Hudson Resources Inc. announced updated results for its alumina (aluminum oxide) development program on the calcium feldspar anorthosite from its White Mountain project in Greenland.
The objective of this phase of testwork is to produce smelter grade alumina (SGA) that meets both the chemical purity and physical specifications required by the aluminum industry.
Hudson, under the supervision of Hudson’s consulting metallurgist, John Goode, P. Eng., has now generated a number of alumina samples at SGS Lakefield’s laboratory facilities in Ontario.
The process involves three key stages, 1) leaching the anorthosite in hydrochloric acid ("HCl"); 2) sparging the leach solution with HCl gas to form aluminum chloride hexahydrate ("ACH") crystals; and 3) calcining the ACH at high temperature to remove the water and chlorine to regenerate the HCl for recycle and to produce the final SGA.
Critical to producing a marketable SGA product is ensuring that the physical properties match or exceed the required specifications from the aluminum industry, which requires two tonnes of alumina to produce one tonne of aluminum metal. Two key criteria are:
The percent of alpha phase alumina typically needs to average less than 7.5%, and;
The crystal surface area of the alumina particles (measured by a test with the acronym "BET"), needs to be between 60 and 80 square metres per gram.
Meeting these parameters is very challenging when using non-traditional (non-bauxite) ore as the feed material. Hudson has managed to meet or exceed these key parameters in part due to the unique nature of the White Mountain anorthosite and its high solubility.
Through extensive testwork, Hudson has now defined a preliminary flowsheet and operating parameters that produce an alumina product with a BET of 74 m2/g and a very low alpha content of 1.7%.
The BET and alpha-alumina tests were conducted at McGill University’s Department of Mining and Material Engineering. The determination of alpha alumina content used the Australian standard method (AS 2879.3 – 2010) for testing metallurgical alumina.
James Tuer, Hudson’s president, stated, "These results are a very significant step in the development of a flowsheet to produce smelter grade alumina from our anorthosite. Based on discussions with key industry players, we know that generating alumina using an HCl leaching method has proven difficult from a physical property perspective. Generally, it is relatively straightforward to meet the chemical purity specifications for SGA. However, meeting the physical parameters such as BET, low alpha alumina, and larger, stronger particles has remained elusive. We believe that our success to date has been due to the unique nature of the White Mountain anorthosite. As previously reported, we have utilized and improved upon existing, unpatented aluminum chloride production processes and we do not require any new technologies to produce a high quality product."
Metallurgical testwork is ongoing and an economic model is being developed to further evaluate the potential of White Mountain anorthosite as a new source of alumina. Currently almost all alumina is produced from bauxite using the Bayer process, which produces 2 tonnes of waste for every tonne of ore. Hudson believes the White Mountain project will have several saleable byproducts and will not produce significant tailings. Hudson has signed confidentiality agreements with several companies interested in the alumina project.
The White Mountain Anorthosite project is 100% owned by Hudson. The anorthosite has three potential high-value applications which are being investigated, as follows:
A new source of feedstock to the high end fiberglass (E-glass) industry;
A new source of alumina to supply aluminum smelters
A new source of filler material. Fillers are extensively used by the plastics, paints and paper industries
The company is rapidly advancing the E-Glass project with several Letters of Intent in place. The planned bulk sample test with a major fiberglass producer is commencing later this month. The environmental and social impact assessments and technical study are near completion and the plan is to submit them to the Greenland Government within the next few months as part of Hudson’s application for a mining permit.
Hudson remains well financed with approximately $2.5 million in working capital.