1、 外文翻译 原文 Resource Characteristics, Extraction Costs, and Optimal Exploitation of Mineral Resources Material Source: spingerlink Author: A. MARVASTI I. Marine Mining Potentially exploitable marine minerals are vast in numbers and in variety. There are approximately 90 different mineral commodities in
2、 the marine environment including oil and gas; heavy mineral placers containing gold, chromium, platinumgroup minerals, tin, and titanium; phosphorite; manganese nodules and crusts containing cobalt, nickel, copper, and manganese; polymetallic sulfides; and sand and gravel. In this section of the pa
3、per, discussions focus on some non-hydrocarbon marine minerals. Perceptions of increasing scarcity of most land-based resources in the U.S.,both in terms of depletion and deepening of reserves, and the lack of reliability in some of the developing country suppliers of minerals have encouraged intere
4、st in the mineral resources from the oceans. In some industries such as phosphate mining, there have been other contributing factors including competition from low-cost foreign producers, increasing environmental pressures, and rising interest in alternative uses for land in the mining areas (Marvas
5、ti and Riggs 1989). Scientific ocean explorations have proven the existence of significant amount of many minerals (McKelvey et al. 1983; Clark and Clark 1986; Rowland 1985; Manheim 1986; Dubs 1986; Office of Technology Assessment 1987; Thiel and Schriever 1993). A comprehensive review of the potent
6、ial world ocean mineral resources by Broadus (1987) identifies cobalt, nickel, manganese, copper, zinc, hafnium, zirconium, and ilmenite among seabed material commodities constituting from 25 to as high as 220 percent of the total land-based resources in their group. Anderson (1991) maintains that t
7、he average grade for cobalt and manganese in manganese nodules is higher than in the land-based deposits which are currently mined.Technologically, various mining methods are available for the recovery of marine mineral resources. For example, mechanical mining systems such as drag line, clam shell,
8、 and bucket-ladder dredges have been commercially used to recover sand and gravel, and gold placers. The mining of seabed minerals is also currently feasible with the hydraulic slurry technology. Although, this technology has been commercially used for sulphur mining recently, it is yet to be tested
9、 on a large-scale commercial basis to recover manganese nodules. In the 1970s, there was an increasing interest by large companies and governmentalorganizations from various industrialized countries in the commercial exploitation of seabed minerals, particularly manganese nodules. This was indicated
10、 by millions of dollars spent on exploration activities and technological development, and the high number of patents granted during this period (Broadus 1987). Estimated seabed mining expenditures and patent activity from 1969 to 1984.(Source: Broadus, 1987) Since the level of demand for minerals i
11、s absent in the exploration model, the impact of price fluctuations on the level of exploratory effort cannot be analyzed in equation (6).Many experts believe that commercial production of most marine minerals willnot occur in the near future because of unfavorable economic conditions (Dubs 1986; Of
12、fice of Technology Assessment 1987; Broadus 1987). This could be true in spite of a higher grade of some seabed resources in comparison with the landbased minerals which are currently mined. For example, a geological review of phosphate resources within the U.S. continental shelf concludes that the
13、off-shore phosphate resources of North Carolina have a high quality which makes thempotentially competitive with the existing land-based resources (Marvasti and Riggs 1987). Significant quantity of highly concentrated phosphate is also found in the surficial glauconitic sands on the Chatham Rise, of
14、f the east coast of New Zealand (Kudrass 1984). Another example of valuable seabed resources is manganese nodules. The metal content of these nodules is reported to be high, however, their estimated extraction cost is currently higher than the cost of land-based mining. Nevertheless, since the metal
15、 content of land-based ores is generally declining, mining of manganese nodules is believed to be economically feasible in the first quarter of the new century (Dubs 1986).The extraction of marine minerals is likely to become an increasingly attractive choice. However, the cost of initiating commerc
16、ial mining is an obstacle. In the economic literature, it is commonly assumed that firms invest incrementally and continuously. But, capacity choice and investment decisions of the firms are more complex. Pindyck (1988, 1991) argues that most investments are lumpy and largely irreversible. Therefore
17、, most of the investment expenditures are sunk costs. According to Pindyck, firms may also delay irreversible investments in order to wait for new information about prices, costs, or market conditions. The existence 402 A. MARVASTI II. Introduction of seabed mining. sunk costs and uncertain future d
18、iminish the optimum investment expenditures. Pindyck maintains that, under these conditions, a much higher internal rate of return is required to stimulate the expansion in an industry. Irreversibility of investment and sunk costs in extractive industries are theoretically analyzed (Cairns and Lasse
19、rre 1986) and empirically documented (Lasserre 1985). Investment decisions of the firm to extract ocean minerals are subject to similar consideration. In addition, there are unique problems associated with ocean mining. The following is a list of some of the factors which influence the investment de
20、cisions of firms to exploit ocean mineral resources: (1) Exploitation of ocean minerals requires high R Clark and Clark 1986; Rowland 1985; Manheim， 1986; Dubs 1986; Office of Technology Assessment 1987; Thiel and Schriever， 1993). 通过 Broadus (1987)一个潜在的世界海洋矿产资源的全面审查，鉴定出钴，镍，锰，铜，锌，铪，锆并在海床构成物质商品从钛铁矿 ,
21、高达 25至 220的总土地基础为资源在他们他们组里。 Anderson (1991)维护到在锰结核里平均钴和锰含量 比在以陆地为基础的存储着要高，这就是当前的开采情况。技术上，各种采矿方法对海洋矿产资源的恢复是可用的。在 1970 s，越来越多的大公司和政府组织对海底矿物的开发感情趣。他们是来自各种各样的工业 化国家。特别是锰结核。指出到百万的美元的花费来开采和技术的开发，在这个时期很多的专利被授（ Broadus1987） .描述了海底采矿的 R D支出和专利活动 在 1969至 1984年期间。在 1969年至 1978年期间，海洋采矿的 R D支出呈上升趋势 ，反应出矿物的需要的增加和
22、 陆基储备的大小和数量在下降。因为在开发模式中矿产需求水平的缺少， 因价格波动对探索性努力水平的影响不能在公式分析。许多专家相信在不久的未来，大部分海洋矿物的商业性生产将不会出现。因为这个不利的经济条件（ Dubs1986; Office of Technology Assessment 1987; Broadus 1987） . 这个可能会是真实的，尽管高级别的海底资源与陆基矿物资源在比较着，并且在开采着。举个例子，一个在美国大陆架的磷矿资源地质论评的结论是，离岸北卡罗莱纳州磷矿资源具有较高的质量，使他们可能与现有的土地为基础的资源展开竞争。 (Marvasti and Riggs 1987
23、). 在新西兰东海岸的高浓度磷肥的重大数量也发现在地表上的查塔姆崛起的 glauconitic砂 (Kudrass 1984)，另外一个例子，宝贵的海底资源是海底锰结核。报告指出这些锰结核的金属含量很高，然而，他们的存在的花费比陆基资源的花费要高。不过，因为这个陆基资源金属含量的下降被认为是新世纪头 25年经济师可行的。海洋矿产资源的开采可能变的越来越成为吸引人的选择。然而，商业性开采的成本是一个障碍。在经济学文献中，一般认为，企业投资时不断增长的，但是，公司在容量上的选择和投资的决策变的越来越复杂 Pindyck (1988, 1991)指出大部分的投资是块状的和很大程度上是不可逆转的。因此
24、，大部分的投资的支出是沉没成本。根据 Pindyck，公司也会延迟投资，为了等待新的信息包括价格，成本，市场条件等 . 2.介绍海底采矿： 沉没成本和未来不确定的投资支出开始减少， Pindyck指出：在这种情况下，一个内部更高的回报率是要求一个行业发展来刺激的。投资在采掘业和沉没成本的不可逆性进行了理论分析和经验记录。公司投资决定的提出是受海外矿产考虑的。另外，那里有一个唯一的问题关系到海外矿产资源。以下是一系列的原因，影响企业的投资决策，去开发海洋矿产资源：（ 1）发海外矿产资源要求高 R & D成本去完成新技术的而开发。各种各样的技术被开发了，但是他们 没有商业化的测试。（ 2）开发成本
25、和资源鉴定费用比较高。（ 3）规模经济由于高资本成本和大型植物将证明新的投资仅仅在大量矿物需求增加时。比如说，一个锰结核开采矿区可以生产多达 6%的世界总产量和 75%的钴对美国的需求。 (4)沉没成本的存在，假如当前土地为基础的矿物是被抛弃的。 (5).至少 5年到 10年的时间滞后，在矿物投资的开发和技术的开发和商业化生产的开始。因此公司将不得不忍受很多年的现金负流。 (6)世界上存在过剩的生产能力。因为这些经济因素，海外矿产资源将有利可图除非是大规模的发生。同时，海洋采矿将是合理的矿产 资源。 3.价格路线： 假如矿产的价格高于当前的价格，因为海洋采矿的发生，相通矿物的价格，比如钴严重的
26、减少，因此，海洋采矿发生在商业基础上进行之前 ，现有的陆基矿物质量，一定会进一步大幅下跌。展示出大部分价格的减少的可能性，对于某些矿物产品，比如钴，在市场影响的矿物质，它是严重影响了开采海洋采矿 。矿业公司认为矿物的入境价格这个决定的做出是在大规模的开采海洋矿物，结果，一间入境前和预期入境后的矿物价格的大幅差距可以成为一个有效的进入障碍海洋的一段时间，另外这些因素，那里有一些问题，特别是在矿产的开采在来自国 际的水域，这可能会淘汰那些没有强大经济实力的团体。 4.矿产： 矿产资源的谈论作为一个作为储备总量扩张的例子，在下个世纪，它越来越起着很重要的作用在供应矿物给全世界。然而，一些矿物的潜力去满足世界的需要是黑暗的，包括海外服务的减少，材料的价格，作为很大规模的矿物的介绍 .
