extract the valuable metals (Mn, Co, Ni, Cu, and Fe) that are not completely leached, or be used as cement aggregate or other building materials.

[0015] (4) Sulfidation precipitation: adding a sulfidation precipitant to the microwave acid leaching solution obtained in step (3) to form a sulfidation system, wherein the Fe, Co, Cu, Ni ions and a small amount of Mn ions in the sulfidation system form sulfidation precipitates such as cobalt sulfide, copper sulfide and nickel sulfide, thereby obtaining a sulfidation demanganeseized slag containing sulfidation precipitates and impurities and a manganese-rich sulfidation solution containing a large amount of Mn ions, thereby achieving the separation of manganese ions; The manganese-rich sulfide liquid is distilled to obtain manganese sulfate crystal products; impurities in the microwave acid leaching liquid are also precipitated into the sulfide demanganese slag to become impurities in the sulfide demanganese slag.

[0016] The sulfide precipitant includes Na 2 S, NaHS, Na 2 SO 3 One or more of the following; Use pH regulator to adjust the pH of the vulcanization system to 2~5; pH regulators include NaOH, NH 3 ·H 2 O、NH 4 At least one of Cl, citric acid, etc.; For every 1000mL of microwave acid leaching solution, 30g~80g of sulfide precipitation agent is added, and the sulfide precipitation time is 30min~60min.

[0017] (5) Microwave sulfidation smelting: adding a reducing agent and a sulfiding agent to the sulfided demanganese slag obtained in step (4) to form a smelting system for smelting under a microwave environment to obtain low-grade matte and sulfided smelting slag; Among them, low-grade matte (matt grade 40%~50%) is mainly formed by the sulfidation of copper, nickel, cobalt, a small amount of Mn and a small part of iron in the sulfidation demanganese slag, thereby achieving the enrichment of copper, nickel and cobalt; the sulfidation smelting slag is mainly formed by most of the iron and impurities in the sulfidation demanganese slag entering the slag phase.

[0018] The microwave environment is to use microwave heating with a power of 900W to 1300W and a frequency of 2.3GHz to 2.8GHz to make the temperature of the melting system 1100°C to 1300°C. After reaching the melting temperature, the microwave frequency is kept unchanged and the microwave power is adjusted to keep the melting system at this temperature for 60min to 120min for melting.

[0019] The mass of the mixture of reducing agent and sulfiding agent added to every 100g of sulfiding demanganizing slag is 130g~200g, wherein the mass of reducing agent is 68g~120g; The reducing agent is carbon powder and the vulcanizing agent is CaSO 4 ; (6) Oxygen-enriched blowing: The low-grade matte and sulfide smelting slag obtained in step (5) are subjected to a first-stage blowing using an oxygen lance. After the first-stage blowing slag is separated, a second-stage blowing is continued. After the second-stage blowing slag is separated, a high-grade matte is obtained.

[0020] The oxygen pressure of the first stage blowing is 200kPa-250kPa, the oxygen enrichment concentration is 50%-60%, and the blowing time is 60min-120min; the purpose of the first stage blowing is to remove iron and a part of sulfur in the low-grade matte to obtain a high-grade matte containing 50%-60% of copper, nickel and cobalt. Generally, the blowing time of the low-grade matte is long; The oxygen pressure of the second stage blowing is 150 kPa-200 kPa, the oxygen enrichment concentration is 40%-50%, the second stage blowing time is 30 min-60 min, and the blowing end point is considered to be reached when the matte phase grade reaches 60%-75%.

[0021] The first stage blowing slag is waste slag and can be used to recover iron; the second stage blowing slag is returned to step (5) for microwave sulfidation smelting and recycling. The high-grade matte can be added to the grinding premixing step (2) and the microwave reduction acid leaching step (3) as a reducing agent.

[0022] (7) Microwave roasting and oxygen pressure leaching: The high-grade matte obtained in step (6) is subjected to roasting and desulfurization treatment by microwave heating to obtain a roasting product; the roasting product is subjected to oxygen pressure leaching under a microwave environment, and after the leaching is completed, solid-liquid separation is performed to obtain an oxygen pressure leaching liquid and an oxygen pressure leaching slag.

[0023] The microwave power of the roasting desulfurization is 500W~800W and the frequency is 2.3GHz~2.8GHz. The high-grade matte temperature is 500℃~800℃ by microwave heating. The microwave power is adjusted while keeping the microwave frequency unchanged, so that the high-grade matte is roasted at this temperature for 30min~120min. During the oxygen pressure leaching, microwave heating with a power of 100W to 200W and a frequency of 2.3GHz to 2.8GHz is first used to make the temperature of the oxygen pressure leaching system 160°C to 200°C. After reaching the target temperature, the microwave frequency is kept unchanged and the microwave power is adjusted to keep the leaching system at this temperature for 60min to 150min, and the pure oxygen pressure is 100kPa to 700kPa.

[0024] Sulfuric acid is used as the leaching solution, the concentration of sulfuric acid is 0.6mol / L~1.6mol / L, and 7mL~10mL of leaching solution is used for every 1g of roasted product; SO generated by roasting 2 After absorption by NaOH, the obtained Na 2 SO 3 It can be recycled as a sulfide precipitant in step (4); the oxygen pressure leaching slag can be deeply purified and separated into metals such as Mn, Co, Ni, Cu, Fe, etc., and can also be used as cement aggregate and building materials.

[0025] (8) Multi-stage extraction: The oxygen pressure leaching solution obtained in step (7) is extracted to separate manganese, copper, nickel and cobalt; The extraction method is as follows: firstly, the leaching solution is subjected to P204 extraction to obtain manganese-containing extract and manganese-removed raffinate, then the manganese-removed raffinate is subjected to Lix984 extraction to obtain copper-containing extract and copper-removed raffinate, then the copper-removed raffinate is subjected to Cyanex272 extraction to obtain cobalt-containing extract and cobalt-removed raffinate, and finally the cobalt-removed raffinate is subjected to P507 extraction to obtain nickel-containing extract and nickel-removed raffinate; The above-mentioned extracts are all organic phases, and the raffinates are all aqueous phases. Back extraction is required to return the extract in the extract to the aqueous phase. The regenerated organic phase containing no or a small amount of extract obtained after back extraction is returned to the corresponding extraction process for continued use.

[0026] The concentration of the extractant is 10%~30% (sulfonated kerosene is used as the diluent), the extraction phase ratio is 0.5~2.5, the mixing time is 5min~15min, the phase separation time is 5min~15min, and the extraction level is 3~9; the conventional H 2 SO 4 Or aqueous solutions of inorganic chemical reagents such as NaOH; through multiple multi-stage extraction and stripping processes, efficient separation of Mn, Cu, Co and Ni is achieved.

[0027] Step (1) Microwave preheating activation: Cobalt, nickel and copper in polymetallic nodules are mainly embedded in the lattice of iron and manganese oxide minerals in the form of isomorphous phases. The results of process mineralogy research show that manganese is mainly present in the minerals in the form of Mn 4+ Exists in oxide form, namely MnO 2 .MnO 2It is very stable under normal conditions and cannot be directly destroyed by sulfuric acid, which leads to a very slow leaching rate of valuable metals and a very low recovery rate. The key to improving the efficiency of valuable metal leaching is to destroy the mineral structure of the nodules, especially the structure of manganese minerals. Through microwave activation, the mineral phase of manganese oxide minerals in the original ore is dissociated and reconstructed. The oxides of cobalt, nickel, copper, etc. bound in the matrix of manganese oxide minerals will be exposed or freed during the dissociation and reconstruction process, which plays a role in component activation, reduces the activation energy of the leaching reaction of cobalt, nickel, and copper, and is conducive to improving the subsequent leaching effect.

[0028] In step (4), according to the sulfide precipitation equilibrium of common metal ions, the solubility products of CoS, CuS, NiS and MnS are quite different. 2+ , Cu 2+ 、Ni 2+ , Mn 2+ Cobalt, nickel, copper and manganese are well separated by precipitating cobalt, nickel, copper and manganese in the microwave acid leaching solution. 2+ Sulfide precipitation transformation will occur simultaneously, with Co 2+ , Cu 2+ 、Ni 2+ They enter the sulfiding and demanganeseizing slag together to achieve deep purification of manganese-rich sulfiding liquid.

[0029] The microwave acid leaching solution is acidic. During the sulfurization precipitation process, the S in the sulfurization system 2- It will be decomposed as follows: S 2- +H 2 O⇋HS - +OH - (1) HS - +H 2 O⇋H 2 S+OH - (2) SO 3 2- +H 2 O⇋HSO 3 - +OH - (3) Increase the pH of the solution (increase [OH - ]) can reduce S 2- and SO 3 2- The decomposition degree of the sulfide precipitant forms S in the sulfide system. 2- -HS - and SO 3 2- -HSO 3- The buffer system, combined with the pH regulator, controls the pH of the vulcanization system at 2~5 to reduce S 2- and SO 3 2- decomposition and consumption, thereby improving the utilization rate of the sulfiding agent. 2+ , Fe 2+ 、Co 2+ , Cu 2+ 、Ni 2+ The key to achieving selective sulfide precipitation in a complex plasma sulfide system is to establish a more appropriate buffer system by regulating the pH of the solution, thereby improving the utilization rate of the sulfiding agent and reducing the process cost while ensuring the deep precipitation of the target metal ions.

[0030] Step (5) During microwave sulfidation smelting, carbon powder C and calcium sulfate CaSO 4 As a reducing agent and sulfiding agent, CaSO 4 Under the action of C, it decomposes into CaS. CaS reacts with the metal oxides MeO (CuO, NiO, CoO, and a small amount of FeO) formed in the sulfidation smelting process to form metal sulfides MeS (Me refers to Cu, Co, Ni, Fe) and CaO. CaO reacts with the impurities in the sulfidation demanganization slag to form sulfidation smelting slag together with the remaining Fe.

[0031] CaSO 4 +C→CaS+CO 2 (4) MeO+CaS→MeS+CaO (5) The process of metal oxide sulfidation transformation may be: CuO→Cu→Cu 2 S (6) NiO→Ni→Ni 3 S 2 (7) CoO→Co→Co 9 S 8 (8) FeO→Fe→FeS (9) During step (6) oxygen-enriched blowing, the affinity of metals to oxygen is in the order of Fe>Co>Ni>Cu. When blowing is carried out under certain oxygen potential conditions, FeS in low-grade matte will be oxidized to form slag first. The basic reaction of iron removal during blowing is: FeS+O 2 →FeO+SO 2 (10) FeO+SiO 2 →FeO·SiO 2 (11) Different from the traditional method of obtaining metal by blowing copper matte, the oxidative blowing of low-grade copper-nickel-cobalt matte in the present invention only involves blowing to remove iron, and then oxygen pressure leaching is performed after obtaining high-grade copper-nickel-cobalt matte.

[0032] As the blowing progresses, most of the iron is removed by slag formation, and the grade of the matte is continuously improved and turned into high-grade matte. When the blowing reaches a certain degree, further blowing will cause oxidation slag reaction of cobalt, nickel and copper, resulting in loss of valuable metals. In order to reduce the loss of valuable metals in the later stage of blowing, we plan to adopt a two-stage blowing method to blow the low-grade matte. The first-stage blowing slag (iron precipitation slag) meets the slag disposal standard, and the second-stage blowing slag is returned to the sulfide smelting.

[0033] In step (7), when microwave roasting and oxygen pressure leaching are performed, if low-temperature oxygen pressure leaching is used for high-grade matte, that is, when the reaction temperature is 100°C to 140°C and oxygen is sufficient, metal sulfides react with oxygen and sulfuric acid to generate metal sulfates and elemental sulfur: MeS+O 2 +H 2 SO 4 →MeSO 4 +H 2 O+S (12) It is accompanied by the following reactions: MeS+H 2 SO 4 →MeSO 4 +H 2 S (Me=Mn, Fe, Cu, Co, Ni) (13) H 2 S+O 2 →H 2 O+S (14) FeSO 4 +O 2 +H 2 SO 4 →Fe 2 (SO 4 ) 3 +H 2 O (15) H 2 S+Fe 2 (SO 4 ) 3 →FeSO 4 +H 2 SO 4 +S (16) MeS+Fe 2 (SO 4 ) 3 →FeSO 4 +MeSO4 +S (17) Fe 2 (SO 4 ) 3 +H 2 O→Fe 2 O 3 +H 2 SO 4 (18) Fe 2 (SO 4 ) 3 +H 2 O+Na 2 SO 4 →Na 2 Fe 6 (SO 4 ) 4 (OH) 12 +H 2 SO 4 (19) At this temperature, the hydrolysis product of iron is not mainly hematite, but the precipitation reaction of sodium ferroaluminate (reaction formula 19) is more dominant. In order to achieve the ideal iron removal effect, adding monovalent cations in or outside the autoclave can effectively remove iron. The monovalent cations can be provided by the raffinate of the subsequent extraction process. The elemental sulfur produced by the reaction and the hydrolysis slag of iron enter the leaching slag together and return to the sulfidation smelting, which can be used as a sulfiding agent and a slag-making agent respectively.

[0034] Temperature has a great influence on the reaction process and results of oxygen pressure leaching of metal sulfides. At relatively low temperatures (100°C~140°C), the sulfur in the metal sulfides is oxidized to elemental sulfur, as shown in reaction equation (12).

[0035] The above is the basic principle of hematite removal by hydrothermal method of hydrometallurgy.

[0036] The elemental sulfur produced by low-temperature oxygen pressure leaching will form a sulfur film on the surface of the mineral, hindering the leaching reaction. In addition, low temperature is not conducive to the precipitation reaction of hematite, and the iron removal effect is poor. Increasing the reaction temperature can effectively avoid these problems. Therefore, we choose high-temperature oxygen pressure leaching.

[0037] In the present invention, when the temperature is relatively high (>160°C), the metal sulfide is directly oxidized to sulfate: MeS+O 2 →MeSO 4 (20) Among them, FeSO 4 Under high temperature and sufficient oxygen, further oxidative hydrolysis will occur: FeSO 4 +O 2+H 2 O→Fe 2 O 3 +H 2 SO 4 (twenty one) After the high-grade matte of the present invention is roasted by microwave, the metal sulfide therein undergoes roasting desulfurization, and the generated SO 2 The escape reduces the sulfur content of the system when oxygen pressure leaching enters the kettle, thereby reducing the sulfuric acid concentration of the system at the end of oxygen pressure leaching, while copper, nickel and cobalt are efficiently leached for hematite (Fe 2 O 3 ) creates favorable conditions to achieve efficient iron removal.

[0038] The beneficial effects of the present invention are as follows: 1. This design proposes to use microwave treatment to release sulfur dioxide and other gases in the mineral, produce some microcracks inside the manganese nodules, produce macroscopic phase interfaces, and cause loose macroscopic structures and changes in mineral phases. This pretreatment method has a beneficial effect on subsequent grinding and leaching. That is, the macroscopic structure of the ore is first changed to make more defects (microcracks) appear inside the ore, the grinding resistance is small, the difficulty is low, the ore powder obtained is finer, and more reactive sites appear inside the ore, which is beneficial to the subsequent reaction, leaching, and separation of valuable metals and media. Compared with conventional heating, microwave heating not only has the characteristics of rapid heating and can increase the reaction rate of the reduction process, but also can pretreat the ore without adding a reducing agent and crushing the original ore, that is, without forming an alloy, the in-situ gas phase components in the mineral phase diffuse along the pores, cracks, and phase interfaces in the original ore, making the original ore structure loose, which is conducive to subsequent processing.

[0039] 2. Microwaves can enhance the leaching of manganese, and achieve efficient leaching of copper, nickel and cobalt on the basis of efficient dissociation and reconstruction of the mineral phase structure of polymetallic nodules. At the same leaching amount, the amount of ore can be reduced by 25% and the amount of acid / alkali can be reduced by more than 10%. Under the same amount of ore and acid / alkali, the recovery rate of manganese under microwave heating is increased by more than 19% compared with conventional heating. The electromagnetic radiation of microwaves intensifies the turbulent flow of the solution to a certain extent, and accelerates the process of redox reaction to a certain extent.

[0040] 3. More sulfides will be produced during the sulfidation roasting process, and more S and MnS will appear under the conventional heating system. The further oxidation reaction of sulfur element is difficult to proceed under the conventional heating system, and the hydrophobicity of sulfur element and low-valent sulfides affects the reduction reaction. Microwave heating can effectively alleviate the formation of sulfur element, promote the redox reaction of low-valent sulfur, and thus greatly improve the manganese leaching efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 The present invention is a schematic diagram of the process of using microwaves to treat manganese nodules. DETAILED DESCRIPTION

[0042] The technical scheme of the present invention is clearly and completely described below in conjunction with the embodiments and the accompanying drawings. It should be pointed out that the embodiments described in the present invention are only used to further explain and illustrate, rather than to limit the scope of application. Based on the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the protection scope of the present invention.

[0043] In the embodiment, steps (2) and (3) initially use commercially available high-grade matte, i.e., pre-purchased copper smelting matte raw material, which has a grade of 73% and main components of 60% Cu, 13% Fe, and 25% S. After continuous production, the high-grade matte obtained by the second-stage blowing in step (6) can be used to replace the commercially available matte for steps (2) and (3).

[0044] The process of microwave treatment of manganese nodules in the present invention is as follows: Figure 1 shown.

[0045] The microwave processing equipment used in the present invention is a Kejing experimental microwave box furnace KSL-1400W-MW.

[0046] Example 1 The main components of the deep-sea manganese nodules in this example include MnO 2 (25.9%)、SiO 2 (16.3%), Fe 2 O 3 (7.6%)、Al 2 O 3 (4.3%), MgO (3.7%), CaO (4.5%), Na 2 O (1.2%), NiO (1.1%), CuO (1.1%), Co 2 O 3 (0.19%).

[0047] (1) Microwave preheating activation: 100 g of deep-sea manganese nodule ore was preheated and activated by microwaves at a microwave power of 300 W and a frequency of 2.3 GHz. The ore temperature was heated to 300 °C by microwaves. The microwave power was adjusted while the microwave frequency was kept constant. The ore was kept at 300 °C for 30 min to obtain activated manganese nodules. (2) Grinding and premixing: Grind the activated manganese nodules to obtain ore powder of about 0.8 mm. Take 100 g of deep-sea manganese nodule ore powder and mix it with 30 g of reducing agent high-grade matte to obtain premixed activated ore powder; (3) Microwave reduction acid leaching: under microwave environment, sulfuric acid as leaching agent and high-grade matte as reducing agent were added to the premixed activated ore powder for reduction activation leaching. The microwave power was 100W and the frequency was 2.3GHz. After the leaching system temperature was set to 60℃ by microwave heating, the microwave power was adjusted while the microwave frequency was kept constant. The leaching was carried out at this temperature for 30min. Each 1g of premixed activated ore powder corresponded to 7mL of acid leaching solution. The concentration of sulfuric acid was 0.6mol / L. A microwave acid leaching solution containing Mn, Co, Ni, Cu, Fe ions and an acid leaching residue containing Fe were obtained. The microwave acid leaching solution also contained impurities. In addition to compounds containing Mn, Co, Ni, Cu, and Fe elements that were not completely leached, the impurities also included compounds containing Si, Al, Mg, Ca, Na and other elements. The Mn recovery rate in the microwave acid leaching solution was 92.5%, the Fe recovery rate was 8.5%, and the recovery rates of other valuable metals Ni, Cu, and Co were approximately 85.5%, 87.6%, and 86.9%, respectively. (4) Sulfide precipitation: Add water to the microwave acid leaching solution to make it 1000 mL, and add 30 g of sodium sulfite Na 2 SO 3 , forming a sulfidation system; using NaOH as a pH regulator, adjusting the pH of the sulfidation system to 2. The sulfidation reaction time is 30 minutes, so that Fe, Co, Cu, Ni ions and a small amount of Mn ions form sulfidation precipitation, and sulfidation demanganization slag containing sulfidation precipitation and manganese-rich sulfidation liquid containing a large amount of Mn ions are obtained; impurities in the microwave acid leaching solution are also precipitated into the sulfidation demanganization slag, becoming impurities in the sulfidation demanganization slag; the sulfidation demanganization slag is filtered and dried for use, and the recovery rates of Fe, Co, Cu, and Ni are approximately 94.5%, 94.7%, 95.1%, and 95.4%, respectively; (5) Microwave sulfidation smelting: add 68g of reducing agent carbon powder and sulfiding agent CaSO 4 The amount is 62g, and a smelting system is formed for smelting. The smelting system is quickly heated to 1100°C by microwave heating with a power of 900W and a frequency of 2.45GHz. After reaching the smelting temperature, the microwave frequency is kept unchanged and the microwave power is adjusted to keep the smelting system at this temperature for 60 minutes, so that the copper, nickel, cobalt, a small amount of Mn and a small part of iron in the sulfidation demanganization slag are sulfided to form a low-grade matte phase (grade 40%), and most of the iron and impurities in the sulfidation demanganization slag enter the slag phase to form sulfidation smelting slag; (6) Oxygen-enriched blowing: Use an oxygen lance to perform a first-stage blowing on the low-grade matte and sulfide smelting slag, with an oxygen pressure of 200 kPa, an oxygen enrichment concentration of 50%, and a blowing time of 60 min. Separate the first-stage blowing slag and perform a second-stage blowing with an oxygen pressure of 150 kPa and an oxygen enrichment concentration of 40%. When the matte grade reaches 60%, the second-stage blowing ends to obtain high-grade matte. Return the second-stage blowing slag to step (5) for microwave sulfide smelting for recycling. The Fe recovery rate of the first-stage blowing slag in the oxygen-enriched blowing step is about 92.7%; (7) Microwave roasting and oxygen pressure leaching: The high-grade matte was roasted and desulfurized by microwave heating. The microwave power was 500 W and the frequency was 2.4 GHz. The temperature of the high-grade matte was 500 °C. The microwave power was adjusted while the microwave frequency was kept constant. The mixture was kept at this temperature for 30 min. After the roasting, the roasted product was added to the reactor. Under the pressure of pure oxygen of 100 kPa, 7 mL of leaching agent was used for every 1 g of the roasted product. 0.6 mol / L sulfuric acid was used as the leaching agent. The oxygen pressure leaching system was quickly heated to 160 °C by microwave heating with a power of 100 W and a frequency of 2.3 GHz. The microwave power was adjusted while the microwave frequency was kept constant. The mixture was kept at this temperature for 60 min. After the leaching, the oxygen pressure leaching solution and oxygen pressure leaching residue were obtained by solid-liquid separation. The recovery rates of Co, Cu and Ni in the oxygen pressure leaching solution were 94.6%, 95.1% and 94.7%, respectively. (8) Multi-stage extraction: The oxygen pressure leaching solution is added to a multi-stage extraction device, and manganese is first extracted with P204 to obtain a manganese-containing extract and a manganese-removed raffinate. Then, copper is extracted from the manganese-removed raffinate with Lix984 to obtain a copper-containing extract and a copper-removed raffinate. Then, cobalt is extracted from the copper-removed raffinate with Cyanex272 to obtain a cobalt-containing extract and a cobalt-removed raffinate. Finally, nickel is extracted from the cobalt-removed raffinate with P507 to obtain a nickel-containing extract and a nickel-removed raffinate. During the extraction process, the concentration of the extractant is 10% (sulfonated kerosene is used as the diluent), the ratio of the extraction phase to the stripping phase is 0.5, the mixing time is 5 min, the phase separation time is 5 min, the extraction and stripping stages are 3, and sulfuric acid with a concentration of 6% is used as the stripping agent. The extraction rates of Ni, Co, Cu, and Mn are 97.5%, 98.3%, 97.8%, and 98.5%, respectively.

[0048] Example 2 The main components of the deep-sea manganese nodules in this example include MnO 2 (33.6%)、SiO 2 (14.7%), Fe 2 O 3 (6.7%)、Al 2 O 3 (4.5%), MgO (3.4%), CaO (3.5%), Na 2 O (1.3%), NiO (1.3%), CuO (1.1%), Co2 O 3 (0.21%).

[0049] (1) Microwave preheating activation: 100 g of deep-sea manganese nodule ore was preheated and activated by microwaves at a microwave power of 350 W and a frequency of 2.4 GHz. The ore temperature was heated to 350°C by microwaves. The microwave power was adjusted while the microwave frequency was kept constant. The ore was kept at 350°C for 28 min to obtain activated manganese nodules. (2) Grinding and premixing: Grind the activated manganese nodules to obtain ore powder of about 0.8 mm. Take 100 g of deep-sea manganese nodule ore powder and mix it with 40 g of high-grade reducing agent matte to obtain premixed activated ore powder; (3) Microwave reduction acid leaching: under microwave environment, sulfuric acid as leaching agent and high-grade matte as reducing agent were added to the premixed activated ore powder for reduction activation leaching. The microwave power was 120W and the frequency was 2.35GHz. After the leaching system temperature was 70℃ by microwave heating, the microwave power was adjusted while the microwave frequency was kept constant. The leaching was carried out at this temperature for 40min. Each 1g of premixed activated ore powder corresponded to 8mL of acid leaching solution. The concentration of sulfuric acid was 0.8mol / L. A microwave acid leaching solution containing Mn, Co, Ni, Cu, Fe ions and an acid leaching residue containing Fe were obtained. The microwave acid leaching solution also contained impurities. In addition to compounds containing Mn, Co, Ni, Cu, and Fe elements that were not completely leached, the impurities also included compounds containing Si, Al, Mg, Ca, Na and other elements. The Mn recovery rate in the microwave acid leaching solution was 93.7%, the Fe recovery rate was 8.2%, and the recovery rates of other valuable metals Ni, Cu, and Co were approximately 86.4%, 88.2%, and 87.4%, respectively. (4) Sulfidation precipitation: Add water to the microwave acid leaching solution to make the volume 1000 mL, and add 38 g of NaHS to form a sulfidation system; use NH 3 ·H 2 O was used as a pH regulator to adjust the pH of the sulfidation system to 2.5. The sulfidation reaction time was 40 minutes, and Fe, Co, Cu, Ni ions and a small amount of Mn ions formed sulfidation precipitation, and sulfidation demanganization slag containing sulfidation precipitation and manganese-rich sulfidation liquid containing a large amount of Mn ions were obtained; impurities in the microwave acid leaching solution were also precipitated into the sulfidation demanganization slag and became impurities in the sulfidation demanganization slag; the sulfidation demanganization slag was filtered and dried for use, and the recovery rates of Fe, Co, Cu, and Ni were approximately 95.1%, 95.5%, 95.6%, and 95.8%, respectively; (5) Microwave sulfidation smelting: add 72g of reducing agent carbon powder and sulfiding agent CaSO 4The amount is 68g, and a smelting system is formed for smelting. The smelting system is quickly heated to 1200°C by microwave heating with a power of 1000W and a frequency of 2.55GHz. After reaching the smelting temperature, the microwave frequency is kept unchanged and the microwave power is adjusted to keep the smelting system at this temperature for 70 minutes, so that the copper, nickel, cobalt, a small amount of Mn and a small part of iron in the sulfidation demanganization slag are sulfided to form a low-grade matte phase (grade 43%), and most of the iron and impurities in the sulfidation demanganization slag enter the slag phase to form sulfidation smelting slag; (6) Oxygen-enriched blowing: Use an oxygen lance to perform a first-stage blowing on the low-grade matte and sulfide smelting slag, with an oxygen pressure of 210 kPa, an oxygen enrichment concentration of 53%, and a blowing time of 65 min. Separate the first-stage blowing slag and perform a second-stage blowing, with an oxygen pressure of 160 kPa and an oxygen enrichment concentration of 43%. When the matte grade reaches 63%, the second-stage blowing is terminated to obtain high-grade matte. The second-stage blowing slag is returned to step (5) for microwave sulfide smelting for recycling. The Fe recovery rate of the first-stage blowing slag in the oxygen-enriched blowing step is about 93.3%; (7) Microwave roasting and oxygen pressure leaching: The high-grade matte was roasted and desulfurized by microwave heating. The microwave power was 560 W and the frequency was 2.46 GHz. The temperature of the high-grade matte was 550 °C. The microwave power was adjusted while the microwave frequency was kept constant. The product was kept at this temperature for 40 min. After the roasting, the product was added to the reactor. Under the pressure of pure oxygen of 200 kPa, 8 mL of leaching agent was used for every 1 g of the product. 0.8 mol / L sulfuric acid was used as the leaching agent. The oxygen pressure leaching system was quickly heated to 170 °C by microwave heating at a power of 120 W and a frequency of 2.4 GHz. The microwave power was adjusted while the microwave frequency was kept constant. The product was kept at this temperature for 70 min. After the leaching, the oxygen pressure leaching solution and oxygen pressure leaching residue were obtained by solid-liquid separation. The recovery rates of Co, Cu and Ni in the oxygen pressure leaching solution were 95.1%, 95.7% and 95.4%, respectively. (8) Multi-stage extraction: The oxygen pressure leaching solution is added to a multi-stage extraction device, and manganese is first extracted with P204 to obtain a manganese-containing extract and a manganese-removed raffinate. Then, copper is extracted from the manganese-removed raffinate with Lix984 to obtain a copper-containing extract and a copper-removed raffinate. Then, cobalt is extracted from the copper-removed raffinate with Cyanex272 to obtain a cobalt-containing extract and a cobalt-removed raffinate. Finally, nickel is extracted from the cobalt-removed raffinate with P507 to obtain a nickel-containing extract and a nickel-removed raffinate. During the extraction process, the concentration of the extractant is 15% (sulfonated kerosene is used as the diluent), the ratio of the extraction phase to the stripping phase is 1.0, the mixing time is 8 min, the phase separation time is 8 min, the extraction and stripping stages are 5, and sulfuric acid with a concentration of 6% is used as the stripping agent. The extraction rates of Ni, Co, Cu, and Mn are 98.1%, 98.5%, 98.2%, and 98.8%, respectively.

[0050] Example 3 The main components of the deep-sea manganese nodules in this example include MnO 2(35.5%)、SiO 2 (15.8%), Fe 2 O 3 (5.7%)、Al 2 O 3 (3.5%), MgO (2.2%), CaO (4.5%), Na 2 O (1.6%), NiO (1.2%), CuO (1.4%), Co 2 O 3 (0.26%).

[0051] (1) Microwave preheating activation: 100 g of deep-sea manganese nodule ore was preheated and activated by microwaves at a microwave power of 400 W and a frequency of 2.5 GHz. The ore temperature was heated to 400 °C by microwaves. The microwave power was adjusted while the microwave frequency was kept constant. The ore was kept at 400 °C for 26 min to obtain activated manganese nodules. (2) Grinding and premixing: Grind the activated manganese nodules to obtain ore powder of about 0.8 mm. Take 100 g of deep-sea manganese nodule ore powder and mix it with 55 g of high-grade reducing agent matte to obtain premixed activated ore powder; (3) Microwave reduction acid leaching: under microwave environment, sulfuric acid as leaching agent and high-grade matte as reducing agent were added to the premixed activated ore powder for reduction activation leaching. The microwave power was 140W and the frequency was 2.45GHz. After the leaching system temperature was 80℃ by microwave heating, the microwave power was adjusted while the microwave frequency was kept constant. The leaching was carried out at this temperature for 50min. Each 1g of premixed activated ore powder corresponded to 9mL of acid leaching solution. The concentration of sulfuric acid was 1.0mol / L. A microwave acid leaching solution containing Mn, Co, Ni, Cu, Fe ions and an acid leaching residue containing Fe were obtained. The microwave acid leaching solution also contained impurities. In addition to compounds containing Mn, Co, Ni, Cu, and Fe elements that were not completely leached, the impurities also included compounds containing Si, Al, Mg, Ca, Na and other elements. The Mn recovery rate in the microwave acid leaching solution was 94.3%, the Fe recovery rate was 8.0%, and the recovery rates of other valuable metals Ni, Cu, and Co were approximately 86.6%, 88.6%, and 87.9%, respectively. (4) Sulfide precipitation: Add water to the microwave acid leaching solution to make it 1000 mL, and add 46 g Na 2 S, constitutes the vulcanization system; using NH 4Cl was used as a pH regulator to adjust the pH of the sulfidation system to 2.9. The sulfidation reaction time was 50 min, and Fe, Co, Cu, Ni ions and a small amount of Mn ions formed sulfidation precipitation, and sulfidation demanganization slag containing sulfidation precipitation and manganese-rich sulfidation liquid containing a large amount of Mn ions were obtained; impurities in the microwave acid leaching solution were also precipitated into the sulfidation demanganization slag, becoming impurities in the sulfidation demanganization slag; the sulfidation demanganization slag was filtered and dried for standby use, and the recovery rates of Fe, Co, Cu, and Ni were approximately 95.6%, 96.1%, 96.2%, and 96.4%, respectively; (5) Microwave sulfidation smelting: Add 88g of reducing agent carbon powder and sulfiding agent CaSO 4 The amount is 74g, and a smelting system is formed for smelting. The smelting system is quickly heated to 1250°C by microwave heating with a power of 1100W and a frequency of 2.6GHz. After reaching the smelting temperature, the microwave frequency is kept unchanged and the microwave power is adjusted to keep the smelting system at this temperature for 80 minutes, so that the copper, nickel, cobalt, a small amount of Mn and a small part of iron in the sulfidation demanganization slag are sulfided to form a low-grade matte phase (grade 47%), and most of the iron and impurities in the sulfidation demanganization slag enter the slag phase to form sulfidation smelting slag; (6) Oxygen-enriched blowing: Use an oxygen lance to perform a first-stage blowing on the low-grade matte and sulfide smelting slag, with an oxygen pressure of 220 kPa, an oxygen enrichment concentration of 55%, and a blowing time of 75 min. Separate the first-stage blowing slag and perform a second-stage blowing with an oxygen pressure of 170 kPa and an oxygen enrichment concentration of 46%. When the matte grade reaches 65%, the second-stage blowing is terminated to obtain high-grade matte. The second-stage blowing slag is returned to step (5) for microwave sulfide smelting for recycling. The Fe recovery rate of the first-stage blowing slag in the oxygen-enriched blowing step is about 93.7%; (7) Microwave roasting and oxygen pressure leaching: The high-grade matte was roasted and desulfurized by microwave heating. The microwave power was 620 W and the frequency was 2.58 GHz. The temperature of the high-grade matte was 600 °C. The microwave power was adjusted while the microwave frequency was kept constant. The mixture was kept at this temperature for 50 min. After the roasting, the roasted product was added to the reactor. Under the pressure of pure oxygen of 300 kPa, 9 mL of leaching agent was used for every 1 g of the roasted product. 1.0 mol / L sulfuric acid was used as the leaching agent. The oxygen pressure leaching system was quickly heated to 180 °C by microwave heating at a power of 140 W and a frequency of 2.5 GHz. The microwave power was adjusted while the microwave frequency was kept constant. The mixture was kept at this temperature for 80 min. After the leaching, the oxygen pressure leaching solution and oxygen pressure leaching residue were obtained by solid-liquid separation. The recovery rates of Co, Cu and Ni in the oxygen pressure leaching solution were 95.5%, 96.1% and 95.8%, respectively. (8) Multi-stage extraction: The oxygen pressure leaching solution is added to a multi-stage extraction device, and manganese is first extracted with P204 to obtain a manganese-containing extract and a manganese-removed raffinate. Then, copper is extracted from the manganese-removed raffinate with Lix984 to obtain a copper-containing extract and a copper-removed raffinate. Then, cobalt is extracted from the copper-removed raffinate with Cyanex272 to obtain a cobalt-containing extract and a cobalt-removed raffinate. Finally, nickel is extracted from the cobalt-removed raffinate with P507 to obtain a nickel-containing extract and a nickel-removed raffinate. During the extraction process, the concentration of the extractant is 20% (sulfonated kerosene is used as the diluent), the ratio of the extraction phase to the stripping phase is 1.5, the mixing time is 10 min, the phase separation time is 11 min, the extraction and stripping stages are 7, and sulfuric acid with a concentration of 6% is used as the stripping agent. The extraction rates of Ni, Co, Cu, and Mn are 98.4%, 98.7%, 98.4%, and 99.0%, respectively.

[0052] Example 4 The main components of the deep-sea manganese nodules in this example include MnO 2 (37.9%)、SiO 2 (17.3%), Fe 2 O 3 (9.7%)、Al 2 O 3 (3.1%), MgO (1.1%), CaO (1.9%), Na 2 O (1.0%), NiO (1.8%), CuO (1.7%), Co 2 O 3 (0.12%).

[0053] (1) Microwave preheating activation: 100 g of deep-sea manganese nodule ore was preheated and activated by microwaves at a microwave power of 450 W and a frequency of 2.6 GHz. The ore temperature was heated to 400 °C by microwaves. The microwave power was adjusted while the microwave frequency was kept constant. The ore was kept at 400 °C for 26 min to obtain activated manganese nodules. (2) Grinding and premixing: Grind the activated manganese nodules to obtain ore powder of about 0.8 mm. Take 100 g of deep-sea manganese nodule ore powder and mix it with 70 g of reducing agent high-grade matte to obtain premixed activated ore powder; (3) Microwave reduction acid leaching: Under microwave environment, sulfuric acid as a leaching agent and high-grade matte as a reducing agent were added to the premixed activated ore powder for reduction activation leaching. The microwave power was 160W and the frequency was 2.6GHz. After the leaching system temperature was set to 90°C by microwave heating, the microwave power was adjusted while the microwave frequency was kept constant. The leaching was carried out at this temperature for 60 minutes. Each 1g of premixed activated ore powder corresponded to 10mL of acid leaching solution. The concentration of sulfuric acid was 1.2mol / L. A microwave acid leaching solution containing Mn, Co, Ni, Cu, Fe ions and an acid leaching residue containing Fe were obtained. The microwave acid leaching solution also contained impurities. In addition to compounds containing Mn, Co, Ni, Cu, and Fe elements that were not completely leached, the impurities also included compounds containing Si, Al, Mg, Ca, Na and other elements. The Mn recovery rate in the microwave acid leaching solution was 94.8%, the Fe recovery rate was 8.0%, and the recovery rates of other valuable metals Ni, Cu, and Co were approximately 87.2%, 89.1%, and 88.4%, respectively. (4) Sulfide precipitation: Add water to the microwave acid leaching solution to make it 1000 mL, and add 55 g of sodium sulfite Na 2 SO 3 , forming a sulfidation system; using NaOH as a pH regulator, the pH of the sulfidation system was adjusted to 3.3. The sulfidation reaction time was 60 minutes, so that Fe, Co, Cu, Ni ions and a small amount of Mn ions formed sulfidation precipitation, and sulfidation demanganization slag containing sulfidation precipitation and manganese-rich sulfidation liquid containing a large amount of Mn ions were obtained; impurities in the microwave acid leaching solution were also precipitated into the sulfidation demanganization slag, becoming impurities in the sulfidation demanganization slag; the sulfidation demanganization slag was filtered and dried for use, and the recovery rates of Fe, Co, Cu, and Ni were approximately 95.8%, 96.3%, 96.4%, and 96.7%, respectively; (5) Microwave sulfidation smelting: Add 97g of reducing agent carbon powder and sulfiding agent CaSO 4 The amount is 80g, a smelting system is formed for smelting, and the smelting system is quickly heated to 1265°C by microwave heating with a power of 1200W and a frequency of 2.7GHz. After reaching the smelting temperature, the microwave frequency is kept unchanged and the microwave power is adjusted to keep the smelting system at this temperature for 90 minutes, so that the copper, nickel, cobalt, a small amount of Mn and a small part of iron in the sulfidation demanganization slag are sulfided to form a low-grade matte phase (grade 48%), and most of the iron and impurities in the sulfidation demanganization slag enter the slag phase to form sulfidation smelting slag; (6) Oxygen-enriched blowing: Use an oxygen lance to perform a first-stage blowing on the low-grade matte and sulfide smelting slag, with an oxygen pressure of 240 kPa, an oxygen enrichment concentration of 57%, and a blowing time of 90 min. Separate the first-stage blowing slag and perform a second-stage blowing with an oxygen pressure of 180 kPa and an oxygen enrichment concentration of 48%. When the matte grade reaches 67%, the second-stage blowing is terminated to obtain high-grade matte. The second-stage blowing slag is returned to step (5) for microwave sulfide smelting for recycling. The Fe recovery rate of the first-stage blowing slag in the oxygen-enriched blowing step is about 94.4%. (7) Microwave roasting and oxygen pressure leaching: The high-grade matte was roasted and desulfurized by microwave heating. The microwave power was 700 W and the frequency was 2.7 GHz. The temperature of the high-grade matte was 700 °C. The microwave power was adjusted while the microwave frequency was kept constant. The product was kept at this temperature for 70 min. After the roasting, the product was added to the reactor. Under the pressure of pure oxygen of 400 kPa, 10 mL of leaching agent was used for every 1 g of the product. 1.2 mol / L sulfuric acid was used as the leaching agent. The oxygen pressure leaching system was quickly heated to 190 °C by microwave heating at a power of 160 W and a frequency of 2.6 GHz. The microwave power was adjusted while the microwave frequency was kept constant. The product was kept at this temperature for 100 min. After the leaching, the oxygen pressure leaching solution and oxygen pressure leaching residue were obtained by solid-liquid separation. The recovery rates of Co, Cu and Ni in the oxygen pressure leaching solution were 96.3%, 96.8% and 96.5%, respectively. (8) Multi-stage extraction: The oxygen pressure leaching solution was added to a multi-stage extraction device, and manganese was first extracted with P204 to obtain a manganese-containing extract and a manganese-removed raffinate. Then, copper was extracted from the manganese-removed raffinate with Lix984 to obtain a copper-containing extract and a copper-removed raffinate. Then, cobalt was extracted from the copper-removed raffinate with Cyanex272 to obtain a cobalt-containing extract and a cobalt-removed raffinate. Finally, nickel was extracted from the cobalt-removed raffinate with P507 to obtain a nickel-containing extract and a nickel-removed raffinate. During the extraction process, the concentration of the extractant was 25% (sulfonated kerosene was used as the diluent), the ratio of the extraction phase to the stripping phase was 2.0, the mixing time was 12 min, the phase separation time was 13 min, the extraction and stripping stages were 9, and sulfuric acid with a concentration of 6% was used as the stripping agent. The extraction rates of Ni, Co, Cu, and Mn were 98.7%, 99.0%, 98.7%, and 99.3%, respectively.

[0054] Example 5 The main components of the deep-sea manganese nodules in this example include MnO 2 (39.5%)、SiO 2 (18.8%), Fe 2 O 3 (5.1%)、Al 2 O 3 (4.7%), MgO (1.7%), CaO (3.0%), Na 2 O (1.6%), NiO (1.1%), CuO (1.1%), Co2 O 3 (0.22%).

[0055] (1) Microwave preheating activation: 100 g of deep-sea manganese nodule ore was preheated and activated by microwaves at a microwave power of 500 W and a frequency of 2.75 GHz. The ore temperature was heated to 480 °C by microwaves. The microwave power was adjusted while the microwave frequency was kept constant. The ore was kept at 480 °C for 30 min to obtain activated manganese nodules. (2) Grinding and premixing: Grind the activated manganese nodules to obtain ore powder of about 0.8 mm. Take 100 g of deep-sea manganese nodule ore powder and mix it with 90 g of high-grade matte as a reducing agent to obtain premixed activated ore powder; (3) Microwave reduction acid leaching: under microwave environment, sulfuric acid as leaching agent and high-grade matte as reducing agent were added to the premixed activated ore powder for reduction activation leaching. The microwave power was 180W and the frequency was 2.7GHz. After the leaching system temperature was set to 95℃ by microwave heating, the microwave power was adjusted while the microwave frequency was kept constant. The leaching was carried out at this temperature for 60min. Each 1g of premixed activated ore powder corresponded to 10mL of acid leaching solution. The concentration of sulfuric acid was 1.4mol / L. A microwave acid leaching solution containing Mn, Co, Ni, Cu, Fe ions and an acid leaching residue containing Fe were obtained. The microwave acid leaching solution also contained impurities. In addition to compounds containing Mn, Co, Ni, Cu, and Fe elements that were not completely leached, the impurities also included compounds containing Si, Al, Mg, Ca, Na and other elements. The Mn recovery rate in the microwave acid leaching solution was 95.1%, the Fe recovery rate was 7.7%, and the recovery rates of other valuable metals Ni, Cu, and Co were approximately 87.5%, 89.6%, and 88.7%, respectively. (4) Sulfide precipitation: Add water to the microwave acid leaching solution to make it 1000 mL, and add 68 g of sodium sulfite Na 2 SO 3 , forming a sulfidation system; using NaOH as a pH regulator, the pH of the sulfidation system was adjusted to 3.9. The sulfidation reaction time was 60 minutes, so that Fe, Co, Cu, Ni ions and a small amount of Mn ions formed sulfidation precipitation, and sulfidation demanganization slag containing sulfidation precipitation and manganese-rich sulfidation liquid containing a large amount of Mn ions were obtained; impurities in the microwave acid leaching solution were also precipitated into the sulfidation demanganization slag, becoming impurities in the sulfidation demanganization slag; the sulfidation demanganization slag was filtered and dried for use, and the recovery rates of Fe, Co, Cu, and Ni were approximately 96.1%, 96.6%, 96.7%, and 97.0%, respectively; (5) Microwave sulfidation smelting: Add 105g of reducing agent carbon powder and sulfiding agent CaSO 4The amount is 80g, a smelting system is formed for smelting, and the smelting system is quickly heated to 1300°C by microwave heating with a power of 1300W and a frequency of 2.8GHz. After reaching the smelting temperature, the microwave frequency is kept unchanged and the microwave power is adjusted to keep the smelting system at this temperature for 100 minutes, so that the copper, nickel, cobalt, a small amount of Mn and a small part of iron in the sulfidation demanganization slag are sulfided to form a low-grade matte phase (grade 50%), and most of the iron and impurities in the sulfidation demanganization slag enter the slag phase to form sulfidation smelting slag; (6) Oxygen-enriched blowing: Use an oxygen lance to perform a first-stage blowing on the low-grade matte and sulfide smelting slag, with an oxygen pressure of 250 kPa, an oxygen enrichment concentration of 60%, and a blowing time of 100 min. Separate the first-stage blowing slag and perform a second-stage blowing with an oxygen pressure of 190 kPa and an oxygen enrichment concentration of 50%. When the matte grade reaches 70%, the second-stage blowing is terminated to obtain high-grade matte. The second-stage blowing slag is returned to step (5) for microwave sulfide smelting for recycling. The Fe recovery rate of the first-stage blowing slag in the oxygen-enriched blowing step is about 94.9%; (7) Microwave roasting and oxygen pressure leaching: The high-grade matte was roasted and desulfurized by microwave heating, with a microwave power of 750 W and a frequency of 2.75 GHz, so that the temperature of the high-grade matte was 750 °C. The microwave power was adjusted while the microwave frequency was kept constant, and the temperature was kept at this temperature for 90 min. After the roasting, the roasted product was added to the reactor, and 10 mL of leaching agent was used for every 1 g of roasted product under a pure oxygen pressure of 550 kPa. 1.4 mol / L sulfuric acid was used as the leaching agent. The oxygen pressure leaching system was quickly heated to 200 °C by microwave heating with a power of 160 W and a frequency of 2.6 GHz. The microwave power was adjusted while the microwave frequency was kept constant, and the temperature was kept at this temperature for 120 min. After the leaching, the oxygen pressure leaching solution and oxygen pressure leaching residue were obtained by solid-liquid separation. The recovery rates of Co, Cu and Ni in the oxygen pressure leaching solution were 96.7%, 97.2% and 96.9%, respectively. (8) Multi-stage extraction: The oxygen pressure leaching solution is added to a multi-stage extraction device, and manganese is first extracted with P204 to obtain a manganese-containing extract and a manganese-removed raffinate. Then, copper is extracted from the manganese-removed raffinate with Lix984 to obtain a copper-containing extract and a copper-removed raffinate. Then, cobalt is extracted from the copper-removed raffinate with Cyanex272 to obtain a cobalt-containing extract and a cobalt-removed raffinate. Finally, nickel is extracted from the cobalt-removed raffinate with P507 to obtain a nickel-containing extract and a nickel-removed raffinate. During the extraction process, the concentration of the extractant is 30% (sulfonated kerosene is used as the diluent), the ratio of the extraction phase to the stripping phase is 2.5, the mixing time is 15 min, the phase separation time is 15 min, the extraction and stripping stages are 9, and sulfuric acid with a concentration of 6% is used as the stripping agent. The extraction rates of Ni, Co, Cu, and Mn are 98.9%, 99.2%, 98.9%, and 99.5%, respectively.

[0056] Example 6 The main components of the deep-sea manganese nodules in this example include MnO2 (39.7%)、SiO 2 (15.7%), Fe 2 O 3 (6.8%)、Al 2 O 3 (5.9%), MgO (4.2%), CaO (4.7%), Na 2 O (2.2%), NiO (2.6%), CuO (1.9%), Co 2 O 3 (0.27%).

[0057] (1) Microwave preheating activation: 100 g of deep-sea manganese nodule ore was preheated and activated by microwaves at a microwave power of 500 W and a frequency of 2.8 GHz. The ore temperature was heated to 500 °C by microwaves. The microwave power was adjusted while the microwave frequency was kept constant. The ore was kept at 500 °C for 30 min to obtain activated manganese nodules. (2) Grinding and premixing: Grind the activated manganese nodules to obtain ore powder of about 0.8 mm. Take 100 g of deep-sea manganese nodule ore powder and mix it with 100 g of high-grade reducing agent matte to obtain premixed activated ore powder; (3) Microwave reduction acid leaching: Under microwave environment, sulfuric acid as a leaching agent and high-grade matte as a reducing agent were added to the premixed activated ore powder for reduction activation leaching. The microwave power was 200 W and the frequency was 2.8 GHz. After the leaching system temperature was set to 100 °C by microwave heating, the microwave power was adjusted while the microwave frequency was kept constant. The leaching was carried out at this temperature for 60 min. Each 1 g of premixed activated ore powder corresponded to 10 mL of acid leaching solution. The concentration of sulfuric acid was 1.6 mol / L. A microwave acid leaching solution containing Mn, Co, Ni, Cu, Fe ions and an acid leaching residue containing Fe were obtained. The microwave acid leaching solution also contained impurities. In addition to compounds containing Mn, Co, Ni, Cu, and Fe elements that were not completely leached, the impurities also included compounds containing Si, Al, Mg, Ca, Na and other elements. The Mn recovery rate in the microwave acid leaching solution was 95.5%, the Fe recovery rate was 7.4%, and the recovery rates of other valuable metals Ni, Cu, and Co were approximately 87.9%, 89.9%, and 89.1%, respectively. (4) Sulfide precipitation: Add water to the microwave acid leaching solution to make it 1000 mL, and add 80 g of sodium sulfite Na 2 SO 3, forming a sulfidation system; using NaOH as a pH regulator, adjusting the pH of the sulfidation system to 5. The sulfidation reaction time is 60 minutes, so that Fe, Co, Cu, Ni ions and a small amount of Mn ions form sulfidation precipitation, and sulfidation demanganization slag containing sulfidation precipitation and manganese-rich sulfidation liquid containing a large amount of Mn ions are obtained; impurities in the microwave acid leaching solution are also precipitated into the sulfidation demanganization slag, becoming impurities in the sulfidation demanganization slag; the sulfidation demanganization slag is filtered and dried for use, and the recovery rates of Fe, Co, Cu, and Ni are approximately 96.3%, 96.8%, 96.9%, and 97.3%, respectively; (5) Microwave sulfidation smelting: Add 120g of reducing agent carbon powder and sulfiding agent CaSO 4 The amount is 80g, a smelting system is formed for smelting, and the smelting system is quickly heated to 1300°C by microwave heating with a power of 1300W and a frequency of 2.8GHz. After reaching the smelting temperature, the microwave frequency is kept unchanged and the microwave power is adjusted to keep the smelting system at this temperature for 120 minutes, so that the copper, nickel, cobalt, a small amount of Mn and a small part of iron in the sulfidation demanganization slag are sulfided to form a low-grade matte phase (grade 50%), and most of the iron and impurities in the sulfidation demanganization slag enter the slag phase to form sulfidation smelting slag; (6) Oxygen-enriched blowing: Use an oxygen lance to perform a first-stage blowing on the low-grade matte and sulfide smelting slag, with an oxygen pressure of 250 kPa, an oxygen enrichment concentration of 60%, and a blowing time of 120 min. Separate the first-stage blowing slag and perform a second-stage blowing with an oxygen pressure of 200 kPa and an oxygen enrichment concentration of 50%. When the matte grade reaches 70%, the second-stage blowing is terminated to obtain high-grade matte. The second-stage blowing slag is returned to step (5) for microwave sulfide smelting for recycling. The Fe recovery rate of the first-stage blowing slag in the oxygen-enriched blowing step is about 95.1%. (7) Microwave roasting and oxygen pressure leaching: The high-grade matte was roasted and desulfurized by microwave heating. The microwave power was 800 W and the frequency was 2.8 GHz. The temperature of the high-grade matte was 800 °C. The microwave power was adjusted while the microwave frequency was kept constant. The product was kept at this temperature for 100 min. After the roasting, the product was added to the reactor. Under the pressure of pure oxygen of 600 kPa, 10 mL of leaching agent was used for every 1 g of the product. 1.6 mol / L sulfuric acid was used as the leaching agent. The oxygen pressure leaching system was quickly heated to 200 °C by microwave heating at a power of 200 W and a frequency of 2.8 GHz. The microwave power was adjusted while the microwave frequency was kept constant. The product was kept at this temperature for 150 min. After the leaching, the oxygen pressure leaching solution and oxygen pressure leaching residue were obtained by solid-liquid separation. The recovery rates of Co, Cu and Ni in the oxygen pressure leaching solution were 96.9%, 97.4% and 97.1%, respectively. (8) Multi-stage extraction: The oxygen pressure leaching solution is added to a multi-stage extraction device, and manganese is first extracted with P204 to obtain a manganese-containing extract and a manganese-removed raffinate. Then, copper is extracted from the manganese-removed raffinate with Lix984 to obtain a copper-containing extract and a copper-removed raffinate. Then, cobalt is extracted from the copper-removed raffinate with Cyanex272 to obtain a cobalt-containing extract and a cobalt-removed raffinate. Finally, nickel is extracted from the cobalt-removed raffinate with P507 to obtain a nickel-containing extract and a nickel-removed raffinate. During the extraction process, the concentration of the extractant is 30% (sulfonated kerosene is used as the diluent), the ratio of the extraction phase to the stripping phase is 2.5, the mixing time is 15 min, the phase separation time is 15 min, the extraction and stripping stages are 9, and sulfuric acid with a concentration of 6% is used as the stripping agent. The extraction rates of Ni, Co, Cu, and Mn are 99.0%, 99.3%, 99.0%, and 99.6%, respectively.

[0058] Comparative Example 1 The conditions of microwave treatment in each step were changed, and the remaining steps were the same as those in Example 1.

[0059] The main components of deep-sea manganese nodules in this comparative example include MnO 2 (25.9%)、SiO 2 (16.3%), Fe 2 O 3 (7.6%)、Al 2 O 3 (4.3%), MgO (3.7%), CaO (4.5%), Na 2 O (1.2%), NiO (1.1%), CuO (1.1%), Co 2 O 3 (0.19%).

[0060] (1) Microwave preheating activation: 100 g of deep-sea manganese nodule ore was preheated and activated by microwaves at a microwave power of 100 W and a frequency of 2.0 GHz. The ore temperature was heated to 200 °C by microwaves. The microwave frequency was kept constant and the microwave power was adjusted. The ore was kept at 200 °C for 15 min to obtain activated manganese nodules. (2) Grinding and premixing: Grind the activated manganese nodules to obtain ore powder of about 0.8 mm. Take 100 g of deep-sea manganese nodule ore powder and mix it with 30 g of reducing agent high-grade matte to obtain premixed activated ore powder; (3) Microwave reduction acid leaching: under microwave environment, sulfuric acid as leaching agent and high-grade matte as reducing agent were added to the premixed activated ore powder for reduction activation leaching. The microwave power was 90W and the frequency was 2.0GHz. After the leaching system temperature was 50℃ by microwave heating, the microwave power was adjusted while the microwave frequency was kept constant. The leaching was carried out at this temperature for 20min. Each 1g of premixed activated ore powder corresponded to 7mL of acid leaching solution. The concentration of sulfuric acid was 0.6mol / L. A microwave acid leaching solution containing Mn, Co, Ni, Cu, Fe ions and an acid leaching residue containing Fe were obtained. The microwave acid leaching solution also contained impurities. In addition to compounds containing Mn, Co, Ni, Cu, and Fe elements that were not completely leached, the impurities also included compounds containing Si, Al, Mg, Ca, Na and other elements. The Mn recovery rate in the microwave acid leaching solution was 75.7%, the Fe recovery rate was 9.4%, and the recovery rates of other valuable metals Ni, Cu, and Co were approximately 74.3%, 74.1%, and 74.5%, respectively. (4) Sulfide precipitation: Add water to the microwave acid leaching solution to make it 1000 mL, and add 30 g of sodium sulfite Na 2 SO 3 , forming a sulfidation system; using citric acid as a pH regulator, adjusting the pH of the sulfidation system to 2. The sulfidation reaction time is 30 minutes, so that Fe, Co, Cu, Ni ions and a small amount of Mn ions form sulfidation precipitation, and sulfidation demanganization slag containing sulfidation precipitation and manganese-rich sulfidation liquid containing a large amount of Mn ions are obtained; impurities in the microwave acid leaching solution are also precipitated into the sulfidation demanganization slag, becoming impurities in the sulfidation demanganization slag; the sulfidation demanganization slag is filtered and dried for use, and the recovery rates of Fe, Co, Cu, and Ni are approximately 76.4%, 76.8%, 76.4%, and 77.1%, respectively; (5) Microwave sulfidation smelting: add 68g of reducing agent carbon powder and sulfiding agent CaSO 4 The amount is 62g, and a smelting system is formed for smelting. The smelting system is quickly heated to 1000°C by microwave heating with a power of 700W and a frequency of 2.2GHz. After reaching the smelting temperature, the microwave frequency is kept unchanged and the microwave power is adjusted to keep the smelting system at this temperature for 50 minutes, so that the copper, nickel, cobalt, a small amount of Mn and a small part of iron in the sulfidation demanganization slag are sulfided to form a low-grade matte phase (grade 30%), and most of the iron and impurities in the sulfidation demanganization slag enter the slag phase to form sulfidation smelting slag; (6) Oxygen-enriched blowing: Use an oxygen lance to perform a first-stage blowing on the low-grade matte and sulfide smelting slag, with an oxygen pressure of 200 kPa, an oxygen enrichment concentration of 50%, and a blowing time of 60 min. Separate the first-stage blowing slag and perform a second-stage blowing with an oxygen pressure of 150 kPa and an oxygen enrichment concentration of 40%. When the matte grade reaches 60%, the second-stage blowing is terminated to obtain high-grade matte. The second-stage blowing slag is returned to step (5) for microwave sulfide smelting for recycling. The Fe recovery rate of the first-stage blowing slag in the oxygen-enriched blowing step is about 75.3%; (7) Microwave roasting and oxygen pressure leaching: The high-grade matte was roasted and desulfurized by microwave heating. The microwave power was 400 W and the frequency was 2.2 GHz. The temperature of the high-grade matte was 400 °C. The microwave power was adjusted while the microwave frequency was kept constant. The product was kept at this temperature for 20 min. After the roasting, the product was added to the reactor. Under the pressure of pure oxygen of 100 kPa, 7 mL of leaching agent was used for every 1 g of the product. 0.6 mol / L of sulfuric acid was used as the leaching agent. The oxygen pressure leaching system was quickly heated to 150 °C by microwave heating at a power of 90 W and a frequency of 2.0 GHz. The microwave power was adjusted while the microwave frequency was kept constant. The product was kept at this temperature for 60 min. After the leaching, the oxygen pressure leaching solution and oxygen pressure leaching residue were obtained by solid-liquid separation. The recovery rates of Co, Cu and Ni in the oxygen pressure leaching solution were 77.7%, 78.6% and 79.0%, respectively. (8) Multi-stage extraction: The oxygen pressure leaching solution was added to a multi-stage extraction device, and manganese was first extracted with P204 to obtain a manganese-containing extract and a manganese-removed raffinate. Then, copper was extracted from the manganese-removed raffinate with Lix984 to obtain a copper-containing extract and a copper-removed raffinate. Then, cobalt was extracted from the copper-removed raffinate with Cyanex272 to obtain a cobalt-containing extract and a cobalt-removed raffinate. Finally, nickel was extracted from the cobalt-removed raffinate with P507 to obtain a nickel-containing extract and a nickel-removed raffinate. During the extraction process, the concentration of the extractant was 10% (sulfonated kerosene was used as the diluent), the ratio of the extraction phase to the stripping phase was 0.5, the mixing time was 5 min, the phase separation time was 5 min, the extraction and stripping stages were 3, and sulfuric acid with a concentration of 6% was used as the stripping agent. The extraction rates of Ni, Co, Cu, and Mn were 79.0%, 78.3%, 79.2%, and 79.3%, respectively.

[0061] Comparative Example 2 Microwaves were not used in any of the steps, and only conventional methods were used to treat deep-sea manganese nodules. The remaining steps were the same as those in Example 6.

[0062] The main components of deep-sea manganese nodules in this comparative example include MnO 2 (39.7%)、SiO 2 (15.7%), Fe 2 O 3 (6.8%)、Al 2 O 3(5.9%), MgO (4.2%), CaO (4.7%), Na 2 O (2.2%), NiO (2.6%), CuO (1.9%), Co 2 O 3 (0.27%).

[0063] (1) No microwave preheating activation treatment; (2) Grinding and premixing: Grind the manganese nodules to obtain ore powder of about 0.8 mm, take 100 g of deep-sea manganese nodule ore powder, and mix it with 100 g of reducing agent high-grade matte to obtain premixed ore powder; (3) Reduction acid leaching: add sulfuric acid as a leaching agent and high-grade matte as a reducing agent to the premixed ore powder for reduction activation leaching; 10 mL of acid leaching solution corresponds to 1 g of premixed ore powder; the concentration of sulfuric acid is 1.6 mol / L; an acid leaching solution containing Mn, Co, Ni, Cu, Fe and other ions and an acid leaching residue containing Fe are obtained; the acid leaching solution also contains impurities, which include compounds containing Si, Al, Mg, Ca, Na and other elements in addition to compounds containing Mn, Co, Ni, Cu and Fe that have not been completely leached; the Mn recovery rate in the acid leaching solution is 75.4%, the Fe recovery rate is 10.4%, and the recovery rates of other valuable metals Ni, Cu and Co are approximately 67.6%, 69.3% and 68.2%, respectively; (4) Sulfide precipitation: Add water to the acid leaching solution to make it 1000 mL, and add 80 g of sodium sulfite Na 2 SO 3 , forming a sulfidation system; using NaOH as a pH regulator, adjusting the pH of the sulfidation system to 5. The sulfidation reaction time is 60 minutes, so that Fe, Co, Cu, Ni ions and a small amount of Mn ions form sulfidation precipitation, and obtain sulfidation demanganization slag containing sulfidation precipitation and manganese-rich sulfidation liquid containing a large amount of Mn ions; impurities in the acid leaching solution are also precipitated into the sulfidation demanganization slag, becoming impurities in the sulfidation demanganization slag; the sulfidation demanganization slag is filtered and dried for use, and the recovery rates of Fe, Co, Cu, and Ni are approximately 66.1%, 66.5%, 66.3%, and 67.5%, respectively; (5) Sulfidation smelting: Add 120g of reducing agent carbon powder and sulfiding agent CaSO 4 The amount is 80g, and a smelting system is formed for smelting. The temperature of the muffle furnace is quickly raised to 1300°C, and the smelting system is kept at this temperature for 120 minutes, so that the copper, nickel, cobalt, a small amount of Mn and a small part of iron in the sulfidation demanganization slag are sulfided to form a low-grade matte phase (grade 50%), and most of the iron and impurities in the sulfidation demanganization slag enter the slag phase to form sulfidation smelting slag; (6) Oxygen-enriched blowing: Use an oxygen lance to perform a first-stage blowing on the low-grade matte and sulfide smelting slag, with an oxygen pressure of 250 kPa, an oxygen enrichment concentration of 60%, and a blowing time of 120 min. Separate the first-stage blowing slag and perform a second-stage blowing with an oxygen pressure of 200 kPa and an oxygen enrichment concentration of 50%. When the matte grade reaches 70%, the second-stage blowing is terminated to obtain high-grade matte. The second-stage blowing slag is returned to step (5) for recycling in sulfide smelting. The Fe recovery rate of the first-stage blowing slag in the oxygen-enriched blowing step is about 65.3%; (7) Oxygen pressure leaching: high-grade matte was added into the reactor, and 10 mL of leaching agent was used for every gram of high-grade matte under the pressure of pure oxygen of 600 kPa, and 1.6 mol / L sulfuric acid was used as the leaching agent. The temperature was raised to 200 °C in a resistance furnace, and the leaching was carried out at this temperature for 150 min. After the leaching was completed, the oxygen pressure leaching liquid and oxygen pressure leaching residue were obtained by solid-liquid separation. The recovery rates of Co, Cu and Ni in the oxygen pressure leaching liquid were 76.7%, 77.4% and 77.5%, respectively. (8) Multi-stage extraction: The oxygen pressure leaching solution was added to a multi-stage extraction device, and manganese was first extracted with P204 to obtain a manganese-containing extract and a manganese-removed raffinate. Then, copper was extracted from the manganese-removed raffinate with Lix984 to obtain a copper-containing extract and a copper-removed raffinate. Then, cobalt was extracted from the copper-removed raffinate with Cyanex272 to obtain a cobalt-containing extract and a cobalt-removed raffinate. Finally, nickel was extracted from the cobalt-removed raffinate with P507 to obtain a nickel-containing extract and a nickel-removed raffinate. During the extraction process, the concentration of the extractant was 30% (sulfonated kerosene was used as the diluent), the ratio of the extraction phase to the stripping phase was 2.5, the mixing time was 15 min, the phase separation time was 15 min, the extraction and stripping stages were 9, and sulfuric acid with a concentration of 6% was used as the stripping agent. The extraction rates of Ni, Co, Cu, and Mn were 76.2%, 77.3%, 78.1%, and 79.9%, respectively.

Claims

1. A method for treating manganese nodules with microwaves, characterized in that: Includes the following: (1) Microwave preheating activation: The manganese nodule ore is preheated and activated by microwaves, so that the structure of manganese agglomerates in the ore is destroyed, and the gas phase components in the ore overflow to obtain activated manganese nodules; (2) Grinding and premixing: Grinding the activated manganese nodules prepared in step (1) to obtain activated manganese nodule ore powder, adding a reducing agent, high-grade matte, to the activated manganese nodule ore powder and mixing to obtain a premixed activated ore powder; (3) Microwave reduction acid leaching: under a microwave environment, sulfuric acid as a leaching agent and high-grade matte as a reducing agent are added to the premixed activated ore powder obtained in step (2) to form a leaching system for reduction activation leaching to obtain a microwave acid leaching solution containing Mn, Co, Ni, Cu, Fe ions and impurities and Fe-containing acid leaching residue; Reduction activation leaching causes the MnO2 and Co2O3 mineral phases in the ore powder to be dissociated and reconstructed into soluble MnSO4 and CoSO4. At the same time, the free CuO and NiO minerals are converted into copper sulfate and nickel sulfate by sulfuric acid leaching; (4) Sulfidation precipitation: adding a sulfidation precipitant to the microwave acid leaching solution obtained in step (3) to form a sulfidation system, wherein Fe, Co, Cu, Ni and part of the Mn ions in the sulfidation system form sulfidation precipitates, thereby obtaining a sulfidation demanganeseized slag containing sulfidation precipitates and impurities and a manganese-rich sulfidation solution mainly containing Mn ions; (5) Microwave sulfidation smelting: adding a reducing agent and a sulfiding agent to the sulfidation demanganization slag obtained in step (4) under a microwave environment to form a smelting system for sulfidation smelting to obtain low-grade matte and sulfidation smelting slag; Among them, low-grade matte is mainly formed by the sulfidation of Cu, Ni, Co, part of Mn and part of Fe in the sulfidation demanganese slag; sulfidation smelting slag is mainly formed by part of the iron and impurities in the sulfidation demanganese slag entering the slag phase; (6) Oxygen-enriched blowing: the low-grade matte and sulfide smelting slag obtained in step (5) are subjected to a first-stage blowing, and after the first-stage blowing slag is separated, a second-stage blowing is continued, and after the second-stage blowing slag is separated, a high-grade matte is obtained; (7) Microwave roasting and oxygen pressure leaching: roasting and desulfurizing the high-grade matte obtained in step (6) by microwave heating to obtain a roasting product; performing oxygen pressure leaching on the roasting product under a microwave environment, and obtaining an oxygen pressure leaching liquid and an oxygen pressure leaching slag by solid-liquid separation after the leaching is completed; (8) Multi-stage extraction: The oxygen pressure leaching solution obtained in step (7) is extracted to separate manganese, copper, nickel and cobalt.

2. The method for microwave treatment of manganese nodules according to claim 1, characterized in that: The specific method of step (1) microwave preheating activation is as follows: using microwave heating with a power of 300W to 500W and a frequency of 2.3GHz to 2.8GHz to make the temperature of the raw ore 300°C to 500°C, adjusting the microwave power while keeping the microwave frequency unchanged, and keeping the temperature at this temperature for 20min to 30min, so that the structure of manganese agglomerates in the raw ore is destroyed and the gas phase components overflow, thereby obtaining activated manganese nodules; The microwave environment in step (3) refers to using microwave heating with a power of 100 W to 200 W and a frequency of 2.3 GHz to 2.8 GHz to make the temperature of the reduction activation leaching system 60° C. to 100° C., then adjusting the microwave power while keeping the microwave frequency unchanged, and maintaining the temperature for 30 min to 60 min to perform reduction activation leaching.

3. The method for microwave treatment of manganese nodules according to claim 1, characterized in that: In step (2), 30 g to 100 g of high-grade matte is added for every 100 g of activated manganese nodule ore powder; In step (3), 30 g to 100 g of high-grade matte is added for every 100 g of premixed activated ore powder, and 7 mL to 10 mL of sulfuric acid is added for every 1 g of premixed activated ore powder, and the concentration of sulfuric acid is 0.6 mol / L to 1.6 mol / L; The grade of the high-grade matte in steps (2) and (3) is 60%-75%, and the main components are as follows: Cu 60%-70%, S 20%-25%, Fe 5%-15%.

4. The method for microwave treatment of manganese nodules according to claim 1, characterized in that: In step (4): The sulfide precipitant includes one or more of H2S, Na2S, NaHS, and Na2SO3; For every 1000mL of microwave acid leaching solution, 30g~80g of sulfide precipitation agent is added, and the sulfide precipitation time is 30min~60min; The pH of the vulcanization system is adjusted to 2-5 by a pH regulator; the pH regulator includes at least one of NaOH, NH3·H2O, NH4Cl, and citric acid.

5. The method for microwave treatment of manganese nodules according to claim 1, characterized in that: In step (5): The microwave environment refers to using microwave heating with a power of 900W to 1300W and a frequency of 2.3GHz to 2.8GHz to make the temperature of the melting system 1100°C to 1300°C, and after reaching the melting temperature, the microwave frequency is kept unchanged and the microwave power is adjusted to keep the melting system at this temperature for 60min to 120min for melting; The grade of the low-grade matte is 40% to 50%; The mass of the mixture of reducing agent and sulfiding agent added to every 100g of sulfiding demanganizing slag is 130g~200g, of which the mass of reducing agent is 68g~120g; The reducing agent is carbon powder, and the vulcanizing agent is CaSO4.

6. The method for microwave treatment of manganese nodules according to claim 1, characterized in that: In step (6): The oxygen pressure of the first stage blowing is 200kPa-250kPa, the oxygen enrichment concentration is 50%-60%, the first stage blowing time is 60min-120min, and when the matte phase grade reaches 50%-60%, the first stage blowing slag is separated and the second stage blowing is continued; The oxygen pressure of the second stage blowing is 150kPa-200kPa, the oxygen enrichment concentration is 40%-50%, the second stage blowing time is 30min-60min, and the blowing end point is when the matte phase grade reaches 60%-75%, that is, high-grade matte is obtained.

7. The method for microwave treatment of manganese nodules according to claim 1, characterized in that: In step (7): The microwave conditions used in roasting and desulfurization are as follows: microwave power 500W~800W, frequency 2.3GHz~2.8GHz, use microwave heating to make the temperature of high-grade matte 500℃~800℃, keep the microwave frequency unchanged and adjust the microwave power, so that the high-grade matte is roasted at this temperature for 30min~120min; The microwave conditions used in oxygen pressure leaching are as follows: first, use microwave heating with a power of 100W to 200W and a frequency of 2.3GHz to 2.8GHz to make the temperature of the oxygen pressure leaching system 160℃ to 200℃, keep the microwave frequency unchanged and adjust the microwave power, so that the leaching system is kept at this temperature for 60min to 150min for oxygen pressure leaching; During oxygen pressure leaching, the pure oxygen pressure is 100kPa~700kPa, sulfuric acid is used as the leaching solution, the sulfuric acid concentration is 0.6mol / L~1.6mol / L, and 7mL~10mL of leaching solution is used for every 1g of roasted product.

8. The method for microwave treatment of manganese nodules according to claim 1, characterized in that: The specific extraction method in step (8) is as follows: First, manganese is extracted from the oxygen pressure leaching solution by using P204 to obtain a manganese-containing extract and a manganese-removed raffinate, and then copper is extracted from the manganese-removed raffinate by using Lix984 to obtain a copper-containing extract and a copper-removed raffinate, and then cobalt is extracted from the copper-removed raffinate by using Cyanex272 to obtain a cobalt-containing extract and a cobalt-removed raffinate, and finally nickel is extracted from the cobalt-removed raffinate by using P507 to obtain a nickel-containing extract and a nickel-removed raffinate; The concentration of the extractant is 10%~30%, sulfonated kerosene is the diluent; the extraction phase ratio is 0.5~2.5, the mixing time is 5min~15min, the phase separation time is 5min~15min, and the extraction level is 3~9; the back extraction uses an aqueous solution of H2SO4 or NaOH.

9. The method for microwave treatment of manganese nodules according to claim 1, characterized in that: The impurities in the microwave acid leaching solution in step (3) include compounds containing Mn, Co, Ni, Cu, and Fe elements that are not completely leached out of the premixed activated ore powder, as well as compounds containing Si, Al, Mg, Ca, and Na elements; The impurities in the sulfidation demanganization slag in step (4) are formed by the impurities in the microwave acid leaching solution in step (3) being precipitated into the sulfidation demanganization slag during the sulfidation precipitation process; The impurities in the sulfidation smelting slag in step (5) are formed by the impurities in the sulfidation demanganization slag in step (4) entering the slag phase during the sulfidation smelting process.

10. The method for microwave treatment of manganese nodules according to claim 1, characterized in that: The Fe-containing acid leaching residue in step (3) is further used to deeply extract the unleached Mn, Co, Ni, Cu, and Fe, or used as cement aggregate or building material; The manganese-rich sulfide liquid obtained in step (4) is distilled to obtain a manganese sulfate product; The high-grade matte obtained in step (6) is returned to step (2) and step (3) for use; the separated second-stage blowing slag is returned to step (5) for microwave sulfidation smelting and recycling; In step (7), the SO2 generated by the roasting desulfurization treatment is absorbed, and the obtained Na2SO3 is recycled as a sulfide precipitant in step (4); the oxygen pressure leaching slag separated after oxygen pressure leaching is deeply purified to separate Mn, Co, Ni, Cu, Fe, or used as cement aggregate or building material.

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