Boliden Aktiebolag

Martin L Hedlund

Malkolm S Lundstrom

Kurt J Buren

Johan S Leirnes

Method for working-up waste products containing valuable metals

The invention relates to a method for recovering lead and lead-alloying elements from battery-type lead waste products, and fractions thereof, such as battery mud, and similar oxidic-sulphatic materials. In accordance with the method, the waste products, together with a solid reduction agent, are introduced to a furnace in which the contents thereof can be vigorously agitated. The amount of solid reduction agent charged is selected so as to ensure the chemical reduction of substantially all the non-metallic lead contained by the waste products, and the alloying elements present therein. The material charged to the furnace is heated to a temperature of between about 1050.degree. C. and 1250.degree. C., while vigorously agitating the furnace contents, so as to melt, split-off and chemically reduce the waste products, to form a lead melt containing the aforementioned alloying elements. The furnace used is preferably a top-blown rotary converter of the Kaldo type, in which the furnace contents can be agitated by rotating the furnace.

Method for recovering lead from waste lead products

The invention relates to a method for producing lead from moist lead-sulphide concentrates and oxidic and/or sulphatic lead raw materials by the known roasting and reaction process. According to the method granules or pellets of oxidic and/or sulphatic lead raw materials are brought together with the moist lead concentrate in a drum-like vessel arranged for rotation about its longitudinal axis. Said moist concentrate is dried while rotating said drum-like vessel to form sulphide-containing granulates. The formed granulates are introduced into a furnace together with flux in given proportions. The charge is vigorously agitated and turbulence created in the resultant melt, while effecting the roasting and reaction process to form a liquid slag and a molten lead phase. Both the drying and the smelting may be provided in the same unit if a top-blown rotary converter is employed.

Method for producing lead from sulphidic and oxidic and/or sulphatic

The invention relates to a method for producing lead having a sulphur content beneath about 2%, from sulphur-containing oxidic lead raw materials contaminated with zinc and/or other readily oxidized elements, by smelting the materials in a furnace in which the furnace contents can be agitated. When practicing the method, the lead raw materials are charged to the furnace together with iron-containing fluxes and solid reduction agents. The charged materials are heated under agitation, to form a lead phase and a slag phase. The amount of reduction agent charged is selected so that at least all the lead contained in the furnace is reduced to lead metal and the amount and composition of the fluxes are selected so that a terminal slag is obtained in which the sum of the iron and zinc present is 30-40%, and so that the slag has a content of 15-25% of both SiO.sub.2 and CaO+MgO. Lead raw materials, fluxes and reduction agents are suitably introduced in a plurality of charges, with intermediate moderate heating, prior to commencing the smelting process.

Growing community of inventors

Ursviken, Sweden

Martin L Hedlund