A method of forming birnessite δ-MnO.sub.2 nanosheets is provided. The method includes oxidizing manganese (Mn.sup.2+) in the presence of a source of nitrate and a light source.

A method of forming birnessite δ-MnO.sub.2 nanosheets is provided. The method includes oxidizing manganese (Mn.sup.2+) in the presence of a source of nitrate and a light source.

A magnetic magnesium-manganese layered double metal oxide composite and preparation and application. A soluble magnesium salt and a soluble manganese salt are dissolved in water to obtain a magnesium-manganese salt complex liquid; and a soluble carbonate and a soluble hydroxide are dissolved in water to obtain a carbonate-hydroxide complex liquid; a ferroferric oxide powder is added to the carbonate-hydroxide complex liquid, and then ethanol is added for ultrasonic dispersion to obtain a dispersion liquid; then the magnesium-manganese salt complex liquid is added for aging, centrifuging, washing, drying, grinding for sieving, and calcinating at 250-550° C. to obtain a magnetic magnesium-manganese layered double metal oxide composite. The composite of the present invention has relatively strong magnetism to Cd removal, and is featured by high adsorption efficiency, rapid adsorption rate and stability. Moreover, the composite can not only immobilize Cd efficiently, but also can be separated and recycled by magnet.

A magnetic magnesium-manganese layered double metal oxide composite and preparation and application. A soluble magnesium salt and a soluble manganese salt are dissolved in water to obtain a magnesium-manganese salt complex liquid; and a soluble carbonate and a soluble hydroxide are dissolved in water to obtain a carbonate-hydroxide complex liquid; a ferroferric oxide powder is added to the carbonate-hydroxide complex liquid, and then ethanol is added for ultrasonic dispersion to obtain a dispersion liquid; then the magnesium-manganese salt complex liquid is added for aging, centrifuging, washing, drying, grinding for sieving, and calcinating at 250-550° C. to obtain a magnetic magnesium-manganese layered double metal oxide composite. The composite of the present invention has relatively strong magnetism to Cd removal, and is featured by high adsorption efficiency, rapid adsorption rate and stability. Moreover, the composite can not only immobilize Cd efficiently, but also can be separated and recycled by magnet.

To provide electrolytic manganese dioxide excellent in packing property and high-rate discharge characteristics when used as a cathode material for alkaline dry cells. Electrolytic manganese dioxide in which the half-value width of the (110) plane in XRD measurement using CuKα line as the radiation source is at least 1.8° and less than 2.2°, the peak intensity ratio of X-ray diffraction peaks (110)/(021) is at least 0.70 and at most 1.00, and the JIS-pH (JIS K1467) is at least 1.5 and less than 5.0; a method for producing the electrolytic manganese dioxide; and its application.

To provide electrolytic manganese dioxide excellent in packing property and high-rate discharge characteristics when used as a cathode material for alkaline dry cells. Electrolytic manganese dioxide in which the half-value width of the (110) plane in XRD measurement using CuKα line as the radiation source is at least 1.8° and less than 2.2°, the peak intensity ratio of X-ray diffraction peaks (110)/(021) is at least 0.70 and at most 1.00, and the JIS-pH (JIS K1467) is at least 1.5 and less than 5.0; a method for producing the electrolytic manganese dioxide; and its application.

A method for synchronous production of manganese tetraoxide and ferric oxide for a soft magnetic material by using marine polymetallic nodules includes: 1) crushing and grinding marine manganese nodules and baking to a constant weight; thoroughly mixing with a mixed flux and roasting in a muffle furnace; 2) carrying out solid-liquid separation, washing solid-phase precipitates with water, grinding the solid, adding sulfuric acid, controlling the temperature to be below 50° C., and vacuuming a reactor up; 3) adding a reducing agent to react at room temperature for 5-10 min, adding ammonia water to adjust the pH value to 5.5, and carrying out separation and filtering; 4) controlling the temperatures of manganese sulfate and ferric sulfate solutions to be below 50° C., and adding ammonium sulfide; and 5) washing with deionized water, and calcining at 800-900° C. for 1-3 s by a suspension low-temperature instantaneous firing system.

A method for synchronous production of manganese tetraoxide and ferric oxide for a soft magnetic material by using marine polymetallic nodules includes: 1) crushing and grinding marine manganese nodules and baking to a constant weight; thoroughly mixing with a mixed flux and roasting in a muffle furnace; 2) carrying out solid-liquid separation, washing solid-phase precipitates with water, grinding the solid, adding sulfuric acid, controlling the temperature to be below 50° C., and vacuuming a reactor up; 3) adding a reducing agent to react at room temperature for 5-10 min, adding ammonia water to adjust the pH value to 5.5, and carrying out separation and filtering; 4) controlling the temperatures of manganese sulfate and ferric sulfate solutions to be below 50° C., and adding ammonium sulfide; and 5) washing with deionized water, and calcining at 800-900° C. for 1-3 s by a suspension low-temperature instantaneous firing system.

The present disclosure belongs to the technical field of lithium battery recycling, and discloses a method for separating and recovering valuable metals from waste ternary lithium batteries. The method includes the following steps: adding a persulfate to a waste ternary lithium battery powder, and conducting oxidative acid leaching to obtain a leaching liquor and a leaching residue; adding an alkali to the leaching liquor to allow a precipitation reaction; adding a sulfide salt to allow a reaction; adjusting a pH to allow a precipitation reaction to obtain a nickel hydroxide precipitate and a liquid phase A; adding a carbonate to the liquid phase A to allow a reaction, and conducting solid-liquid separation (SLS) to obtain lithium carbonate; and subjecting the leaching residue to calcination, adding a chlorate, heating a resulting mixture, and conducting SLS to obtain manganese dioxide.

The present disclosure belongs to the technical field of lithium battery recycling, and discloses a method for separating and recovering valuable metals from waste ternary lithium batteries. The method includes the following steps: adding a persulfate to a waste ternary lithium battery powder, and conducting oxidative acid leaching to obtain a leaching liquor and a leaching residue; adding an alkali to the leaching liquor to allow a precipitation reaction; adding a sulfide salt to allow a reaction; adjusting a pH to allow a precipitation reaction to obtain a nickel hydroxide precipitate and a liquid phase A; adding a carbonate to the liquid phase A to allow a reaction, and conducting solid-liquid separation (SLS) to obtain lithium carbonate; and subjecting the leaching residue to calcination, adding a chlorate, heating a resulting mixture, and conducting SLS to obtain manganese dioxide.