Mill Trunnion Liner
The Mill Trunnion Liner fits inside the bearing to protect it from wear caused by the ore being washed over the liner and through the bearing as it is fed to or discharged from the mill. The difference in the trunnions at each end of the mill isn’t in the trunnions themselves. The trunnion liner on the […]
Trunnion Bearing Assembly Ball Mill & Rod Mill
The first part of the mill that we will look at is the TRUNNION BEARING. This is a HYDROSTATIC BEARING which is a slow moving bearing that carries a heavy load. Usually it is constructed from Babbitt’s metal. If you happen to remember the introduction to this course Issac Babbitt was the man who devised the […]
How to do a Sieve Analysis
Let me explain as to how a Sieve Analysis is done. If you take a sample of ground ore, heat it until it is completely dry. Take 500 grams of that sample, and place it on top of a set of screens designed for size analysis. These screens have a graduated mesh size. The screen […]
Grind to Liberate Mineral Grains
The next piece of information that is of value to the operator is to know the hardness of the ore. The WORK INDEX, as the hardness is referred to, is calculated on the amount of electrical energy that is required to grind the ore to a predetermined size. Said in another way, it is the […]
Rods or Balls
Mill operators will not get to design too many mills, but this doesn’t mean that the information that has been compiled isn’t of interest to the operator. Knowing the ore body shape, size, and content will give the operator prior knowledge of operating conditions to be expected. It is also beneficial to know how this […]
Simple Grinding Circuits & Flowsheets
To start the discussion on grinding circuits I would like to begin by showing you some simple Flowsheet SCHEMATICS of some sample circuits, but before I do there is one thing that I must explain for the schematics to make sense. When the ore is put into the first piece of equipment for grinding, water […]
Ore Bin (Silo) Safety
Around these ore storage bins or areas there are three possible places of work, on top, under, and in. Each one has their own brands of danger, and methods of safety and protection. The dangers of working under these areas are MOVING EQUIPMENT, PRYING ON HANGUPS, STANDING’ON EQUIPMENT and SMALL PLATFORMS WITH LITTLE HEAD ROOM. That […]
Fine Ore Storage Bin and Stock Pile
Let’s begin with fine ore storage bin or stockpile, get it out of the way and then proceed to grinding. You would think that there isn’t that much to learn about when talking of fine ore storage, after all, all that this area is really for is to provide surge capacity for each of the […]
Vibrating Screens & Safety
Around Vibrating Screens, the 2 primary Safety considerations to have in mind are NOISE and DUST. These two are harder to deal with than most because of their nature. A hazard that involves blood and pain is an immediate thing and very easy to understand. But something that may take years of development before it […]
How Mine Trash affects Crushers
Am talking about circulating garbage! In every crushing plant there are objects other than rock put into the feed. It may be rubber, from the tires of the mining equipment. It could also be wood or wire that was accidently put into the coarse ore feed. This type of refuse is too large to go through […]