attention geologists

This board has the blessing of being frequented by some astute geologists. Please critique the following notes regarding arkose and beneficiation. The notes were compiled to aid understanding. Thanks in advance for any contributions.

ARKOSE

1 The rock formation at Browns Range is Arkose (pronounced arkous). Arkose is a detrial formed from particles of pre-existing rock through weathering and erosion. To be defined it must contain at least 25% Feldspar. Usually it is up to 60% plus quartz, which as we know is a crystal. In simple terms Arkose is a relatively soft sandstone rock generally surrounded by its own sand. Uluru is an Arkose rock.

2 The Feldspar group of minerals are a family of silicates of over 20 members, which occur in igneous rocks. Feldspars crystallize from magma (molten rock in the earth's crust) into the sandstone as veins and are readily identified in the photographs shown in NTU literature (clusters and light brown in colour). See photograph on Wikipedia. Xenotime is part of the Feldspar group.

3 Xenotime is a rare phosphate mineral whose major component is yttrium orthophosphate (ypo4). It forms into a solid solution and may contain traces of arsenic as well as silicon dioxide and calcium in its final composition.

4 The expressive secondary components of Xenotime are the heavy rare earths dysprosium, erbium, terbium and yterbium and may sometimes contain metal elements like thorium and uranium (all replacing yitrium). Occasionally gemstones are also cut from the finer xenotime crystals. NTU continually provide %-components of these HREE in their reports to shareholders.

FLOTATION BENEFICIATION TECHNIQUE

First of all think coal mining. The coal is removed from the mine and crushed. The dirt is separated from the coal using a water wash medium. Then through a series of processes using water chemicals carbolic acid an alkali metal or ammonium salt thereof the coal is cleaned. Flotation beneficiation has resulted in a better product freer of impurities and thus more marketable.

Northern Metals believe using a related process they can remove the xenotime from the arkose at the mining site and thus provide a concentrated material suitable for refinement - a compound of heavy rare earths that can be easily transported

For some ideas on how such a process would work, google the word HYDROCLONE and look at some of the engineered hydroclone systems from chemindustrial situations. The process and equipment is much more advanced to that used in the early days of coal cleansing.