Geology & GeoMetallurgy

Geology & GeoMetallurgy

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Started by Hauptsturm
Busy reading an interesting report for a Narrow Vein Greenstone belt mine which uses 'sludge holes' for grade control and sampling purposes. To be honest, I have never encountered sludge holes before. I gather these are pneumatically drilled holes a...
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Last commented on by PJ
Did you successfully figure out a way to catch jumbo cuttings prior to them landing on the sill?
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Started by Maya Rothman
In Gold Exploration, what is best Geophysical methodology or technique to explore primary gold, and establish quartz veins in Mica Schist bedrock.  Our exploration license is producing Gold Nuggets at 30 cm depth using metal detector. I know I ...
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Last commented on by rajesh
sir can u give some more information about velligallu schist belt exploration technics?
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Started by Victor Bergman
Can we define the skills and field of study of a "Geometallurgist"? Are we able to define a specific undergraduate program in Geometallurgy?I would like to hear what is your ideas on this topic. How prepared should an engineer or geologist be to cov...
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Last commented on by Emerald coordinator
I'm contacting you from the University of Liège (Belgium) to let you know that we are currently coordinating together with the University of Lorraine (France), Lulea University of Technology (Sweden)...
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Started by Tarun Karakoti
How to sample a small stockpile of coking coal?
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Last replied to by Obergruppenfuhrer
The solution we have a client who did cooking coal in Germany with great success. Obviously the handling of sample and barrel is a bit challenging but can be won.
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Started by
Has anybody been convinced of the appropriateness of a continuous wet face-sampling RC program? Assuming the wet sample with copious water will flush the system clean and allow for representative sampling. Particularly in regards to an environment w...
Last replied to by Oberfuhrer
Depending on site conditions and targets, sonic drilling might be the clever answer to RC sampling problems. RC is all about cheap meterage. In some cases this may pay, but usually it is safer to get ...
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Started by Raje Singh
I am working on a Reconciliation uncertainty associated with mine production and I want to know where technical and geological activities come into play.
Last replied to by
The general opinion is that long term reconciliation is more reliable than short term reconciliation, but compensating errors can hide a multitude of sins too. One needs to be careful of reacting to s...
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Started by
When taking a 'A' and 'B' sample from a cone splitter on an RC rig and comparing those weights, what differences in weights between the two samples would you start to think there was a problem. Is this also commodity dependant e.g. gold vs. iron ore.
Last replied to by Jean Rasczak
For one specific programme, we made an RDP plot ranking difference in weights between duplicates and setting them out against variance in gold grade to see if the variance would significantly increase...
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Started by
Problem - Mine grade control is reconciled back to the mill at the end of month with a single factor, effectively on a pro-rata basis. One of the ore sources commonly returns assays up to 1000g/t. Current procedure is to cut these grades to 100g/t ba...
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Cyclone overflows are also notoriously difficult to get a representative sample of. They contain the lowest fraction of solids (often 5-10%), so an enormous sample needs to be taken so that you can be...
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Started by Sudhirkumar
Which type of sampling method should we used in nummulitic limestone deposit
Last replied to by Zander Barcalow
I'm not sure what use you have for the limestone, but I have looked after a drilling program at a cement operation where we were drilling RC. That wasn't a nummalitic limestone and as per what earlier...
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Started by Oberstorm
Which are the steps for the Proportionate Stratified Random Sampling Technique? In which step we determine the size of the sample?
Last replied to by Gruppen
First you should identify the strata, which you assume or know to be homogeneous. How you proceed then depends what is the purpose of your sampling and how much apriority information you have. If your...
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Started by Maya Rothman
Is that correct during taking the duplicate samples (field duplicate, coarse duplicate and pulp duplicate) for one reference samples, let's say the reference sample is A, then A become A' for field duplicate, A" for coarse duplicate, A'" for Pulp dup...
Last replied to by Marshal Meru
In my experience the terminology used for duplicates in varied across the world and often confusing. My suggestion is that in agreement with your team clearly define (in writing) the meaning and metho...
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Started by Sandeep Bisht
Specific gravity determination method for Au-bearing sands/tailings of BIF origin, what is considered statistically significant sampling density by best practice, given a +2 million ton resource? What is the rule of thumb regarding backward computati...
Last replied to by Sandeep Bisht
Was also faced with the challenge of elevated BD numbers owing to the high Magnetite content of the BIF derived sands quite a monster when it comes to tonnage and mineral accounting reconciliations if...
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Started by Paul Morrow
In applying real-time on-line analysis techniques such as the Geoscan for Minerals - getting back to basics when deciding sample requirements is key to having accurate calibration data for the on-line analyser.Speaking generally, and even across comm...
Last replied to by Paul Morrow
Thanks you've provided a nice example in DrSans' Variographic Experiment at Phosphate Hill. In our experience, the true variability of the material is not understood clearly, and consequently the samp...
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Started by Subhash-Kumar-Roy
Is it correct to use two types sampling method in core preparation (half core and coning/quartering)?
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Last replied to by Unterstarm
Cone and quartering is applicable when you have a relatively large amount or coarsely (>30-50 mm) crushed of ore, good homogeneity of mineral of interest in rock, relatively high grade and low impo...
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Started by Victor Bergman
I don’t have much experience with sampling the soft stuff. We have a supergene enriched, probably erratically distributed gold deposit sitting on top of a "typical" shear-hosted deposit where the fresh rocks haven’t been touched. Tonnes of artisa...
Last replied to by Hauptsturm
In a similar situation, we performed close order hand auger sampling with 'bit and bale' type augers. With extensions and lots of manpower, we were able to reliably collect samples from as much as 10 ...
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Started by Gruppen
How to specify in PHREEQC that an element concentration is controlled by a mineral E.g. - Instead of specifying Pb concentration, specify that Pb is controlled by Hydrocerussite)
Last replied to by Victor Bergman
If you use the EQUILIBRIUM_PHASES block, and you equilibrate your solution with a solid, in this case hydrocerussite, without specifying what you want to modify to reach saturation with this mineral, ...
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Started by
Partly aimed at encouraging private space commercialization and maybe space mining, the US has passed a new space act.http://www.miningweekly.com/article/us-space-act-unanimously-passes-senate-vote-2015-11-11 http://qz.com/547119/congress-has-passe...
Last replied to by Paul Morrow
Panama, BVI, Seychelles. Or perhaps Kiribati could register all those space companies and use the proceeds to buy land in places a long way above sea level.
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Started by
Does anyone know of a technology that can successfully mine buried consolidated gold-bearing paleochannel? This would not include equipment suited for coal or tunnel boring machines.Also, does anyone know how to estimate the cost per foot of movable ...
Last replied to by
1yPlease tell us about your roadheader success and the specific ground conditions. I would also look at open pit economics.There is no 'economic' technology fix for modern drifting. I have visited UG ...
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Started by
It has been noted that most Geologists I have talked to have a preference for one meter of core being stored in each row of a core tray. Very few core trays manufactured have this capacity so why do we not manufacture core trays 700 or 800mm long...
Last replied to by
Stamped metal trays would be good for most geologist's applications and could be reusable if necessary. However in northern climates, freezing weather is a problem and metal trays would just be too co...
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Started by
I've been looking into the options for rotary splitters for RCP sampling and rmy bit of net searching turned up three on the market at the moment that look to be correct in terms of sampling theory. These are the Progradex ( see http://www.progradex....
Last replied to by
It's a rapidly spinning stream that sprays outwards to cylinder than the stream falls through sampling chutes. This overcomes the problem with getting many increments from the rotating stream and ensu...
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Started by Maya Rothman
Here is a problem of Poor Field Duplicate precision I first encountered when I was a young geologist working in a nuggety gold deposit, and now have recently encountered it again in a copper deposit. I would like to know if anyone has a suitable so...
Last replied to by
You have a problem and I assume that there is no bias between the field duplicates that suggests other than nuggets sampling? If not, then I think the suggestion of longer composites is the best first...
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Started by
Am looking for commentary on http://www.minassist.com.au/blog/geometallurgy-a-geologists-approach/Coming from the point of view of a geometallurgist with a metallurgical background, there is still some way to go in terms of fusing the disciplines an...
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The critical importance of Geometallurgy was presented at the Society of Economic Geologists conference in Tasmania September 27-30th 2015, which I attended. Geometallurgy and understanding mineralogy...
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Started by
Variability risk is conceptually accepted yet in my experience it is factually more often than not ignored. This renders it a major cause of metallurgical failures. Processing plants operate within a certain set of parameters tailored to the specific...
Last replied to by Marshal Meru
We have faced this issue many times as grinding media suppliers - but very rarely suggest equipment changes. Feed variations are the usual culprit with F80 and WI changes from the original plan. In al...
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Started by
Good or Lucky OR Lucky and Good. The geologist Jame David Lowell has a record and a career of which anyone would be proud. However many people who know him, including many of his admirers allude to a certain talent for garnering credit and a tende...
Last replied to by Victor Bergman
It was in fact hole 5, 6 & 7 of a 7 hole program. Hole 7 was the best, they patted themselves on the back for a good hole (5 & ^ were pants) and eight years later hole 97 was drilled outside the pit o...
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Started by
Let's talk about drilling geometry optimization, mineralization intersection geometry and structural vectoring as important drivers to mineral target development. Adding an orientation vector to the sample location is a very useful thing, assuming ...
Last replied to by
Indeed, XYZGV is a strong predictor of ore continuity and shape, I have many cases in which it was applied with success. Therefore, I have no doubt that this is the path to follow in exploration of mi...
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Started by Maya Rothman
I am working on lode copper deposit associated with thrust faults hosted in volcanic clastic rock. Copper occur in wavy Qtz-Py-Chalcocite vein and fracture fills. My question is about the copper minerals we have being chalcocite and covelite from s...
Last replied to by Maya Rothman
I meant the deeper silica-chlorite altered rock zone with quartz-chalcopyrite is the primary, but on the top of that is argilic altered with same vein but the chalcopyrite already enriched and become ...
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Started by
What the best geophysical survey method for exploring and discovering a porphyry copper deposit.After doing an extensive literature survey at the best University library I find these exploration methods:  The radiometric survey its important to...
Last replied to by Maya Rothman
I think you hit on the problem - remote sensing generally lands in the geography department at many universities and is often inter-tangled with GIS. And for classic 4 band imagery (B,G,R,IR) that is ...
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Started by Bob Mathias
I'm working on sulfides from a VMS deposits that were deformed at amphibolite grade, so pyrite seemed to have deformed by plastic deformation, but what is unusual it seems to form pressure shadows around euhedral sphalerite. I was expecting sphalerit...
Last replied to by
One of the remarkable features of these deposits is the presence of huge pristine twinned (90 degree) Staurolite crystals. That speaks of high pressure at the peak of metamorphism and no significant d...
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Started by
This article on the Genesis of Au-Ag-Mo porphyry-epithermal deposits has me a little unclear from the abstract but are they suggesting that part (or all) of the fluid in a porphyry system is vapor  or that the fluid behaves like a vapour? If the ...
Last replied to by
Very interesting summary about "refining" processes of the system Cu-Mo-Au in the porphyry structures. I could not read the article (than hard).Although the authors are based on experimental dat...
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Started by Bob Mathias
With technology today many companies offer Free Geology Software and freeware alternatives to specialized software packages. In this discussion I would like to ask what sort of free or low cost software alternatives are being used in the mineral expl...
Last replied to by Victor Bergman
GRASS is included in my QGIS package, what does it do that QGIS doesn't.
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Started by
Anyone with experience as to what is a reasonable expectation with regards to sample weights of RC samples collected from a cone splitter on the rig. RC sample weights - what is a reasonable spread?The current population has a mean of 2kg and a Std...
Last replied to by
I have been in the field and just re-read your post and other comments, and think that most of us who initially commented missed the point.It is clear that there is a systemic sampling bias, as indica...
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Started by Victor Bergman
I am looking for an app that works as GIS software , in which I can plot geochemical data set, drill collars , raster and vector maps etc. and would like to use these with GPS data at field.
Last replied to by
Don't know about the tablet version,but the desktop is good only if you have time to write scripts.Customer service here was nightmare. Also try http://logmate.com.au/
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Started by Bob Mathias
Remember the days a geologist would go out for cumbersome field mapping? An exciting topics for any exploration and/or structural geologist working as an academic or industry professional. Are Geology Apps and Compass for iPhone and "smart phones" ma...
Last replied to by
I’m always keen to give new technologies a go and see how they stack up against traditional methods. For me, a cellphone compass is great for collecting lots of measurements at a regional scale when...
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Started by Maya Rothman
I am preparing a Bre-X scandal summary and article about Bre-x fraud as am a geologist focusing on geological part with general idea how to avoid this fraud. Now I found only archive news or books from journalist who don’t pay attention on tech...
Last replied to by David
https://www.linkedin.com/groups/6589994/profile http://www.bdo.ca/en/Services/Advisory/Financial-Advisory/pages/Investigative-and-Forensic-Accounting.aspx
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Started by
My main area of interest is the development of a texture-based model for geostatistics. This is a radical alternative to the current variable by variable approaches. It is something I am aiming to pursue with one of my clients; but definitely not m...
Last replied to by
The issue has come up on the issue of definition of Geostatistics. I would suggest there are three candidates:branch of Statistics focusing on Geologybranch of statistics focusing on spatial or spati...

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