Avino Silver & Gold Mines Ltd. (Avino) has announced its 4Q18 and FY18 production results from its Avino property near Durango (Mexico).
During 2018, material mined from the Avino mine (Elena Tolosa (ET) area was processed using Mill Circuit 3, as well as Mill Circuit 2 through mid-July. In the latter portion of July, Mill Circuit 2 transitioned to processing Avino historic above ground (AHAG) Stockpiles, and on 24 September, Mill Circuit 2 began processing mined material from the newly-developed San Luis area of the Avino mine. Mill Circuit 4 was commissioned on the AHAG Stockpiles and continued to process this material through all of 2018. Through 2018, Mill Circuit 1 continued to process San Gonzalo ore.
Avino mine production highlights
Mill throughput was down 7% on a quarterly basis due to switching Mill Circuit 2 to San Luis material from AHAG Stockpiles. Copper and gold grades increased 19% and 45%, respectively, compared to 4Q17, with only a slight 7% decrease in silver grade.When examined on a yearly basis, overall mill throughput and calculated silver ounces are lower, as a result of Mill Circuit 2 processing historic stockpile material during 3Q18, as we have mentioned above and in previous press releases. The lower tonnage processed combined with the variations in feed grades resulted in an increase in copper production by 4% and silver and gold production decreased by 24% and 12%, respectively, for the year compared to 2017.
The copper feed grade increased by 14% while the silver and gold grades decreased by 17% and 5%, respectively. The change in grades was mainly due to the areas being mined at the ET and San Luis areas.
Despite the lower throughput from the Avino mine, the consolidated production numbers show an increase in overall production as we varied our feed mix to each mill circuit throughout the year to maximise profitability.
Finally, underground development was also up 31% on a yearly basis as we continue to develop both the ET and San Luis underground areas at the Avino mine.
San Gonzalo production highlights
At San Gonzalo, the mine is approaching its end of life and the grades, recoveries and production have started to tail off. This is in line with our internal expectations.
During 4Q18, silver and gold feed grades declined by 41% and 35%, respectively, compared to the fourth quarter, 2017, along with a decrease in both silver recovery, and to a much lesser extent gold recovery.
Combined with a 5% decrease in mill feed tonnes, there was a resulting 47% decrease in silver equivalent ounces produced.
On an annual basis the silver and gold feed grades declined by 17% and 22%, respectively, compared to year end 2017. This combined together with a slight decrease in both silver and gold recovery lead to San Gonzalo producing 25% fewer ounces on a year over year comparison basis.
These lost ounces were more than offset through the addition of Mill Circuit 4 and the processing of the AHAG Stockpiles as discussed below.
Historic above ground stockpiles production highlights
In 4Q18, Mill Circuit 4 processed 69 033 t of the AHAG Stockpiles, producing 138 449 silver equivalent ounces. As per the company’s 18 July press release, Mill Circuit 4 started processing material in May 2018; therefore, the 2018 figures reflect that start-up date, including the initial commissioning phases, where the mill was not running at its 1000 tpd capacity. In keeping with the company cost reduction initiatives, which were announced in the third quarter 2018, Mill Circuit 2 also processed the AHAG Stockpiles material to allow reduced underground work at the ET area of the Avino mine. A total of 202 830 t of AHAG Stockpiles was processed through the mill circuits, which added a total of 380 766 silver equivalent ounces to our overall consolidated silver equivalent production.
Avino mine expansion (San Luis area)
The San Luis area of the Avino Mine is accessed through a separate portal located approximately 2 km from the main entrance of the Avino Mine (Elena Tolosa area). Current resources at San Luis were included in the most recent resource estimate on the Avino property, which can be found in Avino's news release dated February 21, 2018 on Avino's website and under the company's profile on the SEDAR system. The news release was also filed with the SEC on Form 6-K.
San Luis material is currently being processed in Mill Circuit 2 until sufficient underground development has been done to transition to processing this material to the larger Mill Circuit 4.
During 4Q18, the company did not continue its testing programme for recovery of precious metals and zinc from the San Gonzalo tailings, due to lower grades. The company will evaluate the zinc circuit on a quarterly basis and may resume its testing programme in the future.
Read the article online at: https://www.globalminingreview.com/exploration-development/21012019/avino-shares-4q18-and-fy18-production-results/