Chemical properties
If it is used and stored in accordance with the specifications, it will not decompose. There is no known dangerous reaction and avoid contact with halogen, hydrogen peroxide, hydrogen sulfide and the like.
Nickel oxide obtained by low temperature has chemical activity, and nickel monoxide obtained by calcination at a high temperature of 1000 ° C is greenish yellow and has low activity.
The color turns yellow when heated. When heated to 400 ° C, the oxygen in the air is absorbed to form Ni 2 O 3 , and at 600 ° C, it is reduced to NiO. Soluble in acid and ammonia. Insoluble in water. [4]
The reaction formula is: 4NiO+O2==400°C==2Ni2O3, 2Ni2O3==600°C==4NiO+O2.
2 production methods
1. NiCO3 or Ni(NO3)2·6H2O is placed in a platinum crucible, heated at 1000 to 1100 ° C for 6 h, and then cooled in N 2 without O 2 . If cooled in air, the surface will crust (Ni2O3), which can be removed by reduction at 100 °C with H2. [4]
NiCO3NiO+CO2↑
Ni(NO3)2·6H2ONiO+2HNO3+4H2O
2. NiCO3 is placed in a pear-shaped decomposer and repeatedly filled and with N2 without O2 to remove the air therein. The apparatus was then evacuated to a high vacuum at 100 ° C and heated to 350 ° C for 90 min. The product was transferred to a previously prepared glass bubble and sealed. [4]
NiCO3 NiO+CO2↑
3. The nickel carbonate method and the ammonia method are used. The nickel carbonate method is to dissolve gold scrap nickel in sulfuric acid or nitric acid, add soda ash to form nickel carbonate, and then wash, dry and burn. The ammonia method is to dissolve the nickel waste, add ammonium sulfate to form ammonium nickel sulfate, and then obtain by dehydration, calcination and pulverization. [4]
Ni+H2SO4====NiSO4+H2↑
NiSO4+Na2CO3====Na2SO4+NiCO3
NiCO3NiO+CO2↑
4, nickel salt calcination decomposition method nickel alloy scrap (including iron, copper, chromium, etc.) by using hydrogen sulfide, hydrogen peroxide, sodium carbonate, ammonia to remove impurities such as copper, iron, manganese, chromium, and sulfuric acid to produce sulfuric acid Nickel ammonium, which is then calcined and pulverized to obtain a finished nickel oxide. [4]
(NH4)2Ni(SO4)2=====NiO+SO3+(NH4)HSO4+NH3[5]
