Floatability of colemanite was determined using a 150-ml column cell (25 x 220 mm) with a fine fritt and magnetic stirrer. One gram of sample was conditioned in 150 ml of a solution containing SDS for 10 min. and floated for one min. using nitrogen gas at a flow rate of 50 cm³/min. The microflotation … Read more
Non-swelling calcium montmorillonite is mined from bentonite deposits and treated to produced acid-activated powders and granules for use as separation products and catalysts. In particular, acid-activated montmorillonites are used as sorbents for removing impurities from fats and oils, as catalysts for mineral oil processing and for a number of other applications. These smectite group minerals … Read more
The increased use of flotation columns is due to their superior separation efficiency compared to conventional flotation. This increased efficiency can be attributed to: The countercurrent movement of slurry and air bubbles increases the probability of bubble / particle attachment. This is accomplished by larger aerated volume of the cell, longer concentration gradient between froth … Read more
Many investigators showed that mineral flotation can be described as a first-order process (Sutherland, 1948; Tomlison and Fleming, 1963). In this case, the rate of flotation can be represented by: dN/dt = -kN……………………………………………………(1) where N is the number of floatable (or hydrophobic) particles present in a flotation cell and k is the rate constant. It … Read more
Recently, a number of techniques of recovering Palladium have been developed. For example, leaching of platinum group metals from spent automobile catalytic converters using halogen salt with oxygen was developed. Ammonia is an inexpensive lixiviant used in leaching precious metals such as silver and gold. Since palladium has some similar chemical properties to silver, it … Read more
Chalcopyrite is the most abundant mineral of copper sulfide minerals and the major source of copper. Numerous leaching processes, such as ammoniacal systems, acid sulfate systems, chloride systems, and nitrate systems, have been introduced and investigated. In oxygenated ammoniacal solutions, chalcopyrite dissolves according to the following reaction: CuFeS2 + 4NH3 + 17/4 O2 + 2OH- … Read more
As shown in Figure 1, there are other accessory vessels (splash and flash towers) in the autoclave circuits, that are also brickwork lined. The linings used to date, other than small test sections, have all been acid-resistant fireclay bricks, bonded with alkali silicate mortar, PbO-based mortar, and/or vinyl ester mortar, but mainly alkali silicate mortar. … Read more
The calculation of the performance of coal washing units that are in common use is not difficult and the principles of making such calculations have been known for many years. The flowsheets to be simulated consist primarily of coal washing units each with a target specific gravity of separation specified for each washing unit. The … Read more
To understand interactions between physical and chemical variables, a synthesis rather than an analytical approach is needed. In analytical approach, sub-processes of a system are isolated to determine the cause and effect relationships between performance of the sub-process and the system variables, whereas in synthesis approach a global view is taken to identify various interactions. … Read more
Since changing the capacity of operating systems can be very expensive, it is important that mining engineers have accurate capacity design tools. Although many modeling approaches have been proposed in the literature, simulation models are widely regarded as providing the most detailed and flexible design approach. Over the last three decades, a number of discrete-event … Read more