11436 report01dec2013

8/13/2019 11436 Report01DEC2013

1/62

H AZEN R ESEARCH , I NC .

4601 Indiana Street Golden, Colorado 80403 USA Phone: (303) 27 9-4501 Fax: (303) 278-1528

www.hazenresearch.com

n Employee-Owned Company

November 26, 2013

E-mail Delivery

Mr. Marty HouhoulisSummit Mining International, Inc.8055 E. Tuffs Avenue, Suite 800Denver, CO 80237

Subject: Laboratory Study for Processing of 16 Ore Composite from the San Cristobal Mine, Bolivia

Hazen Project 11436Report and Appendices AD

Dear Mr. Houhoulis:

In September 2013, Summit Mining International, Inc. requested that Hazen Research, Inc. conduct aseries of experiments to investigate the amenability of the 16 Ore Composite to brine leaching andcyanide leaching as a means to recover silver. The composite was made from a blend of stockpile samplesand Toldos samples; both were used for previous test work conducted at Hazen. 1,2 A series of brineleaches was conducted to investigate the effect of pH, temperature, brine concentration, and brine salt

grade. Four cyanide experiments were conducted to measure the effect of cyanide concentration on silverrecovery. Results from all experiments were compared with previous work on other composites.

SAMPLE PREPARATION AND CHARACTERIZATION

The 16 Ore Composite was prepared according to the specifications shown in Table 1, which wasprovided by Summit.

1Timothy J. Cobb and Robert A. Reeves, Metallurgical Process Development Study, San Cristobal Mine,Bolivia, (company report, project 11436, Hazen Research, Inc., October 5, 2012).

2Pavel F. Belits, Continued Laboratory Study for Processing Ores from the San Cristobal Mine, Bolivia,(company report, project 11436, Hazen Research, Inc., August 7, 2013).

8/13/2019 11436 Report01DEC2013

2/62

Hazen Research, Inc. 2

Table 1. 16 Ore Composite Specifications

Client Description HRI Composite Makeup, wt%

Stockpile SamplesIntrusive Breccia 52960 6.25

Jayula Oxide 52963 6.25Mixed Oxide 53467-02 6.25Red Oxide 53467-03 6.25Silica Cap 52959 6.25Sulfide Dominant 52962 6.25Tesorera Oxide 52958 6.25Yellow Oxide 53467-01 6.25Subtotal 50Toldos SamplesToldos 1 53006 6.25Toldos 1 53541-13 6.25Toldos 2 53007 6.25Toldos 2 53541-14 6.25Toldos 3 53541-15 6.25Toldos 4 53541-16 6.25Toldos 5 53541-17 6.25Toldos 6 53541-18 6.25Subtotal 50

Total 100

The composite was prepared according to the flowsheet shown in Figure 1. The ground composite wasanalyzed with a Horiba LA-950S2 laser diffraction particle size analyzer. The 80% passing size (P 80) ofthe feed to the experiments was 48 m.

8/13/2019 11436 Report01DEC2013

3/62


Figure 1. 16 Ore Composite Sample Preparation Flowsheet

The complete analysis is located in Appendix A.

The chemical analysis of the feed is shown in Table 2. Composites from previous test work are includedfor comparison.

Table 2. 16 Ore Composite Head Analysis and Previous Test Work Head Analyses

DescriptionAg,g/t

Analysis, wt %Fe Cu Zn Pb S SO 4

2- S-2 (by difference)

16 Ore Composite 114 5.73 0.0105 0.138 0.407 0.88 1.27 0.46Stockpile 6 Ore Composite 176 3.01 0.0065 0.111 0.730 1.52 1.30 1.09Toldos 1 124 6.13 0.0085 0.094 0.158 0.44 1.01 0.10Toldos 2 78 6.35 0.0100 0.097 0.207 0.32 0.99 -0.01Toldos 3 46 6.17 0.0100 0.079 0.124 0.61 0.69 0.37Toldos 4 190 7.30 0.0405 0.073 0.136 0.70 1.03 0.36Toldos 5 78 10.60 0.0175 0.203 0.141 0.56 1.20 0.15Toldos 6 45 8.30 0.0095 0.055 0.049 0.46 1.01 0.12

The Toldos ores were generally lower in silver, total sulfur, zinc, and lead. The Stockpile ores weregenerally lower in manganese, iron, and copper.

8/13/2019 11436 Report01DEC2013

4/62


BRINE LEACH EXPERIMENTS

Previous laboratory test work has been completed on Stockpile ore blends and Toldos ores. Conditionswere selected from previous work for a baseline comparison in the new test work. Previous experimentswere conducted with a lixiviant consisting of 150 g/L NaCl and 10 g/L HCl with NaOCl as an oxidant.Those experiments were relatively successful; however, undesired amounts of lead, zinc, and iron wereleached. Experiments were conducted omitting the 10 g/L HCl, and lead, zinc, and iron dissolutionsdecreased, although the silver extraction was also reduced. Results of previous experiments with similarconditions are included for comparison in the following discussion.

Additional experiments were conducted to investigate the effect of increasing the brine NaClconcentration and of using locally available salt.

SETUP AND PROCEDURES

Figure 2 shows the apparatus used for the leach experiments. The leaches were performed in an agitated,2 L baffled glass resin kettle with a lid and cold water condenser. A sparge tube was added for testsemploying gases. A thermometer, pH, and electromotive force (emf) probes were used to maintain theselected conditions for each test. Small periodic samples were taken for kinetic evaluations, acid, andchlorine control over the 6 h run time. During the tests, bleach, NaOH, and/or acids were added tomaintain the specific conditions selected. Each test typically started with heating a predetermined amountof lixiviant in the resin kettle and adding enough solid feed to make a 45 wt% solids slurry. The lixiviantswere made specific for each test and consisted of NaCl and HCl. The NaOCl was used to maintain theemf in the slurry at approximately 950 mV (PtAg/AgCl electrode in saturated KCl). A sample of theresidue was submitted for silver assay by atomic absorption and other metals by inductively coupled

plasmaoptical emission spectroscopy. Standard Hazen laboratory procedures were followed for eachassay method.

8/13/2019 11436 Report01DEC2013

5/62


Figure 2. Apparatus for Leach Experiments

RESULTS AND DISCUSSION

Baseline experiments were conducted to determine if the 16 Ore Composite was amenable to the lixiviantdeveloped in previous test work. Results are shown in Table 3 and detailed results are in Appendix B.Results from previous experiments used for selecting conditions are also shown for comparison. The feed

ore used for the comparison was the 3 Ore Composite. This sample is described in a previously issuedHazen report. 3 The 3 Ore Composite was generally composed of ore collected by hand from stockpiles atthe Minera San Cristobal mine site and does not contain ore from the Toldos satellite deposit.

3Pavel F. Belits, Continued Laboratory Study for Processing Ores from the San Cristobal Mine, Bolivia,(company report, project 11436, Hazen Research, Inc., August 7, 2013).

8/13/2019 11436 Report01DEC2013

6/62


Table 3. Baseline Brine Leach Experiment Summary

Variable 10 g/L HCl pH 7 Ambient TemperatureTest Basis Comparison Basis Comparison Comparison Basis ComparisonNotebook 3678-14 3678-70 3678-22 3678-71 3678-73(-71R) 3678-15 3678-72

General Setup

Starting leach solution, g/LFeCl3 0 0 0 0 0 0 0HCl 10 10 0 0 0 0 0NaCl 150 150 150 150 150 150 150

Solids feed 1:1:1 mix 3678-68-0 1:1:1 mix 3678-68-0 3678-68-0 1:1:1 mix 3678-68-0Solids name 3 Ore Comp. 16 Ore Comp. 3 Ore Comp. 16 Ore Comp. 16 Ore Comp. 3 Ore Comp. 16 Ore Comp.Solids feed amount, g 960.24 454.56 960.07 454.56 454.54 960.12 454.55Residue wash procedure a RLLD RLLD RLLD RLLD RLLD RLLD RLLDTemp, C 50 50 50 50 50 22 Amb.Run time, h 6 6 6 6 6 6 6Pulp density, % solids 45.4 45.0 45.4 45.0 45.0 45.4 45.0Grind size, P 80 m 52 48 52 48 48 52 48End of Run Information

pH 0.24 0.27 6.95 6.98 7.07 6.99 6.99Free acid, g/L HCl 10 10.3 0 0 0 0 0emf, mV 9901,030 1,000 932 906 915 999 944100% HCl used, b kg/t 22.3 59.2 0.0 9.3 0.0 4.5 0.0100% NaOH used, kg/t 0 0 3.37 6.74 1.13 7.38 0.55100% NaOCl used, kg/t 18.6 13.3 15.2 58.0 7.9 31.1 7.0Brine at finish (NaCl), kg/t 130 141 128 117 157 99 158Metallurgical Balance (elemental), % Fe 94 94 105 93 95 94 97Zn 86 87 101 87 89 91 89Pb 94 87 104 89 93 96 93Ag 94 88 97 86 88 96 87Recovery, %

Element and basisAg calc'd head 65 70 62 65 64 55 60Ag feed/residue 67 74 64 70 68 57 65Fe feed/residue 16 31 -5 7 5 6 3Zn feed/residue 25 62 0 14 12 25 13Pb feed/residue 57 57 -4 11 7 4 8

aWash procedure key: RL or RB = re-pulped in lixiviant or brine, L = Lixiviant wash, D = DI water wash, B = Brine wash (brine at 150 g/L NaCl).b100% HCl used includes the acid in the lixiviant before the leach and the acid necessary to maintain the leach (not the acid used for re-pulping and

washing).

Generally, results compared well to the basis for each experiment. The 10 g/L HCl experiments both had

higher dissolutions compared with the neutral pH experiments. Higher temperatures did lead to bettersilver recoveries by about 510% and a higher acid concentration also increased the silver extraction;however, iron, lead, and zinc extractions also increased, which is an undesirable result because of theneed to separately extract these metals before the brine liquor can be recycled. Differences in dissolutionsand recoveries could be attributed to the different compositions of the feed ores. Results indicated that the16 Ore Composite could possibly be used to predict how other blends would perform under similarconditions. Generally, it appears that, considering the potential reduction in capital and operating costs,sufficiently high silver extractions can be achieved at the milder conditions of ambient temperature and

8/13/2019 11436 Report01DEC2013

7/62


neutral pH. It should be noted that Experiment 3678-71 was repeated due to the addition of excessNaOCl, which resulted in an unacceptably high NaOCl consumption. The repeated test achieved nearlyan equivalent silver extraction with a much lower NaOCl consumption.

Further experiments were conducted to observe the effect of increasing the NaCl concentration in the

brine as well as using a salt sample local to the ore bodies. Results are shown in Table 4 and detailedresults are located in Appendix B.

8/13/2019 11436 Report01DEC2013

8/62


Table 4. Brine Concentration and Salt Composition Experiment Summary

Variable Brine Concentration Local SaltNotebook 3678-74 3678-75 3678-76 3678-77

General Setup

Starting leach solution, g/L FeCl3 0 0 0 0HCl 0 0 0 0NaCl 175 200 225 225

Solids feed 3678-68-0 3678-68-0 3678-68-0 3678-68-0Solids name 16 Ore Comp. 16 Ore Comp. 16 Ore Comp. 16 Ore Comp.Solids feed amount, g 454.45 454.59 454.08 454.52Residue wash procedure a RLLD RLLD RLLD RLLDTemp, C Amb. Amb. Amb. Amb.Run time, h 6 6 6 6Pulp density, % solids 45.0 45.0 45.0 45.0Grind size, P 80 m 48 48 48 48End of Run Information pH 7.36 7.09 7.03 7.05Free acid, g/L HCl 0 0 0 0emf, mV 892 928 976 883100% HCl used, b kg/t 0 0 0 0100% NaOH used, kg/t 0.6 0.82 0.58 0.34100% NaOCl used, kg/t 6.9 6.3 12.2 6.3Brine at finish (NaCl), g/L 187 217 235 244Metallurgical Balance (elemental), %

Fe 102 102 102 102Zn 91 94 91 100Pb 96 95 96 96Ag 87 99 95 84Recovery, %Element and basis

Ag calc'd head 59 52 65 60Ag feed/residue 64 52 67 67Fe feed/residue -2 -2 -2 -2Zn feed/residue 12 8 11 11Pb feed/residue 5 6 4 4

aWash procedure key: RL or RB = re-pulped in lixiviant or brine, L = Lixiviant wash, D = DI water wash, B = Brine wash(brine at 150 g/L NaCl).

b100% HCl used includes the acid in the lixiviant before the leach and the acid necessary to maintain the leach (notthe acid used for re-pulping and washing).

Figure 3 displays brine concentrations and silver recoveries on a products basis.

8/13/2019 11436 Report01DEC2013

9/62

8/13/2019 11436 Report01DEC2013

10/62


Figure 4. NaOCl Consumptions and Silver Recoveries(Experiments 3678-72,-74,-75,-76,-77), Products Basis

For this comparison, the assumption is that the brine concentration has little effect on silver recoveries.Generally, as the bleach consumption increases, silver recoveries marginally improve.

An argument could be made that the brine concentration does have an effect on silver recoveries when

looking at the two experiments that consumed about 6 kg/t bleach (3678-75 and -77). Experiment -75had a starting brine concentration of 200 g/L NaCl, while Experiment -77 had a starting brineconcentration of about 225 g/L NaCl. Experiment -77 had a higher silver recovery; it also used salt localto the mine to create the brine, therefore it cannot be determined what caused the improved extraction.

CYANIDE LEACH EXPERIMENTS

A series of four experiments was conducted in October 2013 to measure the effect of cyanideconcentration on silver recovery from the 16 Ore Composite. Results of previous cyanide leachexperiments are used for comparison. 4

The leaches were conducted in 2 L, agitated glass resin kettles at ambient temperature. The 45% solidsslurry was adjusted to a pH of 10.5 before adding NaCN to the desired concentration. Kinetic sampleswere taken and used to maintain the NaCN concentration. Figure 5 shows the cyanide leach apparatus.

4Timothy J. Cobb and Robert A. Reeves, Metallurgical Process Development Study, San Cristobal Mine,Bolivia, (company report, project 11436, Hazen Research, Inc., October 5, 2012).

0

10

20

30

40

50

60

70

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0

A g

R e c o v e r y , %

NaOCl Consumption, kg/t

8/13/2019 11436 Report01DEC2013

11/62


Figure 5. Cyanide Leach Apparatus

RESULTS AND DISCUSSION

Cyanidation of the 16 Ore Composite resulted in silver recoveries similar to those of the brineexperiments. The 6 Ore Composite used for the comparative results did not contain any ores from theToldos deposit. Results are shown in Table 5 and detailed results are located in Appendix D.

8/13/2019 11436 Report01DEC2013

12/62

8/13/2019 11436 Report01DEC2013

13/62

8/13/2019 11436 Report01DEC2013

14/62


Another preliminary economic evaluation would be needed to quantify the differences in costs betweenthe two processes; however, it appears that the difference between the net revenues for the two processesis smaller.

Please contact me if you have any questions on the laboratory study results.

Regards,

Chandler R. CaldwellProject Engineer

CRC/gmr

xc: Charles W. Kenney, Hazen Research, Inc.

8/13/2019 11436 Report01DEC2013

15/62

Hazen Research, Inc.

APPENDIX A

Particle Size Analysis

8/13/2019 11436 Report01DEC2013

16/62

2013.10.03 08:43:40 2013.10.03 08:43:40 2013.10.03 08:43:40 2013.10.03 08:43:40

1 / 11 / 11 / 11 / 1

Median SizeMean SizeR ParameterChi SquareDiameter on Cumulative %

::::::::::::::

13.17801(m) 25.86740(m)8.0260E-2 0.047044(1)5.000 (%)- 1.7266(m)(2)10.00 (%)- 2.9479(m)(3)20.00 (%)- 5.1483(m)(4)30.00 (%)- 7.2200(m)(5)40.00 (%)- 9.6580(m)(6)60.00 (%)- 20.6526(m)(7)70.00 (%)- 34.3466(m)(8)80.00 (%)- 48.2299(m)(9)90.00 (%)- 66.1424(m)(10)95.00 (%)- 81.1573(m)

Horiba Particle Size

Project NumberSample NameID#Transmittance(R)Transmittance(B)Circulation SpeedAgitation SpeedUltra SonicDistribution BaseMaterialSourceTest or Assay. NumberRefractive Index (R)Refractive Index (B)

::::::::::::::

11436Ground Comp.201310030842741 85.6(%) 76.6(%)36OFFVolume

HRI: 53696-1Ground Comp.1.793,0.1,1.33[1.793,0.1,1.33( 1.793 - 0.100i),Water( 1.333)]1.793,0.1,1.33[1.793,0.1,1.33( 1.793 - 0.100i),Water( 1.333)]

q ( % )

q ( % )

q ( % )

q ( % )

Diameter(m) Diameter(m) Diameter(m) Diameter(m)

U n d e r

S i z e ( % )

U n d e r

S i z e ( % )

U n d e r

S i z e ( % )

U n d e r

S i z e ( % )

0.0 0.0 0.0 0.0

5.0 5.0 5.0 5.0

0.5 0.5 0.5 0.5

1.0 1.0 1.0 1.0

1.5 1.5 1.5 1.5

2.0 2.0 2.0 2.0

2.5 2.5 2.5 2.5

3.0 3.0 3.0 3.0 3.5 3.5 3.5 3.5

4.0 4.0 4.0 4.0

4.5 4.5 4.5 4.5

0.010 0.010 0.010 0.010 3000 3000 3000 3000 0.100 0.100 0.100 0.100 1.000 1.000 1.000 1.000 10.00 10.00 10.00 10.00 100.0 100.0 100.0 100.0 1000 1000 1000 1000 0 00 0

100 100 100 100

10 10 10 10

20 20 20 20

30 30 30 30

40 40 40 40

50 50 50 50

60 60 60 60 70 70 70 70

80 80 80 80

90 90 90 90

Remarks 1Remarks 2Remarks 3Remarks 4

::::

Ground Comp.HRI: 53696-1SonicationA DeWitt

Data Name201310030842741201310030842742

Graph Type Sample NameGround Comp.Ground Comp.

Median Size 13.17801(m) 13.14355(m)

Hazen Research Inc.


8/13/2019 11436 Report01DEC2013

17/62

8/13/2019 11436 Report01DEC2013

18/62

Brine Leach for Silver Date: 10/3/2013 Notebook: 3678-70Project 11436 Performed by: BS, KH

Purpose: To investigate the optimal leaching conditions of this brine leach for silver.This test uses 10 g/L HCl.

Procedure:Prepare the reaction vessel and equipment: get empty weight of 1 L reaction vessel with lid, clamps, and impeller.

1, 000 m L v es se l F re e a cid ti tr atio n on li q. S etup : e mf c ontr ol le r, p H pr ob e a nd me te r, the rm oc oup le a nd m ete r, m ix er , c ond ens er , and710 mL nominal vol tared conc. HCl bottle. Safety: perform in hood, solutions are toxic and corrosive.

emf (PtAg/AgCl sat. KCl probe) Prepare: 454.5 g of (moist) solids Actual wet mass: 454.6 g Actual dry mass: 449.8 g6 h run time pH monitoring Fill the reaction vessel with: 545.5 g of leaching solution, actual mass: 545.8 g

While heating and stirring , slowly add the prepare d solid s to the solution: 491 m LWhen temperature reaches target, mark start or zero time and take readings and sample.

0 g/L Fe(III) 0 g FeCl3 6H2 O Maintain emf at >900 mV by NaOCl controller (pump in below surface), get masses.150 g/L NaCl 150 g NaCl Maintain pH by pH reading and HClNaOH additions, get masses.10 g/L HCl 27.0 g 37% HCl Take samples and reading at 30 min, 1.5 h, 3 h, and 5 h; 30 mL slurry samples.

12.6 % NaOCl 22.7 m L 37% HC l Immediately filter s amples , put solids back into re ac tion ve ssel, replac e liq uor with brine solution.1.11density, g/mL Add 5 mL of conc. HCl to every kinetic sample (not PF or W).

Take another 10 mL slurry sample and filter immediately for Cl and FA, return liquid and solids.ID: 3678-68-0 Leach for 6 h. Submit liquors for Fe, Cu, Zn, Ag (by solvent extraction), Mn, and Fe.

45% solids 1.0% moisture Get mass of reaction vessel and filter hot. Keep PF . Separate filter paper and solids.48m P 2.77density (dry), g/cm Rinse out Buchner funnel with leaching solution. Wash filter paper with this solution and discard paper.

~325 mesh Keep emf high with drops of bleach. Repulp solids with the dirty solution. Filter. Keep W1 .

Wash solids in Buchner funnel with more leaching solution. Keep W2 . Wash with DI water. KeepW3 .

Spike with bleach to reach >900 mV before every kinetic sampling and final filtration.

emf measured with a PtAg/AgCl electrode in saturated KCl;Eh = emf + 199 mV at 25C.

Solids

General Setup MaintainMonitor

Cold water condenser

Leaching Solution 1 L of Solution

50C

Operating Data

Mass, g Vol, mL NaOCl, g Time, h FA HCl, g/L37% HClAdded, g

1 N HCLAdded, g

NaOH Added,g

~Cl , ppm Temp, C pH emf, mV

14.82 12.9 0 0.0 0.03 0 0 0 1050 50 1.89 55313.38 11.7 11.43 0.5 6.75 27.2 33.47 0 50100 50 0.34 6401,0508.60 7.6 18.26 1.5 11.0 22.28 0 0 ~200 51 0.18 1,0208.66 7.6 9.22 3.0 10.3 3.67 0 0

8/13/2019 11436 Report01DEC2013

19/62


Purpose: To investigate the optimal leaching conditions of this brine leach for silver.This test uses no HCl.





0 g/L Fe(III) 0 g FeCl3 6H2 O Maintain emf at >900 mV by NaOCl controller (pump in below surface), get masses.150 g/L NaCl 150 g NaCl Maintain pH by pH reading and HClNaOH additions, get masses.

0 g/L HCl 0.0 g 37% HCl Take samples and reading at 30 min, 1.5 h, 3 h, and 5 h; 30 mL slurry samples.12.6 % NaOCl 0.0 m L 37% HCl Immediately filter samples, put solids back into reaction vessel, replace liquor with brine solution.

1.09density, g/mL Add 5 mL of conc. HCl to every kinetic sample (not PF or W).Take another 10 mL slurry sample and filter immediately for Cl and FA, return liquid and solids.

ID: 3678-68-0 Leach for 6 h. Submit liquors for Fe, Cu, Zn, Ag (by solvent extraction), Mn, and Fe.45% solids 1.0% moisture Get mass of reaction vessel and filter hot. Keep PF . Separate filter paper and solids.

48m P 2.77density (dry), g/cm Rinse out Buchner funnel with leaching solution. Wash filter paper with this solution and discard paper.~325 mesh Keep emf high with drops of bleach. Repulp solids with the dirty solution. Filter. Keep W1 .



Solids


50CCold water condenser



Operating Data


1 N HCLAdded, g

NaOH Added,g


9.36 8.2 0 0 0 11.46 0 0

8/13/2019 11436 Report01DEC2013

20/62

8/13/2019 11436 Report01DEC2013

21/62














Solids


50CCold water condenser



Operating Data


1 N HCLAdded, g

NaOH Added,g


9.66 8.8 0 0 0 0 0 0 200 47 7.05 89010.45 9.2 0 2 0 0 0 5.58 50-100 52 7.03 85610.80 9.8 1.54 3 0 0 0 0.91 10-50 49 7.02 86910.39 9.4 2.73 5 0 0 0 0 100-200 50 7.03 9109.11 8.2 1.89 6 0 0 0 0 >200 51 7.07 915

Empty vessel, g 1,497.11 Wet solids, g 598.1 pH calibration 4, 7 check+Slurry start, g 2,497.35 Dry solids, g 449.3 emf check, mV 470 reads 468+Slurry end, g 2,457.66 NaOCl soln used, g 28.48

Primary filtrate, g 320.32 Wash 1 Wash 2 Wash 3 NaOCl used, g 3.59Primary filtrate, mL 292.00 Wt, g 526.1 548.4 463.7 Conc. HCl for lixiviant, g 0.00

Vol, mL 480 500 449 Conc. HCl used during run, g 0.00H Cl us ed , g 0 .00

1 N NaOH used during run, g 13.5N aO H us ed , g 0 .51

Analyses

Sample ID Ag diluted Ag undil Na Al S Mn Fe diluted Fe undil Cu Zn diluted Zn undil Pb diluted Pb undil diluted undiluted3678-70-zero 0.002 66.0

8/13/2019 11436 Report01DEC2013

22/62














Solids


Amb.Cold water condenser



Operating Data


1 N HCLAdded, g

NaOH Added,g


11.41 10.2 0 0 0 0 0 0 10-50 20 6.71 40913.29 12.0 10.66 1 0 0 0 1.03 ~50 21 7.07 78711.45 10.2 11.27 2 0 0 0 0 ~200 21 7.18 82014.00 12.5 2.99 3 0 0 0 1.64 200+ 20 7.06 89813.67 12.2 0 5 0 0 0 2 200+ 20 6.99 91913.30 11.8 0.10 6 0 0 0 2.72 100-200 21 7.36 892





Analyses


8/13/2019 11436 Report01DEC2013

23/62














Solids





Operating Data


1 N HCLAdded, g

NaOH Added,g


10.69 9.5 0 0 0 0 0 0 ~10 20 6.61 32711.03 9.8 14.86 1 0 0 0 0 100-200 21 6.66 85611.95 10.6 6.2 2 0 0 0 5.37 100-200 21 6.89 91212.03 10.5 0.06 3 0 0 0 2.46 100-200 20 6.9 89812.08 10.6 1.57 5 0 0 0 2 100-200 20 7.25 8919.81 8.6 0.05 6 0 0 0 0 100-200 20 7.09 928





Analyses


8/13/2019 11436 Report01DEC2013

24/62

Brine Leach for Silver Date: 10/31/2013 Notebook: 3678-76Project 11436 Performed by: BS













Solids





Operating Data


1 N HCLAdded, g

NaOH Added,g


13.69 11.8 0 0 0 0 0 0 ~10 21 6.48 36911.36 9.8 21.62 1 0 0 0 3.26 ~200 22 6.95 81813.50 11.6 22.24 2 0 0 0 0 ~200 21 7.43 94211.63 10.0 0 3 0 0 0 0 ~200 21 7.16 96810.58 9.1 0 5 0 0 0 2 ~200 21 6.97 98015.15 13.1 0.00 6 0 0 0 1.85 ~200 20 7.03 976





Analyses


8/13/2019 11436 Report01DEC2013

25/62


Purpose: To investigate the optimal leaching conditions of this brine leach for silver. Use client salt sample (HRI# 53551)This test uses no HCl.












Solids





Operating Data


1 N HCLAdded, g

NaOH Added,g


10.51 9.2 0 0 0 0 0 0 ~10 20 6.69 41110.80 9.4 4.02 1 0 0 0 2.20 ~10 20 7.00 77011.12 9.8 2.7 2 0 0 0 0 ~10 21 7.05 80211.82 10.3 4.81 3 0 0 0 0 50-100 21 7.18 79511.96 10.4 7.42 5 0 0 0 2 100-200 20 7.05 8349.29 8.0 3.81 6 0 0 0 0 ~200 21 7.05 883





Analyses


8/13/2019 11436 Report01DEC2013

26/62


APPENDIX C

Mineralogy Report

8/13/2019 11436 Report01DEC2013

27/62

n Employee-Owned Company

H AZEN R ESEARCH , I NC .

4601 Indiana Street Golden, Colorado 80403 USA Phone: (303) 27 9-4501 Fax: (303) 278-1528

www.hazenresearch.com

November 26, 2013

Mr. Marty HouhoulisSummit Mining International Inc.8055 E. Tuffs Avenue, Suite 800Denver, CO 80237

Subject: Silver Deportment in Feed and Brine Leach ResidueHazen Project 11436Report and Appendix

Dear Mr. Houhoulis:

This report summarizes the findings of a QEMSCAN-based study on the silver deportment in twosamples (16 Ore Composite and brine leach residue) from the San Cristobal Mine Project in the PotosiDistrict of Bolivia. The main objective of the investigation was to identify the mode of occurrence ofsilver-bearing minerals in both samples and the reason for the relatively poor silver extraction of 65%

(solids basis). The sample labels and chemical analyses are presented in Table 1. The feed to the leachhad a grind size of 80% passing 48 m.

Table 1. Sample Details and Chemical Analyses

Sample ID DescriptionMn Fe Cu Zn Pb Ag S tot

Analysis, %

3687-68-016 Ore Composite

HRI 53696-1P80 48 m

0.35 5.7 0.011 0.14 0.41 0.0114 0.88

3678-72 Solids Dry residue 0.34 5.6 0.009 0.12 0.38 0.004 0.74

SUMMARY OF SILVER DEPORTMENT

In the feed sample, silver occurs mainly as acanthite (Ag 2S). Silver was also observed at very low levels asmetallic silver, as a solid solution constituent in complex sulfides (sulfosalts), as chlorargyrite (AgCl), andas a silver-amalgam alloy (possibly Ag 2Hg 3). The largest liberated silver-bearing grain observed is 30 m

8/13/2019 11436 Report01DEC2013

28/62


in size. On average, silver-bearing grains are less than 5 m in size. More than 50% of the silver observedin the feed occurs as liberated grains or exhibits some degree of surface exposure. Another 25% is lockedin quartz, and the remainder occurs associated with or locked in iron oxide or iron hydroxide, feldspar,sulfosalts, pyrite, sphalerite, and galena.

The unleached silver observed in the residue is predominantly acanthite, locked in quartz. The averagegrain size of the locked silver is less than 5 m. A small portion also occurs as liberated acanthite,associated with iron oxide or iron hydroxide, and with unleached sulfosalts. Higher silver extractions canprobably only be achieved by finer grinding.

SAMPLE PREPARATION AND QEMSCAN ANALYSIS

Splits from each sample were mounted as 30 mm polished sections and analyzed by QEMSCAN in theFieldImage mode. Almost the entire surface of each polished section was scanned at an analysis pointspacing of 2 m. In total, data from 1,565 fields of view (each field was 585 m 2) were collected. In morethan 200 fields of view of the feed sample, silver-bearing grains were observed. The chemicalcomposition, grain sizes, mineral association, and liberation characteristics were manually verified andmeasured for the larger silver-bearing grains. Backscatter electron (BSE) images of some of the grainsobserved in the feed and the residue are presented in the appendix to illustrate the main modes ofoccurrence of silver.

The QEMSCAN FieldImage analysis mode also allows a quantification of the mineralogy of thesamples. These results are presented in the following section.

MINERAL ABUNDANCE ANALYSIS

Table 2 shows the results of the mineral abundance analyses of the two samples. The results presentedhere should be considered semiquantitative.

The concentration of silver-bearing minerals was measured at 0.08% in the feed and 0.03% in the residue.These are high estimates because of the silver-bearing mineral grains in general being smaller than thepixel size at the analysis point. The reduction from 0.08 to 0.03% reflects a change in concentration of64%, which correlates well with the reported 65% Ag extraction.

The main gangue minerals are feldspar (K-feldspar) and quartz, both are well liberated. Other gangueminerals observed are iron oxide or iron hydroxide, clays (probably kaolinite or dickite), muscovite and biotite micas, barium sulfate, other sulfates (probably jarosite and alunite), titaniumiron oxide, andtitanium oxide. Low levels of iron carbonate may be present. These are grouped in the iron oxidecategory in Table 2.

8/13/2019 11436 Report01DEC2013

29/62


Table 2. Mineral Abundance Analysis

Sample IDFeed Brine Leach Residue

HRI 53696 3678-72-solidMineral Analysis, %

Ag-minerals 0.08 0.03Quartz 27 26Feldspar 37 37Carbonate 0.2 0.1Fe oxide and Fe hydroxide 12 13Muscovite 1.9 2.2Biotite 0.8 0.7Clays 9.6 9.4Pyrite 0.2 0.2Sphalerite 0.09 0.0004Galena 0.15 0.01

CuSbFeZn(Ag)As sulfide 0.005 0.003Chalcopyrite 0.002 0.001Pb-Fe sulfate 1.1 1.2PbAlFeSrBaAsPSO 0.4 0.3Jarosite 0.2 0.2Alunite 0.8 0.8Mnminerals 0.8 0.8Barite 4.6 4.5Ba-bearing mineral 0.2 0.2Ti(Fe) oxide 1.1 1.1

As mineral 0.02 0.02Miscellaneous 0.9 0.8Unidentified 0.4 0.4

Total 100 100

In addition to the above-listed minerals, the sulfides pyrite, sphalerite, galena, chalcopyrite, and complexsulfosalts (containing mainly copper, antimony, iron, zinc, arsenic, and some silver) were observed at lowconcentrations.

The mineralogy of the manganese-bearing grains is complex. Iron, barium, zinc, lead, and potassium areassociated with the manganese-bearing oxides or hydroxides.

Lead is mainly observed in leadiron sulfate (possibly plumbojarosite) and in compound sulfates andphosphatesulfates, containing mainly lead, aluminum, iron, barium, strontium, and arsenic (possiblyminerals of the beudantite group).

8/13/2019 11436 Report01DEC2013

30/62


Arsenic occurs as arsenopyrite (FeAsS), as an unidentified ironarseniccalcium oxide or hydroxide, andas an unidentified ironarsenicbarium oxide or hydroxide.

The miscellaneous group in Table 2 mainly contains minerals like apatite, a chlorite-group mineral,zircon, fluorite, calcium sulfate, and other silicates.

The lower measured concentrations of the base metal sulfides in the leach residue indicate that sphalerite,galena, and chalcopyrite, and possibly the sulfosalts, have been partially leached. Pyrite appears to nothave been leached.

If you have any questions about this report, please contact me.

Regards,

Hanna HorschManager, Quantitative Mineralogy

HH/lmr

xc: Rick Kenney, Hazen Research, Inc.Roland Schmidt, Hazen Research, Inc.

8/13/2019 11436 Report01DEC2013

31/62


APPENDIX

BSE Images

Feed: Figures 116Residue: Figures 1726

8/13/2019 11436 Report01DEC2013

32/62

Hazen Research, Inc. A1

Figure A1. Silver-Bearing Particle in the Feed, Example 1

This composite sulfide particle, consisting of mainly chalcopyrite (cp) and pyrite (py), contains galena (high

BSE level, g) and very small inclusions of silver (Ag)- and antimony (Sb)-bearing minerals. The silver- and

antimony-bearing minerals (circled) are too small for detailed identification. The BSE signal of pyrite is

slightly lower than the signal of chalcopyrite.

Note that the length of the scale bar is 3 m.

cp pyg

Sb

Ag

8/13/2019 11436 Report01DEC2013

33/62

8/13/2019 11436 Report01DEC2013

34/62



This liberated particle (15 35 m) consists of acanthite (ac) and metallic silver (Ag).

ac

Agquartz

8/13/2019 11436 Report01DEC2013

35/62



This composite sulfide particle (25 30 m) consists mainly of a silver-rich mineral of the tetrahedrite

tennantite group (t1) and a copper-rich mineral of the same group (t2). The copper-rich mineral contains

lower levels of silver. The particle contains also galena (g).

t1

t2g

8/13/2019 11436 Report01DEC2013

36/62


Figure A5. Silver-Bearing Sulfate in Quartz in the Feed

This quartz particle shows secondary ironlead sulfates in pores inside the quartz particle. The energy

dispersive x-ray spectra (EDS) show low levels of silver. Because of the small sizes of the inclusions, it is

not clear if the silver is present as very small inclusions of silver minerals enclosed in the sulfates or the

silver occurs as a component of the sulfate. Galena (g) is also observed in the pores.

quartz

g

FePb(Ag) sulfate

FePb(Ag) sulfate

8/13/2019 11436 Report01DEC2013

37/62


Figure A6. Liberated Acanthite-Rich Particle in the Feed

quartz

Ag 2S

Pb-bearing sulfate

8/13/2019 11436 Report01DEC2013

38/62


Figure A7. Partially Oxidized Acanthite in the Feed

Acanthite (5 5 m) occurs as a core in what appears to be partially oxidized silver sulfide. The EDS

spectrum shows the presence of mainly silver with iron and low levels of oxygen and sulfur.

quartzbarite

Ag 2S

8/13/2019 11436 Report01DEC2013

39/62


Figure A8. Sphalerite (ZnS) with Silver-Rich Sulfosalt (s) in the Feed

EDS spectra performed on the sphalerite in this liberated mixed sulfide particle indicate the presence of

silver. It is believed that the silver signal originates from very small inclusions of acanthite in sphalerite.

sZnS

8/13/2019 11436 Report01DEC2013

40/62


Figure A9. Quartz Particle with Silver-Bearing Inclusions in the Feed

Like Figure A5, this is another example of possible replacement of primary sulfides by sulfates. Other, very

fine, inclusions in quartz may be leadiron sulfate.

Ag-bearing FePbK sulfatebarite

8/13/2019 11436 Report01DEC2013

41/62


Figure A10. Acanthite and Pyrite Inclusions in Quartz in the Feed

The small inclusions in quartz with a higher BSE signal (brighter) are acanthite. The maximum size of the

inclusions is 2 m.

8/13/2019 11436 Report01DEC2013

42/62


Figure A11. Liberated Acanthite and Acanthite with Clay in the Feed

Ag 2S

clay

8/13/2019 11436 Report01DEC2013

43/62


Figure A12. Acanthite with Sulfate in Quartz (q) in the Feed

A small inclusion of acanthite is associated with a lead-bearing sulfate. Other inclusions in quartz are

pyrite.

Ag 2S

PbBa(Ag) sulfate

pyriteq

8/13/2019 11436 Report01DEC2013

44/62


Figure A13. Acanthite with Galena (bright) in the Feed

Ag 2S barite

8/13/2019 11436 Report01DEC2013

45/62


Figure A14. Small Inclusions of Acanthite (brighter) in Lead-Bearing Barium Sulfate (s) in

Quartz (q) in the Feed

The acanthite inclusions are very small (less than 2 m). The largest acanthite inclusion in the sulfate is

marked by the arrow.

q

s

Ag 2S

s

8/13/2019 11436 Report01DEC2013

46/62


Figure A15. Pyrite and Silver-Containing Mineral in Quartz (q) in the Feed

In the contact zone between pyrite and quartz and enclosed in pyrite is a silverlead-bearing phase

(higher BSE signal). The rim and the inclusion are too small for a complete identification.

q

pyrite

Ag-bearing

8/13/2019 11436 Report01DEC2013

47/62


Figure A16. Small Acanthite Inclusions in Quartz (q) in the Feed

This quartz particle contains several inclusions of acanthite (less than 2 m), pyrite, and bariumleadiron

sulfate. Some of the inclusions appear to be below the surface of the particle cross section, resulting in

lower BSE signals emitted from these areas.

q

8/13/2019 11436 Report01DEC2013

48/62


Figure A17. Minute Inclusions of Acanthite (bright) in Iron Oxide or Iron Hydroxide

in the Residue

8/13/2019 11436 Report01DEC2013

49/62


Figure A18. Acanthite Inclusions in Sulfosalt (s) in the Residue

This particle is a copperantimonyarsenic sulfide, which may contain low levels of silver, with inclusions

of acanthite (higher BSE). The inclusions are less than 2 m in size.

s

Ag 2S

8/13/2019 11436 Report01DEC2013

50/62


Figure A19. Acanthite Inclusions in Iron Oxide (Fe) in the Residue

Ag 2SFe

feldspar

clay

clay

8/13/2019 11436 Report01DEC2013

51/62


Figure A20. Various Inclusions of Acanthite (circled) in Quartz (q) in the Residue

The inclusions appear to be a mix of acanthite, pyrite, leadbarium-bearing sulfates and leadbarium

ironsilver-bearing sulfates. It is possible that primary sulfides were replaced to form sulfates.

q

8/13/2019 11436 Report01DEC2013

52/62


Figure A21. Quartz Particle (q) with Iron Oxide or Iron Hydroxide (Fe) in the Residue

The circled area shows a pyrite inclusion with elevated silver. The small brighter area at the edge of the

pyrite is probably acanthite. Other inclusions are also silver-bearing. Also present are inclusions of lead

bariumiron sulfate.

q Fe

8/13/2019 11436 Report01DEC2013

53/62


Figure A22. Liberated Silver-Containing Sulfosalt in the Residue

This is a copperantimonyarsenicsilver-bearing sulfide.

8/13/2019 11436 Report01DEC2013

54/62


Figure A23. Silver-Bearing Inclusions in Quartz (q) in the Residue

The inclusions in quartz are pyrite, possibly acanthite, and leadbarium sulfate.

q

8/13/2019 11436 Report01DEC2013

55/62


Figure A24. Several Silver-Bearing Inclusions in Quartz (q) in the Residue

The inclusions are too small for complete identification. They are possibly a mixture of acanthite, pyrite,

and bariumleadiron sulfate.

q

8/13/2019 11436 Report01DEC2013

56/62

8/13/2019 11436 Report01DEC2013

57/62

8/13/2019 11436 Report01DEC2013

58/62


APPENDIX D

Cyanide Leach Data Sheets

8/13/2019 11436 Report01DEC2013

59/62

CN-1 Date:Test: 3751-65

Performed By: J SuterSample: HRI 53696-1

Sample Description: 16 Ore Comp.

Operating Data: Leach Conditions:Feed solids to leach, g: 200 Target pulp density, % solids: 45.0

Slurry water, g: 244 NaCN addition, g/L: 5Slurry weight, g: 444 Particle size P , m: 48

Temperature, C: Amb.Leach time, h: 6

Initial pH: > 11Initial DO, ppm: > 3

Initial NaCN, g/L: 5.00

Assay

Ca(OH) NaCN NaCN,g/L

InitialpH

AdjustedpH

DO,ppm

Conditioning10/7/2013 07:00 0 0.30 7.68 11.6510/7/2013 07:30 0.5 0.05 11.20 11.60 7.20

Cyanidation07:30 0 444 244 1.22 5.00 11.60 7.20

3571-65-1 08:30 1 457 257 20 0.24 4.08 11.313571-65-2 09:30 2 452 252 20 4.91 11.313571-65-3 11:30 4 426 226 20 0.08 4.64 11.373571-65-4 13:30 6 424 224 4.36 11.43 8.34

Note: Net sol'n vol is based on a specific gravity of 1.0DO = dissolved oxygen Total added, g 0 .35 1.54

CaO equivalent, g 0.26CaO requirement, kg/t 6

N aCN c ons umpt ion, kg/ t 2. 83

Products, Assays, and Results

Ag Fe Zn Pb Stot SO42- S2- (calc) Al Cu Mn Na

200 0.0114 5.73 0.138 0.407 0.88 1.27 0.46 7.54 0.011 0.35 0.3920 0.042 0.004 0.0191

8/13/2019 11436 Report01DEC2013

60/62









Assay


InitialpH

AdjustedpH

DO,ppm

Conditioning10/7/2013 07:00 0 0.30 7.81 11.4810/7/2013 07:30 0.5 0.05 7.19 11.65 7.11

Cyanidation07:30 0 444 244 0.49 2.00 11.65 7.11

3571-66-1 08:30 1 448 248 20 0.05 1.82 11.253571-66-2 09:30 2 436 236 20 0.04 1.82 11.213571-66-3 11:30 4 413 213 20 0.03 1.85 11.193571-66-4 13:30 6 420 220 1.61 11.22 7.96



N aC N c ons umpt ion, kg/ t 1. 27



200 0.0114 5.73 0.138 0.407 0.88 1.27 0.46 7.54 0.011 0.35 0.3920 0.035 0.005 0.0183

8/13/2019 11436 Report01DEC2013

61/62









Assay


InitialpH

AdjustedpH

DO,ppm

Conditioning10/7/2013 07:00 0 0.30 7.79 11.6210/7/2013 07:30 0.5 0.05 11.16 11.66 7.13

Cyanidation07:30 0 444 244 0.24 1.00 11.66 7.13

3571-67-1 08:30 1 450 250 20 0.05 0.8 11.223571-67-2 09:30 2 434 234 20 0.95 11.153571-67-3 11:30 4 406 206 20 0.02 0.9 11.183571-67-4 13:30 6 420 220 0.75 11.11 7.84



N aC N con sumpt ion , kg /t 0 .7 5



200 0.0114 5.73 0.138 0.407 0.88 1.27 0.46 7.54 0.011 0.35 0.3920 0.028 0.005 0.0177

8/13/2019 11436 Report01DEC2013

62/62





Slurry water, g: 244 NaCN addition, g/L: 0.5Slurry weight, g: 444 Particle size P , m: 48




Assay


InitialpH

AdjustedpH

DO,ppm

Conditioning10/7/2013 07:00 0 0.30 7.69 11.6510/7/2013 07:30 0.5 0.05 11.22 11.59 7.06

Cyanidation07:30 0 444 244 0.12 0.50 11.59 7.06

3571-68-1 08:30 1 450 250 20 0.03 0.39 11.253571-68-2 09:30 2 439 239 20 0.51 11.133571-68-3 11:30 4 412 212 20 0.47 11.083571-68-4 13:30 6 423 223 0.40 11.00 7.76



N aCN c ons umpt ion, kg/ t 0. 32



200 0.0114 5.73 0.138 0.407 0.88 1.27 0.46 7.54 0.011 0.35 0.3920 0.023 0 0.0154 0 0.09 0 0.012 0 0.20120 0.027 0 0.0165 0 0.07 0 0.013 0 0.26120 0.034 0 0.0199 0 0.07 0 0.015 0 0.322

145 0.031 0 0.017 0 0.08 0 0.015 0 0.218295 0.008 0 0.0037 0 0.02 0 0.005 0 0.099

196.85 0.0063 5.74 0.128 0.353 0.078 1.28 7.96 0.008 0.34 0.389


200.0 0.023 11.46 0.275 0.814 1.75 2.53 0.91 15.07 0.021 0.70 0.7720 0.0005 0.0000 0.0003 0.0000 0.0018 0.0000 0.0000 0.0000 0.0002 0.0000 0.0040

2 h kinetic 20 0.0005 0.0000 0.0003 0.0000 0.0014 0.0000 0 .0000 0.0000 0.0003 0.0000 0 .005220 0.0007 0.0000 0.0004 0.0000 0.0014 0.0000 0.0000 0.0000 0.0003 0.0000 0.0064

145 0.0045 0.0000 0.0025 0.0000 0.0116 0.0000 0.0000 0.0000 0.0022 0.0000 0.0316295 0.0024 0.0000 0.0011 0.0000 0.0059 0.0000 0.0000 0.0000 0.0015 0.0000 0.0292

196.85 0.012 1 1.30 0.252 0.695 0.15 2.52 0.00 15.67 0.0157 0.67 0.77

Total inputs, g 0 .023 11.460 0.275 0.814 1.750 2.530 15.070 0.021 0.696 0.771To tal ou tp ut s, g 0. 021 11.299 0 .257 0.695 0 .176 2 .520 15 .669 0.020 0 .669 0 .842

Accountability, % 92 99 93 85 10 100 104 96 96 109Extraction (calc'd head basis), % 41 0 2 0 13 0 0 22 0 9

Extraction (feed and residue basis) % 46 1 8 15 91 0 -4 25 4 1

3571-68-7 D ry res idue

3571-68-23571-68-3 4 h kinet ic3571-68-5 Final PF3571-68-6 Fina l w as h

Vol, mL

16 Ore Comp. Feed solids assay

Contained Mass, g

3571-68-1 1 h kinet ic

DryMass, g

Sample ID Sample Description

3571-68-7 D ry res idue

3571-68-3 4 h kinet ic3571-68-5 Final PF

Assay, wt% or g/L

3571-68-1 1 h kinet ic

3571-68-6 Fina l w as h

3571-68-2 2 h kinet ic

16 Ore Comp.

Operating Conditions

6 h Silver Agitation LeachHazen Project 11436

10/7/2013

DateClockTime

Elapsed

Time,h

Net

PulpWt, g

Net

Sol'nVol, mL

Reagents Added, g

Feed solids assay

SampleVol, mL

Sample ID Sample Description DryMass, g

Vol, mL

11436 report01dec2013

Documents