Technical Report on Supplementary Exploration

Abstract

This technical report discusses the importance and methodology of supplementary exploration in mining projects. Supplementary exploration is essential when significant discrepancies are identified in the initial geological exploration reports regarding ore body morphology, scale, occurrence, continuity, and quality, or when there are critical deficiencies in mining and processing conditions. It is also necessary when new ore bodies are discovered during the mining process. This report highlights the various scenarios that necessitate supplementary exploration, including insufficient original exploration, unclear ore body continuity, phased mining, complex hydrogeological conditions, engineering geological surveys for mine construction, insufficient slope stability research, and the need for detailed process parameters in mixed ore mining areas. By conducting targeted supplementary exploration, we ensure the reliability of geological data, supporting the efficient and safe development of mining projects.

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1. Introduction

In previous discussions, we covered "Pre-Mining Geological Evaluation." Today, we will address "Supplementary Exploration."

According to domestic industry practices, after an exploration report is submitted, no additional exploration report is compiled. Instead, a supplementary exploration report is used to reflect new geological survey results within the mining area.

The essence of supplementary exploration lies in conducting specialized geological surveys when significant discrepancies are found in the morphology, scale, occurrence, continuity, or quality of ore bodies, or when there are serious deficiencies in mining and processing technical conditions. This is also applicable when new ore bodies are discovered at greater depths or extensions during mining design, construction, and operation. Essentially, the initial exploration report does not meet the design and construction requirements.

From the above, it is evident that supplementary exploration ensures project construction quality and is not merely an expenditure.

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2. Targeted Supplementary Exploration Work

1. Insufficient Original Exploration:

?? - When the original exploration level is low, and the ore body’s scale, shape, thickness, and grade variations are unclear, further supplementary exploration is necessary to ensure reliable resource estimation and control the morphology and mineralization continuity of the ore body.

?? - Domestically, it is often found that exploration units do not connect ore bodies based on their occurrence but rather on grade, falsely enlarging smaller ore bodies. This leads to discrepancies between the reported and actual resources. The exploration rights holders (the clients) often lack the capacity for thorough review, and the approval process is merely procedural, resulting in significant deviations between the report and reality. Sometimes, this is a consequence of the pursuit of quick results.

?? - For example, in a detailed exploration report of a certain mine with an approved mining permit, there was no closed engineering control at depth and on both sides in the profile and projection map, and three exploration lines had no exploration work. A design institute placed the main shaft between two ore bodies. During shaft construction, rich ore was encountered. Through supplementary exploration and techno-economic evaluation, it was found that the safety pillar of the original shaft significantly impacted the ore, suggesting that relocating the shaft would be more appropriate, severely affecting the investment.

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2. Unclear Ore Body Occurrence and Continuity:

?? - When there are significant errors in the ore body’s morphology and resource estimation, thorough exploration and research are necessary to understand the patterns, modify the ore body connection scheme, and re-estimate the resources, especially for the first mining areas, to reduce interpretive ambiguity and enhance reliability.

?? - For example, a domestic phosphate mine, a sedimentary-layered deposit, had faults intentionally omitted during exploration for easier evaluation, falsely connecting ore bodies into folds when, in reality, faults disrupted the ore bodies.

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3. Phased Mining and Deep Ore Body Control:

?? - For mines with phased mining and low control levels of deep ore bodies, or new blind ore bodies discovered at depth, supplementary exploration is required to meet feasibility study and design needs for deep ore bodies.

?? - For example, in a porphyry-type mine with surface open-pit mining and underground mining at depth, the entire deposit has been explored, but the underground portion is only at a reconnaissance level, with limited drilling, controlling less than 20% of the resources. The ore grade tends to decrease with depth. Before transitioning from open-pit to underground mining, supplementary exploration and feasibility studies are necessary, along with resource-to-reserve conversion studies.

?? - Domestically, to expedite mining rights processing, early-stage exploration and research are often artificially reduced, correspondingly decreasing deep ore body exploration work.

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4. Significant Omissions in Hydrogeological and Engineering Geological Conditions:

?? - For mines with complex hydrogeological conditions, specialized hydrogeological supplementary exploration is necessary. For instance, a southern domestic phosphate mine with layered deposits controlled by synclinal structures and developed water-conducting faults, where surrounding rock formations are highly aquiferous (dolomite), requires systematic hydrogeological studies for pre-drainage mines.

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5. Engineering Geological Surveys for Mine Construction:

?? - This includes surveys for shaft engineering, concentrator engineering, etc.

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6. Insufficient Slope Stability Research in Open-Pit Mines:

?? - Significant impacts on design parameters necessitate slope stability studies and supplementary exploration.

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7. First Mining Areas with Significant Mixed Ores:

?? - For mines with substantial mixed ores, supplementary exploration focusing on mining and beneficiation process parameters (metallurgical geology), such as ore-rock boundaries, penetrability, explosibility, oxidation rate, mud content, selectivity, stripping ratio, harmful impurities, etc., is essential.

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Conclusion

Supplementary exploration plays a critical role in bridging the gaps left by initial exploration reports, ensuring the accuracy and reliability of geological data for mining projects. It is not merely an additional expense but a necessary step to verify and refine previous findings, address discrepancies, and adapt to new discoveries. By conducting targeted supplementary exploration, we can control ore body morphology and continuity, accurately estimate resources, and address critical issues in mining and processing conditions. This comprehensive approach helps to mitigate risks, optimize investment, and support the sustainable development of mining operations. The scenarios discussed, including insufficient original exploration, unclear ore body continuity, phased mining, complex hydrogeological conditions, engineering geological surveys, slope stability research, and detailed process parameters in mixed ore mining areas, underscore the diverse and essential applications of supplementary exploration. Implementing these strategies will significantly enhance the quality and success of mining projects.