Clifton Star Resources (CVE:CFO) unveiled Monday what it called "excellent" metallurgical test results on gold flotation concentrate treatment from its Duparquet project in Quebec using two different processes.
Results were received from Goldfields of South Africa for BIOX process amenability, and from Albion Process Limited for the XSTRATA Albion process amenability.
The BIOX process, as an alternative to pressure oxidation, uses bacteria to catalyze the oxidation of pyrite and arsenopyrite prior to gold recovery by carbon-in-leach cyanidation.
The XSTRATA Albion process uses fine grinding and neutral oxidation of pyrite and arsenopyrite prior to gold recovery by carbon-in-leach cyanidation.
The overall gold recovery achieved in BIOX testing of concentrate from the Duparquet project ranged from 94.3 to 94.7 percent, while the overall gold recovery achieved from the same concentrate with the Albion process was 93.8 percent.
Clifton said these numbers compare "well" to the overall average of 93 percent gold recovery achieved by SGS Lakefield tests, announced in March.
In each case, gold was recovered by cyanidation in leach, after the BIOX, Albion or pressure oxidation pre-treatment.
"These results on BIOX and Albion testing confirm that the Duparquet resource is not difficult to treat from a metallurgical standpoint," said president and CEO of Clifton, Michel Bouchard.
"Two conventional processes (BIOX and Pressure Oxidation) and one emerging process (Albion) have all proven capable of achieving high gold recoveries from Duparquet concentrates.
"The choice between processes may now be considered based on relative economics."
The BIOX process was developed in South Africa and first applied at the Fairview mine. Currently, four sites around the world are using the process, including the Ashanti Goldfields plant in Ghana, which treates 960 tonnes per day of concentrate prior to cyanidation for gold recovery.
The Albion process was developed in Australia and has been applied in the zinc industry for leaching zinc concentrates. It has been licensed for gold applications in the Dominican Republic and Romania.
Earlier this month, Clifton Star said that metallurgical test results also showed that high gold recoveries from historical tailings at its Duparquet project in Quebec are possible.
These high recoveries were seen using a combination of conventional flotation, pressure oxidation and cyanidation, the company said.
The overall gold recovery from the tailings sample obtained from the historical Beattie tailings was 83.5 percent.
These metallurgical tests are part of a larger program that previously led to average gold recoveries of 93 percent from core samples of the different gold zones of the Duparquet project, as announced in March.
A preliminary economic assessment for the Duparquet project will follow the upcoming NI 43-101 resource assessment report from Innovexplo, now expected in May of 2012.
The new NI 43-101 compliant resource report for the entire project will move the Beattie and Donchester deposit estimates under the same criteria and allow for one data bank for the whole project.
The Beattie area of the Duparquet project is currently estimated to contain 1.72 million inferred gold ounces at a cut-off of 0.67 g/t gold, all in pit resources, as opposed to the current cut-off of 1.5 g/t gold used in the NI 43-101 report for Donchester.
Shares of the company advanced 0.7 percent Monday morning.