Exploration companies have frequently found that governments in mineral-rich countries and states promise much higher yields than are actually available, writes A Shivkamal, and explains how GIS mapping can help with accuracy and also stem illegal mining.
When D C Durgabhoomi Tambang Ltd, an Indonesian mining firm owned by a Bangalore-based miner, applied for a coal block on island of Kalimantan, where the Indonesian government had offered several blocks for bids, the company was promised coal deposits of a very high calorific value. But rather than accepting the coal block on a lease, the firm decided to carry out a survey using Geographic Information System (GIS) for accurate reading of coal deposits and their calorific value. To the firm’s surprise, one month of GIS survey revealed that coal deposits of high calorific value were found only at the surface level whereas at depths beyond 50 m, the calorific value was not even average.
Had the company gone ahead and started commercial operations on the basis of the data provided by the Indonesian government, the coal block would have become economically unviable with unacceptable retuÂrns on investment (ROI). D C Durgabhoomi Tambang’s is not an isolated experience in the mining industry in deveÂloping countries where adoption of advaÂnced techÂnology for detection of mineral deposits accurately is still poor, owing to a variety of reasons.
“The situation in India is no different than Indonesia,†observed Pradeep K, Chairman & Managing Director, D C Durgabhoomi Tambang Ltd. “Here, we have to rely on physical survey maps produced by the government agencies 20 or 30 years ago. The maps are not updated. They may not even be accurate because back then technology was still not available to detect subterranean ore resources. We are not even sure if the deposits have increased because of mining in specific areas. It is imperative now for mining firms to set up a separate GIS wing in their Exploration and Prospecting Department. Otherwise, firms that venture into mining without conducting these GIS surveys at the fundamental level will end up regretting their decision later.â€
Finally, the company finalised two coal blocks in Indonesia and an iron ore mining lease in the neigÂhbouring Malaysia based on GIS surveys. Incidents of miners excavating low grade ore as against the promised high grade is rampant in all the iron ore-rich states, such as Karnataka and Orissa. Most of the miners are still relying on the survey maps created by the Department of Mines & Geology without bothering to authenticate the data through GIS mapping.
Faulty surveillance = Illegal mining
Illegal mining thrives largely because of lack of GIS-like scientific methods that help in prospecting. Such instances have led to large scale illegal mining in Karnataka between 2007 and 2010. One of the major reasons for miners to encroach upon government land beyond the lease area assigned to them is the inaccuracy of the data relating to the deposits. “Our survey maps showed deposits of high grade iron ore,†revealed a senior geologist at the Department of Mines & Geology, Government of Karnataka, and added, “but when the miners excavated deeper in their lease areas, the grade of the ore deteriorated. In order to meet the demand for iron ore in the international market and continue their business, miners were able to simply follow the high-grade iron ore veins that breached their lease boundary area into the adjoining government lands. More than 50 per cent of the lease area violations are attributed to this reason.â€
Finally, it seems the Indian government has woken up to the need for introducing technology in mining, from the prospecting phase till ore excavation, for a variety of reasons. GIS can help curb illegal mining; determine the deposits of a particular lease area, and aid scientific mining. The Mines & Minerals (Development & Regulation) Bill, 2011, lists out a series of requirements, including high-end technology for reconnaissance, prosÂpecting and excavating ore deposits, for both major and minor minerals. The role of GIS assumes significance under such circumstances, as it is considered one of the most advanced tools for accurately predicting the ore deposits. It is all the more important for India because hardly any area has been mapped using GIS to detect ore deposits.
A divining tool
GIS is a tool that provides software for determining, capturing, verifying, manipulating, querying, analysing, storing and displaying geospatial data with respect to a particular location, based on the computerised appliÂcations of cartography. Though the roots of GIS can be traced back to the 1960s, the widespread use of GIS and its applications gained importance in the last two decÂades because of the rapid advancements in computer hardware, operating system software, parÂticularly comÂputer-aided design (CAD), topography software and datamatics.
The applications of GIS commenced from urban projects—construction, city planning and traffic manÂagement, and were extended to other core sectors of the economy, such as oil and gas (O&G) exploration, forest wealth determination, and agriculture. Eventually, GIS also found its application in the mining sector.
Using GIS and CAD, it is easy to build the graphic version of the topography of an area, including the subÂterraÂnean features, to an extent of 100 m. Using preÂdeterÂmined GIS coordinates, geologists generate a 3-D moÂdel of the subterranean deposits of a particular mineral.
In countries that have a dominant mining economy, GIS is integral to core work. In the mining sector, GIS is treated as comprehensive technology specifically desiÂgned to compile, process, analyse, display, and archive exÂteÂnsive volumes of data.
A well-designed, implemenÂted, and supported GIS management structure can be used for mineral exploration, evaluate mining condiÂtions, evolve mining models, and display data relating to geoÂchemical or hydrological characteristics of an area. The technology has increasingly been playing an important role in applying for mining permits, assessing environÂmental impact, and scientifically excÂavating high grade ores that have commercial value.
GIS has effectively replaced old map-analysis proÂcesses, traditional drawing tools, and drafting and dataÂbase technologies, says B Manjunathan, CEO, Data Mining Spatial Services Ltd, a GIS technology provider. “Mining relying on linen, paper maps, old surveys records, drawings and by superÂimpoÂsing transpaÂrencies to create layers and compoÂsite images are considered arÂchaic. We recommend GIS for all mining firms that want to scientifically extract ore.â€
GIS integrates multiple ore exploration datasets such as geophysical images, radiometric surveys, drill-holes, geochemistry, geologic maps, and mineral deposits for optimisation of resources. GIS enables the geologists to estimate, manage, display, and analyse data, thereby resulting in successful, cost-effective discovery of new mineral deposits in new and existing lease areas.
Expert geologists observed that the mapping of the mineral potential at the prospecting level using GIS helps delineate areas with different probabilities of hosting specific types of minerals. The major benefits of developing mineral potential maps using GIS tools are: establishing the exploration conceptual model at the ore prospecting stage; building a spatial database of such terrains; spatial data analysis (extraction of evidence maps and assigning of weights); and eventually comÂbining the evidence maps to predict mineral potential of a given area.
Mine planners used GIS to establish the optimal location for exploration drifts, sublevels, elevators, crossÂcuts, ventilation shafts, air ducts and labour movement areas. For service and ancillary systems, GIS is used to ascertain the lowest-cost path for ensuring delivery of supplies to work areas, identity the closest facility and service range areas, assign proximity, and model inacceÂssible areas. The ore transporting conveyor belt system, ramps, shaft, winze, and haulways within a certain disÂtance of production centres can be planned using GIS.
A scientific approach to mining starts from using GIS at the reconnaissance and subsequent prospecting levels. During the development and production phases of a mining operation too, GIS comes in handy. Estimating the reserve or preparing the annual planned production or cost-per-tonne statistics can be linked directly to complementary geospatial technology, such as GPS. GIS is applied to both short-term and long-term scheduling to help optimise ore production and mining operations, and in the process achieve a higher ROI. Industry observers say the Indian mining industry is moving in the right direction, as several firms have now started GIS wings.
Experts believe there are plenty of benefits for the government if it establishes the mineral resources of the country using GIS. A GIS database helps the government agencies at the Centre and state levels and potential investors, particularly international mining giants, a clear first-hand look at a particular mining location (lease area), mining feasibility of the lease area, and possiÂble effects of the operations on the environment and local community—resulting in a broader underÂstanding of the project from all perspectives.
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