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 […]
Ball Mill Scale-up Method
Ball Mill Scale-up by this method is known as collision energy based population balance model. The appropriateness of this model is shown for 38-cm ball mill. Comminution in ball mills account for a significant amount of power consumption in mineral processing plants. Therefore, accurate modeling of the process is extremely important to optimize the power […]
Copper Activation Sphalerite & Xanthate
Copper Activation Sphalerite & Xanthate: Unlike most other sulfide minerals, sphalerite responds poorly to short-chain thiol collectors. The problem is attributed to the high solubility of zinc-thiol compounds in water. Also, due to its large band gap (3.7 eV), sphalerite is a poor catalyst for mixed potential reactions between xanthate and oxygen. The reactivity of […]
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 […]
Gold Pyrite, Pyrrhotite and Arsenopyrite Recovery
One of the more common classes of ores containing gold is when gold is associated with pyrite, pyrrhotite, and arsenopyrite. This is the area of gold recovery that has probably received the most research and plant optimization support especially in light of the long history of South African industrial practice. From a reagent viewpoint, charged […]
Dense Sludge Process
Figure 1 presents a simplified process flow diagram of the Dense Sludge process. The most significant change between Dense Sludge technology and conventional metals treatment is the method by which the alkali source is added. In conventional treatment systems, the alkali is added directly into the influent to achieve a desired pH setpoint. Generally, that […]
On-Stream Analysers Benefits
What are the benefits of having an OSA on-stream analyser? The assays are utilized for control in many ways, starting from individual control loops to overall optimization in the flotation circuits. Reagent dosages in the cleaner flotation stages are controlled by feedback from concentrate quality. For instance, the depressant in the zinc cleaner circuit is […]
Carbonaceous Gold Ore Treatment Method
Flotation The simplest method of treating a carbonaceous ore is the method described by R. W. Nice (1971) at the McIntyre Porcupine Mine where the carbon, which contains very little gold, is floated off and discarded. The remaining ore is then responsive to cyanidation. This does not work at Carlin because the carbonaceous compounds have […]
Thiourea Silver Leaching
Unlike base metals which are readily soluble in mineral acids, noble metals like gold and silver require the presence of oxidizing and complexing agents for dissolution. Silver approaches base metal behavior in acidic thiourea solutions (Ag + 3Thio ↔ Ag(Thio)3+ + e, E° = 0.025 V) requiring only mild oxidizing conditions for dissolution. Accordingly, the following […]
Ferrosilicon Powder
Ferrosilicon powder (containing approx. 15% Si) for constitution of heavy media is used today in many separation plants treating iron and other ores. The production of the powder by grinding is expensive. A new process atomizes the still molten ferrosilicon by air or steam. In a heavy medium this atomized ferrosilicon powder has several remarkable […]