Blogs

Evaluating Copper Rougher-Scavenger Flotation Circuit Grade/Recovery Results

A modal examination of the products produced by the copper flotation rougher-scavenger circuit reveal important information regarding the limits to the efficiency of the process, imposed by mineralogy, fragmentation and flotation capacity.  Let’s discusses various aspects of rougher flotation circuit performance and how to evaluate its results .     Prior to compositing the individual downbank rougher and scavenger cell products, for

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Mineral Composition and Fragmentation

Table of ContentsRandom Sets and Integral Geometry in Comminution and Liberation of MineralsApplications to fracture of mineralsApplications to liberation predictionOre breakage modellingA Combined Size Reduction and Liberation Model of GrindingModel DevelopmentExperimental Procedure The metallurgical response of minerals during the flotation process are dependent upon two factors: The fragmentation of the minerals from each other during the grinding stage establishes the

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Flotation Process Development and Assessment

At a mining operation, a project was designed and implemented to develop a process for controlling lead recovery in the flotation plant. The metallurgical program consisted of two parts: A survey of the current plant process streams was conducted first to assess the performance characteristics of the existing flowsheet and equipment. A comprehensive program of laboratory scale metallurgical studies was commenced on

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Balance Chemical Torsion

BALANCE, Chemical, Torsion—Capacity, 4½ kg. or 10 pounds. Sensitiveness, 1/6 gram or 2½ grains. With nickel plated brass pans, 9 inches in diameter. Finished in black japan. Suitable for mortar mixes according to A. S. T. M. and Cement Reference Laboratory specifications. Beam graduated to 500 grams in 5-gram divisions. Beam graduated to 16 ounces in ¼-ounce divisions. BALANCE, Counter Scale—Capacity,

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Pulp and Bullion Balances and Scales

BALANCE, Pulp—For weighing ore, bullion and pulp samples, etc., for analysis. Rigidly constructed. Brass beam. Beam release of standard eccentric type. Gold plated steel knife edges and agate planes. Removable, nickel plated brass pans. Mounted on polished mahogany box with drawer which will accommodate the balance mechanism. With level and leveling screws. BALANCE, Pulp—For weighing ore, bullion and pulp samples, etc., for analysis.

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Analytical Assays Balances

BALANCES, Assay, Keller Type 38—A high grade parts gold plated. SPECIFICATIONS: Capacity: 2 grams. Knife edges and bearings: Agate. Sensitiveness: 1/200 mg. Indicator deviates 2 in dex divisions, each 1/20 inch wide, with 1/10 mg. change of load. Releasing mechanism: Fall-away type. Smooth and gradual in operation. Period of oscillation: 11 seconds. Pans: Nickel silver, black interior. Beam: The design of the beam gives

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Sub-Sampling of Pulverized High Grade Gold Concentrates

The impressions in the second and third rows record a potentially biased sampling method.  The Vee shaped cuts took most of their volume from the top, and almost nothing from the bottom of the pancake.  This explains why periodic critical review of sampling at smelters is a good idea.

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Gravity Borax Method GBM Mercury Free Gold Recovery

The Gravity-Borax Method GBM is still unknown  to most Artisanal and small-scale gold miners (ASGMs) worldwide as most still use mercury to extract gold. “Whole-ore amalgamation” is a technique that requires the use of 10–25 g of mercury to produce 1 g of gold. Within the last eight years, it has become evident that this technique is more widely used than earlier anticipated,

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Abandoned Mines

This information system forms a World Map of Abandoned Mines all around the USA.  Zoom in/out and click on a “metal dot” of your choice to view the details of the related Abandoned Mine Listed by the USGS. 64,883  Inactive U.S. Metal Mines as of 2012 This map represents inactive metal mining operations across the United States. This map does not include any mines

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Typical Reason to Replace a Ball Mill Trunnion ‘unexpectedly’

What is the typical reason a ball mill trunnion needs to be replaced unexpectedly? It is unclear if the trunnion damage was known ahead of time and planned for a change-out during the shell reline or if it was discovered during the reline work. While, not knowing if this is the feed or discharge end trunnion, there could be a number of

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Selecting or Choosing a Lab Flotation Machine Model

The model’s choice of a laboratory flotation machine depends on three things; What work you want to do with the machine Who you have to operate the machine How much you have to spend If its just for some ‘hot’ plant floats and some basic metallurgical testing onsite then my personal favorite is the old Denver D12 machines. They are

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Effect of Feed Rock Size Distribution on Crusher Performance

If the ore feed to any gyratory or jaw crusher consisted entirely of large cubes or spheres of a size that would just barely enter the crushing chamber, the crusher could not be expected to produce anything like its normal rated capacity because the upper part of the crusher could not shatter the large pieces enough to keep the rest

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Low Molybdenum Recovery in Copper-Moly Flotation Circuit

In a flotation locked cycle test, a poor/low moly recovery was obtained at 47.3% as it appeared that molybdenum had not reached equilibrium. The calculated head grade trend, shown in Figure 8-28 indicates that the moly and most of the other elements had not reached convergence when the test was terminated. Figure 8-29 shows the trend in recoveries as the

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How To Use Mercury To Recover Gold

Forever and ever, mercury has been used to recover gold, fine gold in particular.  When it comes to chemicals like Hg, one must be careful. THE DANGERS OF MERCURY AND NITRIC ACID Mercury and nitric acid can kill if swallowed. Nitric acid can be absorbed through the skin, causing nitric acid poisoning. WEAR RUBBER GLOVES! We recently reviewed a list

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Separating Gold And Silver Dore Bars With Nitric Acid

A dore bar is the metal that comes from the slag that has been fired and cooled. Place dore bar into a crucible. Fire in a furnace or oven. When using a muffle furnace, fire on high. It is ready when the metal is melted and looks like honey with no lumps in it. Pour quickly into a five-gallon bucket

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Recovering Silver from Photographic Materials

The Dangers Of Nitric Acid Nitric acid can kill if swallowed! Nitric acid can be absorbed through the skin, causing nitric acid poisoning. WEAR RUBBER GLOVES! Always use nitric acid in a well-ventilated area. Do not breathe the fumes! Nitric acid can ruin your clothes and shoes. Always add nitric acid to water. Never add water to nitric acid! Always

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How To Use Aqua Regia To Purify Gold

THE DANGERS OF AQUA REGIA:  When adding aqua regia to ore, there can be use a red gas given off; THIS RED GAS CAN KILL Sometimes the ore will bubble over, so watch it carefully. Use the aqua regia in an open area and it to the ore very slowly. Aqua regia cannot be boiled or simmered in the house

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Fluxing And Smelting Silver Ore

Equipment Used For Firing/Smelting Ore Furnace Or Oven For Firing/Smelting: It must heat to 1950 degrees F for gold and 2100 degrees F for silver. A muffle furnace is best. It fires to about 2300 degrees F and the ingredients can be easily added to the ore while firing. Crucible: Clay or graphite crucible to use in a muffle furnace. Other types

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Nitric Acid To Purify and Separate Silver/Gold

THE DANGERS OF NITRIC ACID Nitric acid can be absorbed through the skin, causing nitric acid poisoning. WEAR RUBBER GLOVES! Nitric acid cannot be boiled or simmered in the house or where it is not well ventilated. It causes nitric poisoning. You will hurt in every joint of your body and it can kill you. Nitric acid can kill if

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How To Clean Gold with Nitric Acid

Gold acts like a sponge and absorbs nitric acid. This enables the nitric acid to clean the gold, such as gold nuggets or free gold taken from black sands. Most gold found in nature contains other metals, but some of these cannot be taken down in nitric acid (such as the platinum family). First; The Dangers of Nitric Acid Place

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