Bulk Sample Selection & Preparation
Bulk Sampling The first step in assaying is to obtain a sample, and it is all important that the portion selected should be representative of the entire quantity (Fig. 1). No special pieces should be picked from the bulk, but the desired quantity is taken indiscriminately from the entire original parcel. Crushing Grind or break […]
Rock Crushing
An objective of the present contract is to “provide a concept for the design of a portable underground hard rock crusher in order to insure that future development will lead to maximum utilization by industry”. The preceding section has concluded that the industry can indeed use such a machine and that, within desired performance and […]
Mining Methods VS Underground Crusher Location
In Section 2 we dismissed those “big-room” applications not needing fundamentally new equipment, and lumped all the rest together. Now, as we examine specific mine types, it is appropriate to differentiate within these categories the manner in which portable crushers might be used, and the consequent effect on desired machine parameters. The common yardstick by […]
Portable Rock Crushers
As it relates to portable crushers, the basic portability concept under investigation here might better be described by the phrase ”decentralized crushing to allow automated ore haulage”. Clearly this means more and smaller crushers exhibiting some degree of mobility, and automated ore haulage usually means belt conveyors. The trade-off is a necessarily more costly crushing […]
Determining Mill Tailings Dam Seepage
One of the Bureau of Mines missions is to research the techniques required to achieve structural and environmental control of all mill tailings disposal, both surface and underground. Correlatively, then, the Bureau attempts through advanced practices to reduce jeopardy to life and property. The investigation reported herein stressed the surface-control aspect of this research, whereas […]
How to Make Cupels
Make 200 good cupels, as follows: Take the box used for the purpose and fill with bone-ash, add water and mix. Use as many ounces of water as pounds of bone-ash. The right amount of water has been added when the bone-ash loses its harsh, gritty feeling, and at the same time is not pasty. A […]
Assay Laboratory Instructions
These instruction sheets have been prepared in this form to take the place of mimeograph copies which were formerly used by students electing the course in fire assaying at the University of California. These notes are concise directions for the carrying out of certain laboratory work, and in no wise cover the ground of the […]
Oroville Dam Construction
Thus, 2½ years after completion, the engineering feat of Oroville Dam Construction still loans large. Let us take a close look at this project to see what made it unique. To begin with, it established a number of firsts: At 770 feet it was the highest earth fill dam in the world. At $121 million dollars, […]
Design a Dam for Mill Tailings
More than ever, public opinion is demanding the design of stable embankments as part of tailings disposal systems to aid in abating air and water pollution. Even though many areas have no restrictions requiring industry to impound its tailings, great interest has been generated through universities, industry, and Government in developing sound engineering principles regarding […]
ARSENIC IN GOLD LEACHING
What happens to arsenic during cyanidation depends what form it is in; Stibnite, orpiment, arsenopyrite, realgar. If arsenic is present, regardless of what form, solubility increases with higher pH. Environmentally; during or after detox, the arsenic can be precipitated via ferric sulphate leaching to produce the highly insoluble ferric arsenates which will settle, sometime requires […]