The recovery of gallium from the Bayer liquor solution was considered in the Western Australian alumina operations many moons ago. A geochemist may be able to provide more information but I suspect a lot of minor metals would be removed from the iron rich slurry by the caustic leaching process (cf. gallium).

Besides others have been working on this problem of recovering REE from Red Mud. But considering the enormous quantities of millions of tons to be handled and disposed of in the context of environmental protection the only logical solution seems to be making of bricks of an acceptable quality. A lot of work has also been done/attempted by many organizations abroad as well. Indian Govt. has stipulated that only Fly-Ash bricks have to be used for all government constructions within a radius of 100 kilometers of any coal based power generating station. A similar rule in case of any Bauxite processing plant generating Red Mud with an onus on the unit to offer the waste material in a suitable form for making bricks should be considered. This has been a major issue in this part of the country where I live. It is a cause of severe social unrest in the proposed bauxite mining areas in the Eastern Ghats.

I too saw on net many industries want to extract Gallium. Today USA is short of this metal. China is not able to export. India it is not economical. Can you send me brief of the process?

Recently I attended a seminar in Mumbai where this point was discussed. It was found that the quantum of waste and brick consumption do not match, Still problem will remain same. Alternative solutions given are---Use red mud to make cement. Huge requirements are not yet met.

3. Very soon India will be going for commercial production of the chlorination process.

Orbite alumina’s revolutionary technology have solution for Bauxite the proprietary process developed by Orbite extracts alumina through hydrochloric acid leaching. The traditional Bayer process currently used by the aluminum industry dissolves bauxite in caustic soda to extract alumina. The Orbite process does not generate red mud residue. More importantly, the Orbite process can be used to treat existing red mud, extracting the residual alumina and other valuable metals in it, while completely eliminating the toxic elements. This technology presents an attractive opportunity for companies operating alumina extraction plants, and for governments of regions with red mud deposits as a solution to eliminate the environmentally damaging material. In addition Orbite process can extract and process other elements in the bauxite, thereby capturing silica, hematite, gallium, scandium, magnesium, and rare earth elements for further commercialisation. Please check white papers available on their website for details.

A relatively expensive reagent for leaching - although a 'white paper' claims there a 'few acid losses' as well as regeneration so the solution can be recycled to lower acid costs.

Chloride bearing systems under high temperatures and pressures are tough on materials - usually some exotic and expensive materials required. The 'white papers' does not discuss the engineering aspects, which is a critical aspect.

The process seems to bear some similarities to the sulphuric acid leaching of nickel laterites (HPAL) - in that most of the high acid consumption is due to the dissolution of the iron, which is then precipitated as ferric hydroxide. In Orbite's case, they propose that the iron product is sold.

So far a pilot plant has been apparently operated, however no details of the technical and engineering assessments were available.

A work in progress, with a demonstration plant required. All sorts of problems, both technical and engineering, arise with each scale up in size as well as with continuity i.e. recycle streams, unexpected reactions, etc.

Overall an interesting approach - I like the idea of recovering the iron (although a bit of hassle - the typical liquid/solid separation issues of hydrometallurgy), the potential for recovery of other elements (SX and precipitation operations) and if they really can minimise the acid consumption, then the potentially high capex may well be offset.

My earlier enquiry addressed to Orbite did not get any response. Would you have any further details of the pilot plant trials? This is of topical interest in my part of the country - Eastern Ghats area - where there is a problem of Red Mud already generated and to be generated by proposed Alumina Plants.

Chloride process for your red mud may be costly. You can go for producing cement form red mud.

You can contact Nagpur-aluminium dept., doing such research.