Production Method Of Iron Oxide
Production method of Iron Oxide
Hydrogen reduction of α-Fe2O3
The high purity fine powder α-Fe2O3 into the disk, the powder layer should not be too thick. After the plate is placed in the reaction tube, the high purity nitrogen is passed to completely replace the air. And then through the gas cylinder slowly into the water saturated with hydrogen. The heating temperature is preferably 300 to 400 ° C (for example, 330 ° C). (Usually 1 ~ 3h) after cooling, stop sending hydrogen, and then replaced with nitrogen, remove the sample. Water vapor is insufficient, heating temperature is too high or excessive reduction will produce FeO, it must be noted. Improve the temperature of the gas cylinder can increase the amount of water vapor (40 ~ 60 ℃ more appropriate). Α-Fe2O3 was obtained by heating dehydration with acicular α-FeO (OH) as the starting material. With this α-Fe2O3 can be obtained needle-like iron oxide particles. Black recording tape is to use this iron oxide as a tape recording media;
Ferrous sulfate and sulfuric acid in the reaction of sulfuric acid in the order of ferrous sulfate, and then add caustic soda and Iron Oxide at 95 ~ 105 ℃ for the formation of iron oxide reaction, by filtration, drying, crushing the iron oxide black;
When the aqueous solution containing ferrous hydroxide precipitates is heated to 70 ° C or higher and slow oxidation is carried out, it is possible to obtain a tetra-iron oxide powder composed of fairly uniform octahedral or cubic single crystal particles having a length of about 0.2 μm. It is also possible to use air bubbles as a means of oxidation. It is also possible to use an oxidizing agent like KNO3;
In the case of skilled operation, iron oxide can be obtained by chemical composition of Fe3.00O4.00. Harber method is used to add 220 g of 20% aqueous ammonia to 2.2 L of FeSO4.7H2O aqueous solution and boil under the condition of breaking air (which can be filled with capillary Round bottom flask), boiled with a concentrated solution containing 25.5 g of KNO3;
Ferrous sulfate solution alkali oxidation or iron salt and ferrous salt solution by a certain percentage of mixed with alkali precipitation obtained.