Glad to help. If you have any questions, just ask. Keith

Thank you.

Good sampling is both very important and not necessarily easy. :-)

This was a bit complicated for sure. There are two different things being tested at the same time. Mineral liberation is 'how fine do I need to grind the rock to break the gold particles free of the host rock'. I am confident that I recovered any of the larger gold particles and therefore any gold left in the coarser fraction is assumed to be still bound to rock particle. In general practice most gold would be liberated by a grind of minus 100 mesh and therefore any gold in that fraction is assumed to be free particles that were simply not recovered due to the inefficiency of the method. Both are important to know, but they are entirely different.

I used to skin dive and hold my breath when I move into the dust. Makes it hard to understand what I'm saying when it's on.

I believe I addressed that issue. You can't hear me if I am wearing a face mask. Keith

@@hardrockuniversity7283 Thanx Sir ure sacriface for us who have never get chances to learn the science.

@@qalbihodon721 Hardly a sacrifice, I enjoy it. Thank you for the compliment.

Thank you. Posting more recent videos in the same vein right now.

It doesn't have to be precise. Probably anywhere from 1/2 lb to 3 lb is good for most samples. It depends on how much you started with and more importantly, the particle size. If it is a coarse crush like from a jaw crusher or drill cuttings, a larger sample is better- the lab will crush it finer and then split it some more. My samples are of 30 mesh minus in this case, so 1/2 lb is probably sufficient, but more can't hurt. Keith

Pretty much. Considering how fine the material is, even half a pound is probably enough as long as it is a split and not a grab sample.

Sorry if I am missing something here but when you are talking about a "split" you are talking about taking a given weight of ore (say 200 lbs) then crushing and sorting out the cons tell you have 2-3lbs of high grade cons correct? Then sending those off for assay?

Sorry miss commented. Thought I was posting on lesson 4.

I sweep up the plate between samples. It is also a different matter when doing production testing vs individual samples whee you need to be more careful. In production testing you will often use multiple buckets of material and just split a representative sample for assay from the total material crushed. Good point. The 1/2" never deformed, but my hands got sore more than once banging against it. :-)

Coning and quartering work well, especially for small samples. For larger samples a splitter speeds things up quite a bit. I used them a lot while test hole drilling to get things from 50-150 lbs down to lab sized samples fast enough o keep up with the drill.

2 to 3 pound samples, we mostly process iron ore samples

2 to 3 pound samples works quite well quartering on a bench. The splitter is a great tool to get it DOWN to that 2 to 3 pounds. They also make micro splitters: but, as you know, they are not really necessary. May I ask where you work? Keith

i work in a mine, i live in india.. we mostly work with sampling of processed iron ore fines and lumps (+40mm to - 10mm) size, sometimes we collect samples of drilled holes on mine faces. but mostly we work on fines and lumps

It is good India has its own iron. It helps to keep jobs in the country. I know you have coal also. Do you have many base metals like copper?

In this case we are testing the extraction technique rather than the ore. How much gold is in the rock is not the most important question. The most important question is how much gold can you get OUT of the rock and at what cost. When the first run through gave me results that I was not happy with, I re-ran the test to see if it was due to an inherent limitation of the technique that would be hard to overcome, or simply an adjustment issue. I was mainly an adjustment issue and by making a few tweaks to the system I was able to significantly improve my recovery at essentially no cost. While it would not make any practical difference to this ore, in a profitable ore, it would add significantly to the profit margin. Keith

Hard Rock University thank you i understand now :)

You're welcome.

One of the easiest ways to deal with a sulfide ore is to make a concentrate and then just sell it to a refiner- possibly after removing the free milling gold. What is your approximate grade and tonnage? Keith

I'm still working on getting the assays done. Your contact in Idaho in Mullen I think? I'm going back through your videos looking for that info. You should start a service where you just analyze ore. Not really assaying it just crush and pan a sample to see if one is on the right track or not. Like yes that is free milling Gold and yes those are likely Silver Sulfides. Maybe identify the host rock etc. Then recommend the next step. I bet you'd be busy. Seems there'd be a niche between the Miner and the Assayer. Mine the Miners, sell them shovels kind of thing. I watched another of your videos for the second time and something major clicked for me on overlooked prospects. Your simplififed liberation test video is pure gold for those who get it. For me binge watching your video series was a bad idea. I missed some key points. I can't wait to get back up there. Take care

Yeah, learning can only occur so fast. Best to lock in one lesson before working on another. I tried to start them in a logical sequence but then had to simplify and amplify and it go kind of out of kilter. Oh well, if I was perfect, I'd be fishing right now... :-) I am most interested in helping to perfect mill and mining plans for people as opposed to simple sample analysis- although that will be a major part. Keith Keith

Chris Christopherson Inc, Kellogg Idaho

You are most welcome. I especially like to hear from people from other countries like yourself What is your native language if I may ask? I Ask question if was confusing. Keith

There are a couple of them: #1- I started the channel years ago as an informational platform that I could use to market a new separation table design I thought had merit. I hope I have the bugs worked out now, but I need more ore varieties and volume to test it on. Which brings me to : #2- The channel is an excellent way to meet people with properties and little to no experience/equipment, or physical ability- all of which I can supply for a cut of the action. And: #3- I really hate to see people part with their hard earned money due to unscrupulous promoters, uncaring ( and sometimes deceptive) equipment manufacturers, unrealistic expectations or assumptions, wishful thinking, or just plain ignorance based in inexperience. I know how much my money means to me and hate to see decent people learn the hard way if I can help educate them the easy way. Plus: #4 I am finding I enjoy it and the travel. So does my beloved wife. Keith

@@hardrockuniversity7283 Kieth thank you for responding. So many times knowing one's motivation makes such a difference wether you want to trust the information that they put out. I have always wanted to go out rock hounding or gold hunting but didn't know where to start. I greatly appreciate your in depth explanations.

@@ahorseman4ever1 You are welcome. Nobody ever asked me in a comment before. You seemed sincere and I had a little time, so I thought a proper answer was warranted. Often, I just go with my gut when there is no reason not to. Keith

My neighborhood is very informal. ;-)

@@hardrockuniversity7283 Oh. I'm certain you wouldn't be running that kind of equipment if it wasn't. I was just trying to be funny. I'm very much enjoying all of your videos, thank you so much for recording them.

@@PCMcGee1 You're welcome. Took me a long time to find a neighborhood this relaxed. Funny, I live in an old, run down adobe house less than a mile from downtown. There are horses on both sides of me. Funny, eh?

The rolls in the RC 46 will not. It will squish them down into something like a coin or foil, but won't tear them up. That is why when I am using it for production pulverization, I keep re-grinding the oversize until it passes the screen to get on the table, or else pan the little remaining oversize at the end of the day. An impact mill will tend to tear things up, but even then a large nugget will usually just get beat up some and then settle into a dead space. It might be in a few pieces, and it certainly will no be jewelry grade anymore, but it will not be lost.

Excellent. Unfortunately, the very fine gold in hard rock usually won't set off a metal detector until it is VERY rich.

Hmmm... Good idea. I don't know how to insert a link though. I'll see if a techie can show me how. The address is : kzfaq.info/get/bejne/bt5gi9CLrq_XZ40.html

They wouldn't hurt. The sound is much less than others I have been exposed to. so I am a bit lax. The mask was so you could hear the narration. What you may not perceive is the pattern of holding my breath when the dust blows my way. Not as good as a mask, but useful in this situation.

True, but I was also using invisible techniques such as holding my breath at times and staying out of the actual dust cloud and breathing through my nose for filtration. I guess they are bad habits, but I was trained MANY years ago when safety was much less of a concern. Some of that was because small exposures were not recognized as unsafe as they are now viewed. Thank you for emphasizing the point. Keith