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New Pacific Reports High Recovery of Silver From Various Metallurgical Processes for Sulphide, Transition and Oxide Styles of Mineralization From Silver Sand, Bolivia


VANCOUVER, British Columbia, Aug. 20, 2019 (GLOBE NEWSWIRE) -- New Pacific Metals Corp. (TSX-V: NUAG) (OTCQX: NUPMF) (the “Company”) is pleased to announce the final results of a preliminary metallurgical test work program for its Silver Sand Project. The Company is very pleased with the positive results achieved so far from the completed test work. The results suggest that the mineralized materials from the Silver Sand Project would be amenable to processing using conventional flotation or whole ore cyanidation at atmospheric pressure at large scale. This preliminary metallurgical program has demonstrated that good silver extraction rates are possible using these simple extraction methods and that further improvements and refinements should be possible in future programs after fine-tuning the various test parameters.


  • Composite samples of sulphide, transition and oxide mineralization were submitted for laboratory-scale rougher-scavenger flotation testing and this achieved up to 96.0%, 86.8% and 92.0% silver recovery respectively.
  • Composite samples of sulphide, transition and oxide mineralization were submitted for bottle roll cyanidation testing and this achieved up to 96.7%, 97.0% and 96.3% silver extraction respectively.
  • Samples of oxide mineralization were submitted for coarse column leach cyanidation testing and this achieved up to 82% silver extraction.
  • High recoveries achieved during cyanidation tests indicate that silver-bearing minerals within the sulphide and transition composite samples tested can be considered non-refractory in nature.
  • Composite samples were found to be mostly in the soft to medium grindability range with low to medium values of abrasion index.


Mineral Characterization

Size Fraction Assaying:

A photo accompanying this announcement is available at

Heavy Liquid Testing:

A photo accompanying this announcement is available at

Comminution Testing

Four geological domain composites were subjected to a program of comminution scoping tests, including Crushing Work Index (CWi), Bond Ball Mill Work Index (BWi) and Abrasion Index (Ai). Twenty-one samples were tested in total. CWi tests reported energy consumptions between 4.8 and 11.3kWh/t, while the BWi measurements were from 4.8 to 15.9kWh/t with only one sample above 14 kWh/t. Thus, the majority of the samples tested fell into the category of soft or medium competency level for crushing and grinding. These early indications suggest that relatively low capital and operating costs could be anticipated for any potential comminution circuits. The reported values of abrasion index of between 0.06g and 0.54g corresponds to low to medium abrasivity for these samples. Sulphide materials reported the highest values in the range of medium abrasion behaviour, while the oxides were generally the lowest.

Flotation Testing

Table 1 – Flotation Program Composite Details

Composite ID

Head Assay
Ag, g/tStot, %Cu, %Pb, %Zn, %
Oxide (Z1 FLOATMET 4)2010.120.0060.1080.003
Transition (Z1 FLOATMET 5)1231.010.020.3910.010
Sulphide (Z1 FLOATMET 6)1241.630.030.2170.812

Table 2 – Summary of Results for Rougher-Scavenger Test Work

CompositeFlotation conditions% Recovery
P80 (µm)Collector Mix/DosePulp pHFlotation GasAg, %Ssul, %
Sulphide (Z1 FLOATMET 6)74PAX, 45 g/t9.0Air96.098.4
Transition (Z1 FLOATMET 5)74PAX, 30 g/t + OX100, 15 g/tNaturalAir86.894.8
Oxide (Z1 FLOATMET 4)74PAX, 45 g/t + OX100, 20 g/t9.0N292.049.9

Bottle Roll Leach Testing

Table 3 - Bottle Roll Composite Details

Composite IDHead Assay
Ag, g/tStot, %Cu, %Pb, %Zn, %
LG Oxide (Z1 LEACHMET 1)290.150.0100.0620.008
HG Oxide (Z1 LEACHMET 4)1320.210.0090.0550.003
HG Transition (Z1 LEACHMET 5)1571.450.0400.1200.343
HG Sulphide (Z1 LEACHMET 6)1242.130.0310.0890.054

Table 4 - Bottle Roll Test Results Summary

Composite IDGrind

P80, µm
% Sol. StrengthConsumption, kg/tTempSparge Gas% Extraction
LG Oxide (Z1 LEACHMET 1)740.306.710.7859O281.648.5
HG Oxide (Z1 LEACHMET 4)740.303.940.7859O296.334.5
HG Transition (Z1 LEACHMET 5)500.309.780.7856O297.081.6
HG Sulphide (Z1 LEACHMET 6)500.3010.20.7957O296.773.7

Column Leach Testing

Table 5 – Column Leach Test Results Summary

Composite IDMesh of Grind
% Sol. StrengthSolution Rate
Consumption, kg/t% Extraction 
(calculated from PLS concs)
Z1 LEACHMET 1-12.70.407.06.31.475.345.8
Z1 LEACHMET 4-12.70.4010.08.61.684.445.1
Z1 LEACHMET 1-12.70.407.06.41.488.329.3
Z1 LEACHMET 4-12.70.4010.08.11.686.629.4

A photo accompanying this announcement is available at

A photo accompanying this announcement is available at


For further information, contact:

New Pacific Metals
Corp. Gordon Neal
Phone:(604) 633-1368
Fax:(604) 669-9387 

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this news release.


Certain of the statements and information in this press release constitute “forward-looking information” within the meaning of applicable Canadian provincial securities laws. Any statements or information that express or involve discussions with respect to predictions, expectations, beliefs, plans, projections, objectives, assumptions or future events or performance (often, but not always, using words or phrases such as “expects”, “is expected”, “anticipates”, “believes”, “plans”, “projects”, “estimates”, “assumes”, “intends”, “strategies”, “targets”, “goals”, “forecasts”, “objectives”, “budgets”, “schedules”, “potential” or variations thereof or stating that certain actions, events or results “may”, “could”, “would”, “might” or “will” be taken, occur or be achieved, or the negative of any of these terms and similar expressions) are not statements of historical fact and may be forward-looking statements or information.

Forward-looking statements or information are subject to a variety of known and unknown risks, uncertainties and other factors that could cause actual events or results to differ from those reflected in the forward-looking statements or information, including, without limitation, risks relating to: fluctuating equity prices, bond prices, commodity prices; calculation of resources, reserves and mineralization, foreign exchange risks, interest rate risk, foreign investment risk; loss of key personnel; conflicts of interest; dependence on management and others.

This list is not exhaustive of the factors that may affect any of the Company’s forward-looking statements or information. Forward-looking statements or information are statements about the future and are inherently uncertain, and actual achievements of the Company or other future events or conditions may differ materially from those reflected in the forward-looking statements or information due to a variety of risks, uncertainties and other factors, including, without limitation, those referred to in the Company’s Annual Information Form for the year ended June 30, 2018 under the heading “Risk Factors”. Although the Company has attempted to identify important factors that could cause actual results to differ materially, there may be other factors that cause results not to be as anticipated, estimated, described or intended. Accordingly, readers should not place undue reliance on forward-looking statements or information.

The Company’s forward-looking statements or information are based on the assumptions, beliefs, expectations and opinions of management as of the date of this press release, and other than as required by applicable securities laws, the Company does not assume any obligation to update forward-looking statements or information if circumstances or management’s assumptions, beliefs, expectations or opinions should change, or changes in any other events affecting such statements or information. For the reasons set forth above, investors should not place undue reliance on forward-looking statements or information.


This news release has been prepared in accordance with the requirements of NI 43-101 and the Canadian Institute of Mining, Metallurgy and Petroleum Definition Standards, which differ from the requirements of U.S. Securities laws. NI 43-101 is a rule developed by the Canadian Securities Administrators that establishes standards for all public disclosure an issuer makes of scientific and technical information concerning mineral projects.

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Figure 1
Silver Distribution by Size Fraction
Figure 2
Average Mass & Silver Recovery in the >2.58 kg/l Density Class
Figure 3
Column Leach Test Results Summary Graph
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