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Started by Alex
We are currently setting up an Alluvial Gold Wash Plant - (Hopper bin - Vibrating Feeder - Trommel Scrubber - Sluice Box - Vibrating Screen (2mm) - Falcon Concentrator) We want to process the 75 tons per hour. The clay content is high. And the mat...
Last replied to by Deano
I assume that you have a 300mm wide ring at the bottom of the scrubber section to retain the feed. You would want to have 4 slotted 150 wide lifters on the ring to keep the oversize moving through th...
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Started by Tariq
I ran 6.11% copper oxide on a shaking table optimised to process chromite ore, and got 10.60% in heading, and 4.28 in middling. Copper was milled at 100 plus mesh. There was no control and hence no optimisation. How much say 1% copper ore can be upg...
Last replied to by David
Tariq, do you have the weights of those streams?
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201
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Started by vekian
We have 2 discharge pipes from the cyclone underflow. 1 is a smaller diameter pipe going to gravity/scalping screens which then classify the product. Oversize from these screens report to mill discharge hopper. Undersize reports to gravity concentrat...
Last replied to by David
vekian  I'd be interested in this. Do you have answers to Paul's query?
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Started by Sachin Prakash
Why were copper plates used historically for mercury amalgamation = rather than other metals?  it's always copper.  Thank you
Last replied to by Hauptsturm
Mercury is attracted to copper. The mercury is dispensed down a long copper table, which formed a thin coating of mercury on the whole table. This creates a mercury-wetted copper plate. The gold ore w...
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Started by Alex
We are looking for an efficient Nugget Trap design. Alluvial Gold Wash Plant - 75 tons per hour. Anyone has a proofed efficient design? We found some on internet, but not sure if they are really effective.
Last replied to by Deano
Looking vertically down at a piece of expanded metal sheet the diamond shapes are 3" long by 1.5" wide. The depth of the holes is controlled by the thickness of the metal sheet before treatment, depe...
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148
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Started by terrence
i am using spirals to recover chrome fines size (-1mm) to (+100microns) from ore. l have noticed a high grade and reasonable amount of values in the tailings and after size analysis a majority of these fines are in the range of (-75microns). How can ...
Last commented on by B T Chitapa
Most of the gravity concentration equipment have limited performance on material below -75microns and you also have quality issues if that material has a constitution of more than 20-30% in the feed t...
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89
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Started by Anupam
Can you explain recovery and recovery rates?  Say I am jigging mineral, I get a 60% recovery rate. feed specific gravity is 3.8, final product gravity is 4.2.  If I lower my recovery rate to 50%, what will happen? maintain final specific gravity, b...
Last replied to by Anupam
My thinking was therefore correct. To explain, my boss asked me what if I dropped my recovery. I asked him why, and that if it is to increase quantity, the final product S.G. will certainly drop, (as ...
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Started by explorer64
We sent a substantial amount of quartz gold ore to a mill for processing. After a couple hundred tests on the material an average grade was calculated. After milling for several days the mill says there is way less gold in the ore than what had bee...
Last replied to by David
Funny how Treve here posted photos of a Mozley Multi Gravity Separator to recover gold ... do you see the ball mill parallel? 
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Started by Bill Rico
What method would be best to use for the washing of coal tailings having ash of ranges from 45-54um
Last replied to by Treve Mildren
The old Mozley MGS certainly wasn't worth consideration due to its inability to pull sufficient material to concentrate. Development work by Gravity Mining ltd in conjunction with the Camborne School ...
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357
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Started by Zander Barcalow
I'm looking for methods of industrial processing of titanium ores which follows the initial "gravity separations".
Last commented on by Treve Mildren
I would say we had more than a few issues with the MGS and corrosion. But yes by using more suitable materials such as hastelloys in the wetted areas the MGS would be an ideal tool. Millenium Chemical...
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156
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Started by Mr. Nanda kishore
if jigging can process galena ore, which information is necessary e.g mineralogy, feed size, feed, jigging machine type etc. ?
Last replied to by David
Hello Mr. Nanda, unless this is a research project or you are under some serious environmental restrictions, you would not jig galena. Mr. Skinner is correct in saying flotation is the best galena re...
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668
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Started by Latricia Patton
We always come across some customers who want to  concentrate the alluvial gold . And their alluvial gold is with some magnetic mineral,so some magnetic would stay with after gold centrifugal or jig separator . below is the flow offer by some suppl...
Last replied to by Khosana
Hi there, I would suggest that you perform mineralogy studies first before you could rule-out the use of magnet separation.  
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1657
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Started by Gabriel
I will buy a centrifugal gravity concentration. What is better? Falcon or Knelson?
Last replied to by Jorge Quintanilla
Many years ago I was involved in a technical comparission between Falcon and Knelson. In that particular case, the winner was Falcon , I don´t know, may be in other mines is different. I have a pers...
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Started by spaceexplorer
We are considering acquiring an iCON-i350 Centrifugal Concentrator ( http://www.iconcentrator.com ); a Falcon SB350 equivalent. However, we got an attractive offer of two units of “Oro Low-G 16” Horizontal Centrifuge Primary Concentrators” (use...
Last replied to by David
Yes, if you have no gold finer than 200 mesh (74um) you might be OK with that low-G machine. Otherwise.... you need high-G for better recovery of fine gold. Can you perform that type for test? Belo...
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401
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Started by Olga
Hello colleagues! Does anybody has an experience with tube densifiers in a dense medium circuit? The picture of densifier is attached.  What are the advantages? Is it possible to set up usual thickening hydrocyclones? What are the differences? Wh...
Last commented on by Olga
Richardh, thank you very much for the reply!
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Started by Wattle01
Hi I'm currently working Placer gold a Quarts Conglomerate, I'm washing in a Trommel, 100 x 15 liter buckets ( soaked over night) in a day 5 days a month.... I have a limited amount of water. I'm wondering if I made a bigger Trommel to wash the 500...
Last replied to by dk
You may use the same existing  system  if required with lower rpm and necessary lifter bars for scrubbing and increase the retention time. The processed water may be taken to 2/3 compartment tanks f...
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737
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Started by NAVEEN VARMA B
Myself mineral processing engineer and am working on flow sheet development.... Am getting problem with maintaining circulating load in spiral concentrator circuit (rougher, scavenger & cleaner) followed by hydro cyclone? As we are giving hydro cyclo...
Last commented on by dk
For balance loading and recovery of desired quality, sample may have to be tested with two stages classification in cyclones, changing the operating variables in the 3 stages for optimum loading of sp...
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494
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Started by anjanisail
Dear All While preparing Flow Sheet for designing of a flow sheet for beneficiation of Hematite Iron Ore, I came across a Problem. I have considered Jig, Spiral Concentrator and WHIMS in my envisaged flow sheet. Based on the available test test resu...
Last replied to by Marshal Dienes
AS YOU MUST KNOW, One of the biggest mistakes in designing a process flowsheet is designing for an "average" ore that will never actually be seen. If Pilot Plant work is done, a range of ores should b...
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438
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Started by Tarun Karakoti
We run a Gekko ILR to leach gravity gold. The problem we have is to estimate the Au recovered using Solution assays & tons from volume measurements. The variation is always approx. -30%. Where are we missing?
Last replied to by Tarun Karakoti
What are the best automatic sample cutters for the solution streams?I think the problem with solution accountability has been identified. It was due to interference with Fe ions with the use of AAS di...
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365
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Started by Jean Rasczak
Could Gravity + Intensive Leach process the Gold in more cost effective manner? Some study in stopping the illegal miners using mercury claimed this opportunity too. Some junior miners samples of Indonesia, showing > 100 ppm Au in the GRG concent...
Last replied to by Hauptsturm
It is good to see you describe the research he has conducted concerning the use of glycine for leaching copper (1 paper) and for leaching gold and silver (2 papers). We look forward to their demonstra...
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492
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Started by Marshal Meru
Within our concessions have abundant tailings (2% Hg and 10 oz Ag/TM), waste from the extraction of mercury from cinnabar, they have potential silver content. What would be the ideal method to benefit them?
Last replied to by Marshal Meru
The raw materials are sandstones with contents of cinnabar, which are the result of the processes of recovery of Hg retorts used by the Spaniards for the 1700. Silver is found as native. So the idea i...
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320
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Started by Helena Russell
How low can your solid tails go?Low grade ores ranging 0.6 - 1.0 g/t Au (silver ignored), Low Cu (25-50 g/t0Gravity- CIL circuit gold processing plant.
Last replied to by Sturmbann
There is no magic number. It depends on the mineralogy of your ore and the efficiency of your process. When I was the plant met at the Tarmoola mill, we went for a week with no measurable gold in the ...
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244
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Started by Amar
Just wondering if there is a better way, environmentally, to reprocess mercury-rich gold tailings other than using a retort! The tailings belong to an old Whole Ore Amalgamation process at a saprolite deposit.
Last replied to by Amar
Gravity Concentrators can only recover about 60-70% of the mercury at best.
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Started by Bob Mathias
When it comes to very fine gold recovery in alluvial operations where throughput volume and continuity are very important, what are the top priorities to consider?How important are say Corey factors, make up of host gravel/sands, gold finesse, clear ...
Last replied to by Bob Mathias
We are indeed doing that. Beyond the knowledge and experience you get by hiring one professional, forum like this may provide different ideas to consider, debate and try in practice. I think starting...
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238
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Started by Carl Jenkins
Anyone experience any significant correlation between feed rate and grade/recovery in GRG concentration test work?If we run 50kg batch, 20 kg batch, 2 kg batch with similar feed rate and other parameters, anyone experience any significant difference ...
Last replied to by Alan Carter
Totally agree with all the above. The nugget effect calls for a larger sample size. Start-up and shutdown effects will bias results so the longer you are at steady state, the better.You need to think ...
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Started by OberstGruppen
There is any specific reaction, to describe the process of amalgamation of gold?
Last replied to by Marshal Dienes
Just straight physical dissolution as sugar dissolves in water. The gold SG is 19.3 and the mercury SG 13.6 if you would take a gold concentrate and assume it is liberated largely from a host like sil...
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Started by Tony Verdeschi
We have a heavy mineral sand project and we would want to use standards samples. Most of our analyses are done by heavy liquid separation to get the Total Heavy Minerals (THM). For now, we use a homogenized bulk sample for our standards but it’s n...
Last replied to by Tony Verdeschi
Thanks for the answers.After having checked the above proposed solutions, I finally checked with the lab in charge of the standards for our Canadian open pit operation and they said that won’t be a ...
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210
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Started by Carmen Ibanz
"Diamond Soaks" for Separating Precious Metals from Precious Stones: Are There Any New and Efficient Methods Better Thank Aqua Regia Then Sieve Shakers? This is a process for recycling by separating precious stones from gold, silver, the platinum gro...
Last replied to by Marshal Dienes
You can use AR with ultrasonic, this will help in agitating impurities so that you have better results separating Au from other metals. Properly alloyed metals should not dissolve and leave behind lar...
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234
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Started by Standartenfurer
We have a placer gold mine in the remote area, the grade is 0.3 ppm and the reserve is 30 million tons. We do not have water and maximum recovery with Knelson is around 40%, can anyone help for processing?
Last replied to by Standartenfurer
We are working on characterization tests and will inform you the result shortly.
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435
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Started by Carmen Ibanz
We are giving feed to Rougher spiral with 58.8% Fe, Concentrate yields 60% along with 63%Fe, Again this material is sending for Second stage treatment (Cleaner stage) here its producing 64.2%Fe. But, total tailing from Spiral Circuit contains 55% yie...
Last replied to by Obergruppenfuhrer
I appreciate your response and that you are planning to try out the tests suggested. If you do require a plant audit then our company CDE Asia Ltd could be of service. We have an agreement with GHD of...
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313
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Started by Sugar Watkins
Is it possible to gravity concentrate a gold dump during the rainy season using sluices taking advantage of the natural drainage system?
Last replied to by Sugar Watkins
1. Size approximately 300tons no characterisation has been done yet. At lower levels visible Au is observed on panning. There is also a low grade 0.43g/t Au gravel of unknown tonnage in the area. 2. S...
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339
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Started by Bob Mathias
The video shows one that was shown last year at electra mining. It gives some idea on how it works I just wonder how this can be applied to different mineral ores? What is the discriminatory edge with this method? Meaning how different must the dens...
Last replied to by Bill Rico
Rock of 3.0 g/cc can be separated from rock of 2.0 g/cc. Separating 3 cm2 rock from 4 cm2 rock would be a classification process using screens not spirals. https://www.youtube.com/watch?v=O64USKI_UDs
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Started by Carl Jenkins
Might is be for base metal recovery by flotation or gold by leaching and flotation, a Mobile and Modular Process Plants only use to be a thing of the pass... no more. While gold and other placer operations (diamonds) are the big users in numbers of ...
Last replied to by Carmen Ibanz
The old Yuba Manufacturing company which operated from the late 1890's to about 1960 built many floating dredges that also include a gravity circuit on them. I used to have a picture showing four or f...
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245
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Started by Zander Barcalow
Can any body tell me cut- off grade of Tantalum in alluvial deposit for economical mining &processing. Tantalum present in alluvial deposit in the form of Coltan.
Last replied to by Dizzy Flores
Cut-offs around 150-200 pp is an industry standard to look out for, below this, you may be wasting your time. The above comments are all true. On alluvial/eluvial - overburden depth is critical. On ha...
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Started by Marshal Meru
The performance of Churn Drills on wet alluvial merits some discussion as I agree that Churn Drills are EXCELLENT on DRY-ISH ground (terraces, small creeks, paleoplacers etc) but USELESS on WET ground such as floodplains or below water tables. Possi...
Last replied to by Zander Barcalow
Whenever people suggest applying factors to assay numbers they are implicitly admitting they have sampling problems. When you use holes drilled by different machines, each producing its distinctive di...

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