Did you know that tower cranes are used extensively in the gold mining process? Neither did I until Cranes Today magazine asked me to investigate for their September issue. The first step was to find out more about gold mining itself and the key processes that strip the gold from the source rock. Expert Paul Wheeler at the Cambourne School of Mines explained:
“The chemistry of the process is that gold has great affinity with cyanide, so if you add this gold with large surface area (after crushing) to react with the cyanide solution the gold will then form a solution as a cyanide complex. What you can then do is add carbon into this mix and the carbon has an even greater affinity with gold which gets loaded on to the carbon from the solution.”
The final outcome is a substance called loaded carbon which is then taken to an elution plant where an acid wash strips the gold from the carbon after which the smelting process can take place. “It is a big industrial chemical engineering process as we are talking about very large volumes of rock to get small quantities of gold.”
This big industrial process needs cranes to change the crushing plant, insert equipment, maintain the motors and gearboxes and tanks. Firms such as Liebherr, SA French and ETAC all took the time to tell me more about how their cranes are used in the mining industry and a full report will be in Cranes Today very soon.