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Grab Sampling in Mining & Drilling

Grab sampling usually consists in taking portions of ore at random from muck piles, chutes, or the tops of cars of ore. When done in this manner it is a haphazard method that can be relied upon only for roughly approximating the grade of the ore and often is employed merely for that purpose. The … Read more

How to Subsample a Large Bulk Sample or Soil, Ore, or Rocks

Before assaying, original samples must be cut down, often in several stages. Each cut involves, in effect, the sampling of a sample, the final portion comprising only the ore that actually goes into the crucible or flask and upon which the actual determinations are made. In cutting down samples to reduce the bulk to the … Read more

Mining Animation

https://www.911metallurgist.com/blog/gold-extraction-processes

Sampling of Gold Bullion for Quality Control – Elemental Analysis

At the Seventh International Congress of Applied Chemistry I presented a paper, The Assay and Valuation of Gold-Bullion, in which are briefly mentioned a few illustrations of different methods of sampling gold-bullion, particularly cyanide-bars. Since then I have carried on an extensive investigation upon the sampling of gold-bullion in relation to its effects upon the … Read more

Precipitate Gold Mercury with Electricity

The treatment of slimes has of late years been, the chief difficulty in connection with cyanide work, in which much time and money has been spent in endeavouring to find a practical solution of this problem. The processes at present in use are: Filter pressing, as practised in Western Australia. Decantation, as practised in South … Read more

How Bismuth Affects Brass Quality

It is a tradition in the brass industry that bismuth is an injurious element in brass, even more deleterious than antimony; but such a belief has lacked verification. The occasional presence of bismuth in commercial copper (although less frequent than was formerly supposed) led the author to investigate this tradition. The following experiments were conducted … Read more

Plunger Jig & Accelerated Jig

In the discussion of my paper on “ Close Sizing Before Jigging,” Mr. Louis remarks: “ What we really need to know as the basis of any consistent theory (of jigging) is what occurs during each hundredth of a second.” It is clear that for the further study of the laws involved, a jig-tester is … Read more

Variable Speed Pulley

Every constructing engineer and designer knows how often it is desirable to provide a speed-adjustment between parts of a machine performing different functions, or between a prime mover and the devices to which it furnishes power, and how bulky and unsatisfactory are most of the methods by which the result is usually accomplished. Of course … Read more

Electrical Accumulators or Storage Batteries

The broad general distinction between primary and secondary batteries lies in the fact that in the former the current is produced by the consumption of one or both of the elements composing the cell, while in the latter the elements retain their form as such, and merely pass from one state of chemical combination to … Read more

Magnetite Processing & Extraction Jig

This Conkling Jig (ore-concentrating machine or jig), as it is called, is not entirely unknown, having been used at several places with more or less success; but as yet, I believe, no drawings of it or records of its work have found a place in print. Although the jig will be found to be merely … Read more