Revision History for Open-File Report 2012-1085

Donald I. Bleiwas

Estimated Water Requirements for Gold Heap-Leach Operations

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Posted online May 3, 2012

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Revised and reposted December 11, 2012

This is a revision of Open-File Report 2012–1085 done in response to suggested changes 
received from Mr. Mark Smith of RRD International Corp. 

(1)  The estimated upper range for solution lost as a result of evaporation was reduced to be 
more reflective of actual gold-leach operations based on comments provided by Mark E. Smith, 
President, RRD International Corp. 

(2)  The data presented in the tables were recalculated to include a 60-day leach cycle and more 
common solution application and solution loss variables. The text was modified to reflect 
these changes.

(3)  Figure 1 was modified to include the pumping of pregnant solution back to the heap.

(4)  The term “expandable” was replaced with “conventional” for one of three major types of 
heap-leach designs. “Conventional” is a more widely used term.

(5)  One of the conversions in the conversion table was transposed incorrectly.