Thiosulphate Leaching (CleanEarth)

The process extracts the gold through the use of thiosulphate as the leaching lixiviant. The feed material is crushed and grinded to the required particle size. It is then dewatered to prepare for leaching. The thiosulphate reagent is mixed with water. The solution, ore and resin are added into tanks for leaching to take place. After a set time, the solution is screened to collect the resin and to filter the ore from the solution. This is followed by elution and precipitation of the gold for smelting .

Thiosulphate Leaching (CleanEarth) - Technology Assessment

Click any of the 'Assessment' data points in the table to learn more about the data or to contribute.

Categories	Sub-categories	Assessment questions	Assessment
Properties of the ore	Type of deposits	Is the technology suitable for hard rock deposits?	Yes
		Is the technology suitable for alluvial gold deposits?	Yes
		Is the technology suitable for eluvial gold deposits?	Yes
	Type of ore	Is the technology suitable for free milling ores?	Yes
		Is the technology suitable for oxide ores?	None
		Is the technology suitable for sulphide ores?	Yes
		Is the technology suitable for carbonaceous ores?	None
		Is the technology suitable for refractory ores?	Yes
		Is the technology suitable for sand rock bearing ore?	None
		Is the technology suitable for ore with clay material?	None
		Is the technology suitable for ore bearing nuggets?	None
		Is the technology suitable for ore in desert areas?	None
		Is the technology suitable for ore in wet conditions?	None
		Is the technology suitable for ore in coarse gravels?	None
		Is the technology suitable for ore in fine gravels?	None
	Grade/gold content	Is the technology suitable for high grade ores?	Yes
		Is the technology suitable for low grade ores?	Yes
	Grain size of the gold)	Is the technology suitable for fine grained gold?	None
		Is the technology suitable for course grained gold?	None
		Is the technology suitable for mixed fine and course material?	None
		Is the technology suitable for very/ultra fine grained gold?	None
	Feed volume (batch volume)	Is the technology suitable for large quantity of feed material?	Yes
		Is the technology suitable for small quantity of feed material?	None
Operationals requirements	Cost of equipment	Are the costs of procuring the technology affordable to artisanal miners?	No
		Are the costs of procuring the technology affordable to small-scale miners?	None
		Are the costs of operating the technology affordable to artisanal miners?	None
		Are the costs of operating the technology affordable to small-scale miners?	None
		Are the costs of maintanance and replacement affordable to small-scale miners?	None
		Are the costs of maintanance and replacement affordable to artisanal miners?	None
	Utilities and inputs required	Does the technology require water?	Yes
		Is the amount of water required suitable to processing by individual miners?	None
		Does the technology require electricity or power source?	None
		Is the amount of electricity required suitable to processing by individual miners?	None
		Does the technology requre diesel?	None
		Is the amount of diesel required suitable to processing by individual miners?	None
		Does the technology require reagents during processing?	Yes
		Is the amount of reagents suitable for processing by individual miners?	None
		Does the technology require any other infrastructure?	None
	Type of organisation	Does the technology allow operation by individual miners?	No
		Does the technology allow operation by group of miners?	No
		Does the technology allow operation by organisations?	Yes
		Does the technology allow operation by processing plants?	Yes
		Does the technology work only with a continous system?	Yes
		Does the technology work with batch and continous systems?	None
		Does the technology work only with a batch system?	None
Processing flowsheet and performance of the techology	Processing flow	Does the technology work as a standalone?	No
		Does the technology work as part of a process system?	Yes
	Gold recovery	Does the technology offer high recovery rates compared to the amalgamation process?	None
		What are the typical gold recoveries for this technology?	>90%
		Does the technology produce gold directly?	No
		Does the technology produce gold directly but in a different form to be converted to gold?	Yes
		Does the technology require other processes to recover the gold?	Yes
		Are there potential gold losses during processing with this technology?	None
	Processing time	Does the technology offer less processing time compared to the amalgation process?	No
	Tailings	Can the technology re-process tailings?	Yes
	Recovery of other minerals	Can the technology recover other minerals in addition to gold?	None
	Visual tracking and monitoring	Does the technology allow visual tracking and/or monitoring?	Yes
Local considerations	Availability of the equipment	Does the technology make use of equipment that is locally available?	No
	Availability of the inputs	Does the technology require inputs that can be locally sourced?	No
	Scalability of the technology	Can the technology be scaled up or down to suit the spectrum of ASGM activities?	Yes
	Adaptability of the technology	Can the technology be used in remote areas?	No
	Ease of use/learning (skills requirement)	Is the technology easy to use or learn?	Yes
		Does the technology require knowledge /skills on metallurgy to use?	Yes
	Capacity to maintain	Is the technology easy to maintain?	None
Health, safety and environment Risks	Health and safety hazards	Does the recovery of gold using this technology pose any health and safety hazards?	No
	Environmental risks	Does the recovery of gold using this technology pose any environmental risks?	No