How to Improve Ball Mill Grinding
Functional performance analysis of ball milling has been described previously by Mclvor. “Coarse” versus “fine” or product particle cut-off size is first selected, usually equal to some benchmark passing size of the circuit product (e.g., 80%). The function of the grinding circuit is to generate new product size material (or “fines”) from “coarse” particles in […]
How to Calculate Grinding Mill Operating Efficiency
In grinding, operating Efficiency compares the operating work index of a comminution machine to the Bond work index from bench scale crushing and grindability tests or/and pilot plant tests. Economic Efficiency is comparing the income from production to the planned income from production. Energy as consumed in comminution machines and the required energy as determined, […]
AG & SAG Mills Curved Pulp Lifters
Curved pulp lifters have been incorporated in SAG and AG mills in Australia. The aims have been to ensure complete discharge, at high throughput, of both slurry and coarse solids, especially at high mill rotational speeds. Curved pulp lifters can overcome incomplete discharge and back-flow of solids down the pulp lifter that can occur in […]
AG Autogenous Grinding Power Efficient
The importance of efficient use of power in autogenous grinding circuits has been greatly neglected. It should be the fundamental factor in considering the design of an autogenous plant to grind a particular ore. The steps in the process used to arrive at a power efficient commercial autogenous plant for a particular ore are outlined. Before […]
Rationed Ball Mill Charging to Improve Grinding Efficiency
Ball Sizes As mentioned earlier, years of operating experience indicated that the maximum ball size for the 2.93 m Climax mills was 76 mm. Application of Azzaroni’s equation confirmed that 76 mm was the correct maximum size. The selection of the second, smaller ball size was made by analyzing historical screen analyses representing composite ball […]
Cone Crushing, Rod Milling and Ball Milling Laboratory Testing
The two largest cost components in comminution circuits are energy consumption and metal wear which, for cone crushing, rod milling and ball milling, can be established by conducting laboratory bench scale tests. Pilot plant testing for these comminution methods is not normally required. Laborary testwork performed by Allis-Chalmers to identify these parameters are covered by: […]
Autogenous Grinding & Semi Autogenous Grinding Circuits
Size reduction is the most expensive operation in most mills. Crushing and grinding usually require the greatest portion of capital costs and often make up 60-70 percent of total mill operating costs as shown in Figure 1. Selection of the proper crushing and grinding method must, therefore, be done with great care to be sure […]
Grinding Circuit Simulation
These programs and the simulation algorithms are discussed below. Note that in some Grinding Circuit Simulations, a residence time distribution model is used. In the MRRC simulation package, however, only the two extremes of well mixed and plug flow through the mill are considered. This approach reduces the amount of input information and computation required […]
Laboratory Regrind Mill
A laboratory stirred ball mill was used in a batch manner, with the milling time being varied so as to produce a number of different product size distributions diameter ratio of one, and has a jacket through which cooling water is passed. The vessel is mounted on a turntable which is located on a thrust bearing. The turntable is restrained […]
SAG Semi-Autogenous Mill Steel Consumption
Does a SAG Mill reduce steel consumption? Do SAG mills cost less to operate compared to conventional rod or ball mill grinding circuits? Mining companies are always searching for new ways to cut costs. In order to be competitive and justify the tremendous capital costs of new projects, there has been a strong trend toward […]