Ecuador: back on track to be a mining country

By:

Michael Potter, M.Sc.
mike_pttr@hotmail.com

Michael Potter is an independent Mineral Exploration geologist with a focus on hardrock and alluvial deposits. He has 35+ years of experience in exploring and mining with commodity experience in gold, uranium, Pt-Pd-Ni-Cu, coal, and diamonds across many international locations. Mr. Potter holds a M.Sc. and MBA and is a Qualified Person for NI43-101 and a Competent Person for JORC. He currently resides in Uruguay.

11-September-2017

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Summary

Traditionally, Ecuador has not been seen as a significant metal mining country. However, exploration during the 1990s and 2000s had defined several projects that by early 2008 were nearing the mine construction stage. Then, in April 2008, the Constitutional Assembly cancelled the existing mining law and, by so doing, halted all metal exploration and mine development in the country. Work was allowed to restart in November 2009. However, by then Ecuador was no longer regarded as a mining friendly jurisdiction, and it was not until 2013 that the government began taking action to restore Ecuador’s reputation within the mining industry. Now a series of new mines are coming on stream, and by the mid-2020s these could give Ecuador the annual capacity to produce about 120,000 tonnes of copper and 800,000 ounces of gold plus 3 million ounces of silver and 20,000 tonnes of zinc (Figure 1).

Figure 1: Ecuador – Potential New Mine Output 2018-2037 (2023-2030 averages: Cu ~ 120,000 tonne/yr, Au ~ 800,000 oz/yr, Ag ~ 3,000,000 oz/yr, Zn ~ 20,000 tonne/yr)

These metals, mostly in concentrate form, will come from two large-scale mines in the southeast of Ecuador and five smaller mines in the west and southwest of the country (Figure 2, Table 1, Plates 1-3). According to current plans, the output from these mines will decline after 2030 as the deposits are depleted. Fortunately, Ecuador has an established inventory of copper ± gold porphyry deposits under evaluation (Figure 2, Table 2, Plates 4-5), including the newly discovered, large, Alpala copper-gold porphyry system, which has still to deliver an initial resource. Some of these deposits should yield new, large-scale, long-life mines in time to maintain, or even increase, Ecuador’s copper output (and possibly also its gold output), perhaps for decades, after 2030. In contrast, the continued output of zinc, and to some extent silver, at 2020s levels will depend on the success of exploration for more volcanic-hosted, massive sulphide deposits in the west of the country.

Figure 2: Geological Sketch Map of Ecuador with the Locations of the Mining Projects and Mineral Deposits Listed in Tables 1 and 2

Table 1:   Mines Expected to Open in Ecuador Before 2023

PLATES 1-3

Plate 1: FRUTA DEL NORTE – Base Camp

(source: www.lundingold.com)

Plate 2: LOMA LARGA – Planned Underground Workings (source: INV Metals Inc., 2017)

Plate 3: ZARUMA GOLD PROJECT – Processing Plant (source: www.dynastymining.com)

 

 Table 2: Large Ecuadorian Mineral Deposits with Resources Estimated

PLATES 4: CANGREJOS – Core Drilling

Plate 4a: (left) Day Drilling (hole C11-31); (right) Night Drilling (hole C11-32). (source: author)

Plate 4b: (left) Recovering Core (hole C11-33); (right) Core Logging Shed. (source: author)

Plate 5:   APALA – Preliminary 3D Magnetic Model of Target Zone

 (source: Solgold plc, 2016)

History (1900-2016)

Ecuador has been a producer of gold since pre-Colombian times. However, output has generally been modest. Over the 25-year period 1990-2014 Ecuador produced an average of about 200,000 ounces of gold per year, with artisanal production and small mines providing most of the output (USGS 1995-2014). Nevertheless, in the past, Ecuador did have one large gold mine. During the first half of the 20^th century, the underground operation at Portovelo (Figure 2) produced about 3½ million ounces of gold and 12 million ounces of silver from the extensive, Portovelo-Zaruma, epithermal vein system (Spencer et al., 2002).

A few, small, base metal rich mines have also operated in Ecuador. Between 1941 and 1950 the Macuchi mine in the west of Ecuador (Figure 2) produced about 24,000 tonnes of copper and 100,000 ounces of gold from a volcanic-hosted, massive sulphide deposit with grades of about 5% copper and 7 g/tonne gold (Stoll, 1962). Then, from 1977 to 1981, the La Plata mine, located about 50 km north of Macuchi, produced 130,000 tonnes of ore containing about 4 g/tonne gold, 65 g/tonne silver, 4% copper and 7% zinc from a broadly similar type of deposit (Vachun, 2016).

In early 1981 a landslide revealed old Inca workings on the gold-bearing skarns at Nambija in the southeast of the country (Figure 2). Within two years 500 artisanal miners were working the site (Gemuts et al., 1992), and it is estimated that up until the year 2000 about 2½ million ounces gold may have been extracted from the numerous, small, generally unregulated, underground workings in the area (Porter GeoConsultancy, 2006a).

Modern, company-based, mineral exploration began in Ecuador shortly after the discovery of Nambija. Exploration continued through the 1990s and into the 2000s. As a result, by early 2008 all the deposits in Tables 1 and 2 (except Alpala) had been identified, even if no formal resource had yet been established. Furthermore, five projects (Mirador, Fruta del Norte, Quimsacocha [now Loma Larga], Rio Blanco and Dynasty’s Zaruma project) were approaching the construction decision point.

Then, on 18 April 2008, the Constitutional Assembly, which had been formed to rewrite Ecuador’s constitution, cancelled the existing mining law, revoked 80% of the existing mining concessions, suspended the other 20%, and stopped the issue of new mineral concessions (USGS, 2008). Immediately, all mineral exploration and development for metals in Ecuador came to an abrupt halt. A new Mining Act was passed in January 2009, but the regulations needed to implement it were not approved until November 2009 (USGS, 2009). At this point work could restart on those concessions still considered valid under the new law.

However, by this time confidence in Ecuador as a desirable jurisdiction for mineral exploration and development had collapsed. In 2008/2009 Ecuador was ranked the second worst jurisdiction in the world, at number 70 out of 71, on the Fraser Institute’s “Political Perception Index” (Fraser Institute, 2009), and in the following years the number of foreign mining and exploration companies active in Ecuador dropped from around fifty to about five (Cornerstone Capital Resources Inc., 2016).

While most overseas companies were leaving Ecuador, two foreign, state-sponsored organizations, CODELCO of Chile and a Chinese consortium composed of Tongling Non-Ferrous Metals Group and the Chinese Railroad Construction Corporation (TNFMG/CRCC) remained, and both organizations were eventually successful in obtaining important copper projects (Tables 1 and 2).

Kinross Gold Corporation, also, took a calculated risk on Ecuador. However that bet ultimately failed (Koven, 2013). In July 2008 Kinross acquired the Fruta del Norte gold deposit from its discoverer, Aurelian Resources, in a deal worth USD 1.2 billion. However, despite Kinross having once called Fruta del Norte “one of the most exciting gold discoveries of the past 15 years” (Reuters Market News, 2014), Kinross and the government could not finalise the terms of an exploitation contract, which would have included a 70% windfall tax. Consequently, Kinross abandoned the project in June 2013 and in December 2014 sold it to Lundin Gold Inc. for USD 240 million (Kinross Gold Corp, 2014).

Kinross’s departure seems to have spurred the government into taking action to restore Ecuador’s reputation as an attractive destination for miners and explorers (Jamasmie, 2017).

In June 2013 Ecuador revised its mining law (Garcia and Cazar, 2013). This revision introduced the concept of medium-scale mines to produce three production categories for industrial-scale mining. Each category has its own royalty regime (Table 3). However, only large-scale projects are required to negotiate a specific exploitation contract with the government and are subject to the windfall tax.

Table 3: Industrial-Scale Mine Production Categories and Conditions (based on data in Garcia and Cazar, 2013, and Schwartz, 2016).

Item	Small-scale	Medium-scale	Large-scale
Underground mine	≤ 300 tonnes/day	301 – 1,000 tonnes/day	>1,000 tonnes/day
Openpit mine	≤ 1,000 tonnes/day	1001 – 2,000 tonnes/day	>2,000 tonnes/day
Alluvial mine	≤ 1,500 m3/day	1,500 – 3,000 m3/day	>3,000 m3/day
Royalty	3% fixed	4% fixed	5-8%
Windfall tax	No	No	YES
Exploitation contract	No	No	YES

In 2014 Ecuador made several improvements to the local investment regulations (Córdova Unda, 2017). Then, in 2015, for the first time in its history, Ecuador established an independent Ministry of Mining in order “to incentivize and accelerate” the development of the mining sector and to transform it “into a pillar of the economy in the next 5-10 years” (Ministry of Mining, 2017). Finally, in 2016 Ecuador re-opened its mining register and began to issue new mineral concessions once again (Córdova Unda, 2017).

New Mines Coming into Production

In 2012 Dynasty Metals & Mining Inc. was the first company to open a mine under the 2009 law. In 2013 and 2014 this new underground mine in the old Zaruma goldfield produced an average of about 28,000 ounces of gold and 59,000 ounces of silver per year (Dynasty Metals & Mining Inc., 2016). Output slowed in 2015 and stalled in 2016. However, in early 2017 Dynasty began trucking ore from surface mining at the Dynasty Goldfield project (Figure 2) to its Zaruma plant (Dynasty Metals & Mining Inc., 2017). Taken together, the Zaruma and Dynasty Goldfield projects (Table 1) seem to have the potential to return Dynasty to, at least, its 2013 and 2014 level of output. Indeed, the preliminary assessment for Dynasty’s Zaruma project prepared by Procter et al. in 2014 considered the possibility of this single project producing 70,000 ounces of gold and 140,000 ounces of silver per year for at least 15 years.

The next new mine to come into production should be Junefield Minerals Resources’s medium-scale underground gold mine at Rio Blanco, to the west of Cuenca (Figure 2). Construction of the main access tunnel started in August 2016, and the mine is scheduled to open in late 2017 (Córdova Unda, 2017). The output from the mining of a sub-vertical set of epithermal quartz veins (Porter GeoConsultancy, 2006b) should be about 60,000 ounces of gold and 400,000 ounces of silver per year over a mine life of 7 years (Gowans et al., 2006).

Ecuador’s first large-scale mine is expected to enter production in 2018 (Córdova Unda, 2017). The TNFMG/CRCC consortium is building an openpit mine at Mirador in southeastern Ecuador (Figure 2). This mine is based on a slightly gold-rich, porphyry copper deposit located towards the northern end of the Zamora Batholith (Drobe et al., 2013). A feasibility study prepared in 2008 (Drobe et al, 2008) considered a processing rate of 30,000 tonnes per day of ore to produce about 200,000 tonnes per year of sulphide concentrate containing around 60,000 tonnes of copper, 30,000 ounces of gold, and nearly 400,000 ounces of silver over a mine life of 16½ years (Table 1). Moreover, in 2016 TNFMG/CRCC received a permit to double production to 60,000 tonne per day (Córdova Unda, 2017). Consequently, annual metal output should, in time, rise well above the amounts given above.

Ecuador’s second large-scale mine to enter production should be Lundin Gold’s underground gold mine at Fruta del Norte, 25 km south of Mirador (Figure 2). This world-class, high grade, epithermal gold deposit lies in a lens of Jurassic continental volcanic rocks within the Zamora Batholith (Leary et. al., 2016). In May 2017 Lundin Gold announced that the construction of the mine facilities had started and that the results of a new feasibility study indicated that the first gold pour would now occur at the end of 2019, earlier than previously expected, and that the mine would produce over 300,000 ounces of gold and 350,000 ounces of silver per year for 15 years (Lundin Gold Inc., 2017).

Thereafter, INV Metal’s medium-scale, underground gold mine at Loma Larga (formerly Quimsacocha) southwest of Cuenca (Figure 2) could start production at the end of 2020 (INV Metals Inc., 2017). The mine is designed to produce at an annual rate of 150,000 ounces of gold, 850,000 ounces of silver and 2,500 tonnes of copper, all in concentrates, for 11 years from a high-sulphidation, epithermal deposit (Cox et al., 2016).

Meanwhile, evaluation of Salazar Resource’s El Domo volcanic-hosted, massive sulphide deposit located in submarine volcanic rocks of the Macuchi Island Arc unit in the west of the country (Figure 2) is well advanced (Salazar Resources Ltd., 2017). According to Calvo and Johnstone (2015) the first nine years of mining may be from an openpit with an annual output of 70,000 tonnes of concentrates containing about 65,000 ounces of gold, 1.3 million ounces of silver, 14,000 tonnes of copper, 21,000 tonnes of zinc and 3,000 tonnes of lead. A further five years of production may come from an underground mine with an annual output of about 9,000 ounces of gold, 90,000 ounces of silver and 9,000 tonnes of copper.

Combining the above planned production figures with the historic background output of about 200,000 ounces of gold per year (and assuming a 67% expansion of production at Mirador, to 50,000 tonnes per day, in mid-2020 and the start up of the El Domo mine in 2022) generates the production profile shown in Figure 1. This diagram indicates that, if all the currently planned operations come into production as planned, Ecuador could reach a total output capacity of about 120,000 tonne/year of copper, 800,000 oz/year of gold plus 3,000,000 oz/year of silver and 20,000 tonne/year of zinc by the mid-2020s. After 2030 production will start to decline, and by 2036 all the mines listed in Table 1 should, theoretically, be worked out. However, many of these mines will probably find extra ore to keep operations going long after the dates implied by the present planning.

Potential for More New Mines

Sustaining the levels of metal production seen in the second half of the 2020s will eventually require the opening of new mines. There are no base-metal rich, volcanic-hosted massive sulphide deposits in Table 2, and there is only one, relatively small, epithermal gold deposit (Jerusalem). However, Table 2 does contain five porphyry copper deposits with a minimum gross metal content of 1 million tonnes of copper and three porphyry gold deposits with a minimum gross metal content of 3 million ounces of gold.

As far as copper is concerned, bringing any one of these porphyry copper deposits into production, either as an openpit or a bulk underground operation, at 50,000 tonnes per day, or more, and at a grade of 0.6% copper, or better, would replace the production from the Mirador mine. The proximity of TNFNG/CRCC’s Mirador Norte, San Carlos and Panantza deposits to its Mirador mine suggests that this Chinese consortium may be producing copper from southeastern Ecuador for perhaps decades after the Mirador mine itself is worked out.   In addition, the high grade and large size, of the Llurimagua deposit in the northwest of the country suggest that this deposit may eventually host a large-scale, long-life copper mine.

As far as gold is concerned, the Santa Barbara, Gaby and Cangrejos porphyry deposits may each have enough volume to support a 50,000 tonnes per day openpit or bulk underground mining operation. Nevertheless, the low gold grades may require a somewhat higher gold price than at present for a conventional mine and mill operation to be economic. However, both Gaby and Cangrejos have the advantage of being on the western side the Andes and within easy reach of the port at Machala (Figure 2).

Of particular, current interest is the Alpala copper-gold porphyry deposit, one of the multiple targets within the Cascabel project, in the northwest of Ecuador (Figure 2). No resource estimate has yet been released. However, current drilling is focused on a mineralized trend about 2,300 metres long by 700 metres wide with an implied vertical extent of 1,700 metres, and results already include seven intersections with drillhole lengths of 950–1340 metres at grades of 0.4–0.8 % copper and 0.4–0.9 g/t gold (Solgold plc, 2017a,b). Provided the deposit meets current expectations, a 50,000 tonne/day mine, or bigger, based on this single project would make a major contribution to ensuring Ecuador’s continued production of both gold and copper beyond 2030. Furthermore, the high grade zone starts at a depth of about 500 m below the surface. Consequently, any eventual mine may be a bulk underground operation comparable to Cadia East in Australia, where Newcrest, who have just invested an additional USD 40 million into the exploration at Alpala (Lazenby, 2017), are currently producing over 20 million tonnes of ore per year from a purely underground operation (Newcrest Mining Limited, 2016).

The continuation after 2030 of the production of zinc, and to a certain extent of silver, at the levels foreseen in Figure 1 for the second half of the 2020s will require the discovery of more volcanic-hosted massive sulphide deposits rich in these two metals within the Macuchi Island Arc unit (Figure 2). Currently, Salazar Resources is continuing to explore the Curipamba project around the El Domo deposit (Salazar Resources Ltd., 2017), and Toachi Mining is exploring around the old La Plata mine (Toachi Mining Inc., 2017)

Threats

The government now recognizes mining “as a key strategic sector for the country” (Ministry of Mining, 2017). However, there is still strong opposition within parts of the Ecuadorian population, and especially within the indigenous population, to the entire concept of industrial-scale mining. This opposition is based on both environmental and cultural grounds, and it is especially strong around the Panantza/San Carlos deposits (Valencia, 2016) and the Llurimagua deposit (Jamasmie, 2013). Finding a satisfactory and enduring solution to this resistance will be a key element in the development of any mines based on these deposits.

In addition to man-made challenges, Ecuador’s tropical location astride the Andes on the west coast of South America make it prone to natural disasters including earthquakes, volcanic eruptions, flooding, and large landslides. Although such extreme natural events can disrupt and delay mining projects, they are unlikely to stop them in the long term.

Conclusions

Provided that the government continues to support the mining sector, Ecuador is currently on track to achieve an annual output capacity during the second half of the 2020s of about 120,000 tonnes of copper and 800,000 ounces of gold plus 3,000,000 ounces of silver and 20,000 tonnes of zinc, mostly in the form of concentrates, from mines currently coming into production. Furthermore, there seem to be enough porphyry copper deposits under evaluation to provide the additional mines that will be needed to sustain, and perhaps increase, this level of copper production well into the future. However, sustaining the gold output with production from new mines based on the porphyry gold deposits already identified will probably need an increase in the gold price, and maintaining the zinc output, and to some extent the silver output, will require the discovery of more volcanic-hosted massive sulphide deposits.

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