The Nanjing Belt ~ An Ancient Aluminium "OoPArt"?

The Nanjing Belt
The chronological dating of our technological development and capabilities within antiquity, are often correlated and judged upon the developments within heat management of metal refinery.
For example, one of our strongest arguments against the modern day, attested view that ancient Egyptians were the builders of the sphinx, the pyramids, the tombs etc... Is partly based upon their lack of ability in heating a furnace to a sufficient enough temperatures, to create the hardened metal tools needed to penetrate and carve such hard stones.
The Nanjing Belt is an extremely rare find that has, unsurprisingly vanished from public view, preventing any further analysis, although the existence of these artefacts was officially noted in several places, and was indeed analysed by several specialists.
What is amazing regarding the Nanjing Belt is its age, but most importantly, what it is made of...
In 1952 two tombs were found within Yixing City in China, one of the tombs also had a clear date inscribed upon its inside, it stated that they were buried on the 20th of September of the seventh year of Yuankang, the late general of Zhou.
17 hundred years ago.
When the belt was initially retrieved, it was sent for analysis at the chemistry department of Nanjing university, the results were astonishing, 10% copper, 5% Manganese, and the remaining was 85% pure aluminium...
However the development of Aluminium is a very modern achievement, requiring extreme heats to smelt, heats that we believe were impossible to manage at the time...
Alumina is dissolved in molten cryolite at 1,000 degrees C, with the melting point of pure alumina being 2,054 degrees C.
So the question persists, just how could such an artefact exist?
A question once taken up in the west by three scholars – Butler, Glidewell and Pritchard – at St Andrew’s University. Titled, ‘Aluminium Objects from a Jin Dynasty Tomb – Can They Be Authentic?’ Interdisciplinary Science Reviews,1986, volumes 88-94.
The abstract sums up their work, quote:
Pieces of aluminium, supposedly parts of a set of belt ornaments, were found in a Jin dynasty tomb, during excavations in the 1950s. The authenticity of these finds was questioned at the time in view of the technology required to isolate aluminium from its ore. Examination of the thermodynamic requirement for this process, demonstrates unequivocally, that the temperature required for this process is greatly in excess of that possible with Jin dynasty technology, and so the finds cannot be authentic.
Unfortunately, again, we find ourselves in familiar waters… So called scholars, three in fact, with a conclusion, based solely upon historical assumptions.
Unfortunately, the artefact was seemingly too controversial for some, and it has vanished, sadly quite possibly forever.