The following blurb from Albionprocess.com probably describes the sort of testing that Envirogold's tailings have undergone to estimate how viable the Albion process will be in treating them.
"Core Resources can discuss a program that would quickly evaluate any new ore/concentrate for applicability of the Albion Process technology and support the design and construction of process facilities.
Testwork would initially be carried out at hrltesting's Laboratories in Brisbane, Australia, and by arrangement at other facilities in later stages.
This testwork is usually conducted in three phases:
* Scouting testwork * Batch Development testwork * Continuous Pilot plant testing
Scouting testwork is designed to determine the "pass/fail" nature of the ore/concentrate in question. A single fine grind and leach test at a grind size of say P80 of 8 [microns] and high sulphur oxidation would be conducted. Sample requirements are of the order of 2 to 5kg of concentrate.
Batch Development testwork is designed to optimise the various unit operations, e.g. flotation, fine grinding, oxidative leaching and cyanidation (if precious metals are present). The aim of this stage is to provide sufficient information to conduct an initial pre-feasibility level cost estimate for the processing plant. Sample requirements are of the order of 5 to 20kg of concentrate.
Continuous pilot plant testing can be conducted at a range of scales depending on the quantity of sample available and the scale up requirements to gain the necessary levels of confidence for a bankable feasibility study. During the piloting phase, the chemistry, mass and heat balance modeling of the Albion Process under steady-state conditions is determined along with all engineering design data that is needed for plant design, capital and operating cost determination to feasibility study standards."
-------
The following history records that this sort of evaluation has indeed been carried out on the ores at Pueblo Viejo (The tailings of Las Lagunas were derived from open pit operations at the adjacent Pueblo Viejo gold-silver mine) in the Dominican Republic:
"History
The development of the Albion Process has parallelled the development of revolutionary new fine grinding mills (IsaMill) in the base metals and gold industries. The emergence of efficient low cost fine grinding machines has enabled leaching to be carried out under far less demanding conditions than previously required in pressure or bacterial leach plants.
MIM Holdings began developing the Albion Process technology in 1993, while looking at a treatment process for the high arsenic copper/gold resources at Nena/Freida River in Papua New Guinea.
Various small scale continuous pilot plant campaigns on this ore were conducted in 1994 and 1995 for Highlands Gold (which was later floated from MIM Holdings and is now Highlands Pacific).
A larger pilot plant (120kg zinc cathode/day) was constructed in 1997 to conduct testwork as part of a feasibility study on the zinc/gold resources of Pueblo Viejo in the Dominican Republic.
Extensive piloting was also conducted on lower grade chalcopyrite concentrates for Cyprus Amax in 1998, and for Mount Isa Mines in 2000.
Pre-feasibility and feasibility pilot testing was conducted on the zinc/lead bulk concentrates from McArthur River and Mount Isa in Australia between 2001 and 2005.
During this time the Albion Process has been successfully tested on over 70 different ores and concentrates.
Xstrata continues to actively develop the technology for its copper and zinc projects.
In parallel with these developments the IsaMill technology (which is the enabling technology for the Albion Process) has been further developed into an extremely robust, proven and now large scale ultrafine grinding technology, with 18 mills [more like 86 now - see IsaMill website] now in operation around the world. IsaMill technology now represents the largest installed capacity of any ultrafine grinding technology in the world."
------
The Albion process is also described on Envirogold's website. under the menu "The Technology."
EVG Price at posting:
8.5¢ Sentiment: LT Buy Disclosure: Held
