Copper metal containing dust

The principal constituents of the paniculate matter are lead/zinc and iron oxides, but oxides of metals such as arsenic, antimony, cadmium, copper, and mercury are also present, along with metallic sulfates. Dust from raw materials handling contains metals, mainly in sulfidic form, although chlorides, fluorides, and metals in other chemical forms may be present. Off-gases contain fine dust panicles and volatile impurities such as arsenic, fluorine, and mercury. 

The zinc salt solutions, which currently mainly come from zinc and copper smelters, contain impurities which have to be completely removed prior to use, because all heavy metals form colored sulfides. For the purification step the solution is oxidized with chlorine (pH 4), which precipitates most of the iron and manganese as the oxide-hydrate and part of the cobalt, nickel and cadmium present as their hydroxides. In the second step, the elements nobler than zinc (Ni, Co, Cd, In, Tl, Pb, Cu, Ag) are precipitated as their metals by adding zinc dust and the metals returned to the copper smelters for noble metal extraction. After purification the solutions are adjusted to a particular zinc content. Mixtures of zinc sulfate and zinc chloride solutions are used for manufacturing lithopone types with more than 30% ZnS. 

In a wiredrawing process, a wire is considered to be subjected to steady deformation however, a copper wire containing hard inclusion matter is subjected to unsteady deformation. Even in the case of small inclusions such as metal powder and dust (coarse particulates), the ratio of inclusion diameter to wire diameter D /D becomes large for fine wires. Fig. 9. shows the deformation behavior of drawn wires containing inclusions with D,/D = 0.4. 0.6 and 0.8, as observed using FEA. Safe conditions which are Of = 6°, R/P = 20%, and coefficient of friction /jl = 0.05 are set. For comparison, a wire devoid of inclusions is also shown. In the figure, it can be seen that the meshes of the... 

Concentrated peroxide may decompose violently in contact with iron, copper chromium and most other metals and their salts, and dust (which frequently contains rust). Absolute cleanliness, suitable equipment (PVC, butyl or Neoprene rubber, Teflon) and personal protection are essential for safe handling [4],... 

Another reported example with two metals in solution is the recovery of copper and zinc from brass mill flue dust [11]. The material contains very little iron. The solid material is leached with sulfuric acid to produce a weak acid... 

Germanium also is recovered from coal that contains this metal at trace concentrations. Coal ash and fine dusts are mixed with sodium carbonate, copper oxide, calcium oxide, and coal dust, and smelted. The crude oxide products are converted to their volatile chlorides. Germanium chloride is isolated from the condensate products hy fractional distillation. 

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. 

Concentrated peroxide may decompose violently in contact with iron, copper chromium and most other metals and their salts, and dust (which frequently contains... 

Toxic effects Dust is an irritant to eye and respiratory tract. Notes The metal must be pure silver for explosive purposes. Do not use "sterling" silver, as it contains a high percentage of copper. 

---