Over the last decade heap leaching with a cement binder has allowed the
economical leaching of low grade gold ores of less than 2 grams/tonne.
Despite the continued use of cement as an agglomeration aid, numerous
leaching operations continue to experience channelling and blinding
problems. This paper describes the development of polymeric agglomeration aids,
Extract Ore 9760 and 9960, which when used as a partial cement or lime
replacement can result in a higher rate of and/or a higher total gold
recovery in plant evaluations. Extract Ore in combination with cement
acts to produce a stronger agglomerate which results in reduced fines
migration during leaching and helps prevent blinding of the heap. Both of
these changes will give a more even flow of cyanide solution throughout
the heap and improve solution contact efficiency within the ore. Polymeric agglomeration aid programs are now being used by heap
leaching operations in three different countries. A summary of benefits
identified at some of these operations are presented in this paper.