Smelt defined

Following my appointment to the Department of Geology in September 1968 rock geochemical studies were undertaken on five Palaeozoic Zn-Pb (Cu) massive sulfide deposits in northern New Brunswick. A total of 115,000 analyses were performed on 13,000 rock samples from the environs of the Heath Steele B and ACD zones, BMS (Brunswick Mining and Smelting) No. 12, Caribou and Key Anacon sulfide deposits. In all cases significant anomalies were defined. 

Analysis, yielded a well-defined finger-print for these Zn smelting industries they could be characterized by a Zn/Cd factor, in which Cd and Zn were obtained in a 1 212 relative abundancy (De Bruin et al., 1987). 

Fe-S-O Matte Composition Under Defined Zinc Smelting Conditions... 

The main components of the present smelting system are Zn-Fe-S-0. If the Zn-Fe-S-0 matte is in equilibrium with a gas phase containing zinc, there are four degrees of freedom of the system. The four independent variables can be defined as ... 

An azns=0.05 to 0.1 corresponds to a 1-2 wt% zinc solubility in the matte because the activity coefficient, yzns >n the matte is about 10 as moitioned earlier. Because the Zn solubility in a Fe-S-0 matte is very low under these conditions, the matte can be considered a Fe-S-0 temaiy system whose composition is defined at a fixed temperature, oxygen potential and sulfur potential. Based on the reported relationship between the Fe-S-0 matte composition, temperature, oxygen and sulhir potentials (2), Fe-S-0 matte compositions under the described smelting conditions have been estimated see Table I. At 1350°C and a CO/CO2 ratio between 3 and 4, azns=0.05 (or less than 1% Zn solubility in matte) requires the composition of matte of 6-7% O and Fe/S 2.7-2.9 (weight basis). The proposed matte smelting composition is shown in Figure 2 (6). 

In a smelting process some of the contaminants that are a serious concern in electrolytic zinc plants e.g., Mn, Fe, Co, Ni, Ge, Hg are of minor consequence. The distribution of arsenic, antimony and bismuth cannot be fully defined imtil a prototype plant is operated, but a matte and an iron-rich slag should provide a good outlet for them. 

Surface Area, Porosity, and Permeability. Some very interesting and important phenomena involve small particles and their surfaces. For example, SO2 produced from mining and smelting operations that extract metals such as Cu and Ph from heavy metal sulfide ores can be oxidized to SO3 in the atmosphere, thus contrihutingto acid rain problems. The reaction rate depends not only on the concentration of the SO2 bnt also on the siuTace area of any catalyst available, such as airborne dnst particles. The efficiency of a catalyst depends on its specific surface area, defined as the ratio of siuTace area to mass (17). The specific snrface area depends on both the size and shape, and is distinctively high for colloidalsized species. This is important in the catalytic processes nsed in many indnstries for which the rates of reactions occurring at the catalyst siuTace depend not only on the concentrations of the feed stream reactants bnt also on the sinface area of catalyst available. Since practical catalysts freqnently are snpported catalysts, some of the sinface area is more important than the rest. Since the supporting phase is usnally porous the size and shapes of the pores may influence the reaction rates as well. The final rate expressions for a catalytic process may contain all of these factors sinface area, porosity, and permeability. 

Industrial hygiene began life in the metals trade. Mining and smelting of metals were the backbone of technological and industrial growth. Indeed, whole eras of human development are associated with the increasing sophistication with which humankind has worked with metals the copper age was succeeded by the bronze age that was in turn succeeded by the iron age. We are embarked on a new age characterized by new materials that define our civilization it may eventually be known as the silicon age. 

Figure 9. Comparison of the net energy consumption, defined as [Energy Spent] - [Useful Work Produced], for Looping Suifide Oxidation " and the conventional flash smelting process. ISO reduced the net energy...

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