Prophecy Development: Up to 64.39 Percent Silver Recovery From Pulacayo Tailings

Prophecy Development Corp (TSX:PCY) has received results from preliminary metallurgical test work on samples from various tailings piles at its Pulacayo project.
As quoted in the press release, summaries of metallurgical tests included:

Pulacayo Tailings 2 (head grade: Ag 165 g/t, Zn 0.38% and Pb 0.36%):
A bulk flotation test was done in order to obtain a concentrate with recovered silver, lead and zinc bearing minerals. The recovery of silver from this test reached 72.79% and the final concentrate grade assayed Ag 270 g/t, 0.36% Pb and 0.38% Zn. A significant amount of pyrite was floated together with the valuable minerals. A differential flotation test was performed and the lead final concentrate assayed Ag 3,765 g/t and Pb 10.02%. The recovery of the silver in the lead final concentrate reached 64.39%. The sample contained clay which may have decreased the recovery of metals. The test is considered somewhat successful because potentially saleable concentrate was obtained at an acceptable recovery level for silver. Control of the pyrite and clay may increase recoveries to make a saleable product.
Pulacayo Tailings 3 (head grade: Ag 350 g/t, Zn 0.19% and Pb 0.98%):
A bulk flotation test was done in order to obtain a concentrate with recovered silver, lead and zinc bearing minerals. The recovery of silver from this test reached 67.81% and the final concentrate grade assayed Ag 550 g/t with insignificant amounts of lead and zinc. A significant amount of pyrite was floated together with the valuable minerals. A differential flotation test was performed and the lead final concentrate assayed Ag 1,625 g/t and Pb 7.08%. Silver recovery reached 54.23%. The silver appears to be in the native state which may be a reason for the poor response of the sample to differential flotation testing. It is recommended to carry out further mineralogical studies and perform leach testing on the sample to possibly improve the recovery of silver.
Differential flotation tests were performed on the remaining 4 samples (Pulacayo Tailings 1, Pero Tailings 1, Pacamayo Tailings 1 and Paca Tailings 2). The summary of the tests results is given below:
Pulacayo Tailings 1 (head grade: Ag 98 g/t, Zn 0.21% and Pb 0.26%):
The lead final concentrate assayed Ag 480 g/t, Pb 0.29% and Zn 0.21%, and silver recovery reached 1.68%. Although depression of pyrite was good, the test failed to produce sealable concentrate and acceptable silver recovery. The sample contained moderate amounts of pyrite and clay and the silver appears to be in the native state which may be reasons for the poor response of the sample to differential flotation testing. It is recommended to carry out further mineralogical studies and perform leach testing on the sample to possibly improve the recovery of silver. Also, recoveries could increase if normal methods are used to control the pyrite and clay.
Pero Tailings 1 (head grade: Ag 220 g/t, Zn 0.41% and Pb 0.23%):
The lead final concentrate assayed Ag 2,830 g/t and Pb 20.76%, silver recovery reached 3.28% and lead recovery reached 14.42%. The test produced low recovery of silver and lead, mainly due to a significant amount of pyrite in the sample which was floated together with the valuable minerals. Also the silver appears to be in the native state which may be a reason for the poor response of the sample to differential flotation testing. It is recommended to carry out further mineralogical studies and perform leach testing on the sample to possibly improve the recovery of silver.
Pacamayo Tailings 1 (head grade: Ag 370 g/t, Zn 0.26% and Pb 2.05%):
The lead final concentrate assayed Ag 2,800 g/t and Pb 38.88%, silver recovery reached 13.38% and lead recovery reached 22.24%. The zinc final concentrate assayed Ag 1,960 g/t and Zn 46.01%, silver recovery reached 3.45% and zinc recovery 41.73%. The test produced low recovery of silver and lead, mainly due to a significant amount of pyrite in the sample which was floated together with the valuable minerals. The sample also contained a moderate amount of clay and the silver appears to be in the native state which may be reasons for the poor response of the sample to differential flotation testing. It was recommended to carry out further mineralogical studies and perform leach testing on the sample to possibly improve the recovery of silver. Also, recoveries could increase if normal methods are used to control the pyrite and clay.
Paca Tailings 2 (head grade: Ag 140 g/t, Zn 0.26% and Pb 0.39%):
The lead final concentrate assayed Ag 170 g/t and Pb 1.27%, silver recovery reached 4.18% and lead recovery is negligible. The zinc final concentrate assayed Ag 3,600 g/t and Zn 0.29%, silver recovery reached 59.73% and zinc recovery is negligible. This sample contained little pyrite but a moderate amount of clay. The test produced potentially sealable concentrate at acceptable recovery levels for silver yet recovery could be increased if normal methods are used to control the clay.
The detailed report along with the test’s flowcharts can be downloaded at www.prophecydev.com.

Click here for the full press release.