The focus decision context. Risk assessment of ments, design and development, communication and accidents concerns unplanned incidents, e. For example, LCA is traditionally used for performed. They cannot easily replace each other, so if the object of Some aspects of the decision context such as the the study is a project, EIA is the natural choice rather actor, the complexity, the uncertainty, level of improve- than LCA or another method developed for another ment, aspiration of the decision-maker and the cultural object.
The object of the study is therefore a key aspect. These choices are study can also work the other way around. The framing of tool is chosen for a particular problem, it implies that the decision may determine what is regarded as the object of study also is determined. On the other hand, if In conclusion it is suggested that the two key aspects the decision-maker is not interested in economic of the decision context determining the choice of tools impacts, and perhaps distrusts socio-economic assess- are the object of the study and the impacts of interest.
These two dimensions are used in Fig. The tools are shown in relation to their focus, i. Procedural tools are written in bold text. Tillman et al. Several of the tools focus on natural resources as treatment. The EIA provided infor- as evaluation methods for a wide range of objects. On the other hand, the LCA provided environmental impacts, it seems that for each object information on global impacts. The two tools use there is a tool that is the most suitable.
An example of an encompassing method is when suitable tool and cannot easily be replaced by other exergy analysis is used as a method for life-cycle impact tools if the focus is on the use of natural resources and assessment [46]. For example: on the same object or replace each other. Between these two ex- impacts of organisations and companies. In Fig. There are pro- types of site-dependency [55].
The combination. This means substances. If tools are to be used sequentially or chemical substances. A tentative divisions of some tools as accounting and change-orientated in relation to how they have been used and to what extent prospective or retrospective data and methodology are used. This would normally imply using that there may be some tools lacking. When the focus is some sort of marginal data. For methods used within the SEEA are mainly used for example, if an extra MJ of electricity will be used if accounting studies.
For organisations and companies a certain choice is made, this MJ is not likely to come too, there seems to be a lack of methods for prospective, from the average electricity production, but rather from change-orientated studies.
Often a distinction is made Environmental Auditing have mainly been used for between a short-term marginal assuming the current accounting purposes. However, it is clear that many capacities without any new investments and a long-term interesting applications lie in change-orientated studies. What and accounting studies may also have repercussions for types of changes in methodology and data would be other parts of LCA methodology such as choice of appropriate?
Discussions with col- lacking for other tools. However, it may be the case leagues at fms especially Jessica Johansson and the late that some of the conclusions from the discussion within Peter Steen have been useful. We are grateful for the the LCA world can be valid for other tools as well.
Proceedings of the conaccount confer- the LCM Conference [7]. Comments at these meetings ence 11e12 September. Wuppertal Special 6. Statistics Sweden have been valuable.
Washington, D. An evaluative framework for conceptual Kleijn R, Moriguchi Y, et al. The weight of nations. Material and analytical approaches used in environmental management. The Journal of Corporate Resources Institute; Environmental Strategy and Practice ;e Tools to aid environmental analysis, TMR and the mips-concept: a contribution to the decision making.
Wuppertal: Wuppertal Institute for compilation of 17 methods. Department for Material stekninsk forskning; Flows and Structural Change; Environmental impact assessment versus other environ- [21] van der Voet E. Substances from cradle to grave. Development of mental management decision tools.
In: Petts J, editor. Environmental impact economy and the environment of a region with case studies on assessment: process, methods and potential, vol.
London: cadmium and nitrogen compounds. Leiden University, Leiden; Heavy grammes. Life cycle assessment and conceptually related pro- metals: a problem solved? Dordrecht: Kluwer Academic Publish- grammes. Evaluation of risks of a systems perspective. Ecological Economics ;e Formulas have been developed which use the feed tonnage and assays of the two recovered values to obtain the ratios of concentration, the weights of the three products of separation, and the recoveries of the values in their respective concentrates.
For illustrative purposes data from a copper-zinc separation is assumed. The ratios of concentration, Kcu and Kzn are those for the copper and zinc concentrates, respectively, with Rcu and Rzn the percentage recoveries of the metals in their corresponding concentrates.
As follows:. The three product solution illustrated above can be somewhat simplified by taking an intermediate tailings sample between the two stages of concentration; i. It is decided to take a copper tail zinc feed sample in order to provide a check on the results calculated in the previous example. The sample CT assayed 0.
The check weights of the copper and zinc concentrates are computed using the above math. At operating plants, it is usually simpler to report the K based on assays. If more than one mineral or metal is recovered in a bulk concentrate, each will have its own K with the one regarded as most important being reported as the plant criteria.
If the tonnage of concentrates produced is unknown it can be obtained using the product assays and the tons of plant feed:. It may be calculated in several different ways, depending on the data available. The concentrate and tailings produced average I let you do the math! Frequently, a concentrator will mill a complex ore requiring the production of two separate concentrates, each of which is enriched in a different metal or valuable mineral, plus a final tailing acceptably low in both constituents.
Formulas have been developed which use the feed tonnage and assays of the two recovered values to obtain the ratios of concentration, the weights of the three products of separation, and the recoveries of the values in their respective concentrates.
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