Evaluating a small deposit next to an economically viable gold mine in West Africa from the points of view of the mining company,the government and the local community

This paper addresses the question of evaluating how much the different stakeholders stand to gain from a mining project. By carefully analysing the breakdown of the cash-flows generated, we were able to estimate the amounts received by the local community and by the national community (outside the mining area), the taxes and royalties received by the government and the profits made by the mining company. A real options framework was used to take account of the inherent uncertainty on the commodity price and the reserves, and the operating flexibility (that is, the possibility for the company to stop mining if the commodity price drops and/or the reserves prove to be lower than that had been envisaged). A synthetic case-study of a gold mine in West Africa was used to illustrate how this procedure could be applied in practice. By using the real option framework we were able to envisage scenarios for developing an extension to a deposit as a function of future values of the commodity price. The procedure proposed should provide governments and NGOs with more objective data for making policy decisions.     

Derivative mine valuation: strategic investment decisions in competitive markets

Successful management in competitive markets requires evaluation methods that respond to global market dynamics and provide investors with relevant information to make strategic investment decisions. These strategic decisions include decisions on investment timing, feasibility study and risk management and mine operating options. Conventional methods do not have the built-in capabilities to help investors handle these strategic issues. Advances in modern finance have had profound impacts on financial markets for options, futures and collaterized securities and offer appropriate tools in solving these problems. In this paper, the authors have extended the Brennan and Schwartz mineral resource model to develop the derivative mine valuation method based on the dynamic arbitrage theory. A copper mining venture has been evaluated using the derivative mine valuation and conventional methods. The results show that the derivative mine valuation method allows investors to maximize the venture's market value by exercising these strategic options.     

Valuing uncertain asset cash flows when there are no options: A real options approach

The real option valuation method is often presented as an alternative to the traditional discounted cash flow (DCF) approach because it is able to quantify the additional asset value arising from flexible asset management. However, these two valuation methods differ on a more fundamental level: their approach to determining the effects of cash flow uncertainty on asset value. Real option valuation adjusts for risk within the cash flow components while the DCF method discounts for risk at the aggregate net cash flow. This seemingly small difference allows the real option method to differentiate assets according to their unique risk characteristics, while the conventional DCF approach cannot.This paper presents an overview of the real options and conventional DCF frameworks for valuing uncertain cash flows. To emphasize the approaches' different treatment of risk we assume an absence of managerial flexibility. Using simple algebra, this paper demonstrates that the traditional DCF method fails to adequately discount net cash flow risk, no matter what discount rate is used. Finally, in a stylized mining example we show that DCF rules would lead a developer to forego $24.5 million in value creation, at a profitability index of 1.49, by making a poor investment decision.     

稻田甲烷排放量估算和减缓技术选择

根据中国不同生态类型地区的稻田甲烷排放通量，估算了中国稻田甲烷排放总量。结果表明，１９９０年中国稻田甲烷排放总量为１１．３３５Ｔｇ。提出了一些减缓稻田甲烷排放措施，包括：（１）使用稻田甲烷抑制剂；（２）肥料管理；（３）水分管理；（４）筛选低排放率、高产的水稻品种。     

Decommissioning a phosphoric acid production plant: a radiological protection case study

During a preliminary survey at the area of an abandoned fertilizer plant, increased levels of radioactivity were measured at places, buildings, constructions and materials. The extent of the contamination was determined and the affected areas were characterized as controlled areas. After the quantitative and qualitative determination of the contaminated materials, the decontamination was planned and performed step by step: the contaminated materials were categorized according to their physical characteristics (scrap metals, plastic pipes, scales and residues, building materials, etc) and according to their level of radioactivity. Depending on the material type, different decontamination and disposal options were proposed; the most appropriate technique was chosen taking into account apart from technical issues, the legal framework, radiation protection issues, the opinion of the local authorities involved as well as the owner’s wish. After taking away the biggest amount of the contaminated materials, an iterative process consisting of surveys and decontamination actions was performed in order to remove the residual traces of contamination from the area. During the final survey, no residual surface contamination was detected; some sparsely distributed low level contaminated materials deeply immersed into the soil were found and removed.