Smelting dust lead concentrations

Dried lead concentrate, flux, and return dust are added to the converter through a lance during the smelting cycle. Oxygen enriched air is injected at the same time to carry out the smelting reactions and maintain the temperature. Once smelting is completed, the air is shut off and the reduction carried... 

The metallic arsenic is obtained primarily from its mineral, arsenopyrite. The mineral is smelted at 650 to 700°C in the absence of air. However, the most common method of production of the metal involves reduction of arsenic trioxide, AsOs with charcoal. Arsenic trioxide is produced by oxidation of arsenic present in the lead and copper concentrates during smelting of such concentrates. The trioxide so formed, readily volatilizes and is collected in a dust flue system where further treatment and roasting can upgrade the trioxide content. The trioxide vapors are then condensed and further purified by pressure leaching and recrystallization techniques. It is then reduced with charcoal to give metallic arsenic. 

It has special features which set it apart from other direct smelting processes. It is unsuitable for large-scale production, but is flexible in operation and can treat a range of secondary materials (including scrap batteries) and recycled dusts and residues (containing lead, zinc and copper), as well as lead concentrates. It utilises one rotating furnace, which is completely enclosed in a vented enclosure, into which batches of dry, fine feed and oxygen are introduced. 

The abundance of indium in the earth s cmst is probably about 0.1 ppm, similat to that of silver. It is found in trace amounts in many minerals, particulady in the sulfide ores of zinc and to a lesser extent in association with sulfides of copper, tin, and lead. Indium follows zinc through flotation concentration, and commercial recovery of the metal is achieved by treating residues, flue dusts, slags, and metallic intermediates in zinc smelting and associated lead (qv) and copper (qv) smelting (see Metallurgy, EXTRACTIVE Zinc and zinc alloys). 

Production. Indium is recovered from fumes, dusts, slags, residues, and alloys from zinc or lead—zinc smelting. The source material itself, a reduction bullion, flue dust, or electrolytic slime intermediate, is leached with sulfuric or hydrochloric acid, the solutions are concentrated, if necessary, and cmde indium is recovered as 99+% metal. This impure indium is then refined to 99.99%, 99.999%, 99.9999%, or higher grades by a variety of classical chemical and electrochemical processes. 

Thallium is the 59th most abundant element found in the Earths crust. It is widely distributed over the Earth, but in very low concentrations. It is found in the mineral/ores of crooksite (a copper ore CuThSe), lorandite (TLAsS ), and hutchinsonite (lead ore, PbTl). It is found mainly in the ores of copper, iron, sulfides, and selenium, but not in its elemental metallic state. Significant amounts of thallium are recovered from the flue dust of industrial smokestacks where zinc and lead ores are smelted. 

In another industrial process, flue dusts from smelting lead and zinc concentrates are boiled in acidified water. Thallium dissolves and is separated from insoluble residues by filtration. Dissolved thallium in solution then is precipitated with zinc. Thallium is extracted from the precipitate by treatment with dilute sulfuric acid which dissolves the metal. The solution may also contain zinc, cadmium, lead, copper, indium, and other impurities in trace amounts. These metals are precipitated with hydrogen sulfide. The pure thallium sulfate solution then is electrolyzed to yield thallium. 

The bismuth oxide concentrate are rarely little on the ore production, so the materials of the reducing smelt are the bismuth oxide dross attained from the oxidizing smelt of the lead or copper anode slime[19,20,21],the bismuth oxychloride enriched from the blast fumace[22], the copper converter flue dust[23], and so on. 

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