# Quality Evaluation of Wasteless Mining in Dongguashan Based on Intuitionistic Fuzzy Set and VIKOR
## 4 Case Study
### Evaluation of Wasteless Mining in Dongguashan Based on Intuitionistic Fuzzy Set and VIKOR
To verify the stability of the decision results, a value at every 0.1 in \(\
u\) \(\in\) [0,1] is taken to conduct a sensitivity analysis. The variation of Q with the decision mechanism coefficient \(\
u\) is shown in Figure 6 and Table 13 [16]. As shown in Figure 6 and the results of the sensitivity analysis in Table 13, the maximum grouping benefit is stable between class I and class II; when \(\
u\) = 0.9, the ranking order is I; when \(\
u\) is not 0.9, the ranking order is II. In summary, it can be seen that the VIKOR ranking method is relatively insensitive to the decision coefficient \(\
u\), and the decision results are stable. (5) Evaluation results of TOPSIS algorithm  
The VIKOR algorithm uses group utility values, individual regret values and trade-off values to rank the overall evaluation of the projects, while the TOPSIS algorithm ranks each project by the distance of positive and negative ideal solutions. Based on the overview of the Dongguashan Copper Mine in Section 4.1 and the analysis of evaluation criteria in Section 2.3, the final TOPSIS algorithm ranking results are obtained, as shown in Table 14.  
When the TOPSIS algorithm is used to evaluate the current status of wasteless mining at Dongguashan Copper Mine, its wasteless mining grade is finally rated as Grade II, which is consistent with the VIKOR algorithm. Although the evaluation results of the two evaluation methods are the same, the evaluation process is slightly different. In the TOPSIS algorithm, the overall evaluation is focused, and the project indicators are eventually ranked based on the Euclidean distance between the overall project indicators and the optimal ideal solution, but the worst indicators of the project are not reflected. In the VIKOR algorithm, the group utility value S is initially evaluated as grade I; due to the low resource recovery index of the Dongguashan Copper Mine, a low individual regret value R is eventually obtained, and the final compromise \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \(\
u\) & 0.1 & 0.2 & 0.3 & 0.4 & 0.5 & 0.6 & 0.7 & 0.8 & 0.9 \\ I & 0.1986 & 0.1987 & 0.1989 & 0.1990 & 0.1992 & 0.1994 & 0.1995 & 0.1997 & 0.1998 \\ II & 0.3971 & 0.3974 & 0.3978 & 0.3981 & 0.3984 & 0.3987 & 0.3990 & 0.3994 & 0.3997 \\ Q & 0.2393 & 0.2343 & 0.2293 & 0.2243 & 0.2193 & 0.2143 & 0.2093 & 0.2043 & 0.1993 \\ \hline \hline \end{tabular}
\end{table} 
Table 13: The variation of the value of Q with the change of \(\
u\). Figure 6: Q with coefficient \(\
u\) of decision mechanism. value Q is evaluated as grade II. In the vasteless evaluation, multiple aspects need to be considered, and the evaluation of the comprehensive mining level also needs to focus on the worst indicators. When the TOPSIS algorithm is used for evaluation, if the other indicators are excellent, and a few of them are poor, there will be excellent indicators that blur the worst indicators, thus affecting the overall evaluation results. Therefore, when considering the overall level and worst index of wasteless mining, the combination of the intuitionistic fuzzy set and the VIKOR evaluation algorithm, which integrates the SRQ three indicators, is more advantageous. (5) Comprehensive quality evaluation of wasteless mining of Dongguashan Copper Mine  
The above evaluation results show that there are inconsistencies in the evaluation grades of the three indicators of the SQR of the VIKOR algorithm. This is because the resource recovery rate of the Dongguashan Copper Mine is inferior, which determines the final individual regret value and affects the compromise value, Q. Since the resource recovery rate still cannot reach the optimal standard, the quality of the wasteless mining quality in Dongguashan Copper Mine is finally evaluated as grade II. The existing evaluation results have shown that the wasteless mining quality of the Dongguashan Copper Mine has reached the best level. However, the evaluation result of this study is level II, rather than the level I.