PROCEDIMENTO PER IL TRATTAMENTO DI MINERALI E/O DI CONCENTRATI DI PIOMBO O DI PIOMBO ZINCO SOLFOROSI

In a method for processing lead-containing or lead- and zinc-containing sulphide ores and/or concentrates, which contain metal compounds including iron and copper compounds, silica, alumina, calcium oxide and magnesium oxide, the smelting of the charge material, composed of sulphide starting material and a flux, is carried out together with circulating oxide dust in a vertical flame envelope in a medium of an oxygen-containing gas to form an oxide melt, which preferably contains metal oxides, and a mixture of circulating oxide dust with the gases from the melting process, the said circulating oxide dust is precipitated out of the gases from the melting step and this dust is recycled to the melts, the metal oxides, preferably zinc oxide, are reduced to metals by means of filtration of the oxide melt through a layer of solid carbon-containing material, crude lead and a zinc-containing slag of low lead content being obtained, then holding of the slag is carried out with formation of lead-containing zinc vapours, which are oxidised with oxygen-containing gas, coarse- and fine-disperse oxide sublimates arising. The flux used is a mixture of limestone or lime with an iron-containing material [CaO : Fe mass ratio = 0.43 to 0.76/in a quantity of 5 to 22 %, relative to the mass of... Original abstract incomplete.