Discussion on Nontraditional Mineral Resources

INTRODUCTION

Mineral resources is nonrenewable. Limited traditional mineral resources have been gradually used up, resulting in the shortage of mineral resources for future economic development. On the other hand, the emerging industries demand for more mineral resources. All of these questions are focused on how to find and develop adequate resources so as to satisfy the needs of social and economic development in the world. The way to solution to these questions is that nontraditional resources could substitute for traditional resources as much as possible. Nontraditional resources refer to that kind of potential mineral resources that are neither considered nor used on the present technological and economic conditions, or to those mineral resources that are too difficult to locate because of geological complexity. Therefore, it is necessary for geological community to establish the theory system of nontraditional mineral resources.

As we know, the demand for mineral resources is increasing in the 21st century in either developing or developed countries, where the mineral mining is one of the most important part of national economy. A serious situation we have to face at present is the absence of explored mineral resources. For example, a prediction reported in 1981 that the present proved resources would have been exhausted in the next several years. For examples, Cu would have been exhausted in 9 years, petroleum 7 years, natural gas 5 years, Pb 6 years and Zn 6 months, if developing countries had consumed the mineral resources at the same level as that of America.

Therefore, the research on the nontraditional mineral resources is not only significant to meeting human needs in the 21st century, but also important to geological community. Our research results show the following three points: (1) In the new century, the discovery and exploration of nontraditional deposits will be needed. (2) Nontraditional resources will gradually play a more and more important role in the 21st century. (3) Industrialized production will demand for the nontraditional mining system in line with the new standard of environmental protection.

MAJOR SYSTEM OF NONTRADITIONAL MINERAL RESOURCES

The system of nontraditional mineral resources include nontraditional resources, research methods, mining and mineral economics. The relationship among them is shown in Fig. 1.

Figure  1.  System of nontraditional mineral resources.

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Nontraditional Resources

Nontraditional resources include new types of ore deposits, new scopes of ore deposits, new depth of ore deposits, new technical exploration and new utilization of minerals. Discovery and exploration of the new type of ore deposits will guarantee the increasing supply of the sustainable mineral reserves, and substitute for or offset part of the traditional resources. The new technical exploration and new utilization of mineral resources are chosen as a strategy for the sustainable development of the mineral resources in the 21st century.

2.1.1   Nontraditional Research Methods

The nontraditional research is an important approach to the mineral exploration. In the 21st century the more demand for mineral resources we have, the more scientific methods for reducing exploration risk we need. In this aspect, we have to apply a more scientific method to prospecting than what we have traditionally used. From our point of view, the geo-anomaly ore-forming theory is one of the major nontraditional research methods that encompass the main concepts in scientific exploration of mineral deposits.

The concept of geological anomalies means that the geological structure of the study area differs considerably from those of its surrounding areas. Geological anomaly is necessary for the formation of special or totally new types of mineral deposits. A scholar proposed that the most important mineral deposits occur in the crust area where there is the combination of the greatest anomalous geological structures, and, therefore, the anomalous combination of the object is the most perspective. It has been indicated that most of the important commercial mineral deposits are, in comparison with their adjacent areas, associated with the special and anomalous geological features. Attention must be paid, therefore, to different and anomalous metallogenic environments.

The fact that some areas contain ore deposits and others do not although these areas may have similar geological conditions, shows that similar geological conditions are not the controlling factor for the formation of economic mineral deposits.

In this sense, more factors should be understood about the mining of mineral deposits in line with this information on exploration. In another word, we should study the associations among many factors rather than one individual factor that may control the formation of mineral deposits. On the other hand, each factor should be studied for its contribution to the formation of mineral deposits. Generally, the probability that an ore body will form is related to the associations among these factors and to the appropriate conditions.

In addition, the nontraditional research also includes other theories such as nonlinear theory, comparability theory, and geological statistics.

Nontraditional Mining

The change in mining will affect the world in the 21st century. Challenged by this change, every country has to find new approaches to the establishment of nontraditional mining system. Using the new-high techniques and the environmental protection approaches, the new mining system might be characterized by the high added value, more comprehensive func-tions and high profits (Michael and Felix, 1998). The so-called high added value refers to the high reward from the mineral resources taken as commodities. In the 21st century, we have to think about the social benefits, market demands and post-mineral economics. On the other hand, the comprehensive utilization of useful ore elements and ore deposits will also be under investigation for the comprehensive prediction of regional resources such as territorial resources, plantation and mineral.

Nontraditional Mineral Economics

Mining is indispensable to the economics in every aspect, so that the mining economics is the base of evaluating the progress of the mining industry (Peter, 1994). The mining economics is usually concerned with the determination of the ore value, and specifically with the determination of the mining scale, and with the building of the smelt plant. In fact, mineral economics covers every aspect of mining and spans many geographical boundaries. Therefore, the system of strategic resources integrates economics with ore deposits, regional geology and mining in the 21st century. Therefore, the development of the mineral economics is associated with the international and domestic markets, and also with the international and domestic resources.

SOME NONTRADITIONAL MINERAL RESOURCES

New Type of Mineral Deposits

New type of mineral deposits refers to a kind of mineralization unknown so far, but such deposits to be discovered might initiate a great change both in geological research and in economic development. The potential discovery of new ore deposits is actualized by means of breaking away from the traditional conception of geology, since the creativity is the dynamics of development (FIGNR, 1998). For example, diamonds have been found in kimberlite and K-Mg-bearing porphyry, but some micro-grains of diamond are successively found in super-high pressure metamorphic belts among collision zones between plates in recent years. This discovery, reported in China (1997) and western Norway (1997), open a slit of light for us to locate the diamond (Paul, 1998). A researcher (1996) cited that the 20th century was the end of diamond found in kimberlite. On the other hand, the diamond may also be located in the super-high pressure metamorphic belts and in the lamprophyre deposits.

New Scope of Mineral Resources

A lot of new scopes of mineral resources have been found in the past years, and more new scopes will be verified in the future with the technological progress and the increasing human needs, as can be illustrated with the two examples.

Now it is time for us not only to try to find resources in earth land, but also to locate the mineral resources in the ocean that has a bright future in the exploration of mineral resources (Chen, 1997). During 1872 to 1876, more than one century ago, as we know, English discovered at first polymetallic nodules at the bottom of the Atlantic Ocean. Up to 1960s, some countries such as USA, UK, Japan, France, Russia and Germany, investigated and located some polymetallic nodules in the middle and eastern Pacific Ocean. During 1970 to 1980, some prolific polymetallic nodules were determined. After the investigation, we have basically understood the distribution of polymetallic nodules, and its relationship with benthal physiognomy, sedimentary types, geological structure and floor volcanism. According to the statistical research, about 1 500 thousand million tons of polymetallic nodules whose renewable resources include about 20-50 thousand million tons of Cu, Ni, Co, and about 6 000 thousand tons of polymetallic nodules are deposited per year only in the Pacific Ocean. The resources in the ocean, much more than those in the land, can be sustainably used for tens of years for the economic development.

On the other hand, the artificial deposits referring to gangues of large mines have become a new kind of resources utilized on the present condition of techniques and economics. Now, the less high-grade ores we can mine, the more gangues we can obtain. The gangues that have accumulated year by year bring us some environmental problems we have to face and to solve. In a smelting plant, for example, about 30-100 tons of gangues are generated when 1 ton of metal are produced at the same time. In this case, we will have to mine much more gangues than we have now if the grade of ores is decreasing constantly in the future. On the other hand, the upgrading of the mining technique and economics is beneficial for us to appraise gangues of a large mine again.

New Depth of Mineral Deposits

The exploration of deeper part of some mineral deposits is useful and economical method for increasing the reserves in large mines. According to a report, the deepest silo is about 4 117 m in a gold deposit of South Africa, whose gold reserves reach about 4 750 tons after prospecting the depth of ore beds and can be mined for another 14 years. In Russia, the average depth of ferrous metal ores is about 600 m, and the nonferrous metal ores about 500 m (Смыспоь, 1997). The depth of silo can be drilled to more than 1 000 m, and will be up to 1 500-2 000 m. In the depth below the earth surface, are present a large number of Cu, Ni, Co and Au mineral resources forecasted.

New Techniques of Mineral Resources

The research on new techniques has widened the range for the utilization of lower grade ores and for the processing of complex ores that agree with the technical progress. For example, the economic grade of Cu for mining was up to 10 % at the start of the 19th century, 3.8 % at the start of the 20th century, and about 1 % at present. This progress is concerned with the comprehensive utilization of the ore deposits and elements, some of which belong to the nontraditional resources. The concept of regional industrial combination boundary refers to the emphasis of the comprehensive utilization of mineral resources on the optimization of industrial combination and structure in the whole region. Therefore, we must study not only new techniques of the comprehensive utilization of ore deposits, but also the regional condition of economics and industries in an integrated system of nontraditional resources.

New Utilization of Mineral Resources

With the development of society and economics, mineral resources are not used merely in the conventional sense. Some new-fashioned industries and technical needs call for mineral resources in different ways. For example, the demands for environmental protection need pumice to depollute radioactivity, and the placement of such natural sorbents as pumice and diatomaceous earth in the soil to separate the radioactive elements from the cycle of vegetation life. The new utilization of mineral resources, as we know, can be classified as the following eight categories: (1) replacement of heavy metals, (2) accretion of fuels, (3) accretion of cement, (4) magnetic resonance photo, (5) scrambler zone of super-conduction, (6) image storage, (7) transformation of light fiber and (8) fuel battery.

RECENT CUTTING EDGE OF NONTRADITIONAL RESEARCH IN CHINA

Distribution of Nontraditional Deposits and Their Metallogenic Model

The original types of ore deposits have been gradually identified with geological research, but some phenomena of ore-formation are ignored because of the levels of geological recognition in different stages (Shen, 1997). New discovery of nontraditional deposits may bring about great changes in geological research which not only develops metallogenic theories, but also generates economic benefits. As we know, the discovery of porphyry copper deposits has experienced a great reform, since the porphyry copper was once not a traditional deposit. In addition, such mineral deposits as the chromite in the orthomagmatic deposit to that in impregnation deposits, the Carlin-type gold deposits to the impregnation Au deposits, the diamond from kimberlite to super-high pressure metamorphic belt, and the lamprophyre show the similar features to that of porphyry. In China, therefore, the cutting edge of the nontraditional research is to locate new types of ore deposits, such as gold deposits in the Cambrian strata in western Shandong Province, and lower-grade chromite in Hebei Province. At first, the geological background of mineralization, the distribution patterns in space and geohistory, and their metallogenic model should be clarified in order to meet the increasing demand for the mineral resources used for the economical development of China.

Discovery and Exploration of New Types of Ore Deposits in Crisis Mines

According to statistics, 70 % of total amount of ore deposits were found near the outskirts of the known large mines in eastern China. On the other hand, it is necessary to have new discoveries around such large mines, so called crisis mines which have been mined for over tens of years. The research results show that the cutting edge of the nontraditional research includes two aspects as shown below: (1) Discovery of and research into new useful associated components in crisis mines. The ore deposits are mainly composed of a metallogenic series of metals or nonmetals, only some of which have been utilized in China. After a large-sized crisis mine is mined for a long time, its mineral reserves often run short. Therefore, based on the geological analysis and comprehensive utilization, the associated components may have new values on recent economic and technique conditions. A large Cu-Au ore deposit, for example, has been mined for Cu for a long time, but the component of Au has not utilized as gangue. After the exploration of its gangue and goaf piles, the Au reserves are easy to determine, whose economic benefit may be compared with that of the exploration and establishment of an Au mine. If the investigation covers a whole province or a whole country, some crisis mines will prolong their service life span, and the demand for such mineral resources will be partly met in the future. (2) Discovery of new types of ore deposits in crisis mines.In crisis mines, discoveries of new types of ore deposits are also very important because most ore deposits are mainly composed of a metallogenic series of metals or nonmetals in China. In our country, the production of mines was merely focused on a major type, which did not gain enough attention. As we know, some Skarn ores often have paragenetic relationship with porphyry ores and hydrothermal ores. Some of the ore types have been found, but some others may not, constrained by the corresponding research degree and recognition levels. Based on the modern metallogenic theories and further research data, it is possible to find new type large-scale ore bodies in crisis mines (Zhou, 1998). Gejiu cassiterite deposits in Yunnan Province, for example, were found in the oxidized-ore veins and layers at first. Then, the oxidized-ore banded, veinlet and stockwork zones were found. At last, the primary ores in contact zones were found, the production of which has expanded from the mere distilling of Sn to that of Sn, Cu, Th and polymetallic ores.

Development of Nontraditional Prediction Theory

The prediction of mineral resources is a complex problem. Especially the research on the nontraditional methods has been conducted for a century. As mentioned above, the geo-anomaly theory, not only suitable for nontraditional mineral resources, but also for conventional ones, has been developed to reveal essential rules of mineralization. The relationship between the geo-anomaly and ore-formation/ore-prospecting, a very complicated problem, deals with at least some major factors such as: (1) the development and evolution process of ore formation; (2) the burial condition and erosive extent of mineral deposits (bodies); (3) the mineral prospecting work and research extent; (4) the development level of the study of mineral deposits and mineral prospecting; (5) the development level of technology used in the area being prospected; (6) the characters of the geophysical field and the geochemical field of mineral deposits or bodies; (7) the time of the ore-formation and the extent of reformation after the formation. Because these factors occur in different situations, the nature, connection and distinction of the relationship between the geo-anomaly and ore forming are also different.

The relationship between the geo-anomaly and ore formation is obvious and hidden. The geo-anomaly that has the obvious relationship with the ore formation is often included in a coupling or telescopic relationship with geophysical and geochemical anomaly, providing the relatively reliable prognosis of mineral resources or mineral bodies. In general, the obvious types are shallowly buried in the underground mineral deposits, mineral bodies or mineral resources. The mineral-bearing formation has a considerable contrast with the geophysical field and (or) the geochemical field of the surrounding geological formation, which is characterized by a later ore formation and a strong remolding. As for the geo-anomaly that has the hidden relationship with ore formation, the relationship between the geo-anomaly and the geophysical and geochemical anomaly illustrates the following two cases. Firstly, in the anomaly zone, the geophysical and geochemical anomalies coupled with the geological anomaly are absent. The cause for the formation of the previous hidden anomaly is that the ore body is deeply buried where the ore body has a minor difference in physical property from its surrounding rock. Secondly, in the geological background field are present the variations in geophysical and geochemical anomalies, which can not be explained at present due to the shortage of proficiency in working and cognitive levels.

Now, we are developing this theory in more and more detail, and we invite you to join our work!