## 4 Case Study
### Background
#### 4.1.3 Analysis of Mobile Phone Recovery Cost  
Recycling facilities are divided into three types: recycling station, detection classification station and professional processing plant. For the recycling station, we can cooperate with mobile phone sellers, so the fixed cost can be ignored. As for the detection and classification station and professional processing factories, China's mobile phone recycling is not centralized at present, and the corresponding facilities are rarely built. Based on the experience of the facility, the following assumptions are obtained.  
(1) The initial capital for the construction of a classified storage station is CNY 140,000, the daily classified storage cost of used mobile phones is 14 CNY/unit, and the fuel consumption of used mobile phones per unit volume is 41,000 J/kg.  
(2) The professional treatment plant needs special equipment and capabilities, so the initial construction fund is CNY 1.8 million. The unit disposal cost of the recycling processing station for a scrap treatment part is 7 CNY/unit. Waste fuel consumption per unit volume of processing is 89,000 J/kg.  
(3) The cost per unit distance in the transportation process of used mobile phones is 35 CNY/km\(\cdot\)ton. The carbon emission from the transport of used mobile phones per unit distance per unit quantity is 13 KG/km\(\cdot\)kg.  
Referring to the prices of mobile phone recyclers such as Huishubao, the recycling price of used mobile phones mostly fluctuates around CNY 200. In this paper, the purchase price is set at 200 CNY/unit. In addition, the transportation cost of mobile phone recycling is related to the transportation distance and the transportation weight as seen above. For this reason, the route distances between recycling areas in Jilin Province are shown in Table 7.  
Considering the carbon emissions in the transport and processing stages, the carbon dioxide emission coefficient of gasoline used in the disposal stage is 2.9, while the carbon dioxide emission coefficient of electric energy used in the processing stage is 0.9. The carbon emission standard of each type of waste mobile phone is obtained by using the carbon emission coefficient in the processing stage, as shown in Tables 8 and 9.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & **Gold** & **Silver** & **Copper** & **Palladium** & **Glass** & **Plastic** & **Metal** \\ \hline Processing cost & 41 & 15 & 10 & 36 & 0.2 & 1.4 & 5 \\ Selling price & 6002 & 1300 & 21 & 4004 & 0.5 & 3.7 & 12 \\ \hline \hline \end{tabular}
\end{table}
Table 6: Material treatment cost and price (unit: CNY/kg).  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**The Distance between** & **Chang** & **Ji** & **Si** & **Son** & **Tong** & **Yanbian** & **Bai** & **Liao** & **Bai** \\
**Cities (km)** & **Chun** & **Lin** & **Ping** & **Yuan** & **Hua** & **Autonomous Prefecture** & **Shan** & **Yuan** & **Cheng** \\ \hline Changchun & 0 & 122 & 116 & 168 & 264 & 443 & 263 & 112 & 350 \\ Jilin & 122 & 0 & 234 & 279 & 281 & 317 & 262 & 231 & 454 \\ Siping & 116 & 234 & 0 & 283 & 259 & 554 & 372 & 83 & 465 \\ Sonyuan & 168 & 279 & 283 & 0 & 431 & 578 & 429 & 278 & 191 \\ Tonghua & 264 & 281 & 259 & 431 & 0 & 479 & 60 & 182 & 614 \\ Yanbian & & & & & & & & & \\ North Korea & 443 & 317 & 554 & 578 & 479 & 0 & 416 & 529 & 760 \\ Autonomous prefecture & & & & & & & & & \\ Baishan & 263 & 262 & 372 & 429 & 60 & 416 & 0 & 254 & 611 \\ Liayuan & 112 & 231 & 83 & 278 & 182 & 529 & 254 & 0 & 459 \\ Baicheng & 350 & 454 & 465 & 191 & 614 & 760 & 611 & 459 & 0 \\ \hline \hline \end{tabular}
\end{table}
Table 7: Distance between cities in Jilin Province.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & **Whole Mobile Phone** & **Mobile Phone Motherboard** & **Mobile Phone Shell** \\ \hline Unit carbon emission & 1.9 & 13 & 19 \\ \hline \hline \end{tabular}
\end{table}
Table 8: Carbon emission from partial treatment of mobile phones (kg/unit).