Significant research has been conducted in the past to evaluate the application of hindered-bed settling devices for achieving efficient particle size classification. However, recent studies have been devoted to the interest of using the hindered-bed devices as gravity-based separators for multi-species suspensions having wide density differences between the various particulate components. The ability to achieve … Read more
Several preliminary tests were conducted as a function of drum type (standard, interpole, etc.) and feed temperature. The results from these tests indicate that the deep field of the salient-pole drum vastly outperformed the other magnetic drum circuits. As a result, continued test work focused on the salient-pole drum and rare-earth roll separators. Initial tests … Read more
Pulsed columns, like other pulsed columns, consist of an active column section with decanters on either end. Test columns are usually in the 40 mm to 150 mm diameter range and the decanters are typically twice the diameter of the column. Commercial columns can be up to 3 m in diameter with 6 meter diameter … Read more
Interests in the hydrometallurgical processing of primary sulfide concentrates have revived because leaching in chloride media is rapid and is capable of recovering sulfur in elemental form, and also because rapid advances are being made in corrosion-resistant materials. A process is proposed which consists of low-temperature chlorination and selective oxidation of chalcopyrite concentrates to produce … Read more
Strain relief measurement techniques were used to quantify stress in the underground pillar and to compare stress relief to seismic and ultrasonic core velocities. These measurements represent a single point. The procedure for measuring strain relief (Girard and others, 1997) consists of — Drilling a hole 152 mm (6 in) in diameter to a pre-selected … Read more
It is also fairly well-known, that it is by far much more difficult to achieve high efficiency with dry classifying than with wet. Hence, it is highly desirable to create conditions for improving the dry air classifying methods, so that the high energy consumption associated with producing fine dry powders can be minimized. Particle Size … Read more
The principle of the sample flows of the analyzer system is shown in Figure 4. As the analyzers are located in a separate room, many of the primary lines require pumping. The samples are returned mostly by gravity to the corresponding process pump sumps. The primary sample lines have a diverter that feeds the stream … Read more
Alternative reagents for gold leaching include thiocyanate (SCN-) and thiourea (SC(NH2)2). They are considered less toxic and more environmentally acceptable when compared to cyanide. One of the important features of thiocyanate and thiourea dissolution of gold is that the leaching can be performed in acidic media, enabling the use of soluble oxidizing agents, such as … Read more
After filling the column with water, the teeter water flow rate was set to produce the desired cut size. The feed water was adjusted to produce a feed slurry consisting of about 50 percent solids by weight The screw-feeder was then set to the desired rate. Solids were fed into the feed tube and combined … Read more