Ann: ACQUISITION OF HIGH-GRADE ARAXA NIOBIUM PROJECT, page-148

Thanks @Paul88 great find, it should be compulsory reading for anyone interested in investing in this project.
I have not yet read it all, but have spent the last couple of hours with google translate, going through the last 3 documents on your list.

What seems to be pertinent is the amount of studies that need to be performed, including gathering just about every piece of information CBMM have on the large old tailings dam, called in the reports the CBMM B4 dam.
Then a multitude of specialist reports and investigations, based on the information from CBMM, plus a whole raft of new work.
Document 5311134 https://sei.anm.gov.br/sei/modulos/...aDEb654u77rx-SwNigFzEtWck4fDe6_nd6Vru16OQMNA2
even has a timetable for all these expert reports and investigations. pg 15
The timeframe is 24 months for all this work. The quotes below are as google translated it...

" REQUEST FOR DOCUMENTATION FROM THIRD PARTIES
2 HIRING A COMPANY SPECIALIZED IN GEOTECHNICS
3 EVALUATION OF THE DOCUMENTATION OBTAINED
4 FIELD INSPECTION
5 PREPARATION OF SPECIFICATIONS FOR COMPLEMENTARY SERVICES
6 CONTRACTING AND EXECUTING TOPOGRAPHIC SURVEY
7 CONTRACTING AND EXECUTING RESEARCH FIELD AND LABORATORY TESTS
8 HYDROLOGICAL STUDIES -HYDRAULIC
9 PREPARATION OF THE HYDROGEOLOGICAL MODEL FOR LOWERING THE MINE AND GROUNDWATER MONITORING PLAN
10 CARRYING OUT STABILITY ANALYSIS AND PREPARATION OF THE FINAL OPINION ON THE SAFETY CONDITIONS OF THE ENTERPRISE
11 STUDY FOR THE DISPOSAL OF STERIL
12 CONTRACTING THE REVIEW OF THE MINING PLAN

"REVIEW OF THE MINING PLAN Based on the investigations,
tests and stability analyzes carried out, the mining plan must
be reviewed by a specialized company in order to guarantee
the viability of the existing project and thus define possible changes
to adapt to the desired assumptions and imposed in the
geological-geotechnical studies of safety and stability of the
B4 Dam structure and pit slope."

At the conclusion of all the work and reports is where the review of the mining plan comes into the picture, which as the above quote states could lead to changes in pit parameters..

To me it tends to explain why Itafos hasn't done a feasibility study on this yet. A feasibility study has all the pit parameters included, to work out the mining costs and order of mining, yet they can't decide a final pit shape, size and design until all these other studies have been done first, and taken on board all the recommendations for safety and stability.

Will CBMM just willingly hand over all the information requested by another company? Do they have a choice? I have no idea how any of this works in Brazil, does anyone here?

IMHO, the reason why management didn't mention the tailings dam is in these studies. Lots of work needs to be carried out over time costing a lot of money for all these reports (including drilling observation pits etc), without any guarantee they can do the mining at all. The experts will determine this after all the research.

BTW, I was wrong about Itafos not doing any further work on this project. All they have on their website is the PEA, and in a heap of Corporate presentations the Araxa Project is qualified as "pending feasibility' with no further information about them doing any work..

Lastly, it still remain a mystery to me why management of SGQ didn't out, up front with anything about the B4 Dam, instead deliberately not mentioning it. Why not be up front, saying it's an issue that we intend to deal with by carrying out the investigations as per these technical papers, which is why we ere able to buy the project cheaply??

Thanks again Paul, looks like I have a whole lot more reading to do over the weekend of the rest of those documents.