Advice needed on percentage question .

Hi all ,

I've made a dry concentrator that can reduce down 25lbs of material to one lb ( 10 kilos to less then 500 grams ) in about a minute on the first pass .
What I need to know is the percentage of reduction that equals ? just have a mind block at the moment on the maths :8

Also is that considered a good reduction target ?

Been making proto-types since 2013 , trying to get the ultimate quick hand cranked design that can retain all the gold from dust up .

This was last years best performer , 7 or 8 turns clockwise then turn anti- clockwise to dump the lights .

On those figures you're reducing your material down by 95-96% Jack. Pretty good I'd say.

interesting concept .. Hows the concentrator work mate ? .. You dont have to spill design 'secrets' or anything, just a basic run down be cool.

Thanks mbasko for the percentages & ballarat_gold for your input .

Further to BGs question , I took a wrong turn that cost me a whole years work trying a design that could never do what was required .
I did some study online to figure out what was happening with the dirt/gravel , one of the sites that helped me overcome years of flawed ideas was this :
https://books.google.com.au/books?i...nular media : between fluid and solid&f=false

I now have a working model that can retain the fine gold & up , will also process twice the amount of material with far better efficiency .

Thanks for your interest
jack .

To much math for me

This model was a previous design , had a self adjusting internal system & did work ' but not enough for me .

Where is the buy it now button?
What's at the back, I'm already wondering how to motorize it.

Looks like people power with handle at front.

Gee, makes you wonder why the old timers didn't think of that? Just think, you throw in the dirt, rotate it by hand a few times, and you have 90% of the gold just waiting to be scooped out.Wow!! And all this without water?

Hi Outback,

The process for calculating percentage change is

Step 1: Divide the New Value by the Old Value (you will get a decimal number)
Step 2: Convert that to a percentage (by multiplying by 100 and adding a "%" sign)
Step 3: Subtract 100% from that

So in your example 500/10,000 X 100 -100 = 95%

There are a number of ways to calculate it, but this is the easiest to do with a calculator.

Thanks for going to the trouble Dr Duck , I can understand that

Outback, this what we were talking about way back when???

Looks the goods!

I'd a gone 25 to 1
425 = 100
So 41 = 4
Id'a come up with 4%
And 100 % to 4% = -96%
:Y:

I might be misinterpreting but maybe step 3 should be:

Step 3: Subtract that from 100%

100% - 500/10,000 X 100 = 95%

When I think of stuff like that I reduce it to simple terms like 10kg original reduced to 1kg left so I have 1/10 left or 1/10 X 100=10% left

So %left = left/original x 100
and %reduced = 100 - %left

So to work out reduced it is %reduced = 100 - left/original x 100

Plug in your numbers:

%reduced = 100 - .5/10 x 100
= 100 - 5
= 95%

But you should always check it with something which is not an even percentage so to get confidence try something different:

3kg sample reduced to 1kg which is 1/3 left or 2/3rds reduced and 2/3rds of 100% = 66.7% reduced so:

%reduced = 100 - 1/3 x 100
= 100 - .333 x 100
= 100 - 33.33
= 66.7%

The thing to remember as well is to always convert everything to like terms such as kg or grams before any calculation like drduck did.

Jon

Potbelly11 said:

Outback, this what we were talking about way back when???

Looks the goods!

Click to expand...

Sorry Potbelly but I've forgotten :8 can you elaborate more please .
jack

Couldn't sleep (not knowing if I was right or wrong), there being an alternative answer being proposed and all.
So.... here's the calculator for the job
http://www.percent-change.com/
and here's the screenshot of the calculation done.

I'm just glad my minds eye was on the ball enough to see it simply for how it was. :/
I love my subconscious (and trust it impeccably), after all, it's all I got. :Y:

Silver that is impressive ! :Y:

Thanks
jack.

Outback said:

Silver that is impressive ! :Y:

Thanks
jack.

Click to expand...

Well I did have a couple of pretty good teachers in my life Jack.

Along the lines of what Silver is doing here's another way:

10 : 0.5
Multiply both sides by 10 to get original sample to 100

100 : 5
So 5% remaining or 95% reduction.

Drduck 3. is correct %change vs %reduction my terminology was wrong :Y:
Jon

Hey Jack,
I remember you did have a screen on an earlier model to classify a bit, just wondering do you shovel all gravel into this unit or do you need to classify a bit?
cheers
Lee