The method of x-ray electronic spectroscopy investigated influence of strontium, bismuth and a lead and tin alloy on structure of superficial films of powders of oxide of aluminum. It is established that alloying additives are surface-active substances and concentrate mainly in a blanket, partially being oxidized together with aluminum. Being formed superficial films have impact on consumer properties of aluminum powders.
At the nickel plant of the Republic of Cuba, at industrial and pilot plants in a number of countries, reduction roasting of oxidized nickel ore before ammonia leaching is carried out in multi-pod furnaces with mechanical overheating. The specific productivity of these furnaces is relatively low. Experience accumulated in non-ferrous metallurgy on fluidized bed roasting, as well as the results of studies of magnetizing fluidized bed roasting in ferrous metallurgy suggest that a similar process can be recovered oxidized nickel ore before ammonia leaching. The first exploratory experiments in this direction were carried out at a large laboratory installation at the Institute of Petroleum of the AS USSR.
In the process of fuming zinc, lead, tin and rare metals contained in molten slag are extracted into vogons. The process was first carried out in 1927 and has not changed significantly since then. There are currently about 10 fusion plants in operation around the world. All of them consist of a caissonized shaft furnace in which a suspension of coal dust in the air is blown through a layer of molten slag. The coal dust is the fuel by combustion of which the required temperature of the slag is maintained. As a rule, the excess air to coal dust ratio in the blast is about 0.7. Partial combustion of coal creates a reducing atmosphere in the furnace. By varying the air-to-coal ratio, the process is controlled, the amount of heat generated and the degree of slag recovery are varied.