Grinding Circuit Expansion
Increasing ore hardness led to a gradual reduction of mill throughput rates. This, combined with declining head grades and low gold price, prompted a review of milling practice at Kidston. Plant trials and computer simulation of the grinding circuit indicated the potential to increase mill throughput by up to 45% by reducing SAG mill feed […]
AG & SAG Mill Grinding Circuit Automatic Control
It is obviously well understood that autogenous AG and semi-autogenous SAG mills operate quite differently from conventional rod mill or ball mills. Since these mills are of a grate discharge type, they operate with varying loads, with the power drawn by the mill being dependent upon the volumetric load within the mill and factors that […]
SAG Mill Availability Targets
Keeping a SAG mill running well and “all the time” does not come easily nor does it come equally to everyone. “OK” = 90% Good = 92% Great = 94% Exceptional 95% Only one operation, located in Chile, is known to be at 95%. ** Thanks to Alex at SAGmilling.com for this intel.
How much Gold can an iCON Gravity Concentrator Recover
How much gold you can recover depends much more on your ore mineralogy than on the iCON Gravity Concentrator itself. Gravity Recoverable Gold (GRG) A three stage Gravity Recoverable Gold test was conducted on a gold ore sample. From Stages 1 to 3, the sample was staged crushed/ground to 850µm K100 (20 mesh), 212µm K80 […]
Turbomilling Comminution of α-SiC Silicon Carbide
Interest has been increasing in recent years in structural materials that can withstand severe conditions of temperature, pressure and environment, and can substitute for high-temperature alloys that require imported materials such as chromium, cobalt, and nickel. As a result, the utilization of ultrafine, high-purity ceramic powders in advanced and composite ceramics is increasing. Nonoxides such […]
Grinding Mill Liner & Ball Corrosion Rate
Several wear mechanisms act upon the grinding media, including corrosion, abrasion, and impact. The interactions between these wear mechanisms are poorly understood, and much disagreement exists in the technical literature. To determine the extent to which corrosion contributes to total wear in industrial grinding mills, the Bureau of Mines entered into cooperative agreements with two […]
Grinding Cement Clinkers
Most Cement Clinkers grinding experiments were carried out in a 29.2 cm diameter laboratory ball mill which had a built-in wavy liner. The ball charge consisted of 1.27, 1.90 and 2.54 cm steel balls mixed in equal proportion by number. The ball load corresponded to 40% filling of the struck volume of the mill (denoted […]
Modelling and Control of Ball Mill Grinding
Dynamic experiments were performed in a continuous open-circuit 40×40 cm ball mill using a pseudo-random binary sequence of the feed rate and measuring the variations of the discharge particle-size distribution. The impulse response is calculated by a cross- correlation technique. Then a model involving a discrete transfer function and a time-series stochastic equation is calibrated […]
How to Save Power in Cement Grinding
For grinding Portland Cement, the power consumption accounts for some 35% of the total consumption of electrical energy for producing cement, counting right from the quarry to the packing plant. It is therefore for very good reason that great efforts during the past years have been put into making cement grinding more efficient, thereby saving […]
Chemistry of Mineral Slurry Rheology Control Grinding Aids
Tests run on using organics to influence the fracture strength of solids gave an almost bewildering array of results on the four substrates. Two general classes of tests were carried out: 1) a procedure consisting of introducing a notch in a small rectangular sample, placing this sample in an environmentally controlled chamber for humidity, chemical […]