To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

4,5
Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
Live Statistics
English Articles
Improved in 24 Hours
Added in 24 Hours
Languages
Recent
Show all languages
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.
.
Leo
Newton
Brights
Milds

From Wikipedia, the free encyclopedia

Typical arrastra construction. From Mining and Scientific Press 52 (1886): 237.
Arrastra demonstration in Liberty, Washington, 2007

An arrastra (or arastra) is a primitive mill for grinding and pulverizing (typically) gold or silver ore. Its simplest form is two or more flat-bottomed drag stones placed in a circular pit paved with flat stones, and connected to a center post by a long arm. With a horse, mule or human providing power at the other end of the arm, the stones were dragged slowly around in a circle, crushing the ore.[1][2] Some arrastras were powered by a water wheel; a few were powered by steam or gasoline engines, and even electricity.[1]

Arrastras were widely used throughout the Mediterranean region since Phoenician times.[1] The Spanish introduced the arrastra to the New World in the 16th century. The word "arrastra" comes from the Spanish language arrastrar, meaning to drag along the ground.[2] Arrastras were suitable for use in small or remote mines, since they could be built from local materials and required little investment capital.[2][3]

For gold ore, the gold was typically recovered by amalgamation with quicksilver. The miner would add clean mercury to the ground ore, continue grinding, rinse out the fines, then add more ore and repeat the process. At cleanup, the gold amalgam was carefully recovered from the low places and crevices in the arrastra floor. The amalgam was then heated in a distillation retort to recover the gold, and the mercury was saved for reuse.[3]

For silver ore, the patio process, invented in Mexico in 1554, was generally used to recover the silver from ore ground in the arrastra.[citation needed]

YouTube Encyclopedic

  • 1/3
    Views:
    142 625
    367 978
    939 621
  • New Electric - The converted Electric Tractor that pulls 30 tonnes
  • Ventilador no arranca pero el motor si suena SOLUCIONADO 2023
  • síntomas de un motor de arranque dañado

Transcription

References

  1. ^ a b c Van Bueren, Thad M. (2004). "The 'Poor Man's Mill': A Rich Vernacular Legacy". IA, The Journal of the Society for Industrial Archeology. 30 (2): 5–23. JSTOR 40968663.
  2. ^ a b c "Gentry Gulch Arrastra". Groveland Yosemite Gateway Museum. Archived from the original on 2011-10-04. Retrieved 2011-03-22.
  3. ^ a b Cooke, Ron. "What is an Arrastra?". Plumas County Adventures. California State University-Chico. Archived from the original on September 16, 2016.

External links

This page was last edited on 5 April 2024, at 14:52
Basis of this page is in Wikipedia. Text is available under the CC BY-SA 3.0 Unported License. Non-text media are available under their specified licenses. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. WIKI 2 is an independent company and has no affiliation with Wikimedia Foundation.