Copper indicator plants

The correlation coefficient of the analyzed trace elements varies, on the average of the four indicator plants, between 0.38 for iron and 0.86 for nickel. The correlation coefficients for iron and copper are relatively low, with r = 0.38 and r = 0.48, whereas these for molybdenum (r = 0.63), manga-... 

A typical plant production of copper sulfate indicating water use and wastewater generation is shown in the flow diagram (Figure 22.8). 

One of the main problems associated with beneficiation of the Kolwezi siliceous ore is the production of malachite and pseudomalachte slimes that have a relatively low flotation rate. Most of the copper losses occurring in the plant are in the -15 pm fraction. Experimental testwork conducted with a different palm oil emulsifier indicated that copper recovery from the fine fraction can be significantly improved with the use of petroleum sulphonate (Petrosol 845) as the emulsifier [21] for palm oil. Significant improvement in copper recovery was realized in the fine fractions with the use of palm oil emulsified with Petrosol 845. 

The process flow sheet was first tested for direct leaching of steel mill flue dust and production of zinc metal by electrowinning. The tests were performed in a continuously operating pilot plant, producing 10-20 kg/day zinc metal. The same pilot plant was then used for treating copper/zinc-rich brass mill flue dust in a closed loop operation, recycling all the zinc solvent extraction raffinate to the copper circuit leach section. In the zinc circuit leach section, only the amount of zinc rich dust necessary for neutralization of the copper solvent extraction raffinate was used. The results obtained from the pilot plant tests indicated contamination problems within the solvent extraction loops. The estimation of economic data showed a weak return on the assets compared with the alkali route, and sensitivity toward the raw material price. 

In addition to the conventional pollutant constituents, USEPA made a survey of the presence of the 126 toxic pollutants listed as priority pollutants in refinery operations in 1977 [5]. The survey responses indicated that 71 toxic pollutants were purchased as raw or intermediate materials 19 of these were purchased by single refineries. At least 10% of aU refineries purchase the following toxic pollutants benzene, carbon tetrachloride, 1,1,1-trichloroethane, phenol, toluene, zinc and its compounds, chromium and its compounds, copper and its compounds, and lead and its compounds. Zinc and chromium are purchased by 28% of all refineries, and lead is purchased by nearly 48% of all plants. 

Copper alloys are used extensively in power plant condensers, and as a result, copper can usually go into a corrosion product film or directly into solution as an ion or as a precipitate in the initial stages of condensation by tube corrosion. As corrosion products form and increase in thickness, the corrosion rate decreases until a steady state is achieved. Studies indicate that copper release is a function of flow rate more so than of the salt content of the makeup water. 

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