Overview of rock gold deposit mining

Our country is the development and use one of the oldest gold in the world, but gold production of large-scale development or after the establishment of People's Republic of China. At present, it has formed a production base with Shandong, Henan, Heilongjiang and other provinces as the backbone, Hebei, Inner Mongolia, Jilin, Liaoning and other key gold-producing provinces, and the gold production industry has spread all over the country (except Shanghai) in more than 20 provinces and autonomous regions. According to statistics, as of 1988, 229 rock gold mines have been built and 209 mines are under construction. In 1988, the amount of gold produced was 8.38 times that of the early founding of the People's Republic of China. The mining technology has made great progress. The main production processes of the key rock gold mines have been mechanized, and various technical and economic indicators have been greatly improved. China's rock gold mines have made important contributions to the construction of the four modernizations.

The mineral properties, occurrence characteristics and mining technical conditions of the China Yanjin deposit are very complicated.

The rock gold deposit has the following characteristics:

1. The deposits are small in scale and widely distributed. According to the statistics of the mining area, large deposits accounted for 4.8%, medium-sized deposits accounted for 17.3%, and small deposits accounted for 77.9%.

Second, the deposit conditions are complex, the ore grade is low, and the distribution is uneven, and the stability of the ore is poor (see Table 1).

Table 1 Rock gold deposits are classified according to conditions

Third, the exploration level of the deposit is low. As of 1988, D-class accounted for 70% of all proven reserves.

The above characteristics of China's rock gold deposits determine its mining characteristics: the mine scale is small, mostly small and medium-sized. According to 1988 statistics, large mines only account for 5.24%, medium-sized mines account for 12.23%, and small mines account for 82.53%; The gold production is mainly rock gold. In 1987, the rock gold production accounted for 69.55% of the total gold; the rock gold mine was mainly underground mining, accounting for 82% of the mining volume, while the open-pit mine production only accounted for 18%.

The amount of rock gold mine open-pit mining in our country, although a slight increase in recent years, but the scale are small, such as wulaga gold, the gold warehouse, Yindongpo gold scale is 800 ~ 1200t / d, to be built in Guangxi The Gaolong gold mine is 500t/d. In addition, the Getang Gold Mine and the Bao'anwan Gold Mine Da'anhe Gold Mine, which have been put into operation or are about to be built, are small in scale and generally equipped. Develop a multi-use single-vehicle transportation mode. The perforating equipment uses 80-150mm down-the-hole drills (YQ-150 type, KQ-80 type), 200mm dentition drills for individual mines, and 1~3m ³ electric shovel or 5m ³ front loading machines for shovel loading. 8~12t domestic or imported dump trucks for transportation, 164054W bulldozers for auxiliary equipment. The mining process is mostly used for slow mining, and individual mines are used for mining (for example, Yangjishan Gold Mine). The height of the step is 8~10m, and the height of the step is 5m when mining with the front loading machine.

Open-pit mining of rock gold deposits, with the improvement of mechanization, the exploration of burial shallow large-scale rock gold deposits, can be expected to have a further development trend.

The underground mining of the rock gold deposit has greatly improved the mining technology and mechanization in the past ten years. The new mining method has been successfully tested successively, and the direction is simple, high efficiency, low loss and low operation, and safe operation. development of. According to the occurrence characteristics of the rock gold deposits and the technical and economic conditions of various places, the different types or combined mining schemes are tested and applied, which basically solves the problem of underground mining of different types of rock gold deposits.

Due to the limitations of deposit conditions and local conditions, the application of mining methods shows obvious regionality. For example, Shandong Province mainly relies on the retention method and filling method. These two methods account for 38% and 35%, Hunan Province. The main method is the wall-filling method, accounting for 64%. Henan Province is dominated by the comprehensive law and the comprehensive method of retaining minerals, accounting for 25% and 35% respectively. Inner Mongolia is mainly based on the wall-filling method, accounting for 48%.

It should be noted that due to the complex geological conditions of the rock gold deposits, the application of high-efficiency mining methods and large-scale mining equipment is greatly limited. The labor intensity of production is large, the labor productivity is not high (generally less than 10t/work·class), and the mining ratio is large (according to the statistics of 109 underground rock gold mines in 1990, the national average mining ratio is 685.7m/million), the ore loss is poor. Higher (the national average ore loss rate is 10% to 17.3%, the average depletion rate is 21.7% to 24.5%), and these problems are urgently needed to be further studied.