Crushing & Grinding Circuit Design – Comminution
The rising costs for and the possibility for limited availability of electrical energy are emphasizing the continual conflict faced in the selection of comminution circuits used in preparing ores for concentration, namely; capital cost vs. operating cost. Frequently, the circuit with the lowest capital cost is not the most efficient in the use of electrical […]
Autogenous and SAG Semi-Autogenous Mill Design Calculations
Mill Sizing: After laboratory and pilot plant testing confirm the feasibility of autogenous or semi-autogenous grinding, it can be used to establish the exact grinding circuit and mill size. In the pilot plant tests, the tare power of the pilot plant mills should be determined before and after each test run. The tare power should be […]
Ball Mill Scale-up Method
Ball Mill Scale-up by this method is known as collision energy based population balance model. The appropriateness of this model is shown for 38-cm ball mill. Comminution in ball mills account for a significant amount of power consumption in mineral processing plants. Therefore, accurate modeling of the process is extremely important to optimize the power […]
Autogenous and Semi-Autogenous Grinding Mill Testing
Ff the drill cores indicate that the ore could contain sufficient lumps in the sizes needed for ore media in autogenous and semi-autogenous grinding, then bulk samples (750 kg) of mine run or primary crushed ore, with an even distribution by quantity in the size fractions between 100 mm and 200 mm, should be obtained […]
Grinding Media Corrosion Rate
While grinding is unavoidable in nearly all mineral processing, it is an inefficient and costly step. As an example, the National Academy of Sciences (NAS) estimates that the copper industry consumed 205,000 tons of grinding media in 1978. A typical copper producer processing 100,000 tons of ore per day may spend approximately $25,000 daily to […]
How to Size a Rod Mill Grinding Rod Diameter
Effect of Rod Mill Feed Sizing on Grinding Performance
There is no reported evidence that feed size has any effect on rod mill power draw. Because the solids in the rod mill are known to appreciably expand the mill charge (as observed in the charge level before and after grinding out the mill), there would likely be a tendency for power draw to be […]
SAG Mill Feed Particle Size Analyser
We describe here one of the very first pioneering SAG Mill Feed Particle Size Analysers: A set of preliminary experiments was carried out in order to assess the hardware-software’s behaviour. Static ore was used to obtain the right sequence of image processing algorithms. The camera was installed 3 mts away from the commercial sizer over […]
Porous Structure of Ball Charge in Grinding Mills – Hydrodynamics of Slurry Flow
In this work, the slurry flow in the ball mill is solved with Navier-Stokes’ equations and the marker and cell technique (MAC), which tracks the fluid-free surface. Considering different planes in the radial and axial directions, this numerical approach leads to the direct calculation of the slurry velocity profile, mill holdup, and volumetric flow in […]
Simulation to Aid Process Design and Plant Optimization
The Kori Kollo Project is located in Bolivia, approximately 220 km south of La Paz, and 40 km northwest of Oruro. It is owned and operated by Empresa Minera Inti Raymi S.A. (IRSA), an 85% owned subsidiary of Battle Mountain Gold Company. Following a feasibility study and preliminary engineering by others, Minproc was awarded a […]