How to Calculate Grinding Mill Operating Efficiency
In grinding, operating Efficiency compares the operating work index of a comminution machine to the Bond work index from bench scale crushing and grindability tests or/and pilot plant tests. Economic Efficiency is comparing the income from production to the planned income from production. Energy as consumed in comminution machines and the required energy as determined, […]
Placer Prospecting
Placer Prospecting Practice Prospecting methods have been developed and well established within the last few years. Sinking pits and shafts generally gives good results, but this work is usually expensive and generally slow and troublesome, owing to the presence of water in most placer ground or to the necessity of timbering the shafts. With the […]
Hydraulic Mining Equipment
Hydraulic Mining Where it is practicable, this is the simplest and most inexpensive method of placer mining. The mechanical equipment requirements consist only of pipe lines and giants. One feature, however, that is frequently overlooked in hydraulic mining is the matter of dumping facilities. This should always receive careful consideration. It often happens that there […]
Placer Gold Dredges
Steam Electric Dredge There can be no question that the most efficient and economical method of operating a dredge is to have all the units electrically driven by individual motors and where electric power is available, the question of motive power presents no difficulty. Where such power is lacking and a self-contained steam driven dredge […]
Dredge Mining for Gold
A Modern Idea of Service Our present plant was designed and built by ourselves and we have also designed and built much of our special machinery in order to take care of the operations peculiar to our line of work. Our plant is electrically operated throughout and every modern method and apparatus has been installed […]
Hindered Bed Classifier Modelling
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 […]
Rare Earth Magnetic Separators
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 […]
Copper Solvent Extraction Pulsed Column
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 […]
Chalcopyrite Chlorination Process for Copper Extraction
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 […]
Evaluate Underground Pillar Stress
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 […]