PROCESS FLOWSHEET DESCRIPTION: Batch Gold Cyanidation-Leaching Plant.

ORE TREATED: Small tonnages of high-grade gold-silver ores and flotation or Jig concentrates amenable to cyanide treatment, used for treating as low as one ton of concentrates per day.

ADVANTAGES: Where the tonnage of ore or concentrates is too low for standard continuous cyanidation plants (usually less than ten tons per day) these simple and inexpensive batch plants allow the production of precious metal values in bullion form with low operating costs.

PROCESSING COMMENTS: The feed from the fine grinding circuit (some concentrates can be treated without finer grinding) is fed to a group of Super-Agitators, one of which is filling all the time. When an agitator has its predetermined charge, the feed is sent to the next agitator wrhich has previously been emptied at the completion of its treatment cycle and is. ready for refilling. The filled agitator is placed in operation and low-grade or mill solution added to bring the pulp to the proper operating level, then agitation is started and continued for a definite period. When agitation is completed, the unit is stopped, solids allowed to settle, and the solution decanted, clarified, and precipitated.

This agitator is again filled with low-grade solution, or barren solution available from the previous precipitation step, and agitated. The, solution available after this step may be precipitated if high enough in value or it may be stored and used for dilution in the grinding circuit. Again, this agitator is filled with barren solution and operated, stopped, decanted, and refilled with water for a washing step; after which the tailing is discharged. Clarification and precipitation is intermittent.