CN-121610640-B - Pretreatment and valuable element extraction method for seabed deep sea polymetallic nodule

Abstract

The invention belongs to the field of mineral resource processing, and in particular relates to a pretreatment and valuable element extraction method of a submarine deep-sea polymetallic nodule, which comprises the steps of carrying out rapid temperature rise and heat preservation pretreatment on a mixed material containing the submarine deep-sea polymetallic nodule, a carbon material and an additive by adopting an electrified resistance heating mode to obtain a pretreated material; the rapid temperature rise rate is 100-500 ℃ per second, the pretreatment temperature is 800-1000 ℃, and the additive comprises at least one of alkali metal salt, alkaline earth metal salt or ammonium salt. According to the invention, instantaneous temperature rising pretreatment is innovatively carried out on the submarine deep-sea polymetallic nodule, the carbon material and the additive, so that the submarine deep-sea polymetallic nodule physical-chemical structure can be optimized, the subsequent leaching behavior is optimized, and the extraction rate of valuable elements is improved.

Inventors

• WANG XU
• YANG CONGREN
• QIN WENQING
• WEN JIE

Assignees

• 中南大学

Dates

Publication Date

20260508

Application Date

20260130

Claims (9)

1. 1. A pretreatment method of a seabed deep sea polymetallic nodule is characterized in that a mixed material containing the seabed deep sea polymetallic nodule, a carbon material and an additive is subjected to rapid temperature rise and heat preservation pretreatment in an electrified resistance heating mode to obtain a pretreated material; the rapid temperature rise rate is 100-500 ℃ per second, the pretreatment temperature is 800-1000 ℃, and the heat preservation pretreatment time is 5-20 seconds; The additive comprises at least one of sodium chloride, potassium chloride, sodium carbonate, potassium carbonate, calcium chloride, magnesium chloride and ammonium chloride.
2. 2. The pretreatment method of the ocean bottom deep sea polymetallic nodule according to claim 1, wherein the ocean bottom deep sea polymetallic nodule comprises 5-50wt% of Mn, 2-20wt% of Fe, more than 0.05 wt% of Cu, more than 0.02 wt% of Ni and more than 0.02 wt% of Co.
3. 3. The method for pretreating a seafloor deep sea polymetallic nodule of claim 1, wherein the carbon material is at least one of graphite powder, activated carbon or carbon black.
4. 4. A method of pre-treating a deep sea multi-metal nodule in the sea according to claim 1, wherein the additive comprises additive a and additive B; the additive A comprises at least one of sodium chloride and potassium chloride; the additive B comprises at least one of sodium carbonate and potassium carbonate; The mass ratio of the additive A to the additive B is 1-4:1-4.
5. 5. The pretreatment method of the ocean bottom deep sea polymetallic nodule according to any one of claims 1 to 4, wherein the weight ratio of the ocean bottom deep sea polymetallic nodule, the carbon material and the additive is 100 (2 to 15): (0.1 to 2).
6. 6. The method for pretreatment of seafloor deep sea polymetallic nodule of claim 1, wherein the energized resistance heating is performed in a graphite flash furnace.
7. 7. A method for extracting valuable elements from ocean bottom deep sea polymetallic nodules is characterized by pretreating the ocean bottom deep sea polymetallic nodules by the pretreatment method of any one of claims 1-6 to obtain pretreated materials, and carrying out acid leaching treatment on the pretreated materials to obtain leaching solutions of the valuable elements.
8. 8. The method for extracting valuable elements from ocean bottom deep sea polymetallic nodule as claimed in claim 7, wherein the acid solution in the acid leaching process comprises aqueous solutions of organic acid and/or inorganic acid; the concentration of hydrogen ions in the acid solution is 0.8-4M.
9. 9. The method for extracting valuable elements from ocean bottom deep sea polymetallic nodule according to claim 7 or 8, wherein the liquid-solid ratio in the acid leaching process is 5-20 mL/g; The acid leaching temperature is 50-100 ℃; The acid leaching time is 30 min-2 h.

Description

Pretreatment and valuable element extraction method for seabed deep sea polymetallic nodule Technical Field The invention belongs to the field of metal mineral resource processing, and particularly relates to the field of extraction of multi-metal nodule valuable elements in the deep sea on the sea bottom. Background The ocean bottom deep sea polymetallic nodule is rich in valuable metal elements such as manganese, iron, copper, nickel, cobalt and the like, and mainly takes a high-valence manganese oxide/hydroxide phase and an iron oxide/hydroxide phase as carriers, and has layered growth of a structure and complex mineral symbiosis. Since manganese exists mainly in the high valence state of Mn (IV)/Mn (III), cu, co, ni, etc. tend to be strongly coupled to the ferromanganese oxide framework phase by adsorption, complexation or the like, making the framework phase a typical refractory phase. If the structure is not damaged by controlled reduction and Mn (IV) is promoted to be converted into Mn (II), valuable metals are difficult to fully release, and conventional leaching is characterized by slow dynamics, high acid consumption, poor selectivity, impurity co-dissolution, heavy subsequent purification burden and the like. For the treatment of multi-metal nodules in the deep sea on the sea floor, the existing industrial and laboratory routes are generally divided into two categories, namely a combined fire-wet process and a pure wet process. The fire-wet combination method is represented by INCO smelting-leaching route, in which the nodule is undergone the processes of reduction roasting and electric furnace smelting to produce ferromanganese-rich slag and alloy containing Cu, ni and Co, after the alloy is sulfurized to form copper matte, the copper matte is leached by sulfuric acid, and matched with extraction/electrolysis/hydrogen reduction to separate metal, and the slag can be further used for ferromanganese alloy production. On the basis, the prior art has the advantages that the alloy wet treatment flow is improved through the steps of iron precipitation, purification and the like, for example, an H 2SO4–H2SO3 system is adopted to realize the selective dissolution of Ni/Co and the precipitation of Cu in a CuS form, so that the flow suitability and the recovery efficiency are improved. The pure wet process usually uses strong acid such as sulfuric acid as medium, and is supplemented with reducing agents such as SO 2, molasses, pyrite and the like to realize reduction and dissolution of Mn (IV), and combines selective precipitation and ion exchange/solvent extraction to complete metal separation, and the prior art also provides high-pressure sulfuric acid leaching and is matched with units such as resin separation and sulfide precipitation to realize cascade recovery. However, fire-wet routes generally have the problems of high energy consumption, high equipment investment and maintenance cost, remarkable process emission and the like, and pure wet routes often face pain points of high acid consumption, serious impurity co-dissolution, high equipment corrosion and safety pressure, long reaction time and the like. In order to achieve the comprehensive objectives of high recovery, low energy consumption, low acid consumption and low emission, a pretreatment technology capable of realizing effective phase change activation and structural cleavage in a very short time is needed to reduce the subsequent leaching acidity and time cost and reduce the terminal treatment pressure. Disclosure of Invention A first object of the present invention is to provide a pretreatment method of a deep sea multi-metal nodule (also referred to as a multi-metal nodule or a manganese nodule) on the sea bottom, aiming at effectively modifying the multi-metal nodule and further improving the extraction of valuable elements therein. The second aim of the invention is to provide the extraction method of valuable elements of the ocean bottom deep sea polymetallic nodule, which aims to effectively improve the extraction efficiency and effect of metals. The valuable metals (Cu, co, ni, etc.) of the deep sea polymetallic nodule are usually assigned to the skeleton phase of high valence ferromanganese oxide/hydroxide in the same manner of adsorption, complexation or class, the skeleton phase is mainly Mn (IV) and Fe (III), the structure is stable, the reactivity is low, and the method belongs to the typical difficult-to-treat phase. Under the condition that the structure of the high-valence ferromanganese oxide is not effectively destroyed, valuable metals such as Cu, co, ni and the like are tightly combined with the framework, and the conventional leaching or heat treatment is difficult to realize sufficient dissociation and high-efficiency release, so that the problems of slow leaching dynamics, poor selectivity, high medicine consumption and the like are easily represented. Aiming at the characteristics and the treatment difficulty of de