Bioleaching Carbonaceous Gold Ores

The previous tests demonstrated the use of facultative and extreme thermophiles for refractory sulfide gold ores and flotation concentrates. The following tests were conducted on carbonaceous gold ores to evaluate response to bioleaching. Facultative Thermophile Bioleaching of Carbonaceous Gold Ore The facultative thermophile S1I was used to pretreat a carbonaceous gold ore under CSTR conditions. … Read more

Flotation Training

Timed Flotation Test & Cumulative Grade Recovery Curve Mineralogy & Flotation: Floatability VS Selectivity Test Assessment Flotation Kinetics: Mass & Water Recovery VS Entrainment & Mineralogy Laboratory Flotation Testing

Cyclic Voltammetry

A few representative cycles from the first 20 oxidation/reduction cycles for a pyrite electrode in 0.1 M sodium borate are presented in Figure 3. The first scan was made in the cathodic direction starting from the rest potential of the mineral which typically had a value of 0.18 V. The large reduction peak observed in … Read more

Pyrite Buffer in Soil

The Gunnison, Colorado, tailings provide an example of the chemical reactions across the interface with soils rich in pyrite but low in calcite. In this case, the retardation of trace components is determined primarily from the Eh controls and less from the pH (Johnson, 1985). The compositions of groundwater from wells in the vicinity of … Read more

Effect of Cupric Ammine on Gold Dissolution Rate

The dissolution of gold in ammoniacal solutions cannot take place in the absence of oxidants. Cupric ammine can act as an oxidant in this system according to Equation 3. The effect of cupric ammine concentration on the dissolution rate of gold was investigated in a solution of 0.6 M total ammonia concentration (0.1 M (NH4)2SO4 … Read more

Autogeneous Grinding VS Steel Grinding Media in Flotation

In grinding, the use of steel media in a rod/ball mill circuit clearly diminishes the subsequent froth flotation performance over purely autogenous grinding. The use of recycle water in grinding also clearly diminishes the subsequent froth flotation performance associated with fresh tap water. Some of these flotation deficiencies are recoverable by using stronger collectors at … Read more

Magnesioferrite

In the case of pellets it was observed that incremental additions of olivine to any of a series of pellet concentrates invariably caused the pellets to become progressively more ferromagnetic after induration. At first, it was assumed that what little magnesioferrite formed in such pellets stabilized magnetite, a comparable spinel structure, in solid solution. However … Read more

Small Cone Crusher

From the discussion so far it is obvious that two energy factors determine a crusher’s productivity: (1) Total power drawn affects the quantity produced of any given size or range of sizes. (2) The energy applied, previously defined as the crusher’s Power Rate (kilowatt hours per ton of feed) will determine the size reduction. This … Read more

SAG Mill Components

Once the basic operating conditions have been defined for the mill designer then, and only then, can he begin taking into account shell and head stresses and trunnion bearing sizes required to carry the load and to give the required openings for feeding and discharging the mills. Mill heads are key structural components of any … Read more

Heavy Minerals Sands Processing by Rare Earth Magnets

The first known attempts to apply a REM roll separator to a heavy mineral sands application were made in South Africa and Western Australia in 1985. At that time, an ilmenite beneficiation process, which was normally achieved with cross-belt separators, was tested with a full-size machine. The performance was not good because only a single … Read more