【Minerals News】Shandong Gold: Exploring the largest single gold deposit in China

On the morning of August 10, 2023, Shandong Gold Group held a press conference on the exploration results of Xiling Gold Mine in Jinan. On August 2nd, after being filed by the Shandong Provincial Department of Natural Resources, Shandong Gold Group discovered the largest single giant gold deposit in China - Xiling Gold Mine. On the basis of a detailed investigation and filing of 382.58 tons of gold metal in 2017, an additional 209.606 tons of gold metal were added, with a total of 592.186 tons of gold metal discovered and 590 tons of accompanying silver. The estimated potential economic value exceeds 200 billion yuan.

Xiling Gold Mine is located in Laizhou City, Shandong Province. The Jiaodong mineralization area is the third largest gold mine area in the world, and it is an important gold enrichment area and a national level integrated exploration area in China. Its gold reserves and production both rank first in the country. The resources of Xiling Gold Mine are mainly distributed between elevations of -1000 meters to -2500 meters, and it is currently the deepest single gold deposit discovered in China. The maximum strike of the ore body is 2085 meters, the maximum inclined depth is 2057 meters, the average thickness is 8.13 meters, and the thickest point reaches 66.52 meters. It has been found that the amount of gold ore is 147 million tons, with an average grade of 4.02 grams per ton. If the production scale of the mine is 3.3 million tons per year, it can serve the mine for more than 40 years.

According to reports, before 2010, the depth of exploration in China was only about one kilometer. From the perspective of the entire industry, the success rate of mineral exploration is very low, with only 1/300-1/500 of the target areas being converted into mines, and the success rate of gold exploration is about 0.7%. As a representative of deep mineral exploration, the discovery of Xiling Gold Mine is also a process of "from scratch to existence, from existence to excellence", continuously conquering deep mineral exploration technology.

In 1998, the State Council issued the "Measures for the Administration of Mineral Resource Mining Registration", "Measures for the Administration of Mineral Resource Exploration Blocks", and "Measures for the Transfer of Exploration and Mining Rights". After studying and analyzing previous geological data, Shandong Gold Group mastered the geological conditions and controlling factors of mineralization in the Sanshan Island fault zone area, and boldly determined that the main mineralization belt of Sanshan Island has significant prospecting potential along the northeast side, Applied for registration of the "Xiling Gold Mine Survey" exploration right in 2000.

Following the principle of "from known to unknown, from shallow to deep", from 2002 to 2007, Shandong Gold Group mainly studied and delineated prospecting target areas, organized professional technical personnel for exploration design. Despite multiple engineering verifications, only one borehole was found to have mineralized bodies, and the overall prospecting effect was not ideal.

From 2008 to 2009, Shandong Gold Group continued to search for and explore ore bodies. After comparing and analyzing geological data from similar deposits, it is firmly believed that the main fault zone of Sanshan Island still extends in this mining area, and it is speculated that larger ore bodies may be hidden in the deep. Finally, during the construction of ZK72-1 borehole, a gold deposit with a thickness of 23.98 meters and a grade of 3.14 grams per ton was seen at the -980m elevation, marking the beginning of a major exploration breakthrough at Xiling Gold Mine. Subsequently, the exploration work was systematically deployed, with 39 boreholes arranged and nearly 60000 meters of drilling work completed. More than 10000 rock and mineral testing samples were collected.

From 2010 to 2016, the project entered the detailed investigation stage, and the exploration level further improved. The area was densely drilled, with 48 boreholes arranged and a total drilling volume of over 70000 meters completed. The geological conditions, ore body characteristics, ore characteristics, and mining technical conditions of the mining area were basically identified. At this stage, 382.58 tons of gold metal were discovered, accompanied by 433 tons of silver.

From 2017 to 2023, the project entered the exploration stage. Shandong Gold Group has adjusted the exploration design scheme four times, deployed 93 densified boreholes, and completed more than 170000m of drilling work. To ensure the project schedule and quality, we have listed it as a key project and established a dedicated team to supervise the progress of the project. During the peak construction period, more than 20 drilling rigs were constructed simultaneously, and more than 400 professional and technical personnel were invested, providing a solid guarantee for breakthroughs in mineral exploration. At this stage, an additional 209.6.6 tons of gold metal were added.

According to Li Hang, Deputy Secretary of the Party Committee, Director, and General Manager of Shandong Gold Group, during this process, Shandong Gold Group has successively carried out the project of "Comprehensive Geological Research and Resource Prediction of the Ultra Deep Gold Concentration Area in the Northwest of Jiaodong", establishing a comprehensive mineralization model and exploration model for the Jiaodong Fault Metallogenic Belt; We have conducted research on the "three-dimensional comprehensive mineral exploration technology for integrating multiple geological information" and established new methods and technical routes for quantitative prediction of ore body positioning; We have independently developed a three in one integrated key technology that is suitable for deep drilling, including "extreme use of drill string depth", "salt resistant and high-temperature resistant drilling fluid", and "small diameter rope coring directional drilling". This ensures the successful implementation of deep drilling work and provides important scientific research support and technical support for further expanding mineral exploration achievements. The discovery and exploration of the Xiling gold mine also provide a reference and model for the deep exploration work and the expansion of existing gold enrichment areas in China, and also provide strong support for Shandong to build a "world-class gold production base" and consolidate safe and reliable strategic mineral resource reserves.

Data shows that in recent years, Shandong Gold Group's exploration footprint has spread to many regions in China, South America, Africa, and other regions, successfully exploring four super large gold deposits with over 100 tons, including Dongfeng, Xinli, Nanlu Xinmu, and Xiling, providing high-quality resource guarantee for building a "world-class gold production base". As of the end of June 2023, Shandong