Jorge Diaz
Vice President of Operations
Sonoro Gold Corp
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Cerro Caliche is Sonora’s Next Promising Gold Operation

By Paloma Duran | Fri, 09/03/2021 - 16:59

Q: What makes Cerro Caliche a true gem for mining operations and a unique opportunity for investors?

A: I have worked on many successful projects and Cerro Caliche is as good as those and in some cases, even better. The exploration program is aimed to bring Cerro Caliche to production as soon as possible and we are pleased to say that we are achieving this goal. When we acquired the project, the existing mineralized structures had little exploration but we were able to see its potential. Sonoro´s exploration program tested these structures and after two years we have confirmed the high potential of the project, as of today we have sufficient resources to start a medium-sized operation. It has been a very rapid development and we look forward to continuing the expansion of the resource, especially in those areas that remain unexplored. With the current results of Sonoro´s exploration program the development of an initial operation phase is now a reality and other studies that have been under development during this period are as well providing positive results. This good news, among other things, means that relatively soon Sonoro will be able start its planned initial phase operation, to internally generate enough funds to continue the exploration program as well as the expansion of the project, at the same time maintaining a healthy financial structure.

 Q: How has the company progressed with its short-term development goals?

A: We have come a long way and we are very excited about the results so far. Today we are confident that we can start a first phase operation targeted at a 15,000 tpd of oxidized mineral level, which is very impressive for Sonoro´s two-year exploration period. Other investigation work results are supporting our positive assumptions on crucial issues such as metal recovery and positive percolation characteristics, which is a great combination since it has an important impact on the economics of the project. We are also confirming now that our mineral resource does not contain preg-robbing elements and is practically fully oxidized, which explains the good recoveries and a practically nil potential for acid drainage generation. All these elements have a positive impact. To be honest, the whole project looks great and encouraging.

Q: What characteristics make you believe that Cerro's Caliche’s heap leach mining operation (HLMO) could increase its conceptual capacity from 8,000 tons per day to 20,000?

A: When we did the first evaluation of the potential resources of the project, we thought we could have plus 2 M oz of gold in Sonoro´s property and we thought as well that we were looking at a low-grade deposit. Now, after two years of work we maintain our expectations in the total resource potential since the current results have confirmed the resources expectations in the explored area and we still have a further 65 percent of potentially mineralized zones remaining to be tested; all of them within Sonoro´s property. It is of worth to mention that as we have increased the density of exploration holes, we have been able to locate and delineate areas with higher gold content, which have allowed us to see a continuous increase of the average gold grade of the resource. We are fully aware that there are not many deposits of similar size and with under three years of work it feels very good that we have reached this level.

 Again, during this relatively short period Sonoro has proven our good expectations for Cerro Caliche. Not long ago the plans considered a production rate of 8,000 tpd for our initial operation phase, but the results today confirm a firm possibility of an initial 15,000 tpd phase, this means that we are rapidly approaching the potential for 20,000 tpd, which is very impressive.

Q: In which areas is Sonoro looking to improve at Cerro Caliche?

A: Yes, as a matter-of-fact, the potential for improvement opportunities is being considered all along this predevelopment stage. Cerro Caliche is a very large gold deposit with relatively low-grade material, and we are working to transform it into an economic resource by optimizing operating parameters. As it is known, one of the most important constituents in mining is process; here, an important research area being tested in the current metallurgical testing is related with heap percolation. Currently the met testing includes not only testing the amenability of the mineral to heap leaching cyanidation treatment, but current research also includes a thorough physical evaluation of the percolation performance in the columns where met testing is being conducted. According to the current results, there is positive evidence that confirms good expectations on the avoidance of an agglomeration stage, if confirmed it would bring important savings in the heap leaching process. 

Looking to the long run, the actual physical location of the mass of mineral, (mineralized structures located in the range of 100 meters above the leach pad area), opens an area of opportunity of improvement in the economics of the project in the medium future. This difference in elevation represents a potential source of power generation with the use of a conveyor belt to transport the mineral from the mine to the processing area. The use of a conveyor belt to transport the mineral downhill requires a braking system that could generate power. This opens up the possibility of an important improvement in operating costs and in the general economics of the project, lower cut-off grade, larger minable resource, etc.

Q: What factors make Cerro Caliche a smart operation?

A: Sonoro has a very efficient and multidisciplinary team that has not only sought to explore the deposit but has worked in turning it into an operation from day one. We have seized many opportunities in a very short time and at a very low financial cost. This is a smart operation because itis being fast, efficient and successful.

Q: How are you ensuring that Cerro Caliche starts production in early 2022, without delays or problems?

A: We have an aggressive operational plan for the end of 2021 and every step we have taken has paid off very well. We believe that we are on the right track because we have integrated a highly technical team that is not only expert in metallurgy and operations but also in social and environmental issues.

Sonora has a very good mining culture, and the communities understand the importance of the industry. We highly value our relationship with the communities, and we believe that our operation will be well received, especially because it will be an important generator of employment and wealth. The studies have shown very good environmentally related characteristics. It is a fact that our mineralization does not have the potential to generate acidic water or release toxic elements, and the design of the operations comply with best practices in the industry. For all these reasons it is expected that the attainment of environmental and other permits should proceed in a normal timeframe.

We are making good progress toward our goal of having our environmental documents ready early in 3Q21, today they are 98 percent complete.

Sonoro Gold Corp is a gold and silver mineral exploration company with a portfolio of exploration-stage properties in Sonora. The company has a highly experienced management mining team with a successful track record in discovery through resource development.

Paloma Duran Paloma Duran Journalist and Industry Analyst