Advice needed on percentage question .

[Outback]

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 .

 

[user 4485]

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

 

[ballarat_gold]

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

 

[Outback]

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 .

 

[ballarat_gold]

To much math for me

 

[Outback]

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

 

[Occasional_panner]

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

 

[HarryHoudini]

Looks like people power with handle at front.

 

[graybeard77]

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?

 

[DrDuck]

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.

 

[Outback]

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

 

[Potbelly11]

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

Looks the goods!

 

[silver]

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

 

[blisters]

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

 

[Outback]

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

Looks the goods!

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

 

[silver]

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:

 

[Outback]

Silver that is impressive ! :Y:

Thanks
jack.

 

[silver]

Silver that is impressive ! :Y:

Thanks
jack.

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

 

[blisters]

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

 

[rc62burke]

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