Aluminum thermal method
Aluminum thermal method must use high-quality manganeseore as raw material, and the aluminum consumption is large, high cost; thesilicon thermal power has a long process, the operation is relatively complex; theelectrolysis method widely used because of it can use poor manganese ore as rawmaterials to obtain high purity manganese metal products.
Aluminum thermal method, in magnesialining-up vertical furnace, use aluminum as reducing agent, the process ofreducing manganese oxides (Mn2O3 or Mn3O4) output of manganese metal. In orderto get qualified products, aluminum thermal method generally used low impuritymanganese oxide minerals as raw materials. The pulverized manganese oxide isabout 90% of the theoretical requirement of the aluminum particles and theequivalent amount of aluminum 10% to 20% of the lime mixed evenly, manganesemetal ignition reduction to obtain manganese metal contains more than 90%manganese.
The silicon thermal methods, while treatingnon-quality manganese ore, generally use a three-step reduction. The firststep, add a small amount of manganese ore with coke in an electric furnace torestore, get low iron and low phosphorus manganese-rich slag. The second step, usecharcoal reduce manganese-rich slag, refining low phosphorus carbonferromanganese; low phosphorus carbon ferromanganese plus silica, charcoalrefining high silicon-manganese alloy. The third step, use high siliconmanganese alloy and manganese-rich slag with lime, to desilication refined inan electric arc furnace, get a purity of 93% to 97% manganese metal.
The electrolytic method, the electrolytic manganesemetal is the production of manganese powder, the rawmaterial can be manganese oxide or manganese carbonate. If use the manganeseoxide minerals as raw materials, adding reduce agent directly leaching, alsocan be through reducing roast and then leaching. The process of using manganesecarbonate as raw material is composed of leaching, oxidation, purification andelectrowinning and other operations.
Leaching, used the anolyte returned tosulfuric acid and electrolytic deposition process as the solvent, in acidleaching tank added slurried the manganese carbonate powder. Under theconditions of acid mine 0.5 to 0.55, 363K leaching temperature, leaching 4 ~8h, control leaching endpoint, pH1.0 to 1.5, then the manganese of MnCO3 will generatewater-soluble MnSO4 into the solution.
The oxidation, the purpose is to remove theiron, aluminum and other impurities in leaching solution. Often use manganesedioxide powder as the oxidant, oxidized the divalent iron in the leach solutioninto trivalent iron, use liquid ammonia or lime as the neutralizing agent,adjusted the solution to pH 7.0 ~~ 7.2, so that impurities such as iron,aluminum hydrolysis removed by precipitation.
Purification, the qualified lixivium aftercoarse filtration, the filtrate was sent for purification. Cleaning operationcarried out in the purge vessel, added the purification agent in tank to remove.The purified solution by the fine filter, is the new agentDiethyldithiocarbamate (of diethyl sulfonitriding ammonium sodium formate) orsulfide liquid heavy metal precipitation required by electrolytic deposition.
Electrolytic deposition, there are certainrequirements on the quality of the new liquid heteroaryl. Manganeseelectrowinning use diaphragm electrolysis. Electrolytic cell with a diaphragm divideinto an anode chamber and a cathode chamber, the anode is generally use silver,tin, antimony, lead alloy sheet, the net area of the anode conductive is 60% to 65% of cathode conductive area, the current density is 40% to35% higher than the cathode. The cathode generally used titanium, cathodecurrent density is 450 to 500A/m.The cell voltage is about 5V. The electrolytic deposition new liquid by thehigh slot sent to the cathode chamber, the anolyte containing MnO2 dischargedfrom the bottom of the groove. When the manganese metal deposited a thicknessof 1.5 ~ 2mm on the cathode(Usually electrolytic 24h), remove the cathode plate, and placed in a newcathode plate to continue electrolysis. The removed cathode was through cleaning,drying, peeling from the metal manganese. The peeled manganese metal by equippedis electrolytic manganese product.
Article Tags: Aluminum Thermal Method, Manganese Metal, Aluminum Thermal, Thermal Method, Manganese Oxide, Manganese-rich Slag, Pan Head Screws Manufacturers Manganese Carbonate, Electrolytic Deposition