## 3 Suichang Gold Mine Shrinkage Method to Filling Method Case
### Economic Benefits of Transformation  
Taking the test mining area in the middle section of the V-1 ore body of Suichang Gold Mine from +180 m to +260 m as an example, the expected economic benefits brought by adopting the mechanized upward horizontal layered filling method are divided into the following: labor cost, concrete construction cost, increased mining cost due to depleted ore, reduced lifting and transportation cost, reduced beneficiation cost, direct economic benefits created due to grade enhancement and increase in the amount of metal, and the equipment purchase cost and mining calibration engineering costs. After the transformation, due to the adoption of mechanized equipment, the operating personnel are reduced to 70% of the original, and the labor cost is reduced; through the reasonable allocation of the ratio of high and low intensity filling body, the filling cost is also reduced after the transformation, compared with the replacement of the original high intensity filling body of the mining pillar mining of the shrinkage method. The dilution rate is reduced from 40% to 10%, and therefore, the mining cost, lifting and transportation cost, and the cost of beneficiation is reduced; the rate of dilution and loss rate is reduced, and the amount of metal recovered is increased and good benefits are created. Only in the two items of equipment purchase and development engineering is the cost increased compared with the shrinkage method. Overall, after the transformation of the mining method, the total cost saving and revenue increase is 18,151,000 RMB (see Table 1 for specific details). In China, many mines facing mining difficulties similar to those of the Suichang Gold Mine. This is because China's mineral resources are dominated by small and medium-sized deposits, of which 65.7% are small gold deposits, 88.4% are small copper deposits, and 95.2% are small and medium-sized iron ore deposits. In the face of these mining difficulties, many mines actively seek to transform and adopt the backfilling method, which has achieved significant technological progress and economic benefits. The Dadiangou Gold Mine is one of the examples of successful transformation. Due to the fragmentation of the ore body, the mine faces problems such as poor mining technical conditions, large loss rates and dilution rates, and poor stope operation safety conditions. Through the transformation from the shrinkage method to the horizontal layered filling method, the Dadiangou Gold Mine successfully controlled the loss rate below 5% and the dilution rate below 8%. At the same time, this transformation measure has brought significant economic benefits, with an annual output value of 35.5956 million RMB and an annual net profit of 26.6967 million RMB. In addition, the Daliuhang Gold Mine in Penglai City, Shandong Province has also increased its stope production capacity to 60.32 t/d by transforming the shrinkage method to the backfilling method, reducing the ore dilution \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Factor** & **Shrinkage** & **Upward Horizontal Slicing** & **Benefit** \\  & **Method** & **Filling Method** & **Value** \\ \hline
1. Labor costs & 400 & 280 & 120 \\ \hline
2. Concrete construction costs & 237.7 & 191.0 & 46.7 \\ \hline
3. Mining costs due to dilution & 219.2 & 130.0 & 89.2 \\ \hline
4. Lift transportation costs & 151.6 & 104.2 & 47.4 \\ \hline
5. Benefication costs & 2888.0 & 1986.1 & 901.9 \\ \hline
6. Direct economic benefits of increased metal volume & 31,752.4 & 32,755.1 & 1002.7 \\ \hline
7. Equipment acquisition costs & 167 & 407 & \(-\)240 \\ \hline
8. Costs of the development engineering & 266.5 & 419.3 & \(-\)152.8 \\ \hline Total cost savings, revenue enhancement & & & 1815.1 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Analysis of direct comprehensive economic benefits of Suichang Gold Mine test quarry (unit: RMB 10,000). loss to 8% and 12%, respectively, and increasing the economic benefits of a single stope by 760,000 RMB.