Small electric dredges are great where water power is available within reasonable distance, electricity may be generated and transmitted by cable to the dredge, proving an economical substitute for steam, especially in localities where fuel is dear. The small space, too, occupied by the plant, and the ease with which it is handled, make electricity … Read more
The first steam dredge of the bucket type was launched on the Clutha in 1881. Such dredges differ from current-wheelers only in being provided with engine and boiler in place of the undershot wheel. The use of steam machinery, of course, increases the initial cost, adds to the working and maintenance expenses, and necessitates the … Read more
In the Current-wheel Dredge, the mechanism on these dredges is driven by an under-shot water-wheel, placed at one or at both sides of the scow and rotated by the current. Such dredges work with most safety and regularity in about a 3-knot current. An instance of a machine of this kind is the Mannherikia dredge, … Read more
Dredge Hull Among dredging hands, the “ hull ”—namely, “ port ” and “ starboard ” pontoons tied together—is usually termed the “ pontoon ” or “ pontoons.” The ordinary hull consists of two long, narrow pontoons, joined together for about a third of their length by a third small one, equal in width to … Read more
In its primitive form, the dipper dredge consists of a barge or pontoon, to the side of which is attached a long pole carrying a strong canvas or hide bag, or iron bucket, which is termed a ladle, spoon, scoop, or dipper, and which at times is provided with a blade or shovel. To the … Read more
The Paddock pneumatic ore separator is a jig, in which air is used instead of the fluid more commonly employed—water. Like the water jig, it consists of an inclined sieve, over which the crushed ore is passed, and through which the air is blown into the ore. The air current is intermittent, and being proportioned … Read more
I desire to call the attention of the Institute to a novel system of dredging, which, it seems to me, may prove applicable, not only to river and harbor improvements, but also to certain varieties at least of alluvial and diluvial gold mining; that is, river-mining, bar-mining, coast-mining, and any other similar operations now carried … Read more
For some years past the principle enunciated in the discussion referred to has been known to the writer and demonstrated by him to be an efficient and economical way of separating water or solution from solids in the cyanidation, lixiviation or acid leaching of ore pulps. In utilizing this principle in commercial practice he has … Read more
In a tin concentrator an appliance was needed to furnish a suitable product for fine jigging from a pulp of the following composition: In the jigging process, particles of cassiterite as small as 0.1 mm. can be recovered, provided they are not present in excess, that is if the material treated on the jigs contains … Read more
Discovery of Gold Bearing Gravel in Canada A woman first discovered gold in the Chaudiere Valley near the mouth of Gilbert River. No attention was paid to the discovery, but a young girl named Clothilde Gilbert, taking a horse to water, found in the creek, close to the location of the previous discovery, a nugget of gold … Read more