drilling summary

I'm going to preface this by saying that I am very new to AVB so I haven't gone right back in time and I gather it has a fairly long history - I've only been following it (and a shareholder) for a couple of weeks - before that I had never heard of it (just because I hadn't heard of it doesn't mean that there is anything wrong with it though, I've just got a lot more spare time available at the moment than I normally have so I'm actually getting some research done for a change). Also I'm only summarising stage 1 drilling at AN.

Before I get into the nitty-gritty of the drilling I will explain for those new to mining that planning how to get the dirt out of the ground isn't just down to one guru who looks at some figures and a map and then goes and paints some lines on the ground and says "dig here!". There is a heck of a lot more to it than that, and it involves a group of people with different qualifications and areas of expertise - geotechnical engineers, mining engineers, geologists, surveyors, drill & blast specialists, metallurgists etc etc.

At the moment they have several different types of drilling going on and planned.

The first of these is resource drilling, which is providing us with all the pretty pictures of core at the moment. This is being done with a diamond drill rig. Resource drilling is very important for the company in several ways at the moment -
- it proves to the banks that are going to lend them money that they really do have what they have said that they have, and it provides a lot more detail and confidence in that regard through the all-important JORC
- it proves to shareholders likewise, which will help if they have to do a cap. raising in the future
- it helps with mine planning - showing where the economically mineable ore is - and isn't - which helps with designing a pit.
- it also gives some info (but not enough) to people like metallurgists who are involved in the processing of ore and getting the maximum recovery of minerals from it - contrary to what some people think you don't just feed all the ore into the crusher and get 100% of the minerals out the other end of the process plant.

The current drilling is spaced at 25 metre intervals, which is quite reasonable to get a good understanding of an ore body of this type. Geologists (aka Rocklickers) will be watching the core coming up very closely due to the shallow depth of the ore body - they don't want to waste the drilling budget by drilling wasted metres beyond the bottom of the ore body.

From what I have seen this ore body looks fairly nice to work with - shallow, and not riddled with waste patches through the ore body (when you get an ore body like that it is a nightmare for everyone).

They will be getting some good information out of this to help build up a picture and plan not just the pit design, but also the mining. A lot of people think that you just send the ore to the crusher and drop it in, but the reality is that higher grade ore is blended with lower grade ore to try to keep the grade going through the plant as consistent as possible - you get better recovery this way, use less chemicals and it makes the life of everyone running the processing plant much easier. If they get an area of the ore body with a high clay content they will try to blend that with ore from other areas of the pit that has less or no clay to reduce the clay % going through the plant at any one time as clay can play havoc with some processes.

It looks like the current reserve drill out is a 23 hole program, 10 holes completed, 3 in progress and 10 more to be done. That could change though depending on what they find along the way. This is a fairly sane program so they should be able to keep up with the information flow (visual of core as well as assay results) as it comes and adjust accordingly. I worked on a project that had 110 drill rigs running 24/7 and there was just too much information coming in too fast, important information was getting missed, misplaced, or not making its way up the chain, and it was total and utter chaos.

Other pit drilling to follow the current reserve drill out is geotechnical drilling which is done to assess the stability of the rock where they want the pit walls to be - in simple language this determines how steep they can safely make the pit walls - the steeper they can safely make them the less waste they have to mine which equals dollars and time saved.

They are also planning two holes for additional metallurgical information. There hasn't been any information given as to what they hope to gain from these two holes, and I would only be guessing - possibly something to do with process plant optimisation.

Drilling being undertaken outside the planned pit is doing a few different things -
- ensuring that where they plan to put the tailings dam has a nice hard base - testing for that will be part of the requirements for the full mining licence I would expect - tailings dams can be disasters - both human and ecological if not done right or put in the wrong place.
- drilling to ensure that there isn't a mineable orebody underneath where they put the waste heap - I think I mentioned in a post yesterday about a site where I used to work putting 20 million tons of waste on top of ore - they had to move all 20 million tons to get at it.
- drilling to test the stability of the ground where they intend to put things like the process plant - if you haven't been on a process plant before I will let you know that some of them have a hell of a lot of vibration and rocking, and mills create a lot of energy - these sorts of things need to be mounted pretty solidly or else one day it will all come crashing down. This drilling will determine how deep the footings for the plant etc need to be.

Hopefully I haven't forgotten anything? Any questions fire away.