Ann: Change in substantial holding from HHL,HHL-BLK.AX, page-33

You are obviously researching diligently.

You say "Fact based" so I am surprised you still find the Biox process to be "fatally flawed" at Wiluna (or in your own words: There is also lots of sulphur and the plant can't process ore that contains to much sulphur without rusting apart. This means that the gold is going to stay in the ground ).

I can't remember if you have given detailed and well referenced reasons for your views. If you have could you please give links to them?

If not could you provide a detailed explanation with appropriate material that demonstrates why the processes is so flawed?

My view is that BIOX is a well established process for certain types of HIGH SULPHIDE CONCENTRATES (i.e. NOT ore) including those produced from refractory ores found at depth at Wiluna and Bulletin in particular.

This recent post from OzzyJack gives the basic history of Gencor's Biox system and its evolution over some 40 years. If the process is "no good" and rusts out equipment then it is a mystery to me as to why so many companies continue to use it successfully(??) after this period of time.

That Apex didn't have any success with the Biox process is well known but knowledgeable posters have said that they didn't use it correctly .....

Previous Wiluna operators did get it to work well as Whyme's post shows successful production from mixed ores, including sulphides, from 1994 to 2007.

The aspect of Whyme's post that you seem to ignore in your anti Biox argument is above the histogram as shown in this snip.



The high ratio (including 7 years at 100%) of Sulphide to Oxide across 1994-2007 shows that the BIOX system worked at Wiluna. How do you explain this? Please give a detailed referenced response as to why it was successful then and will fail now.

H you have mentioned variation of sulphide ores with depth so I tried to find some details of what, and where historical ore was sourced but couldn't find any details in a brief search.

From BLK's 2016 Diggers and Dealers presentation there are these images


I would imagine the gold coloured areas were a major source of historical refractory ores including the Biox years 1994-2007 and maybe APEX years. The Blue areas may be what BLK will attempt to mine in several years time according to the current mine plan. Corrections and expansions wanted on this - Thanks.

Hagetaka, if the 1994-2007 ore was sourced, in part or whole, from these workings and processed successfully why would BLK have problems and need a thousand years to get out 100Koz when past operators only needed a year?? Since 2007 the BIOX plant may have rusted/deteriorated but it could be refurbished and any new technology added at a reasonable? cost.

A few questions in here for you Hagetaka. I don't expect to change your mind but I would be interested in the details of why you hold views which are contrarian to the majority.

The answers are important because, as you say there is a lot of gold and ultimately it will be the successful exploitation of the sulphides that will turn BLK into a really great long term project as distinct from just a good one IMO.

Cheers
S