Copper metallurgical slags: mineralogy, bio/weathering processes and metal bioleaching

CHAPTER 8: GENERAL DISCUSSION AND PERSPECTIVES ................................. 230
 
8.1
 
General discussion and perspectives ............................................................................. 232
 
8.2
 
Research overview and relevance ................................................................................. 234
 
8.2.1
 
A  key  role  of  phase  and  chemical  composition  in  mobility  of  metallic  elements 
harboured in slags ............................................................................................................... 235
 
8.3
 
Dumping case and issued contamination ...................................................................... 236
 
8.3.1
 
Soil-weathering case ............................................................................................ 238
 

---

xiv 
 
8.3.2
 
Phytomining (in situ removal, plant-based recovery) .......................................... 240
 
8.3.3
 
Bio-weathering ..................................................................................................... 242
 
8.4
 
Metal leaching and recovery ......................................................................................... 243
 
8.4.1
 
Bio-leaching (microbial-based recovery)............................................................. 243
 
8.4.1.1
 
Optimization of bioleaching conditions ....................................................... 246
 
8.4.1.1.1
 
Particle size ............................................................................................... 246
 
8.4.1.1.2
 
Liquid to solid ratio (pulp density) ........................................................... 247
 
8.4.1.1.3
 
Microorganisms ........................................................................................ 247
 
8.4.1.1.4
 
Growth medium composition (nutrient supply) ........................................ 248
 
8.4.1.1.5
 
Additional treatments ................................................................................ 248
 
8.4.2
 
Heap leaching ....................................................................................................... 249
 
8.4.3
 
Chemical leaching and metal recovery: opportunities and limitations ................ 250
 
8.5
 
Engineering applications ............................................................................................... 252
 
8.6
 
Cu isotopes in biogeoscience: current application and perspectives ............................ 253
 
8.7
 
Concluding remarks ...................................................................................................... 254